| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 560.1 | GALILEO Topics 280 and 391 | CLIPR::KLAES | N = R*fgfpneflfifaL | Fri Aug 25 1989 15:29 | 5 |
| Discussions and information on the GALILEO probe to the planet
Jupiter can also be found in SPACE Topics 280 and 391.
Larry
|
| 560.2 | GALILEO details in August issue of CANOPUS | RENOIR::KLAES | N = R*fgfpneflfifaL | Wed Sep 13 1989 13:46 | 172 |
| GALILEO FINALLY GETTING "OFF THE GROUND" - can890815.txt - 8/21/89
Preparations for the Oct. 12 launch of the Galileo mission to
Jupiter are proceeding on time as the spacecraft gets the closest it
has been to launch since the January, 1986 Challenger accident.
The only major problems that have occurred have been with the main
command and data system (CDS) computer, which delayed its final
installation, and with the 10-newton attitude control thrusters, which
will have to be operated in pulses rather than steady firings.
Officials at the Jet Propulsion Laboratory briefed reporters on
the "extremely complex mission" Sunday afternoon as they covered the
Voyager encounter with Neptune.
Project Scientist Torrance Johnson caled Galileo "a mission to the
entire Jovian system" and said that although the inner solar system
and asteroid encounters are secondary, "We think we can do an awful
lot of exciting science" along the way to Jupiter.
Galileo's launch date has been on-again, off-again as it has been
fitted for an array of different upper stages over the past decade
(the 8/89 issue of Aerospace America describes this saga in detail).
Because of these problems, Galileo now is slated to be boosted by
a conventional Inertial Upper Stage to Venus for a complex
Venus-Earth-Earth Gravity Assist (VEEGA) trajectory that will bring
the Galileo orbiter and atmospheric probe to Jupiter in December 1995.
As he showed a tape of Galileo being hoisted for mating to its
IUS, like that used for Magellan earlier this year, Project Manager
Richard Spehalski noted that "this is the furthest that Galileo has
gotten off the surface of the Earth at this point."
The orbiter was shipped to Kennedy Space Center without its main
computer, Spehalski said, because a number of solder joints were found
to be susceptible to cracking. Although some of this was caused by the
many retests since the 1986 launch delay, officials said that there
would have been serious problems had Galileo been launched in 1986.
The other major problem that has been encountered was the
discovery that the 10-newton thrusters supplied by West Germany cannot
be fired for long periods. This was discovered with nearly identical
thrusters aboard the German TV-Sat communications satellite. Despite
that and a 15 percent increase in the number of maneuvers, Spehalski
and Johnson expect that the impact to the science mission will be minimal.
Mating with the IUS and interface tests with the stage have been
completed, he said.
Mission Director Neal Ausman said the plutonium fuel for the
radiothermal isotope generators (RTG's) will be loaded into the
spacecraft at the launch pad at L-6 days. He also said that the
spacecraft will be relatively passive throughout most of the launch,
unlike Magellan which had an extensive check-out procedure before
deployment.
The data management system tape recorders will be started at T-3
hours, and the heaters will be turned on as soon as the Shuttle payload
bay doors are open. A power sharing routine will be started aboard the
spacecraft at T+5:55 when the Shuttle quits cooling the RTGs.
Galileo is to be deployed at T+6:20 and the IUS ignited about 45
minutes later.
Officials said that no Shuttle retrieval mission will be attempted
should the IUS fail to fire, stranding Galileo as the European
Hipparcos mission has been. Retrieval is considered too hazardous,
they said.
Not until separation from the IUS after second-stage burnout will
the spacecraft become active and attempt contact with the Deep Space
Network. The separation sequence and radio activation will come at
T+7:37.
During the first seven days the spacecraft systems, including the
solid-state imaging camera and the near-infrared mapping spectrometer,
will be commanded in real time to check them out while high data rates
are still possible with DSN. The high gain antenna will not be
deployed until after the second Earth gravity assist (when Galileo is
out of the inner solar system), so this will be the only chance engineers
have to test equipment extensively until the outbound cruise to Jupiter.
At L+21 days the first of several trajectory correction maneuvers
(TCM-1) is scheduled. Ausman said "the complexity of the maneuvers was
a bit of a surprise," and they will have to be handled carefully until
the plume impingement characteristics of the attitude control
thrusters are well known. The 400-newton main thrusters will not be
available until after the probe is deployed.
Each TCM will comprise several firing cycles, each including:
3 hours of preparation,
8.3 hours of maneuvering segments, each up to 48 minutes at a time, and
30 minutes to return to cruise configuration.
Ausman said that four in a row can be performed, at which point the
ground team must rest. TCM-1 will take a total of 12 days to complete.
Once in orbit around Jupiter, Galileo will use the gravity of the
Galilean moons to crank its orbit for a series of encounters in a
mini-grand tour of the Jovian system. Because of the radiation hazard
-- which will take about half the spacecraft's "lifetime dose" -- only
one encounter of Io is planned, and that on the inbound leg before
orbital insertion.
The exact pattern for Galileo's tour of the moons of Jupiter will
not be decided until after launch since delays will affect the arrival
date (a delay of a week will also eliminate the margin for the Gaspra
asteroid encounter in 1991).
The tour of the Jovian moons -- primarily the Galilean moons -- is
to last about 20 months. Options for an extended mission include
cranking the orbit to higher inclinations to observe the polar regions
or Jupiter, polar passes over the moons, or a "death plunge" into Io,
the volcanic moon.
LONG PLANETARY "DATA STREAM" ABOUT TO START, KELLER SAYS -
can890824.txt - 8/30/89
A stream of planetary data that will last into the 21st century is
about to begin, NASA Associate Deputy Administrator Sam Keller told
reporters Tuesday afternoon at Marshall Space Flight Center in
Huntsville, Ala.
He also said that NASA will try not to overcommit itself to
experiment programs as it did during the late 1970s and early 1980s.
In reviewing the future of planetary exploration, Keller said that
with Magellan (Venus), Galileo (Jupiter), and Ulysses (solar
interplanetary) launched or about to be, and with other planetary
spacecraft planned or in development, "the U.S. will have a continuous
stream of data to the year 2006."
But those spacecraft will be targeted to orbit specific bodies
rather than playing interplanetary billiards.
"The chances of returning to the moon of Triton, as exciting as it
was, are not very good now" he said, and would probably rely on a
high-energy mission with a single gravity assist at Jupiter.
When asked whether the science community would see on Space
Station a repeat of the "Famous 40," Keller said that, "We will try
not to pick what we can't fly."
The "Famous 40" refers to Shuttle/Spacelab payloads selected in
the late 1970s. Most have not flown on Shuttle and at least one
appears to have been recycled for Space Station.
"We will attempt to honor the commitments that have been made," he
said, and "not make any committments that cannot be honored in a
particular time."
Among other topics that Keller discussed with reporters:
Most of the talk during the Voyager/Neptune encounter centered on
President Bush's initiative to return to the Moon and go to Mars.
A joint manned Mars mission with the USSR cannot be decided for at
least another decade since it will take that long to get such an
effort into early planning following Space Station and the Moon.
Meanwhile, joint efforts involving the Mars Observer, ozone mapper on
Meteor 3, and gamma-ray burst detector on the International
Solar-Terrestrial Physics program are providing the "first
engineer-to-engineer discussions" between the two nations.
The Mars Observer still costs less than an all-new mission despite
cost growth that has gone far beyond the "production line" spacecraft
concept. Keller admitted NASA was "overly optimistic" on how low the
price could be held, but said that "the goal of not reinventing the
wheel is one that we should not lose sight of."
|
| 560.3 | Dial the ATLANTIS | RENOIR::KLAES | N = R*fgfpneflfifaL | Fri Sep 15 1989 22:08 | 56 |
| From: jordankatz@cdp.UUCP
Newsgroups: sci.space
Subject: NSS Dial-A-Shuttle Release
Date: 15 Sep 89 10:23:09 GMT
Eavesdrop on Space Shuttle Atlantis by calling the National Space
Society's Dial-A-Shuttle (1-900-909-NASA) program as the astronauts
deploy NASA's Galileo spacecraft during the STS-34 mission scheduled
for launch on October 12.
Callers to Dial-A-Shuttle will hear up-to-the-minute live reports,
interviews and features about the STS-34 space shuttle mission and
crew as well as live astronaut communication as it is available.
The primary mission of the astronauts aboard the Atlantis will be
to deploy a three-ton spacecraft called Galileo which will make a six
year voyage to the planet Jupiter. Galileo's unique design includes
both an orbiter and an atmospheric probe, enabling scientists to study
for nearly two years Jupiter's atmosphere, its moons, and the
surrounding magnetosphere.
After leaving Atlantis' payload bay, the spacecraft will be
boosted out of Earth orbit by a solid rocket. Galileo will first fly
past Venus and then twice by Earth, using gravity assists from the
two planets to pick up enough speed to reach Jupiter, which is five
times further from the Sun than Earth. The two extraordinary Earth
encounters, which will occur in 1990 and 1992, will provide the first
ever deep space look at our own planet.
The commander of the STS-34 mission is U.S. Navy Capt. Donald E.
Williams, the pilot is U.S. Navy Cmdr. Michael J. McCulley, and the
mission specialists who will deploy the satellite as well as conduct
other experiments are Dr. Shannon W. Lucid, biochemist, Dr. Franklin
R. Chang-Diaz, physicist, and Ellen S. Baker, M.D.
The Jet Propulsion Laboratory in Pasadena, California has prepared
the Galileo spacecraft for NASA. The spacecraft and its mission are
named for 17th-century Italian Renaissance scientist Galileo Galilei
who discovered Jupiter's major moons with the first astronomical telescope.
Dial-a-Shuttle is a special service offered by the National Space
Society (NSS), a nonprofit, publicly-supported membership organization
dedicated to the creation of a spacefaring civilization. The Society
has more than 22,000 members and 120 chapters, conducts annual
conferences, operates the Space Phone Tree and the NSS Computer
Bulletin Board Service and publishes AD ASTRA magazine.
The toll charge for this call is $2.00 for the first minute and 45
cents for each minute thereafter.
For more information about the Society and their exciting programs, write:
NSS, 922 Pennsylvania Ave., S.E., Washington, D.C. 20003-2140
Telephone: (202) 543-1900
|
| 560.4 | Legally stop a shuttle launch ? | CRATE::CLIFFE | Howl at the Moon | Mon Sep 18 1989 12:42 | 21 |
|
In this Sundays UK Observer newspaper, (a respectable one),
it mentions a legal attempt by Christic Institute (who they?) and
Florida Coalition of Peace and Justice to halt the shuttle due to
fears that an explosion could distribute about 50lbs of plutonium
around the area.
The reactor for Galileo, an "radio-isotope thermo-nuclear generator"
(RTG) is the first one to be launched by a shuttle. (this true?)
NASA claims that in any launch accident the release of plutonium
is 1-1,460 while the DoE suggests 1-430.
What safeguards are they for containing the plutonium ?
I would assume that the chances of them actually stopping the launch
would be zero, but is this an issue that is going to get bigger?
Do these people have any clout or is this just media hype ?
Information gleened from the odd paragraph we get in the U.K. papers
about shuttles etc. Thanks for this notesfile !
|
| 560.5 | Nuclear Paranoia | VOSTOK::LEPAGE | Truth travels slowly | Mon Sep 18 1989 14:12 | 18 |
| Re:.4
The 50 pounds of plutonium in Galileo's RTGs are contained in
several different ways. The plutonium itself is in the form of
plutonium dioxide and is a very dense and durable ceramic.This ceramic
is then encased in a couple of containment vessels designed to
withstand immense shocks and reentry level temperatures (in fact a
couple of similar RTGs have survived reentries on aborted launches of
ELVs and one was actually recovered and reused). The chances of the
plutonium being pulverized into a powder and dispersed by the wind (the
worst thing that could happen) are very slight. Even a Challenger-like
accident would be unlikely to breach the RTG container. The Florida
Coalition and other groups trying to stop the launch is just another
example of the nuclear-paranoia that has wiped out the nuclear industry
in the US.
Drew
|
| 560.6 | STS-34 will launch as scheduled; worries about Hugo | RENOIR::KLAES | N = R*fgfpneflfifaL | Mon Sep 18 1989 21:43 | 66 |
| Newsgroups: sci.space
Subject: NASA Headline News for 09/18/89 (Forwarded)
Date: 18 Sep 89 19:10:33 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
NASA Headline News
Monday, Sept. 18, 1989 Audio: 202/755-1789
-----------------------------------------------------------------
This is NASA Headline News for Monday, September 18:
Officials at Kennedy Space Center are closely watching Hurricane
Hugo as it churns west-northwesterly in the southern Carribean. The
Class Four storm could threaten the East Coast of the U.S. with
extremely high winds and heavy rains. If the storm zeros in on
Florida it could force NASA to roll the Atlantis back from the launch
pad to the Vehicle Assembly Building. Cape personnel are developing a
contingency schedule in the event the storm heads for Florida.
The White House has approved the launch of the Galileo spacecraft
aboard the Atlantis. The Executive Office decision was required
because Galileo carries Radioisotope Thermoelectric Generators...RTGs...
that use nuclear material to generate electrical power for the spacecraft.
A coalition of anti-nuclear activists says it will file suit to stop the
launch. They claim a catastrophic launch failure could release nuclear
material that would endanger the health of people in central Florida.
The protest group says they will carry their protest all the way to the
launch pad, if necessary.
Following completion of the Terminal Countdown Demonstration Test
last week, the crew of the Atlantis flew to Washington, Saturday, for
a breakfast visit with Vice President and Mrs. Quayle. Mr. Quayle,
Chairman of the National Space Council, said he will be at the Cape
for the launch of the Atlantis to underscore the fact that there is no
danger from the RTGs during launch.
-----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select television. All times are Eastern.
Wednesday, September 20......
2:00 P.M. Briefing on launch of FltSatCom aboard an
Atlas-Centaur from KSC.
Thursday, September 21.....
11:30 A.M. NASA Update will be transmitted.
Friday, September 22......
3:00 A.M. NASA Select programming begins for FltSatCom
launch at KSC. Launch window opens at 4:15
A.M.
All events and times are subject to change without notice.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA
Headquarters, Washington, D.C.
|
| 560.7 | | COMET::MONTGOMERY | Drawing a Blank | Tue Sep 19 1989 19:18 | 15 |
| >If the storm zeros in on
>Florida it could force NASA to roll the Atlantis back from the launch
>pad to the Vehicle Assembly Building.
How Long does this take??? And what type of delays would happen if
they did??
>The protest group says they will carry their protest all the way to the
>launch pad, if necessary.
At T-5sec I hope they still standing there... ;^)
Monty
|
| 560.8 | The Delay | VOSTOK::LEPAGE | Truth travels slowly | Tue Sep 19 1989 19:38 | 12 |
| Re:.7
It takes about 48 hours to prepare the Shuttle to move and actually
move it to the VAB (the things to be done are listed in 391.19).
As far as the delay to the launch of Galileo I'm not too sure. It
all depends how much pad damage there was from the storm, how many
items on the check lists have to be redone, and so on. Depending on
where they are in the cycle, the delay could be as little as a week or
as much as three weeks (hopefully not much more otherwise the launch
will have to be delayed for another 13 months!).
Drew
|
| 560.9 | STS-34 and Hurricane Hugo update | RENOIR::KLAES | N = R*fgfpneflfifaL | Wed Sep 20 1989 12:33 | 14 |
| KSC SPACE SHUTTLE PROCESSING REPORT - TUESDAY, SEPT. 19, 1989
STS-34 - ATLANTIS (OV 104) - PAD 39-B
Preparations are underway to button up the orbiter for adverse
weather or for a roll back to the Vehicle Assembly Building. The
payload bay doors are scheduled to be closed this morning, platforms
are being retracted and loose items are being secured. Servicing and
testing of the cooling system for GALILEO's radioisotope thermoelectric
generators was completed yesterday. Deservicing of that cooling system
is scheduled today. Earlier today, one of the two crawler transporters
was moved to the Pad B gate in the event a decision to roll back to the
VAB is made. That decision is expected tomorrow.
|
| 560.10 | STS-34 Update - September 20 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Sep 21 1989 13:41 | 31 |
| Newsgroups: sci.space
Subject: NASA Headline News for 09/20/89 (Forwarded)
Date: 21 Sep 89 00:24:39 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
NASA Headline News
Wednesday, Sept. 20, 1989 Audio: 202/755-1788
-----------------------------------------------------------------
This is NASA Headline News for Wednesday, September 20:
As Hurricane Hugo continues to move in a northwesterly direction
towards the U.S. East Coast, Kennedy Space Center launch officials
have decided not to make a decision yet on moving the Space Shuttle
Atlantis back to the Vehicle Assembly Building. Launch Chief Robert
Sieck says that KSC will maintain a posture to allow for a 24 hour
move, but personnel are continuing launch processing activities.
There are indications the storm will come ashore well north of the
Cape Canaveral area. But, as part of contingency plans, the Solid
Rocket Booster on Mobile Launch Platform-3 was removed yesterday and
the platform itself moved out of the Vehicle Assembly Building to make
way for the STS-34 stack, if necessary.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Commiunications Branch (LPC), NASA
Headquarters, Washington, D.C.
|
| 560.11 | ATLANTIS will not be moved due to Hugo | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Sep 21 1989 18:25 | 84 |
| Newsgroups: sci.space,sci.space.shuttle
Subject: NASA Advisory: STS-34/Hurricane Hugo Update (Forwarded)
Date: 21 Sep 89 16:07:01 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
Sarah Keegan
Headquarters, Washington, D.C. September 21, 1989
NASA ADVISORY: STS-34/Hurricane Hugo Update
Shuttle program managers have concluded that there is no credible
scenario relative to hurricane Hugo which would require a rollback of
Atlantis to the Vehicle Assembly Building at Kennedy Space Center,
Fla., and therefore, have decided that the vehicle should remain on
the launch pad.
For about the next 12 hours, KSC personnel will be preparing to
resume work readying Atlantis for launch. During this time, officials
will continue monitoring the weather to determine if the pad area
might see winds of a velocity which would require a "ride out"
configuration, although this is not forecast. This period also will
provide an opportunity for rest for the KSC work crews.
Newsgroups: sci.space
Subject: NASA Headline News for 09/21/89 (Forwarded)
Date: 21 Sep 89 16:59:25 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
Thursday, Sept. 21, 1989 Audio report: 202/755-1788
-----------------------------------------------------------------
This is NASA Headline News for Thursday, September 21st:
After a weather briefing early this morning, Shuttle program
mangers have concluded that hurricane Hugo no longer poses a severe
threat to Kennedy Space Center. Early this afternoon technicians will
begin reconnecting fuel lines and electrical cables prior to resuming
normal launch processing. The processing had been running ahead of
schedule and at the end of last week, there were five full days of
"contingency time" available to handle unexpected problems.
Processing Director Conrad Nagel said those five days were being used
up this week by the rollback preparations. Atlantis is currently
scheduled for launch on October 12.
A hearing will be held today in Richmond, Virginia Circuit to
determine whether the state should enforce a request by the Attorney
General to temporarily shut down Avtex Fibers, Inc. The state
maintains Avtex continues to discharge large amounts of PCBs into the
Sheandoah River. Avtex is the sole supplier of a rayon fiber used by
NASA and the Defense Department in solid rocket motors. Both agencies
said yesterday that they had no plans to intervene on Avtex's behalf.
-----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select television. All times are Eastern.
Friday, Sept. 22.....
11:30 A.M. News briefing on the FltSatCom launch from
Kennedy Space Center.
Monday, Sept. 25.....
3:00 A.M. NASA Select TV coverage begins of FltSatCom
launch at KSC. Launch window opens at 4:12
A.M., Eastern.
Thursday, Sept. 28...
11:30 A.M. NASA Update will be transmitted.
1:00 P.M. Galileo-probe briefing from Ames Research
Center.
All events and times are subject to change without notice.
-----------------------------------------------------------------
These reports are filed daily Monday through Friday at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA Hdqs.
|
| 560.12 | STS-34 Status - September 21 | RENOIR::KLAES | N = R*fgfpneflfifaL | Fri Sep 22 1989 14:52 | 31 |
| KSC SPACE SHUTTLE PROCESSING REPORT - THURSDAY, SEPT. 21, 1989
STS-34 - ATLANTIS (OV 104) - PAD 39-B
Based on the uncertainty of Hurricane Hugo's track last
night, shuttle managers decided to stop the main engine flight
readiness test and to disconnect Atlantis and its launch platform
from the Pad to prepare for a possible roll back to the Vehicle
Assembly Building. This morning's weather forecast indicates that
KSC will not be threatened by the hurricane. Earlier today,
Hugo's location was about 270 miles east to northeast of KSC.
Some rain is expected this afternoon and peak winds are predicted
to be 20-40 knots - within the limits for the vehicle.
The Rotating Service Structure (RSS) was moved away from the
vehicle early this morning in preparation for the rollback. The
structure will remain away from the vehicle in order to maintain
a "ride-out" position until 8 p.m. this evening. The vehicle is
currently in a configuration that would support a rollback if
necessary and the crawler transporter will remain at the Pad's
gate.
At about 12 noon today, workers will begin reconnections
between the launch platform and shuttle. The RSS is currently
scheduled to be moved back around Atlantis at about 8 a.m.
tomorrow. Pad access arms will be positioned later this eveing.
Shuttle managers will continue keeping a close eye on
Hurricane Hugo today. Impacts to the Oct. 12 launch date are
being assessed.
|
| 560.13 | STS-34 Status - September 22 | RENOIR::KLAES | N = R*fgfpneflfifaL | Sat Sep 23 1989 17:48 | 48 |
| From: yee@trident.arc.nasa.gov (Peter E. Yee)
Newsgroups: sci.space
Subject: NASA Headline News for 09/22/89 (Forwarded)
Date: 22 Sep 89 18:57:31 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
Friday, Sept. 22, 1989 Audio report: 202/755-1788
-----------------------------------------------------------------
This is NASA Headline News for Friday, September 22nd:
At the Cape...technicians have moved the Rotating Service
Structure back into place around Atlantis. Today, workers will
continue making connections between the launch pad and the orbiter and
launch platform. Early next week, the payload bay doors will be
opened and a Partial Interface Verification Test will be conducted to
verify those reconnections between the Galileo/Intertial Upper Stage
and the orbiter. Launch date impacts due to preparations for
hurricane Hugo are currently being accessed.
-----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select television. All times are Eastern.
Monday, Sept. 25.....
3:00 A.M. NASA Select TV coverage begins of FltSatCom
launch. Launch window opens at 4:12 A.M.
1:00 P.M. NASA radio programs will be transmitted.
audio only.
Thursday, Sept. 28...
11:30 A.M. NASA Update will be transmitted.
1:00 P.M. Galileo-probe news briefing from Ames
Research Center.
All events and times are subject to change without notice.
-----------------------------------------------------------------
These reports are filed daily Monday through Friday at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA Hdqs.
|
| 560.14 | Launching on time despite Hugo | RENOIR::KLAES | N = R*fgfpneflfifaL | Mon Sep 25 1989 12:10 | 15 |
| From: jordankatz@cdp.UUCP
Newsgroups: sci.space
Subject: NSS Hotline Update 9/24/89
Date: 25 Sep 89 11:16:02 GMT
This is an NSS Space Hotline update.
The latest news from the Kennedy Space Center in Florida suggests
that the Shuttle team will attempt to make up for lost time during the
hurricane Hugo storm threat and may still launch ATLANTIS on Thursday,
October 12. More news on this as it becomes available.
Stay tuned to the NSS Space Hotline for news of the Shuttle
launch, space politics, and more. This is David Brandt reporting.
|
| 560.15 | STS-34 Update - September 25 | RENOIR::KLAES | N = R*fgfpneflfifaL | Mon Sep 25 1989 18:33 | 50 |
| Newsgroups: sci.space
Subject: NASA Headline News for 09/25/89 (Forwarded)
Date: 25 Sep 89 16:25:30 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
NASA Headline News
-----------------------------------------------------------------
Monday, Sept. 25, 1989 Audio: 202/453-1788
-----------------------------------------------------------------
This is NASA Headline News for Monday, September 25:
Processing for the launch of the Atlantis next month continues at
Kennedy Space Center. KSC officials have determined they can still
meet the opening of the launch window on October 12 for the lift off
of the Galileo-carrying shuttle.
In Washington, the Christic Institute, which opposes the launch
of the Galileo spacecraft because it is powered by Radioisotope
Thermoelectric Generators (RTG), told United Press International they
will seek an injunction against the launch by filing suit in district
court in Washington, D.C. about October 3. The anti-nuclear activists
says NASA has underestimated the danger of the launch [and they are
overestimating the dangers. - LK] The protesters also vow to trespass
at KSC and disrupt the launch countdown [Now *that* is dangerous!].
-----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select tv. All times are Eastern.
Thursday, September 28....
11:30 A.M. NASA Update will be transmitted.
1:00 P.M. Galileo probe briefing from Ames Research
Center.
3:30 P.M. Amroc launch carrying MIT/Air Force
experiment from Vandenberg Air Force Base.
Launch window opens at 4:30 P.M.
All events and times are subject to change without notice.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA
Headquarters, Washington, D.C.
|
| 560.16 | | STAR::HUGHES | | Mon Oct 02 1989 16:30 | 22 |
| re a few replies back, asking about launch delays.
The planetary window to send Galileo off towards Venus is (I think)
about a month long, so minor delays can be tolerated. If this window is
missed, the next opportunity will be in 19 months.
The shelf life study indicated that Galileo must launch by 1992 in
order to have sufficient power to perform its primary mission at
Jupiter.
re RTGs
This is the 36th US mission to use RTGs. At least one observer claims
that Lacrosse uses RTGs for power. If true (I've only seen one such
mention), then there has been at least one shuttle launched, RTG
powered spacecraft.
FWIW, it was mentioned in the Ames press conference that the force
required to break the RTG casing is approximately ten times the over
pressure experienced during the Challenger explosion.
gary
|
| 560.17 | STS 34 Press Kit | KAOA04::KLEIN | Nulli Secundus | Tue Oct 03 1989 00:47 | 2057 |
| The following is the complete press kit for the STS34 launch forwarded from
NASA on news.
SPACE SHUTTLE MISSION STS-34 PRESS KIT OCTOBER 1989
PUBLIC AFFAIRS CONTACTS
Sarah Keegan/Barbara Selby
Office of Space Flight
NASA Headquarters, Washington, D.C.
Charles Redmond/Paula Cleggett-Haleim
Office of Space Science and Applications
NASA Headquarters, Washington, D.C.
Jim Ball
Office of Commercial Programs
NASA Headquarters, Washington, D.C.
Lisa Malone
Kennedy Space Center, Fla.
Kyle Herring
Johnson Space Center, Houston, Texas
Jerry Berg
Marshall Space Flight Center, Huntsville, Ala.
Mack Herring
Stennis Space Center, Bay St. Louis, Miss.
Nancy Lovato
Ames-Dryden Flight Research Facility, Edwards, Calif.
Robert J. MacMillin
Jet Propulsion Laboratory, Pasadena, Calif.
Jim Elliott
Goddard Space Flight Center, Greenbelt, Md.
GENERAL RELEASE
RELEASE: 89-151
SHUTTLE ATLANTIS TO DEPLOY GALILEO PROBE TOWARD JUPITER
Space Shuttle mission STS-34 will deploy the Galileo planetary
exploration spacecraft into low-Earth orbit starting Galileo on its journey
to explore Jupiter. Galileo will be the second planetary probe deployed
from the Shuttle this year following Atlantis' successful launch of
Magellan toward Venus exploration in May.
Following deployment about 6 hours after launch, Galileo will be
propelled on a trajectory, known as Venus-Earth-Earth Gravity Assist
(VEEGA) by an Air Force-developed, inertial upper stage (IUS). Galileo's
trajectory will swing around Venus, the sun and Earth before Galileo
makes it's way toward Jupiter.
Flying the VEEGA track, Galileo will arrive at Venus in February 1990.
During the flyby, Galileo will make measurements to determine the
presence of lightning on Venus and take time-lapse photography of Venus'
cloud circulation patterns. Accelerated by Venus' gravity, the spacecraft
will head back to Earth.
Enroute, Galileo will activate onboard remote-sensing equipment to
gather near-infrared data on the composition and characteristics of the
far side of Earth's moon. Galileo also will map the hydrogen distribution
of the Earth's atmosphere.
Acquiring additional energy from the Earth's gravitational forces,
Galileo will travel on a 2-year journey around the sun spending 10 months
inside an asteroid belt. On Oct. 29, 1991, Galileo wlll pass within 600
miles of the asteroid Gaspra.
On the second Earth flyby in December 1992, Galileo will photograph
the north pole of the moon in an effort to determine if ice exists.
Outbound, Galileo will activate the time-lapse photography system to
produce a "movie" of the moon orbiting Earth.
Racing toward Jupiter, Galileo will make a second trek through the
asteroid belt passing within 600 miles of asteroid Ida on Aug. 29, 1993.
Science data gathered from both asteroid encounters will focus on surface
geology and composition.
Five months prior to the Dec. 7, 1995, arrival at Jupiter, Galileo's
atmospheric probe, encased in an oval heat shield, will spin away from the
orbiter at a rate of 5 revolutions per minute (rpm) and follow a ballistic
trajectory aimed at a spot 6 degrees north of Jupiter's equator. The probe
will enter Jupiter's atmosphere at a shallow angle to avoid burning up like
a meteor or ricocheting off the atmosphere back into space.
At approximately Mach 1 speed, the probe's pilot parachute will deploy,
removing the deceleration module aft cover. Deployment of the main
parachute will follow, pulling the descent module out of the aeroshell to
expose the instrument-sensing elements. During the 75-minute descent
into the Jovian atmosphere, the probe will use the orbiter to transmit
data back to Earth. After 75 minutes, the probe will be crushed under the
heavy atmospheric pressure.
The Galileo orbiter will continue its primary mission, orbiting around
Jupiter and four of its satellites, returning science data for the next 22
months.
Galileo's scientific goals include the study of the chemical
composition, state and dynamics of the Jovian atmosphere and satellites,
and the investigation of the structure and physical dynamics of the
powerful Jovian magnetosphere.
Overall responsibility for management of the project, including orbiter
development, resides at NASA's Jet Propulsion Laboratory, Pasadena,
Calif. The NASA Ames Research Center, Mountain View, Calif., manages
the probe system. JPL built the 2,500-lb. spacecraft and Hughes Aircraft
Co. built the 740-lb. probe.
Modifications made to Galileo since flight postponement in 1986
include the addition of sunshields to the base and top of the antenna, new
thermal control surfaces, blankets and heaters. Because of the extended
length of the mission, the electrical circuitry of the thermoelectric
generator has been revised to reduce power demand throughout the
mission to assure adequate power supply for mission completion.
Joining Galileo in the payload bay of Atlantis will be the Shuttle Solar
Backscatter Ultraviolet (SSBUV) instrument. The SSBUV is designed to
provide calibration of backscatter ultraviolet instruments currently being
flown on free-flying satellites. SSBUV's primary objective is to check the
calibration of the ozone sounders on satellites to verify the accuracy of
the data set of atmospheric ozone and solar irradiance data.
The SSBUV is contained in two Get Away Special canisters in the
payload bay and weighs about 1219 lbs . One canister contains the SSBUV
spectrometer and five supporting optical sensors. The second canister
houses data, command and power systems. An interconnecting cable
provides the communication link between the two canisters.
Atlantis also will carry several secondary payloads involving radiation
measurements, polymer morphology, lightning research, microgravity
effects on plants and a student experiment on ice crystal growth in space.
Commander of the 31st Shuttle mission is Donald E. Williams, Captain,
USN. Michael J. McCulley, Commander, USN, is Pilot. Williams flew as
Pilot of mission STS 51-D in April 1985. McCulley will be making his
first Shuttle flight.
Mission Specialists are Shannon W. Lucid, Ph.D.; Franklin R. Chang-Diaz,
Ph.D.; and Ellen S. Baker, M.D. Lucid previously flew as a Mission
Specialist on STS 51-G in June 1985. Chang-Diaz flew as a Mission
Specialist on STS 61-C in January 1986. Baker is making her first Shuttle
flight.
Liftoff of the fifth flight of orbiter Atlantis is scheduled for 1:29 p.m.
EDT on Oct. 12 from Kennedy Space Center, Fla., launch pad 39-B, into a
160-nautical-mile, 34.3-degree orbit. Nominal mission duration is 5
days, 2 hours, 45 minutes. Deorbit is planned on orbit 81, with landing
scheduled for 4:14 p.m. EDT on Oct. 17 at Edwards Air Force Base, Calif.
Liftoff on Oct. 12 could occur during a 10-minute period. The launch
window grows each day reaching a maximum of 47 minutes on Nov. 2. The
window then decreases each day through the remainder of the launch
opportunity which ends Nov. 21. The window is dictated by the need for a
daylight landing opportunity at the trans-Atlantic landing abort sites and
the performance constraint of Galileo's inertial upper stage.
After landing at Edwards AFB, Atlantis will be towed to the NASA
Ames-Dryden Flight Research Facility, hoisted atop the Shuttle Carrier
Aircraft and ferried back to the Kennedy Space Center to begin processing
for its next flight.
GENERAL INFORMATION
NASA Select Television Transmission
NASA Select television is available on Satcom F-2R, Transponder 13,
C-band located at 72 degrees west longitude, frequency 3960.0 MHz,
vertical polarization, audio monaural 6.8 MHz.
The schedule for tv transmissions from the orbiter and for the
change-of-shift briefings from Johnson Space Center, Houston, will be
available during the mission at Kennedy Space Center, Fla.; Marshall Space
Flight Center, Huntsville, Ala.; Johnson Space Center; and NASA
Headquarters, Washington, D.C. The schedule will be updated daily to
reflect changes dictated by mission operations.
TV schedules also may be obtained by calling COMSTOR, 713/483-5817.
COMSTOR is a computer data base service requiring the use of a telephone
modem. Voice updates of the TV schedule may be obtained by dialing
202/755-1788. This service is updated daily at noon EDT.
Special Note to Broadcasters
In the 5 workdays before launch, short sound bites of astronaut interviews
with the STS-34 crew will be available to broadcasters by calling
XXX/YYY-ZZZZ between 8 a.m. and noon EDT.
Status Reports
Status reports on countdown and mission progress, on-orbit activities and
landing operations will be produced by the appropriate NASA news center.
Briefings
An STS-34 mission press briefing schedule will be issued prior to launch.
During the mission, flight control personnel will be on 8-hour shifts.
Change-of-shift briefings by the off-going flight director will occur at
approximately 8-hour intervals.
LAUNCH PREPARATIONS, COUNTDOWN
AND LIFTOFF
Processing activities began on Atlantis for the STS-34 mission on May
16 when Atlantis was towed to Orbiter Processing Facility (OPF) bay 2
after arrival from NASA's Ames-Dryden Flight Research Facility in
California. STS-30 post-flight deconfiguration and inspections were
conducted in the processing hangar.
As planned, the three main engines were removed the last week of May
and taken to the main engine shop in the Vehicle Assembly Building (VAB)
for the replacement of several components including the high pressure
oxidizer turbopumps. The engines were reinstalled the first week of July,
while the ship was in the OPF. Engine 2027 is installed in the number one
position, engine 2030 is in the number two position and engine 2029 is in
the number three position.
The right hand Orbital Maneuvering System (OMS) pod was removed in
mid-June for repairs. A propellant tank needed for Atlantis' pod was
scheduled for delivery too late to support integrated testing. As a result,
Discovery's right pod was installed on Atlantis about 2 weeks later. The
left OMS pod was removed July 9 and reinstalled 2 1/2 weeks later. Both
pods had dynatubes and helium isolation valve repairs in the Hypergolic
Maintenance Facility.
About 34 modifications have been implemented since the STS-30
mission. One significant modification is a cooling system for the
radioisotope thermoelectric generators (RTG). The RTG fuel is plutonium
dioxide which generates heat as a result of its normal decay. The heat is
converted to energy and used to provide electrical power for the Galileo
spacecraft. A mixture of alcohol and water flows in the special cooling
system to lower the RTG case temperature and maintain a desired
temperature to the payload instrumentation in the vicinity of the RTGs.
These cooling lines are mounted on the port side of the orbiter from the
aft compartment to a control panel in bay 4.
Another modification, called "flutter buffet," features special
instrumentation on the vertical tail and right and left outboard elevons.
Ten accelerometers were added to the vertical tail and one on each of the
elevons. These instruments are designed to measure in-flight loads on the
orbiter's structure. Atlantis is the only vehicle that will be equipped with
this instrumentation.
Improved controllers for the water spray boilers and auxiliary power
units were installed. Other improvements were made to the orbiter's
structure and thermal protection system, mechanical systems, propulsion
system and avionics system.
Stacking of solid rocket motor (SRM) segments for flight began with
the left aft booster on Mobile Launcher Platform 1 in the VAB on June 15.
Booster stacking operations were completed by July 22 and the external
tank was mated to the two boosters on July 30.
Flight crew members performed the Crew Equipment Interface Test on
July 29 to become familiar with Atlantis' crew compartment, vehicle
configuration and equipment associated with the mission.
The Galileo probe arrived at the Spacecraft Assembly and
Encapsulation Facility (SAEF) 2 on April 17 and the spacecraft arrived on
May 16. While at SAEF-2, the spacecraft and probe were joined and tested
together to verify critical connections. Galileo was delivered to the
Vertical Processing Facility (VPF) on Aug. 1. The Inertial Upper Stage
(IUS) was delivered to the VPF on July 30. The Galileo/IUS were joined
together on Aug. 3 and all integrated testing was performed during the
second week of August.
The Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment,
contained in two Get Away Special (GAS) canisters, was mounted on a
special GAS beam in Atlantis' payload bay on July 24. Interface
verification tests were performed the next day.
Atlantis was transferred from the OPF to the VAB on Aug. 21, where it
was mated to the external tank and SRBs. A Shuttle Interface Test was
conducted in the VAB to check the mechanical and electrical connections
between the various elements of the Shuttle vehicle and onboard flight
systems.
The assembled Space Shuttle vehicle was rolled out of the VAB aboard
its mobile launcher platform for the 4.2 mile trip to Launch Pad 39-B on
Aug. 29. Galileo and its IUS upper stage were transferred from the VPF to
Launch Pad 39-B on Aug. 25. The payload was installed in Atlantis'
payload bay on Aug. 30.
The payload interface verification test was planned for Sept. 7 to
verify connections between the Shuttle and the payload. An end-to-end
test was planned for Sept. 8 to verify communications between the
spacecraft and ground controllers. Testing of the IUS was planned about 2
weeks prior to launch in parallel with Shuttle launch preparations.
A Countdown Demonstration Test, a dress rehearsal for the STS-34
flight crew and KSC launch team, is designed as a practice countdown for
the launch. At press time, it was planned for Sept. 14 and 15.
One of the unique STS-34 processing milestones planned was a
simulation exercise for the installation of the RTGs. Simulated RTGs
were to be used in the 2-day event scheduled within the first week after
Atlantis arrives at the launch pad. The test is designed to give workers
experience for the installation of the RTGs, a first in the Shuttle program.
In addition, access requirements will be identified and procedures will be
verified.
Another test scheduled at the pad is installation of the flight RTGs and
an associated test and checkout of the RTG cooling system planned for the
third week of September. This test will verify the total RTG cooling
system and connections. The RTGs will be removed at the completion of
the 3-day cooling system test and returned to the RTG facility. The two
flight RTGs will be reinstalled on the spacecraft 6 days before launch.
Launch preparations scheduled the last 2 weeks prior to launch countdown
include final vehicle ordnance activities, such as power-on stray-voltage
checks and resistance checks of firing circuits; loading the fuel cell
storage tanks; pressurizing the hypergolic propellant tanks aboard the
vehicle; final payload closeouts; and a final functional check of the range
safety and SRB ignition, safe and arm devices.
The launch countdown is scheduled to pick up at the T-minus 43-hour
mark, leading up to the STS-34 launch. Atlantis' fifth launch will be
conducted by a joint NASA/industry team from Firing Room 1 in the Launch
Control Center.
MAJOR COUNTDOWN MILESTONES
Countdown Event
T-43 Hours Power up Space Shuttle vehicle.
T-34 Hours Begin orbiter and ground support
equipment closeouts for launch.
T-30 Hours Activate orbiter's navigation aids.
T-27 Hours (holding) Enter first built-in hold for 8 hours.
T-27 Hours (counting) Begin preparations for loading fuel
cell storage tanks with liquid oxygen
and liquid hydrogen reactants.
T-25 Hours Load orbiter's fuel cell tanks with
liquid oxygen.
T-22 Hours, 30 minutes Load orbiter's fuel cell tanks with
liquid hydrogen.
T-22 Hours Perform interface check between
Houston Mission Control and Merritt
Island Launch Area (MILA) tracking
station.
T-20 Hours Activate and warm up inertial
measurement units (IMU).
T-19 Hours (holding) Enter 8-hour built-in hold. Activate
orbiter communications system.
T-19 hours (counting) Resume countdown. Continue preparations to load
external tank, orbiter closeouts and preparations
to move the Rotating Service Structure (RSS).
T-11 Hours (holding) Start 14-hour, 40 minute built-in hold
orbiter flight and middecks.
T-11 Hours (counting) Retract RSS from vehicle to launch
position.
T-9 Hours Activate orbiter's fuel cells.
T-8 Hours Configure Mission Control communications
for launch. Start clearing
blast danger area.
T-6 Hours, 30 minutes Perform Eastern Test Range open
loop command test.
T-6 Hours (holding) Enter 1-hour built-in hold. Receive
management "go" for tanking.
T-6 Hours (counting) Start external tank chilldown and
propellant loading.
T-5 Hours Start IMU pre-flight calibration.
T-4 Hours Perform MILA antenna alignment.
T-3 Hours (holding) 2-hour built-in hold begins. Loading
of external tank is complete and in a
stable replenish mode. Ice team
goes to pad for inspections. Closeout
crew goes to white room to begin
preparing orbiter's cabin for flight
crew's entry. Wake flight crew
(launch minus 4 hours, 55 minutes).
T-3 Hours (counting) Resume countdown.
T-2 Hours, 55 minutes Flight crew departs O&C Building for
Launch Pad 39-B (Launch minus 3
hours,15 minutes).
T-2 Hours, 30 minutes Crew enters orbiter vehicle (Launch
minus 2 Hours, 50 minutes).
T-60 minutes Start pre-flight alignment of IMUs.
T-20 minutes (holding) 10-minute built-in hold begins.
T-20 minutes(counting) Configure orbiter computers for
launch.
T-10 minutes White room closeout crew cleared
through launch danger are a
roadblocks.
T-9 minutes (holding) 40-minute built-in hold begins.
Perform status check and receive
Launch Director and Mission
Management Team "go."
T-9 minutes (counting) Start ground launch sequencer.
T-7 minutes, 30 seconds Retract orbiter access arm.
T-5 minutes Pilot starts auxiliary power units. Arm
range safety, solid rocket booster
(SRB) ignition systems.
T-3 minutes, 30 seconds Orbiter goes on internal power.
T-2 minutes, 55 seconds Pressurize liquid oxygen tank for
flight and retract gaseous oxygen
vent hood.
T-1 minute, 57 seconds Pressurize liquid hydrogen tank.
T-31 seconds "Go" from ground computer for
orbiter computers to start the
automatic launch sequence.
T-28 seconds Start SRB hydraulic power units.
T-21 seconds Start SRB gimbal profile test.
T-6.6 seconds Main engine start.
T-3 seconds Main engines at 90 percent thrust.
T-0 SRB ignition, holddown post
release and liftoff.
T+7 seconds Shuttle clears launch tower and
control switches to JSC.
Note: This countdown timeline may be adjusted in real time as necessary.
TRAJECTORY SEQUENCE OF EVENTS
__________________________________________________________
RELATIVE
EVENT MET VELOCITY MACH ALTITUDE
(d:h:m:s) (fps) (ft.)
__________________________________________________________
Launch 00/00:00:00
Begin Roll Maneuver 00/00:00:09 165 .15 627
End Roll Maneuver 00/00:00:17 374 .33 2,898
SSME Throttle Down to 65% 00/00:00:34 833 .75 11,854
Max. Dyn. Pressure (Max Q)00/00:00:52 1,260 1.2 28,037
SSME Throttle Up to 104% 00/00:01:01 1,499 1.49 38,681
SRB Staging 00/00:02:04 4,316 3.91 153,873
Negative Return 00/00:03:54 6,975 7.48 317,096
Main Engine Cutoff (MECO) 00/00:08:27 24,580 22.41 366,474
Zero Thrust 00/00:08:33 24,596 22.17 368,460
ET Separation 00/00:08:45
OMS 2 Burn 00/00:39:48
Galileo/IUS Deploy (orb 5)00/06:21:36
Deorbit Burn (orbit 81) 05/01:45:00
Landing (orbit 82) 05/02:45:00
Apogee, Perigee at MECO: 157 x 39 nm
Apogee, Perigee post-OMS 2: 161 x 161 nm
Apogee, Perigee post deploy: 177 x 161 nm
SPACE SHUTTLE ABORT MODES
Space Shuttle launch abort philosophy aims toward safe and intact recovery
of the flight crew, orbiter and its payload. Abort modes include:
* Abort-To-Orbit (ATO) -- Partial loss of main engine thrust late enough to
permit reaching a minimal 105-nautical mile orbit with orbital
maneuvering system engines.
* Abort-Once-Around (AOA) -- Earlier main engine shutdown with the
capability to allow one orbit around before landing at Edwards Air Force
Base, Calif.; White Sands Space Harbor (Northrup Strip), N.M.; or the Shuttle
Landing Facility (SLF) at Kennedy Space Center (KSC), Fla.
* Trans-Atlantic Abort Landing (TAL) -- Loss of two main engines midway
through powered flight would force a landing at Ben Guerir, Morocco; Moron,
Spain; or Banjul, The Gambia.
* Return-To-Launch-Site (RTLS) -- Early shutdown of one or more engines
and without enough energy to reach Ben Guerir, would result in a pitch
around and thrust back toward KSC until within gliding distance of the SLF.
STS-34 contingency landing sites are Edwards AFB, White Sands, KSC, Ben
Guerir, Moron and Banjul.
SUMMARY OF MAJOR ACTIVITIES
Day One
Ascent
Post-insertion checkout
Pre-deploy checkout
Galileo/Inertial Upper Stage (IUS) deploy
Detailed Secondary Objective (DSO)
Polymer Morphology (PM)
Sensor Technology Experiment (STEX) activation
Day Two
Galileo/IUS backup deploy opportunity
DSO
IMAX
PM
Shuttle Solar Backscatter Ultraviolet (SSBUV) activation
Shuttle Student Involvement Program (SSIP)
Day Three
DSO
IMAX
Mesoscale Lightning Experiment (MLE)
PM
Day Four
DSO
IMAX
MLE
PM
SSBUV deactivation
Day Five
DTO/DSO
GHCD operations
PM
STEX deactivation
Flight control systems (FCS) checkout
Cabin stow
Landing preparations
Day Six
PM stow
Deorbit preparation
Deorbit burn
Landing at Edwards AFB
LANDING AND POST LANDING OPERATIONS
Kennedy Space Center, Fla., is responsible for ground operations of the
orbiter once it has rolled to a stop on the runway at Edwards Air Force
Base, Calif. Those operations include preparing the Shuttle for the return
trip to Kennedy.
After landing, the flight crew aboard Atlantis begins "safing" vehicle
systems. Immediately after wheel stop, specially garbed technicians will
first determine that any residual hazardous vapors are below significant
levels for other safing operations to proceed.
A mobile white room is moved into place around the crew hatch once it
is verified that there are no concentrations of toxic gases around the
forward part of the vehicle. The flight crew is expected to leave Atlantis
about 45 to 50 minutes after landing. As the crew exits, technicians enter
the orbiter to complete the vehicle safing activity.
Once the initial aft safety assessment is made, access vehicles are
positioned around the rear of the orbiter so that lines from the ground
purge and cooling vehicles can be connected to the umbilical panels on the
aft end of Atlantis.
Freon line connections are completed and coolant begins circulating
through the umbilicials to aid in heat rejection and protect the orbiter's
electronic equipment. Other lines provide cooled, humidified air to the
payload bay and other cavities to remove any residual fumes and provide a
safe environment inside Atlantis.
A tow tractor will be connected to Atlantis and the vehicle will be
pulled off the runway at Edwards and positioned inside the Mate/Demate
Device (MDD) at nearby Ames-Dryden Flight Research Facility. After the
Shuttle has been jacked and leveled, residual fuel cell cryogenics are
drained and unused pyrotechnic devices are disconnected prior to returning
the orbiter to Kennedy.
The aerodynamic tail cone is installed over the three main engines,
and the orbiter is bolted on top of the 747 Shuttle Carrier Aircraft for the
ferry flight back to Florida. Pending completion of planned work and
favorable weather conditions, the 747 would depart California about 6 days
after landing for the cross-country ferry flight back to Florida. A refueling
stop is necessary to complete the journey.
Once back at Kennedy, Atlantis will be pulled inside the hangar-like
facility for post-flight inspections and in-flight anomaly troubleshooting.
These operations are conducted in parallel with the start of routine
systems reverification to prepare Atlantis for its next mission.
GALILEO
Galileo is a NASA spacecraft mission to Jupiter to study the planet's
atmosphere, satellites and surrounding magnetosphere. It was named for
the Italian renaissance scientist who discovered Jupiter's major moons by
using the first astronomical telescope.
This mission will be the first to make direct measurements from an
instrumented probe within Jupiter's atmosphere and the first to conduct
long-term observations of the planet and its magnetosphere and satellites
from orbit around Jupiter. It will be the first orbiter and atmospheric
probe for any of the outer planets. On the way to Jupiter, Galileo also will
observe Venus, the Earth-moon system, one or two asteroids and various
phenomena in interplanetary space.
Galileo will be boosted into low-Earth orbit by the Shuttle Atlantis and
then boosted out of Earth orbit by a solid rocket Inertial Upper Stage. The
spacecraft will fly past Venus and twice by the Earth, using gravity assists
from the planets to pick up enough speed to reach Jupiter. Travel time from
launch to Jupiter is a little more than 6 years.
In December 1995, the Galileo atmospheric probe will conduct a brief,
direct examination of Jupiter's atmosphere, while the larger part of the
craft, the orbiter, begins a 22-month, 10-orbit tour of major satellites and
the magnetosphere, including long-term observations of Jupiter throughout
this phase.
The 2-ton Galileo orbiter spacecraft carries 9 scientific instruments.
There are another six experiments on the 750-pound probe. The spacecraft
radio link to Earth serves as an additional instrument for scientific
measurements. The probe's scientific data will be relayed to Earth by the
orbiter during the 75-minute period while the probe is descending into
Jupiter's atmosphere. Galileo will communicate with its controllers and
scientists through NASAUs Deep Space Network, using tracking stations in
California, Spain and Australia.
GALILEO MISSION EVENTS
Launch Window (Atlantis and IUS) Oct. 12 to Nov. 21, 1989
(Note: for both asteroids, closes in mid-October)
Venus flyby ( 9,300 mi) *Feb. 9, 1990
Venus data playback Oct. 1990
Earth 1 flyby ( about 600 mi) *Dec. 8, 1990
Asteroid Gaspra flyby (600 mi) *Oct. 29, 1991
Earth 2 flyby (200 mi) *Dec. 8, 1992
Asteroid Ida flyby (600 mi) *Aug. 28, 1993
Probe release July 1995
Jupiter arrival Dec. 7, 1995
(includes Io flyby, probe entry and relay, Jupiter orbit insertion)
Orbital tour of Galilean satellites Dec '95-Oct '97
*Exact dates may vary according to actual launch date
EARTH TO JUPITER
Galileo will make three planetary encounters in the course of its
gravity-assisted flight to Jupiter. These provide opportunities for
scientific observation and measurement of Venus and the Earth-moon
system. The mission also has a chance to fly close to one or two asteroids,
bodies which have never been observed close up, and obtain data on other
phenomena of interplanetary space.
Scientists are currently studying how to use the Galileo scientific
instruments and the limited ability to collect, store and transmit data
during the early phase of flight to make the best use of these opportunities.
Instruments designed to observe Jupiter's atmosphere from afar can
improve our knowledge of the atmosphere of Venus and sensors designed for
the study of Jupiter's moons can add to our information about our own moon.
VENUS
The Galileo spacecraft will approach Venus early in 1990 from the night
side and pass across the sunlit hemisphere, allowing observation of the
clouds and atmosphere. Both infrared and ultraviolet spectral observations
are planned, as well as several camera images and other remote
measurements. The search for deep cloud patterns and for lightning storms
will be limited by the fact that all the Venus data must be tape-recorded on
the spacecraft for playback 8 months later.
The spacecraft was originally designed to operate between Earth and
Jupiter, where sunlight is 25 times weaker than at Earth and temperatures
are much lower. The VEEGA mission will expose the spacecraft to a hotter
environment from Earth to Venus and back. Spacecraft engineers devised a
set of sunshades to protect the craft. For this system to work, the front
end of the spacecraft must be aimed precisely at the Sun, with the main
antenna furled for protection from the Sun's rays until after the first Earth
flyby in December 1990. This precludes the use of the Galileo high-gain
antenna and therefore, scientists must wait until the spacecraft is close to
Earth to receive the recorded Venus data, transmitted through a low-gain
antenna.
FIRST EARTH PASS
Approaching Earth for the first time about 14 months after launch, the
Galileo spacecraft will observe, from a distance, the nightside of Earth and
parts of both the sunlit and unlit sides of the moon. After passing Earth,
Galileo will observe Earth's sunlit side. At this short range, scientific data
are transmitted at the high rate using only the spacecraft's low-gain
antennas. The high-gain antenna is to be unfurled like an umbrella, and its
high-power transmitter turned on and checked out, about 5 months after the
first Earth encounter.
FIRST ASTEROID
Nine months after the Earth passage and still in an elliptical solar orbit,
Galileo will enter the asteroid belt, and two months later, will have its
first asteroid encounter. Gaspra is believed to be a fairly representative
main-belt asteroid, about 10 miles across and probably similar in
composition to stony meteorites.
The spacecraft will pass within about 600 miles at a relative speed of
about 18,000 miles per hour. It will collect several pictures of Gaspra and
make spectral measurements to indicate its composition and physical
properties.
SECOND EARTH PASS
Thirteen months after the Gaspra encounter, the spacecraft will have
completed its 2-year elliptical orbit around the Sun and will arrive back at
Earth. It will need a much larger ellipse (with a 6-year period) to reach as
far as Jupiter. The second flyby of Earth will pump the orbit up to that
size, acting as a natural apogee kick motor for the Galileo spacecraft.
Passing about 185 miles above the surface, near the altitude at which it
had been deployed from the Space Shuttle almost three years earlier,
Galileo will use Earth's gravitation to change the spacecraft's flight
direction and pick up about 8,000 miles per hour in speed.
Each gravity-assist flyby requires about three rocket-thrusting
sessions, using Galileo's onboard retropropulsion module, to fine-tune the
flight path. The asteroid encounters require similar maneuvers to obtain
the best observing conditions.
Passing the Earth for the last time, the spacecraft's scientific
equipment will make thorough observations of the planet, both for
comparison with Venus and Jupiter and to aid in Earth studies. If all goes
well, there is a good chance that Galileo will enable scientists to record
the motion of the moon about the Earth while the Earth itself rotates.
SECOND ASTEROID
Nine months after the final Earth flyby, Galileo may have a second
asteroid-observing opportunity. Ida is about 20 miles across. Like Gaspra,
Ida is believed to represent the majority of main-belt asteroids in
composition, though there are believed to be differences between the two.
Relative velocity for this flyby will be nearly 28,000 miles per hour, with a
planned closest approach of about 600 miles.
APPROACHING JUPITER
Some 2 years after leaving Earth for the third time and 5 months before
reaching Jupiter, Galileo's probe must separate from the orbiter. The
spacecraft turns to aim the probe precisely for its entry point in the
Jupiter atmosphere, spins up to 10 revolutions per minute and releases the
spin-stabilized probe. Then the Galileo orbiter maneuvers again to aim for
its own Jupiter encounter and resumes its scientific measurements of the
interplanetary environment underway since the launch more than 5 years
before.
While the probe is still approaching Jupiter, the orbiter will have its
first two satellite encounters. After passing within 20,000 miles of
Europa, it will fly about 600 miles above Io's volcano-torn surface, twenty
times closer than the closest flyby altitude of Voyager in 1979.
AT JUPITER
The Probe at Jupiter
The probe mission has four phases: launch, cruise, coast and
entry-descent. During launch and cruise, the probe will be carried by the
orbiter and serviced by a common umbilical. The probe will be dormant
during cruise except for annual checkouts of spacecraft systems and
instruments. During this period, the orbiter will provide the probe with
electric power, commands, data transmission and some thermal control.
Six hours before entering the atmosphere, the probe will be shooting
through space at about 40,000 mph. At this time, its command unit signals
"wake up" and instruments begin collecting data on lightning, radio
emissions and energetic particles.
A few hours later, the probe will slam into Jupiter's atmosphere at
115,000 mph, fast enough to jet from Los Angeles to New York in 90
seconds. Deceleration to about Mach 1 -- the speed of sound -- should take
just a few minutes. At maximum deceleration as the craft slows from
115,000 mph to 100 mph, it will be hurtling against a force 350 times
Earth's gravity. The incandescent shock wave ahead of the probe will be as
bright as the sun and reach searing temperatures of up to 28,000 degrees
Fahrenheit. After the aerodynamic braking has slowed the probe, it will
drop its heat shields and deploy its parachute. This will allow the probe to
float down about 125 miles through the clouds, passing from a pressure of
1/10th that on Earth's surface to about 25 Earth atmospheres.
About 4 minutes after probe entry into JupiterUs atmosphere, a pilot
chute deploys and explosive nuts shoot off the top section of the probe's
protective shell. As the cover whips away, it pulls out and opens the main
parachute attached to the inner capsule. What remains of the probe's outer
shell, with its massive heat shield, falls away as the parachute slows the
instrument module.
From there on, suspended from the main parachute, the probe's capsule
with its activated instruments floats downward toward the bright clouds
below.
The probe will pass through the white cirrus clouds of ammonia crystals
- the highest cloud deck. Beneath this ammonia layer probably lie
reddish-brown clouds of ammonium hydrosulfides. Once past this layer, the
probe is expected to reach thick water clouds. This lowest cloud layer may
act as a buffer between the uniformly mixed regions below and the
turbulent swirl of gases above.
Jupiter's atmosphere is primarily hydrogen and helium. For most of its
descent through Jupiter's three main cloud layers, the probe will be
immersed in gases at or below room temperature. However, it may
encounter hurricane winds up to 200 mph and lightning and heavy rain at the
base of the water clouds believed to exist on the planet. Eventually, the
probe will sink below these clouds, where rising pressure and temperature
will destroy it. The probe's active life in Jupiter's atmosphere is expected
to be about 75 minutes in length. The probe batteries are not expected to
last beyond this point, and the relaying orbiter will move out of reach.
To understand this huge gas planet, scientists must find out about its
chemical components and the dynamics of its atmosphere. So far,
scientific data are limited to a two-dimensional view (pictures of the
planet's cloud tops) of a three-dimensional process (Jupiter's weather). But
to explore such phenomena as the planet's incredible coloring, the Great Red
Spot and the swirling shapes and high-speed motion of its topmost clouds,
scientists must penetrate Jupiter's visible surface and investigate the
atmosphere concealed in the deep-lying layers below.
A set of six scientific instruments on the probe will measure, among
other things, the radiation field near Jupiter, the temperature, pressure,
density and composition of the planet's atmosphere from its first faint
outer traces to the hot, murky hydrogen atmosphere 100 miles below the
cloud tops. All of the information will be gathered during the probe's
descent on an 8-foot parachute. Probe data will be sent to the Galileo
Orbiter 133,000 miles overhead then relayed across the half billion miles
to Deep Space Network stations on Earth.
To return its science, the probe relay radio aboard the orbiter must
automatically acquire the probe signal below within 50 seconds, with a
success probability of 99.5 percent. It must reacquire the signal
immediately should it become lost.
To survive the heat and pressure of entry, the probe spacecraft is
composed of two separate units: an inner capsule containing the scientific
instruments, encased in a virtually impenetrable outer shell. The probe
weighs 750 pounds. The outer shell is almost all heat shield material.
The Orbiter at Jupiter
After releasing the probe, the orbiter will use its main engine to go into
orbit around Jupiter. This orbit, the first of 10 planned, will have a period
of about 8 months. A close flyby of Ganymede in July 1996 will shorten the
orbit, and each time the Galileo orbiter returns to the inner zone of
satellites, it will make a gravity-assist close pass over one or another of
the satellites, changing Galileo's orbit while making close observations.
These satellite encounters will be at altitudes as close as 125 miles above
their surfaces. Throughout the 22-month orbital phase, Galileo will
continue observing the planet and the satellites and continue gathering data
on the magnetospheric environment.
SCIENTIFIC ACTIVITIES
Galileo's scientific experiments will be carried out by more than 100
scientists from six nations. Except for the radio science investigation,
these are supported by dedicated instruments on the Galileo orbiter and
probe. NASA has appointed 15 interdisciplinary scientists whose studies
include data from more than one Galileo instrument.
The instruments aboard the probe will measure the temperatures and
pressure of Jupiter's atmosphere at varying altitudes and determine its
chemical composition including major and minor constituents (such as
hydrogen, helium, ammonia, methane, and water) and the ratio of hydrogen
to helium. Jupiter is thought to have a bulk composition similar to that of
the primitive solar nebula from which it was formed. Precise
determination of the ratio of hydrogen to helium would provide an
important factual check of the Big Bang theory of the genesis of the
universe.
Other probe experiments will determine the location and structure of
Jupiter's clouds, the existence and nature of its lightning, and the amount
of heat radiating from the planet compared to the heat absorbed from
sunlight.
In addition, measurements will be made of Jupiter's numerous radio
emissions and of the high-energy particles trapped in the planet's
innermost magnetic field. These measurements for Galileo will be made
within a distance of 26,000 miles from Jupiter's cloud tops, far closer than
the previous closest approach to Jupiter by Pioneer 11. The probe also will
determine vertical wind shears using Doppler radio measurements made of
probe motions from the radio receiver aboard the orbiter.
Jupiter appears to radiate about twice as much energy as it receives
from the sun and the resulting convection currents from Jupiter's internal
heat source towards its cooler polar regions could explain some of the
planet's unusual weather patterns.
Jupiter is over 11 times the diameter of Earth and spins about two and
one-half times faster -- a jovian day is only 10 hours long. A point on the
equator of Jupiter's visible surface races along at 28,000 mph. This rapid
spin may account for many of the bizarre circulation patterns observed on
the planet.
Spacecraft Scientific Activities
The Galileo mission and systems were designed to investigate three
broad aspects of the Jupiter system: the planet's atmosphere, the satellites
and the magnetosphere. The spacecraft is in three segments to focus on
these areas: the atmospheric probe; a non-spinning section of the orbiter
carrying cameras and other remote sensors; and the spinning main section
of the orbiter spacecraft which includes the propulsion module, the
communications antennas, main computers and most support systems as
well as the fields and particles instruments, which sense and measure the
environment directly as the spacecraft flies through it.
Probe Scientific Activities
The probe will enter the atmosphere about 6 degrees north of the
equator. The probe weighs just under 750 pounds and includes a
deceleration module to slow and protect the descent module, which carries
out the scientific mission.
The deceleration module consists of an aeroshell and an aft cover
designed to block the heat generated by slowing from the probe's arrival
speed of about 115,000 miles per hour to subsonic speed in less than 2
minutes. After the covers are released, the descent module deploys its
8-foot parachute and its instruments, the control and data system, and the
radio-relay transmitter go to work.
Operating at 128 bits per second, the dual L-band transmitters send
nearly identical streams of scientific data to the orbiter. The probe's relay
radio aboard the orbiter will have two redundant receivers that process
probe science data, plus radio science and engineering data for
transmission to the orbiter communications system. Minimum received
signal strength is 31 dBm. The receivers also measure signal strength and
Doppler shift as part of the experiments for measuring wind speeds and
atmospheric absorption of radio signals.
Probe electronics are powered by long-life, high-discharge-rate 34-volt
lithium batteries, which remain dormant for more than 5 years during the
journey to Jupiter. The batteries have an estimated capacity of about 18
amp-hours on arrival at Jupiter.
Orbiter Scientific Activities
The orbiter, in addition to delivering the probe to Jupiter and relaying
probe data to Earth, will support all the scientific investigations of Venus,
the Earth and moon, asteroids and the interplanetary medium, Jupiter's
satellites and magnetosphere, and observation of the giant planet itself.
The orbiter weighs about 5,200 pounds including about 2,400 pounds of
rocket propellant to be expended in some 30 relatively small maneuvers
during the long gravity-assisted flight to Jupiter, the large thrust
maneuver which puts the craft into its Jupiter orbit, and the 30 or so trim
maneuvers planned for the satellite tour phase.
The retropropulsion module consists of 12 10-newton thrusters, a single
400-newton engine, and the fuel, oxidizer, and pressurizing-gas tanks,
tubing, valves and control equipment. (A thrust of 10 newtons would
support a weight of about 2.2 pounds at Earth's surface). The propulsion
system was developed and built by Messerschmitt-Bolkow-Blohm and
provided by the Federal Republic of Germany.
The orbiter's maximum communications rate is 134 kilobits per second
(the equivalent of about one black-and-white image per minute); there are
other data rates, down to 10 bits per second, for transmitting engineering
data under poor conditions. The spacecraft transmitters operate at S-band
and X-band (2295 and 8415 megahertz) frequencies between Earth and on
L-band between the probe.
The high-gain antenna is a 16-foot umbrella-like reflector unfurled
after the first Earth flyby. Two low-gain antennas (one pointed forward
and one aft, both mounted on the spinning section) are provided to support
communications during the Earth-Venus-Earth leg of the flight and
whenever the main antenna is not deployed and pointed at Earth. The despun
section of the orbiter carries a radio relay antenna for receiving the probe's
data transmissions.
Electrical power is provided to Galileo's equipment by two radioisotope
thermoelectric generators. Heat produced by natural radioactive decay of
plutonium 238 dioxide is converted to approximately 500 watts of
electricity (570 watts at launch, 480 at the end of the mission) to operate
the orbiter equipment for its 8-year active period. This is the same type of
power source used by the Voyager and Pioneer Jupiter spacecraft in their
long outer-planet missions, by the Viking lander spacecraft on Mars and the
lunar scientific packages left on the Moon.
Most spacecraft are stabilized in flight either by spinning around a
major axis or by maintaining a fixed orientation in space, referenced to the
sun and another star. Galileo represents a hybrid of these techniques, with
a spinning section rotating ordinarily at 3 rpm and a "despun" section which
is counter-rotated to provide a fixed orientation for cameras and other
remote sensors.
Instruments that measure fields and particles, together with the main
antenna, the power supply, the propulsion module, most of the computers
and control electronics, are mounted on the spinning section. The
instruments include magnetometer sensors mounted on a 36-foot boom to
escape interference from the spacecraft; a plasma instrument detecting
low-energy charged particles and a plasma-wave detector to study waves
generated in planetary magnetospheres and by lightning discharges; a
high-energy particle detector; and a detector of cosmic and Jovian dust.
The despun section carries instruments and other equipment whose
operation depends on a fixed orientation in space. The instruments include
the camera system; the near-infrared mapping spectrometer to make
multispectral images for atmosphere and surface chemical analysis; the
ultraviolet spectrometer to study gases and ionized gases; and the
photopolarimeter radiometer to measure radiant and reflected energy. The
camera system is expected to obtain images of Jupiter's satellites at
resolutions from 20 to 1,000 times better than Voyager's best.
This section also carries a dish antenna to track the probe in Jupiter's
atmosphere and pick up its signals for relay to Earth. The probe is carried
on the despun section, and before it is released, the whole spacecraft is
spun up briefly to 10 rpm in order to spin-stabilize the probe.
The Galileo spacecraft will carry out its complex operations, including
maneuvers, scientific observations and communications, in response to
stored sequences which are interpreted and executed by various on-board
computers. These sequences are sent up to the orbiter periodically through
the Deep Space Network in the form of command loads.
GROUND SYSTEMS
Galileo communicates with Earth via NASA's Deep Space Network (DSN),
which has a complex of large antennas with receivers and transmitters
located in the California desert, another in Australia and a third in Spain,
linked to a network control center at NASAUs Jet Propulsion Laboratory in
Pasadena, Calif. The spacecraft receives commands, sends science and
engineering data, and is tracked by Doppler and ranging measurements
through this network.
At JPL, about 275 scientists, engineers and technicians, will be supporting
the mission at launch, increasing to nearly 400 for Jupiter operations
including support from the German retropropulsion team at their control
center in the FGR. Their responsibilities include spacecraft command,
interpreting engineering and scientific data from Galileo to understand its
performance, and analyzing navigation data from the DSN. The controllers
use a set of complex computer programs to help them control the
spacecraft and interpret the data.
Because the time delay in radio signals from Earth to Jupiter and back is
more than an hour, the Galileo spacecraft was designed to operate from
programs sent to it in advance and stored in spacecraft memory. A single
master sequence program can cover 4 weeks of quiet operations between
planetary and satellite encounters. During busy Jupiter operations, one
program covers only a few days. Actual spacecraft tasks are carried out by
several subsystems and scientific instruments, many of which work from
their own computers controlled by the main sequence.
Designing these sequences is a complex process balancing the desire to
make certain scientific observations with the need to safeguard the
spacecraft and mission. The sequence design process itself is supported by
software programs, for example, which display to the scientist maps of the
instrument coverage on the surface of an approaching satellite for a given
spacecraft orientation and trajectory. Notwithstanding these aids, a
typical 3-day satellite encounter may take efforts spread over many
months to design, check and recheck. The controllers also use software
designed to check the command sequence further against flight rules and
constraints.
The spacecraft regularly reports its status and health through an
extensive set of engineering measurements. Interpreting these data into
trends and averting or working around equipment failures is a major task
for the mission operations team. Conclusions from this activity become an
important input, along with scientific plans, to the sequence design
process. This too is supported by computer programs written and used in
the mission support area.
Navigation is the process of estimating, from radio range and Doppler
measurements, the position and velocity of the spacecraft to predict its
flight path and design course-correcting maneuvers. These calculations
must be done with computer support. The Galileo mission, with its complex
gravity-assist flight to Jupiter and 10 gravity-assist satellite encounters
in the Jovian system, is extremely dependent on consistently accurate
navigation.
In addition to the programs that directly operate the spacecraft and are
periodically transmitted to it, the mission operations team uses software
amounting to 650,000 lines of programming code in the sequence design
process; 1,615,000 lines in the telemetry interpretation; and 550,000 lines
of code in navigation. These must all be written, checked, tested, used in
mission simulations and, in many cases, revised before the mission can
begin.
Science investigators are located at JPL or other university laboratories
and linked by computers. From any of these locations, the scientists can be
involved in developing the sequences affecting their experiments and, in
some cases, in helping to change preplanned sequences to follow up on
unexpected discoveries with second looks and confirming observations.
JUPITER'S SYSTEM
Jupiter is the largest and fastest-spinning planet in the solar system.
Its radius is more than 11 times Earth's, and its mass is 318 times that of
our planet. Named for the chief of the Roman gods, Jupiter contains more
mass than all the other planets combined. It is made mostly of light
elements, principally hydrogen and helium. Its atmosphere and clouds are
deep and dense, and a significant amount of energy is emitted from its
interior.
The earliest Earth-based telescopic observations showed bands and
spots in Jupiter's atmosphere. One storm system, the Red Spot, has been
seen to persist over three centuries.
Atmospheric forms and dynamics were observed in increasing detail
with the Pioneer and Voyager flyby spacecraft, and Earth-based infrared
astronomers have recently studied the nature and vertical dynamics of
deeper clouds.
Sixteen satellites are known. The four largest, discovered by the Italian
scientist Galileo Galilei in 1610, are the size of small planets. The
innermost of these, Io, has active sulfurous volcanoes, discovered by
Voyager 1 and further observed by Voyager 2 and Earth-based infrared
astronomy. Io and Europa are about the size and density of Earth's moon (3
to 4 times the density of water) and probably rocky inside. Ganymede and
Callisto, further out from Jupiter, are the size of Mercury but less than
twice as dense as water. Their cratered surfaces look icy in Voyager
images, and they may be composed partly of ice or water.
Of the other satellites, eight (probably captured asteroids) orbit
irregularly far from the planet, and four (three discovered by the Voyager
mission in 1979) are close to the planet. Voyager also discovered a thin
ring system at Jupiter in 1979.
Jupiter has the strongest planetary magnetic field known. The resulting
magnetosphere is a huge teardrop-shaped, plasma-filled cavity in the solar
wind pointing away from the sun. JupiterUs magnetosphere is the largest
single entity in our solar system, measuring more than 14 times the
diameter of the sun. The inner part of the magnetic field is doughnut-
shaped, but farther out it flattens into a disk. The magnetic poles are
offset and tilted relative to Jupiter's axis of rotation, so the field appears
to wobble with Jupiter's rotation (just under 10 hours), sweeping up and
down across the inner satellites and making waves throughout the
magnetosphere.
WHY JUPITER INVESTIGATIONS ARE IMPORTANT
With a thin skin of turbulent winds and brilliant, swift-moving clouds,
the huge sphere of Jupiter is a vast sea of liquid hydrogen and helium.
Jupiter's composition (about 88 percent hydrogen and 11 percent helium
with small amounts of methane, ammonia and water) is thought to resemble
the makeup of the solar nebula, the cloud of gas and dust from which the
sun and planets formed. Scientists believe Jupiter holds important clues to
conditions in the early solar system and the process of planet formation.
Jupiter may also provide insights into the formation of the universe
itself. Since it resembles the interstellar gas and dust that are thought to
have been created in the "Big Bang," studies of Jupiter may help scientists
calibrate models of the beginning of the universe.
Though starlike in composition, Jupiter is too small to generate
temperatures high enough to ignite nuclear fusion, the process that powers
the stars. Some scientists believe that the sun and Jupiter began as
unequal partners in a binary star system. (If a double star system had
developed, it is unlikely life could have arisen in the solar system.) While
in a sense a "failed star," Jupiter is almost as large as a planet can be. If
it contained more mass, it would not have grown larger, but would have shrunk
from compression by its own gravity. If it were 100 times more massive,
thermonuclear reactions would ignite, and Jupiter would be a star.
For a brief period after its formation, Jupiter was much hotter, more
luminous, and about 10 times larger than it is now, scientists believe. Soon
after accretion (the condensation of a gas and dust cloud into a planet), its
brightness dropped from about one percent of the Sun's to about one
billionth -- a decline of ten million times.
In its present state Jupiter emits about twice as much heat as it
receives from the Sun. The loss of this heat -- residual energy left over
from the compressive heat of accretion -- means that Jupiter is cooling and
losing energy at a tremendously rapid rate. Temperatures in Jupiter's core,
which were about 90,000 degrees Fahrenheit in the planet's hot, early
phase, are now about 54,000 degrees Fahrenheit, 100 times hotter than any
terrestrial surface, but 500 times cooler than the temperature at the
center of the sun. Temperatures on Jupiter now range from 54,000 degrees
Fahrenheit at the core to minus 248 degrees Fahrenheit at the top of the
cloud banks.
Mainly uniform in composition, Jupiter's structure is determined by
gradations in temperature and pressure. Deep in Jupiter's interior there is
thought to be a small rocky core, comprising about four percent of the
planet's mass. This "small" core (about the size of 10 Earths) is surrounded
by a 25,000-mile-thick layer of liquid metallic hydrogen. (Metallic
hydrogen is liquid, but sufficiently compressed to behave as metal.)
Motions of this liquid "metal" are the source of the planet's enormous
magnetic field. This field is created by the same dynamo effect found in
the metallic cores of Earth and other planets.
At the outer limit of the metallic hydrogen layer, pressures equal three
million times that of Earth's atmosphere and the temperature has cooled to
19,000 degrees Fahrenheit.
Surrounding the central metallic hydrogen region is an outer shell of
"liquid" molecular hydrogen. Huge pressures compress Jupiter's gaseous
hydrogen until, at this level, it behaves like a liquid. The liquid hydrogen
layer extends upward for about 15,000 miles. Then it gradually becomes
gaseous. This transition region between liquid and gas marks, in a sense,
where the solid and liquid planet ends and its atmosphere begins.
From here, Jupiter's atmosphere extends up for 600 more miles, but only
in the top 50 miles are found the brilliant bands of clouds for which Jupiter
is known. The tops of these bands are colored bright yellow, red and orange
from traces of phosphorous and sulfur. Five or six of these bands,
counterflowing east and west, encircle the planet in each hemisphere. At
one point near Jupiter's equator, east winds of 220 mph blow right next to
west winds of 110 mph. At boundaries of these bands, rapid changes in
wind speed and direction create large areas of turbulence and shear. These
are the same forces that create tornados here on Earth. On Jupiter, these
"baroclinic instabilities" are major phenomena, creating chaotic, swirling
winds and spiral features such as White Ovals.
The brightest cloud banks, known as zones, are believed to be higher,
cooler areas where gases are ascending. The darker bands, called belts, are
thought to be warmer, cloudier regions of descent.
The top cloud layer consists of white cirrus clouds of ammonia crystals,
at a pressure six-tenths that of Earth's atmosphere at sea level (.6 bar).
Beneath this layer, at a pressure of about two Earth atmospheres (2 bars)
and a temperature of near minus 160 degrees Fahrenheit, a reddish-brown
cloud of ammonium hydrosulfide is predicted.
At a pressure of about 6 bars, there are believed to be clouds of water
and ice. However, recent Earth-based spectroscopic studies suggest that
there may be less water on Jupiter than expected. While scientists
previously believed Jupiter and the sun would have similar proportions of
water, recent work indicates there may be 100 times less water on Jupiter
than if it had a solar mixture of elements. If this is the case, there may be
only a thin layer of water-ice at the 6 bar level.
However, Jupiter's cloud structure, except for the highest layer of
ammonia crystals, remains uncertain. The height of the lower clouds is
still theoretical -- clouds are predicted to lie at the temperature levels
where their assumed constituents are expected to condense. The Galileo
probe will make the first direct observations of Jupiter's lower atmosphere
and clouds, providing crucial information.
The forces driving Jupiter's fast-moving winds are not well understood
yet. The classical explanation holds that strong currents are created by
convection of heat from Jupiter's hot interior to the cooler polar regions,
much as winds and ocean currents are driven on Earth, from equator to
poles. But temperature differences do not fully explain wind velocities
that can reach 265 mph. An alternative theory is that pressure differences,
due to changes in the thermodynamic state of hydrogen at high and low
temperatures, set up the wind jets.
Jupiter's rapid rotation rate is thought to have effects on wind velocity
and to produce some of Jupiter's bizarre circulation patterns, including
many spiral features. These rotational effects are known as
manifestations of the Coriolis force. Coriolis force is what determines the
spin direction of weather systems. It basically means that on the surface
of a sphere (a planet), a parcel of gas farther from the poles has a higher
rotational velocity around the planet than a parcel closer to the poles. As
gases then move north or south, interacting parcels with different
velocities produce vortices (whirlpools). This may account for some of
Jupiter's circular surface features.
Jupiter spins faster than any planet in the solar system. Though 11 times
Earth's diameter, Jupiter spins more than twice as fast (once in 10 hours),
giving gases on the surface extremely high rates of travel -- 22,000 mph at
the equator, compared with 1000 mph for air at Earth's equator. Jupiter's
rapid spin also causes this gas and liquid planet to flatten markedly at the
poles and bulge at the equator.
Visible at the top of Jupiter's atmosphere are eye-catching features
such as the famous Great Red Spot and the exotic White Ovals, Brown
Barges and White Plumes. The Great Red Spot, which is 25,000 miles wide
and large enough to swallow three Earths, is an enormous oval eddy of
swirling gases. It is driven by two counter-flowing jet streams, which
pass, one on each side of it, moving in opposite directions, each with speeds
of 100-200 mph. The Great Red Spot was first discovered in 1664, by the
British scientist Roger Hook, using Galileo's telescope. In the three
centuries since, the huge vortex has remained constant in latitude in
Jupiter's southern equatorial belt. Because of its stable position,
astronomers once thought it might be a volcano.
Another past theory compared the Great Red Spot to a gigantic hurricane.
However, the GRS rotates anti-cyclonically while hurricanes are cyclonic
features (counterclockwise in the northern hemisphere, clockwise in the
southern) -- and the dynamics of the Great Red Spot appear unrelated to
moisture.
The Great Red Spot most closely resembles an enormous tornado, a huge
vortex that sucks in smaller vortices. The Coriolis effect created by
Jupiter's fast spin, appears to be the key to the dynamics that drive the
spot.
The source of the Great Red Spot's color remains a mystery. Many
scientists now believe it to be caused by phosphorus, but its spectral line
does not quite match that of phosphorus. The GRS may be the largest in a
whole array of spiral phenomena with similar dynamics. About a dozen
white ovals, circulation patterns resembling the GRS, exist in the southern
latitudes of Jupiter and appear to be driven by the same forces. Scientists
do not know why these ovals are white.
Scientists believe the brown barges, which appear like dark patches on
the planet, are holes in the upper clouds, through which the reddish-brown
lower cloud layer may be glimpsed. The equatorial plumes, or white
plumes, may be a type of wispy cirrus anvil cloud.
GALILEO MANAGEMENT
The Galileo Project is managed for NASA's Office of Space Science and
Applications by the NASA Jet Propulsion Laboratory, Pasadena, Calif. This
responsibility includes designing, building, testing, operating and tracking
Galileo. NASA's Ames Research Center, Moffett Field, Calif. is responsible
for the atmosphere probe, which was built by Hughes Aircraft Company, El
Segundo, Calif.
The probe project and science teams will be stationed at Ames during
pre-mission, mission operations, and data reduction periods. Team
members will be at Jet Propulsion Laboratory for probe entry.
The Federal Republic of Germany has furnished the orbiter's
retropropulsion module and is participating in the scientific investigations.
The radioisotope thermoelectric generators were designed and built for the
U.S. Department of Energy by the General Electric Company.
STS-34 INERTIAL UPPER STAGE (IUS-19)
The Inertial Upper Stage (IUS) will again be used with the Space Shuttle,
this time to transport NASA's Galileo spacecraft out of Earth's orbit to
Jupiter, a 2.5-billion-mile journey.
The IUS has been used previously to place three Tracking and Data Relay
Satellites in geostationary orbit as well as to inject the Magellan
spacecraft into its interplanetary trajectory to Venus. In addition, the IUS
has been selected by the agency for the Ulysses solar polar orbit mission.
After 2 1/2 years of competition, Boeing Aerospace Co., Seattle, was
selected in August 1976 to begin preliminary design of the IUS. The IUS
was developed and built under contract to the Air Force Systems Command's
Space Systems Division. The Space Systems Division is executive agent for
all Department of Defense activities pertaining to the Space Shuttle
system. NASA, through the Marshall Space Flight Center, Huntsville, Ala.,
purchases the IUS through the Air Force and manages the integration
activities of the upper stage to NASA spacecraft.
Specifications
IUS-19, to be used on mission STS-34, is a two-stage vehicle weighing
approximately 32,500 lbs. Each stage has a solid rocket motor (SRM),
preferred over liquid-fueled engines because of SRM's relative simplicity,
high reliability, low cost and safety.
The IUS is 17 ft. long and 9.25 ft. in diameter. It consists of an aft
skirt, an aft stage SRM generating approximately 42,000 lbs. of thrust, an
interstage, a forward-stage SRM generating approximately 18,000 lbs. of
thrust, and an equipment support section.
Airborne Support Equipment
The IUS Airborne Support Equipment (ASE) is the mechanical, avionics
and structural equipment located in the orbiter. The ASE supports the IUS
and the Galileo in the orbiter payload bay and elevates the combination for
final checkout and deployment from the orbiter.
The IUS ASE consists of the structure, electromechanical mechanisms,
batteries, electronics and cabling to support the Galileo/IUS. These ASE
subsystems enable the deployment of the combined vehicle; provide,
distribute and/or control electrical power to the IUS and spacecraft;
provide plumbing to cool the radioisotope thermoelectric generator (RTG)
aboard Galileo; and serve as communication paths between the IUS and/or
spacecraft and the orbiter.
IUS Structure
The IUS structure is capable of supporting loads generated internally and
also by the cantilevered spacecraft during orbiter operations and the IUS
free flight. It is made of aluminum skin-stringer construction, with
longerons and ring frames.
Equipment Support Section
The top of the equipment support section contains the spacecraft
interface mounting ring and electrical interface connector segment for
mating and integrating the spacecraft with the IUS. Thermal isolation is
provided by a multilayer insulation blanket across the interface between
the IUS and Galileo.
The equipment support section also contains the avionics which provide
guidance, navigation, control, telemetry, command and data management,
reaction control and electrical power. All mission-critical components of
the avionics system, along with thrust vector actuators, reaction control
thrusters, motor igniter and pyrotechnic stage separation equipment are
redundant to assure reliability of better than 98 percent.
IUS Avionics Subsystems
The avionics subsystems consist of the telemetry, tracking and
command subsystems; guidance and navigation subsystem; data
management; thrust vector control; and electrical power subsystems.
These subsystems include all the electronic and electrical hardware used to
perform all computations, signal conditioning, data processing and
formatting associated with navigation, guidance, control, data and
redundancy management. The IUS avionics subsystems also provide the
equipment for communications between the orbiter and ground stations as
well as electrical power distribution.
Attitude control in response to guidance commands is provided by thrust
vectoring during powered flight and by reaction control thrusters while
coasting. Attitude is compared with guidance commands to generate error
signals. During solid motor firing, these commands gimble the IUS's
movable nozzle to provide the desired pitch and yaw control. The IUS's roll
axis thrusters maintain roll control. While coasting, the error signals are
processed in the computer to generate thruster commands to maintain the
vehicle's altitude or to maneuver the vehicle.
The IUS electrical power subsystem consists of avionics batteries, IUS
power distribution units, a power transfer unit, utility batteries, a
pyrotechnic switching unit, an IUS wiring harness and umbilical and staging
connectors. The IUS avionics system provides 5-volt electrical power to
the Galileo/IUS interface connector for use by the spacecraft telemetry
system.
IUS Solid Rocket Motors
The IUS two-stage vehicle uses a large solid rocket motor and a small
solid rocket motor. These motors employ movable nozzles for thrust vector
control. The nozzles provide up to 4 degrees of steering on the large motor
and 7 degrees on the small motor. The large motor is the longest-thrusting
duration SRM ever developed for space, with the capability to thrust as long
as 150 seconds. Mission requirements and constraints (such as weight) can
be met by tailoring the amount of propellant carried. The IUS-19
first-stage motor will carry 21,488 lb. of propellant; the second stage
6,067 lb.
Reaction Control System
The reaction control system controls the Galileo/IUS spacecraft attitude
during coasting, roll control during SRM thrustings, velocity impulses for
accurate orbit injection and the final collision-avoidance maneuver after
separation from the Galileo spacecraft.
As a minimum, the IUS includes one reaction control fuel tank with a
capacity of 120 lb. of hydrazine. Production options are available to add a
second or third tank. However, IUS-19 will require only one tank.
IUS To Spacecraft Interfaces
Galileo is physically attached to the IUS at eight attachment points,
providing substantial load-carrying capability while minimizing the
transfer of heat across the connecting points. Power, command and data
transmission between the two are provided by several IUS interface
connectors. In addition, the IUS provides a multilayer insulation blanket of
aluminized Kapton with polyester net spacers across the Galileo/IUS
interface, along with an aluminized Beta cloth outer layer. All IUS thermal
blankets are vented toward and into the IUS cavity, which in turn is vented
to the orbiter payload bay. There is no gas flow between the spacecraft and
the IUS. The thermal blankets are grounded to the IUS structure to prevent
electrostatic charge buildup.
Flight Sequence
After the orbiter payload bay doors are opened in orbit, the orbiter will
maintain a preselected attitude to keep the payload within thermal
requirements and constraints.
On-orbit predeployment checkout begins, followed by an IUS command link
check and spacecraft communications command check. Orbiter trim
maneuvers are normally performed at this time.
Forward payload restraints will be released and the aft frame of the
airborne-support equipment will tilt the Galileo/IUS to 29 degrees. This
will extend the payload into space just outside the orbiter payload bay,
allowing direct communication with Earth during systems checkout. The
orbiter then will be maneuvered to the deployment attitude. If a problem
has developed within the spacecraft or IUS, the IUS and its payload can be
restowed.
Prior to deployment, the spacecraft electrical power source will be
switched from orbiter power to IUS internal power by the orbiter flight
crew. After verifying that the spacecraft is on IUS internal power and that
all Galileo/IUS predeployment operations have been successfully completed,
a GO/NO-GO decision for deployment will be sent to the crew from ground
support.
When the orbiter flight crew is given a "Go" decision, they will activate
the ordnance that separates the spacecraft's umbilical cables. The crew
then will command the electromechanical tilt actuator to raise the tilt
table to a 58-degree deployment position. The orbiter's RCS thrusters will
be inhibited and an ordnance-separation device initiated to physically
separate the IUS/spacecraft combination from the tilt table.
Six hours, 20 minutes into the mission, compressed springs provide the
force to jettison the IUS/Galileo from the orbiter payload bay at
approximately 6 inches per second. The deployment is normally performed
in the shadow of the orbiter or in Earth eclipse.
The tilt table then will be lowered to minus 6 degrees after IUS and its
spacecraft are deployed. A small orbiter maneuver is made to back away
from IUS/Galileo. Approximately 15 minutes after deployment, the
orbiter's OMS engines will be ignited to move the orbiter away from its
released payload.
After deployment, the IUS/Galileo is controlled by the IUS onboard
computers. Approximately 10 minutes after IUS/Galileo deployment from
the orbiter, the IUS onboard computer will send out signals used by the IUS
and/or Galileo to begin mission sequence events. This signal will also
enable the IUS reaction control system. All subsequent operations will be
sequenced by the IUS computer, from transfer orbit injection through
spacecraft separation and IUS deactivation.
After the RCS has been activated, the IUS will maneuver to the required
thermal attitude and perform any required spacecraft thermal control
maneuvers.
At approximately 45 minutes after deployment from the orbiter, the
ordnance inhibits for the first SRM will be removed. The belly of the
orbiter already will have been oriented towards the IUS/Galileo to protect
orbiter windows from the IUS's plume. The IUS will recompute the first
ignition time and maneuvers necessary to attain the proper attitude for the
first thrusting period. When the proper transfer orbit opportunity is
reached, the IUS computer will send the signal to ignite the first stage
motor 60 minutes after deployment. After firing approximately 150
seconds, the IUS first stage will have expended its propellant and will be
separated from the IUS second stage.
Approximately 140 seconds after first-stage burnout, the second- stage
motor will be ignited, thrusting about 108 seconds. The IUS second stage
then will separate and perform a final collision/contamination avoidance
maneuver before deactivating.
SHUTTLE SOLAR BACKSCATTER ULTRAVIOLET INSTRUMENT
The Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument was
developed by NASA to calibrate similar ozone measuring space-based
instruments on the National Oceanic and Atmospheric Administration's
TIROS satellites (NOAA-9 and -11).
The SSBUV will help scientists solve the problem of data reliability
caused by calibration drift of solar backscatter ultraviolet (SBUV)
instruments on orbiting spacecraft. The SSBUV uses the Space Shuttle's
orbital flight path to assess instrument performance by directly comparing
data from identical instruments aboard the TIROS spacecraft, as the
Shuttle and the satellite pass over the same Earth location within a 1-hour
window. These orbital coincidences can occur 17 times per day.
The SBUV measures the amount and height distribution of ozone in the
upper atmosphere. It does this by measuring incident solar ultraviolet
radiation and ultraviolet radiation backscattered from the Earth's
atmosphere. The SBUV measures these parameters in 12 discrete
wavelength channels in the ultraviolet. Because ozone absorbs in the
ultraviolet, an ozone measurement can be derived from the ratio of
backscatter radiation at different wavelengths, providing an index of the
vertical distribution of ozone in the atmosphere.
Global concern over the depletion of the ozone layer has sparked
increased emphasis on developing and improving ozone measurement
methods and instruments. Accurate, reliable measurements from space are
critical to the detection of ozone trends and for assessing the potential
effects and development of corrective measures.
The SSBUV missions are so important to the support of Earth science
that six additional missions have been added to the Shuttle manifest for
calibrating ozone instruments on future TIROS satellites. In addition, the
dates of the four previously manifested SSBUV flights have been
accelerated.
The SSBUV instrument and its dedicated electronics, power, data and
command systems are mounted in the Shuttle's payload bay in two Get Away
Special canisters, an instrument canister and a support canister. Together,
they weigh approximately 1200 lb. The instrument canister holds the
SSBUV, its specially designed aspect sensors and in-flight calibration
system. A motorized door assembly opens the canister to allow the SSBUV
to view the sun and Earth and closes during the in-flight calibration
sequence.
The support canister contains the power system, data storage and
command decoders. The dedicated power system can operate the SSBUV for
a total of approximately 40 hours.
The SSBUV is managed by NASA's Goddard Space Flight Center, Greenbelt,
Md. Ernest Hilsenrath is the principal investigator.
GROWTH HORMONE CONCENTRATIONS
AND DISTRIBUTION IN PLANTS
The Growth Hormone Concentration and Distribution in Plants (GHCD)
experiment is designed to determine the effects of microgravity on the
concentration, turnover properties, and behavior of the plant growth
hormone, Auxin, in corn shoot tissue (Zea Mays).
Mounted in foam blocks inside two standard middeck lockers, the
equipment consists of four plant cannisters, two gaseous nitrogen freezers
and two temperature recorders. Equipment for the experiment, excluding
the lockers, weighs 97.5 pounds.
A total of 228 specimens (Zea Mays seeds) are "planted" in special
filter, paper-Teflon tube holders no more than 56 hours prior to flight. The
seeds remain in total darkness throughout the mission.
The GHCD experiment equipment and specimens will be prepared in a
Payload Processing Facility at KSC and placed in the middeck lockers. The
GHCD lockers will be installed in the orbiter middeck within the last 14
hours before launch.
No sooner than 72 hours after launch, mission specialist Ellen Baker will
place two of the plant cannisters into the gaseous nitrogen freezers to
arrest the plant growth and preserve the specimens. The payload will be
restowed in the lockers for the remainder of the mission.
After landing, the payload must be removed from the orbiter within 2
hours and will be returned to customer representatives at the landing site.
The specimens will be examined post flight for microgravity effects.
The GHCD experiment is sponsored by NASA Headquarters, the Johnson
Space Center and Michigan State University.
POLYMER MORPHOLOGY
The Polymer Morphology (PM) experiment is a 3M-developed organic
materials processing experiment designed to explore the effects of
microgravity on polymeric materials as they are processed in space.
Since melt processing is one of the more industrially significant
methods for making products from polymers, it has been chosen for study in
the PM experiment. Key aspects of melt processing include polymerization,
crystallization and phase separation. Each aspect will be examined in the
experiment. The polymeric systems for the first flight of PM include
polyethelyne, nylon-6 and polymer blends.
The apparatus for the experiment includes a Fournier transform infrared
(FTIR) spectrometer, an automatic sample manipulating system and a
process control and data acquisition computer known as the Generic
Electronics Module (GEM). The experiment is contained in two separate,
hermetically sealed containers that are mounted in the middeck of the
orbiter. Each container includes an integral heat exchanger that transfers
heat from the interior of the containers to the orbiter's environment. All
sample materials are kept in triple containers for the safety of the
astronauts.
The PM experiment weighs approximately 200 lb., occupies three
standard middeck locker spaces (6 cubic ft., total) in the orbiter and
requires 240 watts to operate.
Mission specialists Franklin R. Chang-Diaz and Shannon W. Lucid are
responsible for the operation of the PM experiment on orbit. Their interface
with the PM experiment is through a small, NASA-supplied laptop computer
that is used as an input and output device for the main PM computer. This
interface has been programmed by 3M engineers to manage and display the
large quantity of data that is available to the crew. The astronauts will
have an active role in the operation of the experiment.
In the PM experiment, infrared spectra (400 to 5000 cm-1) will be
acquired from the FTIR by the GEM computer once every 3.2 seconds as the
materials are processed on orbit. During the 100 hours of processing time,
approximately 2 gigabytes of data will be collected. Post flight, 3M
scientists will process the data to reveal the effects of microgravity on
the samples processed in space.
The PM experiment is unique among material processing experiments in
that measurements characterizing the effects of microgravity will be made
in real time, as the materials are processed in space.
In most materials processing space experiments, the materials have
been processed in space with little or no measurements made during
on-orbit processing and the effects of microgravity determined post facto.
The samples of polymeric materials being studied in the PM experiment
are thin films (25 microns or less) approximately 25 mm in diameter. The
samples are mounted between two infrared transparent windows in a
specially designed infrared cell that provides the capability of thermally
processing the samples to 200 degrees Celsius with a high degree of
thermal control. The samples are mounted on a carousel that allows them
to be positioned, one at a time, in the infrared beam where spectra may be
acquired. The GEM provides all carousel and sample cell control. The first
flight of PM will contain 17 samples.
The PM experiment is being conducted by 3M's Space Research and
Applications Laboratory. Dr. Earl L. Cook is 3M's Payload Representative and
Mission Coordinator. Dr. Debra L. Wilfong is PM's Science Coordinator, and
James E. Steffen is the Hardware Coordinator.
The PM experiment, a commercial development payload, is sponsored by
NASA's Office of Commercial Programs. The PM experiment will be 3M's
fifth space experiment and the first under the company's 10-year Joint
Endeavor Agreement with NASA for 62 flight experiment opportunities.
Previous 3M space experiments have studied organic crystal growth from
solution (DMOS/1 on mission STS 51-A and DMOS/2 on STS 61-B) and
organic thin film growth by physical vapor treatment (PVTOS/1 on STS 51-I
and PVTOS/2 on mission STS-26).
STUDENT EXPERIMENT
Zero Gravity Growth of Ice Crystals From Supercooled Water With Relation
To Temperature (SE82-15)
This experiment, proposed by Tracy L. Peters, formerly of Ygnacio High
School, Concord, Calif., will observe the geometric ice crystal shapes
formed at supercooled temperatures, below 0 degrees Celsius, without the
influence of gravity.
Liquid water has been discovered at temperatures far below water's
freezing point. This phonomenon occurs because liquid water does not have
a nucleus, or core, around which to form the crystal. When the ice freezes
at supercold temperatures, the ice takes on many geometric shapes based
on the hexagon. The shape of the crystal primarily depends on the
supercooled temperature and saturation of water vapor. The shapes of
crystals vary from simple plates to complex prismatic crystals.
Many scientists have tried to determine the relation between
temperature and geometry, but gravity has deformed crystals, caused
convection currents in temperature-controlled apparatus, and caused faults
in the crystalline structure. These all affect crystal growth by either rapid
fluctuations of temperature or gravitational influence of the crystal
geometry.
The results of this experiment could aid in the design of radiator cooling
and cryogenic systems and in the understanding of high-altitude
meteorology and planetary ring structure theories.
Peters is now studying physics at the University of California at Berkeley.
His teacher advisor is James R. Cobb, Ygnacio High School; his sponsor is
Boeing Aerospace Corp., Seattle.
Peters also was honored as the first four-time NASA award winner at the
International Science and Engineering Fair (ISEF), which recognizes
student's creative scientific endeavors in aerospace research. At the 1982
ISEF, Peters was one of two recipients of the Glen T. Seaborg Nobel Prize
Visit Award, an all-expense-paid visit to Stockholm to attend the Nobel
Prize ceremonies, for his project "Penetration and Diffusion of Supersonic
Fluid."
MESOSCALE LIGHTNING EXPERIMENT
The Space Shuttle will again carry the Mesoscale Lightning Experiment
(MLE), designed to obtain nighttime images of lightning in order to better
understand the global distribution of lightning, the interrelationships
between lightning events in nearby storms, and relationships between
lightning, convective storms and precipitation.
A better understanding of the relationships between lightning and
thunderstorm characteristics can lead to the development of applications in
severe storm warning and forecasting, and early warning systems for
lightning threats to life and property.
In recent years, NASA has used both Space Shuttle missions and
high-altitude U-2 aircraft to observe lightning from above convective
storms. The objectives of these observations have been to determine some
of the baseline design requirements for a satellite-borne optical lightning
mapper sensor; study the overall optical and electrical characteristics of
lightning as viewed from above the cloudtop; and investigate the
relationship between storm electrical development and the structure,
dynamics and evolution of thunderstorms and thunderstorm systems.
The MLE began as an experiment to demonstrate that meaningful,
qualitative observations of lightning could be made from the Shuttle.
Having accomplished this, the experiment is now focusing on quantitative
measurements of lightning characteristics and observation simulations for
future space-based lightning sensors.
Data from the MLE will provide information for the development of
observation simulations for an upcoming polar platform and Space Station
instrument, the Lightning Imaging Sensor (LIS). The lightning experiment
also will be helpful for designing procedures for using the Lightning Mapper
Sensor (LMS), planned for several geostationary platforms.
In this experiment, Atlantis' payload bay camera will be pointed
directly below the orbiter to observe nighttime lightning in large, or
mesoscale, storm systems to gather global estimates of lightning as
observed from Shuttle altitudes. Scientists on the ground will analyze the
imagery for the frequency of lightning flashes in active storm clouds
within the camera's field of view, the length of lightning discharges, and
cloud brightness when illuminated by the lightning discharge within the
cloud.
If time permits during missions, astronauts also will use a handheld
35mm camera to photograph lightning activity in storm systems not
directly below the Shuttle's orbital track.
Data from the MLE will be associated with ongoing observations of
lightning made at several locations on the ground, including observations
made at facilities at the Marshall Space Flight Center, Huntsville, Ala.;
Kennedy Space Center, Fla.; and the NOAA Severe Storms Laboratory,
Norman, Okla. Other ground-based lightning detection systems in Australia,
South America and Africa will be intergrated when possible.
The MLE is managed by the Marshall Space Flight Center. Otha H. Vaughan
Jr., is coordinating the experiment. Dr. Hugh Christian is the project
scientist, and Dr. James Arnold is the project manager.
IMAX
The IMAX project is a collaboration between NASA and the Smithsonian
Institution's National Air and Space Museum to document significant space
activities using the IMAX film medium. This system, developed by the IMAX
Systems Corp., Toronto, Canada, uses specially designed 70mm film
cameras and projectors to record and display very high definition
large-screen color motion pictures.
IMAX cameras previously have flown on Space Shuttle missions 41-C,
41-D and 41-G to document crew operations in the payload bay and the
orbiter's middeck and flight deck along with spectacular views of space and
Earth.
Film from those missions form the basis for the IMAX production, "The
Dream is Alive." On STS 61-B, an IMAX camera mounted in the payload bay
recorded extravehicular activities in the EAS/ACCESS space construction
demonstrations.
The IMAX camera, most recently carried aboard STS-29, will be used on
this mission to cover the deployment of the Galileo spacecraft and to
gather material on the use of observations of the Earth from space for
future IMAX films.
AIR FORCE MAUI OPTICAL SITE CALIBRATION TEST
The Air Force Maui Optical Site (AMOS) tests allow ground-based
electro-optical sensors located on Mt. Haleakala, Maui, Hawaii, to collect
imagery and signature data of the orbiter during cooperative overflights.
Scientific observations made of the orbiter while performing Reaction
Control System thruster firings, water dumps or payload bay light
activation are used to support the calibration of the AMOS sensors and the
validation of spacecraft contamination models. AMOS tests have no
payload-unique flight hardware and only require that the orbiter be in
predefined attitude operations and lighting conditions.
The AMOS facility was developed by Air Force Systems Command (AFSC)
through its Rome Air Development Center, Griffiss Air Force Base, N.Y., and
is administered and operated by the AVCO Everett Research Laboratory,
Maui. The principal investigator for the AMOS tests on the Space Shuttle is
from AFSC's Air Force Geophysics Laboratory, Hanscom Air Force Base,
Mass. A co-principal investigator is from AVCO.
Flight planning and mission support activities for the AMOS test
opportunities are provided by a detachment of AFSC's Space Systems
Division at Johnson Space Center, Houston. Flight operations are conducted
at JSC Mission Control Center in coordination with the AMOS facilities
located in Hawaii.
SENSOR TECHNOLOGY EXPERIMENT
The Sensor Technology Experiment (STEX) is a radiation detection
experiment designed to measure the natural radiation background. The STEX
is a self-contained experiment with its own power, sensor, computer
control and data storage. A calibration pack, composed of a small number
of passive threshold reaction monitors, is attached to the outside of the
STEX package.
Sponsored by the Strategic Defense Initiative Organization, the STEX
package weighs approximately 50 pounds and is stowed in a standard
middeck locker throughout the flight.
PAYLOAD AND VEHICLE WEIGHTS
Vehicle/Payload Weight (Pounds)
Orbiter (Atlantis) Empty 172,018
Galileo/IUS (payload bay) 43,980
Galileo support hardware (middeck) 59
SSBUV (payload bay) 637
SSBUV support 578
DSO 49
DTO 170
GHCD 130
IMAX 269
MLE 15
PM 219
SSIP 70
STEX 52
Orbiter and Cargo at SRB Ignition 264,775
Total Vehicle at SRB Ignition 4,523,810
Orbiter Landing Weight 195,283
SPACEFLIGHT TRACKING AND DATA NETWORK
Primary communications for most activities on STS-34 will be
conducted through the orbiting Tracking and Data Relay Satellite System
(TDRSS), a constellation of three communications satellites in
geosynchronous orbit 22,300 miles above the Earth. In addition, three NASA
Spaceflight Tracking and Data Network (STDN) ground stations and the NASA
Communications Network (NASCOM), both managed by Goddard Space Flight
Center, Greenbelt, Md., will play key roles in the mission.
Three stations -- Merritt Island and Ponce de Leon, Florida and the
Bermuda -- serve as the primary communications during the launch and
ascent phases of the mission. For the first 80 seconds, all voice, telemetry
and other communications from the Space Shuttle are relayed to the
mission managers at Kennedy and Johnson Space Centers by way of the
Merritt Island facility.
At 80 seconds, the communications are picked up from the Shuttle and
relayed to the two NASA centers from the Ponce de Leon facility, 30 miles
north of the launch pad. This facility provides the communications between
the Shuttle and the centers for 70 seconds, or until 150 seconds into the
mission. This is during a critical period when exhaust from the solid rocket
motors "blocks out" the Merritt Island antennas.
The Merritt Island facility resumes communications to and from the
Shuttle after those 70 seconds and maintains them until 6 minutes, 30
seconds after launch when communications are "switched over" to Bermuda.
Bermuda then provides the communications until 11 minutes after liftoff
when the TDRS-East satellite acquires the Shuttle. TDRS-West acquires
the orbiter at launch plus 50 minutes.
The TDRS-East and -West satellites will provide communications with
the Shuttle during 85 percent or better of each orbit. The TDRS-West
satellite will handle communications with the Shuttle during its descent
and landing phases.
CREW BIOGRAPHIES
Donald E. Williams, 47, Capt., USN, will serve as commander. Selected as
an astronaut in January 1978, he was born in Lafayette, Ind.
Williams was pilot for STS-51D, the fourth flight of Discovery, launched
April 12, 1985. During the mission, the seven-member crew deployed the
Anik-C communications satellite for Telesat of Canada and the Syncom
IV-3 satellite for the U.S. Navy. A malfunction in the Syncom spacecraft
resulted in the first unscheduled extravehicular, rendezvous and proximity
operation for the Space Shuttle in an attempt to activate the satellite.
He graduated from Otterbein High School, Otterbein, Ind., in 1960 and
received his B.S. degree in mechanical engineering from Purdue University
in 1964. Williams completed his flight training at Pensacola, Fla.,
Meridian, Miss., and Kingsville, Texas, and earned his wings in 1966.
During the Vietnam Conflict, Williams completed 330 combat missions.
He has logged more than 5,400 hours flying time, including 5,100 in jets,
and 745 aircraft carrier landings.
Michael J. McCulley, 46, Cdr., USN, will be pilot on this flight. Born in
San Diego, McCulley considers Livingston, Tenn., his hometown. He was
selected as a NASA astronaut in 1984. He is making his first Space Shuttle
flight.
McCulley graduated from Livingston Academy in 1961. He received B.S.
and M.S. degrees in metallurgical engineering from Purdue University in
1970.
After graduating from high school, McCulley enlisted in the U.S. Navy and
subsequently served on one diesel-powered and two nuclear-powered
submarines. Following flight training, he served tours of duty in A-4 and
A-65 aircraft and was selected to attend the Empire Test Pilots School in
Great Britain. He served in a variety of test pilot billets at the Naval Air
Test Center, Patuxent River, Md., before returning to sea duty on the USS
Saratoga and USS Nimitz.
He has flown more than 50 types of aircraft, logging more than 4,760
hours, and has almost 400 carrier landings on six aircraft carriers.
Shannon W. Lucid, 46, will serve as mission specialist (MS-1) on this,
her second Shuttle flight. Born in Shanghai, China, she considers Bethany,
Okla., her hometown. Lucid is a member of the astronaut class of 1978.
Lucid's first Shuttle mission was during STS 51-G, launched from the
Kennedy Space Center on June 17, 1985. During that flight, the crew
deployed communications satellites for Mexico, the Arab League and the
United States.
Lucid graduated from Bethany High School in 1960. She then attended
the University of Oklahoma where she received a B.S. degree in chemistry in
1963, an M.S. degree in biochemistry in 1970 and a Ph.D. in biochemistry in
1973.
Before joining NASA, Lucid held a variety of academic assignments such
as teaching assistant at the University of Oklahoma's department of
chemistry; senior laboratory technician at the Oklahoma Medical Research
Foundation; chemist at Kerr-McGee in Oklahoma City; graduate assistant in
the University of Oklahoma Health Science Center's department of
biochemistry; and molecular biology and research associate with the
Oklahoma Medical Research Foundation in Oklahoma City. Lucid also is a
commercial, instrument and multi-engine rated pilot.
Franklin Chang-Diaz, 39, will serve as MS-2. Born in San Jose, Costa
Rica, Chang-Diaz also will be making his second flight since being selected
as an astronaut in 1980.
Chang-Diaz made his first flight aboard Columbia on mission STS 61-C,
launched from KSC Jan. 12, 1986. During the 6-day flight he participated in
the deployment of the SATCOM KU satellite, conducted experiments in
astrophysics and operated the materials science laboratory, MSL-2.
Chang-Diaz graduated from Colegio De La Salle, San Jose, Costa Rica, in
1967, and from Hartford High School, Hartford, Conn., in 1969. He received
a B.S. degree in mechanical engineering from the University of Connecticut
in 1973 and a Ph.D. in applied plasma physics from the Massachusetts
Institute of Technology in 1977.
While attending the University of Connecticut, Chang-Diaz also worked
as a research assistant in the physics department and participated in the
design and construction of high-energy atomic collision experiments. Upon
entering graduate school at MIT, he became heavily involved in the United
State's controlled fusion program and conducted intensive research in the
design and operation of fusion reactors. In 1979, he developed a novel
concept to guide and target fuel pellets in an inertial fusion reactor
chamber. In 1983, he was appointed as visiting scientist with the MIT
Plasma Fusion Center which he visits periodically to continue his research
on advanced plasma rockets.
Chang-Diaz has logged more than 1,500 hours of flight time, including
1,300 hours in jet aircraft.
Ellen S. Baker, 36, will serve as MS-3. She will be making her first
Shuttle flight. Baker was born in Fayetteville, N.C., and was selected as an
astronaut in 1984.
Baker graduated from Bayside High School, New York, N.Y., in 1970. She
received a B.A. degree in geology from the State University of New York at
Buffalo in 1974, and an M.D. from Cornell University in 1978.
After medical school, Baker trained in internal medicine at the
University of Texas Health Science Center in San Antonio, Texas. In 1981,
she was certified by the American Board of Internal Medicine.
Baker joined NASA as a medical officer at the Johnson Space Center in
1981 after completing her residency. That same year, she graduated with
honors from the Air Force Aerospace Medicine Primary Course at Brooks Air
Force Base in San Antonio. Prior to her selection as an astronaut, she
served as a physician in the Flight Medicine Clinic at JSC.
NASA PROGRAM MANAGEMENT
NASA Headquarters
Washington, D.C.
Richard H. Truly
NASA Administrator
William B. Lenoir
Acting Associate Administrator for Space Flight
George W.S. Abbey
Deputy Associate Administrator for Space Flight
Johnson Space Center
Houston, Texas
Paul J. Weitz
Deputy Director
Eugene F. Kranz
Director, Mission Operations
Kennedy Space Center
Florida
Robert L. Crippen
Deputy Director, NSTS Operations
|
| 560.18 | Awestruck... | CTD016::J_BUTLER | Leave it better than you found it... | Thu Oct 05 1989 11:49 | 39 |
| Incredible! I am absolutely in awe of the technology required to
allow the probe section to decelerate from 115Kmph to less than
.5Kmph in less than 2 minutes AND return usable data for 75 more
minutes!! I am aware of the problems (and beaucoup time+megabucks)
spent in developing reliable and survivable electronics for various
artillery launched projectiles which are far, far cruder than the
probe section of Galileo!
But, despite my natural optimism and enthusiasm for all parts of
the Space Program, this apparent leap forward in technology seems
inconsistent with our demonstrated capabilities!
NASA doesn't sink its hard-fought-for money into wild shots or blind
chance, but I can't imagine the US (or anybody else) building such a
craft!
So, my questions are:
1. Were any parts of the probe subjected to real tests (as opposed
to computer simulations) of the stresses expected? If so, how?
If not, then how can we expect a reasonable chance of the probe's
survival? Scientifically, bumblebees can't fly, either, but they
do quite well in their practical demonstrations!
2. What is the nature of the heat shield that it could withstand
temperatures of 28,000 degrees F? (and weigh LESS than 750 pounds????)
3. If we are flying a 'best guess' probe, has NASA entered an era
of greater risk-taking with these expensive, but unmanned, flights?
If the probe works as planned at Jupiter it would rank as one of
the Great Accomplishments (caps intended) of history!
The 90s ARE going to be exciting, aren't they!
Ad Astra!
John B.
|
| 560.19 | | DECWIN::FISHER | Burns Fisher 381-1466, ZKO3-4/W23 | Fri Oct 06 1989 17:46 | 7 |
| Yep...pretty impressive all right. Note that there was a set of probes sent
to Venus, although they were, I'm sure, not subjected to anything like this kind
of deceleration since Venus is not such a big planet to be sucking them down.
As I recall, they did not have parachutes either, yet at least one survived the
"landing" and continued to transmit data for a few minutes!
Burns
|
| 560.20 | | MEMIT::SCOLARO | Fusion in a Glass! | Fri Oct 06 1989 17:59 | 8 |
| Just saw in the paper, our friend HUGO did not impact launch schedule,
still set for oct 12.
The only thing that could now hold it up, barring normal system and
weather problems, is a possible stupid court
challange to launching a rtg.
Tony
|
| 560.21 | | PAXVAX::MAIEWSKI | | Fri Oct 06 1989 19:22 | 31 |
| I was looking at the following schedule and I've been trying to figure
out just what Galileo's orbits around the sun look like. It would appear that
Galileo does a 1/2 elipse from Earth to Venus from October to Feburary.
That makes sense since Earth's orbit is 12 months and Venus' orbit is
a little less.
However, it seems that it takes a long time (10 months) to get back to Earth.
If it's inside the orbit of Earth, one orbit around the sun could be 10 months,
but after 10 months it would be back near the orbit of Venus, not Earth.
Is it possible that Galileo is making more than one orbit around the sun
between it's encounters with Venus and Earth? That would make some sense.
Anyway, the schedule is reproduced below from the previous note.
George
GALILEO MISSION EVENTS
Launch Window (Atlantis and IUS) Oct. 12 to Nov. 21, 1989
(Note: for both asteroids, closes in mid-October)
Venus flyby ( 9,300 mi) *Feb. 9, 1990
Venus data playback Oct. 1990
Earth 1 flyby ( about 600 mi) *Dec. 8, 1990
Asteroid Gaspra flyby (600 mi) *Oct. 29, 1991
Earth 2 flyby (200 mi) *Dec. 8, 1992
Asteroid Ida flyby (600 mi) *Aug. 28, 1993
Probe release July 1995
Jupiter arrival Dec. 7, 1995
(includes Io flyby, probe entry and relay, Jupiter orbit insertion)
Orbital tour of Galilean satellites Dec '95-Oct '97
|
| 560.22 | A Bigger Orbit | VOSTOK::LEPAGE | Truth travels slowly | Fri Oct 06 1989 20:01 | 9 |
| Re:.21
After Galileo's flyby of Venus, Galileo's orbit will become larger
and more elliptical (as well as rotate the line of the apsides and
other things). In any case, Galileo will have to make a little over a
half a revolution in this bigger orbit hence the 10 months to reach
Earth again.
Drew
|
| 560.23 | RE 560.19 | RENOIR::KLAES | N = R*fgfpneflfifaL | Fri Oct 06 1989 20:02 | 14 |
| The GALILEO atmosphere probe *is* going to use a parachute in
its descent through the Jovian atmosphere.
Regarding the PIONEER VENUS landers, all of them (save the main
bus, which burned up upon entry into Venus' atmosphere) had braking
parachutes used in their descents through the atmosphere. The Day
probe actually survived impact on the surface (the parachutes were
ejected far above the ground) for 67 minutes, until it succumbed to
the 480 degree Celsius (900 degree Fahrenheit) heat. It is believed
the Day probe survived because it landed in a thick field of dust or
sand. This mission took place in December of 1978.
Larry
|
| 560.24 | | PAXVAX::MAIEWSKI | | Fri Oct 06 1989 21:23 | 13 |
| RE 22
Ten months still seems like a long time. Earth will make almost a
complete revolution from the time Galileo leaves Venus until it passes
Earth. Does Galileo's path take it outside of Earth's orbit?
The 4 month part from Earth to Venus sounds right, the 2 year part
from earth to earth is easy to visualize as is the trip to Jupiter. But
I'm having a real hard time trying to form a picture in my mind, or on
paper, of that 10 month trip from Venus to Earth that is little more
than a half elipse.
George
|
| 560.25 | | DECWIN::FISHER | Burns Fisher 381-1466, ZKO3-4/W23 | Sat Oct 07 1989 00:47 | 7 |
| Well, I meant "didn't have parachute either" in the sense of "didn't
have parachutes as Galileo does". I did not remember that the Venus
probes had chutes on the way down; only that they did not have them
at the end. Thanks for the extra info.
Burns
|
| 560.26 | Venus Digression | LHOTSE::DAHL | Tom Dahl, CDMS | Mon Oct 09 1989 12:27 | 10 |
| Regarding landers on Venus, the Soviets have been pretty successful at it. At
least four have survived landing. Venera's 9, 10, 13, and 14 I believe. Each
one returned a panoramic photograph of the Venusian surface. The visible
features vary a fair amount between the images. Some places are covered with
very slabby rocks, others are more sandy/soily.
The Veneras had a sort of ring skirt surrounting the waist of the craft, used
for aerodynamic deceleration. This was a permanent fixture, maybe six inches
to a foot wide (radially extending flat, horizontally around amidships).
-- Tom
|
| 560.27 | Status Mon 9-Oct | STAR::HUGHES | | Mon Oct 09 1989 14:56 | 12 |
| At 9am, the countdown running on time with no anomalies. The count started with
all pre-countdown activities completed which is a little unusual (there are
normally a few items held over until the first hold).
Weather predictions indicate a 25% chance of launch constraints on the 12th,
either cloud cover below 8000 feet or winds too high for an RTLS abort.
Since the launch window on the 12th is only 10 minutes, there will an extra
30 minute hold programmed into the countdown.
gary
|
| 560.28 | RE 560.26 | RENOIR::KLAES | N = R*fgfpneflfifaL | Mon Oct 09 1989 15:38 | 11 |
| The Soviets have had more than just the probes you mention
surviving the landing on Venus's surface: The ones you listed are
the landers which took photographs of the surface.
The other successful Soviet Venus probe landers have been VENERA
7, 8, 11, 12, and VEGA 1 and 2 (also known as VENERA 17 and 18).
The Soviets plan on sending more Venus landers before the end of
this century (they're concentrating on exploring Mars for now).
Larry
|
| 560.29 | GALILEO Update - October 6 | CLIPR::KLAES | N = R*fgfpneflfifaL | Mon Oct 09 1989 18:55 | 91 |
| Newsgroups: sci.space,sci.space.shuttle
Subject: Galileo Update - October 6.
Date: 9 Oct 89 17:21:37 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO DAILY REPORT
6 OCTOBER 1989
General
Spacecraft
CDS memory loading on logic power was completed successfully on 3
and 4 October.
On 4 October, the spacecraft was turned on so as to be able to
verify L-20 min discrete from the IUS after the changeout of the IUS
computer A.
In addition, both the spacecraft and the IUS performed stray
voltage tests to the spacecraft to insure the super zip detonator
block connector pins have no voltage while the spacecraft and the IUS
is on.
In the early morning of 5 October, the super zip detonator block
firing cables were connected to the spacecraft and FTK checks were
performed thus completing all of the spacecraft pryotechnic preflight
activities.
In the early morning of 6 October, closeout operations were
performed; PWS dipole antennas were installed, the science purge was
transferred to the T-0 source via the 4 way valve. The cabling to the
spacecraft from the support equipment simulated RTG power supply was
disconnected and the final spacecraft cleanliness inspection and
cleaning was performed. The only remaining mechanical activity is the
disconnection and capping of the carry-on umbilicals, and the
installation of the related thermal blanket.
LCET
LCET #1 CDS ground support computer was exercised to assure that
spacecraft memory loading was functioning; memory loading by the
computer was successful.
RTG Cooling Loop
Vacuum drying of the payload portion of the cooling loop is still
on-going; results to date indicate that the "dry" specifications will
be satisfied prior to servicing the loop with water/alcohol.
STS
IUS: On 4 October, the IUS went into their ordnance operations
at the completion of the computer A replacement and retest. The
ordnance operations were reported as having been completed satisfactorily.
Schedule Discussion and Assessment
As discussed in the report of 4 October, a new payload schedule
has been issued. The highlights of the schedule are as follows:
4 Oct-5 Oct IUS/GLL closeout operations
6 Oct 0800-1600 RTG preparations for transfer to Pad
1000-1400 Payload contamination inspection and
cleaning
6 Oct-7 Oct 1600-0200 Reconfigure PGHM for RTG operations
7 Oct 0200-0500 JPL Launch Complex 39-B preparations
for RTG operations
1700-1900 Transport RTGs to Pad B
7 Oct-8 Oct 1900-0700 Install RTGs in spacecraft and
air bath operations
8 Oct 0400-1600 Galileo Launch Conditioning
0600-2100 RTG Coolant Servicing Functional
Test
9 Oct 0400-0600 Disconnect Galileo carry-on
umbilicals and final closeout
9 Oct 0800 Launch Countdown start L-76 hr
T-43 hr
|
| 560.30 | Status Tues 10-Oct, 9am | STAR::HUGHES | | Tue Oct 10 1989 15:49 | 8 |
| As of 9am, the countdown was proceeding on schedule.
Overnight, problems were detected in Main Engine Controller #2 which may require
a changeout. A spare is available at the Cape.
No change in weather predictions.
gary
|
| 560.31 | | STAR::BANKS | Zoot Mutant | Tue Oct 10 1989 16:47 | 1 |
| Any news yet of today's court case with the shuttle-stopping luddites?
|
| 560.32 | | VCSESU::COOK | I'm the CIA | Tue Oct 10 1989 17:22 | 9 |
|
I haven't heard anything either, but they had the pathetic luddite
on TV this morning saying that if they did not win today they would
appeal.
HAHA! They expect to get an appeal hearing by tommorrow?
/prc
|
| 560.33 | | STAR::BANKS | Zoot Mutant | Tue Oct 10 1989 19:14 | 5 |
| I'd also heard them say that if they lose, they'll have a sit-in at the lauching
pad to prevent NASA from lauching.
Huh. If they could talk Dan Rather into covering it in person, it might not be
too difficult to find someone to press the "launch" button anyway. :-) :-)
|
| 560.34 | | PAXVAX::MAIEWSKI | | Tue Oct 10 1989 20:37 | 13 |
| RE <<< Note 560.32 by VCSESU::COOK "I'm the CIA" >>>
> HAHA! They expect to get an appeal hearing by tommorrow?
Yes they can. They are asking for a temporary injunction to stop the launch
until such time as it can come to trial. They can get a hearing right away
for that sort of thing.
The judges would have to decide that they do not have a prima facea case in
order to let the launch proceed. I think the odds are with the launch, but not
by a lot. I'm keeping my fingers crossed.
George
|
| 560.35 | GALILEO Update - October 9 | RENOIR::KLAES | N = R*fgfpneflfifaL | Tue Oct 10 1989 21:02 | 97 |
| Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Galileo Update
Date: 10 Oct 89 00:10:29 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO DAILY REPORT
9 OCTOBER 1989
NOTE: This report covers the activities of 6-9 October.
General
Spacecraft
The RTGs were installed on 7 and 8 October. Spacecraft Launch
Conditioning was subsequently performed and completed successfully.
Final spacecraft closeouts have been performed. The spacecraft
is now in a complete ready state for launch; the discrete from the IUS
at L-20 min. is the only remaining prelaunch command to be sent.
STS
IUS: The only scheduled operation was the open circuit voltage
checks on the flight batteries. This was completed successfully on 7
October.
The PLBD (payload bay doors) were closed at approximately 12:45
p.m. on 9 October.
Details
Spacecraft
At 0200 hours on 7 October, JPL performed the final preparations
for RTG installations at Launch Complex 39B. During the removal of the
end-blocks (used for testing the cooling loop when the RTGs are not
installed) from the ACS (Airborne Cooling System), a JPL technician
alertly detected a foreign object in the supply side to the RTG
cooling line. Approximately 40 psi of nitrogen pressure was used in an
unsuccessful attempt to clear the line. The pressure was subsequently
reduced to approximately 20 psi and hemostats were used to remove the
debris which was later identified as a piece of foam porous pad. The
foam pads are used to temporarily seal the lines from contamination
any time a joint of the system plumbing is broken. This is the same
type of material previously reported as the cause of the earlier RTG
cooling loop problem (see Report #78).
Meetings were held between JPL and Lockheed engineers/managers.
It was decided to perform a boroscope examination of the sharp bends
of the cooling system immediate interface to the RTG. Test results
showed the bends to be clean. Based on these results and the fact
that approximately equal nitrogen flow was obtained through each RTG
branch with a nitrogen flow, it was decided to proceed with the
installation of the RTGs without any additional action.
The RTGs were delivered to the base of the launch pad at
approximately 6:30 p.m. 7 October. The first RTG was hoisted to the
PCR (Payload Changeout Room) but operations were then interrupted for
approximately 1 1/2 hours by lightning storms. The -x RTG was then
installed without any problems except during the mating of the PRD
(pressure release devices) to the RTGs; the screw lengths were too
long and two additional washers had to be installed on each of the two
screws. The second RTG was then hoisted and installed without any
problems; washers were also installed on the PRD screws. The
operation was completed at approximately 2:30 a.m. on 8 October.
At 0400 hours on 8 October, during the process of applying the
planned short to the -x RTG by an external S.E. box, it was discovered
that the meter went to approximately 25 volts instead of near zero.
The spare shorting box was then used and the appropriate reading
obtained. The problem was later found to be in the meter. The
process for applying RTG power to the spacecraft continued without any
further problems.
At the conclusion of powering the spacecraft from the RTGs, at
approximately 0610 hours on 8 October, the conditioning of the
spacecraft for launch commenced. Launch conditioning was completed at
approximtely 6:00 p.m. on 8 October. Memory compares of the
spacecraft memory contents to the memory load have been completed and
it has been reported as being successful at approximately 0300 hours
on 9 October.
The PRD safe pins have been removed on 9 October and the carry-on
umbilicals disconnected. The spacecraft portion of the carry-on
umbilical connectors have been capped and the related thermal blanket
installed.
The PGHM and RTG installation platforms have been placed in a
configuration that allowed the orbiter PLBD (payload bay doors) to be
closed; the PLBDs were closed at approximately 12:30 p.m. on 9 October.
Schedule Discussion and Assessment
Launch is still scheduled for 12 October at 1:29 p.m. EDT.
|
| 560.36 | Revised STS-34 NASA Press Kit | RENOIR::KLAES | N = R*fgfpneflfifaL | Tue Oct 10 1989 21:08 | 2629 |
| Newsgroups: sci.space
Subject: STS-34 Press Kit [Complete and Revised].
Date: 9 Oct 89 19:18:01 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
[The NASA HQ newsroom informs me that the earlier version of the
Press Kit they posted was mangled (I though it looked strange :-)).
Therefore, I'm posting the cleaned-up, corrected version. -PEY]
NASA
SPACE SHUTTLE MISSION STS-34
PRESS KIT
OCTOBER 1989
PUBLIC AFFAIRS CONTACTS
Sarah Keegan/Barbara Selby
Office of Space Flight
NASA Headquarters, Washington, D.C.
Charles Redmond/Paula Cleggett-Haleim
Office of Space Science and Applications
NASA Headquarters, Washington, D.C.
Jim Ball
Office of Commercial Programs
NASA Headquarters, Washington, D.C.
Lisa Malone
Kennedy Space Center, Fla.
Kyle Herring
Johnson Space Center, Houston, Texas
Jerry Berg
Marshall Space Flight Center, Huntsville, Ala.
Mack Herring
Stennis Space Center, Bay St. Louis, Miss.
Nancy Lovato
Ames-Dryden Flight Research Facility, Edwards, Calif.
Robert J. MacMillin
Jet Propulsion Laboratory, Pasadena, Calif.
Jim Elliott
Goddard Space Flight Center, Greenbelt, Md.
Peter W. Waller
Ames Research Center, Mountain View, Calif.
CONTENTS
GENERAL RELEASE
GENERAL INFORMATION
STS-34 QUICK LOOK
LAUNCH PREPARATIONS, COUNTDOWN & LIFTOFF
MAJOR COUNTDOWN MILESTONES
TRAJECTORY SEQUENCE OF EVENTS
SPACE SHUTTLE ABORT MODES
SUMMARY OF MAJOR ACTIVITIES
LANDING AND POST LANDING OPERATIONS
GALILEO
GALILEO MISSION EVENTS
EARTH TO JUPITER
VENUS
FIRST EARTH PASS
FIRST ASTEROID
SECOND EARTH PASS
SECOND ASTEROID
APPROACHING JUPITER
AT JUPITER
The probe at Jupiter
The orbiter at Jupiter
SCIENTIFIC ACTIVITIES
Spacecraft scientific activities
Probe scientific activities
Orbiter scientific activities
GROUND SYSTEMS
SPACECRAFT CHARACTERISTICS
JUPITER'S SYSTEM
WHY JUPITER INVESTIGATIONS ARE IMPORTANT
GALILEO MANAGEMENT
GALILEO ORBITER AND PROBE SCIENTIFIC INVESTIGATIONS
STS-34 INERTIAL UPPER STAGE (IUS-19)
Specifications
Airborne Support Equipment
IUS Structure
Equipment Support Section
IUS Avionics Subsystems
IUS Solid Rocket Motors
Reaction Control System
IUS to Spacecraft Interfaces
Flight Sequence
SHUTTLE SOLAR BACKSCATTER ULTRAVIOLET INSTRUMENT (SSBUV)
GROWTH HORMONE CONCENTRATIONS AND DISTRIBUTION IN PLANTS
POLYMER MORPHOLOGY
STUDENT EXPERIMENT
MESOSCALE LIGHTNING EXPERIMENT
IMAX
AIR FORCE MAUI OPTICAL SITE CALIBRATION TEST
SENSOR TECHNOLOGY EXPERIMENT
PAYLOAD AND VEHICLE WEIGHTS
SPACEFLIGHT TRACKING AND DATA NETWORK
STS-34 CARGO CONFIGURATION
CREW BIOGRAPHIES
NASA PROGRAM MANAGEMENT
GENERAL RELEASE
RELEASE: 89-151
SHUTTLE ATLANTIS TO DEPLOY GALILEO PROBE TOWARD JUPITER
Space Shuttle mission STS-34 will deploy the Galileo planetary
exploration spacecraft into low-Earth orbit starting Galileo on its
journey to explore Jupiter. Galileo will be the second planetary
probe deployed from the Shuttle this year following Atlantis'
successful launch of Magellan toward Venus exploration in May.
Following deployment about 6 hours after launch, Galileo will be
propelled on a trajectory, known as Venus-Earth-Earth Gravity Assist
(VEEGA) by an Air Force-developed, inertial upper stage (IUS).
Galileo's trajectory will swing around Venus, the sun and Earth before
Galileo makes it's way toward Jupiter.
Flying the VEEGA track, Galileo will arrive at Venus in February 1990.
During the flyby, Galileo will make measurements to determine the
presence of lightning on Venus and take time-lapse photography of Venus'
cloud circulation patterns. Accelerated by Venus' gravity, the spacecraft
will head back to Earth.
Enroute, Galileo will activate onboard remote-sensing equipment to
gather near-infrared data on the composition and characteristics of the
far side of Earth's moon. Galileo also will map the hydrogen distribution
of the Earth's atmosphere.
Acquiring additional energy from the Earth's gravitational forces,
Galileo will travel on a 2-year journey around the sun spending 10 months
inside an asteroid belt. On Oct. 29, 1991, Galileo wlll pass within 600
miles of the asteroid Gaspra.
On the second Earth flyby in December 1992, Galileo will photograph
the north pole of the moon in an effort to determine if ice exists.
Outbound, Galileo will activate the time-lapse photography system to
produce a "movie" of the moon orbiting Earth.
Racing toward Jupiter, Galileo will make a second trek through the
asteroid belt passing within 600 miles of asteroid Ida on Aug. 29, 1993.
Science data gathered from both asteroid encounters will focus on surface
geology and composition.
Five months prior to the Dec. 7, 1995, arrival at Jupiter, Galileo's
atmospheric probe, encased in an oval heat shield, will spin away from the
orbiter at a rate of 5 revolutions per minute (rpm) and follow a ballistic
trajectory aimed at a spot 6 degrees north of Jupiter's equator. The probe
will enter Jupiter's atmosphere at a shallow angle to avoid burning up like
a meteor or ricocheting off the atmosphere back into space.
At approximately Mach 1 speed, the probe's pilot parachute will deploy,
removing the deceleration module aft cover. Deployment of the main
parachute will follow, pulling the descent module out of the aeroshell to
expose the instrument-sensing elements. During the 75-minute descent
into the Jovian atmosphere, the probe will use the orbiter to transmit
data back to Earth. After 75 minutes, the probe will be crushed under the
heavy atmospheric pressure.
The Galileo orbiter will continue its primary mission, orbiting around
Jupiter and four of its satellites, returning science data for the next 22
months.
Galileo's scientific goals include the study of the chemical
composition, state and dynamics of the Jovian atmosphere and satellites,
and the investigation of the structure and physical dynamics of the
powerful Jovian magnetosphere.
Overall responsibility for management of the project, including orbiter
development, resides at NASA's Jet Propulsion Laboratory, Pasadena,
Calif. The NASA Ames Research Center, Mountain View, Calif., manages
the probe system. JPL built the 2,500-lb. spacecraft and Hughes Aircraft
Co. built the 740-lb. probe.
Modifications made to Galileo since flight postponement in 1986
include the addition of sunshields to the base and top of the antenna, new
thermal control surfaces, blankets and heaters. Because of the extended
length of the mission, the electrical circuitry of the thermoelectric
generator has been revised to reduce power demand throughout the
mission to assure adequate power supply for mission completion.
Joining Galileo in the payload bay of Atlantis will be the Shuttle Solar
Backscatter Ultraviolet (SSBUV) instrument. The SSBUV is designed to
provide calibration of backscatter ultraviolet instruments currently being
flown on free-flying satellites. SSBUV's primary objective is to check the
calibration of the ozone sounders on satellites to verify the accuracy of
the data set of atmospheric ozone and solar irradiance data.
The SSBUV is contained in two Get Away Special canisters in the
payload bay and weighs about 1219 lbs . One canister contains the SSBUV
spectrometer and five supporting optical sensors. The second canister
houses data, command and power systems. An interconnecting cable
provides the communication link between the two canisters.
Atlantis also will carry several secondary payloads involving radiation
measurements, polymer morphology, lightning research, microgravity
effects on plants and a student experiment on ice crystal growth in space.
Commander of the 31st Shuttle mission is Donald E. Williams, Captain,
USN. Michael J. McCulley, Commander, USN, is Pilot. Williams flew as
Pilot of mission STS 51-D in April 1985. McCulley will be making his
first Shuttle flight.
Mission Specialists are Shannon W. Lucid, Ph.D.; Franklin R. Chang-Diaz,
Ph.D.; and Ellen S. Baker, M.D. Lucid previously flew as a Mission
Specialist on STS 51-G in June 1985. Chang-Diaz flew as a Mission
Specialist on STS 61-C in January 1986. Baker is making her first Shuttle
flight.
Liftoff of the fifth flight of orbiter Atlantis is scheduled for 1:29 p.m.
EDT on Oct. 12 from Kennedy Space Center, Fla., launch pad 39-B, into a
160-nautical-mile, 34.3-degree orbit. Nominal mission duration is 5
days, 2 hours, 45 minutes. Deorbit is planned on orbit 81, with landing
scheduled for 4:14 p.m. EDT on Oct. 17 at Edwards Air Force Base, Calif.
Liftoff on Oct. 12 could occur during a 10-minute period. The launch
window grows each day reaching a maximum of 47 minutes on Nov. 2. The
window then decreases each day through the remainder of the launch
opportunity which ends Nov. 21. The window is dictated by the need for a
daylight landing opportunity at the trans-Atlantic landing abort sites and
the performance constraint of Galileo's inertial upper stage.
After landing at Edwards AFB, Atlantis will be towed to the NASA
Ames-Dryden Flight Research Facility, hoisted atop the Shuttle Carrier
Aircraft and ferried back to the Kennedy Space Center to begin processing
for its next flight.
GENERAL INFORMATION
NASA Select Television Transmission
NASA Select television is available on Satcom F-2R, Transponder 13,
C-band located at 72 degrees west longitude, frequency 3960.0 MHz,
vertical polarization, audio monaural 6.8 MHz.
The schedule for tv transmissions from the orbiter and for the
change-of-shift briefings from Johnson Space Center, Houston, will be
available during the mission at Kennedy Space Center, Fla.; Marshall Space
Flight Center, Huntsville, Ala.; Johnson Space Center; and NASA
Headquarters, Washington, D.C. The schedule will be updated daily to
reflect changes dictated by mission operations.
TV schedules also may be obtained by calling COMSTOR, 713/483-5817.
COMSTOR is a computer data base service requiring the use of a telephone
modem. Voice updates of the TV schedule may be obtained by dialing
202/755-1788. This service is updated daily at noon EDT.
Special Note to Broadcasters
In the 5 workdays before launch, short sound bites of astronaut interviews
with the STS-34 crew will be available to broadcasters by calling
202/755-1788 between 8 a.m. and noon EDT.
Status Reports
Status reports on countdown and mission progress, on-orbit activities and
landing operations will be produced by the appropriate NASA news center.
Briefings
An STS-34 mission press briefing schedule will be issued prior to launch.
During the mission, flight control personnel will be on 8-hour shifts.
Change-of-shift briefings by the off-going flight director will occur at
approximately 8-hour intervals.
STS-34 QUICK LOOK
Launch Date: Oct. 12, 1989
Launch Window: 1:29 p.m. - 1:39 p.m. EDT
Launch Site: Kennedy Space Center, Fla., Pad 39B
Orbiter: Atlantis (OV-104)
Altitude: 160 nm
Inclination: 34.30 degrees
Duration: 5 flight days
Landing Date/Time: Oct. 17, 1989, 4:14 p.m. EDT
Primary Landing Site: Edwards AFB, Calif.
Abort Landing Sites:
Return to Launch Site - Kennedy Space Center, Fla.
Transoceanic Abort Landing - Ben Guerir, Morocco
Abort Once Around - Edwards AFB, Calif.
Crew:
Donald E. Williams, Commander
Michael J. McCulley, Pilot
Shannon W. Lucid, Mission Specialist
Ellen S. Baker, Mission Specialist
Franklin R. Chang-Diaz, Mission Specialist
Cargo Bay Payloads:
Galileo spacecraft to Jupiter (primary payload)
Shuttle Solar Backscatter Ultraviolet (SSBUV)
Middeck Payloads:
Growth Hormone Concentration & Distribution in Plants (GHCD)
Mesoscale Lightning Experiment (MLR)
Polymer Morphology (PM)
Sensor Technology Experiment (STEX)
LAUNCH PREPARATIONS, COUNTDOWN AND LIFTOFF
Processing activities began on Atlantis for the STS-34 mission on May
16 when Atlantis was towed to Orbiter Processing Facility (OPF) bay 2
after arrival from NASA's Ames-Dryden Flight Research Facility in
California. STS-30 post-flight deconfiguration and inspections were
conducted in the processing hangar.
As planned, the three main engines were removed the last week of May
and taken to the main engine shop in the Vehicle Assembly Building (VAB)
for the replacement of several components including the high pressure
oxidizer turbopumps. The engines were reinstalled the first week of July,
while the ship was in the OPF. Engine 2027 is installed in the number one
position, engine 2030 is in the number two position and engine 2029 is in
the number three position.
The right hand Orbital Maneuvering System (OMS) pod was removed in
mid-June for repairs. A propellant tank needed for Atlantis' pod was
scheduled for delivery too late to support integrated testing. As a result,
Discovery's right pod was installed on Atlantis about 2 weeks later. The
left OMS pod was removed July 9 and reinstalled 2 1/2 weeks later. Both
pods had dynatubes and helium isolation valve repairs in the Hypergolic
Maintenance Facility.
About 34 modifications have been implemented since the STS-30
mission. One significant modification is a cooling system for the
radioisotope thermoelectric generators (RTG). The RTG fuel is plutonium
dioxide which generates heat as a result of its normal decay. The heat is
converted to energy and used to provide electrical power for the Galileo
spacecraft. A mixture of alcohol and water flows in the special cooling
system to lower the RTG case temperature and maintain a desired
temperature to the payload instrumentation in the vicinity of the RTGs.
These cooling lines are mounted on the port side of the orbiter from the
aft compartment to a control panel in bay 4.
Another modification, called "flutter buffet," features special
instrumentation on the vertical tail and right and left outboard elevons.
Ten accelerometers were added to the vertical tail and one on each of the
elevons. These instruments are designed to measure in-flight loads on the
orbiter's structure. Atlantis is the only vehicle that will be equipped with
this instrumentation.
Improved controllers for the water spray boilers and auxiliary power
units were installed. Other improvements were made to the orbiter's
structure and thermal protection system, mechanical systems, propulsion
system and avionics system.
Stacking of solid rocket motor (SRM) segments for flight began with
the left aft booster on Mobile Launcher Platform 1 in the VAB on June 15.
Booster stacking operations were completed by July 22 and the external
tank was mated to the two boosters on July 30.
Flight crew members performed the Crew Equipment Interface Test on
July 29 to become familiar with Atlantis' crew compartment, vehicle
configuration and equipment associated with the mission.
The Galileo probe arrived at the Spacecraft Assembly and
Encapsulation Facility (SAEF) 2 on April 17 and the spacecraft arrived on
May 16. While at SAEF-2, the spacecraft and probe were joined and tested
together to verify critical connections. Galileo was delivered to the
Vertical Processing Facility (VPF) on Aug. 1. The Inertial Upper Stage
(IUS) was delivered to the VPF on July 30. The Galileo/IUS were joined
together on Aug. 3 and all integrated testing was performed during the
second week of August.
The Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment,
contained in two Get Away Special (GAS) canisters, was mounted on a
special GAS beam in Atlantis' payload bay on July 24. Interface
verification tests were performed the next day.
Atlantis was transferred from the OPF to the VAB on Aug. 21, where it
was mated to the external tank and SRBs. A Shuttle Interface Test was
conducted in the VAB to check the mechanical and electrical connections
between the various elements of the Shuttle vehicle and onboard flight
systems.
The assembled Space Shuttle vehicle was rolled out of the VAB aboard
its mobile launcher platform for the 4.2 mile trip to Launch Pad 39-B on
Aug. 29. Galileo and its IUS upper stage were transferred from the VPF to
Launch Pad 39-B on Aug. 25. The payload was installed in Atlantis'
payload bay on Aug. 30.
The payload interface verification test was planned for Sept. 7 to
verify connections between the Shuttle and the payload. An end-to-end
test was planned for Sept. 8 to verify communications between the
spacecraft and ground controllers. Testing of the IUS was planned about 2
weeks prior to launch in parallel with Shuttle launch preparations.
A Countdown Demonstration Test, a dress rehearsal for the STS-34
flight crew and KSC launch team, is designed as a practice countdown for
the launch. At press time, it was planned for Sept. 14 and 15.
One of the unique STS-34 processing milestones planned was a
simulation exercise for the installation of the RTGs. Simulated RTGs
were to be used in the 2-day event scheduled within the first week after
Atlantis arrives at the launch pad. The test is designed to give workers
experience for the installation of the RTGs, a first in the Shuttle program.
In addition, access requirements will be identified and procedures will be
verified.
Another test scheduled at the pad is installation of the flight RTGs and
an associated test and checkout of the RTG cooling system planned for the
third week of September. This test will verify the total RTG cooling
system and connections. The RTGs will be removed at the completion of
the 3-day cooling system test and returned to the RTG facility. The two
flight RTGs will be reinstalled on the spacecraft 6 days before launch.
Launch preparations scheduled the last 2 weeks prior to launch
countdown include final vehicle ordnance activities, such as power-on
stray-voltage checks and resistance checks of firing circuits; loading the
fuel cell storage tanks; pressurizing the hypergolic propellant tanks
aboard the vehicle; final payload closeouts; and a final functional check of
the range safety and SRB ignition, safe and arm devices.
The launch countdown is scheduled to pick up at the T-minus 43-hour
mark, leading up to the STS-34 launch. Atlantis' fifth launch will be
conducted by a joint NASA/industry team from Firing Room 1 in the Launch
Control Center.
MAJOR COUNTDOWN MILESTONES
Countdown Event
T-43 Hours Power up Space Shuttle vehicle.
T-34 Hours Begin orbiter and ground support
equipment closeouts for launch.
T-30 Hours Activate orbiter's navigation aids.
T-27 Hours (holding) Enter first built-in hold for 8 hours.
T-27 Hours (counting) Begin preparations for loading fuel
cell storage tanks with liquid oxygen
and liquid hydrogen reactants.
T-25 Hours Load orbiter's fuel cell tanks with
liquid oxygen.
T-22 Hours, 30 minutes Load orbiter's fuel cell tanks with
liquid hydrogen.
T-22 Hours Perform interface check between
Houston Mission Control and Merritt
Island Launch Area (MILA) tracking
station.
T-20 Hours Activate and warm up inertial
measurement units (IMU).
T-19 Hours (holding) Enter 8-hour built-in hold. Activate
orbiter communications system.
T-19 hours (counting) Resume countdown. Continue
preparations to load external tank,
orbiter closeouts and preparations to
move the Rotating Service Structure
(RSS).
T-11 Hours (holding) Start 14-hour, 40 minute built-in hold.
Perform orbiter ascent switch list in
orbiter flight and middecks.
T-11 Hours (counting) Retract RSS from vehicle to launch
position.
T-9 Hours Activate orbiter's fuel cells.
T-8 Hours Configure Mission Control
communications for launch. Start clearing
blast danger area.
T-6 Hours, 30 minutes Perform Eastern Test Range open
loop command test.
T-6 Hours (holding) Enter 1-hour built-in hold. Receive
management "go" for tanking.
T-6 Hours (counting) Start external tank chilldown and
propellant loading.
T-5 Hours Start IMU pre-flight calibration.
T-4 Hours Perform MILA antenna alignment.
T-3 Hours (holding) 2-hour built-in hold begins. Loading
of external tank is complete and in a
stable replenish mode. Ice team
goes to pad for inspections. Closeout
crew goes to white room to begin
preparing orbiter's cabin for flight
crew's entry. Wake flight crew
(launch minus 4 hours, 55 minutes).
T-3 Hours (counting) Resume countdown.
T-2 Hours, 55 minutes Flight crew departs O&C Building for
Launch Pad 39-B (Launch minus 3
hours,15 minutes).
T-2 Hours, 30 minutes Crew enters orbiter vehicle (Launch
minus 2 Hours, 50 minutes).
T-60 minutes Start pre-flight alignment of IMUs.
T-20 minutes (holding) 10-minute built-in hold begins.
T-20 minutes (counting) Configure orbiter computers for launch.
T-10 minutes White room closeout crew cleared
through launch danger area roadblocks.
T-9 minutes (holding) 40-minute built-in hold begins. Perform
status check and receive Launch Director
and Mission Management Team "go."
T-9 minutes (counting) Start ground launch sequencer.
T-7 minutes, 30 seconds Retract orbiter access arm.
T-5 minutes Pilot starts auxiliary power units. Arm
range safety, solid rocket booster (SRB)
ignition systems.
T-3 minutes, 30 seconds Orbiter goes on internal power.
T-2 minutes, 55 seconds Pressurize liquid oxygen tank for
flight and retract gaseous oxygen
vent hood.
T-1 minute, 57 seconds Pressurize liquid hydrogen tank.
T-31 seconds "Go" from ground computer for
orbiter computers to start the
automatic launch sequence.
T-28 seconds Start SRB hydraulic power units.
T-21 seconds Start SRB gimbal profile test.
T-6.6 seconds Main engine start.
T-3 seconds Main engines at 90 percent thrust.
T-0 SRB ignition, holddown post
release and liftoff.
T+7 seconds Shuttle clears launch tower and
control switches to JSC.
Note: This countdown timeline may be adjusted in real time as necessary.
TRAJECTORY SEQUENCE OF EVENTS
____________________________________________________________________________
RELATIVE
EVENT MET VELOCITY MACH ALTITUDE
(d:h:m:s) (fps) (ft.)
Launch 00/00:00:00
Begin Roll Maneuver 00/00:00:09 165 .15 627
End Roll Maneuver 00/00:00:17 374 .33 2,898
SSME Throttle Down to 65% 00/00:00:34 833 .75 11,854
Max. Dyn. Pressure (Max Q) 00/00:00:52 1,260 1.2 28,037
SSME Throttle Up to 104% 00/00:01:01 1,499 1.49 38,681
SRB Staging 00/00:02:04 4,316 3.91 153,873
Negative Return 00/00:03:54 6,975 7.48 317,096
Main Engine Cutoff (MECO) 00/00:08:27 24,580 22.41 366,474
Zero Thrust 00/00:08:33 24,596 22.17 368,460
ET Separation 00/00:08:45
OMS 2 Burn 00/00:39:48
Galileo/IUS Deploy (orbit 5) 00/06:21:36
Deorbit Burn (orbit 81) 05/01:45:00
Landing (orbit 82) 05/02:45:00
Apogee, Perigee at MECO: 157 x 39 nm
Apogee, Perigee post-OMS 2: 161 x161 nm
Apogee, Perigee post deploy: 177 x161 nm
SPACE SHUTTLE ABORT MODES
Space Shuttle launch abort philosophy aims toward safe and intact
recovery of the flight crew, orbiter and its payload. Abort modes include:
* Abort-To-Orbit (ATO) -- Partial loss of main engine thrust late enough
to permit reaching a minimal 105-nautical mile orbit with orbital
maneuvering system engines.
* Abort-Once-Around (AOA) -- Earlier main engine shutdown with the
capability to allow one orbit around before landing at Edwards Air Force
Base, Calif.; White Sands Space Harbor (Northrup Strip), N.M.; or the
Shuttle Landing Facility (SLF) at Kennedy Space Center (KSC), Fla.
* Trans-Atlantic Abort Landing (TAL) -- Loss of two main engines midway
through powered flight would force a landing at Ben Guerir, Morocco;
Moron, Spain; or Banjul, The Gambia.
* Return-To-Launch-Site (RTLS) -- Early shutdown of one or more engines
and without enough energy to reach Ben Guerir, would result in a pitch
around and thrust back toward KSC until within gliding distance of the
SLF.
STS-34 contingency landing sites are Edwards AFB, White Sands, KSC, Ben
Guerir, Moron and Banjul.
SUMMARY OF MAJOR ACTIVITIES
Day One
Ascent
Post-insertion checkout
Pre-deploy checkout
Galileo/Inertial Upper Stage (IUS) deploy
Detailed Secondary Objective (DSO)
Polymer Morphology (PM)
Sensor Technology Experiment (STEX) activation
Day Two
Galileo/IUS backup deploy opportunity
DSO
IMAX
PM
Shuttle Solar Backscatter Ultraviolet (SSBUV) activation
Shuttle Student Involvement Program (SSIP)
Day Three
DSO
IMAX
Mesoscale Lightning Experiment (MLE)
PM
Day Four
DSO
IMAX
MLE
PM
SSBUV deactivation
Day Five
DTO/DSO
GHCD operations
PM
STEX deactivation
Flight control systems (FCS) checkout
Cabin stow
Landing preparations
Day Six
PM stow
Deorbit preparation
Deorbit burn
Landing at Edwards AFB
LANDING AND POST LANDING OPERATIONS
Kennedy Space Center, Fla., is responsible for ground operations of the
orbiter once it has rolled to a stop on the runway at Edwards Air Force
Base, Calif. Those operations include preparing the Shuttle for the return
trip to Kennedy.
After landing, the flight crew aboard Atlantis begins "safing" vehicle
systems. Immediately after wheel stop, specially garbed technicians will
first determine that any residual hazardous vapors are below significant
levels for other safing operations to proceed.
A mobile white room is moved into place around the crew hatch once it
is verified that there are no concentrations of toxic gases around the
forward part of the vehicle. The flight crew is expected to leave Atlantis
about 45 to 50 minutes after landing. As the crew exits, technicians
enter the orbiter to complete the vehicle safing activity.
Once the initial aft safety assessment is made, access vehicles are
positioned around the rear of the orbiter so that lines from the ground
purge and cooling vehicles can be connected to the umbilical panels on the
aft end of Atlantis.
Freon line connections are completed and coolant begins circulating
through the umbilicials to aid in heat rejection and protect the orbiter's
electronic equipment. Other lines provide cooled, humidified air to the
payload bay and other cavities to remove any residual fumes and provide a
safe environment inside Atlantis.
A tow tractor will be connected to Atlantis and the vehicle will be
pulled off the runway at Edwards and positioned inside the Mate/Demate
Device (MDD) at nearby Ames-Dryden Flight Research Facility. After the
Shuttle has been jacked and leveled, residual fuel cell cryogenics are
drained and unused pyrotechnic devices are disconnected prior to returning
the orbiter to Kennedy.
The aerodynamic tail cone is installed over the three main
engines, and the orbiter is bolted on top of the 747 Shuttle Carrier
Aircraft for the ferry flight back to Florida. Pending completion of
planned work and favorable weather conditions, the 747 would depart
California about 6 days after landing for the cross-country ferry flight
back to Florida. A refueling stop is necessary to complete the journey.
Once back at Kennedy, Atlantis will be pulled inside the hangar-like
facility for post-flight inspections and in-flight anomaly troubleshooting.
These operations are conducted in parallel with the start of routine
systems reverification to prepare Atlantis for its next mission.
GALILEO
Galileo is a NASA spacecraft mission to Jupiter to study the planet's
atmosphere, satellites and surrounding magnetosphere. It was named for
the Italian renaissance scientist who discovered Jupiter's major moons by
using the first astronomical telescope.
This mission will be the first to make direct measurements from an
instrumented probe within Jupiter's atmosphere and the first to conduct
long-term observations of the planet and its magnetosphere and satellites
from orbit around Jupiter. It will be the first orbiter and atmospheric
probe for any of the outer planets. On the way to Jupiter, Galileo also will
observe Venus, the Earth-moon system, one or two asteroids and various
phenomena in interplanetary space.
Galileo will be boosted into low-Earth orbit by the Shuttle Atlantis and
then boosted out of Earth orbit by a solid rocket Inertial Upper Stage. The
spacecraft will fly past Venus and twice by the Earth, using gravity
assists from the planets to pick up enough speed to reach Jupiter. Travel
time from launch to Jupiter is a little more than 6 years.
In December 1995, the Galileo atmospheric probe will conduct a brief,
direct examination of Jupiter's atmosphere, while the larger part of the
craft, the orbiter, begins a 22-month, 10-orbit tour of major satellites
and the magnetosphere, including long-term observations of Jupiter
throughout this phase.
The 2-ton Galileo orbiter spacecraft carries 9 scientific instruments.
There are another six experiments on the 750-pound probe. The spacecraft
radio link to Earth serves as an additional instrument for scientific
measurements. The probe's scientific data will be relayed to Earth by the
orbiter during the 75-minute period while the probe is descending into
Jupiter's atmosphere. Galileo will communicate with its controllers and
scientists through NASAUs Deep Space Network, using tracking stations in
California, Spain and Australia.
GALILEO MISSION EVENTS
Launch Window (Atlantis and IUS).....................Oct. 12 to Nov. 21, 1989
(Note: for both asteroids, closes in mid-October)
Venus flyby ( 9,300 mi).............................*Feb. 9, 1990
Venus data playback..................................Oct. 1990
Earth 1 flyby ( about 600 mi).......................*Dec. 8, 1990
Asteroid Gaspra flyby (600 mi)......................*Oct. 29, 1991
Earth 2 flyby (200 mi)..............................*Dec. 8, 1992
Asteroid Ida flyby (600 mi).........................*Aug. 28, 1993
Probe release........................................July 1995
Jupiter arrival......................................Dec. 7, 1995
(includes Io flyby, probe entry and relay, Jupiter orbit insertion)
Orbital tour of Galilean satellites Dec '95-Oct '97
*Exact dates may vary according to actual launch date
EARTH TO JUPITER
Galileo will make three planetary encounters in the course of its
gravity-assisted flight to Jupiter. These provide opportunities for
scientific observation and measurement of Venus and the Earth-moon
system. The mission also has a chance to fly close to one or two
asteroids, bodies which have never been observed close up, and obtain data
on other phenomena of interplanetary space.
Scientists are currently studying how to use the Galileo scientific
instruments and the limited ability to collect, store and transmit data
during the early phase of flight to make the best use of these
opportunities. Instruments designed to observe Jupiter's atmosphere from
afar can improve our knowledge of the atmosphere of Venus and sensors
designed for the study of Jupiter's moons can add to our information about
our own moon.
VENUS
The Galileo spacecraft will approach Venus early in 1990 from the
night side and pass across the sunlit hemisphere, allowing observation of
the clouds and atmosphere. Both infrared and ultraviolet spectral
observations are planned, as well as several camera images and other
remote measurements. The search for deep cloud patterns and for
lightning storms will be limited by the fact that all the Venus data must
be tape-recorded on the spacecraft for playback 8 months later.
The spacecraft was originally designed to operate between Earth and
Jupiter, where sunlight is 25 times weaker than at Earth and
temperatures are much lower. The VEEGA mission will expose the
spacecraft to a hotter environment from Earth to Venus and back.
Spacecraft engineers devised a set of sunshades to protect the craft. For
this system to work, the front end of the spacecraft must be aimed
precisely at the Sun, with the main antenna furled for protection from the
Sun's rays until after the first Earth flyby in December 1990. This
precludes the use of the Galileo high-gain antenna and therefore,
scientists must wait until the spacecraft is close to Earth to receive the
recorded Venus data, transmitted through a low-gain antenna.
FIRST EARTH PASS
Approaching Earth for the first time about 14 months after launch, the
Galileo spacecraft will observe, from a distance, the nightside of Earth
and parts of both the sunlit and unlit sides of the moon. After passing
Earth, Galileo will observe Earth's sunlit side. At this short range,
scientific data are transmitted at the high rate using only the
spacecraft's low-gain antennas. The high-gain antenna is to be unfurled
like an umbrella, and its high-power transmitter turned on and checked
out, about 5 months after the first Earth encounter.
FIRST ASTEROID
Nine months after the Earth passage and still in an elliptical solar
orbit, Galileo will enter the asteroid belt, and two months later, will have
its first asteroid encounter. Gaspra is believed to be a fairly
representative main-belt asteroid, about 10 miles across and probably
similar in composition to stony meteorites.
The spacecraft will pass within about 600 miles at a relative speed of
about 18,000 miles per hour. It will collect several pictures of Gaspra
and make spectral measurements to indicate its composition and physical
properties.
SECOND EARTH PASS
Thirteen months after the Gaspra encounter, the spacecraft will have
completed its 2-year elliptical orbit around the Sun and will arrive back
at Earth. It will need a much larger ellipse (with a 6-year period) to reach
as far as Jupiter. The second flyby of Earth will pump the orbit up to that
size, acting as a natural apogee kick motor for the Galileo spacecraft.
Passing about 185 miles above the surface, near the altitude at which
it had been deployed from the Space Shuttle almost three years earlier,
Galileo will use Earth's gravitation to change the spacecraft's flight
direction and pick up about 8,000 miles per hour in speed.
Each gravity-assist flyby requires about three rocket-thrusting
sessions, using Galileo's onboard retropropulsion module, to fine-tune the
flight path. The asteroid encounters require similar maneuvers to obtain
the best observing conditions.
Passing the Earth for the last time, the spacecraft's scientific
equipment will make thorough observations of the planet, both for
comparison with Venus and Jupiter and to aid in Earth studies. If all goes
well, there is a good chance that Galileo will enable scientists to record
the motion of the moon about the Earth while the Earth itself rotates.
SECOND ASTEROID
Nine months after the final Earth flyby, Galileo may have a second
asteroid-observing opportunity. Ida is about 20 miles across. Like
Gaspra, Ida is believed to represent the majority of main-belt asteroids in
composition, though there are believed to be differences between the two.
Relative velocity for this flyby will be nearly 28,000 miles per hour, with
a planned closest approach of about 600 miles.
APPROACHING JUPITER
Some 2 years after leaving Earth for the third time and 5 months
before reaching Jupiter, Galileo's probe must separate from the
orbiter. The spacecraft turns to aim the probe precisely for its entry
point in the Jupiter atmosphere, spins up to 10 revolutions per minute
and releases the spin-stabilized probe. Then the Galileo orbiter
maneuvers again to aim for its own Jupiter encounter and resumes its
scientific measurements of the interplanetary environment underway
since the launch more than 5 years before.
While the probe is still approaching Jupiter, the orbiter will
have its first two satellite encounters. After passing within 20,000
miles of Europa, it will fly about 600 miles above Io's volcano-torn
surface, twenty times closer than the closest flyby altitude of
Voyager in 1979.
AT JUPITER
The Probe at Jupiter
The probe mission has four phases: launch, cruise, coast and
entry-descent. During launch and cruise, the probe will be carried by the
orbiter and serviced by a common umbilical. The probe will be dormant
during cruise except for annual checkouts of spacecraft systems and
instruments. During this period, the orbiter will provide the probe with
electric power, commands, data transmission and some thermal control.
Six hours before entering the atmosphere, the probe will be shooting
through space at about 40,000 mph. At this time, its command unit
signals "wake up" and instruments begin collecting data on lightning, radio
emissions and energetic particles.
A few hours later, the probe will slam into Jupiter's atmosphere at
115,000 mph, fast enough to jet from Los Angeles to New York in 90
seconds. Deceleration to about Mach 1 -- the speed of sound -- should
take just a few minutes. At maximum deceleration as the craft slows
from 115,000 mph to 100 mph, it will be hurtling against a force 350
times Earth's gravity. The incandescent shock wave ahead of the probe
will be as bright as the sun and reach searing temperatures of up to
28,000 degrees Fahrenheit. After the aerodynamic braking has slowed the
probe, it will drop its heat shields and deploy its parachute. This will
allow the probe to float down about 125 miles through the clouds, passing
from a pressure of 1/10th that on Earth's surface to about 25 Earth
atmospheres.
About 4 minutes after probe entry into JupiterUs atmosphere, a pilot
chute deploys and explosive nuts shoot off the top section of the probe's
protective shell. As the cover whips away, it pulls out and opens the main
parachute attached to the inner capsule. What remains of the probe's
outer shell, with its massive heat shield, falls away as the parachute
slows the instrument module.
From there on, suspended from the main parachute, the probe's capsule
with its activated instruments floats downward toward the bright clouds
below.
The probe will pass through the white cirrus clouds of ammonia
crystals - the highest cloud deck. Beneath this ammonia layer probably lie
reddish-brown clouds of ammonium hydrosulfides. Once past this layer,
the probe is expected to reach thick water clouds. This lowest cloud layer
may act as a buffer between the uniformly mixed regions below and the
turbulent swirl of gases above.
Jupiter's atmosphere is primarily hydrogen and helium. For most of its
descent through Jupiter's three main cloud layers, the probe will be
immersed in gases at or below room temperature. However, it may
encounter hurricane winds up to 200 mph and lightning and heavy rain at
the base of the water clouds believed to exist on the planet. Eventually,
the probe will sink below these clouds, where rising pressure and
temperature will destroy it. The probe's active life in Jupiter's
atmosphere is expected to be about 75 minutes in length. The probe
batteries are not expected to last beyond this point, and the relaying
orbiter will move out of reach.
To understand this huge gas planet, scientists must find out about its
chemical components and the dynamics of its atmosphere. So far,
scientific data are limited to a two-dimensional view (pictures of the
planet's cloud tops) of a three-dimensional process (Jupiter's weather).
But to explore such phenomena as the planet's incredible coloring, the
Great Red Spot and the swirling shapes and high-speed motion of its
topmost clouds, scientists must penetrate Jupiter's visible surface and
investigate the atmosphere concealed in the deep-lying layers below.
A set of six scientific instruments on the probe will measure, among
other things, the radiation field near Jupiter, the temperature, pressure,
density and composition of the planet's atmosphere from its first faint
outer traces to the hot, murky hydrogen atmosphere 100 miles below the
cloud tops. All of the information will be gathered during the probe's
descent on an 8-foot parachute. Probe data will be sent to the Galileo
Orbiter 133,000 miles overhead then relayed across the half billion miles
to Deep Space Network stations on Earth.
To return its science, the probe relay radio aboard the orbiter must
automatically acquire the probe signal below within 50 seconds, with a
success probability of 99.5 percent. It must reacquire the signal
immediately should it become lost.
To survive the heat and pressure of entry, the probe spacecraft is
composed of two separate units: an inner capsule containing the
scientific instruments, encased in a virtually impenetrable outer shell.
The probe weighs 750 pounds. The outer shell is almost all heat shield
material.
The Orbiter at Jupiter
After releasing the probe, the orbiter will use its main engine to go
into orbit around Jupiter. This orbit, the first of 10 planned, will have a
period of about 8 months. A close flyby of Ganymede in July 1996 will
shorten the orbit, and each time the Galileo orbiter returns to the inner
zone of satellites, it will make a gravity-assist close pass over one or
another of the satellites, changing Galileo's orbit while making close
observations. These satellite encounters will be at altitudes as close as
125 miles above their surfaces. Throughout the 22-month orbital phase,
Galileo will continue observing the planet and the satellites and continue
gathering data on the magnetospheric environment.
SCIENTIFIC ACTIVITIES
Galileo's scientific experiments will be carried out by more than 100
scientists from six nations. Except for the radio science investigation,
these are supported by dedicated instruments on the Galileo orbiter and
probe. NASA has appointed 15 interdisciplinary scientists whose studies
include data from more than one Galileo instrument.
The instruments aboard the probe will measure the temperatures and
pressure of Jupiter's atmosphere at varying altitudes and determine its
chemical composition including major and minor constituents (such as
hydrogen, helium, ammonia, methane, and water) and the ratio of hydrogen
to helium. Jupiter is thought to have a bulk composition similar to that of
the primitive solar nebula from which it was formed. Precise
determination of the ratio of hydrogen to helium would provide an
important factual check of the Big Bang theory of the genesis of the
universe.
Other probe experiments will determine the location and structure of
Jupiter's clouds, the existence and nature of its lightning, and the amount
of heat radiating from the planet compared to the heat absorbed from
sunlight.
In addition, measurements will be made of Jupiter's numerous radio
emissions and of the high-energy particles trapped in the planet's
innermost magnetic field. These measurements for Galileo will be made
within a distance of 26,000 miles from Jupiter's cloud tops, far closer
than the previous closest approach to Jupiter by Pioneer 11. The probe
also will determine vertical wind shears using Doppler radio
measurements made of probe motions from the radio receiver aboard the
orbiter.
Jupiter appears to radiate about twice as much energy as it receives
from the sun and the resulting convection currents from Jupiter's internal
heat source towards its cooler polar regions could explain some of the
planet's unusual weather patterns.
Jupiter is over 11 times the diameter of Earth and spins about two and
one-half times faster -- a jovian day is only 10 hours long. A point on the
equator of Jupiter's visible surface races along at 28,000 mph. This rapid
spin may account for many of the bizarre circulation patterns observed on
the planet.
Spacecraft Scientific Activities
The Galileo mission and systems were designed to investigate three
broad aspects of the Jupiter system: the planet's atmosphere, the
satellites and the magnetosphere. The spacecraft is in three segments to
focus on these areas: the atmospheric probe; a non-spinning section of the
orbiter carrying cameras and other remote sensors; and the spinning main
section of the orbiter spacecraft which includes the propulsion module,
the communications antennas, main computers and most support systems
as well as the fields and particles instruments, which sense and measure
the environment directly as the spacecraft flies through it.
Probe Scientific Activities
The probe will enter the atmosphere about 6 degrees north of the
equator. The probe weighs just under 750 pounds and includes a
deceleration module to slow and protect the descent module, which
carries out the scientific mission.
The deceleration module consists of an aeroshell and an aft cover
designed to block the heat generated by slowing from the probe's arrival
speed of about 115,000 miles per hour to subsonic speed in less than 2
minutes. After the covers are released, the descent module deploys its
8-foot parachute and its instruments, the control and data system, and
the radio-relay transmitter go to work.
Operating at 128 bits per second, the dual L-band transmitters send
nearly identical streams of scientific data to the orbiter. The probe's
relay radio aboard the orbiter will have two redundant receivers that
process probe science data, plus radio science and engineering data for
transmission to the orbiter communications system. Minimum received
signal strength is 31 dBm. The receivers also measure signal strength and
Doppler shift as part of the experiments for measuring wind speeds and
atmospheric absorption of radio signals.
Probe electronics are powered by long-life, high-discharge-rate
34-volt lithium batteries, which remain dormant for more than 5 years
during the journey to Jupiter. The batteries have an estimated capacity of
about 18 amp-hours on arrival at Jupiter.
Orbiter Scientific Activities
The orbiter, in addition to delivering the probe to Jupiter and relaying
probe data to Earth, will support all the scientific investigations of
Venus, the Earth and moon, asteroids and the interplanetary medium,
Jupiter's satellites and magnetosphere, and observation of the giant
planet itself.
The orbiter weighs about 5,200 pounds including about 2,400 pounds of
rocket propellant to be expended in some 30 relatively small maneuvers
during the long gravity-assisted flight to Jupiter, the large thrust
maneuver which puts the craft into its Jupiter orbit, and the 30 or so trim
maneuvers planned for the satellite tour phase.
The retropropulsion module consists of 12 10-newton thrusters, a
single 400-newton engine, and the fuel, oxidizer, and pressurizing-gas
tanks, tubing, valves and control equipment. (A thrust of 10 newtons
would support a weight of about 2.2 pounds at Earth's surface). The
propulsion system was developed and built by
Messerschmitt-Bolkow-Blohm and provided by the Federal Republic of
Germany.
The orbiter's maximum communications rate is 134 kilobits per second
(the equivalent of about one black-and-white image per minute); there are
other data rates, down to 10 bits per second, for transmitting engineering
data under poor conditions. The spacecraft transmitters operate at
S-band and X-band (2295 and 8415 megahertz) frequencies between Earth
and on L-band between the probe.
The high-gain antenna is a 16-foot umbrella-like reflector unfurled
after the first Earth flyby. Two low-gain antennas (one pointed forward
and one aft, both mounted on the spinning section) are provided to support
communications during the Earth-Venus-Earth leg of the flight and
whenever the main antenna is not deployed and pointed at Earth. The
despun section of the orbiter carries a radio relay antenna for receiving
the probe's data transmissions.
Electrical power is provided to Galileo's equipment by two radioisotope
thermoelectric generators. Heat produced by natural radioactive decay of
plutonium 238 dioxide is converted to approximately 500 watts of
electricity (570 watts at launch, 480 at the end of the mission) to operate
the orbiter equipment for its 8-year active period. This is the same type
of power source used by the Voyager and Pioneer Jupiter spacecraft in
their long outer-planet missions, by the Viking lander spacecraft on Mars
and the lunar scientific packages left on the Moon.
Most spacecraft are stabilized in flight either by spinning around a
major axis or by maintaining a fixed orientation in space, referenced to
the sun and another star. Galileo represents a hybrid of these techniques,
with a spinning section rotating ordinarily at 3 rpm and a "despun" section
which is counter-rotated to provide a fixed orientation for cameras and
other remote sensors.
Instruments that measure fields and particles, together with the main
antenna, the power supply, the propulsion module, most of the computers
and control electronics, are mounted on the spinning section. The
instruments include magnetometer sensors mounted on a 36-foot boom to
escape interference from the spacecraft; a plasma instrument detecting
low-energy charged particles and a plasma-wave detector to study waves
generated in planetary magnetospheres and by lightning discharges; a
high-energy particle detector; and a detector of cosmic and Jovian dust.
The despun section carries instruments and other equipment whose
operation depends on a fixed orientation in space. The instruments include
the camera system; the near-infrared mapping spectrometer to make
multispectral images for atmosphere and surface chemical analysis; the
ultraviolet spectrometer to study gases and ionized gases; and the
photopolarimeter radiometer to measure radiant and reflected energy. The
camera system is expected to obtain images of Jupiter's satellites at
resolutions from 20 to 1,000 times better than Voyager's best.
This section also carries a dish antenna to track the probe in Jupiter's
atmosphere and pick up its signals for relay to Earth. The probe is carried
on the despun section, and before it is released, the whole spacecraft is
spun up briefly to 10 rpm in order to spin-stabilize the probe.
The Galileo spacecraft will carry out its complex operations, including
maneuvers, scientific observations and communications, in response to
stored sequences which are interpreted and executed by various on-board
computers. These sequences are sent up to the orbiter periodically
through the Deep Space Network in the form of command loads.
GROUND SYSTEMS
Galileo communicates with Earth via NASA's Deep Space Network
(DSN), which has a complex of large antennas with receivers and
transmitters located in the California desert, another in Australia and a
third in Spain, linked to a network control center at NASAUs Jet Propulsion
Laboratory in Pasadena, Calif. The spacecraft receives commands, sends
science and engineering data, and is tracked by Doppler and ranging
measurements through this network.
At JPL, about 275 scientists, engineers and technicians, will be
supporting the mission at launch, increasing to nearly 400 for Jupiter
operations including support from the German retropropulsion team at
their control center in the FGR. Their responsibilities include spacecraft
command, interpreting engineering and scientific data from Galileo to
understand its performance, and analyzing navigation data from the DSN.
The controllers use a set of complex computer programs to help them
control the spacecraft and interpret the data.
Because the time delay in radio signals from Earth to Jupiter and back
is more than an hour, the Galileo spacecraft was designed to operate from
programs sent to it in advance and stored in spacecraft memory. A single
master sequence program can cover 4 weeks of quiet operations between
planetary and satellite encounters. During busy Jupiter operations, one
program covers only a few days. Actual spacecraft tasks are carried out
by several subsystems and scientific instruments, many of which work
from their own computers controlled by the main sequence.
Designing these sequences is a complex process balancing the desire to
make certain scientific observations with the need to safeguard the
spacecraft and mission. The sequence design process itself is supported
by software programs, for example, which display to the scientist maps of
the instrument coverage on the surface of an approaching satellite for a
given spacecraft orientation and trajectory. Notwithstanding these aids,
a typical 3-day satellite encounter may take efforts spread over many
months to design, check and recheck. The controllers also use software
designed to check the command sequence further against flight rules and
constraints.
The spacecraft regularly reports its status and health through an
extensive set of engineering measurements. Interpreting these data into
trends and averting or working around equipment failures is a major task
for the mission operations team. Conclusions from this activity become
an important input, along with scientific plans, to the sequence design
process. This too is supported by computer programs written and used in
the mission support area.
Navigation is the process of estimating, from radio range and Doppler
measurements, the position and velocity of the spacecraft to predict its
flight path and design course-correcting maneuvers. These calculations
must be done with computer support. The Galileo mission, with its
complex gravity-assist flight to Jupiter and 10 gravity-assist satellite
encounters in the Jovian system, is extremely dependent on consistently
accurate navigation.
In addition to the programs that directly operate the spacecraft and
are periodically transmitted to it, the mission operations team uses
software amounting to 650,000 lines of programming code in the sequence
design process; 1,615,000 lines in the telemetry interpretation; and
550,000 lines of code in navigation. These must all be written, checked,
tested, used in mission simulations and, in many cases, revised before the
mission can begin.
Science investigators are located at JPL or other university laboratories
and linked by computers. From any of these locations, the scientists can
be involved in developing the sequences affecting their experiments and,
in some cases, in helping to change preplanned sequences to follow up on
unexpected discoveries with second looks and confirming observations.
JUPITER'S SYSTEM
Jupiter is the largest and fastest-spinning planet in the solar system.
Its radius is more than 11 times Earth's, and its mass is 318 times that of
our planet. Named for the chief of the Roman gods, Jupiter contains more
mass than all the other planets combined. It is made mostly of light
elements, principally hydrogen and helium. Its atmosphere and clouds are
deep and dense, and a significant amount of energy is emitted from its
interior.
The earliest Earth-based telescopic observations showed bands and
spots in Jupiter's atmosphere. One storm system, the Red Spot, has been
seen to persist over three centuries.
Atmospheric forms and dynamics were observed in increasing detail
with the Pioneer and Voyager flyby spacecraft, and Earth-based infrared
astronomers have recently studied the nature and vertical dynamics of
deeper clouds.
Sixteen satellites are known. The four largest, discovered by the
Italian scientist Galileo Galilei in 1610, are the size of small planets.
The innermost of these, Io, has active sulfurous volcanoes, discovered by
Voyager 1 and further observed by Voyager 2 and Earth-based infrared
astronomy. Io and Europa are about the size and density of Earth's moon (3
to 4 times the density of water) and probably rocky inside. Ganymede and
Callisto, further out from Jupiter, are the size of Mercury but less than
twice as dense as water. Their cratered surfaces look icy in Voyager
images, and they may be composed partly of ice or water.
Of the other satellites, eight (probably captured asteroids) orbit
irregularly far from the planet, and four (three discovered by the Voyager
mission in 1979) are close to the planet. Voyager also discovered a thin
ring system at Jupiter in 1979.
Jupiter has the strongest planetary magnetic field known. The
resulting magnetosphere is a huge teardrop-shaped, plasma-filled cavity
in the solar wind pointing away from the sun. JupiterUs magnetosphere is
the largest single entity in our solar system, measuring more than 14
times the diameter of the sun. The inner part of the magnetic field is
doughnut- shaped, but farther out it flattens into a disk. The magnetic
poles are offset and tilted relative to Jupiter's axis of rotation, so the
field appears to wobble with Jupiter's rotation (just under 10 hours),
sweeping up and down across the inner satellites and making waves
throughout the magnetosphere.
WHY JUPITER INVESTIGATIONS ARE IMPORTANT
With a thin skin of turbulent winds and brilliant, swift-moving clouds,
the huge sphere of Jupiter is a vast sea of liquid hydrogen and helium.
Jupiter's composition (about 88 percent hydrogen and 11 percent helium
with small amounts of methane, ammonia and water) is thought to
resemble the makeup of the solar nebula, the cloud of gas and dust from
which the sun and planets formed. Scientists believe Jupiter holds
important clues to conditions in the early solar system and the process of
planet formation.
Jupiter may also provide insights into the formation of the universe
itself. Since it resembles the interstellar gas and dust that are thought
to have been created in the "Big Bang," studies of Jupiter may help
scientists calibrate models of the beginning of the universe.
Though starlike in composition, Jupiter is too small to generate
temperatures high enough to ignite nuclear fusion, the process that
powers the stars. Some scientists believe that the sun and Jupiter began
as unequal partners in a binary star system. (If a double star system had
developed, it is unlikely life could have arisen in the solar system.) While
in a sense a "failed star," Jupiter is almost as large as a planet can be. If
it contained more mass, it would not have grown larger, but would have
shrunk from compression by its own gravity. If it were 100 times more
massive, thermonuclear reactions would ignite, and Jupiter would be a
star.
For a brief period after its formation, Jupiter was much hotter, more
luminous, and about 10 times larger than it is now, scientists believe.
Soon after accretion (the condensation of a gas and dust cloud into a
planet), its brightness dropped from about one percent of the Sun's to
about one billionth -- a decline of ten million times.
In its present state Jupiter emits about twice as much heat as it
receives from the Sun. The loss of this heat -- residual energy left over
from the compressive heat of accretion -- means that Jupiter is cooling
and losing energy at a tremendously rapid rate. Temperatures in Jupiter's
core, which were about 90,000 degrees Fahrenheit in the planet's hot,
early phase, are now about 54,000 degrees Fahrenheit, 100 times hotter
than any terrestrial surface, but 500 times cooler than the temperature at
the center of the sun. Temperatures on Jupiter now range from 54,000
degrees Fahrenheit at the core to minus 248 degrees Fahrenheit at the top
of the cloud banks.
Mainly uniform in composition, Jupiter's structure is determined by
gradations in temperature and pressure. Deep in Jupiter's interior there is
thought to be a small rocky core, comprising about four percent of the
planet's mass. This "small" core (about the size of 10 Earths) is
surrounded by a 25,000-mile-thick layer of liquid metallic hydrogen.
(Metallic hydrogen is liquid, but sufficiently compressed to behave as
metal.) Motions of this liquid "metal" are the source of the planet's
enormous magnetic field. This field is created by the same dynamo effect
found in the metallic cores of Earth and other planets.
At the outer limit of the metallic hydrogen layer, pressures equal three
million times that of Earth's atmosphere and the temperature has cooled
to 19,000 degrees Fahrenheit.
Surrounding the central metallic hydrogen region is an outer shell of
"liquid" molecular hydrogen. Huge pressures compress Jupiter's gaseous
hydrogen until, at this level, it behaves like a liquid. The liquid hydrogen
layer extends upward for about 15,000 miles. Then it gradually becomes
gaseous. This transition region between liquid and gas marks, in a sense,
where the solid and liquid planet ends and its atmosphere begins.
From here, Jupiter's atmosphere extends up for 600 more miles, but
only in the top 50 miles are found the brilliant bands of clouds for which
Jupiter is known. The tops of these bands are colored bright yellow, red
and orange from traces of phosphorous and sulfur. Five or six of these
bands, counterflowing east and west, encircle the planet in each
hemisphere. At one point near Jupiter's equator, east winds of 220 mph
blow right next to west winds of 110 mph. At boundaries of these bands,
rapid changes in wind speed and direction create large areas of turbulence
and shear. These are the same forces that create tornados here on Earth.
On Jupiter, these "baroclinic instabilities" are major phenomena, creating
chaotic, swirling winds and spiral features such as White Ovals.
The brightest cloud banks, known as zones, are believed to be higher,
cooler areas where gases are ascending. The darker bands, called belts,
are thought to be warmer, cloudier regions of descent.
The top cloud layer consists of white cirrus clouds of ammonia
crystals, at a pressure six-tenths that of Earth's atmosphere at sea level
(.6 bar). Beneath this layer, at a pressure of about two Earth atmospheres
(2 bars) and a temperature of near minus 160 degrees Fahrenheit, a
reddish-brown cloud of ammonium hydrosulfide is predicted.
At a pressure of about 6 bars, there are believed to be clouds of water
and ice. However, recent Earth-based spectroscopic studies suggest that
there may be less water on Jupiter than expected. While scientists
previously believed Jupiter and the sun would have similar proportions of
water, recent work indicates there may be 100 times less water on
Jupiter than if it had a solar mixture of elements. If this is the case,
there may be only a thin layer of water-ice at the 6 bar level.
However, Jupiter's cloud structure, except for the highest layer of
ammonia crystals, remains uncertain. The height of the lower clouds is
still theoretical -- clouds are predicted to lie at the temperature levels
where their assumed constituents are expected to condense. The Galileo
probe will make the first direct observations of Jupiter's lower
atmosphere and clouds, providing crucial information.
The forces driving Jupiter's fast-moving winds are not well understood
yet. The classical explanation holds that strong currents are created by
convection of heat from Jupiter's hot interior to the cooler polar regions,
much as winds and ocean currents are driven on Earth, from equator to
poles. But temperature differences do not fully explain wind velocities
that can reach 265 mph. An alternative theory is that pressure
differences, due to changes in the thermodynamic state of hydrogen at
high and low temperatures, set up the wind jets.
Jupiter's rapid rotation rate is thought to have effects on wind
velocity and to produce some of Jupiter's bizarre circulation patterns,
including many spiral features. These rotational effects are known as
manifestations of the Coriolis force. Coriolis force is what determines
the spin direction of weather systems. It basically means that on the
surface of a sphere (a planet), a parcel of gas farther from the poles has a
higher rotational velocity around the planet than a parcel closer to the
poles. As gases then move north or south, interacting parcels with
different velocities produce vortices (whirlpools). This may account for
some of Jupiter's circular surface features.
Jupiter spins faster than any planet in the solar system. Though 11 times
Earth's diameter, Jupiter spins more than twice as fast (once in 10 hours),
giving gases on the surface extremely high rates of travel -- 22,000 mph
at the equator, compared with 1000 mph for air at Earth's equator.
Jupiter's rapid spin also causes this gas and liquid planet to flatten
markedly at the poles and bulge at the equator.
Visible at the top of Jupiter's atmosphere are eye-catching features
such as the famous Great Red Spot and the exotic White Ovals, Brown
Barges and White Plumes. The Great Red Spot, which is 25,000 miles wide
and large enough to swallow three Earths, is an enormous oval eddy of
swirling gases. It is driven by two counter-flowing jet streams, which
pass, one on each side of it, moving in opposite directions, each with
speeds of 100-200 mph. The Great Red Spot was first discovered in 1664,
by the British scientist Roger Hook, using Galileo's telescope. In the three
centuries since, the huge vortex has remained constant in latitude in
Jupiter's southern equatorial belt. Because of its stable position,
astronomers once thought it might be a volcano.
Another past theory compared the Great Red Spot to a gigantic
hurricane. However, the GRS rotates anti-cyclonically while hurricanes
are cyclonic features (counterclockwise in the northern hemisphere,
clockwise in the southern) -- and the dynamics of the Great Red Spot
appear unrelated to moisture.
The Great Red Spot most closely resembles an enormous tornado, a huge
vortex that sucks in smaller vortices. The Coriolis effect created by
Jupiter's fast spin, appears to be the key to the dynamics that drive the
spot.
The source of the Great Red Spot's color remains a mystery. Many
scientists now believe it to be caused by phosphorus, but its spectral line
does not quite match that of phosphorus. The GRS may be the largest in a
whole array of spiral phenomena with similar dynamics. About a dozen
white ovals, circulation patterns resembling the GRS, exist in the
southern latitudes of Jupiter and appear to be driven by the same forces.
Scientists do not know why these ovals are white.
Scientists believe the brown barges, which appear like dark patches on
the planet, are holes in the upper clouds, through which the reddish-brown
lower cloud layer may be glimpsed. The equatorial plumes, or white
plumes, may be a type of wispy cirrus anvil cloud.
SPACECRAFT CHARACTERISTICS
Orbiter Probe
Mass,lbs. 5,242 744
Propellant, lbs. 2,400 none
Height (in-flight) 15 feet 34 inches
Inflight span 30 feet
(w/oboom)
Instrument payload 10 instruments 6 instruments
Payload mass, lbs. 260 66
Electric power, watts 570-480 730
(RTGs) (Lithium-sulfur battery)
GALILEO MANAGEMENT
The Galileo Project is managed for NASA's Office of Space Science and
Applications by the NASA Jet Propulsion Laboratory, Pasadena, Calif. This
responsibility includes designing, building, testing, operating and tracking
Galileo. NASA's Ames Research Center, Moffett Field, Calif. is responsible
for the atmosphere probe, which was built by Hughes Aircraft Company, El
Segundo, Calif.
The probe project and science teams will be stationed at Ames during
pre-mission, mission operations, and data reduction periods. Team
members will be at Jet Propulsion Laboratory for probe entry.
The Federal Republic of Germany has furnished the orbiter's
retropropulsion module and is participating in the scientific
investigations. The radioisotope thermoelectric generators were designed
and built for the U.S. Department of Energy by the General Electric
Company.
GALILEO ORBITER AND PROBE SCIENTIFIC INVESTIGATIONS
Listed by experiment/instrument and including the Principal Investigator
and scientific objectives of that investigation:
PROBE
Atmospheric Structure; A. Seiff, NASA's Ames Research Center;
temperature, pressure, density, molecular weight profiles;
Neutral Mass Spectrometer; H. Niemann, NASA's Goddard Space Flight
Center; chemical composition
Helium Abundance; U. von Zahn, Bonn University, FRG; helium/hydrogen
ratio
Nephelometer; B. Ragent, NASA's Ames Research Center; clouds,
solid/liquid particles
Net Flux Radiometer; L. Sromovsky, University of Wisconsin-Madison;
thermal/solar energy profiles
Lightning/Energetic Particles; L. Lanzerotti, Bell Laboratories; detect
lightning, measuring energetic particles
ORBITER (DESPUN PLATFORM)
Solid-State Imaging Camera; M. Belton, National Optical Astronomy
Observatories (Team Leader); Galilean satellites at 1-km resolution or
better
Near-Infrared Mapping Spectrometer; R. Carlson, NASA's Jet Propulsion
Laboratory; surface/atmospheric composition, thermal mapping
Ultraviolet Spectrometer; C. Hord, University of Colorado; atmospheric
gases, aerosols
Photopolarimeter Radiometer; J. Hansen, Goddard Institute for Space
Studies; atmospheric particles, thermal/reflected radiation
ORBITER (SPINNING SPACECRAFT SECTION)
Magnetometer; M. Kivelson, University of California at Los Angeles;
strength and fluctuations of magnetic fields
Energetic Particles; D. Williams, Johns Hopkins Applied Physics
Laboratory; electrons, protons, heavy ions in magnetosphere and
interplanetary space
Plasma; L. Frank, University of Iowa; composition, energy, distribution of
magnetospheric ions
Plasma Wave; D. Gurnett, University of Iowa; electromagnetic waves and
wave-particle interactions
Dust; E. Grun, Max Planck Institute; mass, velocity, charge of submicron
particles
Radio Science - Celestial Mechanics; J. Anderson, JPL (Team Leader);
masses and motions of bodies from spacecraft tracking;
Radio Science - Propagation; H. T. Howard, Stanford University; satellite
radii, atmospheric structure both from radio propagation
INTERDISCIPLINARY INVESTIGATORS
F. P. Fanale; University of Hawaii
P. Gierasch; Cornell University
D. M. Hunten; University of Arizona
A. P. Ingersoll; California Institute of Technology
H. Masursky; U. S. Geological Survey
D. Morrison; Ames Research Center
M. McElroy; Harvard University
G. S. Orton; NASA's Jet Propulsion Laboratory
T. Owen; State University of New York, Stonybrook
J. B. Pollack; NASA's Ames Research Center
C. T Russell; University of California at Los Angeles
C. Sagan; Cornell University
G. Schubert; University of California at Los Angeles
J. Van Allen; University of Iowa
STS-34 INERTIAL UPPER STAGE (IUS-19)
The Inertial Upper Stage (IUS) will again be used with the Space
Shuttle, this time to transport NASA's Galileo spacecraft out of Earth's
orbit to Jupiter, a 2.5-billion-mile journey.
The IUS has been used previously to place three Tracking and Data
Relay Satellites in geostationary orbit as well as to inject the Magellan
spacecraft into its interplanetary trajectory to Venus. In addition, the
IUS has been selected by the agency for the Ulysses solar polar orbit
mission.
After 2 1/2 years of competition, Boeing Aerospace Co., Seattle, was
selected in August 1976 to begin preliminary design of the IUS. The IUS
was developed and built under contract to the Air Force Systems
Command's Space Systems Division. The Space Systems Division is
executive agent for all Department of Defense activities pertaining to the
Space Shuttle system. NASA, through the Marshall Space Flight Center,
Huntsville, Ala., purchases the IUS through the Air Force and manages the
integration activities of the upper stage to NASA spacecraft.
Specifications
IUS-19, to be used on mission STS-34, is a two-stage vehicle weighing
approximately 32,500 lbs. Each stage has a solid rocket motor (SRM),
preferred over liquid-fueled engines because of SRM's relative simplicity,
high reliability, low cost and safety.
The IUS is 17 ft. long and 9.25 ft. in diameter. It consists of an aft
skirt, an aft stage SRM generating approximately 42,000 lbs. of thrust, an
interstage, a forward-stage SRM generating approximately 18,000 lbs. of
thrust, and an equipment support section.
Airborne Support Equipment
The IUS Airborne Support Equipment (ASE) is the mechanical, avionics
and structural equipment located in the orbiter. The ASE supports the IUS
and the Galileo in the orbiter payload bay and elevates the combination for
final checkout and deployment from the orbiter.
The IUS ASE consists of the structure, electromechanical mechanisms,
batteries, electronics and cabling to support the Galileo/IUS. These ASE
subsystems enable the deployment of the combined vehicle; provide,
distribute and/or control electrical power to the IUS and spacecraft;
provide plumbing to cool the radioisotope thermoelectric generator (RTG)
aboard Galileo; and serve as communication paths between the IUS and/or
spacecraft and the orbiter.
IUS Structure
The IUS structure is capable of supporting loads generated internally
and also by the cantilevered spacecraft during orbiter operations and the
IUS free flight. It is made of aluminum skin-stringer construction, with
longerons and ring frames.
Equipment Support Section
The top of the equipment support section contains the spacecraft
interface mounting ring and electrical interface connector segment for
mating and integrating the spacecraft with the IUS. Thermal isolation is
provided by a multilayer insulation blanket across the interface between
the IUS and Galileo.
The equipment support section also contains the avionics which
provide guidance, navigation, control, telemetry, command and data
management, reaction control and electrical power. All mission-critical
components of the avionics system, along with thrust vector actuators,
reaction control thrusters, motor igniter and pyrotechnic stage separation
equipment are redundant to assure reliability of better than 98 percent.
IUS Avionics Subsystems
The avionics subsystems consist of the telemetry, tracking and
command subsystems; guidance and navigation subsystem; data
management; thrust vector control; and electrical power subsystems.
These subsystems include all the electronic and electrical hardware used
to perform all computations, signal conditioning, data processing and
formatting associated with navigation, guidance, control, data and
redundancy management. The IUS avionics subsystems also provide the
equipment for communications between the orbiter and ground stations as
well as electrical power distribution.
Attitude control in response to guidance commands is provided by
thrust vectoring during powered flight and by reaction control thrusters
while coasting. Attitude is compared with guidance commands to
generate error signals. During solid motor firing, these commands gimble
the IUS's movable nozzle to provide the desired pitch and yaw control. The
IUS's roll axis thrusters maintain roll control. While coasting, the error
signals are processed in the computer to generate thruster commands to
maintain the vehicle's altitude or to maneuver the vehicle.
The IUS electrical power subsystem consists of avionics batteries, IUS
power distribution units, a power transfer unit, utility batteries, a
pyrotechnic switching unit, an IUS wiring harness and umbilical and
staging connectors. The IUS avionics system provides 5-volt electrical
power to the Galileo/IUS interface connector for use by the spacecraft
telemetry system.
IUS Solid Rocket Motors
The IUS two-stage vehicle uses a large solid rocket motor and a small
solid rocket motor. These motors employ movable nozzles for thrust
vector control. The nozzles provide up to 4 degrees of steering on the
large motor and 7 degrees on the small motor. The large motor is the
longest-thrusting duration SRM ever developed for space, with the
capability to thrust as long as 150 seconds. Mission requirements and
constraints (such as weight) can be met by tailoring the amount of
propellant carried. The IUS-19 first-stage motor will carry 21,488 lb. of
propellant; the second stage 6,067 lb.
Reaction Control System
The reaction control system controls the Galileo/IUS spacecraft attitude
during coasting, roll control during SRM thrustings, velocity impulses for
accurate orbit injection and the final collision-avoidance maneuver after
separation from the Galileo spacecraft.
As a minimum, the IUS includes one reaction control fuel tank with a
capacity of 120 lb. of hydrazine. Production options are available to add a
second or third tank. However, IUS-19 will require only one tank.
IUS To Spacecraft Interfaces
Galileo is physically attached to the IUS at eight attachment points,
providing substantial load-carrying capability while minimizing the
transfer of heat across the connecting points. Power, command and data
transmission between the two are provided by several IUS interface
connectors. In addition, the IUS provides a multilayer insulation blanket
of aluminized Kapton with polyester net spacers across the Galileo/IUS
interface, along with an aluminized Beta cloth outer layer. All IUS
thermal blankets are vented toward and into the IUS cavity, which in turn
is vented to the orbiter payload bay. There is no gas flow between the
spacecraft and the IUS. The thermal blankets are grounded to the IUS
structure to prevent electrostatic charge buildup.
Flight Sequence
After the orbiter payload bay doors are opened in orbit, the orbiter will
maintain a preselected attitude to keep the payload within thermal
requirements and constraints.
On-orbit predeployment checkout begins, followed by an IUS command link
check and spacecraft communications command check. Orbiter trim
maneuvers are normally performed at this time.
Forward payload restraints will be released and the aft frame of the
airborne-support equipment will tilt the Galileo/IUS to 29 degrees. This
will extend the payload into space just outside the orbiter payload bay,
allowing direct communication with Earth during systems checkout. The
orbiter then will be maneuvered to the deployment attitude. If a problem
has developed within the spacecraft or IUS, the IUS and its payload can be
restowed.
Prior to deployment, the spacecraft electrical power source will be
switched from orbiter power to IUS internal power by the orbiter flight
crew. After verifying that the spacecraft is on IUS internal power and
that all Galileo/IUS predeployment operations have been successfully
completed, a GO/NO-GO decision for deployment will be sent to the crew
from ground support.
When the orbiter flight crew is given a "Go" decision, they will
activate the ordnance that separates the spacecraft's umbilical cables.
The crew then will command the electromechanical tilt actuator to raise
the tilt table to a 58-degree deployment position. The orbiter's RCS
thrusters will be inhibited and an ordnance-separation device initiated to
physically separate the IUS/spacecraft combination from the tilt table.
Six hours, 20 minutes into the mission, compressed springs provide the
force to jettison the IUS/Galileo from the orbiter payload bay at
approximately 6 inches per second. The deployment is normally performed
in the shadow of the orbiter or in Earth eclipse.
The tilt table then will be lowered to minus 6 degrees after IUS and its
spacecraft are deployed. A small orbiter maneuver is made to back away
from IUS/Galileo. Approximately 15 minutes after deployment, the
orbiter's OMS engines will be ignited to move the orbiter away from its
released payload.
After deployment, the IUS/Galileo is controlled by the IUS onboard
computers. Approximately 10 minutes after IUS/Galileo deployment from
the orbiter, the IUS onboard computer will send out signals used by the
IUS and/or Galileo to begin mission sequence events. This signal will also
enable the IUS reaction control system. All subsequent operations will be
sequenced by the IUS computer, from transfer orbit injection through
spacecraft separation and IUS deactivation.
After the RCS has been activated, the IUS will maneuver to the
required thermal attitude and perform any required spacecraft thermal
control maneuvers.
At approximately 45 minutes after deployment from the orbiter,
the ordnance inhibits for the first SRM will be removed. The belly of
the orbiter already will have been oriented towards the IUS/Galileo to
protect orbiter windows from the IUS's plume. The IUS will recompute
the first ignition time and maneuvers necessary to attain the proper
attitude for the first thrusting period. When the proper transfer
orbit opportunity is reached, the IUS computer will send the signal to
ignite the first stage motor 60 minutes after deployment. After
firing approximately 150 seconds, the IUS first stage will have
expended its propellant and will be separated from the IUS second stage.
Approximately 140 seconds after first-stage burnout, the second-
stage motor will be ignited, thrusting about 108 seconds. The IUS second
stage then will separate and perform a final collision/contamination
avoidance maneuver before deactivating.
SHUTTLE SOLAR BACKSCATTER ULTRAVIOLET INSTRUMENT
The Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument was
developed by NASA to calibrate similar ozone measuring space-based
instruments on the National Oceanic and Atmospheric Administration's
TIROS satellites (NOAA-9 and -11).
The SSBUV will help scientists solve the problem of data reliability
caused by calibration drift of solar backscatter ultraviolet (SBUV)
instruments on orbiting spacecraft. The SSBUV uses the Space Shuttle's
orbital flight path to assess instrument performance by directly
comparing data from identical instruments aboard the TIROS spacecraft,
as the Shuttle and the satellite pass over the same Earth location within a
1-hour window. These orbital coincidences can occur 17 times per day.
The SBUV measures the amount and height distribution of ozone in the
upper atmosphere. It does this by measuring incident solar ultraviolet
radiation and ultraviolet radiation backscattered from the Earth's
atmosphere. The SBUV measures these parameters in 12 discrete
wavelength channels in the ultraviolet. Because ozone absorbs in the
ultraviolet, an ozone measurement can be derived from the ratio of
backscatter radiation at different wavelengths, providing an index of the
vertical distribution of ozone in the atmosphere.
Global concern over the depletion of the ozone layer has sparked
increased emphasis on developing and improving ozone measurement
methods and instruments. Accurate, reliable measurements from space
are critical to the detection of ozone trends and for assessing the
potential effects and development of corrective measures.
The SSBUV missions are so important to the support of Earth science
that six additional missions have been added to the Shuttle manifest for
calibrating ozone instruments on future TIROS satellites. In addition, the
dates of the four previously manifested SSBUV flights have been
accelerated.
The SSBUV instrument and its dedicated electronics, power, data and
command systems are mounted in the Shuttle's payload bay in two Get
Away Special canisters, an instrument canister and a support canister.
Together, they weigh approximately 1200 lb. The instrument canister
holds the SSBUV, its specially designed aspect sensors and in-flight
calibration system. A motorized door assembly opens the canister to
allow the SSBUV to view the sun and Earth and closes during the in-flight
calibration sequence.
The support canister contains the power system, data storage and
command decoders. The dedicated power system can operate the SSBUV
for a total of approximately 40 hours.
The SSBUV is managed by NASA's Goddard Space Flight Center,
Greenbelt, Md. Ernest Hilsenrath is the principal investigator.
GROWTH HORMONE CONCENTRATIONS AND DISTRIBUTION IN PLANTS
The Growth Hormone Concentration and Distribution in Plants (GHCD)
experiment is designed to determine the effects of microgravity on the
concentration, turnover properties, and behavior of the plant growth
hormone, Auxin, in corn shoot tissue (Zea Mays).
Mounted in foam blocks inside two standard middeck lockers, the
equipment consists of four plant cannisters, two gaseous nitrogen
freezers and two temperature recorders. Equipment for the experiment,
excluding the lockers, weighs 97.5 pounds.
A total of 228 specimens (Zea Mays seeds) are "planted" in special
filter, paper-Teflon tube holders no more than 56 hours prior to flight.
The seeds remain in total darkness throughout the mission.
The GHCD experiment equipment and specimens will be prepared in a
Payload Processing Facility at KSC and placed in the middeck lockers. The
GHCD lockers will be installed in the orbiter middeck within the last 14
hours before launch.
No sooner than 72 hours after launch, mission specialist Ellen Baker
will place two of the plant cannisters into the gaseous nitrogen freezers
to arrest the plant growth and preserve the specimens. The payload will
be restowed in the lockers for the remainder of the mission.
After landing, the payload must be removed from the orbiter within 2
hours and will be returned to customer representatives at the landing site.
The specimens will be examined post flight for microgravity effects.
The GHCD experiment is sponsored by NASA Headquarters, the Johnson
Space Center and Michigan State University.
POLYMER MORPHOLOGY
The Polymer Morphology (PM) experiment is a 3M-developed organic
materials processing experiment designed to explore the effects of
microgravity on polymeric materials as they are processed in space.
Since melt processing is one of the more industrially significant
methods for making products from polymers, it has been chosen for study
in the PM experiment. Key aspects of melt processing include
polymerization, crystallization and phase separation. Each aspect will be
examined in the experiment. The polymeric systems for the first flight of
PM include polyethelyne, nylon-6 and polymer blends.
The apparatus for the experiment includes a Fournier transform
infrared (FTIR) spectrometer, an automatic sample manipulating system
and a process control and data acquisition computer known as the Generic
Electronics Module (GEM). The experiment is contained in two separate,
hermetically sealed containers that are mounted in the middeck of the
orbiter. Each container includes an integral heat exchanger that transfers
heat from the interior of the containers to the orbiter's environment. All
sample materials are kept in triple containers for the safety of the
astronauts.
The PM experiment weighs approximately 200 lb., occupies three
standard middeck locker spaces (6 cubic ft., total) in the orbiter and
requires 240 watts to operate.
Mission specialists Franklin R. Chang-Diaz and Shannon W. Lucid are
responsible for the operation of the PM experiment on orbit. Their
interface with the PM experiment is through a small, NASA-supplied
laptop computer that is used as an input and output device for the main PM
computer. This interface has been programmed by 3M engineers to manage
and display the large quantity of data that is available to the crew. The
astronauts will have an active role in the operation of the experiment.
In the PM experiment, infrared spectra (400 to 5000 cm-1) will be
acquired from the FTIR by the GEM computer once every 3.2 seconds as the
materials are processed on orbit. During the 100 hours of processing
time, approximately 2 gigabytes of data will be collected. Post flight, 3M
scientists will process the data to reveal the effects of microgravity on
the samples processed in space.
The PM experiment is unique among material processing experiments in
that measurements characterizing the effects of microgravity will be
made in real time, as the materials are processed in space.
In most materials processing space experiments, the materials have
been processed in space with little or no measurements made during
on-orbit processing and the effects of microgravity determined post
facto.
The samples of polymeric materials being studied in the PM experiment
are thin films (25 microns or less) approximately 25 mm in diameter. The
samples are mounted between two infrared transparent windows in a
specially designed infrared cell that provides the capability of thermally
processing the samples to 200 degrees Celsius with a high degree of
thermal control. The samples are mounted on a carousel that allows them
to be positioned, one at a time, in the infrared beam where spectra may be
acquired. The GEM provides all carousel and sample cell control. The first
flight of PM will contain 17 samples.
The PM experiment is being conducted by 3M's Space Research and
Applications Laboratory. Dr. Earl L. Cook is 3M's Payload Representative
and Mission Coordinator. Dr. Debra L. Wilfong is PM's Science Coordinator,
and James E. Steffen is the Hardware Coordinator.
The PM experiment, a commercial development payload, is sponsored by
NASA's Office of Commercial Programs. The PM experiment will be 3M's
fifth space experiment and the first under the company's 10-year Joint
Endeavor Agreement with NASA for 62 flight experiment opportunities.
Previous 3M space experiments have studied organic crystal growth from
solution (DMOS/1 on mission STS 51-A and DMOS/2 on STS 61-B) and
organic thin film growth by physical vapor treatment (PVTOS/1 on STS
51-I and PVTOS/2 on mission STS-26).
STUDENT EXPERIMENT
Zero Gravity Growth of Ice Crystals From Supercooled Water With Relation
To Temperature (SE82-15)
This experiment, proposed by Tracy L. Peters, formerly of Ygnacio High
School, Concord, Calif., will observe the geometric ice crystal shapes
formed at supercooled temperatures, below 0 degrees Celsius, without the
influence of gravity.
Liquid water has been discovered at temperatures far below water's
freezing point. This phonomenon occurs because liquid water does not
have a nucleus, or core, around which to form the crystal. When the ice
freezes at supercold temperatures, the ice takes on many geometric
shapes based on the hexagon. The shape of the crystal primarily depends
on the supercooled temperature and saturation of water vapor. The shapes
of crystals vary from simple plates to complex prismatic crystals.
Many scientists have tried to determine the relation between
temperature and geometry, but gravity has deformed crystals, caused
convection currents in temperature-controlled apparatus, and caused
faults in the crystalline structure. These all affect crystal growth by
either rapid fluctuations of temperature or gravitational influence of the
crystal geometry.
The results of this experiment could aid in the design of radiator cooling
and cryogenic systems and in the understanding of high-altitude
meteorology and planetary ring structure theories.
Peters is now studying physics at the University of California at Berkeley.
His teacher advisor is James R. Cobb, Ygnacio High School; his sponsor is
Boeing Aerospace Corp., Seattle.
Peters also was honored as the first four-time NASA award winner at the
International Science and Engineering Fair (ISEF), which recognizes
student's creative scientific endeavors in aerospace research. At the
1982 ISEF, Peters was one of two recipients of the Glen T. Seaborg Nobel
Prize Visit Award, an all-expense-paid visit to Stockholm to attend the
Nobel Prize ceremonies, for his project "Penetration and Diffusion of
Supersonic Fluid."
MESOSCALE LIGHTNING EXPERIMENT
The Space Shuttle will again carry the Mesoscale Lightning Experiment
(MLE), designed to obtain nighttime images of lightning in order to better
understand the global distribution of lightning, the interrelationships
between lightning events in nearby storms, and relationships between
lightning, convective storms and precipitation.
A better understanding of the relationships between lightning and
thunderstorm characteristics can lead to the development of applications
in severe storm warning and forecasting, and early warning systems for
lightning threats to life and property.
In recent years, NASA has used both Space Shuttle missions and
high-altitude U-2 aircraft to observe lightning from above convective
storms. The objectives of these observations have been to determine
some of the baseline design requirements for a satellite-borne optical
lightning mapper sensor; study the overall optical and electrical
characteristics of lightning as viewed from above the cloudtop; and
investigate the relationship between storm electrical development and
the structure, dynamics and evolution of thunderstorms and thunderstorm
systems.
The MLE began as an experiment to demonstrate that meaningful,
qualitative observations of lightning could be made from the Shuttle.
Having accomplished this, the experiment is now focusing on quantitative
measurements of lightning characteristics and observation simulations
for future space-based lightning sensors.
Data from the MLE will provide information for the development of
observation simulations for an upcoming polar platform and Space Station
instrument, the Lightning Imaging Sensor (LIS). The lightning experiment
also will be helpful for designing procedures for using the Lightning
Mapper Sensor (LMS), planned for several geostationary platforms.
In this experiment, Atlantis' payload bay camera will be pointed
directly below the orbiter to observe nighttime lightning in large, or
mesoscale, storm systems to gather global estimates of lightning as
observed from Shuttle altitudes. Scientists on the ground will analyze the
imagery for the frequency of lightning flashes in active storm clouds
within the camera's field of view, the length of lightning discharges, and
cloud brightness when illuminated by the lightning discharge within the
cloud.
If time permits during missions, astronauts also will use a handheld
35mm camera to photograph lightning activity in storm systems not
directly below the Shuttle's orbital track.
Data from the MLE will be associated with ongoing observations of
lightning made at several locations on the ground, including observations
made at facilities at the Marshall Space Flight Center, Huntsville, Ala.;
Kennedy Space Center, Fla.; and the NOAA Severe Storms Laboratory,
Norman, Okla. Other ground-based lightning detection systems in
Australia, South America and Africa will be intergrated when possible.
The MLE is managed by the Marshall Space Flight Center. Otha H. Vaughan
Jr., is coordinating the experiment. Dr. Hugh Christian is the project
scientist, and Dr. James Arnold is the project manager.
IMAX
The IMAX project is a collaboration between NASA and the Smithsonian
Institution's National Air and Space Museum to document significant space
activities using the IMAX film medium. This system, developed by the
IMAX Systems Corp., Toronto, Canada, uses specially designed 70mm film
cameras and projectors to record and display very high definition
large-screen color motion pictures.
IMAX cameras previously have flown on Space Shuttle missions 41-C,
41-D and 41-G to document crew operations in the payload bay and the
orbiter's middeck and flight deck along with spectacular views of space
and Earth.
Film from those missions form the basis for the IMAX production, "The
Dream is Alive." On STS 61-B, an IMAX camera mounted in the payload bay
recorded extravehicular activities in the EAS/ACCESS space construction
demonstrations.
The IMAX camera, most recently carried aboard STS-29, will be used on
this mission to cover the deployment of the Galileo spacecraft and to
gather material on the use of observations of the Earth from space for
future IMAX films.
AIR FORCE MAUI OPTICAL SITE CALIBRATION TEST
The Air Force Maui Optical Site (AMOS) tests allow ground-based
electro-optical sensors located on Mt. Haleakala, Maui, Hawaii, to collect
imagery and signature data of the orbiter during cooperative overflights.
Scientific observations made of the orbiter while performing Reaction
Control System thruster firings, water dumps or payload bay light
activation are used to support the calibration of the AMOS sensors and the
validation of spacecraft contamination models. AMOS tests have no
payload-unique flight hardware and only require that the orbiter be in
predefined attitude operations and lighting conditions.
The AMOS facility was developed by Air Force Systems Command
(AFSC) through its Rome Air Development Center, Griffiss Air Force Base,
N.Y., and is administered and operated by the AVCO Everett Research
Laboratory, Maui. The principal investigator for the AMOS tests on the
Space Shuttle is from AFSC's Air Force Geophysics Laboratory, Hanscom
Air Force Base, Mass. A co-principal investigator is from AVCO.
Flight planning and mission support activities for the AMOS test
opportunities are provided by a detachment of AFSC's Space Systems
Division at Johnson Space Center, Houston. Flight operations are
conducted at JSC Mission Control Center in coordination with the AMOS
facilities located in Hawaii.
SENSOR TECHNOLOGY EXPERIMENT
The Sensor Technology Experiment (STEX) is a radiation detection
experiment designed to measure the natural radiation background. The
STEX is a self-contained experiment with its own power, sensor, computer
control and data storage. A calibration pack, composed of a small number
of passive threshold reaction monitors, is attached to the outside of the
STEX package.
Sponsored by the Strategic Defense Initiative Organization, the STEX
package weighs approximately 50 pounds and is stowed in a standard
middeck locker throughout the flight.
PAYLOAD AND VEHICLE WEIGHTS
Vehicle/Payload Weight (Pounds)
Orbiter (Atlantis) Empty 172,018
Galileo/IUS (payload bay) 43,980
Galileo support hardware (middeck) 59
SSBUV (payload bay) 637
SSBUV support 578
DSO 49
DTO 170
GHCD 130
IMAX 269
MLE 15
PM 219
SSIP 70
STEX 52
Orbiter and Cargo at SRB Ignition 264,775
Total Vehicle at SRB Ignition 4,523,810
Orbiter Landing Weight 195,283
SPACEFLIGHT TRACKING AND DATA NETWORK
Primary communications for most activities on STS-34 will be
conducted through the orbiting Tracking and Data Relay Satellite System
(TDRSS), a constellation of three communications satellites in
geosynchronous orbit 22,300 miles above the Earth. In addition, three
NASA Spaceflight Tracking and Data Network (STDN) ground stations and
the NASA Communications Network (NASCOM), both managed by Goddard
Space Flight Center, Greenbelt, Md., will play key roles in the mission.
Three stations -- Merritt Island and Ponce de Leon, Florida and the
Bermuda -- serve as the primary communications during the launch and
ascent phases of the mission. For the first 80 seconds, all voice,
telemetry and other communications from the Space Shuttle are relayed to
the mission managers at Kennedy and Johnson Space Centers by way of the
Merritt Island facility.
At 80 seconds, the communications are picked up from the Shuttle and
relayed to the two NASA centers from the Ponce de Leon facility, 30 miles
north of the launch pad. This facility provides the communications
between the Shuttle and the centers for 70 seconds, or until 150 seconds
into the mission. This is during a critical period when exhaust from the
solid rocket motors "blocks out" the Merritt Island antennas.
The Merritt Island facility resumes communications to and from the
Shuttle after those 70 seconds and maintains them until 6 minutes, 30
seconds after launch when communications are "switched over" to
Bermuda. Bermuda then provides the communications until 11 minutes
after liftoff when the TDRS-East satellite acquires the Shuttle.
TDRS-West acquires the orbiter at launch plus 50 minutes.
The TDRS-East and -West satellites will provide communications with
the Shuttle during 85 percent or better of each orbit. The TDRS-West
satellite will handle communications with the Shuttle during its descent
and landing phases.
STS-34 CARGO CONFIGURATION (illustration)
CREW BIOGRAPHIES
Donald E. Williams, 47, Capt., USN, will serve as commander. Selected
as an astronaut in January 1978, he was born in Lafayette, Ind.
Williams was pilot for STS-51D, the fourth flight of Discovery,
launched April 12, 1985. During the mission, the seven-member crew
deployed the Anik-C communications satellite for Telesat of Canada and
the Syncom IV-3 satellite for the U.S. Navy. A malfunction in the Syncom
spacecraft resulted in the first unscheduled extravehicular, rendezvous
and proximity operation for the Space Shuttle in an attempt to activate
the satellite.
He graduated from Otterbein High School, Otterbein, Ind., in 1960 and
received his B.S. degree in mechanical engineering from Purdue University
in 1964. Williams completed his flight training at Pensacola, Fla.,
Meridian, Miss., and Kingsville, Texas, and earned his wings in 1966.
During the Vietnam Conflict, Williams completed 330 combat missions.
He has logged more than 5,400 hours flying time, including 5,100 in jets,
and 745 aircraft carrier landings.
Michael J. McCulley, 46, Cdr., USN, will be pilot on this flight. Born in
San Diego, McCulley considers Livingston, Tenn., his hometown. He was
selected as a NASA astronaut in 1984. He is making his first Space
Shuttle flight.
McCulley graduated from Livingston Academy in 1961. He received B.S.
and M.S. degrees in metallurgical engineering from Purdue University in
1970.
After graduating from high school, McCulley enlisted in the U.S. Navy
and subsequently served on one diesel-powered and two nuclear-powered
submarines. Following flight training, he served tours of duty in A-4 and
A-65 aircraft and was selected to attend the Empire Test Pilots School in
Great Britain. He served in a variety of test pilot billets at the Naval Air
Test Center, Patuxent River, Md., before returning to sea duty on the USS
Saratoga and USS Nimitz.
He has flown more than 50 types of aircraft, logging more than 4,760
hours, and has almost 400 carrier landings on six aircraft carriers.
Shannon W. Lucid, 46, will serve as mission specialist (MS-1) on this,
her second Shuttle flight. Born in Shanghai, China, she considers Bethany,
Okla., her hometown. Lucid is a member of the astronaut class of 1978.
Lucid's first Shuttle mission was during STS 51-G, launched from the
Kennedy Space Center on June 17, 1985. During that flight, the crew
deployed communications satellites for Mexico, the Arab League and the
United States.
Lucid graduated from Bethany High School in 1960. She then attended
the University of Oklahoma where she received a B.S. degree in chemistry
in 1963, an M.S. degree in biochemistry in 1970 and a Ph.D. in biochemistry
in 1973.
Before joining NASA, Lucid held a variety of academic assignments
such as teaching assistant at the University of Oklahoma's department of
chemistry; senior laboratory technician at the Oklahoma Medical Research
Foundation; chemist at Kerr-McGee in Oklahoma City; graduate assistant in
the University of Oklahoma Health Science Center's department of
biochemistry; and molecular biology and research associate with the
Oklahoma Medical Research Foundation in Oklahoma City. Lucid also is a
commercial, instrument and multi-engine rated pilot.
Franklin Chang-Diaz, 39, will serve as MS-2. Born in San Jose, Costa
Rica, Chang-Diaz also will be making his second flight since being
selected as an astronaut in 1980.
Chang-Diaz made his first flight aboard Columbia on mission STS 61-C,
launched from KSC Jan. 12, 1986. During the 6-day flight he participated
in the deployment of the SATCOM KU satellite, conducted experiments in
astrophysics and operated the materials science laboratory, MSL-2.
Chang-Diaz graduated from Colegio De La Salle, San Jose, Costa Rica, in
1967, and from Hartford High School, Hartford, Conn., in 1969. He received
a B.S. degree in mechanical engineering from the University of Connecticut
in 1973 and a Ph.D. in applied plasma physics from the Massachusetts
Institute of Technology in 1977.
While attending the University of Connecticut, Chang-Diaz also worked
as a research assistant in the physics department and participated in the
design and construction of high-energy atomic collision experiments.
Upon entering graduate school at MIT, he became heavily involved in the
United State's controlled fusion program and conducted intensive research
in the design and operation of fusion reactors. In 1979, he developed a
novel concept to guide and target fuel pellets in an inertial fusion reactor
chamber. In 1983, he was appointed as visiting scientist with the MIT
Plasma Fusion Center which he visits periodically to continue his research
on advanced plasma rockets.
Chang-Diaz has logged more than 1,500 hours of flight time, including
1,300 hours in jet aircraft.
Ellen S. Baker, 36, will serve as MS-3. She will be making her first
Shuttle flight. Baker was born in Fayetteville, N.C., and was selected as
an astronaut in 1984.
Baker graduated from Bayside High School, New York, N.Y., in 1970. She
received a B.A. degree in geology from the State University of New York at
Buffalo in 1974, and an M.D. from Cornell University in 1978.
After medical school, Baker trained in internal medicine at the
University of Texas Health Science Center in San Antonio, Texas. In 1981,
she was certified by the American Board of Internal Medicine.
Baker joined NASA as a medical officer at the Johnson Space Center in
1981 after completing her residency. That same year, she graduated with
honors from the Air Force Aerospace Medicine Primary Course at Brooks
Air Force Base in San Antonio. Prior to her selection as an astronaut, she
served as a physician in the Flight Medicine Clinic at JSC.
NASA PROGRAM MANAGEMENT
NASA Headquarters
Washington, D.C.
Richard H. Truly
NASA Administrator
James R. Thompson Jr.
NASA Deputy Administrator
William B. Lenoir
Acting Associate Administrator for Space Flight
George W.S. Abbey
Deputy Associate Administrator for Space Flight
Arnold D. Aldrich
Director, National Space Transportation Program
Leonard S. Nicholson
Deputy Director, NSTS Program
(located at Johnson Space Center)
Robert L. Crippen
Deputy Director, NSTS Operations
(located at Kennedy Space Center)
David L. Winterhalter
Director, Systems Engineering and Analyses
Gary E. Krier
Director, Operations Utilization
Joseph B. Mahon
Deputy Associate Administrator
for Space Flight (Flight Systems)
Charles R. Gunn
Director, Unmanned Launch Vehicles
and Upper Stages
George A. Rodney
Associate Administrator for Safety, Reliability,
Maintainability and Quality Assurance
Charles T. Force
Associate Administrator for Operations
Dr. Lennard A. Fisk
Associate Administrator for Space Science
and Applications
Samuel Keller
Assistant Deputy Associate Administrator
NASA Headquarters
Al Diaz
Deputy Associate Administrator for
Space Science and Applications
Dr. Geoffrey A. Briggs
Director, Solar System Exploration Division
Robert F. Murray
Manager, Galileo Program
Dr. Joseph Boyce
Galileo Program Scientist
Johnson Space Center
Houston, Texas
Aaron Cohen
Director
Paul J. Weitz
Deputy Director
Richard A. Colonna
Manager, Orbiter and GFE Projects
Donald R. Puddy
Director, Flight Crew Operations
Eugene F. Kranz
Director, Mission Operations
Henry O. Pohl
Director, Engineering
Charles S. Harlan
Director, Safety, Reliability and Quality Assurance
Kennedy Space Center
Florida
Forrest S. McCartney
Director
Thomas E. Utsman
Deputy Director
Jay F. Honeycutt
Director, Shuttle Management
and Operations
Robert B. Sieck
Launch Director
George T. Sasseen
Shuttle Engineering Director
Conrad G. Nagel
Atlantis Flow Director
James A. Thomas
Director, Safety, Reliability and
Quality Assurance
John T. Conway
Director, Payload Managerment
and Operations
Marshall Space Flight Center
Huntsville, Ala.
Thomas J. Lee
Director
Dr. J. Wayne Littles
Deputy Director
G. Porter Bridwell
Manager, Shuttle Projects Office
Dr. George F. McDonough
Director, Science and Engineering
Alexander A. McCool
Director, Safety, Reliability and Quality Assurance
Royce E. Mitchell
Manager, Solid Rocket Motor Project
Cary H. Rutland
Manager, Solid Rocket Booster Project
Jerry W. Smelser
Manager, Space Shuttle Main Engine Project
G. Porter Bridwell
Acting Manager, External Tank Project
Sidney P. Saucier
Manager, Space Systems Projects Office
[for IUS]
Stennis Space Center
Bay St. Louis, Miss.
Roy S. Estess
Director
Gerald W. Smith
Deputy Director
William F. Taylor
Associate Director
J. Harry Guin
Director, Propulsion Test Operations
Edward L. Tilton III
Director, Science and Technology Laboratory
John L. Gasery Jr.
Chief, Safety/Quality Assurance
and Occupational Health
Jet Propulsion Laboratory
Pasadena, Calif.
Dr. Lew Allen
Director
Dr. Peter T. Lyman
Deputy Director
Gene Giberson
Laboratory Director for Flight Projects
John Casani
Assistant Laboratory Director for Flight Projects
Richard J. Spehalski
Manager, Galileo Project
William J. O'Neil
Manager, Science and Mission Design,
Galileo Project
Dr. Clayne M. Yeates
Deputy Manager, Science and Mission Design,
Galileo Project
Dr. Torrence V Johnson
Galileo Project Scientist
Neal E. Ausman Jr.
Mission Operations and Engineering Manager
Galileo Project
A. Earl Cherniack
Orbiter Spacecraft Manager
Galileo Project
Matthew R. Landano
Deputy Orbiter Spacecraft Manager
Galileo Project
William G. Fawcett
Orbiter Science Payload Manager
Galileo Project
Ames Research Center
Mountain View, Calif.
Dr. Dale L. Compton
Acting Director
Dr. Joseph C. Sharp
Acting Director, Space Research Directorate
Joel Sperans
Chief, Space Exploration Projects Office
Benny Chin
Probe Manager
Galileo Project
Dr. Lawrence Colin
Probe Scientist
Galileo Project
Dr. Richard E. Young
Probe Scientist
Galileo Project
Ames-Dryden Flight Research Facility
Edwards, Calif.
Martin A. Knutson
Site Manager
Theodore G. Ayers
Deputy Site Manager
Thomas C. McMurtry
Chief, Research Aircraft Operations Division
Larry C. Barnett
Chief, Shuttle Support Office
Goddard Space Flight Center
Greenbelt, Md.
Dr. John W. Townsend
Director
Peter Burr
Director, Flight Projects
Dale L. Fahnestock
Director, Mission Operations and Data Systems
Daniel A. Spintman
Chief, Networks Division
Gary A. Morse
Network Director
Dr. Robert D. Hudson
Head, Atmospheric Chemistry and Dynamics
Ernest Hilsenrath
SSBUV Principal Investigator
Jon R. Busse
Director, Engineering Directorate
Robert C. Weaver Jr.
Chief, Special Payloads Division
Neal F. Barthelme
SSBUV Mission Manager
|
| 560.37 | Launch is on but off for mechnical reasons | HYDRA::BIRO | | Wed Oct 11 1989 10:19 | 5 |
| The Judge refused to hear the case to stop the launch,
The Judge said that NASA had meet all EPA rules.
jb
|
| 560.38 | Delay of One Week Possible | SHAOLN::DENSMORE | But I'm feeling muuuch better now! | Wed Oct 11 1989 11:39 | 15 |
| The judge ruled that NASA filed an environmental impact statement with
sufficient information to make a reasonable decision. He said that the
court does not have to decide if the decision to launch was a good one.
The backup controller for the No 2 engine is giving false readings and
there is a chance that it could force an abort during liftoff. Robert Crippen
and other NASA officials decided that it would be better to replace it and
not take a chance. Crippen indicated that it could be a week's delay but
NASA is assessing the actual delay today.
Re some earlier notes: Actually, Dan Rather had some pretty good graphics
on the way that the plutonium is packaged for the spacecraft. One would
tend to side with NASA after the presentation.
Mike
|
| 560.39 | GALILEO Update - October 10 | RENOIR::KLAES | N = R*fgfpneflfifaL | Wed Oct 11 1989 14:07 | 39 |
| Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Galileo Update
Date: 10 Oct 89 21:35:55 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO DAILY REPORT
10 OCTOBER 1989
General
Spacecraft
The spacecraft is in its launch ready state as previously reported.
The spacecraft continues to be monitored 24 hours a day both at
KSC and at Pasadena. There have been no problems to date.
LCET
LCET #1 was returned to the VPF (Vehicle Processing Facility)
area on 9 October. All communications, power, and power cables have
been installed.
LCET #1 is now operational and monitoring the spacecraft
telemetry derived from the composite telemetry through the T-0
cabling. Telemetry alarms matching those of the MTS have been
inserted and are operational. This provides a backup capability
in case the lines to JPL become inoperative.
Schedule Discussion and Assessment
The launch at this time is still scheduled for 12 October at 1:29 p.m. EDT
Ron Baalke (818) 541-2341
Jet Propulsion Lab M/S 301-355
4800 Oak Grove Dr.
Pasadena, CA 91109
|
| 560.40 | STS-34 Update - October 11 | RENOIR::KLAES | N = R*fgfpneflfifaL | Wed Oct 11 1989 18:05 | 56 |
| Newsgroups: sci.space
Subject: NASA Headline News for 10/11/89 (Forwarded)
Date: 11 Oct 89 18:00:16 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
Wednesday, Oct. 11, 1989 Audio: 202/755-1788
-----------------------------------------------------------------
This is NASA Headline News for Wednesday, October 11:
A faulty controller on Atlantis's Main Engine No. 2 has forced
NASA officials to postpone tomorrow's scheduled launch of the Space
Shuttle and its cargo, the Galileo/Jupiter space probe. The problem
with the controller surfaced during routine pre-launch tests when in
several instances a computer bolted to the No. 2 Main Engine generated
faulty data and technicians were unable to duplicate the problem. NASA
officials decided to change out the controller and the work was begun
last night. Robert Crippen, who heads the Shuttle launch management
team, said this morning the changeout work will probably impact the
launch date by about a week, although he said "we're trying to improve
on that." He said a new launch date probably won't be announced for a
couple of days.
The decision to postpone the launch came just an hour after a U.S.
District Court Judge last night had given the go-ahead for the
mission. Judge Oliver Gasch's decision was on a request from three
anti-nuclear and environmental groups who sought to have the launch
stopped on the grounds that plutonium in Galileo's power supply posed
an imminent health risk if an accident should occur. In his ruling,
the judge said, "the public interest weighs heavily against granting a
delay. The Galileo mission is an important part of NASA's solar
system exploration program and will greatly increase our country's
knowledge of space."
The Associated Press reports that a spokesman for one of the
groups who oppose the launch, said last night after the judges ruling,
that protesters plan to follow through with their intention to block
the launch by putting people on the launch pad.
-----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select television. All times are Eastern.
Thursday, Oct. 12.....
11:30 A.M. NASA Update will be transmitted.
All events and times are subject to change without notice.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA
Headquarters, Washington, D.C.
|
| 560.41 | New medical plan for astronauts starting with STS-34 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Oct 12 1989 18:44 | 45 |
| Newsgroups: sci.space
Subject: Private medical consultations to become space flight routine
Date: 12 Oct 89 16:38:06 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
Sarah Keegan
Headquarters, Washington, D.C. October 12, 1989
Pam Alloway
Johnson Space Center, Houston
RELEASE: 89-161
PRIVATE MEDICAL CONSULTATIONS TO BECOME SPACE FLIGHT ROUTINE
Medical consultations between astronauts in space and NASA
physicians on Earth will become a routine part of future Space Shuttle
flights to help improve the understanding and provide timely treatment
of initial space motion sickness symptoms.
A private medical communication will be scheduled between Shuttle
crew members and Mission Control Center flight surgeons during the
pre-sleep periods on the first 2 days of each flight beginning with
STS-34 this month. Additional consultations may be requested by
either the crew or the flight surgeons.
"The communication will assure the most effective treatment of
space motion sickness symptoms during the first 2 days of flight when
the condition is most prevalent," said Dr. Jeff Davis, chief of
Johnson Space Center's Medical Operations Branch.
"While symptoms vary from one person to another," Davis said,
"most cases are mild and constitute little more than an inconvenience
to the crew member. Given the variation in symptoms and available
treatments, we felt it would be useful to plan routine consultations
for the first 2 days of each mission."
The consultations will be confidential because of the
physician-patient relationship and privacy laws. If a crew health
problem is determined to affect a mission adversely, the flight
surgeon will prepare a statement for public release which will address
the nature, gravity and prognosis of the situation. Information
beyond that required to understand mission impact will not be released.
|
| 560.42 | STS-34 Update - October 12 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Oct 12 1989 19:10 | 57 |
| Newsgroups: sci.space
Subject: NASA Headline News for 10/12/89 (Forwarded)
Date: 12 Oct 89 19:16:19 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
Thursday, Oct. 12, 1989 Audio: 202/755-1788
-----------------------------------------------------------------
This is NASA Headline News for Thursday, October 12:
Shuttle engineers and technicians are working towards a launch of
the space shuttle Atlantis and its cargo, the Galileo spacecraft,
during a 24-minute window beginning at 12:57 P.M., Tuesday, October
17. After evaluating the work that will remain after replacing the
number 2 main engine controller on the orbiter, officials estimate
there is a 50-50 chance of completing the work in time to launch on
Tuesday. Managers will make a final decision at about noon on
Saturday whether a Tuesday launch is achievable or whether the launch
will occur on Wednesday, October 18.
Meanwhile, the Washington Post reports a spokesman for the three
groups who oppose the launch because of Galileo's plutonium power
supply, said they would attempt to appeal U.S. District Court Judge
Oliver Gasch's ruling that the launch may proceed. They said they
will ask the Court of Appeals for the District of Columbia to overturn
his decision. The paper reports that because appeals involving
temporary restraining orders are not normally permitted, lawyers for
the groups may first seek an injunction, which is appealable, from
Judge Gasch...and then appeal his expected rejection.
NASA has announced that beginning with next week's STS-34 mission,
medical consultations between astronatus in space and nasa physicians
on the ground will become a routine part of all space shuttle flights
to help improve the understanding and provide timely treatment of
initial space motion sickness symptoms. A private medical
communication will be schedule between shuttle crew members and
mission control center flight surgeons during the pre-sleep periods on
the first 2-days of each flight. Additional consultations may be
requested by either the crew or the flight surgeons.
-----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select television. All times are eastern.
Sunday, Oct. 15.....
Noon STS-34 crew arrival at KSC.
All events and times are subject to change without notice.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA
Headquarters, Washington, D.C.
|
| 560.43 | GALILEO Update - October 11 | RENOIR::KLAES | N = R*fgfpneflfifaL | Fri Oct 13 1989 11:39 | 75 |
| Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Galileo Update
Date: 12 Oct 89 23:14:56 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO DAILY REPORT
11 OCTOBER 1989
SPECIAL ANNOUNCEMENT: 17 October at 12:57 p.m. EDT is the new
launch date for Galileo.
General
Spacecraft
The spacecraft is still in its launch ready state and is being
monitored constantly both at KSC and at Pasadena.
A PF/R was opened, analyzed, and dispositioned on the attachment
of the PRDs (Pressure Release Device) to the RTGs.
LCET
LCETs #1 and #2 are both being manned around the clock when
spacecraft telemetry analysis is in process.
Details
Spacecraft
The spacecraft continues to operate satisfactorily from power
supplied by the RTGs. However, temperature control engineering has
requested that the orbiter air conditioning to the spacecraft be
raised from 52 deg F to 58 deg F. The basis of this request was the
RPM temperature which is at its lower acceptable limit as specified in
the launch commit criteria. The orbiter temperature was raised as per
JPL's request on the evening of 10 October. Appropriate paper is in
process that will allow the inlet temperature to be varied from 48 deg
F to 60 deg F. This in turn will allow for any future adjustment as a
normal operation of the prelaunch activities.
As reported on 9 October, during the mating of the PRD (Pressure
Release Device) to the RTG two additional washers were installed on
each of the four screws used to attach the PRDs to each of the RTGs.
Questions were raised on the action taken, that is, the installation
of the washers. PF/R 54340 was opened to document the concern
expressed by General Electric. Subsequent analysis was made on the
overall incident. The primary points were: 1) that during the
insertion of the screws the engagement of the screws into the insert
locking mechanism was misinterpreted as the screw bottoming out, 2)
two washers were added to reduce the gap which in turn reduced the
amount of screw engagement in the insert locking mechanism, 3) both
JPL and GE engineers agreed that the last one turn into the locking
mechanism was required, 4) the JPL technician, that did the hands-on
work, and the engineer, that witnessed the work, agreed that two screw
turns into the locking element were achieved, 5) that there would be
no impact to the mission if one screw backed out. Additional analysis
was done at JPL, and after review of the total picture, the Project
Manager declared that no further action was necessary; in short, that
the attachment of the PRDs to the RTGs was satisfactory.
Schedule Discussion and Assessment
It was announced this afternoon that the new launch date is 17
October at 12:57 p.m. EDT. The count will be resumed on Monday, 16
October at L-19 hours at 5:57 p.m. EDT. Shortly after the countdown
is picked up the IUS is scheduled to be powered for its final
prelaunch conditioning and checks.
Ron Baalke (818) 541-2341
Jet Propulsion Lab M/S 301-355
4800 Oak Grove Dr.
Pasadena, CA 91109
|
| 560.44 | Who would you trust? | RENOIR::KLAES | N = R*fgfpneflfifaL | Fri Oct 13 1989 11:43 | 58 |
| From: gvg@hpcvlx.cv.hp.com (Greg Goebel)
Newsgroups: sci.space
Subject: Re: Re: Will NASA Contaminate Jupiter?
Date: 12 Oct 89 15:20:03 GMT
Organization: Hewlett-Packard Co., Corvallis, OR, USA
>> The government
>> enjoys federal immunity and in most such cases is "safe" from prosecution.
>
> Give me a break. The judge ruled in favor of Galileo because the NASA
> experts knew what they were talking about and the Christic Luddites didn't.
Right; I wasn't inclined to dismiss the Christics out-of-hand --
if there weren't folks like that around the powers-that-be might get
complacent; and if there was a safety concern, it needed to be
publicly aired -- but the final debate ended up like:
NASA: There are 48 pounds of plutonium oxide in the RTGs. Each RTG is
designed to withstand re-entry, and has been tested to withstand
an explosion ten times greater than that which it would have
experienced in the Challenger cargo bay. The fuel elements are
coated with iridium to resist salt-water corrosion, and are formed
of plutonium oxide, not raw plutonium, since the oxide form is
biologically inert (though admittedly still radioactive).
There is no alternative to the use of these devices on this type of
mission since solar cells are not effective at the distances of the
outer planets, and there are no batteries with the endurance or
power density that could do the job. RTGs have been used on past
outer-planet probes with no problems.
There is a level of risk involved; but that is true of every
jumbo jet that lifts off the runway, or of thousands of other
common activities that are accepted as normal.
Christics: We say it's unsafe because plutonium is radioactive and we don't
believe NASA.
Okay, you be the judge.
* NASA, by the way, has shown remarkable public tact in handling
the Christics, carefully maintaining their rights as citizens to make
their objections known and being quick to make detailed public
responses to their allegations.
This seems the best way to handle such a situation, since "ad hominem" on
the Christics would have made NASA look bureacratic and childish -- and if
the concerns of the Christics were exaggerated, NASA should be -- and was --
able to provide persuasive answers to show the extent of their exaggeration.
--
+---------------------------------------------------------------------+
| Greg Goebel |
| Hewlett-Packard CWO / 1000 NE Circle Boulevard / Corvallis OR 97330 |
| (503) 750-3969 |
| INTERNET: gvg@hp-pcd |
| HP DESK: GREG GOEBEL / HP3900 / 20 |
+---------------------------------------------------------------------+
|
| 560.45 | Here we go! | VOSTOK::LEPAGE | Truth travels slowly | Fri Oct 13 1989 13:26 | 12 |
| Yesterday this whole court thing has become more complicated. It
seems the West German Green Party (primarily an enviromentalist party)
supports the efforts of the groups trying to stop the launch of
Galileo. They are attempting to get the World Court to stop the launch
(big deal, the US has never hesitated to ignore the World Court when it
is in their interest) and they want the Bonn government to pressure
Washington into stopping the launch (also unlikely since West Germany
is a partner in the project having supplied Galileo's retro-propulsion
module). Isn't this just getting a little out of hand?
Drew
|
| 560.46 | | VCSESU::COOK | I'm the CIA | Fri Oct 13 1989 13:33 | 10 |
|
re .45
> Isn't this getting a little out of hand?
Yes, of course. It's not unusual for people to fight technological
advances tooth and nail.
/prc
|
| 560.47 | | PAXVAX::MAIEWSKI | | Fri Oct 13 1989 16:29 | 17 |
| RE <<< Note 560.46 by VCSESU::COOK "I'm the CIA" >>>
> > Isn't this getting a little out of hand?
>
> Yes, of course. It's not unusual for people to fight technological
> advances tooth and nail.
No, not really. They are entitled to their opinion and it's up the the courts
to sort it out. I hope the launch goes ahead because I feel I understand the
risks and they are worth taking, but it's good to have the process in place
because there are plenty of other technological assults on the environment that
are not worth taking.
They are being a little unreasonable this time, but in many other cases,
the point of the environmenalist is well taken.
George
|
| 560.48 | STS-34 Update - October 13 | RENOIR::KLAES | N = R*fgfpneflfifaL | Sun Oct 15 1989 17:13 | 55 |
| Newsgroups: sci.space
Subject: NASA Headline News for 10/13/89 (Forwarded)
Date: 15 Oct 89 04:15:26 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
Friday, Oct. 13, 1989 Audio: 202/755-1788
-----------------------------------------------------------------
This is NASA Headline News for Friday, October 13:
Technicians at Kennedy Space Center have removed a suspect main
engine controller from the orbiter Atlantis and are expected to have
the replacement installed later this afternoon. Testing of the
controller will begin this evening and should be completed by noon
Saturday. Once test results are known, mission managers will meet to
set a new launch date. Launch could come as early as Tuesday.
Future technologies, ranging from new life-support systems to
nuclear surface power, have been singled out by NASA as necessary
before there can be manned missions back to the Moon and to Mars. The
projects were identified at the Internatonal Astronautical Federation
Meeting in Malaga, Spain by Doug O'Handley, of NASA's Office of
Exploration. Most will be necessary before a return to the Moon.
----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select television. All times are Eastern.
Sunday, Oct. 15.....
9:00 A.M. Launch countdown status report
Noon STS-34 crew arrival at KSC
Monday, Oct. 16.....
9:00 A.M. Launch countdown status report
1:00 P.M. Pre-launch press conference
Tuesday, Oct. 17....
7:30 A.M. Launch day coverage begins. The launch
window is open for 24-minutes beginning
at 12:57 P.M.
All events and times are subject to change without notice.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA
Headquarters, Washington, D.C.
|
| 560.49 | GALILEO Update - October 13 | RENOIR::KLAES | N = R*fgfpneflfifaL | Sun Oct 15 1989 17:16 | 71 |
| Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Galileo Update 10/13/89
Date: 13 Oct 89 22:57:18 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO DAILY REPORT
13 OCTOBER 1989
General
Spacecraft
The spacecraft still remains in its launch ready state. A "no
ops" command was sent today to reinitialize the command lost timer.
Only one additional CDU (Command Detector Unit) subcarrier lock
indication was obtained since the transmittal to the current time of
5:45 p.m.
LCET
Status remains the same; there are no problems.
STS
IUS: The IUS continues to make open circuit voltage checks on
their flight batteries. It should be noted that they have to power up
in order to perform their battery checks and in the process they check
their telemetry. No problems have been reported.
Atlantis: "A decision on an official launch date for Atlantis or
the STS-34 mission is expected on Saturday, Oct. 14." KSC Public
Affairs Office, 13 October 1989
Details
Spacecraft
The CDU (Command Detector Unit) subcarrier lock phenomenon is
being monitored and analyzed both at JPL and KSC. At KSC, RFI (radio
frequency interference) monitoring has been established for the 2115
Mhz signal emanating from a commercial carrier. Measurements have
been made at the launch pad of this signal for purposes of adjusting
the comparable measurements being made by the EMC/RFI KSC group in the
O&C Building. The hopes are that during the occurrence of CDU lock,
there would be a corresponding change in amplitude or shift in
frequency of the 2115 signal that is constantly being radiated.
However, the probability of such a corrolation is considered small.
A preliminary search of the records for CDU subcarrier lock
indications has been made for the RPM thermal conditioning test
conducted at the pad on 27 September through 1 October. There have
been no lock indications found to date. In addition, it must be
recognized that the configuration at the pad has changed between then
and now; the carry-on umbilicals have been disconnected, the payload
bay doors closed, and GSE removed. Again, it must be emphasized that
these tests are being performed for completeness and understanding and
that there has not been a violation of the launch commit criteria.
Schedule Discussion and Assessment
The current schedule is still for 17 October at 12:57 p.m. EDT.
There will be a mission status meeting on L-2 days on 15 October and
on L-1 day on 16 October when the launch date will be firmed.
Ron Baalke (818) 541-2341
Jet Propulsion Lab M/S 301-355
4800 Oak Grove Dr.
Pasadena, CA 91109
|
| 560.50 | GALILEO Update - October 16 | RENOIR::KLAES | N = R*fgfpneflfifaL | Tue Oct 17 1989 13:52 | 57 |
| Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Galileo Update
Date: 16 Oct 89 20:37:41 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO DAILY REPORT
16 OCTOBER 1989
General
NOTE: This report covers the activities of 14-16 October.
Spacecraft
The spacecraft still remains in its launch ready state. The next
spacecraft event will occur at L-20 min when a command is received
from the IUS to turn on the DMS (Data Management System) and remove
the bias from the HIC and EPD science instruments.
There has been only one additional CDU (Command Detector Unit)
subcarrier lock indications since 11:57 p.m. on 12 October. This
occurred today at 11:12 a.m. There is no JPL concern regarding these
locks; they do have a finite probability of occurring and more so in
presence of a commercial carrier near the center band of the receiver.
Spacecraft telemetry has been stable during this period without
any changes in temperatures, etc.
LCET
LCET #1 and #2 are in a ready state to support the pre launch and
post launch activities up to and including acquisition by the DSN
(Deep Space Network).
STS
A L-2 Day status meeting was held at KSC on 15 October. All
systems, including the spacecraft, gave their "go" for launch on
Tuesday, 17 October.
Today, 16 October, the L-1 Day telecon was held between all
systems and the astronauts. Again, all systems gave their "go" for
launch on tomorrow, Tuesday.
"The Galileo spacecraft is ready for launch and has had
essentially housekeeping chores during the standdown.
Launch is scheduled to occur at the opening of the launch window
or at 12:57 p.m. (EDT). The window for tomorrow closes at 1:23 p.m.
(EDT)." KSC Public Affairs Office, 16 October 1989.
Ron Baalke (818) 541-2341 ext 260
Jet Propulsion Lab M/S 301-355
4800 Oak Grove Dr.
Pasadena, CA 91109
|
| 560.51 | Launch Status update?? | LEDS::STRZEPA | | Tue Oct 17 1989 16:09 | 4 |
| Any news on the launch status for today - I've heard nothing on NPR
or the networks (at least CBS). Just wondering if Atlantis went off
yet... Thanks
|
| 560.52 | | STAR::BANKS | Zoot Mutant | Tue Oct 17 1989 16:24 | 4 |
| I just heard on the radio that the launch was delayed due to weather. Well, as
of 1:05, at least.
I was hoping someone here would have more info.
|
| 560.53 | Not today.. | WRASSE::FRIEDRICHS | Full time parent... finally! | Tue Oct 17 1989 17:12 | 6 |
| My s.o. just told me that the launch was delayed due to bad weather
at one of the abort/landing sites. She believes it was rescheduled for
tomorrow (sorry, don't know what time the window opens...)
jeff
|
| 560.54 | STS-34 Update - October 17 | CLIPR::KLAES | N = R*fgfpneflfifaL | Tue Oct 17 1989 20:23 | 29 |
| Newsgroups: sci.space
Subject: NASA Headline News for 10/17/89
Date: 17 Oct 89 20:30:40 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
Tuesday, October 17, 1989 Audio: 202/755-1788
Special P.M. Update (#2)
-----------------------------------------------------------------
This is a special 3:00 P.M. update of NASA Headline News for
Tuesday, October 17:
Rain showers in the vicinity of Kennedy Space Center this afternoon
forced postponment of the launch of the Space Shuttle ATLANTIS. Shuttle
managers late today have decided to re-schedule the launch for tomorrow
afternoon, Wednesday, October 18. The launch window will be open for a
29-minute period beginning at 12:50 P.M., Eastern time.
NASA Select television coverage of launch day activities
tomorrow, will begin at 7:30 A.M. Eastern time.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA
Headquarters, Washington, D.C.
|
| 560.55 | Additional Concern | SHAOLN::DENSMORE | But I'm feeling muuuch better now! | Wed Oct 18 1989 11:47 | 8 |
| I heard on the radio this morning that there was potential for delay in
the mission due to the earthquake in the San Francisco area yesterday.
The concern stems from the possible damage to an Air Force station in
Sunnyvale that is part of the control(?) network for the Galileo space-
craft. Has anyone heard any late breaking information?
Mike
|
| 560.56 | Slight damage, but still Mission Capable... | CTD016::J_BUTLER | Leave it better than you found it... | Wed Oct 18 1989 11:58 | 7 |
| The last I heard was that USAF engineers had inspected the site
and determined that the damage that was sustained would not
interfere with use of the Sunnyvale facilities. Sunnyvale will be
able to conduct the mission with Galileo unless aftershocks cause
more damage. (not likely)
John B.
|
| 560.57 | | CSSE::TRAPHAGAN | | Wed Oct 18 1989 12:45 | 4 |
| NPR radio confirmed .56's comment this morning. The station
sustained some damage but is operational.
JT
|
| 560.58 | It's Away! | DELNI::ROSENBERG | Every day's a new day... | Wed Oct 18 1989 15:56 | 5 |
| I just talked to my s.o. on the phone, and she says that the Shuttle
has been launched - so far, so good.
Jeff
|
| 560.59 | STS-34 On it's way! | LEDS::STRZEPA | | Wed Oct 18 1989 16:10 | 6 |
| To update: Atlantis successfully lifted off from the cape at around
12:55 PM and all appears to be fine. SRB separation went smoothly -
and the vehicle had main-engine cut-off (MECO) when the network broke
away for more San Francisco coverage.
Nice to have a little good news today. - Mike
|
| 560.60 | En-route | STEREO::FLIS | stopit!stopit!stopit!stopit! | Thu Oct 19 1989 11:24 | 5 |
| Looks like Galileo is on its way too. They reported a clean, on
time, burn after bumping out of the cargo bay and away.
jim
|
| 560.61 | Shortened mission??? | CSSE::TRAPHAGAN | | Thu Oct 19 1989 11:37 | 5 |
| This morning on the radio I heard that the 5 day mission may
be cut short due to equipment problems. Does anyone know
what this is about? THe report was the typical one-liner.
JT
|
| 560.62 | APU problem? | VMSINT::PIPER | Derrell Piper - VMS Development | Thu Oct 19 1989 12:13 | 9 |
| Two of the callouts during the assent phase mentioned something about an APU
problem:
"Atlantis, APU 1 to high-speed."
"That call, no impact."
It sounds like they're having problems with one of the APUs. That's happened a
couple of times in the past and each time they shortened the mission by a day or
so.
|
| 560.63 | GALILEO Update - October 18 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Oct 19 1989 12:41 | 48 |
| Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Galileo Update
Date: 19 Oct 89 03:13:27 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO DAILY REPORT
18 OCTOBER 1989
General
STS 34, with Galileo aboard, was launched from KSC at 12:53 p.m.
EDT on 18 October 1989. Once in orbit the IUS went through a
predeployment checkout. A "Mission Phase 6" error did occur when
attempting to lock in the RF link to Sunnyvale through the PI (Payload
Integrator), but this was determined to be static on the RF link. The
tilt table was then raised up to a 58 degree angle, and Galileo was
deployed at a time of 6 hours 21 minutes 23.397 seconds after launch,
on the 6th orbit around Earth.
The tilt table was then lowered back down to its initial -6
degrees. At about 15 minutes after deployment Atlantis executed a
separation burn. Live pictures were then transmitted to Houston
control showing the payload bay area and the inside of the shuttle. At
7 hours 21 minutes after launch the 1st stage IUS burn was executed
and verified by Sunnyvale. The 2nd stage UIS burn occurred 5 minutes
later to place Galileo on an Earth escape velocity of 7.1 miles/sec.
The VTR playback of the Galileo deployment was then transmitted to
Houston.
Debris looking like ice particles was seen to be floating around
the Shuttle. Houston control questioned the crew about what the debris
could be.
At 7 hours 46 minutes after launch, the IUS went into a 1st stage
spinoff to deploy the RTG and science booms. The 2nd stage IUS spinoff
at a rate of 2.9 revolutions/second for the separation of the IUS from
Galilio sooned followed. At this point telemetry data were transmitted
and recieved by DSN (Deep Space Network).
Galileo is expected to arrive at Venus in February 1990 on its
first leg of its journey to Jupiter.
Ron Baalke (818) 541-2341 ext 260
Jet Propulsion Lab M/S 301-355
4800 Oak Grove Dr.
Pasadena, CA 91109
|
| 560.64 | STS-34/GALILEO Update - October 18 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Oct 19 1989 12:47 | 74 |
| From: tkelso@blackbird.afit.af.mil (TS Kelso)
Newsgroups: sci.space,sci.space.shuttle
Subject: NASA Prediction Bulletins: Space Shuttle
Date: 18 Oct 89 23:38:58 GMT
Organization: Air Force Institute of Technology; WPAFB, OH
The most current orbital elements from the NASA Prediction
Bulletins are carried on the Celestial RCP/M, (513) 427-0674, and are
updated several times weekly. Documentation and tracking software are
also available on this system. As a service to the satellite user
community, the most current elements for the current shuttle mission
are provided below. The Celestial RCP/M may be accessed 24 hours/day
at 300, 1200, or 2400 baud using 8 data bits, 1 stop bit, no parity.
STS-34
1 20297U 89 84 A 89291.73333059 .00085300 00000-0 25599-3 0 14
2 20297 34.3150 148.5416 0006349 265.2700 302.1406 15.90963529 06
Dr TS Kelso Asst Professor of Space Operations
tkelso@blackbird.afit.af.mil Air Force Institute of Technology
Newsgroups: sci.space
Subject: Galileo Status for 10/18/89 (Forwarded)
Date: 19 Oct 89 03:36:55 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
The Jupiter-bound NASA Galileo spacecraft was successfully
injected on a Venus transfer orbit at 8:20 P.M. EDT October 18, 1989,
seven hours and 27 minutes after liftoff of space shuttle Atlantis
from the Kennedy Space Center.
All early indications are that the spacecraft systems are
operating normally, according to Galileo Project Manager Richard J.
Spehalski of the Jet Propulsion Laboratory.
"The shuttle and Inertial Upper Stage flights were near-perfect.
The Galileo Project is delighted to be on our way to Jupiter via
flybys of Venus and Earth. Our heartiest thanks go out to the many
people who were part of getting this mission successfully started,"
Spehalski said.
Galileo and the Inertial Upper Stage (IUS) were deployed from
Atlantis's payload bay by the STS-34 crew while the shuttle orbiter
was overflying the Gulf of Mexico near Brownsville, Texas, on its
sixth revolution of Earth. At injection -- burnout of the second
stage of the IUS -- the spacecraft ground track was crossing the
Philippine Sea. Galileo separated from the IUS at 9:07 P.M. EDT.
Shortly before separation, Galileo deployed its RTG booms and
extended the magnetometer boom. It was expected to establish its fix
on the Sun at 9:56 P.M. EDT. The spacecraft radio signal will be
acquired by the Deep Space Network station near Canberra, Australia,
at 12:01 A.M. EDT October 19.
Galileo will fly near Venus in February 1990 and swing twice past
the Earth for gravity assists before going on to a December 1995
arrival at Jupiter. Asteroid observations along the way may be planned.
Newsgroups: sci.space
Subject: Galileo Status for 10/18/89 [Corrected] (Forwarded)
Date: 19 Oct 89 04:04:48 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
In the Galileo status report just filed, there is reference to
Atlantis being over Brownsville Texas on Rev 6 when Galileo was
deployed. It was actually Rev 5 and the geographic range varies in
description from Sonora, Mexico, through Chihuahua, Mexico to
Brownsville, Texas (a matter of preference, actually) but the orbit is
Rev 5, and NOT 6.
Charles Redmond, NASA Headquarters Newsroom
|
| 560.65 | Ice crystals around Atlantis | VIRRUS::DIEWALD | Inspector Gregson, Scotland Yard, at your service... | Thu Oct 19 1989 14:14 | 12 |
| To my utter delight, my cable company carries NASA Select. I was watching
it when they lit the Galileo IUS. While the burn was in progress, the
astronauts were dumping the videotape of the Galileo deployment, they were
discussing a problem with the ground. From what we could make out, they were
carrying too much water.
The ice crystals formed shortly after they began dumping some of the excess
water.
I still don't understand why they had too much water, though.
Jeff
|
| 560.66 | STS-34 Update - October 19 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Oct 19 1989 18:40 | 57 |
| Newsgroups: sci.space
Subject: NASA Headline News for 10/19/89 (Forwarded)
Date: 19 Oct 89 18:10:19 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
Thursday, Oct. 19, 1989 Audio: 202/755-1788
-----------------------------------------------------------------
This is NASA Headline News for Thursday, October 19:
"Galileo is on its way to another world," radioed Atlantis
Commander Don Williams to Mission Control. At 7:15 last night,
about 6.5 hours after liftoff, the crew of the space shuttle
Atlantis successfully sent the spacecraft Galileo on its 6-year
journey to Jupiter.
About an hour later, Galileo's Inertial Upper Stage booster fired
twice...slowing the spacecraft's motion so that it would fall toward
the inner solar system and the first destination...Venus, on its path
to Jupiter.
Galileo will fly near Venus in February 1990 and swing twice past
Earth for gravity assists before going on to a December 1995 arrival
at Jupiter.
Atlantis...after a flawless liftoff, has developed a problem with
a cooling system. Mission Control said shortly after achieving orbit,
the flash evaporator system automatically switched from its normal low
cooling mode using the topper subsystem to the high load subsystem.
The flash evaporator system switched over normally to the payload bay
radiators when the payload bay doors were opened, in preparation for
deployment of Galileo. Mission controllers and the crew will continue
to monitor the system.
Meanwhile, during the remaining portion of the flight, the crew
plans to conduct a variety of scientific experiments...and also use a
high-quality Imax movie camera for a documentary for the National Air
and Space Museum.
Landing is currently scheduled for Monday at Edwards Air Force
Base, California.
-----------------------------------------------------------------
STS-34 television coverage
NASA Select television will provide near continuous coverage of
the entire STS-34 mission, including in flight crew activities
and change of shift status briefings from Mission Control in
Houston. Landing is scheduled for Monday afternoon.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC) NASA
Headquarters, Washington, D.C.
|
| 560.67 | Solar flares/magnetic storms | TUNER::FLIS | stopit!stopit!stopit!stopit! | Fri Oct 20 1989 11:50 | 9 |
| Could the recently reported 'large' solar flare impact this mission
at all? As I understand it the radiation levels durring a solar
flare can be of concern as well as physical impairment of the orbit
(both that of the shuttle and Galileo).
From what I understand, the wave front should hit us sometime today.
jim
|
| 560.68 | Atlantis TV Report: CNN Sunday morning | LANDO::STONE | | Fri Oct 20 1989 20:36 | 6 |
| 560.70 | STS-34 mission end details; info on next two flights | RENOIR::KLAES | N = R*fgfpneflfifaL | Tue Oct 24 1989 19:55 | 62 |
| Newsgroups: sci.space
Subject: NASA Headline News for 10/24/89 (Forwarded)
Date: 24 Oct 89 18:24:42 GMT
Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
-----------------------------------------------------------------
Tuesday, Oct. 24, 1989 Audio: 202/755-1788
-----------------------------------------------------------------
This is NASA Headline News for Tuesday, October 24:
The Space Shuttle Atlantis and its crew...Commander Donald
Williams, Co-pilot Michael McCulley and Franklin Chang-diaz, Shannon
Lucid and Ellen Baker...landed safely yesterday morning at Edwards Air
Force Base. The landing occurred two orbits earlier than originally
planned because of predicted high winds on the desert lake bed later
in the afternoon.
William Lenoir, Acting Associate Administrator for Space Flight,
said "the vehicle looks amazingly clean. We did not see, with a quick
inspection, any significant tile damage--a little nick here and a nick
there."
The schedule calls for Atlantis to ride back to Kennedy Space
Center aboard the 747-carrier transport jet over the weekend.
Meanwhile, technicians at KSC plan to roll out the Space Shuttle
Discovery to launch pad 39-B, beginning at 12:01 A.M. Wednesday. Its
crew...Commander Frederick Gregory, Co-pilot John Blaha and Manley
Carter, Story Musgrave and Kathryn Thornton...plan to fly to KSC this
weekend, and board the orbiter on Monday for a dress-rehearsal
countdown at the launch pad. Discovery is scheduled to fly a
classified DoD mission later in November.
The schedule currently calls for the orbiter Columbia to be moved
to launch pad 39-A on November 22, for a planned night time launch
around December 18. Its crew...Commander Daniel Brandenstein,
Co-pilot James Weatherbee and Bonnie Dunbar, David Low and Marsha
Ivins plan to spend 10 days in orbit to deploy a military communications
satellite and retrieve the Long Duration Exposure Facility (LDEF).
"The next two launches look like they're pretty much on schedule,"
Lenoir said. "There's a very good likelihood that the next two
missions will be in the air over the two upcoming holidays,
Thanksgiving and Christmas."
-----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select television. All times are Eastern.
Thursday, Oct. 26:
11:30 A.M. NASA Update will be transmitted.
All events and times are subject to change without notice.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA
Headquarters, Washington, D.C.
|
| 560.71 | GALILEO Update - October 30 | RENOIR::KLAES | N = R*fgfpneflfifaL | Tue Oct 31 1989 12:37 | 29 |
| Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Galileo Update
Date: 30 Oct 89 22:39:28 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS UPDATE
30 OCTOBER 1989
Galileo is now 2.5 million miles from Earth traveling at 59,845
mph as it slowly drops in towards the orbit of Venus. Its radio
transmitter is now operating at 30 watts and its propulsion system has
been operated twice in tests and for maintainence purposes. Galileo's
atmospheric probe has been checked out last week and its condition is
fine. The spacecraft's ion detector was turned on during the latter
part of the solar flare and has measured heavy ions in the range of
130 million volts, none of which affected Galileo's electronics. On
Wednesday, the spinning of the lower part of the spacecraft where the
optical sensors are mounted will be stopped. At present the whole
spacecraft is spinning at 2.9 revolutions per minute. The top part of
Galileo where controller electronics, power, propulsion, radiation and
magnetic field sensors, and radio attennas are located will continue
spinning for the duration of the mission.
Ron Baalke | (818) 541-2341 x260
Jet Propulsion Lab M/S 301-355 | baalke@mars.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.72 | GALILEO Update - November 7 | RENOIR::KLAES | N = R*fgfpneflfifaL | Wed Nov 08 1989 11:46 | 61 |
| Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Galileo Update
Date: 7 Nov 89 20:17:12 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO WEEKLY STATUS
November 7, 1989
As of 8 a.m. (PST) Tuesday, November 7, 1989, the Galileo
spacecraft is 4.16 million miles from Earth, 28.2 million miles along
its path to its first gravity assist at Venus. Round-trip light time
is almost 45 seconds. Galileo still has 157 million miles to go just
to reach Venus; it is reducing that distance at a rate of just over
60,000 mph, increasing slowly as it comes closer to the Sun. Jupiter
lies about 2.4 billion miles ahead along the VEEGA trajectory.
The spacecraft is spinning at about 3 rpm around an axis pointed
a few degrees from the Sun. It is transmitting telemetry at 7.68
kilobits per second; the RTGs are providing about 570 watts of power,
60 watts more than needed at present. The heavy ion counter, an
engineering instrument which detects charged particles from the atomic
weight of carbon through that of iron, has been seeing at least one
every 2/3 second, mostly oxygen. It detected and characterized the
recent major solar flare.
Last week Galileo's flight team continued checkout, maintenance,
and characterization of various elements of the spacecraft. Notable
among these was the dual-spin mode, in which a major part of the
spacecraft, carrying the scan platform with 4 instruments, the probe
and probe relay system and associated electronics, was spun in reverse
while the rest of the machine was still spinning at about 3 rpm. This
mode, which allows the camera and other remote-sensing instruments to
be aimed at planetary targets, was satisfactorily maintained during
the 70-minute checkout.
The spacecraft was then put back in the all-spin mode for other
planned cruise operations. These included sun pointing (moving the
spin axis from about 10 down to 1.25 degrees from the Sun line).
Before and after this maneuver, the star sensor was given a star map
and turned on to determine attitude and spin rate, which it did as
planned. An additional propulsion system maintenance sequence was
done early Monday.
The first trajectory correction maneuver is planned for November
9, 10, and 11; it will change the spacecraft velocity by less than 17
meters per second (about 38 mph). Small axial and lateral thrusters
will fire in pulses of about 1-sec duration.
Nothing in the mission so far has ruled out the possibility of an
asteroid encounter (Gaspra, between the first and second Earth
flybys). However, no final decision on asteroid encounters will occur
until after the Venus flyby in February, when Galileo's flight team
and other project personnel evaluate the post-Venus flight path and
the propellant margins at that time.
Ron Baalke | (818) 541-2341 x260
Jet Propulsion Lab M/S 301-355 | baalke@mars.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.73 | adjust our clocks :-) | SUBSYS::DOUCETTE | Jim Doucette | Thu Nov 09 1989 11:01 | 15 |
| <><><><><><><><> T h e V O G O N N e w s S e r v i c e <><><><><><><><>
Edition : 1938 Thursday 9-Nov-1989 Circulation : 7647
VNS TECHNOLOGY WATCH: [Mike Taylor, VNS Correspondent]
===================== [Nashua, NH, USA ]
Galileo Flyby Slows Earth Orbit
The space agency NASA calculated that Galileo's two flybys if Earth
will slow the Earth's orbital velocity by 9.6 billionth-billionth of
a mile per hour. That would alter the Earth's position by 5.3 inch
per billion years. NASA did not estimate how much sooner the entire
human race will perish when the Earth falls into the Sun.
{AW&ST October 1989}
|
| 560.74 | | CTD024::TAVARES | John -- Stay low, keep moving | Thu Nov 09 1989 13:32 | 7 |
| You know, I read that and I thought, if something as small as
Galileo could distrub the Earth, what about the cumulative effect
of all the space flights and junk we have up there?
Its cute to talk of 5 inches in a billion years, but I'm sobered
by the thought that this is just a teeny part of what's going
on. I shall never sleep again for the rest of my life.
|
| 560.75 | The sky is falling! The sky is falling! | REPAIR::RICKETTS | Have you tried kicking it? | Thu Nov 09 1989 13:38 | 2 |
| Just waiting for the Christic Institute and the Florida Coalition
for Peace and Justice (see 560.4) to get hold of THAT one! 8*)
|
| 560.76 | It really isn't that bad | VOSTOK::LEPAGE | Truth travels slowly | Thu Nov 09 1989 15:27 | 22 |
| Re: .74
Actually, the space junk in orbit around the Earth in the long run
(i.e. over billions of years) will have little if any net effect since
it is in orbit around the Earth (and on average the net effect on the
speed of the Earth is zero) and eventually nearly all of it falls back
to Earth anyway (the net effect being once again zero).
What makes Galileo so special is that it will flyby the Earth twice
and gain energy to go to Jupiter (and of course the Earth loses the
same amount of energy). Even then in the long run that's really
nothing. For over 4 billion years (and for 5+ billion years to come)
asteroids have been passing the Earth and either gaining energy from or
losing energy to the Earth. Since these asteroids weigh millions and
even billions of times more than Galileo, Galileo's small effect on
Earth's speed would be insignificant compared to what the asteroids
have done. In fact, right now for all we know an asteroid (or maybe
more precisely a meteoroid) a fraction of a meter in diameter is
passing the Earth in just the right way to transfer to the Earth the
energy Galileo will need. And as a result, the Earth will be saved from
its 5 inches per billion year speed deficit and the Christic Institute.
Drew
|
| 560.77 | | PAXVAX::MAIEWSKI | | Thu Nov 09 1989 20:55 | 7 |
| I'll bet that back in the '50s when they were doing atmospheric testing of
H-bombs that they induced larger changes in the earth's orbit. Anyone have any
idea how much the earth's orbit would change from a 10 megaton blast? Of course
that's the equivilent of 10 megatons of TNT, not 10 megatons of energy, so I
guess you'd have to know how much force there was in a ton of TNT.
George
|
| 560.78 | Probably not at all... | REPAIR::RICKETTS | Have you tried kicking it? | Fri Nov 10 1989 06:14 | 14 |
| ...unless the blasts actually threw material out of the atmosphere
at greater than escape velocity. This would produce an action=reaction
that could push the earth around.
In fact, of course, more or less all the material going up in
the blast comes back down again; this is what fallout is. If the
explosion took place fairly high in the atmosphere, or was VERY
big, (I suspect we are talking '000s rather than '0s of megatons
here-anyone care to put a figure on it?) some might escape,
but the mass involved would probably be small. Remember that
the atmosphere is essentially part of the earth. An atmospheric
explosion is no more going to change the motion of the earth than
a subterranean one, UNLESS material is ejected from the planet,
thereby changing its momentum.
|
| 560.79 | Save your momentum for valuable cash prizes | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Fri Nov 10 1989 14:10 | 11 |
| From memory, the Starfish and Argus blasts were not very powerful. Both
were above the lower atmosphere. Since Starfish (I think) lead to a
temporary radiation belt, I'd suspect that very little matter escaped.
I could dig out the info if anyone is that interested.
I've been waiting to see if any of the neo-luddites would pick up on
the idea of momentum stealing (gravity assist if you prefer). I wonder
if we'll see pressure for Congress to pass a law about the Conservation
of Momentum? :-))
gary
|
| 560.80 | | PAXVAX::MAIEWSKI | | Fri Nov 10 1989 14:30 | 5 |
| Of course, if the earth slows down, it will be warmer in it's lower orbit.
Seems I saw this on the twlight zone once. The skiers won't like it but the
beach crowd will be happy.
George
|
| 560.81 | greenhouse | BEATLE::STRANGE | Keep on rockin' in the free world | Fri Nov 10 1989 15:49 | 8 |
| re:.80
We're probably already doing a good job of warming ourselves up using
different methods, like the one Venus uses, and we don't even have to
launch anything to do that! :-)
Steve
|
| 560.82 | GALILEO Update - November 14 | RENOIR::KLAES | N = R*fgfpneflfifaL | Wed Nov 15 1989 14:44 | 37 |
| Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Galileo Update
Date: 14 Nov 89 22:14:38 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Status Report
14 November 1989
The first course change maneuver for Galileo was successfully
completed last Saturday. The two day maneuver began last Thursday
morning at a distance of 28,200,000 miles from Earth, and consisted of
a long series of time pulses of Galileo's 2.2 pound thrusters. A
shorter continuous period of firing would have overheated the thrusters.
The total speed change was 38 mph which will move Galileo closer
to its target point near Venus, but changes the arrival time to Venus
on February 9th by only a few minutes.
During the maneuver, a temperature sensor on one of the thrusters
failed. However, in the future the temperature of that thruster can be
deduced from nearby thruster readings.
Galileo is now 55,162,000 miles from Earth and traveling at
60,807 mph. After gaining momentum from Venus's gravity, Galileo will
return to Earth in December next year, use Earth's gravity to loop out
to the asteroid belt, and return back to Earth again two years later
for a final gravity push to reach Jupiter in December 1995.
Several more days of tracking are needed to determine the
accuracy of last week's course change.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.83 | GALILEO Update - November 22 | RENOIR::KLAES | N = R*fgfpneflfifaL | Mon Nov 27 1989 16:25 | 51 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update (Forwarded)
Date: 22 Nov 89 22:46:21 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO WEEKLY STATUS
November 22, 1989
As of Wednesday, November 22, the Galileo spacecraft is 6.97
million miles from Earth (round-trip light time 75 seconds or 1 1/4
minutes); it has travelled 50 million of the 185 million miles around
the Sun to its Venus gravity-assist rendezvous in February 1990. The
first trajectory correction maneuver (carried out November 9-11) was
very successful; trajectory analysis indicates a slight over-performance.
TCM-2 (planned for December 22) is expected to be less than 1 meter per
second; TCM-1 was almost 16 m/sec, mostly toward the Sun and mostly to
remove an intentional bias rather than launch errors.
The maneuver was conducted in the dual-spin mode, with the 4100-lb
main section of the spacecraft rotating at about 3 rpm while the
700-pound lower section and the 750-pound atmospheric probe are
counter-rotated to stay sta-tionary. In this mode, Galileo's camera
and other remote sensors can be precisely aimed during a planetary
flyby. The spacecraft remained in this mode, so that turns to keep it
Sun-pointed can be done automatically.
Spacecraft communication equipment was switched on November 15
from Low Gain Antenna 1 (looking toward the Sun) to LGA 2 (looking the
opposite way) to keep up with the changing Sun-spacecraft-Earth
geometry. On the 19th, the data rate was reduced from 1200 to 40 bits
per second to free the DSN 70-meter antenna briefly for other
projects. The rate goes back up today.
The spin rate is currently just over 3 rpm, and the spin axis is
being moved nearly every day to keep the spacecraft Sun-pointed within
a degree. The RTGs continue to deliver about 570 watts of electric
power. All temperatures and propulsion system pressures are within
acceptable ranges, although the dust detector instrument is
significantly cooler than expected.
The magnetometer and heavy ion counter are the only instruments
powered at present. A four-day science checkout is scheduled for
December 27-30 in preparation for the Venus science encounter in
February.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.84 | GALILEO's mission to Earth | RENOIR::KLAES | N = R*fgfpneflfifaL | Mon Nov 27 1989 16:26 | 51 |
| From: henry@utzoo.uucp (Henry Spencer)
Newsgroups: sci.space,sci.space.shuttle
Subject: Space news from October 9 AW&ST, part 1
Date: 27 Nov 89 07:03:27 GMT
Organization: U of Toronto Zoology
Galileo will attempt various experiments during its Earth encounters.
Plans are not yet fixed, but among the ideas are:
- A high-speed movie of the Earth approach, starting from 20Mmi
with Earth as a small crescent and moving in to encounter (with
a resolution of 50ft or so). The two encounters will pass over
Egypt and South Africa respectively.
- Detailed examination of the Moon with modern instruments.
About 2/3 of the Moon has not been seen well for two decades.
Galileo will get good views of areas that have never been
mapped at high resolution.
- Examine lunar polar craters for evidence of frozen volatiles.
Galileo's instruments are not ideal for this but could give
some information.
- Look for evidence of the swarms of mini-comets that some think
contribute a significant amount of water to Earth. Lunar impacts
should result in a considerable cloud of hydrogen around the
Earth-Moon system, which could be detectable from deep space.
- Use Galileo's dust detector to look for a "dust belt" in the
vicinity of Earth's orbit; one theory holds that dust falling
inward towards the Sun from the asteroid belt could be delayed
near Earth, forming a thin belt.
Galileo's second asteroid encounter is probably off the agenda
unless cruise fuel consumption is significantly lower than predicted.
Even the first encounter will be endangered if consumption is worse
than expected. Nothing will be decided until after Venus encounter in
February.
JPL will start CRAF/Cassini construction work in 1991, the first
major spacecraft start at JPL since Galileo over a decade ago. There
is some concern about the loss of crucial skills in the hiatus.
A graph of US scientific launch activity in the last 30 years is
somewhat striking. From 1958 to 1978, the longest gap between major
exploration missions was one year. Between Pioneer Venus in 1978 and
Magellan this May... nothing.
Henry Spencer at U of Toronto Zoology
uunet!attcan!utzoo!henry henry@zoo.toronto.edu
|
| 560.85 | STS-34 astronauts honored at JPL | RENOIR::KLAES | N = R*fgfpneflfifaL | Wed Nov 29 1989 20:45 | 22 |
| Newsgroups: sci.astro
Subject: Galileo Astronauts Honored at JPL
Date: 29 Nov 89 21:05:21 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
The crew of the STS-34 Space Shuttle Mission was honored today at
the Jet Propulsion Laboratory. The major objective of the STS-34
flight was the deployment of the spacecraft Galileo which was
accomplished last October 18. The ceremony occurred at noon in the
JPL mall area. Dr. Lew Allen, the director of JPL, presented each of
the astronauts with a personalized plaque commemorating the Galileo
deployment. Don Williams, the commander of STS-34 and mission
specialists Ellen Baker were then introduced and each gave a speech in
front of the JPL personel. Time was then set aside for the JPL
employees to chat with the astronauts and to get their autographs.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.86 | Whoopie | EPIK::BUEHLER | We didn't start the fire. But we're trying to fight it. | Thu Nov 30 1989 14:09 | 7 |
| > The crew of the STS-34 Space Shuttle Mission was honored today at
>the Jet Propulsion Laboratory.
That's fine. Now what about the people who designed, built, maintained
and launched that flight?
John
|
| 560.87 | GALILEO Update - November 29 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Nov 30 1989 15:15 | 39 |
| Newsgroups: sci.space
Subject: Galileo Update 11/29/89 (Forwarded)
Date: 30 Nov 89 16:01:20 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO WEEKLY STATUS
November 29, 1989
As of Wednesday, November 29, the Galileo spacecraft is 8.15
million miles from Earth (round-trip light time 88 seconds, almost 1.5
minutes); it is now more than 50 million miles along its 185-million-mile
path to Venus.
The last week was a relatively uneventful period for Galileo's
flight team; owing to the holiday only a few activities were scheduled,
including Sun-pointing Saturday, yesterday, and today, and an RPM
maintenance (flushing the propulsion system plumbing) on Monday.
The spacecraft is still in the dual-spin mode, with the spun
section rotating at approximately 3 rpm. It is transmitting telemetry
at 1200 bits per second via LGA-2, the low-gain antenna attached to a
boom pointing down (away from the Sun) from one of the RTG booms. The
DSN tracking data are clear enough to show the back-and-forth motion
of this antenna as the spacecraft rotates.
The third operational sequence (of six covering the period from
launch through Venus encounter) will be sent to Galileo Friday and
take effect Saturday, December 2. It consists of continued cruise
operations including further spacecraft characterization. The second
trajectory change maneuver (removing the rest of the original bias)
and the four-day science checkout, scheduled for late December, will
be part of EV-4, the next sequence.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.88 | GALILEO Update - December 6 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Dec 07 1989 14:37 | 38 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update 12/6/89 (Forwarded)
Date: 6 Dec 89 23:17:45 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
December 6, 1989
The Galileo spacecraft is 9.25 million miles (50 light-seconds)
from Earth today. It has gone 71 million miles along its curving road
to Venus in the 49 days since launch, and has 114 million miles and 65
days to go until Venus encounter and almost 2-1/2 billion miles, 6
years and 2 days to Jupiter. Things are going well.
Since last Saturday, the third Earth-Venus cruise sequence of
commands has been in effect. The principal activities at this time
involve characterizing (exercising, checking out and understanding)
spacecraft functions and equipment to be used in Venus scientific
observations in February 1990. Last month's characterization focused
on elements used in the November 9-11 trajectory change maneuver --
propulsion, attitude control, communications. This month's adds such
things as articulation control, particularly the scan actuators.
Galileo's scientific instruments will be checked out separately
December 27-30.
The spacecraft is still in what is termed dual-spin mode, with the
main part of the orbiter rotating at about 3 rpm and the lower portion
of the craft fixed in relation to space. Temperatures are within
acceptable limits, though several are still cooler than predicted.
Automatic maneuvers are performed as needed every day or so to keep
the spacecraft oriented in relation to the Sun.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.89 | GALILEO Update - December 13 | RENOIR::KLAES | N = R*fgfpneflfifaL | Wed Dec 13 1989 20:46 | 30 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update 12/13/89
Date: 13 Dec 89 20:28:56 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Status Report
December 13, 1989
Galileo is now 10.33 million miles from Earth and a little
under 31 million miles from Venus which it will pass on February 9.
Thorough checkouts of Galileo's engineering systems continue as
scientific instruments aboard the spacecraft are turned on and will
continue through the end of the month.
Because of the Sun's heat near Venus, Galileo's large radio
antenna will be kept unfurled and shaded until just before it returns
to Earth in December next year. It will then be able to radio its
Venus science data stored in its tape recorder.
After a long loop out to the asteroid belt, Galileo will return
to Earth again in December, 1992, and begin its final leg to Jupiter
which it will then orbit and begin a 20-month study of the planet and
its moons.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.90 | GALILEO Update - December 13 | RENOIR::KLAES | N = R*fgfpneflfifaL | Fri Dec 15 1989 13:04 | 41 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update 12/13/89 (Forwarded)
Date: 13 Dec 89 22:25:21 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
December 13, 1989
The Galileo spacecraft is 10.3 million miles or 55 light- seconds
from Earth today. It has travelled a total of 82 million miles since
launch, with 102 million ahead in the trajectory to Venus. Closest
approach to that planet will be at about 10 p.m. PST February 9, 1990,
at about 10,000 miles from the center of Venus (6,200 miles above the
cloudtops).
Things are generally going well. The power margin, temperatures,
propellant-tank pressures, spin rate and orientation parameters are
nominal or within acceptable ranges.
During the pre-Venus characterization exercises begun last week,
the scan platform, which carries the camera and other remote-sensing
instruments was moved about both axes for the first time. The
platform was elevated about 160 degrees from the zero (antisolar)
position and rotated 180 degrees around its axis (parallel to the spin
axis); after other movements, it was returned to the zero position.
The ultrastable oscillator, to be used in radioscience experiments,
was also operated for the first time, and a series of tests was
performed to characterize the telecommunication system hardware.
Galileo's mission team has completed the EV-4 (Earth-Venus #4)
sequence, the operational program defining spacecraft events from
December 18 through the first week of January. This sequence includes
the second trajectory correction maneuver, set for December 22, and
the 4-day science checkout, December 27-30.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.91 | Stay Close To Your Desks And Never Go To Sea... | CTD024::TAVARES | Nuke Christmas Music! | Fri Dec 15 1989 19:15 | 6 |
| Just a nit from an old sailor...the statement in .89 that the
antenna will be kept "unfurled and shaded" should read "furled
and shaded". A furled sail is wrapped up, an "unfurled" sail
(I've never heard the term used this way) is set.
signed -- Chicken Of The Sea
|
| 560.92 | GALILEO Update - December 20 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Dec 21 1989 21:11 | 55 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update 12/20/89
Date: 21 Dec 89 17:21:43 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
December 20, 1989
The Galileo spacecraft is 11.3 million miles or just over 1
light-minute from Earth today. It is just over halfway (or about 93
million miles) along its path to Venus encounter, and is going 67,104
mph in its orbit. The spin configuration is in cruise mode, with the
upper part of the spacecraft spinning at 3.15 rpm around the axis
pointed within a couple of degrees of the Sun, and the lower part
despun, fixed in orientation.
The EV-4 (Earth-Venus #4) sequence is currently in effect,
defining spacecraft operating states and functions. The celestial
reference loss and science alarm monitors are disabled as planned. The
telemetry rate is 1200 bits per second, and telemetry indicates that
all temperatures and pressures are at acceptable levels. The
spacecraft's attitude Sun point angle is currently at 1.87 degrees,
plus or minus 0.3 degrees.
The spacecraft DC voltage imbalance measurement, which indicates
the potential difference between the power busbars and the spacecraft
chassis, has been fluctuating. The DC bus voltage imbalance has been
slowly increasing and has reach nearly 17.3 volts. This does not
reflect a fluctuation in spacecraft electrical power, which continues
to show the normal margin. Nor does it pose any hazard to the
spacecraft, which was designed to function at any level of imbalance
up to short-to-chassis; Voyager 1 has been operating acceptably since
early 1988 in this condition.
On Friday the Galileo spacecraft will perform its second
trajectory change, moving the Venus closest approach point to the
desired 10,000 miles from planet center (about 6,200 miles above the
cloud tops). Closest approach will occur about 10 p.m. PDT February
9. At injection, the aim point was biased out to several hundred
miles from Venus. This maneuver, will thrust mostly at right angles to
the sun line, with a magnitude of about 3/4 of 1 meter per second
(about 1/20 the first maneuver). It will be done in four segments or
pulse chains, taking about 2-1/4 hours in all.
All of the orbiter science instruments are off except for the
magnetometer and HIC. Next week all the orbiter science instruments
will be checked out in a four-day programmed sequence, preparing for
Venus encounter.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.93 | GALILEO Update - January 3 | RENOIR::KLAES | N = R*fgfpneflfifaL | Fri Jan 05 1990 12:45 | 41 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update 01/03/90
Date: 4 Jan 90 17:30:52 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
January 3, 1990
Today the Galileo spacecraft is 13.6 million miles from Earth.
Round-trip light time is almost 2+ minutes. It has travelled 116.4
million of the 185 million miles in its path to Venus encounter, now
about 5 weeks away. Heliocentric velocity has risen to 71,020 mph.
The spacecraft's spin rate is 3.14 rpm as estimated by the star
scanner, and the attitude sun point angle is at 0.5 degrees.
Last week's four-day science checkout was generally successful.
All orbiter instruments were exercised and tested; the magnetometer,
the heavy ion counter, the dust detector, and the UV spectrometer are
still powered. On December 22, Galileo conducted a successful second
trajectory correction maneuver, as programmed and monitored by the
flight team.
At present the mission is proceeding as planned with the
spacecraft in normal dual-spin cruise mode. All temperatures and
pressures are within acceptable limits, and the downlink telemetry
rate is 1200 bits per second.
DC and AC voltage imbalance measurements continue to fluctuate.
All other power related measurements are stable and are as expected.
On January 8, the operational sequence EV-4 (fourth sequence in
Earth-Venus cruise) concludes, and EV-5 begins. EV-6 will contain the
Venus flyby operations.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.94 | GALILEO Update - January 9 | RENOIR::KLAES | N = R*fgfpneflfifaL | Tue Jan 09 1990 17:32 | 97 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/09/90
Date: 9 Jan 90 18:11:43 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Mission Status
January 9, 1990
Galileo is now 14,308,100 miles from Earth, 14,731,150 miles
from Venus and is travelling at a Heliocentric velocity of 71,6390
miles per hour. Round trip light time is 2 minute, 32 seconds. The
spacecraft's spin rate is 3.15 rpm and the attitude sun point angle
is 2.05 degrees.
Four SITURNS to the Sun were successfully performed without
incident on December 26, 29 and January 2 and 5.
A command was sent on December 22 to turn off the EPD detector
bias voltage. This action was taken to preclude damage or degradation
to the sensitive detectors/electronics as a result of the AC bus
voltage imbalance condition. An indefinite removal of bias voltage
will not cause damage/degradation to the detectors, however, a voltage
bias-on condition is preferred.
The science checkout portion of the EV-4 sequence was
successfully performed from December 27 through December 30. Prior to
the instrument checkout activities, science covers were
released/deployed for the DDS, EUV, UVS, and the PPR. All spacecraft
pyro event indications associated with cover actuators were as planned
and without incident. It is pointed out that the PLS and EPD covers
were deployed/opened several weeks earlier; the SSI cover, which is
transparent, is not planned for release until after Earth 2 flyby.
Subsequent to the cover events, a fairly extensive science instrument
checkout was performed. In general, the scientists were pleased with
the nature and the extent of the checkout activities and the operation
of the instruments. Detailed data analysis is in process.
The NIMS optics and radiator covers were released on January 3 as
planned. Prior to cover deployment, the scan platform was moved from
the 153 degree cone position to the 30 degree cone position and the
spacecraft was transitioned from dual-spin to all-spin to ensure no
possibility of cover deployment contact with any part of the
spacecraft. Shortly after cover deployment, the scan platform was
repositioned to 153 degree cone location. Spacecraft pyro event
indications were as expected with no anomalies observed. Subsequent to
the pyro events, NIMS temperatures began dropping thus providing some
additional evidence of cover deployment. However, the rate of
temperature decrease was substantially slower than expected. Concern
was raised that possibly the radiator cover did not fully deploy and
may be "hung-up" and subsequently come free and perhaps hit some part
of the spacecraft.
An intensive analysis performed by the flight team and design
personnel concluded that it is extremely unlikely that the NIMS cover
if not deployed could hit the spacecraft or damage would occur if it
did. The flight team is now investigating possible actions to confirm
cover deploy and if not deployed alternate actions to assure full
deployment. Navigation data is also being analyzed to help determine
the state of NIMS cover deployment.
Continued with telecommunication subsystem tests performed on
January 4; all tests were completed without incident.
A Delayed Action Command (DAC) was sent on January 4 to close the
PPR cover prior to the scheduled sun acquisition on January 5. The
PPR cover was left open as a result of the thruster fire all clear
alert code associated with an earlier performed HGA correction. The
cover close command was needed to protect the PPR from possible
thruster plume contamination associated with the sun acquisition.
The DC and AC bus voltage imbalance measurements continued to
fluctuate. All other power-related measurements continue to reflect as
expected operation. A Tiger Team is investigating the AC/DC bus
voltage imbalance. To date, no credible single design or component
failure has been identified which could produce the observed anomalous
measurements. Furthermore, the team concluded based on flight data
and/or circuit analysis, that it is highly unlikely that the RTG, the
CDS interface measurement electronics, the CDS, or the PPS imbalance
sensor are the cause of the imbalance. Several other potential causes
are still being investigated including coupling between the AC and DC
power busses internal to the power subsystem and possible Spin Bearing
Assembly (SBA) contamination.
A total of 1,114 realtime commands have been sent since to the
spacecraft since launch; 192 were transmitted; of the 192, 51 were
preplanned as a part of the sequence design; 141 were not. Many of
the unplanned commands were associated with the issuance of
noninteractive instrument commands during the science checkout. This
two week period was the most active period of realtime commanding
since launch.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.95 | GALILEO Update - January 10 | RENOIR::KLAES | N = R*fgfpneflfifaL | Thu Jan 11 1990 13:18 | 56 |
| Newsgroups: sci.astro,sci.space
Subject: Galileo Update - 02/10/90
Date: 11 Jan 90 01:11:05 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
January 10, 1990
Today the Galileo spacecraft is 15.6 million miles from Earth;
round-trip light time is 2-3/4 minutes. It has traveled 128.5 million
miles along the first leg of its trajectory, with a current heliocentric
velocity of about 73,000 mph. The total trajectory distance traveled
will be 185 million miles at Galileo's Venus flyby February 9, 1990,
and 2.4 billion miles at Jupiter arrival December 7, 1995.
The spacecraft is in "dual spin" mode, with the upper part
spinning at 3.15 rpm and the lower part non-spinning with gyro-based
control. All temperatures and pressures are within acceptable limits;
telemetry is being sent via the second low-gain antenna (mounted below
a power generator boom) at 1,200 bits per second. The spacecraft
attitude sun point angle is 1.96 degrees.
Data from the four-day checkout of science instruments, concluded
December 30, are still being studied. Because of very high winds at
the Deep Space Network tracking station in Goldstone, California, some
data were lost during the checkout operations but not enough to
compromise the checkout. The heavy ion counter, magnetometer, dust
detector, ultraviolet and extreme ultraviolet instruments remain
powered on.
Some of the memory in the extreme ultraviolet instrument's
microprocessor was found to be corrupted; it was reloaded without
incident and the instrument is now operating nominally, and being
watched. Covers on the near-infrared mapping spectrometer (NIMS),
both ultraviolet instruments and the dust detector were removed on
schedule during the checkout. The infrared instrument appeared to be
cooling more slowly than expected after the cover was removed from its
cooling radiator. Yesterday a nearby heater, switched on earlier, was
turned off and the cooling rate improved. Based on this, it was
concluded that the NIMS radiator cover was fully deployed.
The AC imbalance measurements reached a level which indicated a
"hard" short chassis. The measurement remained at this level throughout
the tracking pass. The DC imbalance measurement continued to slowly
increase from about 20 volts to 20.6 volts and remained stable.
The spacecraft is normally executing the block of commands
designated Earth-Venus #5, which began Monday and will last until
February 5.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.96 | GALILEO Update - January 12 | RENOIR::KLAES | N = R*fgfpneflfifaL | Mon Jan 15 1990 15:02 | 138 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/12/90
Date: 13 Jan 90 18:27:55 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Mission Status Report
January 12, 1990
As of Friday, January 12, 1990, the Galileo Spacecraft is 16,229,650
miles from the Earth, 11,067,810 miles from Venus and was travelling at a
Heliocentric velocity of 73,900 miles per hour. Round trip light time is
2 minute, 52 seconds.
Two SITURNS to the Sun were successfully performed without incident
on January 9 and January 12. A total of 1151 real-time commands have been
transmitted to Galileo. Of these, 845 have been pre-planned in the
sequence design and 306 were not. In the past week a total of 61 real-time
commands were transmitted; 1 was pre-planned and 60 were not. To date a
total of 120 contingency commands have been generated and 4 contingency
commands have been transmitted; none were transmitted this week. This weeks
totals contain 10 commands from EV-05.
The EV-5 sequence memory load was successfully loaded into the CDS on
January 6. As part of the load process, elements 212 and 213 of the load
were not received initially and had to be retransmitted. Preliminary
analysis discovered the CDS had experience eight lock change indications
as detected by the HCD. Investigation into the cause of these lock changes
is in process by systems, CDS and telecom personnel. The EV-5 sequence
went into operation, as planned, on January 8. The events in EV-5 will
cover spacecraft activities through February 5.
As part of the investigation into the EUV microprocessor "stop"
anomaly, which occurred during the science checkout activity, the EUV
memory was loaded and readout twice on January 6. Subsequent to memory
verification, the EUV microprocessor was started on January 8. Memory
readouts were performed prior to and after the microprocessor start and
operation of the EUV was nominal. The exact cause of the anomaly which
stopped the microprocessor has not been determined. However, it is unlikely
based on this data that a "hard" failure has occurred in a 6504 memory chip.
The sixth RPM thruster "flushing" activity was successfully completed
on January 8. Only the Z, L and S thrusters were "flushed". Since the P
thrusters are used for periodic SITURNS they were not "flushed" during this
activity. The temperature profiles for the Z, L, and S thrusters were as
expected and ranged from a peak temperature of about 50 degree C to 100
degree C, well within the predicted limits.
A command was sent on January 9 to turn off the NIMS shield heater
(26W) for about 3 hours to permit the NIMS to collect Focal Plane Assembly
Temperature data in an attempt to ascertain whether the NIMS radiator
cover was deployed or not. After 3 hours, the heater was turned on again
consistent with RPM thermal/pressure constraints. Data collected by the
NIMS during the time the heater was off indicated the cover was either
already deployed or that it deployed as a result of the cool down possibly
relaxing any mechanical binding which may have existed.
The delta DOR function in the RFS was activated for the first time on
January 9. Delta DOR represents a navigation new data source in addition
to doppler and ranging data already available. Demonstration of the S-Band
delta DOR is being performed now while the RF link performance is still
"strong" and to allow sufficient time to understand and evaluate the DOR
data and its actual advantages to navigation. The S-Band delta DOR consists
on modulating the downlink carrier with a 3.82 MHZ sine wave. It is pointed
out that during the short periods that delta DOR is active, the telemetry
data stream from the Telemetry Modulation Unit is interrupted and no
spacecraft data is transmitted. Estimates indicate that a 2-3 kg fuel
savings post-Earth flyby is possible based on delta DOR data. The delta
DOR data analysis is in process and is expected to be available around
January 22.
The AC and DC bus imbalance measurements continued to fluctuate. On
January 9, the AC imbalance reached 48.4 volts indicative of a near "hard"
short to spacecraft chassis. The measurement remained stable for several
hours and subsequently dropped to about 40 volts. During this time while
the AC measurement fluctuated upward, the DC imbalance measurement very
slowly crept upward to 20.8 volts and remained stable (see Special Topic).
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL
The Project reviewed and approved the EV-6 Profile Design on January
12. EV-6 contains the Venus Encounter Sequence which starts one day before
the Venus closest approach and eight days later. Venus science data will be
recorded on the Data Management Subsystem (DMS). The equivalent of four
images will be returned using a technique incremental playback involving
transfer of small portions of recorded science data to the CDS then reading
out CDS memory.
This process will be done while the telecommunications leak is capable
of supporting the 1200bps downlink. Sequence and command generation starts on
January 15.
The Project approved the VE-1 and VE-2 Cruise Plans on January 11.
These sequences will cover spacecraft activities from February 19 to March 26
and from March 26 to April 23, respectively.
SPECIAL TOPIC
The fourth Tiger Team status report to the Project was held on January
10. Three major topics were covered. PPS reported that after careful review
of the inverter physical layout by LORAL engineers, it was concluded that
the physical spacings between AC and DC functions is large (approximately
30-100 mils) and that the "touching" of AC and DC power lines is very unlikely.
PPS will continue its effort to find any spacecraft event correlations with
the observed imbalance measurements.
Review of the Spin Bearing Assembly slip ring physical layout revealed
that there are several locations within the four modules where AC or DC or
grounds are adjacent. To determine the feasibility of a slip ring leakage
path, an intensive effort was initiated two weeks ago to develop a model.
The preliminary work to date indicates that it may be possible for small
particles of silver (less than 30 microns) to move under the influence of
electrostatic forces (causes by electric field gradients between adjacent
slip rings) and deposit across the barrier thereby creating a leakage path.
Work will continue on this model to refine the electrodynamic forces and to
generate two dimensional AC and DC electrostatic field diagrams.
Work has continued to determine the feasibility whether electrical noise
may be corrupting PPS sensor readings. Noise coupling models have been
developed and some stray current paths identified. Since stray currents may
produce erroneous readings in the PPS sensors, a careful review of all
spacecraft electrical loads is in process. Noise currents on the orbiter of a
few milliamperes may be sufficient to create anomalous readings.
The Project conducted a detailed review of its readiness and risk for
Venus Science. Assessments were provided by the OET, Sequence and Navigation
Teams of the Engineering Office; the Science Requirement and Ops Planning
Team representing the Science and Mission Design Office, the Flight Control
and Support Office and the Ground Systems Office. It was concluded that the
Venus Science encounter can be executed, in general, without adverse risk to
the spacecraft; the Flight Team is staffed and trained though there is no
margin in the development of the sequence. We are "GO" for Venus Science.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.97 | GALILEO Update - January 17 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Fri Jan 19 1990 13:14 | 46 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/17/90
Date: 18 Jan 90 18:51:23 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
GALILEO MISSION STATUS
January 17, 1990
Today the Galileo spacecraft is just under 18 million miles from
Earth, and 8.7 million miles from Venus. Round-trip light time to the
spacecraft is about 3.25 minutes. During the next week or so, there
will be an approximate line-up between the Sun, Venus, Galileo, Earth,
and Jupiter (Jupiter was at opposition two weeks ago, and the
spacecraft is several degrees above the ecliptic plane). Galileo has
rolled up 141 million miles around its orbit, at a velocity which has
increased to 75,600 mph, and with 44 million to go before Venus
encounter February 9 at 10 p.m. PST.
The health of the spacecraft is very good; it is in a "safed"
cruise mode following an incident Monday in which the attitude control
computer invoked system fault protection because of an incompatibility
found while performing a star calibration with the gyros off. The
flight team analyzed the incident quickly and are now working to
gradually restore various functions which were halted automatically
during the "safing" response. The spacecraft is spinning in all spin
mode at 2.89 rpm, and sending telemetry at 1200 bits per second.
On January 9, Galileo had its first demonstration of "Delta DOR,"
a Very Long Baseline Interferometry technique using two DSN stations
simultaneously to produce very precise angle tracking data. This will
be added to doppler and ranging to refine spacecraft navigation for
Earth and Jupiter encounters, to improve targeting while saving
propellant. The DSN's large antenna in Spain, DSS-63, has been down
for several weeks to replace a bearing. Repairs are progressing and
the antenna is expected to be operating in time for Venus encounter.
Last week the Project determined that no further trajectory
correction is needed for the Venus flyby; there will be no TCM-3.
Venus encounter and science will be part of the operating sequence
called EV-6, which will be effective February 5-18.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.98 | GALILEO Update - January 19 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Mon Jan 22 1990 19:47 | 88 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/19/90
Date: 20 Jan 90 02:28:50 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
JANUARY 19, 1990
As of Friday, January 19, 1990, the Galileo Spacecraft is
18,758,910 miles from the Earth, 7,862,150 miles from Venus and was
travelling at a Heliocentric velocity of 76,300 miles per hour. Round
trip light time is 3 minutes, 36 seconds.
A SITURN to the Sun was successfully performed without incident
on January 14. Spacecraft performance was nominal, as expected. A
total of 1221 real-time commands have been transmitted to Galileo. Of
these, 846 have been pre-planned in the sequence design and 375 were
not. In the past week a total of 70 real-time commands were
transmitted; one was pre-planned and 69 were not. Major activities
this week included: (1) turning on the Bay B Replacement Heater and
(2) the Star Scanner B calibration and its subsequent anomaly
investigation and data rate correction.
With the beginning of DSN tracking coverage on January 15 at 0730
PST, evidence of an AACS mode change was discovered when telemetry
indicated the AACS autonomously had transitioned from the inertial
mode (used for the SITURN on January 14) to the cruise mode.
"Immediate" review of other AACS telemetry data showed error
indications in both the inertial observer and rotor attitude
estimation algorithms. The rotor attitude estimation algorithm uses
only star-based data to generate an attitude estimate based on SEQID.
This estimate is then used by the inertial observer algorithm to
update the rotor attitude estimate generated by the gyros. It is
pointed out that to transition from inertial to cruise mode requires
that the inertial observer "new" gyro-based attitude estimate differ
from the "old" gyro-based estimate by > three degrees for four
consecutive compare periods (about 20 seconds for the star set in
use). Review of rotor attitude estimate data showed a large number of
error counts possibly indicating concerns for the star set being used
during this phase of the mission. One speculation is the star scanner
may be "seeing" some interleaved stars, i.e., several stars of
acceptable intensity which are geometrically close together thereby
producing extra star pulses. Since no fault response action is taken
as a result of anomalous rotor data estimates based on the rotor
attitude algorithm, the inertial observer initiated the fault
response. AACS personnel are vigorously working this problem to
determine the cause and potential solution.
Several realtime commands were sent during the evening on January
15 to reconfigure the downlink telemetry rate back to 1200bps to
maximize telemetry visibility, to trim the power margin for RPM, and
to perform memory readouts of selected locations in AACS and CDS. As
of today the spacecraft still remains in the "safed" condition
executing Sun acquisitions every 12 hours.
It is pointed out that to accommodate the necessary actions
mentioned above and to monitor the spacecraft performance for the
first time in the "safed" state, DSS-43 tracking coverage was diverted
from Pioneer 11 (for 1 hour) and Voyager 2 (for 5 hours).
Realtime commands were sent on January 19 to reset the AACS
catastrophe handler flag to avoid the execution of the "heartbeat"
loss algorithm in response to a subsequent AACS faults affecting the
SBA, SAS, DEUCE, Star Scanner, I/O or thruster configuration.
Execution of "heartbeat" loss is very traumatic and can result in
numerous AACS hardware reconfigurations including processors and
memories and if executed to completion results in about 70 to 80 AACS PORs.
All EV-5 sequence activity was cancelled as a result of executing
the system spacecraft safing algorithms. An immediate review of the
EV-5 sequence events was performed and it was concluded that there was
no concern for spacecraft health or mission events due to cancelling
the EV-5 sequence. It is pointed out that the EV-5 sequence would have
been operative through February 5.
The Project reviewed and approved the spacecraft recovery plan on
January 19. To minimize risk and allow the longest available time for
the recovery process, the EV-5 sequence will not be restarted.
Several events such as RPM flushing, SSI power turn-on/health check,
gyro updates, etc. will be performed via realtime commands.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.99 | GALILEO Update - January 25 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Fri Jan 26 1990 13:26 | 34 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/25/90
Date: 26 Jan 90 00:00:28 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
January 25, 1990
The Galileo spacecraft is about 21.5 million miles from Earth
today, and 5.4 million miles from Venus. Round-trip light time to the
spacecraft is almost 4 minutes. Galileo has traveled almost 156
million miles since launch in its orbit around the Sun, and has
reached an orbital velocity of more than 78,000 miles per hour.
The spacecraft is in very good health, operating in its all- spin
"safe" mode with automatic sun-pointing. All science instruments
except the dust detector are turned off, and the spacecraft is
spinning at a rate of 2.89 rpm, pointed within 1/2 degree of the Sun
base on the acquisition sensor. It is sending telemetry at 1200 bits
per second over the low-gain antenna as usual. The DC bus imbalance is
at 20.59 volts and the AC bus imbalance is at 48.75 volts.
The flight team is continuing the orderly step-by-step process of
returning Galileo to a cruise configuration and preparing it for the
Venus science observations scheduled for early next month. DSS-63,
the 70-meter tracking station in Spain, completed its repairs this week
and successfully performed a Galileo telemetry and tracking pass today.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.100 | GALILEO Update - January 26 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Mon Jan 29 1990 17:30 | 75 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/26/90
Date: 26 Jan 90 23:44:52 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
JANUARY 26, 1990
As of Friday, January 26, 1990, the Galileo Spacecraft is
22,009,750 miles from Earth, 5,065,800 miles from Venus (.769 AU)
and was travelling at a Heliocentric velocity of 78,960 miles per
hour. Round trip light time is 3 minutes 58 seconds.
The spacecraft remains in a "safed" condition and has
successfully performed more than 20 automatic sun acquisitions (every
12 hours) since execution of the spacecraft safing algorithms on
January 15.
The second and last RTG temperature measurement, mounted on the
+x RTG, made an abrupt change on January 22 indicating an open circuit
somewhere between the temperature transducer and the CDS input. Other
measurements routed into this CDS tree-switch were monitored for any
anomalous/unexpected readings; none have been detected. The loss of
these two temperature measurements does not pose a threat to the RTG
or the spacecraft since power performance parameters (V, I) are
measured separately. It is pointed out that each RTG measurement is
separately dedicated and routed to each half of the CDS.
As a continuing part of the spacecraft recovery process, a series
of commands were sent on January 26 to power-off selected engineering
and science heaters and to power on the UVS, HIC, MAG and EUV
instruments consistent with the expected spacecraft state at the end
of EV-5.
The replacement and checkout of the DSS-63 failed elevation
bearing has been completed. The 70-meter tracking station in Spain
completed its repairs and checkout this week and successfully
performed a Galileo telemetry and tracking pass on Thursday, January
25, 1990.
SPECIAL TOPIC
The Bus Imbalance Tiger Team continued its effort to develop a
feasibility model which could support a supposition that spin bearing
slip ring debris may be the cause of the observed bus imbalance.
Using debris collected during slip ring module life tests, preliminary
electrical tests in air showed that it is possible for small currents
(hundreds of microamperes) to flow when debris is configured to form a
conductive path between a 30 VDC power supply and chassis ground.
Currents greater than about 300 microamperes were large enough to
"open" the circuit and stop current flow. Further test will be
conducted this week under vacuum conditions to determine whether
higher currents are possible and can they be sustained. It is pointed
out that for this debris model to be the cause, it is necessary that
roughly 30 times more debris would have to be generated by the flight
slip rings in the SBA than the levels observed during the life test.
Another model was presented which postulated that a single
capacitor failure in the PPS electronics could cause both the AC and
DC anomalous readings. The basic idea is that stray currents caused by
electrical noise created by the on/off switching in the 2.4 KHz
inverter is being sensed by both bus imbalance detectors. Preliminary
computer modeling performed showed that simulated sensor readings may
exhibit the erratic behavior observed in flight. Further work on this
electrical model will continue to better understand the circuit
parameters, their correlation with actual physical layouts and the
failure modes of the capacitor.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.101 | Strange analogy | DECWIN::FISHER | Burns Fisher 381-1466, ZKO3-4/W23 | Mon Jan 29 1990 18:49 | 22 |
| re .99:
> The spacecraft is in very good health, operating in its all- spin
>"safe" mode with automatic sun-pointing. All science instruments
>except the dust detector are turned off, and the spacecraft is
>spinning at a rate of 2.89 rpm, pointed within 1/2 degree of the Sun
>base on the acquisition sensor. It is sending telemetry at 1200 bits
>per second over the low-gain antenna as usual. The DC bus imbalance is
>at 20.59 volts and the AC bus imbalance is at 48.75 volts.
Does this remind anyone vaguely of our latest quarterly report?
"DEC REPORT INCREASE IN REVENUE"
(of about $1 total, but earnings dropped majorly).
The Galileo status report says, "Health is VERY GOOD" except for some major
emergencies have left the spacecraft still in an automatic safe mode.
(Makes you wonder how Phobos I and II got as far as they did without this kind
of auto-fallback stuff, doesn't it?)
Burns
|
| 560.102 | GALILEO to flyby Venus on February 10 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Tue Feb 06 1990 18:06 | 134 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/31/90
Date: 1 Feb 90 02:06:12 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
January 31, 1990
The Galileo spacecraft is almost 25 million miles from Earth
today, with a round-trip light time of almost 4+ minutes; distance to
Venus is down to 3 million miles. The length of the journey since
launch has reached 167 million miles, and the velocity relative to the
Sun is up to 80,525 miles per hour.
General health of the spacecraft continues to be very good, with
a nominal power margin and all temperatures in the acceptable range.
It continues in a all-spin configuration (2.89 rpm, Sun-pointed within
1/2 degree), sending telemetry over low-gain antenna 2 at 1200 bits
per second. Galileo continues to operate in a caretaker mode,
automatically maintaining sunpoint. In addition to the dust detector,
Galileo's magnetometer, heavy ion counter, and ultraviolet instruments
have been turned on.
A star scanner spin rate estimate failed once during a S-thruster
flushing activity. Preliminary analysis indicates that the scanner may
have "seen" several stars of near equal intensity, therefore "seeing
too many stars" in the field-of-view.
The flight team has developed the sequence which will control
Galileo through the Venus flyby (actually, through the period February
7-18). In addition, work is well underway on the first post-Venus
cruise sequence.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/02/90
Date: 5 Feb 90 22:28:35 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
FEBRUARY 2, 1990
As of Friday, February 2, 1990, the Galileo Spacecraft is
26,043,650 miles from Earth, 2,563,520 miles from Venus and is
travelling at a Heliocentric velocity of 81,222 miles per hour.
Round trip light time is 4 minutes, 36 seconds.
The recovery activity to reconfigure the spacecraft to a state
for the Venus flyby is proceeding well. A total of 74 state changes
are required to get into the EV-6 initial state. More than 50 percent
of the state changes have been accomplished to date; the remainder
will be completed by February 6.
The spacecraft remains in the all-spin mode and has completed
nearly 40 automatic sun acquisitions (every 12 hours) since execution
of the spacecraft safing algorithms on January 15.
The seventh RPM thruster "flushing" activity was successfully
completed on January 29. The activity normally scheduled as a part of
EV-5 was cancelled when the spacecraft executed the safing algorithms.
The activity was performed using real-time commands and only the Z, L
and S thrusters were "flushed". Since the P-thrusters are used for the
routine sun acquisitions they were not "flushed" during this activity.
The temperature profiles for the Z, L and S thrusters were as
expected and ranged from a peak temperature of about 69 degree C to
100 degree C, well within the predicted limits.
A star scanner "A" calibration was successfully completed on
February 1. This calibration was performed to collect star data to aid
with the investigation into the inertial to cruise transition anomaly
which occurred in mid-January.
The AC/DC bus imbalance measurements have remained relatively
stable for the last 2 to 3 weeks. The DC measurement has fluctuated
about 1 volt between about 19.6 volts and 20.7 volts and the AC
measurement has fluctuated about 5 volts between 43.8 and 48.7 volts.
Review of imbalance measurement data prior to and after entry into the
spacecraft safing did not reveal any significant measurement
differences between dual-spin/all-spin operation.
The first celestial reference acquisition activity since
spacecraft safing execution was successfully completed on February 2
after the automatic Sun acquisition via the Sun point algorithm. For
this activity, the spacecraft was in a Sun-pointed attitude, in
all-spin mode and Sun-pointed stars were acquired with SEQID
converging as expected. The successful completion of this SEQID was
an important event in the spacecraft recovery process for the Venus
flyby. Other crucial near-term attitude control events include a gyro
parameter update planned for February 3 (based on data collected
during the minical). This update is expected to reduce scan platform
pointing errors from about 5 mrad to 1 mrad.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/06/90 (Forwarded)
Date: 6 Feb 90 17:17:08 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO VENUS FLY-BY
February 6, 1990
NASA's Galileo spacecraft will fly by planet Venus at about 1
a.m. EST, Sat., Feb. 10, 1990, on the first leg of its gravity-
assisted flight path to planet Jupiter. Galileo will record
scientific observations for playback in October. There will be no
live or real-time science from this Venus fly-by.
Galileo Project Manager Dick Spehalski will present the latest
status updates on the trajectory, the spacecraft and its instruments
at a press briefing at noon EST, Feb. 10, from JPL. The briefing will
be carried live on NASA Select TV, Satcom F2R, Transponder 13, at 72
degrees W. Longitude. Project Scientist Torrence Johnson and Mission
Design Manager William O'Neil also will participate in the briefing.
The NASA Headquarters sixth floor auditorium, 400 Md. Ave., S.W.,
will be open during the press briefing.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.103 | GALILEO Update - February 7 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Wed Feb 07 1990 21:15 | 79 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/07/90
Date: 7 Feb 90 20:21:47 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
February 7, 1990
Today the Galileo spacecraft is 29.4 million miles from Earth;
round-trip light time is 5 minutes 16 seconds. It has rolled up
almost 181 million of the 185 million miles around its orbit from
launch last October to the Venus flyby, which occurs Friday night (a
minute before 10 p.m. PST, or about 1 a.m. EST). Heliocentric velocity
has now reached about 83,000 mph.
The Venus gravity-assist flyby will bring the spacecraft about
10,000 miles above the cloud-tops, 41 degrees south of the planet's
equator. Galileo will cross behind Venus, increase its velocity by
about 5,000 mph, and take up a different, slightly larger solar orbit
which comes within 65 million miles of the Sun on February 25 and then
curves out to fly by Earth in December for its second gravity assist
at a 600-mile altitude.
During the Venus flyby, the spacecraft will record about 80
images and many other scientific observations for playback in late
October when the telecommunications link can support the 7.68-kilobit
science data rate.
The spacecraft continues in excellent health; the power margin
and spacecraft temperatures are as expected. Galileo is in normal
cruise mode, with part of the spacecraft despun and the rest spinning
at 3.15 rpm. The telemetry rate is 1200 bits per second, radiating
from low-gain antenna No. 2. The spacecraft attitude sun point angle
is at 2.6 degrees. The first part of the Venus flyby operational
sequence was transmitted up yesterday (and is now active aboard
Galileo); the rest is to be sent up tomorrow.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
Newsgroups: sci.space,sci.astro
Subject: Galileo Mission Schedule
Date: 7 Feb 90 20:28:22 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Schedule
10/18/89 - Launch from Space Shuttle
02/09/90 - Venus Flyby
10/**/90 - Venus Data Playback
12/08/90 - 1st Earth Flyby
05/01/91 - High Gain Antenna Unfurled
07/91 - 06/92 - 1st Asteroid Belt Passage
10/29/91 - Asteroid Gaspra Flyby
12/08/92 - 2nd Earth Flyby
05/93 - 11/93 - 2nd Asteroid Belt Passage
08/28/93 - Asteroid Ida Flyby
07/02/95 - Probe Separation
07/09/95 - Orbiter Deflection Maneuver
12/95 - 10/97 - Orbital Tour of Jovian Moons
12/07/95 - Jupiter/Io Encounter
07/18/96 - Ganymede
09/28/96 - Ganymede
12/12/96 - Callisto
01/23/97 - Europa
02/28/97 - Ganymede
04/22/97 - Europa
05/31/97 - Europa
10/05/97 - Jupiter Magnetotail Exploration
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.104 | GALILEO Update - February 9 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Mon Feb 12 1990 16:46 | 86 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/09/90
Date: 9 Feb 90 23:57:58 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
FEBRUARY 9, 1990
As of noon Friday, February 9, 1990, the Galileo Spacecraft
is 30,906,100 miles from Earth, 206,700 miles from Venus and is
travelling at a Heliocentric velocity of 83,721 miles per hour.
Round trip light time is 5 minutes, 26 seconds.
Several crucial spacecraft recovery events were planned to occur
during the past week including celestial reference acquisition
(SEQID), updating gyro parameters based on December minical data and
a SITURN to lead the Sun. All these events were successfully
accomplished on February 2, 3 and 4, respectively.
Commands were sent on February 5 to reconfigure several
spacecraft electrical loads to create sufficient power margin to allow
safe power-on of the SSI instrument and still maintain a safe overall
system power margin.
The first part and second part of the EV-6 sequence memory load
were both successfully transmitted and received by the spacecraft
without incident on February 6 and February 8, respectively. The EV-6
sequence covers spacecraft activities from February 7 through February 18.
Commands were sent on February 6 to power off the NIMS
replacement heater and power on the NIMS instrument. This action was
taken, after interaction with the Principal Investigator (PI), in
response to a perceived low temperature condition (zero DN reading) in
the Focal Plane Assembly (FPA). The perceived temperature may have
dropped to near 60 degree K before action was taken. This temperature
is lower than those experienced in ground based testing. However, the
PI's preliminary assessment was that this low temperature condition
did not pose a threat to the instrument. About 18 hours after
instrument power on, the FPA temperature reached 65 degree K, closer
to its flight of allowable lower limit of 70 degree K.
A set of commands were sent on February 8 to update the Venus
flyby star set, enable bright body fault protection, and for a limited
period (about 2.5 hours) close the star scanner shutter to protect the
scanner from possible Venus bright body induced damage. During the
Venus flyby phase, if attitude reference is lost, it is possible that
Venus, a bright body, could be observed by the star scanner;
therefore, to protect the scanner vector bright body avoidance fault
protection was enabled for a period of about 21.5 hours during the
flyby period. In addition, planned closure of the star scanner
shutter for about 2.5 hours near closest approach was performed to
protect the scanner from possible damage caused by expected "Venus
light" entering the scanner stray-light field-of-View (>52degree).
Subsequent to the 2.5 hour period, the shutter was reopened and stars
reacquired. Prior to implementing this strategy, detailed analysis
and testing was performed to evaluate the attitude control performance
under both nominal and simulated fault conditions; no surprises,
anomalies or problems were observed.
A set of commands were sent on February 7 and 8 to perform EUV
and DDS memory readouts to return stored science data. Other commands
were sent on February 8 to put the EUV instrument into a science data
taking mode consistent with Venus data collection.
During the closest approach phase, science data will be collected
from instruments and stored on board in the tape recorder for
subsequent playback. Due to telecommunications performance (1200 bps
maximum rate), no science data will be returned in real time. Early
next week, however, some limited amount of Imaging, NIMS and other
science data will be returned to Earth via a special technique (called
DMS MRO) which plays back the tape recorder into the CDS and then data
is telemetered to Earth at 1200 bps.
The AC/DC bus voltage imbalance measurements have remained
relatively stable and have fluctuated only slightly between 45 and 48
volts (AC) and 18.5 and 21 volts (DC). Review of data covering the
transition from all-spin back to dual-spin (cruise and inertial)
operation did not reveal any significant measurement differences.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.105 | | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Mon Feb 12 1990 19:20 | 15 |
| The flyby was successful, with the spacecraft travelling a few
kilometers (less than 10) closer to Venus than planned and the course
change occuring as planned.
Post encounter telemetry indicated that many more shutter events on the
solid state imager had occured than expected. As of Saturday they were
not sure why but a news item this morning implied that whatever
problem, if any, had been fixed. Galileo is due to take a couple of
images today and then relay them to Earth. Several images were taken
during approach of the dark side of Venus (looking for lightning) but
they will not be replayed until later this year when the high gain
antenna can be used. Current data rate is 1200 bps. The delay also
minimises wear on the onboard recorder.
gary
|
| 560.106 | GALILEO Update - February 12 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Tue Feb 13 1990 12:26 | 43 |
| Date: 12 Feb 90 23:27:12 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@lll-winken.llnl.gov
(Ron Baalke)
Subject: Galileo Update - 02/12/90
GALILEO MISSION STATUS
February 12, 1990
The Galileo spacecraft is 33.4 million miles from Earth, 818,000
miles from Venus, and 450 million miles from Jupiter today. The Venus
flyby occurred as predicted about a minute before 10 p.m. PST Friday,
10,000 miles above Venus (41 degrees south of the equator). The
spacecraft gained 4,990 mph from the gravity assist as planned.
The spacecraft is currently in excellent health; the latest
imaging session concluded about 6 a.m. (PST) today, and the next is
due about 10 p.m.
The special circumstances which induced an onboard computer to
send the imaging system a series of unplanned shuttering commands
early Saturday morning are now fully understood and will not occur
again. The anomaly resulted in about 760 unplanned shutter activities
before the sequence control shuttering ended. The flight team began
analyzing these circumstances soon after turning off the camera
Saturday morning and were able to turn it on again safely in time for
the next scheduled imaging session Saturday night. They determined
that a minor incompatibility between the spacecraft's main computer
software control timing and ground memory management system caused the
anomaly; there were no hardware problems and no damage, and no extra
pictures were recorded on tape. There is high confidence that 14 of
16 planned images expected in this phase were properly executed.
At the moment the spacecraft is not being tracked by the Deep
Space Network; the Australian station's pass ended this morning,
shortly after the imaging session concluded, and the station in Spain
will pick up Galileo this evening, a few hours before the next imaging
activity is due.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.107 | GALILEO Update - February 16 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Tue Feb 20 1990 13:49 | 96 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/16/90
Date: 20 Feb 90 04:48:00 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
FEBRUARY 16, 1990
As of noon Friday, February 16, 1990, the Galileo spacecraft is
36,987,350 miles from Earth, 2,151,150 miles from Venus and is
traveling at a Heliocentric velocity of 90,063 miles per hour.
Perihelion will occur on February 25. Roundtrip light time is 6
minutes, 30 seconds.
Venus flyby was successfully accomplished late on February 9, 1990.
Radio tracking data indicated the delta velocity achieved by the
gravity assist was as expected. The spacecraft velocity was increased
by nearly 5,000 mph. Spacecraft performance during the flyby was as
expected and within predicted values.
During the post-Venus closest approach phase, an apparent anomaly
occurred involving the Solid State Imaging system (SSI). The anomaly
resulted in several hundred (approximately 760) unplanned SSI shutter
actuations. CDS and SSI memory readouts were performed and
subsequently the SSI was powered-off and its replacement heater
powered-on to assure the health and safety of the instrument.
Intensive anomaly investigation was initiated. Later that day mission
and spacecraft risk assessment by the Project personnel concluded it
was safe to power-on the SSI again and continue with the imaging
sequence planned for late February 10th. Careful review of the anomaly
timing indicates there is high confidence that 14 of 16 images planned
during this phase were properly executed.
The SITURNS to lead the sun by about two degrees were
successfully completed on February 10, 13 and 15.
Part B of the EV-6 sequence memory load went active as planned on
February 12. This EV-6 memory load contains the spacecraft events
needed to accomplish the DMS MRO activity. It is pointed out that the
DMS MRO is a special experimental technique which basically plays back
the stored tape recorder data into the CDS at 7.68 kbps and then data
is transmitted to Earth at 1.2 kbps consistent with the telemetry link
performance. Since a single compressed image being returned contains
a little over 3 x 106 bits and the imaging data is transmitted to
Earth at 256 bits/sec. (imaging data portion of the 1.2 kbps), the
time to retrieve a picture from the telemetry standpoint only is
roughly 3.6 hours.
The DMS MRO activity began as scheduled on February 13. To
maximize the downlink performance, the spacecraft's S-Band ranging
channel was turned off and the DSN diplexer was bypassed (station is
listen-only mode) thereby improving the performance margin by about
1.8 db.
The Venus-Earth 1 sequence memory load was transmitted and
properly received by the spacecraft without incident on February 16.
The VE-1 sequence controls spacecraft activities from February 19
through March 26. This sequence includes two major first time events
such as Low Gain Antenna (LGA) LGA-2 to LGA-1 switch and downlink
telemetry operation at 10 bps.
The AC/DC bus imbalance measurements profile during this last
week was not much different from that observed for the last three
weeks. The AC measurement continued to fluctuate between about 45 and
48 volts (AC) and about 19 and 21 volts (DC).
The GDS successfully supported the Venus Encounter and subsequent
playback of selected data from the spacecraft tape recorder via CDS
Memory Read Out (MRO). Support of MRO operations required manual
reconfiguration of the Deep Space Network (DSN) telemetry system at
the tracking stations for each of the frequent spacecraft data rate
changes (twice every 45 minutes). The DSN NOCC and tracking station
operations personnel are to be commended for excellent "heads-up"
operational support that was able to accomplish the required
reconfigurations with no loss of playback data. The two significant
GDS problems occurring during Venus support were as follows:
1. An error in CDS sequencing memory management (generated by the
SEQTRAN program) for the Venus sequence caused parameters for the SSI
control Spacecraft Expanded Block (SEB) to be overwritten before CDS
execution of the block was complete.
2. Playback of the selected images over the 70 meter antenna in
Goldstone on Tuesday was interrupted when high winds forced stowing of
the 70 meter antenna. About one-half of the first image was lost
(temporarily since it will be played back later). A 34 meter antenna
in Australia was called from a Pioneer pass (at rise time) to provide
Galileo support in time for playback of the remaining two images.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.108 | Images from tape? | ROYALT::WALL | | Wed Feb 21 1990 15:13 | 7 |
|
Does anybody know when they will be showing the images played back from
the tape recorder?
Sean
|
| 560.109 | | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Wed Feb 21 1990 18:59 | 8 |
| They have already transmitted the three or so pictures that they took
after closest Venus encounter. One of them is in this week's AvLeak.
The others that were taken as Gallileo approached Venus will not be
transmitted until it approaches Earth this December when they will dump
all of the recorded data from the Venus encounter.
gary
|
| 560.110 | GALILEO Update - February 23 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Mon Feb 26 1990 14:15 | 77 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/23/90
Date: 24 Feb 90 04:09:01 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
FEBRUARY 23, 1990
As of noon Friday (PST), February 23, 1990, the Galileo
spacecraft is 43,558,340 miles from Earth, 4,474,870 miles from Venus
and is traveling at a Heliocentric velocity of 90,700 miles per hour.
Perihelion will occur on February 25. Round trip light time is 7
minutes, 40 seconds. Galileo is in cruise mode-dual spin with a spin
rate of 3.15 rpm as measured by its star scanner. The spacecraft's
attitude sun point angle is at 1.9 degrees. A total of 1746 real-time
commands have been transmitted to Galileo sinced its launch on October 18.
The Venus Earth (VE-1) stored sequence became active on February
19, as planned. This sequence controls spacecraft activities from
February 19 through March 26.
A total of four SITURNS were successfully performed without
incident on February 17, 19, 20 and 22. The SITURNS during this
mission phase are nominally planned to lead the sun by about 2.3
degrees.
The telemetry downlink data rate was successfully configured to
40 bps coded, as planned. It is pointed out that the available
telemetry rate for all activities between February 17 and March 6 will
be at 40 bps. In fact, between March 6 and March 26 (near the end of
VE-1 sequence), the telemetry data rate must further be reduced to 10
bps in order to maintain the required link Bit Error Rate (BER) based
on predicted telemetry link performance.
The eighth RPM thruster "flushing" activity was successfully
completed on February 21. The activity "flushed" the Z, L and S
thrusters only. The P-thrusters were not flushed since they are used
to perform the SITURNS. Unlike previous "flushing" activities, the
thruster temperature profiles for the Z, L and S thrusters were not
available due to the low sample frequency associated with the 40 bps
downlink telemetry data rate. It is pointed out that successful
"flushing" activity was inferred from other spacecraft
measurements/events, including attitude control performance and
thruster counts.
Telecommunication system elements characterization tests
involving the Command Detection Unit (CDU) and elements of the Radio
Frequency Subsystem (RFS) were successfully performed, as planned on
February 21 and 22; no anomalies or surprises were observed.
Spacecraft temperatures/pressures are all well within acceptable
ranges as the spacecraft nears perihelion on February 25; no concerns
for any hardware have been identified. The three fields and particles
instruments (PWS, EPD and PLS), which expressed some limited thermal
concern, were powered off, as planned, post-Venus Encounter and are
expected to be thermally safe through perihelion.
Science memory readout (MRO) for the DDS, MAG and EUV instruments
was successfully performed, as planned. Periodic MROs allow selected
cruise science data to be returned to Earth expeditiously despite the
present low telemetry data rate capability.
The AC/DC bus imbalance measurements have remained stable. The AC
imbalance measurement (48.75 volts) has indicated a "hard" short from
the low side to chassis for the last three days. The DC imbalance
measurement has remained relatively stable varying between 21 and 21.3
volts. It is pointed out that other power-related telemetry
measurements (bus voltages, bus load currents, shunt current) and
subsystem engineering telemetry measurements are as expected.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.111 | GALILEO Update - February 28 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Fri Mar 02 1990 12:34 | 51 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/28/90
Date: 1 Mar 90 23:48:55 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
February 28, 1990
The Galileo spacecraft is 48.4 million miles from Earth today;
this distance is still increasing, and will for the next three months,
even though the trajectory leads toward an encounter with Earth in
December. Round-trip light time is 8 minutes 41 seconds. The
spacecraft passed through perihelion (closest to the Sun) February 25.
Galileo has now gone 226 million of the 2.4 billion miles along its
looping 6-year path to Jupiter.
Health of the spacecraft remains excellent; it is in dual spin,
performing some cruise science data collection and engineering
maintenance functions such as sun-pointing maneuvers. The telemetry
rate is 40 bits per second; about March 6 this will go to 10 bits per
second consistent with communications link capability. Galileo's
activities are controlled by an onboard-stored program or flight
sequence activated February 19 and due to run through March 26.
Galileo is now committed to encountering the Gaspra asteroid.
The propellant margin estimate is at a negative 17.6 pounds with a
90% confidence. Galileo's thrusters are about 2% more efficient than
expected. The decision to proceed to the Ida asteroid won't be made
until after the Gaspra encounter.
Galileo's two ultraviolet spectrometers have shown that hydrogen
atoms at Earth's distance from the Sun last about 1 million seconds
(almost 12 days) before ionizing. Also, Galileo is already reporting
on the ultraviolet spectra of the star Kappa Velorum and on impacts
by space dust. The largest piece yet detected weighed about one
hundred-millionth of a gram and measured about 26 microns across.
The next sequence, to run through April 23, is being processed
and reviewed by the flight team. Like the current one, the next
sequence will include spacecraft maintenance activities and some
cruise science observations; it also includes the first portion of
the trajectory correction maneuver to help shape the flight path for
December's Earth gravity-assist flyby, next step in propelling Galileo
to Jupiter.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.112 | GALILEO Update - March 5 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Tue Mar 06 1990 13:33 | 88 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/05/90
Date: 5 Mar 90 21:39:35 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
MARCH 5, 1990
The Galileo spacecraft is 50,374,030 miles from Earth, 6,720,180
miles from Venus and was travelling at a Heliocentric velocity of
90,480 miles per hour. Galileo is in cruise mode-dual spin with a
spin rate of 3.15 rpm as measured by its star scanner. The spacecraft's
attitude sun point angle is at 0.5 degrees. Perihelion occurred on
February 25. Round trip light time is 8 minutes, 54 seconds.
Several SITURNS to lead the sun were successfully performed on
February 24, 26, 28 and March 2. Subsequent to the SITURNS performed
on February 24 and 26, the attitude control system successfully
completed a planned spin detector calibration. This calibration
activity commanded the spacecraft from the initial dual-spin mode to
all-spin and then back to dual-spin. The spacecraft performance was as
expected throughout the calibration activity.
Several changes were made to the star sets already on board in
the Venus-Earth-1 (VE-1) sequence load. Changes were made to star sets
on February 28 and March 2 to maximize the likelihood of successful
star acquisition. The star updates were made after attitude control
identified serious concern with the on-board star set. Prior to
loading the new stars, extensive analysis and testing was performed.
Attitude control star analysts have completed testing of the remaining
stars in VE-1 beyond March 6. All tests were successful; no further
star updates in VE-1 are required.
Commands were sent on February 26 to change the attitude control
parameters associated with the star scanner bright body avoidance. The
parameter change reduces the half-cone angle stray-light field of view
from about 50 degrees (set at Venus) to about 30 degrees. This change
allows the star scanner to safely and reliably detect the required
stars in the remainder of the VE-1 sequence through March 26.
On February 26 the system fault protection software was changed
to command selection of the Low Gain Antenna-1 (LGA-1) in the event of
execution of the command loss algorithm. Actual switch from LGA-2 to
the LGA-1 is scheduled for March 12. Performance over the LGA-1 is
acceptable for both command and telemetry as early as March 9.
Telemetry performance will be limited to 10 bps from March 6 thru
March 25.
Cruise Science memory readouts were successfully performed for
the EUV, DDS and MAG instruments as planned.
AC/DC bus imbalance measurements remain relatively stable. The AC
measurement has varied between 47 and 48.5 volts while DC measurement
has varied between 21.3 and 21.6 volts. All other power-related
measurements (bus voltages, currents, shunt current) and other
subsystem measurements have all been as expected.
On February 24 the Command and Data Subsystem (CDS) telemetry
indicated that a despun Critical Controller (CRC) Power on Reset (POR)
had occurred. No similar indications were evident elsewhere in the
CDS. In fact, all other CDS telemetry indicators were as expected. The
POR signal is generated by the CDS power converter and sent to the
corresponding Hardware Command Decoder (HCD), and/or spun and despun
Critical Controller Circuitry (CRC). The POR signal is normally
generated when either power converter detects a low voltage condition
for several tens of microseconds. No interruptions in processing or
loss of functionality were observed. Once a despun CRC POR indication
is received the logic circuity in the CDS holds that state (via a
latch device) until it is reset by ground command.
Upon completion of initial anomaly analysis, several real-time
command troubleshooting actions were taken on February 28 and March 2
to determine whether the POR signal was still present and to reset the
POR bit. The first action verified that the CRC POR bit was still
"set" as expected. The subsequent actions on March 2 POR successfully
reset the POR bit and that the POR related logic circuitry is
functioning properly. The success of these actions provides confidence
that the critical controller circuity and telemetry circuits which
monitor this function are working properly. The exact cause of this
anomaly is unknown and its implications are presently being assessed.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.113 | GALILEO may help determine meteorite origins | WRKSYS::KLAES | N = R*fgfpneflfifaL | Tue Mar 06 1990 14:18 | 25 |
| From: henry@utzoo.uucp (Henry Spencer)
Newsgroups: sci.space,sci.space.shuttle
Subject: Space news from January 29 AW&ST, etc.
Date: 6 Mar 90 04:30:10 GMT
Organization: U of Toronto Zoology
[From the February 2 issue of SCIENCE:]
The standard explanation of meteorites is that they are debris
from the asteroids. This is convenient in that it gives us samples of
asteroidal material, albeit very poorly documented ones. The most
common type of meteorites, the ordinary chondrites, are thought to be
derived from the common type S asteroids. The material in ordinary
chondrites seems to be primitive material from the early solar system,
never exposed to major heating. Unfortunately, the spectroscopists
have announced strong evidence that the type-S asteroids are too
metal-rich to be primitive bodies in general, and to be the source of
the ordinary chondrites in particular. Confusion reigns: Where can
the ordinary chondrites possibly be coming from? There is some hope
that the first GALILEO asteroid encounter, with Gaspra in Aug. 1991,
might shed some light on asteroidal geology: Gaspra is type S.
Henry Spencer at U of Toronto Zoology
uunet!attcan!utzoo!henry henry@zoo.toronto.edu
|
| 560.114 | GALILEO Update - March 6 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Wed Mar 07 1990 19:53 | 37 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/06/90
Date: 7 Mar 90 19:57:25 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
MARCH 6, 1990
Today the Galileo spacecraft is 54.3 million miles from Earth,
65.6 million from the Sun, going almost 90,000 mph in its solar orbit.
It has rolled up 239 million miles in space since launch last October 18.
The spacecraft health continues to be excellent, and the program
of activities continues to be rather quiet. Galileo is doing a
sun-point maneuver every other day. These maneuvers are part of the
current operational sequence. After each one, Galileo's star scanner
looks at a slightly different circle of stars to verify its pointing
and spin rate. The flight team has checked and updated the star maps
carried in spacecraft memory, to be sure the onboard computers (which
estimate attitude and spin rate) have good inputs. They also
completed a calibration of the spin detector, a centrifugal sensor
providing redundant spin-rate data, backing up the star scanner,
gyros, and acquisition sun sensor for this purpose.
The spacecraft is also performing selected "cruise science"
measurements of certain fields and particles, at a low level of
activity (compared to a planetary flyby). Galileo's telemetry rate
is limited by the distance and angle of Earth to 10 bits per second
(the lowest) from today through March 25. Galileo will switch Low Gain
Antennas on March 12.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.115 | GALILEO Update - March 9 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Sun Mar 11 1990 15:10 | 61 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/09/90
Date: 10 Mar 90 01:49:49 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
MARCH 9, 1990
As of noon Friday (PTS), March 9, 1990, the Galileo spacecraft is
57,198,350 miles from Earth, 8,765,750 miles from Venus and is
travelling at a Heliocentric velocity of 89,420 miles per hour. Round
trip light time is 10 minutes, 8 seconds. Galileo continues to spin at
3.15 rpm in cruise mode-dual spin with a spacecraft attitude sun point
angle of 2.3 degrees.
The spacecraft successfully completed three planned SITURNS to
lead the sun on March 4, 6, and 8; all spacecraft performance
indications were as expected.
Telecommunication system elements characterization tests
involving the Command Detector Unit (CDU) and the Radio Frequency
Subsystem were successfully performed on March 4 and 5.
Commands were sent on March 6 to configure the Command and Data
Subsystem (CDS) via the spun Critical Controller (CRC) to route the 10
bps data stream from the Bulk Memory (BUM) to the high rate channel in
both Telemetry Modulation Units (TMU). Beginning March 6 and lasting
through March 25, the telemetry rate will be limited to 10 bits/second
in order to maintain the required link Bit Error Rate (BER).
The AC/DC bus imbalance continued to be relatively stable for
about 6 weeks. The DC measurement has varied between about 21.3 and
21.6 volts; the AC measurement has varied between 48.36 and 48.75
volts. All other power-related measurements (bus voltages, bus
currents and shunt current) and other subsystem measurements have all
been as expected.
The RTG temperature measurement began to exhibit some erratic
behavior on March 8. Due to the very low sample rate of this
measurement at 10 bps (2 hours, 1 minute, 20 seconds), it will require
several samples to determine if this behavior is real and indicative
of another RTG temperature transducer anomaly. The total loss of
these measurements does not pose a threat to the RTG or the spacecraft
since power parameters (V, I) are measured separately by the power
subsystem electronics.
Deep Space Network (DSN) is generating a strawman plan for the
elevation bearing maintenance at all three 70-meter stations for
Project review. This action is deemed necessary because of DSN
concerns following the elevation bearing failure in the antenna in
Spain. The Galileo Flight Control and Support Office (FCSO) is working
with the DSN to minimize the impact to Project support that would result
because of the station downtime required to implement the plan.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.116 | GALILEO Update - March 14 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Thu Mar 15 1990 10:33 | 42 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/14/90
Date: 14 Mar 90 20:14:25 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
March 14, 1990
The distance from spacecraft to Earth today is 62 million miles,
which means that it takes a radio signal more than 11 minutes to go up
to the spacecraft and back. The heliocentric velocity is 88,211 mph,
and declining as the spacecraft pulls away from the Sun. Galileo has
gone more than 256 million miles since launch and has about 391
million to go before the first Earth gravity assist in December.
Spacecraft health continues to be excellent, with most measured
temperatures, pressures, and electrical parameters as expected, except
for the voltage imbalance in the AC and DC power bus, which has been
relatively stable for the past six weeks. The system power margin is
at 58 watts. A total of 1818 real-time commands have been transmitted
to Galileo. Of these, 959 have been pre-planned in the sequence
design and 859 were not. In the past week, a total of 10 real-time
commands were transmitted; 4 were pre-planned and 6 were not. Galileo
is routinely doing Sun-point maneuvers about every two days; the
telemetry rate is now 10 bits per second.
Major activities this week included memory readouts of Star
Intensity Data Buffer, Reset Command Loss Timer, switching the
telemetry rate to 10 bps.
In addition to the three photos sent back from Galileo's flyby of
Venus last month, some infrared light measurements designed to study
Venus' lower atmosphere has been sent back as well as ultraviolet
measurements and data from sensors designed to detect dust and
magnetic fields in space around Venus.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.117 | GALILEO Update - March 16 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Fri Mar 16 1990 20:34 | 68 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/16/90
Date: 16 Mar 90 22:00:01 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
March 16, 1990
As of noon Friday (PST), March 16, 1990, the Galileo spacecraft
is 63,810,650 miles from Earth, 10,496,450 miles from Venus and was
travelling at a heliocentric velocity of 87,640 miles per hour. Round
trip light time is 11 minutes, 18 seconds. Galileo is in cruise
mode-dual spin with a spin rate of 3.15 rpm. The spacecraft attitude
sun point angle is at 0.4 degrees.
Several SITURNS to lead the sun were successfully accomplished on
March 10, 12, 14 and 16. Spacecraft performance for all events was as
expected and without incident.
A switch from LGA-2 (Low Gain Antenna) to LGA-1 was successfully
completed on March 12. The antenna switch was necessary to assure
adequate command and telemetry link performance to accommodate for the
changing sun, earth, and spacecraft relative geometries. After the
switch to LGA-1, the telecommunications performance was near predicted
levels.
The ninth RPM thruster "flushing" activity was completed on March
15, as planned. The activity "flushed" the Z, L and S thruster only.
The P-thrusters were not flushed since they are used to perform the
SITURNS. Unlike earlier "flushing" activities performed at 1200 bps,
the temperature profiles for the thrusters were not available due to
the low telemetry rate of 10 bps. Successful "flushing" was inferred
from other spacecraft measurements/events, including attitude control
performance and thruster counts.
The AC/DC bus imbalance continued to be relatively stable for
about 7 weeks. The DC measurement has varied between about 21.3 and
21.6 volts; the AC measurement has varied between 48.36 and 48.75
volts. All other power-related measurements (bus voltages, bus
currents and shunt current) and other subsystem measurements have all
been as expected.
The Earth Venus Earth (EVE) Integrated Cruise Activity Plan
(ICAP) was reviewed and approved by the project on March 7. The EVE
ICAP is the highest level product integrating engineering and science
activities and covers the period from VE-3 (April 23, 1990) to VE-15
(April 29, 1991).
The VE-2 Preliminary Sequence was reviewed and approved by the
project on March 15. The VE-2 sequence controls spacecraft activities
from March 26 to April 23.
The Galileo project participated in an acceptance test of the new
Deep Space Network (DSN) Telemetry Processor Assembly (TPA) software
during a Goldstone track of the Galileo spacecraft. The new TPA
software will provide a new standard for telemetry time tagging that
will eliminate differences between different TPA configurations and
projects. The new software is expected to begin operations support on
March 29th after the completion of Multimission Verification Tests
(MVTs) scheduled next week.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.118 | GALILEO Update - March 21 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Thu Mar 22 1990 11:24 | 28 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/21/90
Date: 21 Mar 90 21:21:47 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
March 21, 1990
Today the Galileo spacecraft is more than 68 million miles from
Earth, with a round-trip light time of 12 minutes, 14 seconds. It is
almost 69.5 million miles from the Sun, going 86,026 miles per hour in
solar orbit. The spacecraft has now logged almost 271 million miles
in space since launch; it has 376 million to go to its next gravity
assist, at Earth in December, and more than 2 billion miles to go to
its destination, Jupiter in late 1995.
The health of the spacecraft continues to be excellent and its
cruise-mode activity level is relatively quiet. Galileo is spinning
at 3.15 rmp and all general thermal control temperatures are within
acceptable ranges. Tomorrow, the Venus-Earth (VE-2) sequence will be
loaded to the spacecraft and will go active on March 26.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.119 | GALILEO Update - March 23 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Mon Mar 26 1990 13:43 | 84 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/23/90
Date: 24 Mar 90 00:09:16 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
MARCH 23, 1990
As of noon Friday (PST), March 23, 1990, the Galileo spacecraft
is 70,023,320 miles from Earth, 11,852,790 miles from Venus and is
traveling at a heliocentric velocity of 85,320 miles per hour. Round
trip light time is 12 minutes, 26 seconds. The spacecraft's spin
configuration continues at 3.15 rpm with a spacecraft attitude sun
point angle of 0.5 degrees.
Three SITURNS to lead the sun were successfully performed on
March 19, 21, and 23. Spacecraft performance for these activities was
as expected and without incident. A NO-OP command was sent on March
19 to reset the Command Loss Timer to 288 hours consistent with the
plan for this mission phase.
The Venus-Earth (VE-2) sequence memory load was sent on March 22;
the load was successfully transmitted and received by the spacecraft
without incident. The VE-2 sequence controls spacecraft activities
from March 26 to April 23. This sequence includes 12 SITURNS, 1
Retro-Propulsion Module (RPM) flushing activity, several cruise
science Memory Readouts (MROs) for the Magnetometer (MAG), Extreme
Ultraviolet Subsystem (EUV), Dust Detector Subsystem (DDS) and
Energetic Particles Dectector (EPD), and a telemetry data rate switch
back to 40 bps from 10 bps. During early April, from April 9 thru
April 12, time windows have been established for the planned
Trajectory Course Manuever (TCM-4A).
The -x RTG (T4) temperature measurement which began acting
erratically on March 8 went to full saturation on March 21 indicating
an open circuit somewhere between the transducer and the Command and
Data Subsystem (CDS); other CDS measurements routed to this CDS tree
switch are all reading as expected. The loss of these measurements
does not pose a threat to the RTG or the spacecraft since power
performance parameters (V, I) are measured separately by the power
subsystem electronics.
The AC/DC bus voltage imbalance measurements have varied only
slightly. The DC measurement has fluctuated between 21.31 and 21.62
volts; the AC measurement has fluctuated between 48.56 and 48.75
volts. All other power-related measurements (bus voltages, bus
currents and shunt current) and other subsystem measurements have all
been as expected.
Deep Space Network (DSN) support for Galileo continues at 10 bps
without problems, although the B-string telemetry at the stations
experience difficulty in maintaining lock due to the currently
unfavorable ratio of bit rate to subcarrier frequency transmitted by
the spacecraft. The problem is recognized and is considered
acceptable at present. Characterization of the problem by DSN
Operations is in progress.
The impact of the DSN plan for elevation bearing maintenance on
Galileo, particularly the Trajectory Correction Maneuver for Earth
Encounter #1 (TCM-4) is being evaluated by the DSN and Galileo. It
appears that some impact may be inevitable, but the outcome of the
first Goldstone inspection is awaited before any final maintenance
decisions can be made.
A Mission Readiness Test (MRT) with the 34 meter antenna in
Australia was completed successfully, and the Galileo project
participated in a Multi-Mission Verification Test to establish
compatibility of the new DSN Telemetry Processor Assembly (TPA). The
new TPA software is scheduled to begin operational support on April 29.
The Galileo project released about 4.5 hours of its scheduled
tracking coverage on March 22 allowing the International Cometary
Explorer spacecraft (ICE) to collect valuable solar flare data from
the recent event on March 21. The tracking coverage was released only
after successful uplink transmission and total verification of the
VE-2 load on the Galileo spacecraft was completed.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.120 | ICE---a blast from the past | DECWIN::FISHER | Prune Juice: A Warrior's Drink! | Tue Mar 27 1990 21:50 | 3 |
| Nice to know that ICE is still alive and kicking (especially given that it's
useful life had already basically ended several years ago before they sent it
skipping off to beat the Halley crowd!)
|
| 560.121 | GALILEO Update - March 28 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Thu Mar 29 1990 11:45 | 34 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/28/90
Date: 28 Mar 90 21:52:39 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
March 28, 1990
Today the Galileo spacecraft is 74 million miles from Earth, 72
million miles from the Sun. Its speed along its orbit is 83,436 mph,
and the spacecraft has now rolled up 285 million miles since launch.
The second post-Venus sequence is now controlling spacecraft
activities, and will continue to do so through April 23. The sequence
was sent to the spacecraft last Thursday and became active this
Monday. This sequence includes, in addition to routine tasks like
sun-pointing and cruise- science data transmission, scheduled time for
the first of several trajectory-correction maneuvers planned for the
Venus-Earth cruise. These maneuvers will shape the Galileo flight
path for the planned Earth gravity-assist flyby scheduled for December
8 this year.
The spacecraft health is excellent. The telemetry data rate was
raised this morning from 10 to 40 bits per second to take advantage of
improving Earth-spacecraft geometry. All general thermal control
temperatures and tank pressures are within acceptable ranges. A total
of 1821 real-time commands has been transmitted to Galileo.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.122 | GALILEO Update - March 30 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Mon Apr 02 1990 15:26 | 94 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/30/90
Date: 31 Mar 90 00:13:58 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
March 30, 1990
As of noon Friday (PST) , March 30, 1990, the Galileo spacecraft
is 75,701,420 miles from Earth, 12,872,890 miles from Venus traveling
at a heliocentric velocity of 82,650 miles per hour. The spacecraft
continues at a steady 3.15 rpm in a cruise mode-dual spin. Round trip
light time is 13 minutes, 28 seconds.
Three SITURNS to lead the sun were successfully performed on
March 26, 28, and 30. Spacecraft performance for these activities was
as expected and without incident.
The Venus-Earth (VE-2) sequence load went active as planned on
March 26. This sequence controls spacecraft activities to April 23 and
contains 12 SITURNS, 1 Retropropulsion Module (RPM) flushing event,
several cruise science memory readouts (MROs) for the Magnetometer
(MAG), Extreme Ultraviolet instrument (EUV), and Dust Detector
Subsytem (DDS). During early April, from April 9 through April 12,
time windows have been established for the planned TCM-4A (Trajectory
Course Maneuver).
Commands were sent on March 28 to reconfigure the Command and
Data Subsytem (CDS) and Telemetry Modulation Unit (TMU) for 40 bps
coded telemetry data transmission. The data rate switch from 10 bps
to 40 bps was accomplished without incident and involved commanding
the CDS spun critical controllers to route the generated 40 bps data
stream to the TMUs. TMU commands were sent to reset the telemetry
modulation index value to a level compatible with the 40 bps data
rate. Subsequent to the data rate switch, telemetry link performance
was as expected and near predicted levels.
A massive power failure for about 5 hours occurred at the Signal
Processing Center (SPC-40) in Canberra, Australia, on March 28. The
power loss resulted in the loss of planned cruise science MRO data
reception from MAG, EUV and DDS instruments. Later that same day, a
planned SITURN was performed from the VE-2 stored sequence without
flight team monitoring since the 70 meter antenna (DSS-43) was still
down. Upon resumption of DSS-43 tracking coverage, later that day,
telemetry data indicated that the spacecraft executed the SITURN
properly and that spacecraft performance was as expected and without
incident. Science Team members pointed out that nearly all DDS and
MAG science data collected for the last three weeks was still
retrievable if a real time MRO could be performed on March 29. To
assess the risk of doing a MRO, a careful review of the VE-2 scheduled
spacecraft activities was performed; the risk was found to be
acceptable and the MROs were successfully completed.
When the power failure occurred, the station immediately switched
to generator power but was unable to properly configure any links due
to damage to the Network Configuration Facility and other interface
related problems. It was reported that the power outage was due to a
failure in a 22 kv commercial power distribution transformer. During
this power failure voice communication with the station was available.
The Energetic Particles Detector (EPD) instrument was powered
again on March 29, the first time since the Venus flyby, in
preparation for planned motor maintenance activities. Prior to
instrument turn on, however, Delay Action Commands (DACs) were
transmitted on March 28 to reset the EPD input current threshold limit
to a level consistent with expected instrument operation in order to
preclude science safing system fault protection execution.
The AC/DC bus voltage imbalance measurements have fluctuated
slightly. The DC measurement has ranged between 20.9 and 21.62 volts;
the AC measurement has ranged between 47.8 and 48.7 volts. All other
power-related measurements (bus voltages, bus currents and shunt
currents) and other subsystem measurements have all been as expected.
Impact to both TCM-4A and TCM-4B has been eliminated in the
current version of the Deep Space Network (DSN) schedule for elevation
bearing rework throughout the DSN network. Although this schedule is
contingent on satisfactory bearing conditions at DSS-43 and DSS-63 (70
meter antennas at Australia and Spain, respectively) following their
inspections, it will allow work to proceed on the basis of what is
known at present and relieves the immediate concern for Galileo.
New software for the DSN Telemetry Processor Assembly (TPA) that
provides consistent telemetry time tagging between different support
configurations went into "soak" on March 29 and is now being used
for Galileo support.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.123 | GALILEO Update - April 4 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Thu Apr 05 1990 12:10 | 48 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 04/04/90
Date: 4 Apr 90 20:21:57 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
April 4, 1990
Today the Galileo spacecraft is almost 128 million miles from
Earth, and about 75 million miles from the Sun. Its heliocentric speed
is just under 55,000 mph, and it has traveled almost 299 million miles
in space since its launch last October.
The spacecraft's health is excellent, and it is transmitting
telemetry data at 40 bits per second. A week ago, during a Galileo
tracking pass, the Canberra tracking station of the Deep Space Network
experienced a massive power failure and was "off the air" for about 5
hours. A planned memory readout of stored science data from the
spacecraft magnetometer, extreme ultraviolet sensor, and dust detector
was lost but recovered in a commanded replay the next day. The
spacecraft successfully executed a programmed sun- pointing turn
without flight team monitoring during the 5- hour period. When power
was restored and the system came back on line, the Canberra DSN crew
re-acquired the spacecraft signal, including telemetry indicating the
successful turn.
Next week, starting Monday, Galileo will do a four-day
trajectory-correction maneuver designed to take the first step in
shaping the trajectory for the first Earth gravity-assist flyby due
December 8 this year. The spacecraft will thrust periodically as
planned, with tiny ten-newton rocket engines pulsing each time they
rotate past the right direction, for a period of more than 6 1/2 hours
each of the four days. This will slow the spacecraft in its course by
about 6.2 meters per second or 14 mph each day for a total velocity
change of about 25 meters per second or 55 mph. This in turn will
bring the Earth distance at closest approach from 2.4 million
kilometers (1.5 million miles) in the present Galileo orbit down to
about one fifth that value. Several more maneuvers will gradually
reduce the distance to the 950-kilometer altitude required for the
Earth gravity assist. On April 17, ultraviolet spectrometer
measurements will be made on the star Lyma Alpha.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.124 | RE 560.123 | WRKSYS::KLAES | N = R*fgfpneflfifaL | Thu Apr 05 1990 19:07 | 30 |
| Newsgroups: sci.space
Subject: Re: Galileo Update - 04/04/90
Date: 5 Apr 90 16:43:47 GMT
Reply-To: baalke@mars.UUCP (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
In article <12954@csli.Stanford.EDU> jkl@csli.stanford.edu (John
Kallen) writes:
>In article <3282@jato.Jpl.Nasa.Gov> baalke@mars.jpl.nasa.gov (Ron
>Baalke) writes:
>> GALILEO MISSION STATUS
>> April 4, 1990
>...
>>.... On April 17, ultraviolet spectrometer measurements
>>will be made on the star Lyman Alpha.
>
>Eh? Isn't Lyman Alpha a wavelength? Never heard of the constellation
>"Lyman" :-)
You are right. It should have read that ultraviolet spectrometer
measurements will be made on the scattered sunlight on the Lyman-alpha
spectral line to study the distribution of interplanetary gas outside
of Neptune's orbit. Sorry for the confusion.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.125 | GALILEO Update - April 9 | 26523::KLAES | The Universe, or nothing! | Tue Apr 10 1990 15:53 | 107 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 04/09/90
Date: 9 Apr 90 18:09:15 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
April 9, 1990
The Galileo spacecraft is now 80,768,210 miles from Earth,
13,725,620 miles from Venus and traveling at a heliocentric velocity
of 79,790 miles per hour. Round trip light time is 14 minutes, 22
seconds.
Two SITURNS to lead the sun were successfully performed on April
2 and 5. Spacecraft performance for these activities was as expected
and without incident.
Continued periodic characterization tests were successfully
performed for selected telecommunications hardware elements. Command
Detector Unit and radio frequency subsystem element tests were
completed on April 1 and April 2, respectively to characterize
receiver automatic gain control operation, receiver tracking loop
operation and command detector signal-to-noise ratio performance.
The tenth RPM thruster "flushing" activity was successfully
performed on April 6. The activity flushed the Z, L and S thrusters
only. The P thrusters were not flushed since they are used
periodically to perform the SITURNS. These activities were performed
at 40 bps and consequently thruster temperature profiles were not
available due to the low telemetry sample rate. Successful flushing
was inferred from other spacecraft measurements/events, including
attitude control performance and thruster counts.
The Energetic Particles Detector (EPD) instrument was powered on
and commanded from Sector 4 to Sector 0 on April 6 in preparation for
the upcoming Trajectory Course Maneuver (TCM-4A). Contamination
analysis has predicted that Sector 0 is the minimum contamination
position for the EPD. As part of this general EPD activity, an EPD
Memory Read Out (MRO) was also performed. After the MRO, the EPD was
turned off.
Memory readouts were successfully performed as planned on April
2, 5 and 6 to return cruise science data from the Extreme Ultraviolet
(EUV), Magnetometer (MAG) and Dust Detector (DDS) instruments.
Three attitude control related tests were performed on April 2
and 3. Tests consisted of collecting data to update calibration
information for accelerometers, gyros and spin bearing assembly drag
torque.
The DC bus voltage imbalance measurement was observed to have
dropped significantly during the Deep Space Network (DSN) non-tracking
period from end of track on March 30 to the beginning of track in the
afternoon on April 1. The observed drop was about 5 volts and tended
to a more-balanced bus condition. The imbalance reading changed from
21.6 volts to about 16.5 volts. Subsequent to the DC imbalance
measurement drop, it has fluctuated between about 16.5 and 17.5 volts.
No spacecraft activities or power switching events were executed from
the stored sequence during the non-tracking periods; all other
spacecraft telemetry measurements were as expected. The AC bus voltage
imbalance measurement has remained relatively stable varying between
47.5 and 48.2 volts.
Commands were sent on April 6 to modify the maneuver telemetry
map to include additional Retropropulsion Module (RPM) temperature and
Attitude and Articulation Control Subsystem (AACS) telemetry
measurements to provide improve system temperature and delta velocity
performance visibility during the TCM-4A maneuver.
The TCM-4A sequence generation and command products were reviewed
and approved by the Project on April 5. The first of the four
maneuver portions was transmitted on April 8. The other three
portions will be transmitted on subsequent days April 9, 11 and 12.
TCM-4A will be executed from April 9 thru 12 and consist of four
vector mode portions. Each portion (a day's worth of maneuver
activity) will impart a delta velocity magnitude of about 6.18
meters/sec. The maneuver will be performed using only the L-thrusters
with benign duty cycles. A total of 6,372 pulses will be used with a
total estimated fuel consumption of 23.2 kg.
The DSN has completed elevation bearing inspections at the 70
meter antenna at Goldstone, California (DSS-14), and inspection is in
process at the 70 meter antenna at Madrid, Spain (DSS-63). No
problems have been reported that would require additional antenna
downtime. There will be no impact to TCM-4 tracking support if no
additional problems are discovered.
The DSN reports that Mission Readiness Test (MRT) on the 34 meter
antenna at Canberra, Australia (DSS-45), has qualified that station
for support of Galileo when X-band capability becomes available.
The results of the S-band Delta DOR demonstrations on Galileo,
carried out in January and February, show that five of the seven
events yielded very good Very Large Baseline Interferometry (VLBI)
data. The other two events were lost due to a ground software
change-of-day problem and the previously reported spacecraft fault
protection execution (entry into spacecraft safing on January 15,
1990). Lessons learned from this exercise will be incorporated into
Earth Gravity Assist (EGA) Navigation planning.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.126 | GALILEO Update - April 10 | 26523::KLAES | The Universe, or nothing! | Tue Apr 10 1990 18:36 | 37 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 04/10/90
Date: 10 Apr 90 16:45:45 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
April 10, 1990
The Galileo spacecraft is performing a trajectory correction
maneuver this week, to place it on the desired path for its first
Earth gravity-assist flyby early in December 1990. The maneuver, which
will slow the spacecraft by 24.8 meters per second or about 55 mph,
will be carried out in four daily portions, each lasting more than 6
1/2 hours. The spinning spacecraft will deliver tiny pulses from its
lateral thrusters each time one of them is pointed in the right
direction. In the four days, this comes to almost 6400 pulses.
Yesterday, the flight team monitored the first portion of the
maneuver, and sent up the sequence for the second portion. During this
period, Galileo is performing a sun-pointing turn before each day's
maneuver portion. This is the first and largest of several maneuvers
gradually shaping Galileo's flight path for the Earth gravity assist.
The general spacecraft health continues to be excellent. As of
today, Galileo is 83.4 million miles from Earth (round-trip light time
almost 15 minutes). It is traveling at more than 78,000 mph around
the Sun; this week's maneuver will change Galileo's speed by only
about 1/15 of 1 percent. The spacecraft is now about 310 million
miles along the trajectory from launch, with about 2,044 million miles
left to go till arrival at Jupiter.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.127 | GALILEO Update - April 13 | 26523::KLAES | The Universe, or nothing! | Tue Apr 17 1990 17:45 | 123 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 04/13/90
Date: 15 Apr 90 08:36:03 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
April 13, 1990
As of noon Friday, April 13, 1990, the Galileo spacecraft is
85,179,540 miles from Earth, 14,722,470 miles from Venus and traveling
at a heliocentric velocity of 76,850 miles per hour. Round trip light
time is 15 minutes, 10 seconds. The spacecraft is in cruise mode-dual
spin with a spin rate of 3.15 rpm. The spacecraft attitude sun point
angle is 0.7 degrees. Telemetry rate is at 40 bits/second through the
Low Gain Antenna (LGA-1).
The sequence memory load for the first portion of the Trajectory
Course Maneuver (TCM-4A) was transmitted and received without incident
on April 8. A SITURN to lead the sun was successfully performed on
April 8 in preparation for the TCM-4A maneuver execution on April 9.
The SITURN magnitude was selected to provide a near sun-pointed
attitude at the start of the maneuver. Another SITURN to lead the sun
was successfully performed on April 13 after completion of all
manuever activities. The first portion of TCM-4A was successfully
completed on April 9. Preliminary assessments indicate that spacecraft
performance, in general, was well within predicted limits. For the
first three burn segments, the total system performance was excellent.
During the last three burn segments, some increases in pointing error
were observed reaching about 11.5 mrad at the end of the final burn
(well within predictions). This pointing error was subsequently
reduced to about 1 mrad via a sequence planned pointing correction.
It was further observed during this same period that the DC bus
imbalance measurement increased about 1.5 volts (12 DN) to near 19
volts. When firing was completed, the DC bus imbalance measurement
returned close to its initial pre-burn value; no significant change
was noticed on the AC imbalance measurement.
The RPM L-thruster temperature profiles observed during the first
burn segment were lower than predicted and reached a peak of about 158
degree C and 135 degree C for the L1B and L2B, respectively (predicted
level up to 170 degree C). Very early into the second burn segment,
the L2B temperature measurement went to a saturated reading of 255 DN.
The measurement appeared instantaneously to go from the expected 115
DN to 255 DN. This profile characteristic is similar to that seen
during TCM-1 when the Z1A temperature instantaneously went to 255 DN
indicating a likely transducer failure. It is important to remember
that the thruster temperature transducers were added late in the
program to provide additional thruster thermal visibility and were
installed using an unqualified attachment method and their
installation was accepted by the project on a "best-effort" basis.
The sequence memory load for the second, third and fourth portion
of TCM-4A were transmitted and received without incident on April 9,
11, and 12, respectively.
The second maneuver portion of the TCM-4A was successfully
completed on April 10. Prior to the start of burns in this portion, a
SITURN was performed as planned to bring the spacecraft to a near
sun-pointed attitude. Spacecraft performance was again within
predicted levels, however, some performance differences were observed
from the first maneuver portion on April 9. Significant differences
included a larger cumulative pointing error (almost 18 mrad vs 11 mrad
after the last burn segment) but still within the predicted range. In
addition RPM tank pressures were about 0.2 bar lower than predicted.
The pointing error was subsequently corrected to near one-half mrad
with a planned sequence pointing correction. The DC imbalance
measurement during the second portion again exhibited a profile
similar to that observed during the first portion and again very
little change was reported in the AC imbalance reading.
The third portion of TCM-4A was successfully performed on April
11. Similar to the second portion, a SITURN was performed prior to the
burn. Pointing errors continued to exhibit some unexplained growth
during this portion. The cumulative error after the first three burn
segments was about 18.2 mrad. A planned correction was performed
reducing the error to about 1 mrad prior to the start of the next
three burn segments. The next three burn segments caused a cumulative
pointing error of about 22 mrad. The planned pointing correction near
the end of the sequence reduced the error to near 3 mrad. During this
third portion, the RPM tank pressures were observed to be about 0.4
bar lower than predictions but well within acceptable performance
limits. The L1B thruster temperature profile was nearly identical to
that observed in maneuver portions one and two and well within
predicted levels. The DC and AC bus imbalance measurements during this
portion changed only 1 DN significantly different from the 12 DN range
observed in maneuver portions one and two.
The fourth and last portion of TCM-4A was successfully performed
on April 12. Similar to portions two and three a SITURN was performed
prior to the start of the burn activity. The cumulative pointing
error at the end of first three burn segments was 20.2 mrad which was
corrected to approximately 2 mrad via the sequence planned pointing
correction prior to the start of the fourth burn segment. At the end
of the sixth portion the pointing error was 23.2 mrad. This error was
corrected down to about 4 mrad via the planned sequence pointing
correction.
RPM tank pressures gradually dropped from 17.6 to 17.0 bar during
burn segments, a little lower than predicted levels. Once again the
L1B thruster temperature was stable near 158 degree C similar to all
other burn segments. The DC and AC imbalance measurements remained
very stable throughout this maneuver portion varying about one DN.
Preliminary Navigation Analysis has indicated that the TCM-4A
imparted very near the required delta velocity (24.8 m/sec) with a
slight total under burn of about 0.48 m/sec (1.7 sigma). Despite
pointing error changes, RPM tank pressures being a little lower than
predicted in some segments, and the apparent loss of the L2B
temperature transducer, the spacecraft system performance was good
throughout the four-day, 24-segment burn manuever. This is the first
time that the L-thrusters have been used exclusively for a large delta
velocity burn. The number of L-thruster pulses in the TCM-4A was more
than 10 times the number used to date for the entire mission. It is
very possible that the performance changes observed could be attributed
to prediction modeling fidelity of this "new" operating condition.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.128 | GALILEO Update - April 17 | 26523::KLAES | The Universe, or nothing! | Mon Apr 23 1990 19:15 | 31 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 04/17/90
Date: 23 Apr 90 16:34:26 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
April 17, 1990
The Galileo spacecraft is 87,395,218 miles from Earth today
traveling at 75,200 miles per hour relative to the sun. It takes a
radio signal more than 15.5 minutes to make the trip to the spacecraft
and back to Earth. Galileo has traveled more than 323 million miles
since its launch from Earth toward Venus in October last year. It is
on a trajectory back toward Earth for a gravity assist on its long
journey to Jupiter.
The spacecraft continues in excellent condition. The first
four-day portion of a complicated trajectory correction maneuver was
completed April 12, which reduced the spacecraft's velocity by about
55 miles per hour. The second part of the maneuver, expected to
require two days, will be in mid-May. The maneuver recently completed
and the upcoming maneuver in May make up the first of several
maneuvers planned this year to shape the flight path for the flyby of
Earth in December.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.129 | GALILEO Update - April 23 | 26523::KLAES | The Universe, or nothing! | Tue Apr 24 1990 13:34 | 61 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 04/23/90
Date: 23 Apr 90 20:33:32 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
April 23, 1990
The Galileo spacecraft is now 88,910,660 miles from Earth,
16,274,760 miles from Venus and traveling at a heliocentric velocity
of 73,980 miles per hour. Round trip light time is 15 minutes, 52
seconds. The spacecraft is in cruise dual spin mode with a spin rate
of 3.15 rmp. The spacecraft attitude sun point angle is at 2.1 degrees
and the telemetry rate is 40 bps
Two SITURNS to lead the Sun were successfully performed on April
16 and April 19. The spacecraft performance for these activities was
as expected and without incident.
Cruise Science Memory Readouts (MROs) were successfully completed
for the Magnetometer (MAG), Dust Detector Subsystem (DDS), and Extreme
Ultraviolet (EUV) instruments on April 16, 17, and 20.
The Venus-Earth (VE-3) sequence memory load was successfully
transmitted and received without incident on April 20. The VE-3
sequence controls spacecraft activities from April 23 to June 11.
Major activities include nine SITURNS, three RPM flushing events,
fourteen cruise science MROs and four time windows for the Trajectory
Course Maneuver (TCM-4B) planned between May 11 and May 14.
Real Time transmission of a Delay Action Command (DAC) occurred
on April 17 for spacecraft execution on April 19. The DAC was
required to change the scan platform control mode from Scan Type 4 to
6, i.e., from celestial-based position control to encoder-based
position control for the Scan Actuator Subassembly (SAS). This
control mode change precludes unwanted SAS motions resulting from
software commanded peak torques which are likely in Scan Mode 4 when
the spacecraft is also in the inertial mode. Operation in inertial
mode with scan Type 4 was planned as a part of the VE-2 sequence on
April 19.
The DC imbalance measurement fluctuated about 3.3 volts from
about 17 volts to 20 volts. During this same period the AC imbalance
measurement remained fairly stable changing just over 1 volt from 46.5
to 47.7. Some small time correlation between these measurements was
observed; investigation into any spacecraft event correlation is in
process.
Deep Space Network (DSN) reports that the Mission Readiness Tests
(MRT) at the 34 meter antenna in Spain (DSS-65) have been completed
qualifying that station for Galileo support when X-band becomes
available in April 1991. This completes the MRTs for the 34-meter High
Efficiency (HEF) antennas at all sites.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 |
|
| 560.130 | GALILEO Update - April 27 | 26523::KLAES | The Universe, or nothing! | Sun Apr 29 1990 20:25 | 76 |
| Date: 27 Apr 90 23:50:08 GMT
From: jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke)
Subject: Galileo Update - 04/27/90
GALILEO
MISSION STATUS REPORT
April 27, 1990
As of noon Friday (PDT), April 27, 1990, the Galileo spacecraft
is 91,960,640 miles from Earth, 18,762,160 miles from Venus and
traveling at a heliocentric velocity of 71,230 miles per hour.
Galileo is spinning at 3.15 rpm in a cruise mode-dual spin. The
spacecraft attitude sun point angle is at 2.2 degrees. All thermal
control temperature are within acceptable range. Round trip light time
is 16 minutes, 24 seconds.
The Venus-Earth (VE-3) sequence, which was successfully loaded
onboard the spacecraft on April 20, went active as planned on April 23.
Two SITURNS to lead the sun were successfully performed on April
23 and April 26. The spacecraft performance for these activities was
as expected and without incident.
Cruise Science Memory Readouts (MROs) were successfully completed
for the Magnetometer (MAG), Dust Detector (DDS), and Extreme
Ultraviolet (EUV) instruments on April 24 and 27.
The eleventh RPM thruster "flushing" activity was successfully
performed on April 27. The activity flushed the Z, L and S thrusters
only. The P thrusters were not flushed since they are used
periodically to perform the SITURNS. These activities were performed
at 40 bps and consequently thruster temperature profiles were not
available due to low telemetry sample rate. Successful flushing was
inferred from other spacecraft measurements/events, including attitude
control performance and thruster counts.
The AC bus imbalance measurement remained nearly constant
exhibiting very little change from about 47.5 to 48 volts. The DC bus
imbalance measurement, however, fluctuated about 1.6 volts from 21.6
volts to about 20 volts with some fluctuations occurring during
periods of relatively quiescent spacecraft operation; but some
significant DC imbalance measurement changes (3 to 4 volts) were
observed during some DC load switching events associated with the
planned SITURN on April 23. However, during numerous earlier SITURNS
no or very little (1-2 DN) imbalance measurement change was observed.
During the SITURN activity on April 26, the DC bus imbalance
measurement changed approximately 1 DN (.1 volt).
During the uplink of the VE-3, the second command file was
transmitted about two minutes earlier than requested by the Mission
Control Team. This occurred after a ground uplink command abort and
after the uplink had been restarted; the reason for the ground command
abort is currently under investigation. The VE-3 sequence was
properly loaded. The early transmission problem was later reproduced
during ground tests and is associated with the particular procedure
used to send the command files to the Command Processor Assembly (CPA)
at the tracking station. A revised procedure to prevent the early
transmission problem from reoccurring has been implemented while the
Deep Space Network (DSN) investigates the problem further with the
support of the Galileo Flight Control and Support Office.
Investigation of the sinusoidal signature in the doppler
residuals of the 70 meter antenna in Spain (DSS-63), which appeared
shortly after launch prior to DSS-63 antenna bearing downtime, has
been resumed now that DSS-63 doppler data from the Low Gain Antenna
(LGA-1) is available again. Preliminary indications are that the
previously observed variations are no longer present at DSS-63 and are
not seen in the 70 meter antennas in Goldstone (DSS-14) or Australia
(DSS-43). Assessment of the final data will be made before the matter
is closed.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 | Go Lakers!
|
| 560.131 | GALILEO Update - April 30 | 26523::KLAES | The Universe, or nothing! | Tue May 01 1990 17:53 | 31 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 04/30/90
Date: 30 Apr 90 23:02:55 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
April 30, 1990
The Galileo spacecraft is almost 92 million miles from Earth
today, so that a radio signal takes 16 1/2 minutes to go up to the
spacecraft and return. Its speed in orbit around the Sun is 71,230
mph, and it has traveled almost 341 million miles since launch.
Two weeks of spacecraft tracking have confirmed that the four-day
trajectory correction maneuver completed April 12 went extremely well.
The next maneuver, currently being designed, will start May 11 and
take two days.
The spacecraft health countinues to be generally excellent.
Normal cruise activities this week have included Sun-pointing turns,
propulsion system maintenance, and science observations by the
magnetometer, dust and ultraviolet instruments. These activities are
governed by a new operating sequence, transmitted to the spacecraft
last Friday and covering the period from April 23 through June 10.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 | Go Lakers!
|
| 560.132 | GALILEO Update - May 3 | 26523::KLAES | The Universe, or nothing! | Fri May 04 1990 15:27 | 29 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 05/03/90
Date: 3 May 90 22:40:05 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
May 3, 1990
The Galileo spacecraft is about 94 million miles from Earth, and
89.3 million miles from the Sun. It is travelling around the Sun at a
speed of almost 69,000 mph, and it has gone almost 391 million miles
since launch.
The spacecraft health continues to be excellent. Current
activities include routine Sun-pointing about every other day, and
other housekeeping tasks. Science activities include measurements of
the interplanetary environment by the magnetometer, dust detector, and
ultraviolet instruments, which are stored in a computer memory and
read out to Earth about twice a week.
The Galileo flight team is preparing for the next trajectory
correction maneuver, scheduled for Friday and Saturday, May 11-12.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 | Go Lakers!
|
| 560.133 | GALILEO Update - May 4 | 26523::KLAES | The Universe, or nothing! | Mon May 07 1990 17:12 | 94 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 05/04/90
Date: 4 May 90 22:31:55 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
May 4, 1990
As of noon Friday (PDT), May 4, 1990, the Galileo spacecraft is
94,347,620 miles from Earth, 22,390,620 miles from Venus and traveling
at a heliocentric velocity of 68,620 miles per hour. The spacecraft
is in cruise mode-dual spin and is spinning at 3.15 rpm as measured by
its star scanner. Downlink telemetry rate through the Low Gain
Antenna (LGA-1) is 40 bps and the spacecraft attitude sun point angle
is at 1.4 degrees. Round trip light time is 16 minutes, 50 seconds.
Two SITURNS to lead the sun were successfully performed on April
30 and May 4. The spacecraft performance for these activities was as
expected and without incident.
With the beginning of the Australia 70 meter antenna (DSS-43)
tracking pass on April 30 telemetry data indicated that a despun
Command Data Subsystem (CDS) Critical Controller (CRC) A Power on
Reset (POR) had occurred sometime between the end of track late on
April 28 and the start of track on April 30. Other spacecraft
telemetry data was reviewed and spacecraft performance was as expected
except for the POR indication. Later on April 30 with the POR
telemetry indication still present, the spacecraft successfully
performed a SITURN and other activities without incident.
No similar indications were evident elsewhere in the CDS. In
fact, all other CDS telemetry indicators were as expected. The POR
signal is generated by the CDS power converter and sent to the
corresponding Hardware Command Decoder (HCD), and or spun and despun
Critical Controller Circuitry (CRC). The POR signal is normally
generated when either power converter detects a low voltage condition
for several tens of microseconds. No interruptions in processing or
loss of functionality were observed. Once a despun CRC POR indication
is received the logic circuity in the CDS holds that state (via a
latch device) until it is reset by ground command.
Upon completion of initial anomaly analysis, several real-time
command troubleshooting actions were taken to reset the POR bit and
verify operation of the CRC logic circuitry. The actions successfully
reset the POR bit and verified that the POR related logic circuitry is
functioning properly. The success of these actions provides
confidence that the critical controller circuity and telemetry
circuits which monitor this function are working properly. Subsequent
to the ground actions, a command was sent late on April 30 to reset
the Command Loss Timer again in both halves of the CDS because the CDS
POR troubleshooting actions were executed from one side of the CDS.
The cause of this anomaly is unknown. Subsequent test/analysis are in
process investigating the possibility of circuit sneak paths,
noise/part failure sensitivities and possible interaction with AC/DC
imbalance anomaly.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Magnetometer (MAG), Extreme Ultraviolet (EUV) and Dust
Detector (DDS) instruments on May 1 and May 4.
The Energetic Particles Dectector (EPD) instrument was powered on
and commanded from Sector 4 to Sector 0 on May 1 in preparation for
the upcoming Trajectory Course Maneuver (TCM-4B). Contamination
analysis has predicted that Sector 0 is the minimum contamination
position for the EPD. As part of the general EPD activity, an EPD MRO
was performed. After the MRO, the EPD was turned off.
The AC and DC bus imbalance measurement fluctuated slightly
varying about 0.7 volt on the DC measurement and about 3.5 volts on
the AC measurement. The AC imbalance measurement fluctuated during a
period of no spacecraft load switching or motion activity.
The design of TCM-4B was reviewed and approved by the Project on
May 4. This maneuver will consist of two portions totalling
approximately 11.3 meter/second change in velocity and will occur on
May 11 and 12.
Deep Space Network (DSN) and Project representatives are
continuing to investigate the Command System anomaly which resulted in
transmission of a Command File for the Galileo VE-3 sequence two
minutes earlier than requested by the Mission Control Team. A
procedural work around to the problem has been identified and is now
being used. The DSN is considering a fix to the DSN Command Processor
Assembly (CPA), but no decision has been as to whether it is more
appropriate to fix the problem or continue to use the procedural work
around.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 | Go Lakers!
|
| 560.134 | GALILEO Update - May 9 | 26523::KLAES | The Universe, or nothing! | Wed May 09 1990 18:27 | 32 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 05/09/90
Date: 9 May 90 17:10:15 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
May 9, 1990
Today the Galileo spacecraft is 95.7 million miles from Earth.
It is presently going almost 67,000 mph in solar orbit, slowing a
little each day as it recedes from the Sun. It has travelled almost
361 million miles in orbit since launch, and has more than 286 million
miles to go before the first Earth flyby in December.
The spacecraft's health continues to be excellent, and activity
levels rather quiet. However, tomorrow night the first of two
instruction sets for this week's trajectory correction maneuver will
be sent to Galileo, and Friday and Saturday the two portions of the
maneuver will be carried out. This maneuver will slow the spacecraft
in its orbit by 25 mph, less than half the magnitude of the four-day
April trajectory correction.
The magnetometer, dust detector, and ultraviolet instruments
continue to collect, store, and periodically transmit measurements of
the inner solar system environment.
Ron Baalke | baalke@mars.jpl.nasa.gov
Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov
4800 Oak Grove Dr. |
Pasadena, CA 91109 | Go Lakers!
|
| 560.135 | GALILEO Update - May 11 | 26523::KLAES | The Universe, or nothing! | Tue May 15 1990 13:26 | 88 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 05/11/90
Date: 14 May 90 21:01:25 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
May 11, 1990
As of noon Friday (PDT), May 11, 1990, the Galileo spacecraft is
96,096,560 miles from Earth, 27,172,720 miles from Venus and traveling
at a heliocentric velocity of 66,145 miles per hour. Galileo is in
cruise mode-dual spin configuration and spinning at 3.15 rpm. Round
trip light time is 17 minutes, 10 seconds. Major command activity
this week included the Venus-Earth (VE-3) power margin trimming,
disabling sun gate function, uplink sequence loads for the Trajectory
Course Manuever (TCM-4B). Contingency commands were generated to
cancel TCM-4B and turn off the Solid State Imaging (SSI) flash heater
in the event of anomalous attitude excursions during the maneuver burn.
Two SITURNS to lead the sun were successfully completed on May 7
and May 11. The spacecraft performance for these activities was as
expected and without incident. The SITURN on May 11 pointed the
spacecraft to the TCM-4B maneuver desired attitude and was performed
several hours prior to the start of the TCM-4B execution. The
spacecraft attitude sun point angle is at 1.4 degrees
Cruise Science Memory Readouts (MROs) were successfully performed
for the Magnetometer (MAG), Extreme Ultraviolet (EUV) and Dust
Detector (DDS) instruments on May 7 and May 10.
A set of six delayed action commands (DACs) was sent on May 7 to
reconfigure selected electrical heaters trimming the system power
margin to maintain acceptable Retroproplusion Module (RPM) thermal
control. Four DACs were executed before the start of TCM-4B; the
other two DACs are planned for execution several days after TCM-4B.
Commands were sent on May 10 to disable the attitude control sun
gate fault monitors consistent with planned operation for this mission
phase. The sun gate is a Venus-Earth-Earth Gravity Assist (VEEGA)
mission system capability that was added to limit off sun attitude
excursions thereby protecting the High Gain Antenna from
thermal-induced damage inside 1 AU of the sun. Disabling the sun gate
capability significantly reduces the number of SITURNS, thereby
lessening spacecraft operations, Attitude and Articulation Control
Subsystem (AACS) mode changes, and thermal cycling of hardware.
The TCM-4B Portion 1 sequence load was transmitted and
successfully received by the spacecraft on May 10. The second portion
was sent to the spacecraft on May 11 for planned execution on May 12.
This maneuver uses the L-thrusters and is expected to impact a delta
velocity of about 11.3 m/sec. Preliminary assessments indicate the
spacecraft performance was within predicted limits.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____| |_| |_____| Pasadena, CA 91109 |
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 05/11/90 (Forwarded)
Date: 14 May 90 15:49:47 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
ASSOCIATED PRESS -- MAY 11
"The Galileo spacecraft, looping through the solar system on the
way to its 1995 exploration of Jupiter, fired its thrusters today
in a major maneuver meant to steer it near Earth late this year."
AP says it is the second of three or four maneuvers needed to
bring Galileo within 1,000 miles of Earth to alter the
spacecraft's path so it will eventually be headed for Jupiter.
The wire says without the maneuver, the spacecraft would miss the
Earth by more than one-and-a-half million miles.
AP says Galileo is currently travelling about 66,000 miles per
hour and the maneuver slowed it by about 25 mph. The wire says
Galileo is now about 96 million miles away from Earth with its
flyby to take place on December 8, this year.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____| |_| |_____| Pasadena, CA 91109 |
|
| 560.136 | | 19458::FISHER | Prune Juice: A Warrior's Drink! | Tue May 15 1990 16:57 | 4 |
| This may have been explained before, but...what is a SITURN to lead the sun?
From the discussion, it sounds like a gyro unload, but what is the acronym?
Burns
|
| 560.137 | Re: .136 - SITURN | 4347::GRIFFIN | Dave Griffin | Tue May 15 1990 20:35 | 10 |
| Burns, You weren't the only one asking...
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Message-ID: <3685@jato.Jpl.Nasa.Gov>
Date: 15 May 90 17:32:32 GMT
Organization: Jet Propulsion Laboratory, Pasadena, CA.
A SITURN is a small maneuver to keep the front end of Galileo pointed precisely
at the sun, so that most of its instruments are shaded from the sun's heat.
|
| 560.138 | GALILEO Update - May 16 | 26523::KLAES | The Universe, or nothing! | Thu May 17 1990 14:22 | 34 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 05/16/90
Date: 16 May 90 20:53:31 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
May 16, 1990
The spacecraft is about 97 million miles from Earth, giving a
round-trip communications time of 17 minutes 23 seconds. It is moving
in solar orbit at just over 64,500 mph, and has gone almost 372
million miles since launch.
The trajectory-correction maneuver was carried out Friday and
Saturday without any surprises. Two maneuver portions totalling 2,920
pulses from the lateral thrusters were designed by the Galileo flight
team, transmitted by the Deep Space Network, and executed by the
spacecraft as the flight team monitored the activities. The result
was a velocity change of about 11 meters per second (25 mph), bringing
the trajectory closer to the desired conditions for the Earth gravity
assist in December. Four more small maneuvers are scheduled over the
next several months to further refine the trajectory.
After the maneuver, Galileo returned to its regular cruise
routines, keeping sun-pointed and updating its star maps, testing and
calibrating various sensors, and making scientific measurements of the
interplanetary medium.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____| |_| |_____| Pasadena, CA 91109 |
|
| 560.139 | | 25453::MAIEWSKI | | Fri May 18 1990 17:26 | 9 |
| Notice that for the 1st time they didn't give the distance from Venus. I
guess that planet is history.
Also, the speed of 64,500 mph seems slow for an object inside Earth's orbit
yet gaining altitude from the sun. It was going almost 60,000 when it left
earth and that was slow enough for it to be in an orbit that would take it
"down" toward venus. Anyone know how far it is from the sun at this point?
George
|
| 560.140 | The point is that it's now bigger | 39463::REITH | Jim Reith DTN 291-0072 - PDM1-1/J9 | Fri May 18 1990 17:40 | 4 |
| That's a vector speed in the sun's (helio) frame of reference.
It still matters which direction it's pointing ;^)
|
| 560.141 | | 25453::MAIEWSKI | | Fri May 18 1990 18:49 | 8 |
| I understand. I assume that it's in an eliptical orbit with the low point
being near Venus' orbit and the high point being near earth's orbit. Still,
the speed in the direction of it's orbit should slow as the space craft reaches
the high point which it has. It just seems that it's slowed quite a bit
considering that it left Venus a few months ago and has 7 more months until it
get's back to earth.
George
|
| 560.142 | See if you can get one of the gravity assist document that was circulating | 39463::REITH | Jim Reith DTN 291-0072 - PDM1-1/J9 | Fri May 18 1990 19:01 | 7 |
| But Venus is having less of an effect as it gets farther away. I think the
major factor right now is climbing out of the sun's gravity well.
I read the gravity assist document that is going around (Copies were sent
out from one of these notes) and then passed it on to friends. It really is
facinating that you can get "apparently" free velocity. (really just a free
change of the direction vector)
|
| 560.143 | | 25453::MAIEWSKI | | Fri May 18 1990 20:21 | 8 |
| Yeh, I know. It just seemed too slow. Guess it's not.
Anyway, the gravity assist is not really free. I read once that Jupiter will
be one foot behind where it should be 1 trillion years from now because of the
Voyager fly by. I don't remember if that accounted for both fly by's or not
but I'll bet that a trillion years from now no one will remember.
George
|
| 560.144 | | 39463::REITH | Jim Reith DTN 291-0072 - PDM1-1/J9 | Fri May 18 1990 20:59 | 3 |
| Either that or the momentum police will vaporize the planet that sent it out ;^)
Mess up all their nice computer simulation models...
|
| 560.145 | | 25453::MAIEWSKI | | Fri May 18 1990 21:43 | 4 |
| I guess if you are into trillionths of feet per year, Galileo will
shake Jupiter's teeth out. :*0}
George
|
| 560.146 | Not to worry... | 30686::STRANGE | Steve Strange | Fri May 18 1990 22:06 | 6 |
| re: a few back
I think we can safely say that Jupiter will not exist in a trillion
years, so that's correct, no one will notice the 1-foot difference.
Steve
|
| 560.147 | GALILEO Update - May 18 | 26523::KLAES | The Universe, or nothing! | Mon May 21 1990 16:48 | 111 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 05/18/90
Date: 18 May 90 21:37:01 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
May 18, 1990
As of noon Friday (PDT) , May 18, 1990, the Galileo spacecraft is
97,221,520 miles from Earth, 33,004,890 miles from Venus traveling at
a heliocentric velocity of 63,880 miles per hour. The spacecraft
continues in cruise mode-dual spin with a spin rate of 3.15 rmp.
Round trip light time is 17 minutes, 22 seconds.
The spacecraft successfully performed both portions of the
Trajectory Course Manuever (TCM-4B) on May 11 and May 12. Preliminary
assessments indicate that the spacecraft system performance was very
good throughout the two day, 10 segment maneuver. Operation was, in
general, near predicted levels for all spacecraft subsystems.
Articulation and Attitude Control Subsystem (AACS) and Retropropulsion
(RPM) performance was without incident and the largest pointing error
observed was about 12 mrad, after the fourth segment on May 12. This
error was significantly smaller than the nearly 23 mrad observed
during TCM-4A in April 90. After a sequence planned correction, the
pointing error was reduced to less than 1 mrad. As a consequence of
the pointing errors seen in TCM-4A, changes were made to the TCM-4B
maneuver design to reduce pointing error excursions and include
pointing corrections after the second, fourth and fifth burn segments
to correct for accumulated error.
The RPM thruster and cluster temperatures were near predicted
values. The L1B thruster temperature reached a peak temperature of
about 170 degree C, higher than that observed in TCM-4A. The higher
temperature was expected and due to thruster increased on-time planned
during TCM-4B. The cluster temperature reached about 49 degree C
compared with a predicted upper limit of about 70 degree C. RPM tank
pressures and temperatures observed were near predicted levels.
Preliminary analysis indicates the regulators opened near predicted
levels at tank pressures of about 17.1 bars.
The AC and DC bus imbalance measurements fluctuated only slightly
(1 to 4 DN) during the first maneuver portion on May 11 but the DC
imbalance measurement exhibited a significant excursion (25 DN) during
the second maneuver portion on May 12; the AC imbalance measurement
changed only 1 DN. Subsequent to the burn the DC measurement returned
close to its initial pre-burn value. The AC/DC imbalance measurements
remained fairly stable, except as noted during TCM-4B on May 12.
Subsequent to the TCM, the DC measurement fluctuated about 1 volt (10
DN) while the AC measurement fluctuated about 0.8 volt (4 DN). All
other power-related measurements (bus voltage, bus currents and shunt
currents) and other subsystem measurements all were as expected.
Preliminary radio tracking navigation data indicates that the
TCM-4B maneuver imparted near the required delta velocity (11.3 m/sec)
with some small underburn. Investigation is in process to understand
the reasons for the observed underburn. Further collection and
analysis of radio navigation data is currently in process.
Commands were sent on May 12 to reconfigure the Extreme
Ultraviolet (EUV) instrument in an attempt to capture unique
scientific observations including atomic oxygen in the coma of the
Comet Austin. Subsequent to the instrument reconfiguration, EUV data
indicated that the anticipated comet data was not collected even
though the commands were properly transmitted and received.
Consequently, additional commands were sent on May 15 to perform EUV
memory readout (MRO) activities to aid in investigative analysis.
Preliminary analysis indicates the EUV responded properly; further
analysis is in process. It is pointed out that earlier EUV comet data
via MRO was successfully returned and definite confirmation of atomic
oxygen was made.
A SITURN to lead the sun was successfully performed on May 15.
This SITURN, about 9 degrees, was the largest turn performed to date;
spacecraft performance for this activity was as expected and without
incident. This large turn resulted in the spacecraft leading the sun
by about 6 degrees. Larger sun-lead angles are possible now since the
spacecraft is beyond 1 AU from the sun and the sun gate fault monitors
are disabled.
Cruise Science Memory Readouts (MROs) were successfully performed
for the EUV, Magnetometer (MAG) and Dust Detector (DDS) instruments on
May 15 and May 18.
The Energetic Particles Detector (EPD) instrument was powered on
and commanded from Sector O back to Sector 4 on May 15, subsequent to
the TCM-4B maneuver. As part of the general EPD activity, an EPD MRO
was performed. After the MRO, the EPD was turned off.
An attitude control spin detector sensor calibration was
successfully performed on May 16. The spin detector signal is used by
the attitude control system as the source of spin rate data when the
spacecraft is near sun point with gyros unpowered and when star
scanner spin rate data is unusable. Spacecraft performance for this
calibration activity was as expected and without incident.
The twelfth RPM thruster "flushing" activity was successfully
performed on May 18. The activity flushed the Z, L, and S thrusters
only. The P thrusters were not flushed since they are used
periodically to perform SITURNS. These activities were performed to
40 bps and consequently thruster temperature profiles were not
available due to low telemetry sample rate. Successful flushing was
inferred from other spacecraft measurements/events including attitude
control performance and thruster counts.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____| |_| |_____| Pasadena, CA 91109 |
|
| 560.148 | GALILEO Update - May 25 | 26523::KLAES | The Universe, or nothing! | Tue May 29 1990 14:00 | 78 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 05/25/90
Date: 25 May 90 23:54:10 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
May 25, 1990
As of noon Friday (PDT), May 25, 1990, the Galileo spacecraft is
97,747,810 miles from Earth, 39,742,020 miles from Venus and traveling
at a heliocentric velocity of 61,791 miles per hour. Galileo is
spinning at 3.15 rpm in cruise mode-dual spin configuration. The
downlink telemetry rate is at 40 bits/second using the Low Gain
Antenna (LGA-1). Round trip light time is 17 minutes, 30 seconds.
This was a relatively slow week for spacecraft activities.
Activities were limited to one SITURN, Cruise Science memory readouts
and some radio frequency telecommunication tests.
A SITURN to lead the sun was successfully performed on May 21.
The spacecraft performance during this activity was as expected and
without incident. The spacecraft attitude sun point angle is at 0.3
degrees.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Magnetometer (MAG) and Dust
Detector (DDS) instruments on May 21 and May 25.
Commands were sent to the EUV on May 25 to reconfigure the
instrument to gather cruise data following the EUV response to the
commands sent on May 12. The instrument response was due to the
unexpected operation of the EUV polling algorithm.
The operating conditions of the polling algorithm were not well
documented. Simply stated when the microprocessor is not busy it
calls the polling algorithm. When called the polling algorithm
calculates a number by multiplying the number of pixels by the number
of sectors. If the result is greater than 768 then the instrument is
"safed". On May 12 the EUV Fixed Pattern Noise Table (FPNT) was
changed by command; the number of pixels was increased from 21 to 31
to allow collection of Comet Austin O+ data; the number of sectors was
unchanged (35). Prior to commanding changes to FPNT the change was
tested on the EUV simulator. This simulator has a preprogrammed high
count rate. With the high count rate, the EUV microprocessor was busy
and thus the polling algorithm was never activated. The test results
led the EUV Team to the conclusion that the change would work as
planned. Following transmission of the FPNT changes, the EUV
microprocessor, which was operating with a low count rate and thus was
not busy, called the polling algorithm. The product calculated by the
polling algorithm was greater than 768 (31 x 35 = 1085) and the
instrument entered its safe mode. The commands sent on May 25
reconfigured the FPNT to its previous state allowing the collection of
normal cruise data. In the state the polling algorithm if called will
calculate a product which is less than 768.
A radio frequency subsystem (RF) test was successfully performed
on May 25. This periodic RF test collects valuable information
regarding the integrity of S-Band receiver tracking loop capacitors.
The AC/DC bus imbalance measurements exhibited some fluctuations.
The DC measurement dropped about 2.7 volts (25 DN) on May 21 during
periods of no spacecraft activity. The AC measurement meanwhile
remained relatively stable fluctuating about 0.3 volts (3 DN). All
other power-system related and subsystem telemetry measurements were
as expected.
The project reviewed and approved the preliminary sequence and
command generation products for the Venus-Earth (VE-5) sequence on May
25. The VE-5 sequence controls spacecraft activities from June 11 to
October 22.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____/ |_| |_____| Pasadena, CA 91109 |
|
| 560.149 | GALILEO Update - May 30 | 26523::KLAES | The Universe, or nothing! | Thu May 31 1990 12:49 | 37 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 05/30/90
Date: 30 May 90 21:27:47 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
May 30, 1990
The Galileo spacecraft is 97.77 million miles from Earth, and is
approaching Earth at last. The distance passed through a maximum of
97.8 million miles last Monday morning (8:17 a.m. PDT) and has been
getting shorter ever since. Galileo is more than 101 million miles
from the Sun, still receding toward a distance of 119 million miles
in late August. The speed in solar orbit is down to 60,409 mph.
As the spacecraft has moved further from the Sun, the Sun angle
has been changing more slowly, and the intensity of solar heating has
fallen off. The sun-pointing maneuvers, which keep Galileo behind and
protected by its sunshades, have been reduced from every other day to
twice a week, and at present, been further reduced to about once a
week. Otherwise, spacecraft activity levels are rather quiet, except
for the continuing cruise science data collection and the routine
engineering-related tests. Spacecraft performance continues to be
excellent.
On the ground, the Galileo flight team continues the process of
developing and reviewing the flight sequence covering the period from
June 11 to October 22, which will include two small trajectory
correction maneuvers as well as continuing cruise science and routine
engineering operations.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____/ |_| |_____| Pasadena, CA 91109 |
|
| 560.150 | | 25453::MAIEWSKI | | Thu May 31 1990 21:32 | 15 |
| >Galileo is more than 101 million miles
>from the Sun, still receding toward a distance of 119 million miles
>in late August. The speed in solar orbit is down to 60,409 mph.
So it was kind of slow. This means that Galileo is currently further
from the sun than we are.
So the change in orbit as it went by Venus was not only wider, it
gave it extra energy to take it outside Earth's orbit.
Now, will it come inside the Earth's orbit and catch us from behind
or will it remain outside Earths orbit so that we can catch it from
behind?
George
|
| 560.151 | GALILEO Update - June 1 | 26523::KLAES | The Universe, or nothing! | Tue Jun 05 1990 20:03 | 52 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 06/01/90
Date: 1 Jun 90 20:18:15 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
June 1, 1990
As of noon Friday (PDT), June 1, 1990, the Galileo spacecraft is
97,707,550 miles from Earth, 46,123,940 miles from Venus and traveling
at a heliocentric velocity of 60,145 miles per hour. The spacecraft
is is spining at 3.15 rpm and the downlink telemetry rate is at 40
bps. Round trip light time is 17 minutes, 30 seconds.
A SITURN to lead the sun was successfully performed on May 29 to
put the spacecraft attitude sun point angle at 3.5 degrees. The
spacecraft's performance during this activity was as expected and
without incident.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Utraviolet (EUV), Magnetometer (MAG) and Dust Detector
(DDS) instruments on May 29 and June 1. The EUV MRO conclusively
demonstrated the reconfiguration of the Fixed Pattern Noise Table
(FPNT) and the proper operation of the instrument.
A telecommunications system Command Detector Unit (CDU)
Signal-to-Noise Ratio (SNR) test was successfully completed on May 31.
This periodic test provides performance information relative to the
spacecraft's digital Command Detector Unit used to detect uplink
command bits and route them to the Command Data Subsystem (CDS).
In addition to the CDU telecommunication test, a radio receiver
Automatic Gain Control (AGC) test was successfully completed on June 1.
This periodic test provides performance information relative to the
spacecraft radio frequency subsystem's receiver automatic gain control
elements.
The AC/DC bus imbalance measurements remained very stable. The
imbalance measurements fluctuated less than 0.5 volt over the entire
period.
The Deep Space Network (DSN) reports that the load balance task
is now complete at the 70 meter antenna station in Spain (DSS-63) and
that the station should return to service on June 4 as scheduled.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____/ |_| |_____| Pasadena, CA 91109 |
|
| 560.152 | GALILEO Updates - June 6-7 | 26523::KLAES | The Universe, or nothing! | Fri Jun 08 1990 16:05 | 103 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 06/06/90
Date: 6 Jun 90 18:51:50 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
June 6, 1990
The spacecraft is about 97.4 million miles from Earth, a distance
now decreasing at a rate of 100,000 miles per day. It has traveled
almost 403 million miles since launch, and presently has a speed of
58,625 mph in solar orbit.
At last week's national meeting of the American Geophysical Union
in Baltimore, Thomas Garrard of Caltech presented a paper coauthored
with Edward Stone on "Heavy ions in the October 1989 solar flares
observed on the Galileo spacecraft," the first formal scientific
report resulting from the mission.
Meanwhile out beyond Earth's orbit the Galileo spacecraft
continues to conduct planned engineering tests and scientific
observations of the interplanetary environment. Spacecraft
performance continues to be excellent. The new Venus-to-Earth cruise
sequence is to be sent to the spacecraft June 8 and will take effect
June 11.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____/ |_| |_____| Pasadena, CA 91109 |
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 06/07/90
Date: 8 Jun 90 00:27:51 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
June 7, 1990
As of noon Thursday (PDT), June 7, 1990, the Galileo spacecraft
is 97,249,190 miles from Earth, 54,151,860 miles from Venus and
traveling at a heliocentric velocity of 58,385 miles per hour. The
spacecraft is in cruise mode-dual spin configuration with a spin rate
of 3.15 rpm. Round trip light time is 17 minutes, 24 seconds.
A SITURN was successfully performed on June 4 to place the
spacecraft attitude sun point angle at 3.4 degrees. Spacecraft
performance for this activity was as expected and without incident.
Commands were sent on June 4 to update the spin detector bias and
scale factor parameters based on a previous calibration activity.
These parameter updates allow the spin detector data to be used to
"seed" SEQID if the star scanner data becomes unusable.
Cruise Science Memory Readouts (MROs) planned for June 4 were
partially lost due to a false fire alarm alert in the X-band cone at
the tracking station in Australia (DSS-43) which required stowing the
70-meter antenna. The fire alarm alert seemed to be coupled with the
use of the high power S-Band (100 kw) transmitter which was requested
by the project to collect navigation ranging data. In all, more than
one hour of tracking coverage was lost resulting in loss of MRO data
for the Dust Dectector (DDS) and Magnetometer (MAG) instruments. The
problem is under investigation by the Deep Space Network.
The AC/DC bus imbalance measurements remained very stable. The
DC imbalance measurement fluctuated about 1.1 volts over the entire
period; the AC measurement fluctuated about 0.2 volts.
The project reviewed and approved the final sequence and command
generation products for the Venus-Earth (VE-5) sequence on June 5.
This sequence controls spacecraft activities from June 11 to October
22. This is the longest stored sequence generated to date and
contains major events such as five SITURNS, six Retropropulsion Module
(RPM) flushing activities, three telecommunications system tests,
numerous cruise science memory readouts and several engineering
calibration activities. In addition, time windows in VE-5 are provided
for Trajectory Course Manuevers (TCM-5 and TCM-6) planned for mid-July
and early October, respectively. The sequence is scheduled to be
transmitted to the spacecraft on June 8.
The Deep Space Network (DSN) reports that all work associated
with the upgrade of two X-band masers for the German Space Operations
Center (GSOC) Weilhiem tracking station has been completed. The
upgrade funded by FRG will improve the performance of the masers used
by GSOC to support Galileo Cruise Science starting in September 1991.
Initial X-band testing with the spacecraft is planned for May 1991.
Planning for the S-band array test before first Earth flyby is
continuing. The preliminary date for the test with the spacecraft is
November 26th with backup on December 5th. The objective of the test
is to demonstrate performance of S-band arraying which could be used
to reduce the need for 70 meter station coverage during the second
Earth flyby flyby in December 1992.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____/ |_| |_____| Pasadena, CA 91109 |
|
| 560.153 | GALILEO Update - June 14 | 26523::KLAES | The Universe, or nothing! | Mon Jun 18 1990 19:52 | 72 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 06/14/90
Date: 17 Jun 90 19:04:35 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
June 14, 1990
As of noon Thursday (PDT), June 14, 1990, the Galileo spacecraft
is 96,243,340 miles from Earth, 62,678,100 miles from Venus and
traveling at a heliocentric velocity of 56,796 miles per hour.
Galileo's spin rate remains at 3.15 rpm in dual spin configuration.
Round trip light time is 17 minutes, 14 seconds.
The Venus-Earth-5 (VE-5) sequence was successfully transmitted
and received by the spacecraft on June 8. This sequence controls
spacecraft activities from June 11 to October 22. This is the longest
stored sequence generated to date and contains major events such as
five SITURNS, six RPM flushing activities, three telecommunications
system tests, numerous cruise science memory readouts and several
engineering calibration activities. In addition, time windows are
provided for Trajectory Course Maneuvers (TCM-5 and TCM-6) planned for
mid-July and early October, respectively. The VE-5 sequence went
active as planned on June 11.
The thirteenth Retropropulsion Module (RPM) thruster "flushing"
activity was successfully performed on June 8. The activity flushed
the Z, L, and S thrusters only. The P thrusters were not flushed
since they are used periodically to perform SITURNS. These activities
were performed at 40 bps and consequently thruster temperature
profiles were not available due to low telemetry sample rate.
Successful flushing was inferred from other spacecraft
measurements/events including attitude control performance and
thruster counts.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Magnetometer (MAG) and Dust
Detector (DDS) instruments on June 8, 11 and 14.
A SITURN was successfully performed on June 14. This turn, about
13 degrees, was the largest turn performed to date. Spacecraft
performance for this activity was as expected and without incident.
Four electrical heaters were activated on June 11 to maintain
acceptable thermal control for the Plasma Subsystem (PLS), Bay A
electronics, and the Near Infrared Mapping Spectrometer (NIMS).
The Plasma Wave (PWS) magnetic field pre-amplifier thermal
control algorithm was enabled on June 11. This algorithm
automatically controls the state of the electrical heater used to
maintain proper thermal control of the PWS.
The AC/DC bus imbalance measurements have remained very stable.
The AC measurement continues to indicate a near short circuit to
chassis. The DC measurement continues to indicate a reading near 20.4
volts. No significant measurement changes were observed when the
electrical heater loads were powered on.
Results of further analysis of the EUV data at the University of
Colorado now suggests that the earlier detection of O+ emissions from
Comet Austin was due to internal Lyman Alpha scattering in the
instrument. Hence at this time no positive detection of Comet Austin
in O+ can be reported.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____/ |_| |_____| Pasadena, CA 91109 |
|
| 560.154 | GALILEO Update - June 20 | 26523::KLAES | The Universe, or nothing! | Thu Jun 21 1990 17:51 | 36 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 06/20/90
Date: 21 Jun 90 16:28:33 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
June 20, 1990
The Galileo spacecraft is 95 million miles from Earth today;
round-trip light time is 17 minutes. Since launch, Galileo has logged
almost 422 million miles in solar orbit, and is currently traveling at
about 55,570 mph.
Activities on the spacecraft continue to be routine and
performance is excellent. Operations are now directed by a new
software sequence transmitted June 8. This sequence will control the
spacecraft until late October, and includes planned opportunities for
two more trajectory-correction maneuvers.
Preliminary reports of Galileo scientific observations of Venus
from last February's flyby are scheduled for the Committee for Space
Research (COSPAR) conference next week in the Netherlands. The
reports are from the imaging and near-infrared mapping spectrometer
teams and are based on sample data sent back using an experimental
procedure soon after the encounter, when the available data rate was
too low for normal playback. The full Venus science data will be
played back in late November when communications conditions permit a
higher data rate.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____/ |_| |_____| Pasadena, CA 91109 |
|
| 560.155 | GALILEO Update - June 21 | 26523::KLAES | The Universe, or nothing! | Fri Jun 22 1990 15:18 | 58 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 06/21/90
Date: 22 Jun 90 01:21:19 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
June 21, 1990
As of noon Thursday (PDT) , June 21, 1990, the Galileo spacecraft
is 94,751,810 miles from Earth, 71,573,100 miles from Venus and
traveling at a heliocentric velocity of 55,374 miles per hour. The
spacecraft spin rotation is at 3.15 rpm in a dual spin configuration.
The spacecraft attitude sun point angle is at 4.5 degrees. Round trip
light time is 16 minutes, 58 seconds.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Magnetometer (MAG) and Dust
Detector (DDS) instruments on June 18 and 21.
Commands were sent on June 18 to power on the Energetic Particles
Detector (EPD) replacement heater to maintain instrument temperatures
within acceptable limits. Flight data indicated that portions of the
EPD could drop below the flight allowable lower temperature limit of
-25 degree C without additional heater power. Subsequent to the
heater turn-on, temperatures increased to near predicted levels and
are well within acceptable temperature ranges. Also on June 18, four
EPD-related Delay Action Commands (DACs) were transmitted. These
commands will be executed by the spacecraft on June 21 and cycle the
EPD replacement heater off and then on again after the planned EPD
motor stepping activity.
The EPD motor was successfully stepped on June 21 as part of its
motor maintenance activity. The EPD was moved to Sector O and then
back to Sector 4. EPD performance was as expected and without incident.
Commands were sent on June 18 updating the DDS memory with a new
program. This program allows DDS increased memory storage which will
be used to capture low signal amplitude dust events. The program is
scheduled to begin executing next week.
The AC/DC bus imbalance measurements have remained very stable.
The AC measurement continues to indicate a near short circuit to chassis.
The DC measurement continues to indicate a reading near 20.4 volts.
The first series of "scrubs" to the Attitude and Articulation
Control Subsystem (AACS) flight software memory was approved. These
scrubs are required to provide adequate space for the pulse mode high
rate spin up that will be used during Probe release and all 400 Newton
engine burns.
_ _____ _
| | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov
| | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
___| | | ___/ | |___ M/S 301-355 |
|_____/ |_| |_____| Pasadena, CA 91109 |
|
| 560.156 | GALILEO Updates - June 27-28 | 26523::KLAES | The Universe, or nothing! | Mon Jul 02 1990 16:42 | 88 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 06/27/90
Date: 28 Jun 90 19:09:35 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
GALILEO MISSION STATUS
June 27, 1990
The Galileo spacecraft is now 92.8 million miles from Earth, with
the distance declining at about 300,000 miles per day. The round-trip
light time is 16 minutes, 38 seconds. The spacecraft orbital speed is
just over 54,000 mph, declining gradually as it moves away from the Sun.
At JPL, the Galileo navigation and orbiter engineering teams have
begin designing the third trajectory correction maneuver since the
Venus flyby last February. This will continue the process of precisely
shaping the flight path for the December 1990 gravity-assist flyby of
Earth. The finished maneuver parameters will be transmitted to the
spacecraft and executed in mid-July.
At the spacecraft, the activity level is very quiet, with
continued scientific measurements of the interplanetary environment,
periodic memory readouts of the data, and occasional calibrations,
Sun-point maneuvers and other engineering housekeeping routines.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
Date: 28 Jun 90 23:13:38 GMT
From: (Ron Baalke)
Subject: Galileo Update - 06/28/90
GALILEO
MISSION STATUS REPORT
June 28, 1990
As of noon Thursday (PDT), June 28, 1990, the Galileo spacecraft
is 92,806,165 miles from Earth and traveling at a heliocentric
velocity of 54,113 miles per hour. The spacecraft is spinning at 3.15
rpm in cruise dual spin configuration. Round trip light time is 16
minutes, 38 seconds.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Magnetometer (MAG) and the Dust
Detector (DDS) instruments on June 25 and 28. The spacecraft tape
recorder conditioning was performed on June 25 as planned.
The fourteenth Retropropulsion Module (RPM) "flushing" activity
was successfully performed on June 28. The Z, L and S thrusters only
were flushed since the P thrusters are periodically used to perform
SITURNS. Thruster flushing was performed at 40 bps. Detailed thruster
temperature profiles are not available at this data rate. Successful
flushing was inferred from other spacecraft telemetry measurement/events
including Attitude and Articulation Control Subsystem (AACS) performance
and thruster counts.
The third of a three part Acquisition Sensor Calibration was
performed on June 25 as planned. All required data was collected.
The DDS memory change commanded last week went active on June 25, as
commanded. DDS memory readout confirms that the memory changes required
to capture low signal amplitude dust events was correctly loaded.
The AC bus imbalance measurements this week were very stable and
continue to indicate a near short circuit to chassis. The DC bus
imbalance measurement showed more activity this week varying between
164 and 174 DN. The circuit measurement indicates 20.5 volts.
The Venus-Earth-9 (VE-9) Cruise Plan was reviewed and approved by
the project on June 27. This sequence covers the period from October
22 thru December 7 and includes windows for Trajectory Course Manuevers
(TCM-7 and TCM-8). It also includes the Venus science data playback
and the pre-Earth 1 Science Instrument turn-on and calibration.
The Deep Space Network (DSN) reports that the load balancing work
at the 70 meter tracking station (DSS-43) in Australia was completed
and the 70 meter antenna returned to service one week early. DSS-43
provided its initial post balancing Galileo tracking support on June 26.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.157 | GALILEO Update - July 5 | 26523::KLAES | The Universe, or nothing! | Fri Jul 06 1990 15:23 | 41 |
| Date: 5 Jul 90 18:04:24 GMT
From: (Ron Baalke)
Subject: Galileo Update - 07/05/90
GALILEO MISSION STATUS
July 5, 1990
The Galileo spacecraft is 90.4 million miles from Earth, which
means the round-trip communication time is 16 minutes, 12 seconds.
Speed in orbit is 53,000 mph; the speed will reach a minimum of 49,467
mph in August, when Galileo's present orbit takes it farthest from the
Sun; it will then move back, approaching Earth from the nightside this
December.
Preliminary reports on Galileo's Venus observations last
February, just presented at a conference in the Netherlands, show
tantalizing glimpses of cloud structure in the lower atmosphere, quite
different from the cloud-top patterns seen previously. Galileo's
imaging system, which obtained day-side pictures through both violet
and near-infrared filters, showed previously undetected markings at
lower levels; the near-infrared mapping spectrometer, viewing both
night and day sides, found structure and brightness variations at
various IR wavelengths. These analyses are based on a small sample
of data read out by the spacecraft last spring, and they offer great
promise for the full Venus playback in late November, as well as for
the comprehensive study of Jupiter's atmosphere scheduled to begin in
1995.
Meanwhile on the spacecraft, things are generally quiet.
Scheduled calibrations and engineering maintenance tasks continue to
be performed, and the "cruise science" instruments continue to collect
their data. Telemetry readings are as expected and spacecraft
performance is excellent.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.158 | GALILEO Update - July 6 | 26523::KLAES | The Universe, or nothing! | Mon Jul 09 1990 15:47 | 62 |
| Date: 6 Jul 90 17:56:55 GMT
From: (Ron Baalke)
Subject: Galileo Update - 07/06/90
GALILEO
MISSION STATUS REPORT
July 6, 1990
As of noon Friday (PDT), July 6, 1990, the Galileo spacecraft is
90,432,295 miles from Earth and traveling at a heliocentric velocity
of 53,015 miles per hour. The spacecraft continues to spin at 3.15
rpm in a dual spin cruise configuration. Downlink telemetry rate is
at 40 bps and all temperatures are within acceptable ranges. Round
trip light time is 16 minutes, 14 seconds.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Magnetometer (MAG) and Dust
Detector (DDS) instruments on July 2 and 5.
A SITURN was successfully performed on July 5. This turn, about
10 degrees, was completed as planned. During the turn the P1A
thruster temperature transducer rose as expected and then indicated
full saturation (255 DN) toggling twice between the expected value and
full saturation. This pattern is similar to the pattern on both the
Z1A and the L2B thruster temperature transducers and may indicate the
future permanent loss of the P1A thruster temperature transducer.
Other than this anomaly the SITURN was completed as planned.
A radio frequency subsystem, tracking loop capacitor test was
conducted on July 5 as planned. Data collected is being analyzed.
Ultra Stable Oscillator (USO) test was conducted on July 2. This
is the second of fifteen USO tests scheduled for Venus-Earth-5 (VE-5).
The purpose of these tests is to provide continuing trend information
characterizing the performance of the USO.
Attitude and Articulation Control Subsystem (AACS) wobble calibration
test was conducted on July 5. Required data was collected as planned.
The AC bus imbalance measurement was relatively stable during
the past week varying 8 DN. The AC imbalance measurement currently
indicates a near short to chassis (48.9 volts). The DC imbalance
measurement was relatively stable throughout the week varying
approximately 11 DN. On July 5 between 1902 and 1915 UTC, the DC bus
imbalance fluctuated significantly decreasing nearly 40 DN in two
discrete steps prior to increasing 20 DN. The DC bus imbalance
measurements currently indicate 18.5 volts. Any possible relationship
between spacecraft events/activities and the changing DC bus imbalance
is being investigated.
Lyman Alpha data was collected by the Ultraviolet Spectrometer
(UVS) instrument and stored on the spacecraft tape recorder (DMS) for
playback in November. This is part of a continuing UVS cruise data
gathering program.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.159 | GALILEO Update - July 12 | 26523::KLAES | The Universe, or nothing! | Fri Jul 13 1990 14:25 | 34 |
| Date: 12 Jul 90 16:48:00 GMT
From: (Ron Baalke)
Subject: Galileo Update - 07/12/90
GALILEO MISSION STATUS
July 12, 1990
The Galileo spacecraft is 87.7 million miles from Earth
(round-trip communication time 15 minutes 43 seconds) and 114.6
million miles from the Sun. It has travelled 450 million miles in
space since launch last October 18, and its heliocentric speed is
now just over 52,000 mph.
The flight team has developed and reviewed the design of next
week's trajectory correction maneuver. It calls for 228 pulses using
the axial thrusters (toward the Sun) and 160 lateral pulses (at nearly
a right angle to the Sun-line) for a total velocity change of less
than one meter per second (about 2 mph). The command sequence will be
sent to the spacecraft next Monday, and the maneuver operation will
begin about 11 a.m. (PDT) Tuesday, July 17.
Meanwhile, at the spacecraft, things are relatively quiet.
Routine science observations of the interplanetary environment
continue, with data readouts about every 4-5 days; there are also
regular scheduled engineering calibrations and system maintenance
activities. Galileo's performance continues to be excellent.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.160 | GALILEO Update - July 12 | 26523::KLAES | The Universe, or nothing! | Mon Jul 16 1990 16:08 | 75 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/12/90
Date: 13 Jul 90 00:10:51 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
GALILEO
MISSION STATUS REPORT
July 12, 1990
As of noon (PDT) Thursday, July 12, 1990, the Galileo spacecraft
is 87,688,100 miles from Earth and traveling at a heliocentric
velocity of 52,070 miles per hour. The spacecraft is spinning at 3.15
rpm as measured by its star scanner, and is in dual spin cruise
configuration. Round trip light time is 15 minutes, 44 seconds.
A command was sent on July 9 to power-on the scan actuator 4-watt
heater to maintain the gyros within acceptable thermal limits. The
additional power is necessary now that the spacecraft is beyond 1 AU
from the Sun.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Magnetometer (MAG) and Dust
Detector (DDS) instruments on July 9 and 12.
The periodic Command Detector Unit (CDU) signal-to-noise ratio
and the Radio Frequency Subsystem (RFS) receiver automatic gain
control tests were successfully performed on July 11. These
telecommunications tests collect data to characterize the performance
of the S-Band receiver and the command detector elements.
A Ultra Stable Oscillator (USO) test was conducted on July 12.
This test provides continuing trend information characterizing the
performance of this ultra-stable RF downlink frequency source.
The Plasma Wave (PWS) magnetic field electronics heater has
recently exhibited more on/off cycles (about once/day) than
anticipated. This heater interface is automatically controlled by an
on-board CDS thermal monitor algorithm. The thermal limits (-10
degree C to 25 degree C) are presently set with some margin to
maintain the PWS electronics within its flight allowable temperature
range. Since long-term deep thermal cycling may result in solder
joint degradation, options have been developed to reduce or preclude
the depth and number of PWS thermal cycles. A system/science
evaluation of the options is in process. At present the PWS magnetic
field sensor/electronics are not at risk.
A series of three sets of delayed action commands (DACs) was sent
on July 12 to properly set the Energetic Particles Detector (EPD)
heater configuration to allow safing and unsafing of the EPD before
and after the Trajectory Course Manuever 5 (TCM-5) and motor
maintenance activity. Prior to TCM-5, the EPD will be stepped to
Sector 0, the minimum plume contamination position. After TCM-5, EPD
will be repositioned to Sector 4. The third set DACs will be executed
as part of the periodic EPD motor maintenance activity scheduled for
September 1990.
The AC/DC bus imbalance measurements remained relatively stable.
The AC measurement continues to indicate a near short circuit path to
chassis. The DC measurement has stabilized and remained near 18.5 volts
after the fluctuations observed during last week's SITURN activity.
The TCM-5 sequence will be executed by the spacecraft on July 17.
The maneuver will be performed in vector mode and consist of an axial
burn (using Z thrusters) and lateral burn (using the L thrusters).
The total velocity increment expected is about 0.9 m/sec. The TCM-5
maneuver uplink process was accomplished on an accelerated schedule
validating the TCM-8 schedule requirements on July 12.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.161 | GALILEO Updates - July 19-20 | 26523::KLAES | The Universe, or nothing! | Mon Jul 23 1990 22:10 | 129 |
| Date: 20 Jul 90 00:44:49 GMT
From: (Ron Baalke)
Subject: Galileo Update - 07/19/90
GALILEO MISSION STATUS
July 19, 1990
The Galileo spacecraft is 84.6 million miles from Earth, its
orbit very slightly changed by Tuesday's successful trajectory
correction maneuver. The round-trip communication time is now 15
minutes, 10 seconds. Speed relative to the Sun is more than 51,000 mph.
This maneuver, the fifth since launch and third since the Venus
gravity assist, was designed to refine the flight path toward the
desired conditions for the Earth gravity assist. The spacecraft
departed from Venus in February with, as expected, a heading almost
but not quite toward its December 8 Earth rendezvous. A small part of
the velocity change were to be contributed by spacecraft maneuvers in
April and May and this week. The small maneuvers scheduled for
October and November will do the final fine-tuning. The resulting
Earth flyby will occur at 20:35 GMT or 12:35 p.m. PST December 8, more
than 500 miles above the western Atlantic.
This week's maneuver was itself small: 228 axial pulses and 160
lateral pulses changed the spacecraft velocity by 0.92 meters per
second (about 2 mph), compared with 24 and 11 m/sec in the two
previous maneuvers.
Spacecraft health continues to be excellent, and system
performance also excellent. The Deep Space Network provided
round-the-clock tracking and telemetry coverage of Galileo for the few
days around the maneuver; normal cruise coverage at this time is about
one pass per day.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
Date: 20 Jul 90 16:28:57 GMT
From: (Ron Baalke)
Subject: Galileo Update - 07/20/90
GALILEO
MISSION STATUS REPORT
July 20, 1990
As of noon (PDT) Thursday, July 19, 1990, the Galileo spacecraft
is 84,584,600 miles from Earth and traveling at a heliocentric
velocity of 51,270 miles per hour. The spacecraft's spin rate is at
3.15 rpm is in dual spin configuration. Round trip light time is 15
minutes, 12 seconds.
A NO-OP command was sent on July 16 to reset the Command Loss
Timer to 264 hours, the planned value for this mission phase.
The Energetic Particles Detector (EPD) instrument was turned on
and the motor successfully stepped on July 16 from Sector 4 to Sector
O in preparation for the Trajectory Course Manuever-5 (TCM-5) on July
17. Contamination analysis has predicted that Sector O is the minimum
contamination position for the EPD. Subsequent to the TCM-5 maneuver
on July 17, the motor was stepped back to Sector 4. As part of both
EPD stepping activities, EPD Memory Read Outs (MROs) were performed.
After the MROs, the EPD was turned off.
The sequence memory load for the TCM-5 maneuver was successfully
transmitted and received by the Spacecraft on July 16. Successful
execution of the TCM-5 maneuver occurred on July 17. Total spacecraft
performance throughout the maneuver was near predicted levels. All
Retropropulsion Module (RPM) pressures and temperatures were near
expected levels; the Z thruster temperature profiles were similar to
those of previous Z thruster burns. The L2B thruster temperature was
inferred from the cluster temperature sensor readings. No unexpected
cluster temperatures were observed. After the axial burn segment, a
sequence planned pointing error correction was performed to reduce the
error from about 4 mrad to near one-half mrad. No pointing error
correction was needed after the lateral burn segment. Spin rate
corrections were not needed following either the axial or the lateral
burn segments. As previously reported the P1A temperature transducer
appeared to be near failure. During the pointing correction following
the axial segment of TCM-5 on July 17, the P1A temperature transducer
immediately indicated full saturation (255 DN) after the very first
pulse; it is still indicating 255 DN.
Preliminary navigation data indicates a small overburn (about 2%)
for the axial segment and an even smaller underburn (about 0.2%) for
the lateral segment. Orbit determination data collection is in process.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Magnetometer (MAG) and Dust
Detector (DDS) instruments on July 16 and 19.
The fifteenth RPM "flushing" activity was successfully performed
on July 19. All 12 RPM thrusters were flushed during this activity.
Detailed thruster temperature profiles are not available due to
operation at 40 bps. Successful flushing was inferred from other
spacecraft telemetry measurement/events including Attitude and
Articulation Control Subsystem (AACS) performance and thruster counts.
Commands were sent July 18 to perform a MAG instrument special
MRO and a main power off/on cycle. These actions were taken to
collect data to help understand the cause of recent MRO data anomalies
first reported to project on July 13. Careful review of earlier MAG
MRO data revealed some evidence of anomalous data visible in the June
8 MRO. Preliminary analysis of the special MRO revealed several
memory miscompares in the executive portion of the MAG memory. Due to
the memory miscompares the power off/on cycle was inconclusive in
totally verifying the proper operation of the processor and logic
circuitry. Further troubleshooting actions are being considered
including a complete MAG memory reload. The cause of the memory
miscompares is under investigation but may be related to a solar flare
event on June 7. To date no other subsystem has reported any anomalous
memory-related behavior. Interaction with the principal investigator
has confirmed that the instrument is not at risk if the miscompares
are due to transient events.
The AC/DC bus imbalance measurements remained relatively stable
with only slight variations observed during the TCM-5 maneuver. All
other power-related and subsystem telemetry measurements were as expected.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.162 | GALILEO Update - July 26 | 26523::KLAES | All the Universe, or nothing! | Fri Jul 27 1990 13:47 | 96 |
| Date: 26 Jul 90 23:15:55 GMT
From: (Ron Baalke)
Subject: Galileo Update - 07/26/90
GALILEO
MISSION STATUS REPORT
July 26, 1990
As of noon (PDT) Thursday, July 26, 1990, the Galileo spacecraft
is 81,154,850 miles from Earth and traveling at a heliocentric
velocity of 50,620 miles per hour. The spacecraft is spinning at 3.15
rpm with a sun point angle of 4.7 degrees. Round trip light time is
14 minutes, 36 seconds.
Commands were sent on July 20 to disable the Plasma Wave (PWS)
magnetic field sensor/electronics heater control algorithm and to
power off the 3-watt thermal control heater. These actions were taken
to eliminate concerns for solder joint degradation due to higher than
expected heater on/off cycling observed over the past two weeks. A
comparison of actual flight temperature data with predicted
temperatures indicated that the heater can be safely powered off with
no risk to the PWS. A plan is being developed to determine how soon
after High Gain Antenna (HGA) deployment it will be safe to repower
the heater.
Attitude and Articulation Control Subsystem (AACS) acquisition
sensor threshold parameters were changed on July 20 as a result of
calibration data collected in June. The updated threshold levels are
consistent with expected signal amplitude levels for this mission phase.
The maneuver Profile Activity (PA) which previously had not
properly set the thruster temperature monitor bit has been fixed and
could cause a maneuver abort if the algorithm remained enabled. The
Retropropulsion Module (RPM) thruster temperature algorithm was
therefore disabled on July 23. This action was taken to assure that a
faulty transducer interface would not abort a burn activity and cause
safing of the spacecraft (Z1A, P1A, and L2B transducer interfaces have
already failed).
Late on July 19 and then again early on July 23, a recurrence of
the despun Command Data Subsystem (CDS) Critical Controller (CRC)
Power on Reset (POR) A telemetry indication was noticed in CDS
telemetry. The signature was the same as that observed in the
previous two occurrences in late February and late April of this year.
Recovery actions to reset the indications were taken on July 20 and
July 23, respectively. Actions were the same as for the previous two
CRC POR telemetry indications. After the command recovery actions,
NO-OP commands were sent to properly reset the Command Loss Timer.
There is no concern for the health of the Spacecraft as a result of
these POR telemetry indications.
The cause for the CRC A POR telemetry indication is presently
unknown, however several possibilities have been identified. One
promising explanation involves electrical noise coupling from 2.4khz
power interfaces to the despun CDS CRC POR A interface. These
interfaces are all routed through the Spin Bearing Assembly (SBA) and
are adjacently located. For noise coupling to occur, both brushes in
the CDS POR interface must momentarily (about 50 microseconds) present
a high resistance (greater than 10 kohm) in the interface and an AC
bus imbalance condition must exist. The Orbiter AC bus imbalance
telemetry has indicated the existence of AC bus imbalance since
December 1989. Ground test data on a flight-like slip ring assembly
has shown that high resistance can exist for greater than 1 msec even
after 1.3 million SBA revolutions. The number of inflight SBA
revolutions to date in the mission is about 1.1 million. If the noise
coupling model is valid and the flight slip rings perform similar to
the ground test assembly, it is reasonable to expect several more CDS
CRC A POR telemetry indications. Investigative actions into the other
possible causes are in process.
The AC/DC bus imbalance measurements remained relatively stable
with only slight variations observed. All other power-related and
subsystem telemetry measurements were as expected.
The AACS Flight Software must be changed to allow for the pulse
mode spin up to 10 rpm required for Probe Release and for Jupiter
Orbit Insertion which is to occur in December 1995. These changes
will not be uplinked to the spacecraft until much later in the
mission. To accommodate the required changes, the existing AACS
software must be scrubbed. Prior to launch, the project had developed
a set of possible scrubbs which will, if implemented, free up adequate
memory. The AACS Flight Software team has examined each of the scrubb
candidates in detail and has presented its recommendation to the
project in a series of meetings over the past several weeks. Total
unused memory after the implementation of the approved scrubbs is
expected to be 772 words. No existing functional capability has
sacrificed as a part of this scrubbing effort. Two additional scrubbs
which could yield an additional 190 words of memory have been deferred.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.163 | GALILEO Update - July 27 | 26523::KLAES | All the Universe, or nothing! | Mon Jul 30 1990 15:03 | 30 |
| Date: 27 Jul 90 22:54:04 GMT
From: (Ron Baalke)
Subject: Galileo Update - 07/27/90
GALILEO MISSION STATUS
July 27, 1990
The Galileo spacecraft is presently 80.6 million miles from
Earth, and more than 117 million miles from the Sun. Its speed in
solar orbit is 50,536 mph, and the round-trip communication time with
Earth is 14 minutes 27 seconds.
The spacecraft health and performance continue to be excellent.
The spacecraft's activity level is quiet since the successful
completion of the fifth Trajectory Correction Maneuver ten days ago.
Because of the still-increasing distance from the Sun and the
associated reduced angular speed, Sun-pointing maneuvers, once
performed every few days, now need to be done only about once a month.
The flight team is now planning the remaining maneuvers and
cruise sequences, together with the Earth science activities for the
early December Earth gravity-assist flyby.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.164 | GALILEO Update - August 2 | ADVAX::KLAES | All the Universe, or nothing! | Fri Aug 03 1990 20:14 | 50 |
| Date: 2 Aug 90 18:44:28 GMT
From: (Ron Baalke)
Subject: Galileo Update - 08/02/90
GALILEO
MISSION STATUS REPORT
August 2, 1990
As of noon (PST) Thursday, August 2, 1990, the Galileo spacecraft
is 77,440,900 miles from Earth and was traveling at a heliocentric
velocity of 50,110 miles per hour. The spacecraft continues its 3.15
rpm spin in dual spin mode. Round trip light time is 13 minutes, 56
seconds.
A NO-OP command was sent on July 30 to reset the Command Loss
Timer to 264 hours, the planned value for this mission phase.
Commands were sent on August 1 to change the variable telemetry
map replacing the Attitude and Articulation Control Subsystem (AACS)
trickle memory readout information with combined star code
information. This change allows the star code data to be telemetered
every spacecraft revolution (about 20 sec) rather than 260 seconds.
The star code data provides detailed information relating to the
functional operation of the SEQID algorithm. This detailed information
will be helpful in understanding the cause of some earlier minor
star-related anomalies. There is no concern for star scanner as a
result of these anomalies.
A Ultra Stable Oscillator (USO) test was conducted on August 1.
This test provides continuing trend information characterizing the
performance of this ultra-stable RF downlink source.
The AC/DC bus imbalance measurements remained relatively stable
with only slight variations observed. Over the last week the AC
measurement has fluctuated about 2 volts and remains stable near 48.6
volts. All other power-related and subsystem telemetry measurements
were as expected.
A total of 2065 real-time commands have been transmitted to
Galileo. Of these, 1060 have been pre-planned in the sequence design
and 1005 were not. In the past week, 9 real-time commands were
transmitted with one pre-planned.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.165 | GALILEO Updates - August 9-10 | ADVAX::KLAES | All the Universe, or nothing! | Mon Aug 13 1990 15:32 | 131 |
| Date: 10 Aug 90 06:15:19 GMT
From: (Ron Baalke)
Subject: Galileo Update - 08/09/90
GALILEO MISSION STATUS
August 9, 1990
The Galileo spacecraft is 73.5 million miles from Earth today,
with a round-trip communication time of 13 minutes 10 seconds. Its
orbital speed around the Sun is 49,750 mph.
The spacecraft health and performance continue to be excellent.
Last week it turned to move its spin axis from 9 degrees behind the
Sun to 10 degrees ahead, to keep the spacecraft body and the furled
high-gain antenna shaded from solar radiation. This is the largest
Sun-pointing maneuver Galileo has done. At this part of its orbit,
more than 118 million miles from the Sun and moving relatively slowly,
it is safe to do large Sun-pointing turns about once a month.
The flight team has completed, and the project has reviewed and
approved, the cruise profile plan for October 22 to December 7, the
operational period following the current sequence. From this plan, a
computer sequence will be constructed to control the spacecraft during
the full playback of Venus science data, checkout of the atmospheric
probe, and trajectory-correction maneuvers in preparation for the
Earth gravity assist on December 8.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
Date: 12 Aug 90 12:34:57 GMT
From: (Ron Baalke)
Subject: Galileo Update - 08/10/90
GALILEO
MISSION STATUS REPORT
August 10, 1990
As of noon (PDT) Friday, August 10, 1990, the Galileo spacecraft
is 73,477,330 miles from Earth and traveling at a heliocentric
velocity of 49,750 miles per hour. Round trip light time is 13
minutes, 14 seconds.
A SITURN was successfully performed on August 3. This turn,
about 19 degrees, was the largest turn to date. Spacecraft
performance for this activity was as expected and without incident.
The turn resulted in the spacecraft leading the sun by about 10 degrees.
A NO-OP command was sent on August 6 to reset the Command Loss
Timer to 264 hours, the planned value for this mission phase.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV) and Dust Detector (DDS) instruments
on August 3. Another DDS MRO was performed on August 9.
A command sequence was sent on August 6 to recover from the
Magnetometer (MAG) MRO anomaly identified several weeks ago. Recent
MAG data analysis indicated that the MRO anomaly was caused by a MAG
programming error which became evident under the unique conditions of
using the optimal averager for an extended time period. As part of the
MAG recovery, the MAG executive memory was totally reloaded and
verified and the microprocessor restarted via a main power off/on
cycle on August 6 and proper operation of the MAG electronics was
observed. The final MAG recovery action, a command to process data
from the outboard sensor occurred successfully on August 9. This
anomaly was the result of a unique set of circumstances. To better
understand the anomaly, a description of the operation of the
magnetometer is provided below.
During cruise when low telemetry rates are available, MAG data is
collected, stored and processed using the MAG optimal averager
capability which provides sensor averaged data to the Computer Data
Subsystem (CDS) for the downlink MRO. After each MAG MRO a command is
sent from the stored sequence to reset the optimal averager for
subsequent data collection. The MAG microprocessor writes this reset
command into the data stack portion of its memory. After this command
is issued 36 times, the data stack memory is overflowed and the reset
commands are stored in pointer area of MAG memory corrupting locations
used by the MAG executive program.
A Ultra Stable Oscillator (USO) test was conducted on August 9.
This test provides continuing trend information characterizing the
performance of this ultra-stable RF downlink frequency source.
The 16th Retropropulsion (RPM) "flushing" activity was
successfully performed on August 9. All 12 RPM thrusters were flushed
during the activity. Detailed thruster temperature profiles are not
available due to operation at 40 bps. Successful flushing was
inferred from other spacecraft telemetry measurements/events including
Attitude and Articulation Control Subsystem (AACS) performance and
thruster counts.
An EUV MRO was successfully performed on August 9 to collect
unique information regarding the presence of atomic helium and
hydrogen from the Comet Levy.
The AC/DC bus imbalance measurements remained relatively stable
with only slight variations observed. The AC measurement is stable
near 48.6 volts while the DC measurement is stable near 18.3 volts.
All other power-related telemetry and subsystem telemetry
measurements are normal.
The final cruise profile plan for Venus-Earth-9 (VE-9) was
reviewed and approved by Project on August 3. This sequence covers
the time period from October 22 to December 7 and contains numerous
events including Plasma Subsystem (PLS) shade retraction, probe
checkout, the playback of Venus data, and time windows for Trajectory
Course Maneuver (TCM-7, TCM-8 and TCM-8A) on November 13, November 28
and December 3, respectively. The VE-9 sequence also contains Earth
Science data collection which begins on November 8 and continues
throughout the sequence. Earth/Moon science data collection will also
continue as a part of the VE-11 sequences.
The 70 meter Australian track on August 1 was cut short when the
antenna had to be stowed due to high winds. Data lost included one
hour of USO test data and an hour and a half of ranging data. These
data losses were not considered significant and the remaining Deep
Space Network (DSN) tracking support was excellent.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.166 | GALILEO Update - August 16 | ADVAX::KLAES | All the Universe, or nothing! | Fri Aug 17 1990 15:15 | 25 |
| Date: 16 Aug 90 23:14:31 GMT
From: (Ron Baalke)
Subject: Galileo Update - 08/16/90
GALILEO MISSION STATUS
August 16, 1990
The Galileo spacecraft is 69.3 million miles from Earth, with a
round-trip communication time of 12 minutes 25 seconds. The spacecraft
must still travel more than 154 million miles in its orbit before it
reaches Earth for its gravity assist in early December. Speed in
orbit is currently more than 49,500 mph, and the distance to the Sun
is about 119 million miles, nearly a maximum for the present orbit.
Performance continues to be excellent. Operational activity this
week includes continuing cruise science data gathering, together with
continued engineering tests and other routine operations.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.167 | GALILEO Update - August 17 | ADVAX::KLAES | All the Universe, or nothing! | Mon Aug 20 1990 17:08 | 57 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/17/90
Date: 17 Aug 90 17:28:10 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
August 17, 1990
As of noon (PDT) Friday, August 17, 1990, the Galileo spacecraft
is 69,292,070 miles from Earth and traveling at a heliocentric
velocity of 49,540 miles per hour; distance to the Sun is 118,825,230
miles (1.26 AU). Galileo is in dual spin cruise mode and spinning at
3.15 rpm. Round trip light time is 12 minutes, 22 seconds.
A NO-OP command was sent on August 13 to reset the Command Loss
Timer to 264 hours, the planned value for this mission phase.
A special Magnetometer (MAG) Memory Readout (MRO) was
successfully performed on August 13. This MRO was the final
verification step in the MAG recovery process from the anomalous MRO
detected in June 1990. Proper operation of the MAG instrument has now
been verified. A flight software patch has been developed by the MAG
to preclude recurrence of the anomalous MRO and ground verification of
this patch is presently in process. No concern exists for the health
or operation of the MAG instrument with its present software load.
A Ultra Stable Oscillator (USO) test was conducted on August 16.
This test provides continuing trend information characterizing the
performance of this ultra-stable RF downlink frequency source.
The AC/DC bus imbalance measurements remained relatively stable
with some variation observed. The AC measurement dropped about 3
volts from 48.6 to 45.8 volts. This drop occurred during a planned
Deep Space Network (DSN) non-tracking period. Review of other
spacecraft telemetry revealed no changes in other measurements and all
readings were normal. The DC measurement remained stable near 18.3 volts.
An Extreme Ultraviolet Spectrometer (EUV) MRO was successfully
performed on August 16 to continue collection of data from Comet Levy.
Last week's MRO clearly identified the presence of hydrogen in the
coma. This MRO will capture observations of the comet's tail.
Time has been requested for the 34 meter antenna in Goldstone,
California, (DSS-15) to perform detailed measurements of the X-Band
uplink frequency stability. These measurements are intended to
provide precise information regarding the DSN X-Band uplink
capabilities to support the Galileo Gravity Wave Experiment.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.168 | GALILEO Update - August 23 | ADVAX::KLAES | All the Universe, or nothing! | Fri Aug 24 1990 16:10 | 30 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/23/90
Date: 23 Aug 90 21:23:17 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
August 23, 1990
The spacecraft is now 65 million miles from Earth, closing at
about 640,000 miles per day. The round-trip communication time is 11
minutes 38 seconds.
Today Galileo moves through aphelion, the farthest point from the
Sun in its present orbit; its solar distance is just under 120 million
miles, and the speed in orbit is 49,467 mph, a minimum.
Spacecraft health and performance continue to be excellent, and
the activity level quiet, with cruise science data-gathering and
routine engineering tests and calibrations. The next Sun-point
maneuver is in early September, the next trajectory-correction
maneuver in October.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.169 | GALILEO Update - August 24 | ADVAX::KLAES | All the Universe, or nothing! | Mon Aug 27 1990 15:00 | 69 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/24/90
Date: 24 Aug 90 16:53:46 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
August 24, 1990
As of noon (PDT) Thursday, August 23, 1990, the Galileo
spacecraft is 64,920,520 miles from Earth and traveling at a
Heliocentric speed of 49,470 miles per hour; distance to the Sun is
118,947,090 miles (1.28 AU). The spacecraft is spinning at 3.15 rpm
and the downlink telemetry rate through the Low Gain Antenna (LGA) is
40 bits per second. Round trip light time is 11 minutes, 42 seconds.
A NO-OP command was sent on August 20 to reset the Command Loss
Timer to 264 hours, the planned value for this mission phase.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Dust Detector (DDS) and
Magnetometer (MAG) instruments on August 20 and August 22.
A Ultra Stable Oscillator (USO) test was conducted on August 21.
This test provides continuing trend information characterizing the
performance of this ultra-stable RF downlink frequency source.
The delta DOR function in the Radio Frequecny Subsystem (RFS) was
activated again on August 21. Delta DOR is another navigation data
source in addition to doppler and ranging data already available. The
S-band delta DOR consists of modulating the downlink carrier with a
3.82 MHz sine wave. When delta DOR is active, the spacecraft telemetry
data stream from the Telemetry Modulation Unit (TMU) is interrupted
and no spacecraft data is transmitted. This delta DOR activity was the
first of ten planned prior to Earth flyby to enhance the Orbit
Determination (OD) solution. Preliminary analysis indicates data
collection was unsuccessful due to hardware failures at the 70 meter
stations at Goldstone (DSS 14) and Spain (DSS 63). The loss of this
single delta DOR activity is not a serious concern to Galileo because
doppler and ranging data are available and other delta DOR data
collection opportunities are scheduled. The next opportunity is
planned for September 6.
The Attitude and Articulation Control Subsystem (AACS) began
planned periodic calibration of the acquisition sensor on August 22.
The data collection process (sensor output signal amplitude vs.
off-sun angle) used for calibration will be completed by August 27.
The AC/DC bus imbalance measurements were stable with little
variations observed. The AC measurement is stable at 48.2 volts while
the DC measurement is stable at 18.7 volts an increase of 0.4 volt.
The Project has started a series of ad-hoc meetings to
define/plan the test and training approach in preparation for Earth 1
mission activities. The significant new activities for the Flight
Team include high rate data handling and rapid Deep Space Network
(DSN) tracking and station handovers near the time of Earth closest
approach. The test and training plan will take advantage of Mission
Readiness Tests (MRTs) already scheduled by the DSN in order to
minimize requirements for DSN station support.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.170 | GALILEO Update - August 30 | ADVAX::KLAES | All the Universe, or nothing! | Fri Aug 31 1990 14:08 | 79 |
| Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/30/90
Date: 30 Aug 90 18:45:31 GMT
Reply-To: baalke@mars.jpl.nasa.gov (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
August 30, 1990
As of noon (PDT) Thursday, August 30, 1990, the Galileo
spacecraft is 60,407,550 miles from Earth and traveling at a
heliocentric speed of 49,540 miles per hour; distance to the Sun is
118,826,450 miles (1.27 AU). The spacecraft is spinning at 3.15 rpm in
dual spin mode, with an attitude Sun point angle of 5.8 degrees.
Round trip light time is 10 minutes, 54 seconds.
A NO-OP command was sent on August 27 to reset the Command Loss
Timer to 264 hours, the planned value for this mission phase.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Dust Detector (DDS) and
Magnetometer (MAG) instruments on August 27 and 30. The data
collection for the periodically planned Attitude and Articulation
Control Subsystem (AACS) acquisition sensor calibration was completed
on August 27.
Telecommunication system tests were performed on August 24 and 27.
The two Radio Frequency Subsystem (RFS) tests, the Tracking Loop
Capacitor and the Automatic Gain Control tests (RFS TLC and RFS AGC)
are performed periodically to collect trend information characterizing
the performance of the S-Band RF receiver. In addition to the RF
tests, Signal-to-Noise Ratio (SNR) performance trend data was also
collected for the digital Command Detector Unit (CDU) used to detect
command data bits and route them to the Command Data Subsystem (CDS).
A star vector update was successfully performed on August 27.
This updated star information will be used for the forthcoming
"sun-point" activities later in the Venus-Earth-5 (VE-5) stored
sequence.
The 17th Retropropulsion Module (RPM) "flushing" activity was
successfully performed on August 30. All 12 RPM thrusters were
flushed during the activity. Detailed thruster temperature profiles
are not available due to operation at 40 bits/second. Successful
flushing was inferred from other spacecraft telemetry
measurements/events including AACS performance and thruster counts.
The AC/DC bus imbalance measurements remained relatively stable
with only slight variations observed. The AC measurement is stable
near 48.5 volts while the DC measurement is stable near 18.6 volts.
All other power-related and subsystem telemetry measurements are normal.
The VE-11 Cruise Plan was approved on August 27. The VE-11
sequence covers the period from December 7 (Earth - 1 day) to December
17 (Earth + 9 days). The VE-11 file will be revalidated. This extra
step in the process is required because of the large number of
changes, identified at a review meeting, which were to be incorporated
into the sequence prior to its delivery to the Sequence Team. This is
the most complex sequence designed to date.
The Deep Space Network (DSN) has initiated a study of the
dynamics of the radio metric data conditions surrounding Earth Gravity
Assist (EGA1) to optimize the tracking procedures and parameters for
these short, but critical near Earth passes. High doppler rates and
spacecraft antenna switching during the station transfer periods,
together with the Project's desire for 2-way doppler for radio science
purpose, present several competing requirements for evaluation. The
DSN has been requested to take particular care with the remaining
delta DOR passes in view of the failure of the first two attempts and
the value of the data type to EGA1 navigation enhancement.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.171 | Earth Fly By | 42399::CHRIS | Capacity! What Capacity ? | Sat Sep 01 1990 16:06 | 4 |
| Are NASA planning to observe the Earth during the flyby as they would
any other planet ?
Chris
|
| 560.172 | Fly byS | 4347::GRIFFIN | Dave Griffin | Mon Sep 03 1990 01:07 | 15 |
| Yes, it will. I don't have a lot of details though.
On the first earth encounter it will be taking images of the the
earth and the lit/unlit sides of the moon. Because of the short
range, Galileo will be able to send data at high rates using the
low-gain antennas (the big hi-gain antenna is still furled).
During second encounter all of Galileo's instruments will be used on
earth -- more of a test of the instrumentation than a scientific probe
(provides comparisions of data that was collected at Venus, and the
data that will be collected at Jupiter), but some Earth studies are
planned. There is also a chance that Galileo will be able to record
the motion of the moon as it orbits the earth.
- dave
|
| 560.173 | GALILEO Update - August 31 | ADVAX::KLAES | All the Universe, or nothing! | Tue Sep 04 1990 15:35 | 30 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/31/90
Date: 1 Sep 90 18:28:10 GMT
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
August 31, 1990
The Galileo spacecraft is currently 59.8 million miles from
Earth; round-trip communication time is 10 minutes 43 seconds. Speed
in orbit is 49,560 mph, increasing slowly as the distance from the
Sun (118.8 million miles today) gradually shortens.
The spacecraft health and performance continue to be excellent
amid routine, relatively quiet operations. Yesterday the propulsion
system performed its scheduled maintenance (in which the thrusters
perform minimum pulses to flush the lines and valves). A Sun-point
maneuver comes next Tuesday; it will point the spacecraft about 10
degrees ahead of the Sun, to stay shaded as it orbits for another
month. In addition, cosmic dust, ultraviolet and magnetic field data
are being collected continuously and read out every few days.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.174 | Earth/Moon Encounter Science | 15372::LEPAGE | Caught between Iraq & a hard place | Fri Sep 07 1990 15:09 | 16 |
| Re:.171
As .172 indicated, Galileo will observe the Earth and Moon during
its two flybys. Galileo's UV and IR spectrometers will be used to study
the Earth's ozone distribution, the presence of mesospheric water,
trace gases, and the geocorona. Galileo's IR spectrometer and cameras
will be used on the Moon to map some of the poorly mapped areas of the
Moon's southern polar regions, look for water, and study the surface
minerology on its lead hemisphere around Mare Oriental. Galileo's radio
transmissions will also be used to make very accurate determinations of
the masses of the Earth and Moon. And of course, Galileo's cameras will
be used to take PR pictures of the Earth and Moon which can be put
together to make movies of the Moon orbiting the Earth.
Drew
|
| 560.175 | GALILEO Update - September 6 | ADVAX::KLAES | All the Universe, or nothing! | Mon Sep 10 1990 17:47 | 64 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/06/90
Date: 6 Sep 90 23:39:21 GMT
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
September 6, 1990
As of noon (PDT) Thursday, September 6, 1990, the Galileo
spacecraft is 55,791,470 miles from Earth and traveling at a
heliocentric speed of 49,755 miles per hour; distance to the Sun is
118,463,405 miles (1.26 AU). The spacecraft continues it 3.15 rpm spin
in dual spin mode and the downlink telemetry is at 40 bps. Round trip
light time is 10 minutes, 4 seconds.
A SITURN was successfully performed on September 4. This turn was
about 17 degrees. Spacecraft performance throughout this activity was
as expected; there were no problems. The turn resulted in the
spacecraft leading the sun by about 8.5 degrees.
A NO-OP command was sent on September 4 to reset the Command Loss
Timer to 264 hours, the planned value for this mission phase.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet (EUV), Dust Detector (DDS) and
Magnetometer (MAG) instruments on September 4 and 6.
The data collection for the periodically planned Attitude and
Articulation Control Subsystem (AACS) spin detector sensor calibration
was completed on September 6.
A Ultra Stable Oscillator (USO) test was conducted on August 31.
This test provides continuing trend information characterizing the
performance of the ultra-stable RF downlink frequency source.
A North/South delta DOR using the 70 meter antennas in Goldstone
and Australia was conducted on September 6. Delta DOR is an
additional navigation data source in addition to doppler and ranging
data. When the Delta DOR signal is modulating the downlink carrier
spacecraft telemetry data from the Telemetry Modulation Unit (TMU) is
interrupted; no spacecraft telemetry data is transmitted during this
interruption. This Delta DOR was successful; it is the third of 10
Delta DOR data gathering activities prior to the Earth closest approach.
The AC/DC bus imbalance measurements remained relatively stable
with only slight variations observed. The AC measurement is stable
near 47.6 volts while the DC measurement is stable near 18.6 volts.
All other power-related and subsystem telemetry measurements are normal.
Ultraviolet Spectrometer (UVS) Lyman Alpha data gathering
continued on September 4. This data is stored on the spacecraft tape
recorder for replay along with the Venus Encounter data planned for
November 19-21. This is the fifth of eight UVS Lyman Alpha data
gathering sequences in the Venus-Earth-5 (VE-5) sequence.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.176 | GALILEO Update - September 10 | ADVAX::KLAES | All the Universe, or nothing! | Thu Sep 13 1990 15:12 | 31 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/10/90
Date: 10 Sep 90 22:46:50 GMT
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
September 10, 1990
The Galileo spacecraft is 53.1 million miles from Earth, with a
little less than three months and about 125 million miles to travel in
orbit before the first Earth gravity assist on December 8. Speed in
orbit is 49,950 mph. Round-trip communication time is 9 minutes 31
seconds.
The spacecraft status and performance continue to be excellent
during the relatively low level of activity of the current cruise
mode. Last Tuesday Galileo performed a Sun-point maneuver (actually
going from roughly 8 degrees "behind" the Sun direction to 8 degrees
"ahead") to maintain shading and therefore moderate temperatures for
its equipment. This programmed task was a long-planned part of the
current Venus-Earth operational sequence, which began controlling
spacecraft functions June 11 and will continue through mid-October.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.177 | GALILEO Update - September 13 | ADVAX::KLAES | All the Universe, or nothing! | Fri Sep 14 1990 16:22 | 68 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/13/90
Date: 13 Sep 90 23:14:12 GMT
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
September 13, 1990
As of noon (PDT) Thursday, September 13, 1990, the Galileo
spacecraft is 51,102,490 miles from Earth and traveling at a
heliocentric speed of 50,110 miles per hour; distance to the Sun is
117, 858,250 miles (1.26 AU). The spacecraft's spin rate continues at
3.15 rpm in dual spin configuration. The spacecraft attitude sun point
angle is at 3.4 degrees. Round trip light time is 9 minutes, 14 seconds.
A NO-OP command was sent on September 10 to reset the Command
Loss Timer to 264 hours, the planned value for this mission phase. A
total of 2155 real-time commands have been transmitted to Galileo. Of
these, 1066 have been pre-planned in the sequence design and 1089 were not.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS)
and Magnetometer (MAG) instruments on September 10 and 13.
An Ultra Stable Oscillator (USO) test was conducted on September
7 and 10. This test provides continuing trend information
characterizing the performance of the ultra-stable RF downlink
frequency source.
The Energetic Particles Detector (EPD) instrument was turned on
and the motor successfully stepped on September 13 as part of its
motor maintenance activity. During this activity the EPD was stepped
through all seven sectors ten times then back to its original Sector 4
position. During this activity the EPD operation was as expected and
without incident.
The AC/DC bus imbalance measurements remained relatively stable
with only slight variations observed. The AC measurement is stable
near 48.6 volts while the DC measurement is stable near 18.6 volts.
All other power-related and subsystem telemetry measurements are normal.
Key events related to the German Space Operations Center (GSOC)
Uplink Compatibility Test planned for September 24/26 were completed
this week. On Monday (September 10th) a "dry run" of the test was
successfully completed which included checkout of the voice link and
protocols between the GSOC Control Center and the JPL Mission Support
Area (MSA) and final validation of GSOC and the Weilheim tracking
station. The "dry run" exercised the Sequence of Events for the test
and included loading and transmitting (to a water load) of the command
file to be used in the test. No significant issues were identified
during a pre-test meeting on September 13th to review the status of
test preparation. The objective of the Uplink Compatibility Test is
to validate the uplink command interface between the GSOC Weilheim
Tracking Station and the Galileo Spacecraft. GSOC/Weilheim will
support the Galileo Cruise Science mission starting in September 1991
by generating Experiment Data Records (EDRs) and uplinking
non-interactive commands for the Low Rate Science (LRS) Fields and
Particles (F&P) instruments.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.178 | GALILEO Update - September 20 | ADVAX::KLAES | All the Universe, or nothing! | Fri Sep 21 1990 15:57 | 104 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/20/90
Date: 20 Sep 90 21:57:29 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
September 20, 1990
As of noon (PDT) Thursday, September 20, 1990, the Galileo
spacecraft is 46,377,170 miles from Earth and traveling at a
heliocentric speed of 50,610 miles per hour; distance to the Sun is
117,011,560 miles (1.25 AU). The spacecraft continues to spin at 3.15
rpm in dual spin configuration. Round trip light time is 8 minutes, 22
seconds.
A NO-OP command was sent on September 17 to reset the Command
Loss Timer to 264 hours, the planned value for this mission phase.
Cruise Science Memory Readouts (MROs) were successfully performed
for the Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS)
and Magnetometer (MAG) instruments on September 17 and 20.
Another Ultra Stable Oscillator (USO) test was conducted on
September 19. This test provides continuing trend information
characterizing the performance of the ultra-stable RF downlink
frequency source.
A star vector update was successfully completed on September 17.
This updated star information will be used for the forthcoming
activities later in the Venus Earth-5 (VE-5) stored sequence.
Early on September 18, the fifth occurrence of the despun Command
Data Subsystem (CDS) Critical Controller (CRC) A Power on Reset (POR)
was observed in CDS telemetry. The signature was the same as that
observed in the previous occurrences in February, April and July 1990.
Recovery actions to reset the telemetry indication were taken within
4 hours and were successfully performed. After the recovery actions,
a NO-OP command was sent to properly reset the Command Loss Timer in
both halves of the CDS. There is no concern for the health of the
spacecraft as a result of these POR telemetry indications.
The investigating team troubleshooting the despun CDS Critical
Controller A POR anomaly has dropped noise coupling from its list of
possible causes based on recent test data using flight-like hardware.
Earlier laboratory tests performed in May 1990 indicated it was
feasible to generate a POR telemetry indication if:
(a) one side of the AC power bus was shorted to chassis
(b) a high resistance (greater than or equal to 10K
ohms) was present in the slip ring interface and
(c) an equivalent coupling capacitance of greater than
or equal to 200 pf is available
Recently tests were conducted using a flight-like slip ring
module and a wiring configuration to maximize capacitive coupling.
The test results demonstrated that there was insufficient noise
coupling (factor of 8) to produce a POR signal.
Other possible causes include a faulty solder joint, electronic
part failures, marginal component performance, incorrect component
value in the CDS despun filter and slip ring debris. The slip ring
debris is still be carried as a possibility because it cannot be
totally discounted, however, no effort is being spent on further
evaluation of slip ring debris.
The 18th Retro Propulsion Module (RPM) "flushing" activity was
successfully performed on September 20. All 12 RPM thrusters were
flushed during the activity. Detailed thruster temperature profiles
are not available due to operation at 40 bps. Successful flushing was
inferred from other spacecraft telemetry measurements/events including
Attitude and Articulation Control Subsystem (AACS) performance and
thruster counts.
An unexpected command in-lock indication was observed in CDS
telemetry on September 13. This unexpected situation is presently
under investigation.
The AC/DC bus imbalance measurements remained relatively stable
with only slight variations observed. The AC measurement is stable
near 48.6 volts while the DC measurement is stable near 18.6 volts.
All other power-related and subsystem telemetry measurements are normal.
The sixth of eight Ultraviolet Subsystem (UVS) Lyman Alpha data
collection activities planned for VE-5 was completed on September 20.
All UVS Lyman Alpha data collected during cruise will be played back
in VE-9.
The Project has accepted the Deep Space Network (DSN) and FCSO
recommendation that the spacecraft transponder be in the non-coherent
mode during the Earth closest approach phase. Although this strategy
will preclude collecting some two-way Doppler data for Radio Science,
it will afford the highest confidence of maintaining downlink receiver
lock during the critical closest approach phase.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.179 | GALILEO Update - September 24 | ADVAX::KLAES | All the Universe, or nothing! | Tue Sep 25 1990 14:35 | 34 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/24/90
Date: 24 Sep 90 22:52:32 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
September 24, 1990
The Galileo spacecraft is now 43.7 million miles from Earth; the
distance is shortening by more than 670,000 miles per day, although
the actual speed in orbit is almost 51,000 mph, more than 1.2 million
miles per day. Round-trip communication time is 7 minutes 50 seconds.
Galileo's performance and spacecraft health continue to be
excellent. Last week the small thrusters used to perform maneuvers
were cleaned out by flushing minimal amounts of propellants through
each system; this routine maintenance is scheduled about every three
weeks. Other routine engineering operations and tests, and cruise
science data collection and playback, are also continuing.
The flight team and project office are currently at work planning
the science observations during the Earth gravity assist in early
December, the trajectory-correction maneuver scheduled for October 9,
and the interplanetary cruise operations leading to the Earth flyby.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.180 | GALILEO Update - September 28 | ADVAX::KLAES | All the Universe, or nothing! | Tue Oct 02 1990 16:50 | 60 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/28/90
Date: 28 Sep 90 23:58:40 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
September 28, 1990
The Galileo spacecraft is about 41 million miles from Earth
today; round-trip communication time is 7 minutes 21 seconds. The
spacecraft has traveled 544 million miles since launch last October
18, and has about 103 million to go before the Earth gravity assist
this coming December 8; the Jupiter encounter is some 1.8 billion
miles and more than five years ahead. Speed in orbit is currently
51,368 mph.
This week the project successfully completed two uplink
compatibility tests with the German Space Operation Center (GSOC),
using the Weilheim tracking station. GSOC and Weilheim will support
Galileo cruise activities beginning in September 1991.
Otherwise, performance and spacecraft health continue to be
excellent. The flight team continues to prepare command sequences for
the next maneuver (scheduled for October 9), the next cruise sequence,
and the Earth science observations.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.astro
Subject: Re: Galileo gravity assist
Date: 1 Oct 90 14:50:52 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
In article <1990Sep29.231751.18892@watcsc.waterloo.edu> death@watcsc.
waterloo.edu (Trevor Green) writes:
>Just out of curiosity (definitely not out of financial ability), what
>part of Earth is going to get to see Galileo go by this Dec. 8? How
>about the next time?
Both Earth flybys by Galileo (December 8, 1990 and December 8,
1992) will be over Africa.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.181 | GALILEO Update - September 27 | ADVAX::KLAES | All the Universe, or nothing! | Wed Oct 03 1990 17:57 | 108 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/27/90
Date: 3 Oct 90 04:16:53 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
September 27, 1990
As of noon (PDT) Thursday, September 27, 1990, the Galileo
spacecraft is 41,661,100 miles from Earth and was traveling at a
heliocentric speed of 51,260 miles per hour; distance to the Sun is
115,924,200 miles (1.24 AU). The downlink telemetry rate is at 40
bits/second through the LGA (Low Gain Antenna), and the spacecraft is
spinning at 3.15 rpm. Round trip light time is 7 minutes, 32 seconds.
A NO-OP command was sent on September 24 to reset the Command
Loss Timer to 264 hours, the planned value for this mission phase.
A second North/South delta Differential One-way Ranging (DOR)
using the 70 meter antennas in Goldstone and Australia was
successfully conducted on September 21. This delta DOR activity was
the fourth of 17 delta DOR data gathering activities planned prior to
the Earth closest approach. Delta DOR is an additional navigation
data source in addition to doppler and ranging data. When the delta
DOR signal is modulating the downlink carrier spacecraft telemetry
data from the TMU (Telemetry Modulation Unit) is interrupted; no
spacecraft telemetry is transmitted during this interruption. The
next delta DOR activity is scheduled for October 8 using the same two
70 meter antennas.
A set of 8 DACs (Delayed Action Commands) were sent on September
24. The DACs included commands to properly configure the transponder
in the RFS (Radio Frequency Subsystem) in preparation for the planned
GSOC (German Space Operation Center) uplink compatibility test later
on September 24 and 26.
The two GSOC/Weilheim Uplink Compatibility Tests were
successfully completed this week. During each test 16 NOP (No
operation) commands were transmitted to the spacecraft from the German
Weilheim tracking station under control of the German Space Operation
Center. The two tests were identical except that ranging modulation
was on the uplink for the second test. The Galileo Flight Team in the
MSA (Mission Support Area) at JPL used downlink telemetry via the DSN
(Deep Space Network) Madrid tracking station to confirm proper command
acceptance and execution by the spacecraft. GSOC will support the
cruise science phase of the Galileo mission starting in September 1991
by tracking the spacecraft 5 passes each week, generating EDRs
(Experiment Data Records) and transmitting non-interactive commands
for the F&P (Fields and Particles) LRS (Low Rate Science) instruments.
Cruise Science Memory Readouts (MROs) were successfully performed
for the EUV (Extreme Ultraviolet Spectrometer), DDS (Dust Detector)
and MAG (Magnetometer) instruments on September 25 and 27.
Near the beginning of the Australian 70 meter track on Sunday,
September 23, the sixth occurrence of the despun CDS (Command Data
Subsystem) CRC A (Critical Controller A) POR (Power on Reset) was
observed in CDS telemetry. The signature was the same as that
observed in the previous occurrences in February, April, July and
September of this year.
Recovery actions to reset the telemetry indication were taken
about 27 hours later. Due to the non time critical nature of
resetting this indicator and the very short tracking pass on Sunday,
it was decided to implement the recovery actions on September 24.
After the recovery actions, a NO-OP command was set to properly reset
the Command Loss Timer in both halves of the CDS. There is no concern for
the health of the spacecraft as a result of these telemetry indications.
The despun CDS POR telemetry indication is a latched signal
generated by electronic circuitry normally used to inhibit Despun
Critical Controller commanding when a real POR signal is present.
However, problems in the electronic circuitry or in the telemetry
latch device could produce an anomalous telemetry indication. The
circuitry used in this application is simple, has few components and
responds in 50-100 microseconds. The time duration of the "signal"
triggering the anomalous spacecraft event is unknown. In all
occurrences recovery from the POR telemetry indication was completely
successful indicating the anomalous event was not caused by a
permanent failure in the CDS.
The CDS personnel are in process of developing a method to
determine whether the telemetry latch device is "faulty" or the
circuitry is actually detecting a transient "POR signal" on the
interface. A report to the Project is planned for mid-October 1990 to
discuss the value/risk of this CDS effort.
Another USO (Ultra Stable Oscillator) test was conducted on
September 25. This test provides continuing trend information
characterizing the performance of the ultra-stable RF downlink
frequency source.
The AC/DC bus imbalance measurements exhibited some activity.
The AC measurement dropped about 12DN from 48.6 volts to 46.1 volts;
the DC measurement increased 2 DN to 18.8 volts. These changes
occurred during a quiescent period with no spacecraft activity. All
other power-related and subsystem telemetry measurements are normal.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.182 | GALILEO Update - October 4 | ADVAX::KLAES | All the Universe, or nothing! | Fri Oct 05 1990 18:10 | 91 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/04/90
Date: 4 Oct 90 22:54:25 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO
MISSION STATUS REPORT
October 4, 1990
As of noon (PDT) Thursday, October 4, 1990, the Galileo
spacecraft is 36,992,700 miles from Earth and was traveling at a
heliocentric speed of 52,060 miles per hour; distance to the Sun is
114,597,470 miles (1.23 AU). Galileo continues to spin at 3.15 rpm in
dual spin configuration. Round trip light time is 6 minutes, 42 seconds.
A NO-OP command was sent on October 1 to reset the Command Loss
Timer to 264 hours, the planned value for this mission phase.
Cruise Science Memory Readouts (MROs) were successfully performed
for the EUV (Extreme Ultraviolet Spectrometer), DDS (Dust Detector)
and MAG (Magnetometer) instruments on October 1 and 4.
Another USO (Ultra Stable Oscillator) test was conducted on
October 1. This test provides continuing trend information
characterizing the performance of the ultra-stable RF downlink
frequency source.
Commands were sent to extend the AACS (Attitude and Articulation
Control Subsystem )memory checksum range limits on October 1. The
updated range limits were extended in off-line memory. With these new
limits the AACS performs memory checksums over 96 percent of its
addressable off-line memory and 83 percent of the addressable on-line
memory. AACS continuously runs its checksum program in the background
and telemeters the result in AACS status data. No autonomous on-board
action is taken in response to an incorrect checksum, however, a flag
is set by AACS and telemetered.
UVS (Ultraviolet Spectrometer) Lyman Alpha data gathering
continued on October 4. This data is stored on the spacecraft tape
recorder for playback along with the Venus Encounter data planned for
November 19-21. This is the sixth of eight UVS Lyman Alpha gathering
activities in the VE-5 (Venus-Earth 5) sequence.
A SITURN to lead the sun was successfully performed on October 4.
This turn was about 19 degrees. Spacecraft performance throughout
the activity was normal and without incident. The turn resulted in
the spacecraft leading the sun by about 10 degrees.
Sometime between the end of the DSN (Deep Space Network) track on
October 1 and the start of track on October 2, the seventh despun CDS
(Command Data Subsystem) Critical Controller A POR (Power on Reset)
telemetry indication occurred. The signature was the same as that
observed in the previous six occurrences. Recovery actions to reset
the telemetry indication were completed less than 3 hours later.
Recovery actions were successfully completed and a NO-OP command was
sent to properly reset the Command Loss Timer in both halves of the CDS.
The AC/DC bus imbalance measurements exhibited some minor
activity. The AC measurement toggled 1 to 2 DN and fairly stable near
46.5 volts. The DC measurement increased 2 DN to about 18.9 volts.
All other power-related and subsystem telemetry measurements are normal.
The Project reviewed and approved the Preliminary sequence and
command generation product for the VE-9 sequence on September 28.
Final product approval is planned for October 9.
The Project also reviewed and approved the TCM-6 (Trajectory
Course Maneuver 6) design requirements and implementation on October
1. The TCM-6 maneuver will be executed on October 9 using the axial
(Z) thrusters and the lateral (L) thrusters to achieve the required
delta velocity increment of 0.51 meters/sec. Maneuver command uplink
approval is on-schedule for October 5, with uplink transmission on
October 8.
The Project reviewed and approved the Profile design sequence
product on October 1 for the VE-11 Earth encounter sequence. Also
reviewed and approved was the VE-12 Cruise Plan on October 3 with some
work items related to cruise science data return. These items mainly
resulted from the unavailability of acceptable star sets from January
18 thru February 13. Because of this condition, the spacecraft will
be operated in all-spin using sun acquisitions to maintain sun point.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.183 | GALILEO Update - October 5 | ADVAX::KLAES | All the Universe, or nothing! | Mon Oct 08 1990 14:00 | 37 |
| Date: 5 Oct 90 23:06:49 GMT
From: (Ron Baalke)
Subject: Galileo Update - 10/05/90
GALILEO MISSION STATUS
October 5, 1990
The Galileo spacecraft is 36.3 million miles from Earth today;
the round-trip communication time is 6 1/2 minutes. Speed in orbit is
52,187 mph.
Yesterday, on schedule, the spacecraft turned its spin axis from
about 9 degrees behind the Sun direction to 10 degrees leading it. It
takes about a month now for the Sun, as seen from Galileo, to move through
a 19-degree arc; the spacecraft turns in this fashion periodically to
keep its sensitive parts behind the protective sunshades.
Last Monday (October 1) the Project reviewed and approved the
design of the trajectory correction maneuver scheduled for next
Tuesday, October 9; approval of the command transmission occurs today.
The maneuver will change Galileo's velocity by 0.51 meter per second,
or about 1.1 mph.
Mission performance and spacecraft health continue to be
excellent. In addition to the Sun-pointing turn, the spacecraft
continues to collect ultraviolet and fields-and-particles information.
The flight team continues to carry out planned engineering tests and
to work on spacecraft operating sequences for the periods before,
during, and after the Earth gravity assist in December.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.184 | GALILEO Update - October 11 | ADVAX::KLAES | All the Universe, or nothing! | Fri Oct 12 1990 13:33 | 117 |
| Date: 11 Oct 90 23:42:01 GMT
From: (Ron Baalke)
Subject: Galileo Update - 10/11/90
GALILEO
MISSION STATUS REPORT
October 11, 1990
As of noon (PDT) Thursday, October 11, 1990, the Galileo
spacecraft is 32,399,810 miles from Earth and traveling at a
heliocentric speed of 53,010 miles per hour; distance to the Sun is
113,033,200 miles (1.22 AU). The spacecraft is spinning at 3.15 rpm
with a Sun point angle of 5.6 degrees. Round trip light time is 5
minutes, 52 seconds.
Sometime between the end of the DSN (Deep Space Network) track on
October 4 and the start of track on October 5, the eighth despun CDS
(Command Data Subsystem) Critical Controller A POR (Power on Reset)
telemetry indication was observed. The signature was the same as that
observed in the previous seven occurrences. Due to the weekend,
recovery actions to reset the telemetry indication were completed the
following Monday, October 8. Recovery actions were successfully
completed and a NO-OP command was sent to reset the Command Loss Timer
to 264 hours, the planned value for this mission phase.
Two delta DOR (Differential One-way Ranging) activities were
successfully completed on October 8 and 10, one prior to and one
after TCM-6 (Trajectory Course Maneuver 6) on October 9. These two
activities were both North/South passes using the 70 meter antennas in
Goldstone and Australia; and were the fifth and sixth of 17 planned
prior to Earth closest approach. Delta DOR is an additional
navigation data source in addition to doppler and ranging data. When
the delta DOR signal is modulating the downlink carrier, spacecraft
telemetry data from the TMU (Telemetry Modulation Unit) is interrupted;
no spacecraft telemetry is transmitted during this interruption.
Another USO (Ultra Stable Oscillator) test was conducted on
October 8. This test provides continuing trend information
characterizing the performance of the ultra-stable RF downlink
frequency source.
Cruise Science Memory Readouts (MROs) were successfully performed
for the EUV (Extreme Ultraviolet Spectrometer), DDS (Dust Detector)
and MAG (Magnetometer) instruments on October 8.
The TCM-6 maneuver sequence memory load was successfully
transmitted and received by the spacecraft on October 8. The maneuver
was executed, as planned, on October 9. The first burn segment was
completed without incident using the axial (z) thrusters. A
preliminary navigation assessment indicates a small overburn of about
0.8 percent compared with the nearly 2 percent overburn for TCM-5.
The TCM-6 maneuver was the first axial burn design incorporating the
performance results observed in TCM-1 and TCM-5. The second burn
segment using the lateral (L) thrusters was also completed
successfully without incident. Due to Earth look angle considerations,
it is not possible to reliably assess the total affect of lateral
burn. Subsequent orbit determination data will provide an assessment
of the total maneuver.
Spacecraft performance during the maneuver was excellent. All RPM
(Retro Propulsion Module) pressures and temperatures were near
expected levels; the thruster temperature profiles were similar to
those of previous burns. The L2B thruster temperature was inferred
from the cluster temperature sensor readings. No unexpected cluster
temperatures were observed. After the axial burn segment, the
sequence allowed time for a spin rate correction and pointing error
correction; neither correction was necessary since the attitude
excursions were small (less than 4 mrad) for both burn segments.
Commands were sent on October 11 to reconfigure the CDS spun
hardware via critical controller commands to enable the telemetry data
rate (1200 bps) switch planned for October 16. This series of commands
also configured the CDS to route 40 bps uncoded data to the TMU low
rate channel for downlink transmission.
Commands to update the star vectors were sent on October 8. This
updated star information will be used for the forthcoming activities
later in the VE-5 (Venus-Earth 5) stored sequence.
The 19th RPM flushing activity was successfully performed on
October 11. All thrusters were flushed during this activity except the
P-thrusters which were last used for the October 4 sunpoint activity.
Detailed thruster temperature profiles are not available due to
operation at 40 bps. Successful flushing was inferred from other
spacecraft telemetry measurements/events including AACS (Attitude and
Articulation Control Subsystem) performance and thruster counts.
The AC/DC bus imbalance measurements exhibited some activity.
The AC measurement increased 15DN during a period of no spacecraft
activity, about 12 hours prior to TCM-6 and then dropped about 12DN
several hours after TCM-6, and is stable near 48.6 volts. The DC
measurement began acting erratically about 30 hours after TCM-6 with
fluctuations up to 65DN and is near 19.8 volts. All other
power-related and subsystem telemetry measurements are normal.
The Project reviewed and approved the TCM-6 maneuver sequence on
October 5. The Project also reviewed and approved the Final sequence
and command generation product for the VE-9 sequence on October 9.
This sequence controls the spacecraft activities from October 22 to
December 7 and includes the PLS (Plasma) instrument shade retraction,
Probe checkout, and the playback of Venus data activities.
The Preliminary GDS (Ground Data System) Test Plan for Earth 1
support was distributed for final review. End-to-end GDS testing is
scheduled to start on October 26th in conjunction with Mission
Readiness Tests (MRT) by the DSN. Galileo MRTs with the 34 meter HEF
(High Effiecency) antennas have been successfully completed at
Goldstone and Spain. Normal ranging operations using 3db suppression
rather than 9 db are now possible due to the improved signal levels.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.185 | GALILEO Update - October 16 | ADVAX::KLAES | All the Universe, or nothing! | Wed Oct 17 1990 14:43 | 27 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/16/90
Date: 16 Oct 90 18:55:40 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Mission Status
October 16, 1990
The Galileo spacecraft's performance continues to be excellent.
Today, via the spacecraft's stored sequence, the telemetry data rate
was automatically increased from 40 bps to 1200 bps. This was the
first opportunity based on link predictions to operate at 1200 bps
since post-Venus flyby. However, ground data lock-up was unsuccessful
due to use of the 34-meter station in Australia. Station coverage was
recently altered to provide 70-meter coverage for Ulysses. However,
several minutes later, as planned, the spacecraft was configured back
to 40 bps with successful data lockup.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.186 | GALILEO Update - October 17 | ADVAX::KLAES | All the Universe, or nothing! | Thu Oct 18 1990 17:10 | 71 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/17/90
Date: 17 Oct 90 18:25:29 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Mission Status
October 17, 1990
The Galileo spacecraft's performance continues to be excellent.
Today, the spacecraft's 1200 bps high rate engineering telemetry data
was successfully received and processed using both 70 meter antennas
in Goldstone and Australia. This is the first time since the Venus
flyby on February 9 that link performance permitted 1200 bps telemetry
data to be transmitted and processed. Yesterday, several commands were
sent to configure the spacecraft's telecommunications hardware in
support of the planned delta DOR (Differential One-way Ranging)
navigation activity. The delta DOR was successfully completed today.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 10/17/90
Date: 17 Oct 90 23:28:45 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
October 17, 1990
One year after its successful launch by STS-34 Atlantis and an
IUS rocket, the Galileo spacecraft is "only" 27.9 million miles from
Earth, although it has traveled more than 569 million miles around the
Sun and past Venus in the last year to reach this point. Its present
speed in solar orbit is 54,112 mph; round-trip communication time is
five minutes.
The spacecraft executed its sixth trajectory-correction maneuver
last Tuesday (October 9), achieving a velocity change of 0.51 meter
per second (about 1.1 mph) and moving the December 8 Earth
closest-approach point to about 2,000 miles above the surface.
Another maneuver in November will adjust the altitude to the final
desired value of about 600 miles; one more maneuver is planned, if
needed, to remove any small residual error.
Spacecraft health and performance during and since last week's
maneuver are excellent. The decreasing distance from Earth has
permitted the telemetry rate to be stepped up this week from 40 to
1200 bits per second, for the first time since last February.
The current operating sequence, which has been controlling
routine spacecraft activities since June, is nearing completion. The
next sequence, covering spacecraft activities through December 7, will
be sent up to Galileo today. It includes the next two scheduled
maneuvers, Venus data playback, preparation for and the start of Earth
science data acquisition, and checkout of the atmospheric probe.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.187 | GALILEO Update - October 18 | ADVAX::KLAES | All the Universe, or nothing! | Fri Oct 19 1990 17:09 | 33 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/18/90
Date: 18 Oct 90 22:58:45 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Status Report
October 18, 1990
Today marks the one year anniversary of the Galileo deployment
from the Space Shuttle. Today at the beginning of the DSN (Deep Space
Network) track, CDS (Command Data Subsystem) telemetry showed a
recurrence of the despun Critical Controller A POR (Power On Reset)
telemetry indication. This same telemetry signature has been observed
several times in the past and was reset successfully by ground
command. The observed indication may be the result of a faulty
telemetry indicator circuit. There is no loss in CDS functionality as
a consequence of this event and the spacecraft continues to perform
normally. Ground controllers will send the same commands as before to
reset the telemetry indication.
Part I of the VE-9 (Venus-Earth) sequence memory load which
controls spacecraft activities from October 22 to December 7 will be
transmitted to the spacecraft today.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.188 | GALILEO Update - October 19 | ADVAX::KLAES | All the Universe, or nothing! | Fri Oct 19 1990 22:17 | 106 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/19/90
Date: 19 Oct 90 18:34:42 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
October 19, 1990
Yesterday was the first anniversary of the Galileo launch from
STS-34. Spacecraft performance and health are excellent; plans for the
Earth flyby activities on December 8 are proceeding well.
As of noon (PDT) Thursday, October 18, 1990, the Galileo
spacecraft is 27,913,650 miles from Earth and traveling at a
heliocentric speed of 54,110 miles per hour; distance to the Sun is
111,233,990 miles (1.21 AU). Round trip light time is 5 minutes, 4
seconds.
A NO-OP command was sent on October 15 to reset the Command Loss
Timer to 264 hours, the planned value for this mission phase.
A series of Delayed Action Commands (DACs) were sent to the
spacecraft on October 16. The first DAC reconfigured the downlink
telemetry data rate from 1200 bps, which was automatically selected by
the stored sequence, to 40 bps (uncoded) to enable positive
verification of subsequent DACs. The data rate change was
necessitated by a recent DSN (Deep Space Network) coverage change
which provided the 70-meter station to Ulysses for its TCM (Trajectory
Correction Maneuver) resulting in Galileo using the 34-meter station
in Australia.
As a further consequence of Ulysses related coverage changes, the
planned delta DOR (Differential One-way Ranging) on October 16 was
moved to October 17 requiring DACs to reconfigure the radio frequency
subsystem and the Telemetry Modulation Unit for the delta DOR activity
and then reconfiguring the hardware back to normal operating state.
The last DACs sent on October 16 involved powering off the NIMS
(Near Infrared Mapping Spectrometer) electrical heater to preclude a
possible thermal violation of the SSI (Solid State Imaging) detector
limit resulting from positioning the scan platform at large cone
angles (above 165 degrees). The high cone angle positions were
required to support UVS (Ultraviolet Spectrometer) Lyman Alpha data
collection on October 18. Subsequent to the Lyman-Alpha activity, the
NIMS heater was reactivated. Since the heater was powered off for a
short time (about 3 hours) there was minimal effect to the thermal
control of the RPM (Retro Propulsion Module).
The EUV (Extreme Ultraviolet Spectromter), DDS (Dust Detector)
and MAG (Magnetometer) Cruise Memory Readouts (MROs) planned for
October 16 were commanded via the stored sequence but about a 95
percent of the data was lost due to Australia 70 meter coverage
provided to Ulysses; however, the cruise science MROs on October 18
were successfully performed and collected.
A Command Detector Unit (CDU) Signal-to-Ratio (SNR) test was
successfully completed on October 16. This periodic test provides
continuing trend information characterizing the telecommunications
hardware used for uplink commanding.
Another delta DOR activity was successfully completed on October
17. This activity again was a North/South pass using the 70 meter
antennas in Australia and Goldstone. This was the seventh of 27
planned delta DOR activities prior to Earth closest approach. Delta
DOR is an additional navigation data source in addition to doppler and
ranging data.
The VE-9 (Venus-Earth-9) Part I memory sequence load was
successfully transmitted and received by the spacecraft on October 18.
This sequence controls spacecraft activities from October 22 to
December 7 and includes time windows for TCM-7, TCM-8, TCM-8A, the PLS
(Plasma Instrument) shade retraction, Probe Checkout, and the playback
of Venus data activities. Part II of the VE-9 sequence memory load was
successfully transmitted and received by the spacecraft today. The
entire VE-9 sequence memory load is now on-board Galileo and will
become active on October 22.
UVS Lyman Alpha data collection continued as planned on October
18. This data is stored on the spacecraft tape recorder for playback
along with Venus Encounter data planned for November 19-21.
The AC/DC bus imbalance measurements exhibited some minor
activity. The AC measurement fluctuated 1 to 2 DN during a period of
no spacecraft activity and is stable near 48.6 volts. The DC
measurement dropped about 10DN and is stable near 18.8 volts. All
other power-related and subsystem telemetry measurements are normal.
Sometime between the end of the DSN track on October 17 and the
start of track on October 18, the ninth despun CDS (Command Data
Subsystem) Critical Controller 2A POR (Power on Reset) telemetry
indication was observed. The signature was the same as that observed
in the previous eight occurrences. Actions to reset the telemetry
indication were completed later on October 18. All actions were
successfully completed and a NO-OP command was sent to reset the
Command Loss Timer to 216 hours, the planned value for this mission
phase.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.189 | GALILEO Update - October 22 | ADVAX::KLAES | All the Universe, or nothing! | Mon Oct 22 1990 19:53 | 31 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/22/90
Date: 22 Oct 90 19:01:12 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Status Report
October 22, 1990
Two delta DOR (Differential One-way Ranging) navigation
activities were successfully performed on Sunday, October 21, 1990.
The delta DORs consisted of a North/South and East/West pass using the
70 meter antenna pair in Goldstone/Australia and Goldstone/Spain.
Another delta DOR navigation activity was completed today. Data
analysis is in process.
The DC bus imbalance telemetry measurement dropped about 6 volts
suggesting a different bus balance condition. The drop occurred
during a period with no spacecraft electrical load switching or
unusual mechanical motion. All other power-related measurements and
spacecraft telemetry are normal. This telemetry measurement has
exhibited erratic behavior since December 4, 1989.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.190 | GALILEO Update - October 23 | ADVAX::KLAES | All the Universe, or nothing! | Thu Oct 25 1990 13:48 | 26 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.astro
Subject: Galileo Update - 10/24/90
Date: 24 Oct 90 17:46:50 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Status Report
October 24, 1990
The health of the Galileo spacecraft continues to be excellent.
On October 22, a command was sent to reset the Command Loss Timer to
216 hours, the planned value of this mission phase. Another East/West
navigation pass delta DOR (Differential One-way Ranging) activity was
successfully completed using the 70 meter Goldstone antenna and 34
meter Madrid antenna. Today an attitude control star scanner
intensity calibration will be performed. This calibration is part of
planned periodic calibrations of the attitude control elements.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.191 | Galileo Update - 10/25/90 | 4347::GRIFFIN | Dave Griffin | Fri Oct 26 1990 12:45 | 70 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Date: 26 Oct 90 00:35:36 GMT
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
October 25, 1990
As of noon (PDT) Thursday, October 25, 1990, the Galileo spacecraft is
23,571,050 miles from the Earth and traveling at a heliocentric speed of
55,370 miles per hour; distance to the Sun is 109,203,570 miles (1.13 AU).
Round trip light time is 4 minutes, 19 seconds.
Periodic radio receiver automatic gain control and tracking loop
capacitor tests were performed on October 19. These tests provide continuing
trend data to characterize the receiver performance.
The VE-9 (Venus-Earth-9) sequence stored on-board the spacecraft went
active as planned on October 22.
A NO-OP command was sent on October 22 to reset the Command Loss Timer to
216 hours, the planned value for this mission phase.
Six delta DOR (Differential One-way Ranging) navigation activities were
performed this week. All were successful except for a single North/South pass
using the 70 meter antennas in Goldstone and Australia on October 22. This
delta DOR was lost due to a hardware failure in Australia. The delta
activities on October 21 and 25 included both North/South and East/West passes
using different combination of antennas from Goldstone/Spain/Australia. A
total of 13 of the planned 27 delta DOR activities are complete; 10 were
successful.
A cruise science memory readout was successfully performed for the MAG
(Magnetometer) instrument on October 22.
Commands were sent on October 24 to update the star scanner threshold
level in preparation for the planned star scanner intensity calibration later
that day. The current threshold setting would allow collecting unwanted
intensity data from several dimmer stars and Jupiter. This updated threshold
level guarantees collecting data from the intended stars. In addition to
this calibration, other AACS (Attitude and Articulation Control Subsystem)
calibration data was collected for gyro drift, SBA (Spin Bearing Assembly) drag
torque and wobble; all data was collected successfully.
The AC bus imbalance measurement exhibited minor activity fluctuating
1-2 DN and is stable near 48.4 volts. The DC measurement by contrast dropped
60 DN from 17.5 volts down to 10.5 volts and then gradually increased to 12
volts. The 60 DN drop occurred during a period of no spacecraft activity. All
other power-related and subsystem telemetry measurements are normal.
The INS electronics was powered on and the Bay C/D heaters were turned
off on October 24. The INS electronics will normally remained powered (gyro
rotors off but activated for required inertial mode operation) to further
reduce the temperature excursions of Bay A CDS (Command Data Subsystem)
electronics.
The first combined GDS/MRT (Ground Data Systems/Mission Readiness Test)
for Earth 1 was successfully completed Tuesday, October 24, with the Goldstone
Signal Processing Center. Real time command and telemetry functions required
for Earth 1 support were demonstrated. In addition magnetic tapes were
generated and provided to MIPL (Multimission Image Processing Lab) and DRS
(Data Records Subsystem) for interface validation.
The Galileo Gravity Wave tests at the Goldstone 34 meter station were
completed on October 18 and 19.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.192 | Galileo Update - 10/26/90 | 4347::GRIFFIN | Dave Griffin | Mon Oct 29 1990 13:03 | 26 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Date: 26 Oct 90 21:37:15 GMT
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
October 26, 1990
The Galileo spacecraft is just under 23 million miles from
Earth, approaching us from beyond Earth's orbit at a speed of
more than 25,000 mph. Speed in solar orbit is 55,565 mph, and
round-trip communication time is down to 4 minutes 7 seconds.
Spacecraft health and mission performance continue to be
excellent and close to predictions. The engineering telemetry
rate is 1200 bits per second. Spacecraft events are now under
the control of a new operational sequence, which took effect
Monday and will continue through December 7, the day before the
first Earth gravity assist. This sequence continues the
relatively quiet level of activity seen over the past few months,
but with a gradually increasing amount of science activity.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.193 | GALILEO Update - November 1 | ADVAX::KLAES | All the Universe, or nothing! | Fri Nov 02 1990 19:38 | 43 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/01/90
Date: 1 Nov 90 19:09:51 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
November 1, 1990
The Galileo spacecraft is now 19.4 million miles from Earth, and
more than 107 million miles from the Sun. Its speed in orbit around
the Sun is 56,580 mph, and the round-trip communication time to Earth
is just under 3 1/2 minutes.
Spacecraft health and mission performance continue to be
excellent. Last Friday, October 26, the spacecraft performed a
scheduled turn to keep its delicate equipment shaded from solar
heating; today it conducts a scheduled propulsion subsystem
maintenance activity to clean out the propellant plumbing. Also today
the protective sunshade is being retracted from the plasma instrument
in preparation for its Earth observations.
Tuesday and Wednesday the Orbiter Engineering Team completed a
real-time simulation of parts of the Earth encounter sequence on the
Galileo test bed. This test system includes breadboard or
flight-hardware versions of the command and data subsystem, attitude
and articulation control, data storage, imaging electronics, and parts
of the power distribution and cabling, as well as ground support
equipment. Because of time limitations, only certain key activities
such as Sun occultation, antenna transfer, and selected science
observations were actually run. Data from the simulation were
received, stored, and analyzed in the same manner as flight data.
Earlier, the Sequence Team tested other parts of the sequence on their
simulator, which includes a version of the command and data subsystem.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.194 | GALILEO Update - November 6 | ADVAX::KLAES | All the Universe, or nothing! | Wed Nov 07 1990 14:49 | 23 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/06/90
Date: 6 Nov 90 20:31:12 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Galileo Status Report
November 6, 1990
A NO-OP command was sent yesterday to the Galileo spacecraft to
reset the Command Loss Timer to 216 hours. A MAG (Magnetometer)
instrument science memory readout was also successfully completed.
Today, two delta DOR (Differential One-way Ranging) navigation
activities were completed successfully.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.195 | GALILEO Update - November 9 | ADVAX::KLAES | All the Universe, or nothing! | Mon Nov 12 1990 19:39 | 99 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/09/90
Date: 9 Nov 90 23:24:37 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 9, 1990
As of noon (PST) Thursday, November 8, 1990, the Galileo
spacecraft is 15,401,300 miles from Earth and traveling at a
heliocentric speed of 58,380 miles per hour; distance to the Sun is
104,470,860 miles (1.11 AU). The spacecraft is spinning at 2.89 rpm
with a spacecraft attitude sun point angle of 4.9 degrees. Round trip
light time is 2 minutes, 50 seconds.
A special NO-OP command was successfully sent on November 2 using
the 26-meter antenna in Spain to demonstrate command capability in the
event contingency backup 26-meter commanding is required during the
Earth Flyby. Another NO-OP command was sent on November 5, as planned,
to reset the Command Loss Timer to 216 hours, the planned value for
this mission phase.
A MAG (Magnetometer) instrument cruise science Memory Readout
(MRO) was successfully performed on November 5; a planned EUV (Extreme
Ultraviolet Spectrometer) MRO on November 8 was lost.
Commands were sent on November 5 to enable the thruster firing
all clear algorithm allowing the PPR (Photopolarimiter Radiometer) and
PLS (Plasma) instruments to be in a state to collect data when powered
on later in the sequence, i.e., PPR covers open and PLS high voltages on.
Commands were also sent on November 5 to load a series of
Delayed-Action Commands (DACs) scheduled for execution on November 7
and November 13. The commands will be used to cycle the RCT/NIMS
(Near Infrared Mapping Spectrometer) heaters off/on and RTG Boom
Heaters on/off. Powering off the RCT/NIMS is required to preclude
possible radiative induced overheating of the SSI (Solid State
Imaging) detector during scan platform high cone slews associated with
UVS (Ultraviolet Spectrometer) data collection. Turning on the RTG
Boom heaters is required to minimize heat flow into the RPM (Retro
Propulsion Module) tanks. Proper command execution was verified for
the November 7 set of DACs.
Two more delta DOR (Differential One-way Ranging) activities were
completed on November 6. Both delta DORs were successful. The 70
meter Goldstone/Australia pass was the first activity where link
performance allowed simultaneous transmission of spacecraft telemetry
data along with DOR tone modulation. A total of 19 of the planned 27
delta DOR activities are complete; 15 were successful.
The PWS (Plasma Wave), PLS and EPD (Energetic Particles Detector)
instruments were powered-on November 8. Telemetry received shortly
after PLS and EPD power turn on differed from predicted levels.
Status of both instruments has been assessed by the Principal
Investigators and is not considered to be a concern.
The PLS temperatures were observed to exceed predicted levels.
Consequently, non-interactive commands were sent to improve ground
visibility into the state of PLS detectors. Subsequent data analysis
indicated no concern for the PLS. The PLS temperatures are on a
downward trend approaching predicted steady state levels. One of the
EPD LEMMS detectors exhibited higher than expected noise counts at its
lowest threshold setting. A non-interactive command was sent to
increase the threshold setting to collect important detector status
information. The cause of the increased noise counts is under
investigation. Preliminary results indicate no concern for the health
of the detector.
For some selected periods the spacecraft's telemetry downlink
data rate was commanded to 7.68 kbps via the stored sequence. This
was the first time since Venus flyby that this data rate has been used
and successfully processed by the ground data system.
The AC bus imbalance measurement remained relatively stable. The
AC measurement fluctuated about 2DN and is stable near 48.6 volts.
The DC measurement fluctuated about 100 DN (11 volts) during a period
of no spacecraft activity and is near 5 volts. All other
power-related and spacecraft telemetry measurements are normal.
The Project reviewed and approved the final cruise plan sequence
products for VE-12 (Venus-Earth 12) on November 5. This sequence
controls spacecraft events from December 17, 1990 to February 18,
1991. The Project also reviewed and approved the final sequence and
command generation products for the VE-11 Earth encounter sequence;
Earth closest approach is on December 8.
The Project reviewed and approved the TCM-7 (Trajectory Course
Maneuver-7) design. This maneuver will be executed on November 13,
and will use the axial and lateral thrusters.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.196 | GALILEO Update - November 12 | ADVAX::KLAES | All the Universe, or nothing! | Mon Nov 12 1990 20:30 | 26 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/12/90
Date: 12 Nov 90 20:00:10 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 12, 1990
A command was sent today to the Galileo spacecraft to reset the
command loss timer to 216 hours, the planned value for this mission
phase. Another delta DOR (Differential One-way Ranging) navigation
activity was successfully completed today using using the 70 meter
antenna pairs at Goldstone/Spain and Goldstone/Australia. The
sequence memory load for TCM-7 (Trajectory Course Maneuver 7) will be
sent to the spacecraft today. The spacecraft will execute the
maneuver tomorrow using its axial and lateral thrusters.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.197 | GALILEO Update - November 14 | ADVAX::KLAES | All the Universe, or nothing! | Wed Nov 14 1990 18:31 | 29 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/14/90
Date: 14 Nov 90 16:32:50 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 14, 1990
Yesterday, the Galileo spacecraft successfully executed the TCM-7
(Trajectory Course Maneuver 7) with a slight overburn imparting a
delta velocity of about 1.26 m/sec. The thruster burns were completed
in two segments, with the first segment occuring while being tracked
by the Australia 70 meter station, and the second segment with the
Spain 70 meter station.
Today, the PPR (Photopolarimiter Radiometer) science instrument
will be powered on. Tomorrow, two delta DOR (Differential One-way
Ranging) navigation activities are scheduled using the 70 meter
antennas pairs at Goldstone/Australia and Goldstone/Spain.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.198 | GALILEO Update - November 15 | ADVAX::KLAES | All the Universe, or nothing! | Fri Nov 16 1990 16:20 | 24 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/15/90
Date: 16 Nov 90 00:57:33 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 15, 1990
The Galileo spacecraft's health continues to be excellent.
Today, another delta DOR (Differential One-way Ranging) navigation
activity was successfully completed using the 70 meter antenna pairs
in Goldstone/Spain and Goldstone/Australia. Tomorrow the spacecraft
will perform, via the stored sequence, planned thruster maintenance
and Sun point maneuver activities.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.199 | GALILEO Update - November 16 | ADVAX::KLAES | All the Universe, or nothing! | Fri Nov 16 1990 18:12 | 33 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/16/90
Date: 16 Nov 90 16:50:18 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 16, 1990
The Galileo spacecraft is now 11.6 million miles from Earth and
approaching us at a closing speed of more than 22,000 miles per hour.
The spacecraft's heliocentric speed is 60,140 mph. The analysis of
the trajectory correction maneuver, performed last Tuesday, shows all
aspects of the maneuver were very close to predictions. Another
maneuver is planned for Friday, November 28. Closest approach to Earth
on this first Earth Gravity Assist flyby will be at 12:35 pm PST,
Saturday, Dec. 8. At that time, Galileo will fly 590 miles above the
northwest Atlantic. Spacecraft health and mission performance
continue to be excellent.
Next week from November 19-21, Galileo will play back the Venus
data recorded during the flyby last February. A press conference to
discuss these and other aspects of the mission is set for Thursday,
November 29, at 9:00 am PST. It will be on NASA Select TV.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.200 | Time conversion request | 42653::HAZEL | Author of Public Domain notes | Sat Nov 17 1990 10:26 | 4 |
| How many hours difference is there between PST (Pacific Standard Time?)
and GMT, for those of us over in Europe?
Dave Hazel
|
| 560.201 | 8 hours behind | JANUS::BARKER | Jeremy Barker - T&N/CBN Diag. Eng. - Reading, UK | Mon Nov 19 1990 10:45 | 6 |
| > How many hours difference is there between PST (Pacific Standard Time?)
> and GMT, for those of us over in Europe?
8 hours behind GMT
jb
|
| 560.202 | GALILEO Update - November 16 | ADVAX::KLAES | All the Universe, or nothing! | Mon Nov 19 1990 16:56 | 111 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 11/16/90
Date: 16 Nov 90 21:55:14 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 16, 1990
As of noon (PST) Thursday, November 15, 1990, the Galileo
spacecraft is 11,584,870 miles from Earth and traveling at a
heliocentric speed of 60,140 miles per hour; distance to the Sun is
101,784,750 miles (1.09 AU). Round trip light time is 2 minutes, 8
seconds.
The sequence commanded flushing maneuver is in process as
planned. This is the 21st flushing maneuver executed since launch.
Later today the spacecraft will execute a Sun pointing maneuver of
approximately 12.5 degrees.
A non-interactive command was sent on November 9 to reset the EPD
(Energetic Particles Detector) LEMMS detector threshold to its normal
low setting. The previous day, the threshold was increased in
response to high noise counts. Subsequent monitoring of the detector
performance indicated proper operation and allowed a safe return to
the lower threshold setting.
A special EUV (Extreme Ultraviolet Spectrometer) memory readout
was performed on November 10 in response to anomalous operation
observed after commanding the instrument to the encounter mode. The
MRO (Memory Read Out) revealed two bits of a single byte were
corrupted. The memory corruption is similar to that observed during
last December's 4-day science checkout although at a different memory
location. The latest anomaly was recreated and verified on the EUV
simulator at the University of Colorado. The cause of this EUV
anomaly and the previous December anomaly is being investigated
vigorously. Commands were sent on November 13 to "patch" the
corrupted memory location and reset it to its proper state compatible
with Earth encounter data collection and proper instrument operation
was restored.
A NO-OP command was sent on November 12 to reset the Command Loss
Timer to 216 hours, the planned value for this mission phase.
The TCM-7 (Trajectory Course Maneuver) sequence memory load was
successfully transmitted to the spacecraft on November 12. The
spacecraft properly executed the maneuver on November 13. The
maneuver was comprised of one axial segment and one lateral segment.
Spacecraft performance throughout the maneuver activity was excellent.
The RPM (Retro Propulsion Module) tank pressure and thruster
temperatures were near predicted levels; temperatures were similar to
those observed in TCM-6. No spin rate correction was required between
the axial and lateral burn segments or at the end of the maneuver
activity. Attitude pointing perturbation was minimal beginning at
about 5 mrad and growing to almost 8 mrad after the axial segment.
This pointing error was corrected with a sequence planned pointing
correction to near 0.5 mrad. The lateral burn segment produced about
0.8 mrad of attitude pointing perturbation, well below the 2 mrad
threshold, and consequently the sequence planned pointing correction
was not performed. Preliminary radio frequency navigation data
indicates an axial and lateral overburn of about one percent which is
near pre-maneuver execution predictions.
Four delta DOR (Differential One-way Ranging) navigation
activities were completed this week - two on November 12 and two on
November 15. The delta DOR activities were successful. A total of 23
of the planned 27 delta DOR activities are complete; 19 were successful.
The PPR (Photopolarimiter Radiometer) instrument was powered on
November 14. Instrument operation is normal; power and thermal
profiles are within predicted levels. The PPR calibration scheduled
for this morning was completed as planned. There were no unexpected
events; data is being analyzed.
The AC bus imbalance measurement dropped about 2 DN (.4 volt) and
is stable near 48.2 volts. DC bus measurement is presently reading
about 2 volts. Both AC and DC changes occurred during periods of no
spacecraft load switching. Very little (1-2 DN) AC/DC bus measurement
change was observed during the TCM-7 execution. All other
power-related and spacecraft telemetry measurements are normal.
The final Project GDS (Ground Data Systems) test for Earth 1 was
successfully completed with the Canberra 34 meter and 26 meter
stations on November 13. A key objective was met with the successful
test of the probe data flow from the tracking station to the Probe
Flight Operations Equipment (PFOE) in the Galileo Mission Support Area
(MSA). This link is required to support the Probe checkout scheduled
for December 4th. GDS testing has now validated all GDS functions
required for Earth 1 support.
The DSN (Deep Space Network) and Project Flight Team personnel
participated in a "walk-through" rehearsal of the Earth Closest
Approach (ECA) operations on November 15th. During the review several
minor changes to the sequence of events were suggested and accepted by
the Flight Control and Support Office. This walk-through will be
repeated next week.
The LGA-2 (Low Gain Antenna-2) retraction and HGA (High Gain
Antenna) deployment reviews were held on November 14 and 15,
respectively. No concerns/discrepancies were identified by the review
board between expected flight conditions and ground test data.
Expected flight conditions are well within the ground test database.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.203 | GALILEO Update - November 19 | ADVAX::KLAES | All the Universe, or nothing! | Tue Nov 20 1990 17:12 | 26 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/19/90
Date: 19 Nov 90 19:24:10 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 19, 1990
The health of the Galileo spacecraft continues to be excellent.
Today, another delta DOR (Differential One-way Ranging) navigation
activity was successfully completed using the 70 meter antenna pairs
at Goldstone/Spain and Goldstone/Australia. Playback of Venus science
data is presently in process. Today, recorded data on tracks 1 and 2
will be returned at 28.8 Kbps. The remainder of the data playback
activity will be performed on November 20 and 21. Tomorrow, a No-Op
command will be sent to reset the command Loss Timer.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.204 | GALILEO Update - November 20 | ADVAX::KLAES | All the Universe, or nothing! | Wed Nov 21 1990 19:26 | 25 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/20/90
Date: 20 Nov 90 21:45:11 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 20, 1990
Yesterday, Venus data on tracks 1 and 2 of the Galileo
spacecraft's tape recorder was successfully returned via stored
sequence controlled playback. Today, Venus data on tracks 1 and 3 will
be playedback; data playback is presently in process. Tomorrow, the
final playback of Venus data on tracks 2 and 3 is scheduled. The NIMS
(Near Infrared Mapping Spectrometer) instrument will be powered on
tomorrow via stored sequence control.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.205 | Galileo Update - 11/21/90 | 4347::GRIFFIN | Dave Griffin | Fri Nov 23 1990 22:53 | 19 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Date: 21 Nov 90 21:36:58 GMT
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 21, 1990
The health of the Galileo spacecraft continues to be excellent.
Yesterday, Venus data on tape recorder tracks 3 and 1 was successfully
returned. Today, the final Venus data playback will occur; track 2 data
playback is in process. Also today, the NIMS (Near Infrared Mapping
Spectrometer) instrument was powered on. Preliminary data
indicates NIMS operation is normal.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.206 | GALILEO Update - November 22 | ADVAX::KLAES | All the Universe, or nothing! | Mon Nov 26 1990 20:13 | 98 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/22/90
Date: 26 Nov 90 16:58:03 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 22, 1990
As of noon (PST) Wednesday, November 21, 1990, the Galileo
spacecraft is 8,456,170 miles from Earth and traveling at a
heliocentric speed of 61,788 miles per hour; distance to the Sun is
99,324,410 miles (1.07 AU). The spacecraft is spinning at 3.15 rpm;
downlink telemetry is at 7680 bps through the Low Gain Antenna. Round
trip light time is 1 minute, 28 seconds.
A SITURN to lead the Sun was successfully performed on November
16. The turn, about 22 degrees, was the largest to date and resulted
in the spacecraft leading the sun by about 12.5 degrees. Spacecraft
performance during the activity was normal and without incident.
The 21st RPM (Retro Propulsion Module) flushing activity was
successfully performed on November 16. All thrusters were flushed
during this activity except for the P-thrusters which were used later
for the Sun point activity. Successful flushing was directly confirmed
and observed via high rate engineering data at 1200 bps (bits/second).
Delayed Action Commands (DACs) were sent on November 16 to turn
off the S-Band ranging channel to improve the RF downlink performance for
subsequent Venus science data playback on for November 19, 20, and 21.
A NO-OP command was sent on November 20 to reset the Command Loss
Timer to 240 hours, the planned value for this mission phase.
The PPR (Photopolarimiter Radiometer) instrument continued its
calibration and checkout activities. Preliminary data indicates the
instrument is working well.
The Venus science data was played back from the spacecraft on
November 19, 20, and 21. The data has been stored on the spacecraft
since early February along with UVS (Ultraviolet Spectrometer)
Lyman-Alpha data collected during cruise. The data was played back
twice from Data Memory Subsystem (DMS) tape recorder. Data was
returned from tracks 1 and 2 on November 19, then tracks 3 and 1 on
November 20, and finally tracks 2 and 3 on November 21. Preliminary
results indicate all Venus data was successfully returned and is
presently being processed.
Two delta DOR (Differential One-way Ranging) navigation
activities were completed on November 19. The activities were
successful using the 70 meter antenna pairs at Goldstone/Spain and
Goldstone/Australia. A total of 25 of the planned 27 delta DOR
activities are complete; 21 were successful.
The NIMS (Near Infrared Mapping Spectrometer) instrument was
powered on November 21. Several spacecraft heaters were configured to
maintain acceptable power/thermal margins. Preliminary data indicates
the NIMS instrument is functioning normally.
The PCT (Photometric Calibration Target) heaters were powered off
and the RCT-NIMS heater was powered on November 22 for power margin
management and thermal control.
Two non-interactive DACs were sent on November 21 to configure
the PWS (Plasma Wave) instrument to gather calibration data from the
magnetic field sensor; the commands went active later that day. The
first command causes the PWS to inject a square wave signal tone into
its magnetic field circuitry; the second command reconfigured the PWS
back to the normal mode. The calibration was performed to verify
instrument operation in presence of a known fixed source. Review of
Venus data and recent (last week) data indicates the possibility of
spacecraft generated time variable electric and magnetic fields.
Commands were sent on November 21 to turn off the PLS (Plasma)
instrument high voltage. This action drops the instrument power
dissipation by about 1.2 watts and relaxes somewhat thermal concerns
expressed by the Principal Investigator.
The AC bus imbalance measurements dropped about 3 DN and about
47.5 volts. This measurement has been relatively stable since its
inception and is likely indicative of a leakage resistance to chassis
of about 100-500 ohms. During the past 2-3 weeks the DC measurement
has gradually dropped from near 18.5 volts to its present value of
about 2 volts. The gradual decline has not correlated with any
spacecraft load switching event, thermal environment change or
mechanical activity. The present reading can be indicative of a
return leakage path to chassis of about 150 ohms. Tests to better
characterize the PPS telemetry sensor performance are in process. All
other power-related and spacecraft telemetry measurements are normal.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.207 | GALILEO Update - November 26 | ADVAX::KLAES | All the Universe, or nothing! | Tue Nov 27 1990 15:31 | 57 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/26/90
Date: 27 Nov 90 15:55:02 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 26, 1990
The Galileo spacecraft is now 12 days from its first Earth
encounter on December 8. The spacecraft's Command Loss Timer was set
to 96 hours, the planned value for this mission phase. The NIMS (Near
Infrared Mapping Spectrometer) instrument which was successfully
powered on last November 21 will continue its planned calibration
activities. The SSI (Solid State Imaging) instrument will be turned
on later today.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo News Conference
Date: 26 Nov 90 23:16:04 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO NEWS CONFERENCE
A news conference is scheduled at the Jet Propulsion Laboratory,
Pasadena, Calif., on Thursday, November 29 at 1:00 p.m. EST to discuss
recently returned data from the Galileo spacecraft's Venus flyby last
February. Present spacecraft and mission status will be described and
plans for the Earth gravity-assist flyby on December 8 and associated
scientific observations will be outlined.
Participants include Project Manager William J. O'Neil, Project
Scientist Torrance V. Johnson and key members of the Galileo science
team.
The conference will be aired on NASA Select television, Satcom
F2R, Transponder 13, 72 degrees West longitude, with two-way question
and answer capability.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.208 | GALILEO Update - November 27 | ADVAX::KLAES | All the Universe, or nothing! | Tue Nov 27 1990 22:09 | 25 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/27/90
Date: 27 Nov 90 19:58:10 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 27, 1990
Yesterday, the SSI (Solid State Imaging) instrument was
powered-on on the Galileo spacecraft and preliminary data indicates
SSI operation is normal. Today, the NIMS (Near Infrared Mapping
Spectrometer) and the SSI instrument will continue their planned
calibration activities. Tomorrow, TCM-8 (Trajectory Correction
Maneuver 8), the final Pre-Earth encounter trajectory correction
maneuver, will be performed using the L and P thrusters.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.209 | GALILEO Update - November 28 | ADVAX::KLAES | All the Universe, or nothing! | Wed Nov 28 1990 21:48 | 27 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/28/90
Date: 28 Nov 90 19:56:54 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 28, 1990
The health of the Galileo spacecraft continues to be excellent.
The TCM-8 (Trajectory Correction Maneuver 8) sequence memory load was
successfully completed; the maneuver sequence is presently in process.
Yesterday, the spacecraft successfully completed the planned SSI
(Solid State Imaging) and NIMS (Near Infrared Mapping Spectrometer)
photometric calibration activities. Later today, following TCM-8
execution, the spacecraft will perform a schedule turn to lead the
Sun. The Venus images taken by Galileo last February and played back
last week, are presently being displayed on the TV monitors at JPL.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.210 | GALILEO Update - November 29 | ADVAX::KLAES | All the Universe, or nothing! | Thu Nov 29 1990 19:33 | 25 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/29/90
Date: 29 Nov 90 18:11:58 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 29, 1990
Yesterday, the Galileo spacecraft successfully completed the
TCM-8 (Trajectory Correction Maneuver 8), imparting the required
delta velocity just over 5 cm/sec. Also yesterday, subsequent to the
maneuver, the spacecraft completed a 6 degree turn to lead the Sun by
9 degrees. Today, selected remote sensing science will perform
continued planned calibration activities including boresight and star
calibrations.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.211 | GALILEO Fact Sheet - November 29 | ADVAX::KLAES | All the Universe, or nothing! | Thu Nov 29 1990 19:33 | 669 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Fact Sheet
Date: 29 Nov 90 17:57:45 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO FACT SHEET/PROJECT BACKGROUND
November 29, 1990
SUMMARY
Galileo is a NASA spacecraft mission to Jupiter, launched
October 18, 1989, and designed to study the planet's atmosphere,
satellites and surrounding magnetosphere. It was named for the
Italian Renaissance scientist who discovered Jupiter's major
moons in 1610 with the first astronomical telescope.
This mission will be the first to make direct measurements
from an instrumented probe within Jupiter's atmosphere, and the
first to conduct long-term observations of the planet and its
magnetosphere and satellites from orbit around Jupiter. It will
be the first orbiter and atmospheric probe for any of the outer
planets.
The Jet Propulsion Laboratory designed and
developed the Galileo Jupiter orbiter spacecraft and is
operating the mission; NASA's Ames Research Center developed
the atmospheric probe with Hughes Aircraft Company as prime
contractor. The German government is a partner in the
mission through its provision of the spacecraft propulsion
subsystem, scientific instruments on both orbiter and probe,
and ground operations support.
In order to reach Jupiter, Galileo must pick up the
necessary speed by flying past Venus and twice by the Earth,
using the gravity-assist technique employed by Voyager to
reach the planets Saturn, Uranus and Neptune.
These gravity-assist encounters have provided the
opportunity for Galileo to conduct brief scientific
observations of Venus (closest approach February 10, 1990)
and the Earth-Moon system (December 8, 1990 and 1992).
Designed to measure and observe Jupiter's atmosphere,
magnetosphere and satellites, Galileo's instruments can add
to knowledge of the inner bodies, supplementing previous
spacecraft data and complementing the Venus surface studies
by the Magellan project.
In addition, Galileo's flight through the asteroid
belt provides opportunities for the first close-up
observation of an asteroid. In late October 1991 it will
encounter the asteroid Gaspra, and a second potential
opportunity occurs in August 1993, with the asteroid Ida.
In December 1995 the Galileo atmospheric probe will conduct
a direct examination of Jupiter's atmosphere, while the larger
part of the craft, the orbiter, begins a 22-month, 10-orbit tour
of the major satellites and the magnetosphere, including long-
term observations of Jupiter throughout this phase.
The 2-1/2-ton (2,222-kilogram) Galileo orbiter
spacecraft carries 10 scientific instruments; there are
another six on the 750-pound (340-kilogram) probe. The
spacecraft radio link to Earth and the probe-to-orbiter radio
link serve as instruments for additional scientific
investigations.
Galileo communicates with its controllers and
scientists through the Deep Space Network, using tracking
stations in California, Spain and Australia.
LAUNCH OPERATIONS
The Galileo spacecraft was carried into Earth
orbit on October 18, 1989, by Space Shuttle Atlantis,
commanded by Donald E. Williams and piloted by Michael J.
McCulley. Mission specialists Shannon W. Lucid, Ellen S.
Baker and Franklin R. Chang-Diaz deployed Galileo and its IUS
(Inertial Upper Stage) booster from the shuttle. The two-
stage IUS solid rocket accelerated the spacecraft out of
Earth orbit toward the planet Venus.
The Galileo mission was previously designed for a direct
flight of about 2-1/2 years to Jupiter. Changes in the launch
system after the Challenger accident, including replacement of
the Centaur upper-stage rocket with the IUS, precluded this
direct flight. Trajectory engineers designed a new
interplanetary flight path using gravity assists, once with Venus
and twice with Earth, to build up the speed to reach Jupiter,
taking a total of just over 6 years. This is called the Venus-
Earth-Earth-Gravity-Assist or VEEGA trajectory.
EARTH TO JUPITER
Galileo makes three planetary encounters in the
course of its gravity-assisted flight to Jupiter. These
provide opportunities for scientific observation and
measurement of Venus and the Earth-Moon system. The mission
also has a chance to fly close to one or two asteroids,
bodies which have never before been observed close up, and to
obtain data on other phenomena in interplanetary space.
The instruments designed to observe Jupiter's
atmosphere from afar can also improve our knowledge of the
atmosphere of Venus; sensors designed for the study of
Jupiter's moons can add to information about our own planet
and its satellite.
VENUS
The planet Venus is approximately the size and
density of the Earth, and it has a solid surface beneath a
cloudy atmosphere, but it does not otherwise resemble our
planet. The atmosphere is deep and dense; cloud tops are
some 40 miles above the surface, where the atmospheric
pressure is more than 90 times that on Earth and the
temperature near 900 degrees Fahrenheit.
The clouds are essentially opaque to visible light,
and the surface can be observed only by radar from Earth or
spacecraft or by a spacecraft hardy enough to land and
survive on the surface. Many observations of these types
have been made, but they have been of limited scope or
resolution; NASA's Magellan mission, in orbit around Venus,
is making a global high-resolution radar survey. Many
features of the atmosphere remain unknown, including details
of the motion of the upper regions, the form of deeper
clouds, and the existence of lightning storms.
The Galileo spacecraft approached Venus February 9,
1990 from the night side and passed across the sunlit
hemisphere. Closest approach was about 10 p.m. PST, or
about 1 a.m. EST February 10, at a distance of 10,000 miles
(16,000 kilometers) above the cloudtops. For a day before
and several days after closest approach Galileo scientists
collected measurements of charged particles, dust and
magnetism, infrared and ultraviolet spectral observations,
data for infrared lower-atmosphere maps, and 81 camera
images.
Virtually all these data had to be tape-recorded on
the spacecraft for playback in November 1990, because
Galileo's capabilities are constrained during this early
phase of flight.
The spacecraft was originally designed to operate
between Earth and Jupiter; at Jupiter, sunlight is 25 times
weaker than at Earth and temperatures are much lower. The
VEEGA mission has exposed the spacecraft to a hotter
environment from Earth to Venus and back; spacecraft
engineers devised a set of sunshades to protect the craft.
For this system to work, the top of the spacecraft was
pointed close to the Sun, with the main antenna furled
(precluding high-rate communications) for protection from the
Sun's rays, until well after the first Earth flyby in
December 1990. Therefore, scientists had to wait until the
spacecraft is close to Earth to receive the recorded Venus
data, transmitted through a low-gain antenna.
EARTH (FIRST PASS)
Approaching Earth for the first time about 14
months after launch, the Galileo spacecraft will have the
opportunity to measure the magnetic tail far above the dark
side of Earth and parts of both the near and far sides of
the Moon. After passing Earth, Galileo will observe its
sunlit side. At this short range, scientific data can be
transmitted at higher rates using only the spacecraft's low-
gain antennas. The high-gain antenna is to be unfurled like
an umbrella about 5 months after the first Earth encounter.
FIRST ASTEROID: GASPRA
Nine months after the Earth passage, Galileo will
enter the asteroid belt, and 2 months after that it will
perform the world's first asteroid encounter. Gaspra is
believed to be a fairly representative main-belt asteroid,
about 10 miles or 15 kilometers across, probably similar in
composition to stony meteorites.
The spacecraft will pass about 900 miles (1,600
kilometers) from Gaspra at a relative speed of about 18,000
miles per hour; scientists expect to collect several pictures
of Gaspra, and measurements to indicate composition and
physical properties. The exact flyby geometry has not yet
been selected.
EARTH (SECOND PASS)
Thirteen months after the Gaspra encounter, the
spacecraft will have completed its 2-year elliptical orbit
around the Sun and will arrive back at Earth. It will need a
much larger elliptical orbit (with a 6-year period) to
reach as far as Jupiter, and the second flyby of Earth will
pump the orbit up to that size.
Passing about 185 miles (300 kilometers) above the
surface, 25 miles above the altitude at which it was deployed
from the Space Shuttle more than 3 years before, Galileo
will use Earth's gravity to change its flight direction
and pick up about 8,000 miles per hour.
Each gravity-assist flyby requires several rocket-
thrusting sessions, using Galileo's onboard propulsion
module, to refine the flight path. (Asteroid encounters may
require similar maneuvers to obtain the best observing
conditions.)
Passing the Earth for the last time, the spacecraft's
scientific equipment can make observations of the planet, both
for comparison with Venus and Jupiter and to aid in Earth
studies. It can also observe the north polar regions of our
Moon, for comparison with Jupiter's satellites and to obtain new
data on lunar regions never explored before.
SECOND ASTEROID POSSIBILITY
Nine months later, Galileo could have a second
asteroid-observing opportunity, if this were determined to be
the best use of spacecraft propellant reserves. Ida is about
20 miles or 30 kilometers across; like Gaspra, it is believed
to represent the majority of main-belt asteroids in
composition, though there are believed to be differences
between the two.
Relative velocity for this flyby would be nearly
28,000 miles per hour.
Approaching Jupiter
Some 2-1/2 years after leaving Earth for the third
time and 5 months before reaching Jupiter, Galileo's
probe must separate from the orbiter which has been carrying
it since before launch.
The spacecraft precisely adjusts its trajectory to
establish the atmospheric probe's 5-month free flight to
Jupiter, and then turns to orient the probe so that it will
enter the atmosphere in the correct attitude. Finally, it
spins up to 10 rpm and releases the spin-stabilized probe.
Several days later the Galileo orbiter readjusts its
trajectory to aim for its own Jupiter encounter.
AT JUPITER
Early in December 1995 the Galileo orbiter and
probe will approach Jupiter separately. They will have
travelled about 2-1/2 billion miles (4 billion kilometers) in
a complex multiple looping path for more than 6 years. For
the last 60 days of the approach, the orbiter carries out a
comprehensive program of observations of Jupiter and
measurements of its environment in space.
The probe will enter the atmosphere to make direct
measurements. The orbiter will fly close by Io, receive the
probe signals for relay to Earth and go into orbit around
Jupiter, all in a period of about 7 hours.
While the probe is still approaching Jupiter, the
orbiter will have its first two satellite encounters. After
passing within 20,000 miles (33,000 kilometers) of Europa, it
will fly about 600 miles (1,000 kilometers) above Io's
volcano-torn surface, about 1/20 the closest flyby altitude
of Voyager in 1979.
A few hours later, the probe will enter the upper
atmosphere, about 6 degrees north of Jupiter's equator, at
more than 100,000 miles per hour or about 47 kilometers per
second, and slow by aerodynamic braking for about 2 minutes
before deploying its parachute and dropping its heat shields.
Then it will float down about 125 miles or 200 kilometers
through the clouds, passing from a pressure of 1/10 that on
Earth's surface to about 25 Earth atmospheres in 75 minutes.
The probe batteries are not expected to last beyond this
point, and the radio-communications link will be terminated.
About 133,000 miles (214,000 kilometers) above,
the orbiter will receive, store and transmit the probe's
science data. Next, the orbiter must thrust with its main
engine to go into orbit around Jupiter.
This orbit, the first of 10 planned, will have a
period of about 8 months. Additional maneuvers and the first
Ganymede close flyby in July 1996 will shorten the orbit, and
each time the orbiter returns to the inner zone of satellites
it will make a gravity-assist close pass over one of them to
change its orbit while making close observations. These
satellite encounters will be at altitudes as close as 125
miles (200 kilometers) above the surfaces of the moons,
typically about 100 times closer than the Voyagers' satellite
flybys. Throughout the 22-month orbital phase, Galileo will
continue observing the planet and the satellites and
gathering data on the magnetospheric environment.
SCIENTIFIC ACTIVITIES
Galileo's scientific experiments are being carried out by
more than 100 scientists from six nations. These are supported
by dedicated instruments and the radio subsystems on the Galileo
orbiter and probe. NASA has appointed 13 interdisciplinary
scientists whose studies reach across more than one Galileo
instrument data set. The experiments and principal scientists
are listed at the end of this fact sheet.
SPACECRAFT
The Galileo mission and systems were designed to
investigate three broad aspects of the Jupiter system: the
planet's atmosphere, the satellites and the magnetosphere.
The spacecraft was constructed in three segments, which help
focus on these areas: the atmospheric probe; a non-spinning
section of the orbiter carrying cameras and other remote
sensors; and the spinning main section of the orbiter
spacecraft which includes the fields and particles
instruments, designed to sense and measure the environment
directly as the spacecraft flies through it. The spinning
section also carries the main communications antenna, the
propulsion module, flight computers and most support systems.
Atmospheric Probe
The probe weighs about 750 pounds (340 kilograms),
and includes a deceleration module to slow and protect the
descent module, which carries out the scientific mission.
The deceleration module consists of an aeroshell
and an aft cover, designed to block the heat generated by
slowing from the probe's arrival speed of about 100,000 miles
per hour to subsonic speed in less than 2 minutes.
After the aft cover is released, the descent
module deploys its 8-foot (2.5-meter) parachute and drops the
aeroshell; its radio-relay transmitter and all six of its
instruments go to work (two instruments started storing data
on the way in). Each operating at 128 bits per second, the
dual L-band transmitters send nearly identical streams of
scientific data to the orbiter. Probe electronics are
powered by batteries with an estimated capacity of about 18
amp-hours on arrival at Jupiter.
Probe instruments include an atmospheric structure
instrument group measuring temperature, pressure and
deceleration; a neutral mass spectrometer and a helium-
abundance interferometer supporting atmospheric composition
studies; a nephelometer for cloud location and cloud-particle
observations; a net-flux radiometer measuring the difference,
upward versus downward, in radiant energy flux at each
altitude; and a lightning/radio-emission instrument with an
energetic-particle detector, measuring electromagnetic waves
(light and radio-frequency) associated with lightning and
energetic particles in Jupiter's radiation belts.
Galileo Orbiter
The orbiter, in addition to supporting the probe
activities, will support all the scientific investigations of
Jupiter's satellites and magnetosphere, and remote
observation of the giant planet itself, including those
carried out on the way to Jupiter.
The orbiter weighs about 4,900 pounds (2,222
kilograms), including about 2,035 pounds or 925 kilograms of
rocket propellant. This is used in almost 30 relatively
small maneuvers during the long gravity-assisted flight to
Jupiter, three large thrust maneuvers including the one that
puts the craft into its Jupiter orbit, and the 30 or so trim
maneuvers planned for the satellite tour phase.
The propulsion module consists of 12 10-newton thrusters, a
single 400-newton engine, and the fuel, oxidizer, and
pressurizing-gas tanks, tubing, valves and control equipment. (A
thrust of 10 newtons would support a weight of about 1 kilogram
or 2.2 pounds at Earth's surface.) The propulsion system was
developed and built by Messerschmitt-Bolkow-Blohm (MBB) and
provided by the Federal Republic of Germany as a partner in
Project Galileo.
The orbiter's maximum communications rate is 134
kilobits per second (the equivalent of about one black-and-
white image per minute); there are other data rates, down to
10 bits per second, for transmitting engineering data when
the Earth-spacecraft geometry makes communication difficult.
The Galileo spacecraft acquires and transmits a total of
1,418 engineering measurements (temperatures, voltages,
computer states and counts, and the like). The spacecraft
transmitters operate at S-band and X-band (2,295 and 8,415
megahertz) frequencies.
The high-gain antenna is a 16-foot (4.8-meter)
umbrella-like reflector unfurled after the first Earth
flyby. Two low-gain antennas (one pointed forward and one
aft, both mounted on the spinning section) are provided to
support communications duri9g the Earth-Venus-Earth leg of
the flight and whenever the main antenna is not deployed and
pointed at Earth. The despun section of the orbiter carries
a radio relay antenna for receiving the probe's data
transmissions.
Because the time delay in radio signals from Earth
to Jupiter and back is more than 1 hour, the Galileo
spacecraft was designed to operate from programs sent to it
in advance and stored in spacecraft memory. A single master
sequence program can cover from weeks to months of quiet
operations between planetary and satellite encounters.
During busy encounter operations, one program covers only a
few days or less.
These sequences operate through flight software
installed in spacecraft computers in various subsystems and
scientific instruments. In the command and data subsystem,
there are about 35,000 lines of code, including 7,000 lines
of automatic fault protection software, which operates to put
the spacecraft in a safe state if an untoward event such as
an onboard computer glitch were to occur. The articulation
and attitude control flight software has about 37,000 lines
of code, including 5,500 lines devoted to fault protection.
Electrical power is provided to Galileo's
equipment by two radioisotope thermoelectric generators.
Heat produced by natural radioactive decay of plutonium is
converted to approximately 500 watts of electricity (570
watts at launch, 485 at the end of the mission) to operate
the orbiter equipment for its 8-year baseline mission.
This is the same type of power source used by the Voyager and
Pioneer Jupiter spacecraft in their outer-planet missions.
Most spacecraft are stabilized in flight either by
spinning around a major axis, or by maintaining a fixed
orientation in space, referenced to the Sun and another star.
Galileo represents a combination of these techniques, and is
the first dual-spin planetary spacecraft. A spinning section
rotates at 3 rpm, and a "despun" section is counter-rotated
to provide a fixed orientation for cameras and other remote
sensors. A star scanner on the spinning side is used to
determine orientation and spin rate; gyros are used for
turns and instrument pointing.
Instruments which measure fields and particles,
together with the main antenna, the power supply, the
propulsion module, most of the computers and control
electronics, are mounted on the spinning section. The
instruments include magnetometer sensors mounted on a 36-
foot (11-meter) boom to escape interference from the
spacecraft; a plasma instrument detecting low-energy charged
particles and a plasma-wave detector to study waves generated
by the particles; a high-energy particle detector; and a
detector of cosmic and Jovian dust. It also carries the Heavy
Ion Counter, an engineering experiment added to assess the
potentially dangerous charged-particle environments the
spaceraft flies through, and an added Extreme Ultraviolet
detector associated with the UV spectrometer on the scan
platform.
The despun section carries instruments and other
equipment whose operation depends on a steady pointing
capability. The instruments include the camera system; the
near-infrared mapping spectrometer to make multispectral
images for atmosphere and surface chemical analysis; the
ultraviolet spectrometer to study gases; and the
photopolarimeter-radiometer to measure radiant and reflected
energy. The camera system is expected to obtain images of
Jupiter's satellites at resolutions from 20 to 1,000 times
better than Voyager's best.
This section also carries a dish antenna to track
the probe in Jupiter's atmosphere to pick up its signals for
relay to Earth.
GROUND SYSTEMS
Galileo communicates with Earth via NASA's Deep
Space Network (DSN), which has a complex of large antennas
with receivers and transmitters located in the California
desert, in Australia and in Spain, linked to a network
control center at JPL in Pasadena, California. The
spacecraft receives commands, sends science and engineering
data, and is tracked by doppler and ranging measurements
through this network. The German Space Operations Center and
tracking station at Weilheim will also support Galileo
cruise science activities beginning in September 1991.
At JPL, mission controllers including about 275
scientists, engineers and technicians supported the mission
at launch; nearly 400 will support Jupiter operations. Their
responsibilities include commanding the spacecraft,
interpreting the engineering and scientific data it sends in
order to understand how it is performing and responding, and
analyzing navigation data obtained by the Deep Space Network.
The controllers use a set of complex computer programs to
help them control the spacecraft and interpret the data.
As indicated above, the Galileo spacecraft carries
out its complex operations, including maneuvers, scientific
observations and communications, in response to stored
sequences which are sent up to the orbiter periodically
through the Deep Space Network in the form of command loads.
Designing these sequences is a complex process
balancing the desire to make certain scientific observations
with the need to safeguard the spacecraft and mission. The
sequence design process itself is supported by software
programs, for example, which display to the scientist maps of
the instrument coverage on the surface of a satellite for a
given spacecraft orientation and trajectory. Notwithstanding
these aids, a typical 3-day satellite encounter will take
efforts spread over many months to design, check and recheck.
The controllers also use software designed to check the
command sequence further against flight rules and
constraints.
The spacecraft regularly reports its status and
health through an extensive set of engineering measurements.
Interpreting these data into trends and averting or working
around equipment failures is a major task for the Galileo
flight team. Conclusions from this activity become an
important input, along with scientific plans, to the sequence
design process. This too is supported by computer programs
written and used in the mission support area.
Navigation is the process of estimating, from radio
range and doppler measurements, the position and velocity of
the spacecraft to predict its flight path and to design
course-correcting maneuvers. These calculations must be done
with computer support. The Galileo mission, with its complex
gravity-assist flight to Jupiter and 10 gravity-assist
satellite encounters in the Jovian system, is extremely
dependent on consistently accurate navigation.
In addition to the programs which directly operate
the spacecraft and are periodically transmitted to it, the
mission operations team uses software amounting to 650,000
lines of programming code in the sequence design process;
1,615,000 lines in the telemetry interpretation; and 550,000
lines of code in navigation. These all had to be written,
checked, tested, used in mission simulations and, in many
cases, revised before the mission could begin.
Science investigators are located variously at JPL
or at their home laboratories, linked by computer
communications. From either location, they are involved in
developing the sequences affecting their experiments and, in
some cases, helping to change preplanned sequences to follow
up on unexpected discoveries with second looks.
JUPITER'S SYSTEM
Jupiter is the largest and fastest-spinning planet
in the solar system. Its radius is more than 11 times
Earth's, and its mass is 318 times that of our planet. It is
made mostly of light elements, principally hydrogen and
helium. Its atmosphere and clouds are deep and dense, and a
significant amount of energy is emitted from its interior.
The earliest Earth-based telescopic observations showed bands
and spots in Jupiter's atmosphere; one storm system, the Red
Spot, has been seen to persist over 3 centuries. Atmospheric
forms and dynamics were observed in increasing detail with the
Pioneer and Voyager flyby spacecraft, and Earth-based infrared
astronomers have recently studied the nature and vertical
dynamics of deeper clouds.
Sixteen satellites are known. The four largest,
discovered by the Italian scientist Galileo in 1610, are
about the size of small planets. The innermost of these,
Io, has active sulfurous volcanoes, discovered by Voyager 1
and further observed by Voyager 2 and Earth-based infrared
astronomy. Io and Europa are about the size and density of
Earth's moon (3-4 times the density of water) and probably
mostly rocky inside. Ganymede and Callisto, further out from
Jupiter, are the size of Mercury but less than twice as dense
as water; their interiors are probably about half-and-half
ice and rock, with mostly ice or frost surfaces.
Of the others, eight (probably captured asteroids)
orbit irregularly far from the planet, and four (three
discovered by the Voyager mission in 1979) are close to the
planet. Voyager also discovered a thin ring system at
Jupiter in 1979.
Jupiter has the strongest planetary magnetic field
known; the resulting magnetosphere is a huge teardrop-shaped,
plasma-filled cavity in the solar wind pointing away from the
Sun. The inner part of the magnetic field is doughnut-
shaped, but farther out it flattens into a disk. The
magnetic poles are offset and tilted relative to Jupiter's
axis of rotation, so the field appears to wobble around with
Jupiter's rotation (just under 10 hours), sweeping up and
down across the inner satellites and making waves throughout
the magnetosphere.
MANAGEMENT
The Galileo Project is managed for NASA's Office of Space
Science and Applications by the Jet Propulsion Laboratory, a
division of the California Institute of Technology. This
responsibility includes designing, building, testing, operating
and tracking Galileo. William J. O'Neil is project manager,
Torrence V. Johnson is project scientist, Clayne M. Yeates is
science and mission design manager, Neal E. Ausman Jr. is mission
director, and Matthew R. Landano is deputy mission director. The
Federal Republic of Germany has furnished the orbiter's retro-
propulsion module and some of the instruments and is
participating in the scientific investigations. The radioisotope
thermoelectric generators were designed and built by the General
Electric Company for the U.S. Department of Energy.
NASA's Ames Research Center, Moffett Field,
California, is responsible for the atmosphere probe, which
was built by Hughes Aircraft Company, El Segundo, California.
At Ames, the probe manager is Benny Chin and the probe
scientist is Richard E. Young.
GALILEO MISSION EVENTS
Launch: STS-34 Atlantis and IUS October 18, 1989
First trajectory-change maneuver November 9-11, 1989
Venus flyby (about 10,000 mi altitude) February 10, 1990
Venus data playback November 19-21, 1990
Earth 1 flyby (about 590 mi) December 8, 1990
Asteroid Gaspra flyby (about 900 mi) October 29, 1991
Earth 2 flyby (about 200 mi) December 8, 1992
Asteroid Ida flyby August 28, 1993
Probe release July 1995
Jupiter arrival (includes December 7, 1995
Io flyby at about 600 mi, Probe entry
and relay, Jupiter orbit insertion)
Orbital tour of Galilean satellites Dec '95-Oct '97
Europa, Ganymede, Callisto
First Ganymede encounter July 1996
SPACECRAFT CHARACTERISTICS
Orbiter Probe
Mass, lb (kg) 4,890 (2,222 kg) 750 (340 kg)
Usable propellant, lb (kg) 2,035 (925) --
Height (in-flight) 20.5 feet (6.15 m) 34 in. (86cm)
Inflight span (exc. mag boom) 30 feet (9.2 m) --
Instrument payload 12 experiments 6 experiments
Payload mass, lb (kg) 260 (118) 66 (30)
Electric power RTGs, 570-480 watts Lithium-sulfur
Battery, 730 w-h
GALILEO SCIENTIFIC ESPERIMENTS
Experiment/Instrument Principal Investigator Objectives
PROBE
Atmospheric Structure, Alvin Seiff, NASA Ames RC, Temperature,
pressure, density, molecular weight profiles
Neutral Mass Spectrometer, Hasso Niemann, NASA Goddard SFC,
Chemical composition, helium abundance; Ulf von Zahn, Bonn
University, FRG, Helium/hydrogen ratio
Nephelometer, Boris Ragent, NASA Ames RC, Clouds, solid/liquid
particles
Net Flux Radiometer, L. A. Sromovsky, Univ. of Wisconsin,
Thermal/solar energy profiles; Lightning/energetic particles,
Louis Lanzerotti, Bell Laboratories, Detect lightning, measure
energetic particles
ORBITER (DESPUN)
Solid-State Imaging Camera, Michael Belton, NOAO, (Team Leader)
Galilean satellites at 1-km resolution or better, other bodies
correspondingly
Near-Infrared Mapping Spectrometer, Robert Carlson, JPL,
Surface/atmospheric composition, thermal mapping
Ultraviolet Spectrometer (includes extreme UV sensor on spun
section), Charles Hord, Univ. of Colorado, Atmospheric gases,
aerosols, etc.
Photopolarimeter Radiometer, James Hansen, Goddard Institute for
Space Studies, Atmospheric particles, thermal/reflected radiation
ORBITER (SPINNING)
Magnetometer, Margaret Kivelson, UCLA, Strength and fluctuations
of magnetic fields; Energetic Particles, Donald Williams, Johns
Hopkins APL, Electrons, protons, heavy ions in atmosphere;
Plasma, Louis Frank, Univ. of Iowa, Composition, energy,
distribution of ions; Plasma Wave, Donald Gurnett, Univ. of Iowa,
Electromagnetic waves and wave-particle interactions; Dust,
Eberhard Grun, Max Planck Inst. fur Kernphysik, Mass, velocity,
charge of submicron particles
Radio Science: Celestial Mechanics, John Anderson, JPL, (Team
Leader), Masses and motions of bodies from spacecraft tracking
Radio Science: Propagation, H. Taylor Howard, Stanford Univ.,
Satellite radii, atmospheric structure, from radio propagation
Engineering Experiment: Heavy Ion Counter, Edward Stone,
Caltech, Spacecraft charged-particle environment
INTERDISCIPLINARY INVESTIGATORS
Fraser P. Fanale, University of Hawaii
Peter Gierasch, Cornell University
Donald M. Hunten, University of Arizona
Andrew P. Ingersoll, California Institute of Technology
David Morrison, University of Hawaii
Michael McElroy, Harvard University
Glenn S. Orton, NASA Jet Propulsion Laboratory
Toby Owen, State University of New York
James B. Pollack, NASA Ames Research Center
Christopher T. Russell, University of California at Los Angeles
Carl Sagan, Cornell University
Gerald Schubert, University of California at Los Angeles
James Van Allen, University of Iowa
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.212 | | 19458::FISHER | I like my species the way it is" "A narrow view... | Fri Nov 30 1990 15:38 | 5 |
| Hmmm. Interesting. Is the probe actually incommunicado for 5 months between
the time of its release and the time it enters Jupitor's atmosphere? It sounds
like they need to be real careful of the battery power!
Burns
|
| 560.213 | GALILEO Update - November 29 | ADVAX::KLAES | All the Universe, or nothing! | Fri Nov 30 1990 15:52 | 109 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 11/29/90
Date: 30 Nov 90 00:41:40 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 29, 1990
As of noon (PST) Thursday, November 29, 1990, the Galileo
spacecraft is 4,460,520 miles from Earth and traveling at a
heliocentric speed of 64,190 miles per hour; distance to the Sun is
95,836,390 miles (1.03 AU). Round trip light time is 52 seconds.
The final pre-Earth 1 navigation delta DOR (Differential One-way
Ranging) activities were completed on November 22 using the 70 meter
antenna pairs at Goldstone/Australia and Goldstone/Spain. Both passes
were successful due to timely response at the 70 meter station in
Spain in recovering from a digital signal processor failure. A total
of 27 of the planned 27 activities are complete; 23 were successful.
Commands were sent on November 26 to set the Command Loss Timer
to 96 hours from the previous 240 hours. A NO-OP command was sent
immediately thereafter on November 28 to reset the Command Loss Timer
to 96 hours, the planned value for this mission phase.
The SSI (Solid State Imaging) instrument was powered on November 26.
Preliminary data results indicate the SSI is functioning normally.
Delay Action Commands (DACs) were sent on November 27 for planned
execution later that day. The DACs turned off downlink ranging
modulation to improve the RF performance for subsequent high rate data
transmission at 115.2 kbps. After reception of the high rate data,
the ranging modulation was restored. A similar set of DACs to improve
115.2 kbps link performance was sent on November 28 for execution on
November 29.
This was the first time the spacecraft has transmitted 115.2 kbps
data in flight; the data was properly processed and displayed by the
Ground Data System on November 29. Earlier 115.2 kbps data on
November 27 was not collected due to inadequate RF link performance
caused by a temporary loss of the Goldstone 70 meter antenna;
Goldstone was returned to service on November 28 after timely
structural repairs were completed.
The 70 meter station at Goldstone was temporarily out of service
starting Tuesday, November 27 at 11 AM (PST) due to a structural
failure in a sub-reflector kick brace. The brace was rewelded and
support was resumed on November 28 at 2:00 PM (PST). Ulysses
relinguished their Goldstone 34 meter antenna time that evening which
permitted Galileo tracking data to be obtained immediately prior to
TCM-8. Although no telemetry data was obtained, the loss is not considered
significant. The quick response by the DSN (Deep Space Network) to the
failure permitted support to resume with minimum data loss.
An SSI and NIMS (Near Infrared Mapping Spectrometer) photometric
calibration sequence was successfully completed on November 26 and 27;
data analysis is in process.
The TCM-8 (Trajectory Correction Maneuver 8) sequence memory load
was successfully sent to the spacecraft on November 28. Prior to the
execution of TCM-8, the EPD (Energetic Particles Detector) was moved
to Sector O, the minimum contamination position; EPD was returned to
Sector 4 after the maneuver.
The spacecraft properly executed the maneuver later on November
28. The maneuver was comprised of one positive Z segment using the
P1A thruster and one lateral segment using the L thrusters. Spacecraft
performance throughout the maneuver activity was excellent. RPM
(Retro Propulsion Module) tank pressures and L1B thruster/cluster
temperatures were near predicted levels. The P1A and L2B thruster
temperatures were not available due to failure of these temperature
interfaces months earlier. No spin rate or attitude pointing
corrections were required between burn segments or at the end of the
maneuver activity. Preliminary radio frequency tracking data
indicates about a 1.5 percent overburn on the P1A thruster;
performance of the "L" thruster was near perfect.
A SITURN to lead the Sun was successfully performed on November
28. The turn, about 6 degrees, resulted in the spacecraft leading the
sun by about 9 degrees. Spacecraft performance during the activity
was normal and without incident.
The AC bus imbalance measurement fluctuated several DN and is
stable near 45.5 volts. The DC measurement exhibited large
fluctuations from near 2 volts to 18 volts (135 DN change) and then
returning to near 1 volt (150 DN change) a day later. DC fluctuations
occurred within about a 1 hour period. The spacecraft operation was
quiescent during the time these DC measurement changes occurred. All
other power-related measurements and spacecraft telemetry are normal.
The Project reviewed and approved the preliminary sequence and
command products for VE-12 (Venus-Earth 12) on November 26. The VE-12
sequence controls spacecraft activities from December 17 to February 18,
1991.
An S-Band Array Test with the two 34 meter antennas at Goldstone
is scheduled for Tuesday, December 4. The purpose of this test is to
calibrate an increase in gain to determine if this configuration
should be considered for the Earth 2 flyby in 1992.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.214 | Re: .212 - Pioneer Venus precedent | 4347::GRIFFIN | Dave Griffin | Fri Nov 30 1990 16:38 | 11 |
| The Pioneer Venus probes were all released a number of weeks before the
planet encounter. Each probe had a timer (which had to be set *just right*)
which would activate the probe as it entered the atmosphere. The Venus
probes were transmit-only and battery reserves were tight, so the timing
was very important.
I can't say if the same approach is being used for Galileo - but it is the
most economical (and perhaps reliable) way to do it (that I can think of).
- dave
|
| 560.215 | A great moment in engineering?? | 8713::J_BUTLER | USAR...and ready... | Fri Nov 30 1990 18:19 | 21 |
| Slowing from 100,000 mph to about Mach 1 (say 750 mph) in about
2 minutes before deploying it's parachute!
Can anyone calculate the deceleration in feet per second per second
that would require?
Does anyone know any of the designs of the probe that allow it to
survive such a force? I understand the aeroshell, but its the
capability of the electronics (sensors, transmitters, circuits,
etc) to withstand such stresses?
This MUST be one of the GREAT moments in engineering, but I have
heard nothing about *how they can expect it to survive*
to deploy its 'chute (that requires MOVING parts!) let alone
sending data for 75 minutes afterwards!
(and if I hear "captured UFO technology," I think I'll SCREAM!!)
many :) s
John B.
|
| 560.216 | | 29083::J_MARSH | Svelte & Petite-nosed | Fri Nov 30 1990 20:08 | 9 |
| 560.217 | Not as bad as you might think... | 19458::FISHER | I like my species the way it is" "A narrow view... | Fri Nov 30 1990 20:15 | 3 |
| Or about 37 Gs to use old-fashioned planetocentric measurements.
Burns
|
| 560.218 | | 37653::SCOLARO | | Mon Dec 03 1990 02:21 | 6 |
| Umm, I could be wrong about this, but doesn't the mach 1 refer to a
jovian mach 1? AND, if the jovian atmosphere at that level is less or
more dense, the number could be quite higher than 750 mph or
considerably lower.
Tony
|
| 560.219 | Wind/Parachute Question | 28890::MFORBES | This Space Intentionally Left Blank | Mon Dec 03 1990 12:51 | 5 |
| While watching The Infinite Viyage the other night, a question occured to
me. They mentioned thet the Jovian winds blow at 300 mph. How is a parachute
going to survive in 300 mph winds.
Mark
|
| 560.220 | A little history | PRAGMA::GRIFFIN | Dave Griffin | Mon Dec 03 1990 13:38 | 30 |
| Re: .219, .215
While Galileo and its probe are surely wonderful instruments, they
may not represent a major engineering achievement. The Pioneer
Venus mission (conceived back in the early 1970's and achieved in 1978)
ran a similar mission to Venus using both an orbiter and a multiprobe
bus which sent 4 atmospheric probes into the Venus atmosphere.
(The Russian Venera series probably achieved these goals even earlier
-- I don't have detailed information on the engineering of Venera).
The Pioneer Venus (PV) multiprobe bus contained 3 small probes and
one large one. The large probe used a parachute during its descent.
The large probe decelerated from 26,000 to 452 mph (41,800 to 727
km/hr) in 38 seconds, at which point the parachute opened. Peak
deceleration was 280g for the large probe (the small probes had
decelerations between 200 and 565 g).
The parachute development for PV was one of the trickier pieces of
engineering. Many of the initial tests (of the ones they thought
would work) with prototypes had the parachute disintegrating
after deployment (they were photographing it at 200 frames/second,
and in one frame the parachute was there, and the next it was not!)
I don't want to take anything away from the Galileo project, because
I haven't the foggiest idea if the stresses are anywhere nearly the
same, but the numbers are in the same general area so I thought I'd
note the historical precedents.
- dave
|
| 560.221 | ballutes | 58205::ALLEGREZZA | George Allegrezza @VRO | Mon Dec 03 1990 14:13 | 7 |
| Re: high-speed parachute deployment
I don't know about Galileo, but a number of US military programs have
used ballutes (balloon-shaped ribbon parachutes) to slow reentry
vehicles from well above Mach 2 to enable recovery. Often the ballute
acts as a drogue, slowing the vehicle enough to allow a larger, more
conventional parachute to be deployed.
|
| 560.222 | | JANUS::BARKER | Jeremy Barker - T&N/CBN Diag. Eng. - Reading, UK | Mon Dec 03 1990 15:03 | 4 |
| I seem to remember reading something earlier this year about parachutes
deployable at supersonic speeds - probably in Scientific American.
jb
|
| 560.223 | RE 560.220 | ADVAX::KLAES | All the Universe, or nothing! | Mon Dec 03 1990 16:23 | 11 |
| The Soviets started successfully deploying their VENERA atmosphere
and surface probes in 1967 with VENERA 4, which survived the decelera-
tion and descent through the thick Venerean atmosphere, but not the
crushing air pressure at the lower depths. It had only been designed
to withstand 20 Earth atmospheres, based on the best information at
that time. Venus' surface pressure is now known to be 90 Earth at-
mospheres, or the equivalent of being 990 meters (3,300 feet) under
Earth's oceans.
Larry
|
| 560.224 | | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Mon Dec 03 1990 16:31 | 8 |
| re .218
Someone just chose earth surface mach 1 as a reference point for a
quick calculation. But you are right, without qualifying the
conditions, 'mach 1' is a meaningless term for absolute velocity. The
press misuses it a lot.
gary
|
| 560.225 | re. Mach 1 and parachuting in a wind | 42110::RICKETTS | Have you tried kicking it? | Tue Dec 04 1990 08:40 | 37 |
| re .218 et seq.;
Even if Mach 1 was 10 times greater in the uppermost part of the
Jovian atmosphere than it is at the earth's surface the deceleration
would not change much. 100,000mph to 7,500mph in 2 minutes is not
all that much different from 100,000mph to 750mph in the same time.
(Figures are approx., so don't flame me with the exact speed at
stp! 8*)) I suspect that the Jovian Mach 1 (at the relevant altitudes)
is probably considerably greater than at the earth's surface. The
pressure is lower (@100mb when the probe deploys its parachute),
and the density will probably also be much lower, if the uppermost
part of the atmosphere consists mainly of hydrogen. If I remember
aright, both these factors increase the speed of sound. I expect
we will find out for certain when it gets there.
re. .219;
The wind speed doesn't really matter to a parachute; just its
own speed relative to the air around it when it deploys. How fast
that air is moving over the surface (which is what wind speed means)
is irrelevant. It matters if you are trying to soft land something,
be it a space probe or a parachutist, because they will be travelling
across the ground with the wind (assuming a straightforward parachute,
rather than a paraglider or the like). Landing under a parachute in a
300mph wind would be rather like jumping out of a plane flying along 4'
above the ground at a speed of 300mph. The probe is expected to stop
working long before it approaches whatever might pass for a solid
surface on Jupiter, so this is not a problem.
Actually, the parachute seems rather a small one, even if the probe
is dropping most of its mass before descending. If the weight given
(750lbs) means its weight on the earths surface, then it will actually
*weigh* rather more on Jupiter. Even if it sheds 90% of its mass
with the heatshield etc., it would still weigh a couple of hundred
lbs under Jovian gravity (anyone know just how much?). All descending
under an 8' canopy; sounds more like a drogue rather than a proper
parachute, though of course it will have more braking effect when it
gets into the denser part of the atmosphere.
Ken
|
| 560.226 | Questions Questions Questions | 42399::CHRIS | Capacity! What Capacity ? | Tue Dec 04 1990 10:43 | 14 |
| Hello,
I have a few questions regarding the probe:
1. How deep will the probe penetrate into the Jovian atmosphere
before it fails.
2. What are the pressures at this depth, i.e., will it be battery
exhaustion or conditions destroying the probe
I hope someone can answer these questions cheers,
Chris
|
| 560.227 | Thanks! | 8713::J_BUTLER | USAR...and ready... | Tue Dec 04 1990 13:15 | 5 |
| Thanks for all the good information on the probe! I am a bit
more confident that it will survive long enough to return
good data!
John B.
|
| 560.228 | Speed of Sound Factor | 2622::DAHL | Tom Dahl, CDMS | Tue Dec 04 1990 13:20 | 3 |
| The speed of sound in a gasseous medium is dependent on the temperature of the
medium, not the pressure or density in any way.
-- Tom
|
| 560.229 | Ida and Gaspra - GALILEO's planetoid targets | ADVAX::KLAES | All the Universe, or nothing! | Tue Dec 04 1990 20:45 | 34 |
| From: tholen@uhccux.uhcc.Hawaii.Edu (David Tholen)
Newsgroups: sci.astro
Subject: Re: Galileo Fact Sheet
Date: 2 Dec 90 00:37:42 GMT
Organization: University of Hawaii
Ron_Baalke@f110.n771.z3.fidonet.org (Ron Baalke) writes:
> Ida is about
> 20 miles or 30 kilometers across; like Gaspra, it is believed
> to represent the majority of main-belt asteroids in
> composition, though there are believed to be differences
> between the two.
Both Gaspra and Ida are classified as S-type asteroids, which
dominate only the inner part of the asteroid belt. The outer part is
dominated by C-type asteroids. Overall, C-types are believed to
outnumber S-types, but fewer C-types have actually been discovered,
simply because their lower albedos and greater average distances from
the Sun make them fainter than the average S-type, thus biasing
against their discovery. So it isn't technically correct to say that
Gaspra and Ida "represent the majority of main-belt asteroids in
composition", though the reason for the confusion should be obvious
from this discussion.
Regarding the list of investigators participating in the mission,
> David Morrison, University of Hawaii
> Toby Owen, State University of New York
David Morrison is now at NASA's Ames Research Center and has been
for a couple of years. Toby Owen is now at the University of Hawaii's
Institute for Astronomy, where he assumed a position in March of this year.
|
| 560.230 | Galileo Status - 12/4/90 | PRAGMA::GRIFFIN | Dave Griffin | Wed Dec 05 1990 12:14 | 36 |
| From: gull@stars.dnet.nasa.gov
Date: 5 Dec 90 00:48:56 GMT
Organization: University of Virginia
GALILEO MISSION STATUS
December 4, 1990
The Galileo spacecraft is just over 2 million miles and 4
days from its Earth gravity assist. It is approaching Earth from
outside Earth's orbit, and will cross behind our planet and fly
over its sunward side in order to gain energy from the Earth.
This energy is needed to raise Galileo's orbit, first to the
Asteroid Belt and, in a second gravity assist, finally to meet
Jupiter in 1995.
Spacecraft speed in its orbit around the Sun is 65,800 mph,
still increasing gradually as Galileo comes closer to Earth's
orbit and to the Sun. On December 8, the Earth gravity assist
will occur during the half-hour surrounding 12:35 p.m. PST, the
time of closest approach. This boosts Galileo's orbital speed by
about 11,500 mph.
Spacecraft health and mission performance continue to be
excellent. Over the last two weeks Galileo played back the Venus
science data, stored on tape since last February, carried out a
variety of science instrument calibrations and engineering
operations, and successfully completed the last and smallest of
the trim maneuvers scheduled before the Earth gravity assist.
The spacecraft is now well within the trajectory
window for the required gravity assist. It will attain a
closest-approach altitude of about 590 miles at 12:35 p.m.
PST on Saturday, December 8. A press conference to discuss
the gravity assist and other Galileo activities near Earth
is scheduled for December 8 at 1:30 p.m. PST at JPL (and via
the NASA SELECT satellite link).
|
| 560.231 | On Gravity Assists | 2631::DAHL | Tom Dahl, CDMS | Wed Dec 05 1990 13:56 | 22 |
| RE: 560.230
> The Galileo spacecraft is just over 2 million miles and 4
>days from its Earth gravity assist....
>...On December 8, the Earth gravity assist
>will occur during the half-hour surrounding 12:35 p.m. PST, the
>time of closest approach.
Surely the gravity assist is a continuous phenomenon that has been occuring for
some months now, as the spacecraft has been approaching Earth. The above
wording sounds like magically a boost is given during a 30 minute period. The
boost culminates at the time of closest approach. Then a "negative boost"
begins to occur, where the spacecraft is slowed down by Earth's gravity, which
continues for a while as the spacecraft gets farther away and gradually tapers
to essentially nothing. There has been a net positive effect because the
time spent in positive acceleration (toward the Earth) is longer than the time
spent in negative acceleration (going away from the Earth). This time
difference is in turn because of the flight path difference before/after:
the approach to earth has been on a track relatively parallel with the Earth's
motion, whereas the separation from Earth is on a track more sharply off the
Earth's orbital motion path.
-- Tom
|
| 560.232 | Just want to stand on the lawn and wave ;^) | 30086::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Wed Dec 05 1990 14:45 | 2 |
| Will there be any possibility of observing this encounter in the New
England states and what is the window/position for it to be viewed?
|
| 560.233 | | PRAGMA::GRIFFIN | Dave Griffin | Wed Dec 05 1990 16:12 | 16 |
| Re: .231
I'm sure you're technically correct. If you are willing to remember that
these are press releases then perhaps you can say that the "assist"
part really happens during the closest encounter, since that is when the
biggest chunk of the delta-vee is transferred, and when the most severe
trajectory change is made. If Galileo just flew by, it certainly would
gain some speed but it wouldn't be considered a useful assist unless it
hits that corridor.
Re: .232
Unless you happen to live in Iberia, you won't be able to see it.
- dave
|
| 560.234 | GALILEO Press Conference on December 8 | ADVAX::KLAES | All the Universe, or nothing! | Thu Dec 06 1990 14:26 | 39 |
| From: yee@trident.arc.nasa.gov (Peter E. Yee)
Newsgroups: sci.space
Subject: Galileo Earth flyby news conference (Forwarded)
Date: 5 Dec 90 22:58:59 GMT
Sender: usenet@news.arc.nasa.gov (USENET Administration)
Organization: NASA Ames Research Center, Moffett Field, CA
[Ron Baalke seems to be having troubles with mars.jpl.nasa.gov, so I
am posting Galileo and other reports that he normally handles. -PEY]
Paula Cleggett-Haleim
Headquarters, Washington, D.C. December 5, 1990
(Phone: 202/453-1547)
Robert MacMillin
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
N90-97
NOTE TO EDITORS: GALILEO EARTH FLYBY NEWS CONFERENCE
Scientists from NASA's Jet Propulsion Laboratory will hold a
news conference at 4:30 p.m. EST on Saturday, Dec. 8, to discuss the
Galileo spacecraft's flyby of Earth, report on the spacecraft and
misison status, and outline ongoing scientific observations of Earth.
Galileo will fly by Earth as part of its gravity-assisted
path to Jupiter on Dec. 8. It will be closest to Earth (about 590
nautical miles) at 3:35 p.m. EST.
Press conference participants will include Project Manager
William J. O'Neil, Mission Director Neal E. Ausman Jr., Project
Scientist Torrence V. Johnson, and Science and Mission Design Manager
Clayne M. Yeats.
The conference will be carried live on NASA Select television,
Satcom F2R, Transponder 13, C-Band.
|
| 560.235 | 8 Dec Earth flyby .. | 52331::ANDRADE | The sentinel (.)(.) | Wed Dec 12 1990 06:32 | 2 |
| Any news on this. How did the Galileo Earth Gravity assist maneuver go.
Dec 8 has come and gone, and not a beep.
|
| 560.236 | | 30086::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Wed Dec 12 1990 11:12 | 4 |
| The manuever was called a success in the news reports here. They also
mentioned that the shuttle crew were supposed to spot it with
binoculars. Did they and were any pictures taken that will be made
available later?
|
| 560.237 | | 2319::SAUTER | John Sauter | Wed Dec 12 1990 14:20 | 33 |
| NASA Select was switching between Astro-1 and Galileo near the time of
closest approach. I think NASA is learning how to operate like a
commercial network, though they have a long way to go if they are
aiming for the professionalism of CNN, for example.
Several minutes before closest approach they switched Galileo to using
the backward-facing antenna, so they would get telemetry while
the satellite was leaving. They were surprised to discover that
they could still get signals after the switch. In fact, they said
that Madrid followed Galileo all the way to the horizon.
The point of closest approach to Earth was over the horizon for all
the tracking stations, but Goldstone picked it up shortly after that
point, and subsequently handed over to the Australian station.
They were quite proud of the handover execution---it seems that the
Deep Space Network isn't accustomed to tracking objects that cross
a large number of degrees in a short time!
The shuttle crew did not report seeing Galileo, and so the ground
people were assuming that it had not been seen, since they would have
been excited if they had spotted it. The clostest approach to the
shuttle was around 2000 miles, so their chances weren't very good.
NASA Select showed some preliminary pictures of Australia taken by
Galileo as it pulled away from Earth.
They also explained how passing the Earth can convert a 1-year orbit
that encounters Venus into a 2-year orbit that encounters an asteroid,
and another pass generates a 6-year orbit that encounters Jupiter.
The explanation was convincing, but I can't reproduce it without
a blackboard.
John Sauter
|
| 560.238 | GALILEO Updates - November 30-December 11 | ADVAX::KLAES | All the Universe, or nothing! | Wed Dec 12 1990 18:13 | 527 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/30/90
Date: 11 Dec 90 03:55:39 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
November 30, 1990
Yesterday, the Galileo spacecraft completed planned calibration
activities for the remote science instruments and the Magnetometer instrument.
Today, commands will be sent to power on the relay radio hardware oscillators
in preparation for Probe checkout activities on December 4. No spacecraft
sequencing activity is planned over the weekend on December 1 and 2.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/03/90
Date: 11 Dec 90 04:02:43 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 3, 1990
Things are going well with the Galileo spacecraft. The relay radio
hardware oscillators were successfully powered on November 30 in preparation
for the planned Probe checkout on December 4. In addition to the powering of
the relay radio hardware oscillators on November 30, several other Galileo
heater electrical loads were successfully configured. Today, the Command Loss
Timer will be reset from 4 days to 3 days, its planned value for this mission
phase. Tomorrow, the Probe checkout, system functional test, will be performed.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/04/90
Date: 11 Dec 90 04:12:34 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 4, 1990
The Galileo spacecraft health continues to be excellent. Yesterday, the
Command Loss Timer was successfully reset to 3 days, its planned value for this
mission phase. Also yesterday, selected engineering electrical heaters were
properly configured to provide adequate power margin for the Probe checkout
activity. Today, the second in-flight Probe checkout will be performed. The
first checkout was performed in late October 1989 several days after launch and
was successful. Tomorrow, the VE-11 (Venus-Earth 11) Earth 1 Encounter sequence
will be sent to the spacecraft.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/05/90
Date: 11 Dec 90 04:21:27 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO EARTH FLYBY STATUS REPORT
December 5, 1990
The Galileo spacecraft will make an Earth gravity assist on December 8,
1990 at 12:34:34 PM (PST). The spacecraft will approach the Earth from the
night side and make it closest approach over the Atlantic Ocean (25.2N
Latitude, 63.5W Longitude) at an altitude of 593 miles. Galileo will make
numerous measurements of the Earth/Moon system before, during and after the
flyby. Listed below are the science observations that will be made by each
of science instruments onboard the spacecraft.
SOLID STATE IMAGING SYSTEM (SSI) - Provides high-resolution images in
the visible light with at 1500mm telescopic camera. The sensor is an
actively-cooled, tantalum-shielded Charge Coupled Device (CCD) of 800 x 800
pixels. Color pictures are obtained by combining images taken through
different filters. The camera's best observations will detect objects as
small as 20 meters. The SSI was checked out in December 1989 and had a
successful Venus encouter. 919 shutters and 120 filter wheel steps has
been performed since launch. Earth flyby objectives:
Earth:
o Conduct ground truth studies and images system characterization.
o Earth imaging to form movies:
- "Powers-of-Ten" feature track movie. Will start at 45 minutes
Earth Closest Approach (ECA +45 minutes).
- Zoom/Departure movie, will take images of the Earth after ECA
and will continue to do for several days after ECA.
- Spin movie, at ECA +2 days, 17 hours to ECA +3 days, 18 hours, will
take images of one complete Earth rotation, which will be combined
to form a spin movie.
Moon:
o Impact basin formation and evolution using the Orientale Basin.
o Highland crustal heterogeneity.
o Mare basalt distribution and characterization.
o Nearside-farside asymmetries (maria and highlands).
o Nature, origin and distribution of farside non-Mare volcanism.
o South polar highlands and Mare crustal stratigraphy.
o Physical characteristics of lunar surface via photometric study.
DUST DETECTOR SUBSYSTEM (DDS) - Determines the velocity, mass, charge
and flight direction of sub-micron-sized particles. Sensitive to dust
particle mass of 10^-16 grams to 10^-6 grams. Up to 100 particles/sec
can be detected. The DDS cover was deployed on December 27, 1989, and the
instrument was powered on December 28, 1989, and has remained on ever since.
Cruise science data has been recovered from 61 DDS memory readouts. Earth
flyby objectives:
o Search for evidence of an Earth shepherded dust ring at 1 AU.
o Investigate dust-magnetosphere interations (ie. swarms of dust
particles) inside the magnetotail and magnetosphere.
o Search for space debris inside 36,000 km and particularly at perigee.
o Search for lunar ejecta while the Moon is within the field of view
(mainly after closest approach).
o Improve instrument calibration by characterizing the noise in each
of the ion collector, electron collector and channeltron.
MAGNETOMETER (MAG) - Monitors and measures magnetic fields for strength
and fluctuations in the spacecraft's immediate environment. The MAG
instrument was first powered on October 19, 1989, and has remained on
continuously with the exception of the spacecraft safing event in January
1990 and the optimal averager anomoly in July 1990. Cruise science data has
been recoveredf from 49 MAG memory readouts. On June 8, 1990, a storage
pointer was overwritten in the MAG executive program. This was a result of
a programming error, and the problem has since been identified, and the
MAG memory was reloaded on August 6, 1990. Earth flyby objectives:
o High-time resolution magnetic field data (snapshots) will be taken
during the bowshock crossing. Multiple shock crossings are estimated
between 2:35 PM (PST) and 3:05 PM on December 8, 1990.
o MAG will look for ion cyclotron waves in unique frequency band
bridging the gap between PWS data and other MAG data.
o The structure and dynamics of Earth's distant magnetotail will be
investigated.
o Solar wind data will be correlated with IMP8 (Earth orbit) data to
study the scale size of solar wind magnetic structures.
ENERGETIC PARTICLE DETECTOR (EPD) - Measures in the spacecraft's
immediate environment the energy, composition, intensity and angular
distribution of high energy charged particles (electrons, protons and
heavy ions) having energies above 20keV and extending to about 10MeV
per atomic mass unit. The EPD was checked out in December 1989 and had
limited data at Venus. Earth flyby objectives:
o Measure electron and ion fluxes and ion composition (.02 to 55 MeV)
in the distant geotail. This extends the range of energy and
composition measurements provided by ISEE 3.
o Attempt to determine the neutral energetic particle distribution
upstream of the magnetosphere.
NEAR INFRARED MAPPING SPECTROMETER (NIMS) - Measures the thermal,
compositional and structural nature of its targets in infrared. Checked
out in December 1989 and had a successful Venus operation. Earth flyby
objectives:
Earth:
o Mespheric water content - relation to potential methane increases
and noctilucent cloud occurrences.
o Geological and biolgical mapping of Australia and Antarctica:
- New Biological data in 3.5 hydrocarbon bands (C-H stretching).
- Antactic snow reflectance data for climatology.
- Geological remote sensing and ground truth.
o Global mapping:
- Spectral properties of vegetation.
- Organic content of oceans and seas (phytoplankton).
- Global distribution of atmospheric methane and organics.
Moon:
o Newly observed territory.
o Search for hydrated minerals.
o Extended phase angle coverage.
ULTRAVIOLET SPECTROMETER (UVS) and EXTREME ULTRAVIOLET SPECTROMETER
(EUV) - Measures gases and aerosols and looks for complex molecules. The
UVS has been on since a 4 day checkout on December 27, 1989, and has made
Venus observations and Lyman Alpha background surveys during cruise. The
EUV was cross calibrated with the UVS in December 1989. The EUV made Venus
observations, making ongoing sky background maps, and successfully observed
Comet Levy. Earth flyby objectives:
o Obtain Lyman Alpha maps with 10 degree resolution over the entire
anti-Sun hemisphere.
o Search for possible lunar atmospheric constituents, ie. H, He, O, S, OH.
o Obtain H and OH maps of the entire Earth-Moon system.
o Measure ozone abundance at various Earth latitudes.
o Map the Earth's night airglow emissions NO. (2363), NO (1980) and
altitude variations.
o Map the Earth's geotail and magnetosphere from 250 R+ to 1 R+ in
Lyman Alpha, He 584 Angstroms and O+ 834 Angstroms.
o Search nightside to dayside exosphere for H, He and O+ emissions.
o Map the interstellar wind and density profile for the He cone from
7000 R+ to 250 R+.
PHOTOPOLARIMETER RADIOMETER (PPR) - Observes light in the visible and
infrared wavelengths, provides data on atmospheric composition and thermal
energy distribution. Operated at Venus, and recently turned back on. Earth
flyby objectives:
o Make polarization measurements over clear and cloudy regions of the
South Pacific to test capability of cloud particle detection.
o Measure Earth's radiation budget to test PPR capability.
o Map the polarized light from the Moon between phase angle of 20 to
150 degrees to TEST PPR capabilities.
PLASMA SUBSYSTEM (PLS) - Measures the composition, energy, temperature
density, and three dimensional distribution and bulk motions of low energy
plasma (ions) in the spacecraft's immediate environment. The instrument's
range is from 1V to 50kV with 5 second temporal resolution. The PLS was
checked out in December 1989 and had 4 hours operation at Venus. Earth flyby
objectives:
o Characterize the dynamics of the plasma environment in the Earth's
magnetosphere.
o First simultaneous measurements of both ion and electron flows to
characterize current system.
o First definitive measurement of plasma composition in the magnetotail
to determine source of plasma.
o Search for charged oxygen in plasmoids to discern plasmoid/plasma
sheet association.
PLASMA WAVE SYSTEM (PWS) - Detects electromagnetic waves and analyzes
wave-particles interactions in three dimensions. Uses a dipole antenna
comprising of two 10 meter graphite-epoxy antennas at the tip of the
Magnetometer boom, and search coils in the High Gain Antenna reflector
structure. The PWS was checked out in December 1989 and collected 1 hour
of Venus data. Earth flyby objectives:
o Characterize plasma waves and radio emissions in the distant
magnetotail.
o Obtain a complete set of low rate science plasma wave observations
extending from the solar wind through the dawnside magnetosphere.
o First wideband observations of both electromagnetic and electrostatic
waves in the solar wind and Earth's magnetotail/magnetosphere.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 12/05/90
Date: 11 Dec 90 04:30:23 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 5, 1990
Yesterday, the Probe checkout activity was successfully completed on the
Galileo spacecraft. Preliminary "Quick-look" analysis indicates that Probe
operation was normal and the health of the Probe is excellent.
Early today, the spacecraft downlink telemetry rate was increased to
134.4 Kbps, the maximum rate available from Galileo. This is the first
in-flight use of this data rate; data is successfully being processed and
displayed by the Ground Data System (GDS).
Today, the major activities already completed include updating the
system fault protection response to select LGA-2 (Low Gain Antenna 2), and
resetting the Command Loss Timer to 3 days, its planned value for this mission
phase. Later today the VE-11 (Venus-Earth 11) Earth encounter sequence memory
load will be transmitted.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/07/90
Date: 11 Dec 90 04:36:49 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 7, 1990
Today at 8 a.m. PST the VE-11 Earth encounter sequence stored on board
the Galileo spacecraft became active. Several commands were sent today to
disable solar-related attitude control functions in preparation for the sun
occultation during tomorrow's Earth flyby. Also several other commands were
sent to fine tune the Galileo power margin, to relocate the remote science
platform, and to reset the Command Loss Timer to 3 days. Tomorrow the Galileo
spacecraft will make its closest approach to Earth at 12:35 p.m. PST at an
altitude of about 595 miles. Earth 1 Encounter science data collection
activities are planned into next week.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/06/90
Date: 11 Dec 90 04:34:13 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 6, 1990
Yesterday, in preparation for the Earth flyby, the Galileo spacecraft
attitude control system was successfully commanded from cruise mode to
inertial mode using gyros for control. Also yesterday, the VE-11
(Venus-Earth 11) Earth 1 Encounter sequence program was successfully
transmitted and received by the spacecraft. The encounter sequence will
become active at 8 a.m. PST tomorrow. Tomorrow a command will be sent to
reset the Command Loss Timer to 3 days, its planned value for this mission
phase.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 12/07/90
Date: 11 Dec 90 04:40:56 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 7, 1990
As of noon (PST) Thursday, December 6, 1990, the Galileo spacecraft is
1,066,990 miles from Earth and traveling at a heliocentric speed of
66,485 miles per hour; distance to the Sun is 92,611,910 miles (0.99 AU).
Round trip light time is 0 minute, 14 seconds.
A NO-OP command was sent on November 30 to reset the Command Loss Timer
to 96 hours. The Command Loss Timer was subsequently reset from 96 hours to
72 hours on December 3. NO-OP commands to reset the timer were sent, as
planned, on December 3, 4, and 5.
A star vector update was successfully performed on November 30. This
updated star information will be used for the forthcoming sequence activities.
Commands were sent on December 1 to reduce the telemetry downlink data
rate from 115.2 kbps to 7.68 kbps. The lower data rate was selected to
guarantee high quality data return consistent with RF link performance. On
December 3, commands were sent to restore the downlink telemetry rate to 115.2
kbps consistent with link performance and the on-board sequence expected data
rate.
The Relay Radio Hardware (RRH) oscillators were successfully powered on
November 30 in preparation for the Probe checkout on December 4. Several
engineering electrical heaters were configured on November 30 and December 4
to assure adequate power margin to support the Probe checkout.
The Probe checkout was successfully performed on December 4. All power
consumption and thermal profiles were near predicted levels. Preliminary
analysis indicates probe operation was normal and no unexpected probe events
were observed; an initial assessment concludes the Probe health is excellent.
A brief real-time data outage, due to a ground communication intermittent
problem, occurred just prior to the initial pump down of the Neutral Mass
Spectrometer (NMS) thereby precluding real time evaluation of Argon gas
buildup since the first flight probe checkout in October 1989. The data lost
during the outage was subsequently retrieved from tapes and provided to the
probe personnel; analysis is in process.
Commands were sent on December 5 to change the on-board automatic fault
protection response to select Low Gain Antenna 2 (LGA-2). These commands
configure the fault protection to a state consistent with the planned antenna
switch from LGA-1 to LGA-2 on December 8.
The spacecraft's downlink telemetry data rate was increased to 134.4 kbps
via the stored sequence on December 5. This data rate is the spacecraft's
maximum designed data rate and this was the first in-flight use of this rate;
the data was successfully received and processed by the Ground Data System
(GDS).
The VE-11 (Venus-Earth 11) Earth 1 encounter sequence memory was
successfully transmitted and received by the spacecraft in two parts, Part A
on December 5 and Part B on December 6. The VE-11 sequence will go active on
December 7 and control spacecraft events to December 17.
Commands were sent on December 5 to turn on the PLS (Plasma) instrument's
high voltage in preparation for data collection during the Earth 1 encounter.
Several Delayed Action Command (DACs) were also sent on December 5 for
execution on December 8. These commands will power off the PLS instrument and
turn on its electrical replacement heater shortly prior to closest approach.
This action assures the PLS instrument remains within safe thermal limits
established by the Principal Investigator.
The AC and DC bus imbalance measurements were relatively stable. The AC
measurement fluctuated about 3 DN and is reading near 46 volts. The DC
measurement varied about 3 DN and is reading about 2 volts, possibly
indicative of a return side leakage path to chassis between 80-150 ohms. All
other power-related measurements and spacecraft telemetry are normal.
The Project reviewed and approved the final sequence and command products
for VE-12 on December 3. The VE-12 sequence controls spacecraft activities
from December 17 to February 18, 1991. This sequence contains 9 SITURN events,
17 Sun acquisitions, 3 RPM (Retro Propulsion Module) flushing activities,
the LGA-2 to LGA-1 antenna switch, 5 windows for the CDS (Command Data
Subsystem) memory tests, attitude control calibration events, radio science
tests, UVS (Ultraviolet Spectrometer) observations, several cruise science
memory readout activities, 4 maneuver windows for TCM-9A (Trajectory
Correcition Maneuver) on December 18, 19, 20, and 21.
The Flight Control and Support Office (FCSO) and the Engineering Office
have completed analysis of prime and backup data sources to determine the
completeness of data received at JPL during the Probe checkout on December 4.
The FCSO reported that the small amount of data which was missing at JPL was
recovered from data recorded at the tracking stations. The Probe Engineering
Team (PET) was able to confirm successful completion of the Probe checkout
using the data already at JPL.
An S-Band array test with the two 34 meter antennas at Goldstone was
completed this week by the DSN (Deep Space Network). The test was apparently
not successful in realizing signal level gains through arraying. Final
conclusions, causes for the unsuccessful attempt, and plans for possible la ter
tests will be reported later after post test analysis is complete. The test
was conducted to investigate the possibility of using S-Band arraying to
reduce the Project's requirements for 70 meter station support during the
Earth 2 operations in 1992.
Data collection from last week's NIMS (Near Infrared Mapping Spectrometer)
and SSI (Solid State Imaging) photo calibration activity was unsuccessful due
to a sequence design input data error which resulted in both instruments being
pointed off the Photo Calibration Target (PCT) mounted on the science boom.
Although, the lack of this calibration data has no effect on the health and
safety of the NIMS/SSI and does not effect the Earth 1 encounter sequence, its
loss will, however, result in later than planned detailed NIMS/SSI data
reduction. Investigation into the cause of this sequence design input error
is in process. Preliminary analysis suggest a possible misinterpretation of
the reference point from which the clock angle is measured.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo article
Date: 11 Dec 90 04:45:04 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Christian Science Monitor -- 12/10/90
"Galileo Gets Earth Boost for Jupiter Trip"
"Earth received its first confirmed interplanetary visitor
Saturday as the spacecraft Galileo came within 590 miles of its
home planet's surface, scientists said."
The Monitor reports that the Earth greeted the visitor by giving it a
hefty boost to its solar orbit velocity, raising from 67,000 to 78,000
miles per hour, and assisting it toward its eventual goal of Jupiter.
The paper quotes Galileo project manager William O'Neil as
saying "we are having a great day today. Galileo just
completed a virtually perfect Earth gravity assist. We hit our
target altitude to within five miles, and our arrival time to
within a half-a-second. That's not bad for a 14-month trip or
two-thirds of a billion miles."
The paper reports that, as Galileo leaves the vicinity of the
Earth, the spacecraft will send back first-ever pictures of the
Earth and moon together as well as views of the dark side of
the moon. It will also measure the methane in Earth's
atmosphere, according to the story. (editor's note. Voyager 1
took the first ever picture of the Earth and moon together, and
there is no "dark" side to the moon, there is a "far" side.)
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/11/90
Date: 12 Dec 90 01:24:45 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 11, 1990
Yesterday, the Galileo spacecraft successfully completed a SITURN to
lead the sun, and the RPM (Retro Propulsion Module) thruster maintenance
activity and enabling of Sun Gate fault protection.
Today, the spacecraft successfully completed the Target Motion
Compensation (TMC) activity associated with the remote science pointing
platform. Earth spin movie photographs are presently in process. About
1500 of the planned 1630 remaining photographs will be taken for the spin
movie as Galileo recedes from Earth. The majority of science instruments
continue to collect valuable Earth encounter data.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.239 | GALILEO Updates - December 7-13 | ADVAX::KLAES | All the Universe, or nothing! | Thu Dec 13 1990 17:46 | 143 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #3 - 12/07/90
Date: 13 Dec 90 06:38:01 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 7, 1990
As of 9AM (PST), December 7, the Galileo spacecraft is 560,309
miles from Earth as it make its approach for an Earth gravity assist.
At 8AM, the VE-11 (Venus-Earth 11) store sequence went active. The
EPD (Energetic Particles Dectector) instrument started collecting data
from Earth's magnetotail, magnetosphere, magnetopause, and shock
boundaries, and from the solar wind in the close vicinity of Earth.
The PWS (Plasma Wave) instrument investigated the magnetotail
using the 1 and 10 kHz wideband modes to observe plasma waves and
radio emissions. This included low frequency auroral kilometric
radiation (AKR) wave activity associated with trapped and escaping
continuum radiation, Langmuir waves, and whistler mode waves. Also
investigated by the PWS was the upper hybrid resonance bands and the
electrostatic electron cyclotron harmonic bands.
At 12PM (PST), the MAG (Magnetometer) started taking high rate
data (30 vectors/sec) using the snapshot mode. This data will be used
for MAG calibrations and to search for high frequency features in the
solar wind. In addition, this sampling frequency can be correlated to
the low frequency end of the PWS search coil. While in Earth's
magnetosphere, the MAG can be absolutely calibrated with respect to
Earth's known magnetic field.
At 7:19 PM, the PPR (Photopolarimeter Radiometer) instrument
started observations to map the lunar disk while the instrument is
configured to make polarization measurements. Phase measurement were
made at approximately every 30 degrees, starting at 150 degrees and
stopping at 20 degrees.
The NIMS (Near Infrared Mapping Spectrometer) took dark level
calibrations used for Earth 1 lunar observations prior to closest approach.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/10/90
Date: 13 Dec 90 00:05:30 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 10, 1990
The Galileo spacecraft superbly completed its Earth 1 qravity
assist on December 8. Earth closest approach altitude was within 7 km
of prediction; closest approach time was within 0.4 second of prediction.
Galileo continues to collect valuable science data as part of the
Earth Encounter sequence. At present about 1800 images have been
taken with approximately 1700 more to be taken in the next few days.
The spacecraft's operating state was successfully reconfigured back to
a near cruise mode state following the Earth flyby.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/12/90
Date: 13 Dec 90 00:08:18 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 12, 1990
The Galileo spacecraft completed sending back the images for the
Earth spin movie were earlier today. All but 22 (10 contiguous in one
segment, 12 contiguous in another) of the 1500 images were
successfully retrieved. This loss was expected due to DSS (Deep Space
Station) view period constraints; the loss has a minor effect on the
integrity of the spin movie. Some of the Earth images are being shown
on the TV monitors at JPL.
Galileo, speeding away from Earth, will continue to collect
valuable Earth science data for the next several days. Tomorrow, in
addition to continued science activities, a SITURN to lead the Sun
will be performed.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: JPL Report on Galileo Earth Flyby (Forwarded)
Date: 13 Dec 90 16:15:49 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
JPL REPORT ON GALILEO FLYBY OF EARTH
Scientists from NASA's Jet Propulsion Laboratory, Pasadena,
Calif., will participate in a Blue Room Report on the Galileo
spacecraft flyby of planet Earth which took place at 3:35 p.m.
EST on Dec. 8.
The report will originate from the Jet Propulsion Laboratory
at 1 p.m. EST and will be carried live on NASA Select TV, Satcom
F2R, 72 degrees West Longitude, Transponder 13, frequency 3960.0
MHz, audio 6.8 MHz.
Media representatives are invited to monitor the report in
the NASA Headquarters 6th floor auditorium, 400 Maryland Ave.,
S.W., Washington, D.C. or from participating NASA field centers.
The Earth flyby was successfully undertaken to provide
gravitational assist to the Galileo spacecraft increasing its
flight velocity on its journey to Jupiter.
[Note: There was no date associated with when the report will be aired
on NASA Select, but I believe it was meant for today, December 13.
Ron Baalke ]
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.240 | GALILEO Update - December 13 | ADVAX::KLAES | All the Universe, or nothing! | Fri Dec 14 1990 18:28 | 27 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/13/90
Date: 13 Dec 90 20:45:20 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 13, 1990
The Galileo spacecraft continues to collect valuable science data
as it speeds away from Earth. Yesterday, in addition to science data
gathering activities, several instruments successfully completed
planned calibrations. Today the NIMS (Near Infrared Mapping
Spectrometer) instrument was powered off as planned and the spacecraft
successfuly completed a planned 6 degree SITURN to lead the sun by
about 2.5 degrees. Tomorrow, the VE-12 (Venus-Earth 12) sequence
memory load will be transmitted to the spacecraft. VE-12 controls
spacecraft activities from December 17 to February 18, 1991.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.241 | GALILEO Updates - December 8 and 14 | ADVAX::KLAES | All the Universe, or nothing! | Mon Dec 17 1990 19:51 | 418 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/08/90 (Earth Flyby)
Date: 14 Dec 90 19:23:33 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
EARTH FLYBY
December 8, 1990
At 12:35PM (PST) the Galileo spacecraft made it closest approach to
Earth. Galileo came within 597 miles of Earth and just 0.4 seconds
off the predited time. The gravity assisted enabled to pick up an
additional 11,000 mph to its velocity relative to the Sun up to a speed
of about 78,000 mph. Highlights of the day are listed below.
Prior the ECA (Earth Closest Approach) at 12:01 AM, the NIMS (Near
Infrared Mapping Spectrometer) took a thermal map mosaic of crater Langrenus
in Mare Fecunditatis on the Moon, at phase angles of 136.6 to 133.2 degrees.
A long map mode was utilized to characterize instrument response.
Subspacecraft latitude was at -6.2 degrees and longitude was t 294.4 degrees
west. The NIMS resolution was approximately 276 km.
At 2:04 AM, the SSI (Solid State Imaging) camera obtain low-light level
images of the Moon in both Earthlight and/or starlight for the purpose of
assessing the imaging system sensitivity as well as to search for the possible
presence of lunar volatiles. The SSI also did some lunar multispectral
mapping to calibrate the SSI with "ground truth" from Apollo landing sites,
to map red spots and other non-mare volcanism, and to explore unmapped areas.
At 3:15 AM, the NIMS mapped Mare Fecunditatis in the proximity of the
Messier crater at an approximate resolution of 206 km with phase angles of
122 to 126 degrees at one instrument mode. An SSI frame was also taken
with a clear filter.
At 4:21 AM, the UVS (Ultraviolet Spectrometer) instrument observed
Earth's geotail to study the distribution of hydrogen atoms in the antisunward
direction. The UVS measurements at H Lyman-Alpha are 16 times the
sensitivity of the EUV's (Extreme Ultraviolet Spectrometer). They will be
cross-compared with simultaneous measurements with EUV. The first geotail
observations were at 90 degrees cone and will slow slew from above to
equidistantly below the ecliptic plane at a slew rate of about 1 degree/minute
(290.82 microradians/second). The second observation is performed by a
slow slew about the antisunward directions (180 degrees or as close as
allowed to 180 degrees cone) to 160 degree cone angle in constant clock.
At 5:37 AM, the PPR (Photopolarimeter Radiometer) instrument made another
phase angle map of the lunar disk.
At 5:55 AM, the NIMS made its fourth full map mosaic, this time on
Mare Tranquillitatis with a range of phase angles of 118 to 111 degrees,
utilizing full map modes (204 wavelenghts, Gain state=1). The NIMS
resolution was at 194 km. The next NIM thermal map occurred at 8:22 AM with
the mosaic centered on the southern portion of Mare Tranquillitatis in the
proximity of Maskelyne crater north of the Apollo 11 landing site, with
phase angles from 107.5 degrees to 96 degrees. Three SSI frames were taken
using the clear filter.
At about 9 AM, lunar periapsis occurred with the spacecraft 74,150 miles
from the Moon. At 10:15 AM, the PPR made another lunar phase angle map.
At 10:19 AM, the PWS made a high resolution observation near Earth's
plasmsphere using the 80 kHz wideband mode. At 10:30 AM, the UVS made its
second measurment of Earth's geotail.
At 10:52 AM, NIMS made another thermal map mosaic, this time along
the terminator and the highland south of Rima Ariadaeus in Mare
Tranquillitatis. The SSI took two frames with the clear filter.
At 11:15 AM, at about 1 hours 20 minutes before ECA, the star scanner
shutter was closed and the spacecraft's attitude was based on the
gyroscopes only. The Magnetometer (MAG) was configured for calibration at
11:33 AM. The MAG will be operated in 6 of its 8 different configurations
during the Earth 1 encounter.
The PLS (Plasma) instrument was safed at 11:54 AM. At 12:03 PM with
the spacecraft now only 9,512 miles from Earth, the NIMS recorded some
mesopheric water profiles derived from the night side limb scans. Water
was observed in the tell-tale emissions in longspectrometer mdoe. One
scan was acquired near the equater over the Indian Ocean, another near the
70 N latitude near USSR/Scandinavia. The SSI simultaneously acquired
auroral imaging during the 70 N latitude scan with 5-10 km vertical
resolution.
At 12:14 PM, the SSI made lightning and aurora observations which
was recorded on the tape recoder. Communications was switched from
LGA-1 (Low Gain Antenna 1) to LGA-2. UVS observation was made at
12:23 AM of the night airglow morpology and altitude variations of NO
gamma (236.3 nm) and NO delta (198.0 nm) emissions. Altitudes started
at 1000 km and sampled down to the surface. The EUV made measurements to
search for emissions of H, He and O+ in the 50.0 to 125.0 region of the
spectrum starting in the exosphere on the nightside and ending in the
exosphere on the dayside.
At 12:30 PM, the DSN (Deep Space Network) lost contact with the
spacecraft as expected, as Galileo passed out of view of the tracking
stations. ECA occurred at 12:34:34 PM. At 12:38PM and 12:56PM, the NIMS
made two more mesopheric water profiles over the equator of the Pacific Ocean.
At 12:59 PM, the PWS made some more high resolution observations
of the near Earth plasmasphere. The PLS made observations of the
magnetosphere to determine the composition and source of the near Earth
solar wind, and to search for ion beams, charged oxygen, helium and
other heavy ions.
At 13:17 PM, the SSI took it first multispectral images of Australia
from the time it became visible near the terminator. The SSI will continue
to take images of Australia until it rotated out of view over the limb. These
images will be combine together to form an Earth feature track/zoom movie.
At 13:20 PM, the PPR measured the polarization at three separate
wavelengths on the day side of Earth. The resulting mosaic will
provide the best chance of observing both clouds and ocean surfaces.
At 13:33 PM, the NIMS made its first Moon observation since ECA,
centering across Sinus Medii east of the Murchison crater. The SSI
camera took two frames with the green filter.
The shutter of the star scanner was opened a 13:45 PM. At 14:04 PM
the HIC (Heavy Ion Counter) instrument was enabled to measure solar flares
and cosmic rays. The EUV was turned off.
At 14:16 PM, the NIMS obtained a Nyquist-sampled map of Australia and
its surrounding water to calibrate the NIMS longmap spectra as well as
to obtain spacial distributions of various mineralogical and vegetation
types. This map, the first of two Australia maps, concentrates on the
western half of Australia within 30 degress of the morning terminator with
spacial resolution of 35-50 km per nimsel. The SSI acquired 4-color maps
"on the fly" during each observation.
At 14:19 PM, the MAG starting taking measurements every 5 minutes
for about an hour to study the high freqency structure of Earth's bow
shock, which the spacecraft crossed multiple times.
At 14:34 PM, the PWS made observations using its 80 kHz wideband mode.
At 15:05 PM, the NIMS made its second Nyquist-sampled map of Australia, this
time concentrating on the eastern half some 60 degrees from the terminator.
At 15:34 PM, the UVS starting making UNEWS (UVS North East West South)
scans to provide a valuable set of control data for comparison with the
data acquired during the UVS NIMS Antarctica Map, as well as provide several
swaths of data regarding ozone abundance over the Antarctic. The North
South swath will start near the South Pole of Earth and will be compared
with the Equatorial swath and the 55 degree latitude swath that may be
be observed in the ozone emissions.
At 16:09 PM, the NIMS made its second lunar observation since ECA, and
eighth overall. The mosaic was centered on Sammering crater (lattide =
0.5 degrees, W longitude = 8 degrees) and east of the Apollo 14 and 12 landing
sites. Two SSI frames were taken with the clear filter.
At 16:59 PM, the NIMS now focused it attention on Antartica by taking
a Nyquist-sampled map of Antartic ice and it surrounding water. The SSI
acquired contigous 3-color maps with a spacial resolution of 85 km per pixel.
The second map was made by NIMS at 17:56 PM.
At 19:23 PM, the NIMS made its ninth lunar observation, this time on
northwest poing of Montes Riphaeus in Mare Insularum south of the Apollo
12 landing site. Using the long map mode with a phase angle of 56.4 degrees,
NIMS obtained it best lunar spectral map resolution (123 km). The SSI
obtained 4 frames with the clear filter.
At 19:44 PM, the NIMS obtained a lunar thermal map at 147 to 144 degrees
phase, over the Kastner crater in mare Smyhil. The NIMS resolution is at
about 274 km.
At 19:56 PM, the NIMS obtained its first Nyquist-sampled map for a Earth
global mosaic. Comprised of 12 OAPELS over some 25 hours, this map will
cover 30N to 30S near Africa at a spacial resolution of 125 km per pixel.
At 21:06 PM, the NIMS continued its Moon farside coverage by obtaining
a spectral map of Oceanus Procellarum between Euclides and Letronne craters
at a phase angle of 49 degree with 179 km resolution. The NIMS obtained
the Earth global moscaic #2 at 21:28 PM. Mosaic #3 came at 22:11 PM and
mosaic #4 at 23:48 PM.
At 23:34 PM, the NIMS made its 11th lunar observation on the area
of Hansteen and Billy craters in Oceanus Procellarum at a phase angle of 39.3
degrees with a resoltion of 188 km.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/14/90
Date: 14 Dec 90 19:25:13 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 14, 1990
As of noon (PST) Thursday, December 13, 1990, the Galileo spacecraft
is 2,328,560 miles from Earth and traveling at a heliocentric speed of
80,060 miles per hour; distance to the Sun is 89, 661,240 miles (0.97 AU).
The spacecraft is in all-spin configuration and spinning at 2.89 rpm. Round
trip light time is 0 minute, 22 seconds.
The Galileo spacecraft superbly completed its Earth flyby gravity assist
on December 8. Galileo's closest approach to Earth occurred at 12:34:34 PST
at an altitude of 597 miles; only 0.4 seconds late and 5 miles high with
respect to the target.
In preparation for the Earth 1 encounter, several commands were sent
primarily to configure the spacecraft's attitude control and power state
consistent with Earth flyby needs. On December 7, a NO-OP command was sent
to reset the command loss timer to 3 days. Other commands sent that day
included disabling the system sunpoint fault protection and attitude control
sun algorithms, Delayed Action Commands (DACs) to power cycle the RTG Boom
heaters off/on and several DACs to position the scan platform for NIMS (Near
Infrared Mapping Spectrometer) thermal control and to update Earth spin movie
scan platform pointing. Most of the DACs were executed on December 8 before
the Earth flyby; Earth spin movie updates were executed on December 11
and 12. About 20 minutes prior to closest approach, the PLS (Plasma)
instrument was also powered off, via DACs, to assure PLS thermal safety.
After the Earth flyby, commands were sent to configure the attitude
control subsystem and the system fault protection back to its pre-encounter
cruise state.
The LGA-1 (Low Gain Antenna 1) to LGA-2 antenna switch was successfully
performed from the stored sequence on December 8. The switch occurred about
20 minutes prior to Earth closest approach. The on-board switch command was
backed up by a real-time ground command about 1 minute after the on-board
switch.
The 21st RPM (Retro Propulsion Module) thruster flushing activity was
successfully completed December 9. Thruster temperature profiles were similar
to those observed on previous flushing activities.
A SITURN to lead the sun was successfully completed on December 10. The
turn, about 4 degrees, resulted in the spacecraft leading the sun about 2
degrees; another SITURN, about 6 degrees, was successfully performed on
December 13 and resulted in the spacecraft leading the sun by about 2.3
degrees. For both activities the spacecraft performance was normal and without
incident.
Subsequent to the SITURN on December 10, the sun gate fault protection
was re-enabled to provide protection from faults which could result in the
spacecraft being in a thermally unsafe off-sun attitude. After the Earth
flyby, the resulting trajectory will bring the spacecraft to 0.9 AU of the sun
on January 11, 1991.
An attitude control Target Motion Compensation (TMC) test was
successfully performed on December 10. Attitude control data was collected at
various clock and cone angles to assess the effectiveness of TMC. Analysis
of the data is in process and results will be used for the GASPRA encounter
in October 91.
Another set of Delayed Action Commands (DACs) were sent on December 12 to
cycle the radio frequency subsystem ranging channel off/on to improve
telecommunications link performance at 115.2 kbps and 7.68 kbps. The
commands will be executed by the spacecraft on December 14, 15, 16, and 17.
A non-interactive command was successfully sent to the EPD (Energetic
Particle Detector) on December 7 to put the instrument in its scan mode in
preparation for Earth encounter data collection.
Two non-interactive DACs were sent and executed on December 12 to lower
the HIC (Heavy Ion Counter) LET detector energy threshold and then return it
to its normal setting about 2 hours later. This command action was taken in
response to the Principal Investigators request after observing higher than
expected counts in the LET detector; later these higher counts were discovered
to be a normal characteristic of the detector.
Three non-interactive DACs were sent and executed on December 13 to the
DDS (Dust Detector) to increase its sensitivity. Action to lower the
instruments threshold was taken in response to noise signatures observed post
Earth flyby; these commands will properly configure the DDS for interplanetary
cruise.
A total of about 3400 photographs were successfully taken between
December 7 and December 13. About 1850 were taken within 36 hours of closest
approach and 1500 were taken for the spin movie on December 11 and 12. All
images were successfully returned except for 22 images of the spin movie,
namely, 10 contiguous frames in one segment (2 color filters) and 12
contiguous frames in another segment (2 color filters). The image data loss
experienced was expected due to known DSS (Deep Space Station) view period
constraints.
The AC and DC bus imbalance measurements remained relatively stable. The
AC measurement remained about 2 DN and now reads 45.6 volts. The DC
measurement varied about 30 DN from near 1 volt to 4.5 volts. All other
power-related measurements and spacecraft telemetry are normal.
The Project reviewed and approved the VE-14 cruise plan on December 13.
This sequence controls spacecraft activities from February 18 to April 29,
1991.
The no major problems were reported with GDS (Ground Data Systems)
operations in support of Earth Closest Approach (ECA) support. A better than
expected signal strength at switch from Low Gain Antenna 1 (LGA-1) to LGA-2
permitted 34 meter antenna and 26 meter antenna in Spain to continue to
acquire data for an additional 15 minutes through the end of track prior to
ECA. Prompt and measured response by DSN (Deep Space Network), NOCC (Network
Operations Control Center) and Station personnel to an alarm at the Australia
34 meter station early in the post ECA pass permitted continued data
acquisition with no loss of data.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 12/14/90
Date: 14 Dec 90 19:26:49 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 14, 1990
Yesterday, Galileo spacecraft successfully completed a UVS (Ultraviolet
Spectrometer) Lyman Alpha sky map. In addition to the UVS sky map, the NIMS
(Near Infrared Mapping Spectrometer) and PPR (Photopolarimter Radiometer)
instruments were powered off as planned and a No-Op command was sent to reset
the Command Loss Timer to 3 days,
Part I of the VE-12 (Venus-Earth 12) sequence memory uplink load was
initiated today at 9:00 A.M. PST. The uplink will take just over 2 hours to
complete. Part II of the VE-12 sequence will be uplinked on December 27.
Later today, Galileo will contunue taking images of Australia as part of
its planned Earth departure movie. Some science activity will continue on
Saturday, December 15 including final images of the Australian continent.
Earth encounter sequence activities will end on Saturday.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #3 - 12/14/90
Date: 14 Dec 90 23:39:50 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO MISSION STATUS
December 14, 1990
The Galileo spacecraft is 2.8 million miles from Earth, receding
at about half a million miles per day. At 89.3 million miles, it is
closer to the Sun than Earth is, and will continue approaching the Sun
on this orbit until January 11, when its present solar orbit will
carry it back outward, this time toward the Asteroid Belt. Present
orbital speed is almost 80,300 mph relative to the Sun.
Spacecraft health and mission performance continue to be
excellent. A sun-pointing maneuver was successfully completed
yesterday. Today the Deep Space Network is sending the first part of
the first post-Earth cruise sequence to the spacecraft. The current
sequence, which includes all the Earth-Moon scientific observations,
runs until Monday morning. The new sequence will control spacecraft
activities until mid-February 1991.
Scientific observations of the Earth-Moon system will be winding
up tomorrow, and the scientists are busy analyzing and interpreting
the results. They will give a first look at these results at a press
conference at 10 a.m. (PST) Wednesday, December 19, 1990, at JPL and
via the NASA SELECT satellite TV link.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo article
Date: 14 Dec 90 22:01:51 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Washington Times -- 12/14/90
"Galileo Pictures Far Side of Moon"
"Pictures by the Galileo spacecraft as it boomeranged past
Earth on its way to Jupiter show icy Antarctica and a giant
meteorite impact crater on the far side of the Moon."
The story reports that the last photos of the far side of the Moon
were made by the Apollo astronauts two decades ago and
quotes Galileo project scientist Torrence Johnson as saying
"this is the first time we've had a chance to use a spacecraft
designed to explore another planet to come back and look at our
own Earth and Moon as if we were alien observers."
The Times continues quoting Johnson, "In the process, we're
learning some new scientific things about our own world and
its companion, but perhaps more importantly, it's providing us
a different perspective on our home planet as a fragile world."
The story says that this past Saturday, Galileo swooped 597
miles above the southwest Atlantic Ocean, using Earth's
gravity as a slingshot to help expand the spacecraft's orbit
around the Sun so it can reach Jupiter in 1995. The paper says
that Galileo used Venus for the same purpose this previous
February and will fly by Earth again in December 1992.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.242 | GALILEO observed from Earth on its first pass | ADVAX::KLAES | All the Universe, or nothing! | Mon Dec 17 1990 20:07 | 24 |
| From: mike@sequoia.execu.com (Mike McCants)
Newsgroups: sci.space
Subject: Galileo Observed!
Date: 16 Dec 90 19:04:36 GMT
Organization: Execucom Systems Corp
Using a 32 inch telescope with a CCD camera attached, Paul Maley
obtained images of the Galileo spacecraft as it approached Earth the
evening before Earth encounter on December 8, 1990.
Galileo was first observed at 2:15UT, December 8, at a range of
376,000 miles. Galileo was observed for 1 and 1/2 hours. Paul
estimates that the magnitude of Galileo was about 16.5 to 17.
The observations were made under clear, Moonless skies from a site
about 80 miles southwest of Houston. Galileo was about 40 degrees up
in the southeast.
The Granat rocket canister, NORAD number 20354, was also observed at
apogee at a range of 119,000 miles.
Mike McCants
mike@execu.com
|
| 560.243 | GALILEO Update - December 17 | ADVAX::KLAES | All the Universe, or nothing! | Mon Dec 17 1990 20:46 | 30 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/17/90
Date: 17 Dec 90 21:00:24 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 17, 1990
The Galileo spacecraft successfully completed its Earth Encounter
sequence data taking activities on Saturday, December 15. Today, the
VE-12 (Venus-Earth 12) sequence went active. Later today, the
spacecraft will perform a scan platform calibration activity and a
SITURN to lead the sun. Tomorrow, the Trajection Correction Maneuver
Sequence TCM-9A will be sent to the spacecraft; maneuver execution
will be on Wednesday, December 19. The tenth occurrence of the CDS
(Command Data System) CRC 2A POR (Power-On Reset) Telemetry indication
was observed Saturday, December 15. The signature was identical to
the previous occurrences. Reset commands to clear the telemetry
indication will be sent later today; commands will be identical to
those used before.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.244 | GALILEO Update - December 18 | ADVAX::KLAES | All the Universe, or nothing! | Wed Dec 19 1990 16:29 | 32 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/18/90
Date: 18 Dec 90 20:48:15 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 18, 1990
Yesterday, the Galileo spacecraft successfully completed a
5-degree SITURN which resulted in the spacecraft leading the sun by
about 2.5 degrees. In addition to the SITURN, the scan platform
calibration activity was successfully performed.
Today, the sequence memory load for TCM-9A (Trajectory Correction
Maneuver) will be sent to the spacecraft. The TCM will be executed
tomorrow and it is designed to change the spacecraft's velocity by
about 5.3 m/sec.
The resetting of the CDS (Command Data Subsystem) critical
controller 2A POR (Power-On Reset) Telemetry indication will be
performed today. This action was reported erroneously as being
performed yesterday.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.245 | GALILEO Updates - December 19-20 | ADVAX::KLAES | All the Universe, or nothing! | Fri Dec 21 1990 20:00 | 124 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/19/90
Date: 19 Dec 90 18:58:44 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 19, 1990
Yesterday, the CDS (Command Data Subsystem) critical controller 2A POR
(Power-On Reset) Telemetry indication was successfully reset on the Galileo
spacecraft. Later that day, the TCM-9A (Trajectory Correction Maneuver)
memory load was successfully transmitted and received by the spacecraft.
Today, the TCM-9A will be executed; the first thruster burn pulse will
occur around 9 a.m. (PST). The maneuver is designed to impart a delta velocity
of about 5.3m/sec. Early tomorrow, a SITURN, to lead the sun, will be
performed.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/20/90
Date: 20 Dec 90 23:00:33 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 20, 1990
Yesterday, the Galileo spacecraft successfully executed the TCM-9A
(Trajectory Correction Maneuver) sequence. Spacecraft operation throughout
the activity was excellent and performance was near predicted levels.
Preliminary tracking data indicates an overburn of about 0.2 percent.
Today, the spacecraft successfully completed a 2.5-degree SITURN,
resulting in the spacecraft leading the sun by 1 degree.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo articles
Date: 20 Dec 90 23:32:42 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
The Washington Times --12/20/90 -- Pasadena, CA
Galileo's instruments performing perfectly
By Thomas D. Elias - Scripps Howard News Service
"NASA scientists reported yesterday that instruments aboard
America's Jupiter-bound Galileo spacecraft performed
perfectly on the probe's swift Dec. 8 fly-by of Earth.
The agency's Magellan probe, however, was providing
problems as one of its two tape recorders failed, producing
120-mile gaps in each 10,000 mile-long photo of Venus
surface. The gaps will be filled as the probe starts it second
pass over the planet, reported Elias.
Galileo, however, with flawless cameras, has produce an
Earth movie unrivaled by any earlier photos from space.
And still pictures of the moon's far side and unexplored
southern regions revealed new details, according to the story.
"This certified that our instruments are working better than
anticipated so we'll be ready for our encounter with the
asteroid Gaspara in 1992 and at Jupiter in 1995," said
University of Hawaii's Thomas McCord.
The article also reported good vehicle performance.
*********
The Washington Post -- 12/20/90 - Washington
Galileo Probe Reveals Giant Basin on Moon
By Kathy Sawyer
"Images from the itinerant spacecraft Galileo have revealed
the moon's largest known impact basin--a suspected but
never-before-seen dark region 1,200 miles across blasted
out by an asteroid-like object 100 miles across that slammed
into the moon, probably making it wobble and lurch."
The craft, launched 14 months ago zoomed past Earth and the
moon 11 days ago. "We don't see anything in the pictures
that would indicate intelligent life," JPL's Torrance V.
Johnson is quoted as saying. Scientists noted, however, that
Galileo was not equipped to detect life, according to the story.
Galileo's instruments did capture new data from inside
Earth's magnetic "tail, recorded lightning whistles, filmed
the first movie of Earth spinning in space and developed a
"key piece of data" required for study of ozone layer
depletion, wrote Sawyer.
The Post reported that Galileo's observations of the moon
provide more data for understanding its total global geology,
according to Brown University's James W. Head.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.246 | GALILEO Update - December 21 | ADVAX::KLAES | All the Universe, or nothing! | Wed Dec 26 1990 12:12 | 124 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/21/90
Date: 21 Dec 90 21:24:11 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
December 21, 1990
As of noon (PST) Thursday, December 20, 1990, the Galileo spacecraft
is 5,719,890 miles from Earth and traveling at a heliocentric speed of
81,560 miles per hour; distance to the Sun is 87,344,980 miles (0.94 AU).
Round trip light time is 0 minute, 58 seconds.
The Galileo spacecraft continued to successfully collect valuable
science data on December 14 and 15 as it rapidly receded from Earth.
The VE-11 (Venus-Earth) Earth encounter sequence was completed on
December 17.
The first part of the VE-12 sequence memory load was successfully
transmitted and received by the spacecraft on December 14. The VE-12
sequence went active on December 17 and controls spacecraft activities
to February 18, 1991.
Commands were sent on December 14 to properly configure the
attitude control telemetry map measurements in preparation for the
planned scan platform calibration activity (SCALPS) on December 18.
A NO-OP command was sent on December 14 to reset the Command Loss
Timer to 72 hours. Since the VE-12 sequence sets the command loss
timer to 240 hours, another NO-OP was sent on December 17, resetting
the timer to 240 hours.
Early on December 15, the tenth occurrence of the CDS (Command
Data Subsystem) Critical Controller 2A POR (Power-On Reset) telemetry
indication was observed; the last occurrence was noted on October 18.
All spacecraft telemetry indications were identical to those observed
for the previous nine events. Spacecraft performance was not impaired
as a result of this telemetry indication. On December 18, the
telemetry indicator was successfully reset via ground commands. The
commands were identical to those used on previous occasions; all CDS
hardware and software related functions were verified and are fully
functional.
A SITURN to lead the sun was successfully completed on December
17. The turn, about 5 degrees, resulted in the spacecraft leading the
sun by about 2.5 degrees. Another SITURN, about 2.5 degrees, was
performed on December 20 and resulted in a 1 degree Sun leading
attitude. Both SITURNs were completed without anomaly or incident.
A series of Delay Action Commands (DACs) were sent on December 14
to cycle the radio frequency ranging channel off/on to improve link
performance. All 9 of the DACs were properly executed by the
spacecraft between December 17 and December 20. Other commands were
sent on December 18 to configure the downlink telemetry rate to 1200
bps to assure acceptable link performance margin.
The TCM-9A (Trajectory Correction Maneuver) sequence memory load
was successfully transmitted and received by the spacecraft on
December 18. Prior to the execution of the maneuver the EPD (Energetic
Particles Detector) instrument was stepped to Sector O (the minimum
contamination location); after the maneuver was completed the EPD will
be repositioned to Sector 4 and powered off on December 21.
The maneuver activity was comprised of 5 burn segments using the
lateral thrusters only with benign duty cycle operation; the maneuver
was designed to impart a delta velocity of about 5.3 m/sec.
Spacecraft system performance throughout the maneuver was excellent.
RPM (Retro Propulsion Module) pressures and temperatures were well
within acceptable ranges and near predicted levels. After the first
three segments a sequence planned attitude pointing correction was
performed reducing the accumulated error from about 10 mrad down to
about 0.5 mrad. Following the last two segments a planned pointing
correction reduced the accumulated attitude pointing error from about
10 mrad to about 0.3 mrad. Spin rate corrections were required after
both the third and fifth burn segments. Preliminary radio tracking
data indicates the occurrence of slight overburn of about 0.2 percent.
The AC and DC bus imbalance measurement exhibited same activity.
The AC measurement varied abut 2 DN and now reads 46.5 volts. The DC
measurement increased about 35 DN and now reads near 9.3 volts. Very
little change was observed during the TCM activity. All other-power
related measurements and spacecraft telemetry are normal.
The Project Change Board approved a series of changes to the
spacecraft Flight Rules and the corresponding updates to the Ground
Software. The changes were in response to "lessons learned" during
operations and will enable more effective constraint checking during
the design and development of sequences. The software updates are
designated for completion as part of the delivery scheduled for April 1,
1991.
The Project is evaluating the impact of a proposal by the DSN
(Deep Space Network) to replace the elevation bearings at Spain 70
meter antenna during a 26 day period in June 1991.
On December 19, one hour of Galileo tracking time at Goldstone
was lost when the 70 meter antenna was stowed due to high winds. The
antenna stowing occurred after the completion of the VE-11 Earth
sequence and there was no significant impact to Galileo support. These
periodic high wind outages emphasize the Project requirement for redundant
tracking station support during the Io encounter in December 1995.
The December inputs to the System Engineer's Monthly Report
(SEMR) were provided on December 15. Current status of Project and
Institutional (FPSO/DSN) systems were provided. Excellent performance
was reported by all systems used to support the Earth 1 activities.
In addition, Gaspra and Earth 2 plans and schedules were provided with
the December SEMR inputs.
Last week it was reported that 3400 photographs were taken
between December 7 and December 13. The report should have read 2675
photographs. It is pointed out, however, that a total of 3410
photographs were taken by the SSI (Solid State Imaging) camera from
November 26 thru December 15.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.247 | Earth: The Motion Picture | ADVAX::KLAES | All the Universe, or nothing! | Thu Dec 27 1990 15:23 | 100 |
| From: clarinews@clarinet.com (WILLIAM HARWOOD, UPI Science Writer)
Newsgroups: clari.tw.space
Subject: Galileo movie of Earth released
Date: 19 Dec 90 21:20:46 GMT
A remarkable, first-of-a-kind movie shot by the Galileo probe
as it raced past Earth earlier this month shows the blue planet
spinning in the vast night of space, giving elated scientists a taste
of the view they can expect of Jupiter in 1995.
Captured by Galileo's state-of-the-art solid-state cameras,
the movie showed the blue-and-white Earth from a vantage point below
the planet, a view that included snowy white Antarctica and brownish
Australia that extended as far north as Florida and the Persian Gulf
region.
As the cloud-streaked planet rotated on its axis in the black
night of space, the glint of sunlight off oceans and rivers repeatedly
flared into view as entire continents rolled by as if on parade.
While Apollo-era photographs of the planet exhibit greater
sharpness in some instances, the Galileo movie marked the first time
humanity's home planet has been seen rotating on its axis. [Unless
you also want to count earlier weather satellite images of Earth's
rotation. - LK]
``The movie is unique in the sense it's from a single point
in...space and you see the Earth rotating,'' said Michael Belton,
Galileo imaging team leader. ``There have been no sequences of
pictures that show the Earth in motion.''
Galileo was launched Oct. 18, 1989, from the Space Shuttle
Atlantis on a convoluted trajectory requiring three gravity-assist
planetary flybys to boost the spacecraft on to a 1995 encounter with
distant Jupiter.
The nuclear-powered spacecraft whipped past Venus Feb. 9 and
completed the first of two Earth flybys Dec. 8 at an altitude of just
600 miles. The second Earth encounter, at an altitude of less than 200
miles, is set for Dec. 8, 1992, a velocity-boosting flyby that will
finally put Galileo on course for Jupiter.
The Earth movie was assembled by scientists at NASA's Jet
Propulsion Laboratory in Pasadena, using images taken by Galileo as
the robotic explorer raced past on Dec. 8.
As it approached and then receded, the $1.5 billion
spacecraft's instruments recorded more than 58 billion bits of data,
including more than 2,600 pictures of the Earth and Moon and priceless
data about the planet's space environment.
As an intellectual exercise, scientists studied the data for
evidence of life on Earth. While they were able to see clear signs of
biological activity, there was no direct evidence of intelligent life
in the Galileo data.
``The accumulated evidence we have from all the spectral data,
gas compositions and so forth, would give your hypothetical extra-
terrestrial explorer a very strong indication that you had biological
activity occurring on the Earth,'' said Galileo project scientist
Torrence Johnson.
``The question of intelligent life is more difficult. We don't
see anything obvious in the pictures that would indicate intelligent
life. Probably the best indication we have that there might be
something odd going on...is in the radio part of the spectrum.''
[If such aliens recognize life as we do. - LK]
During a news conference at JPL, Johnson described what an
alien scientist would be able to learn about Earth based on nothing
more than the flyby data from Galileo.
The alien, he said, would be able to determine the planet's
mass, diameter, density, and general composition from the Galileo data
and gain insights into the structure of Earth's crust. The alien also
would see large amounts of water, a few rocky continents, and one large
ice continent.
In addition, the composition of the atmosphere could be
determined, with levels of nitrous oxide, methane and oxygen
indicating the presence of biological activity on a large scale.
And the relative concentrations of various gases would imply the
presence of intelligent life in the process of altering its environment.
Johnson said scientists would use the Earth flybys to
fine-tune Galileo's instruments and ground-based techniques for the
upcoming encounter with Jupiter.
``We're using the Earth, basically, as an excellent testbed to
develop those capabilities,'' he said.
While the report card for the first Earth flyby is not yet in,
project manager William O'Neil said the encounter was ``essentially
perfect for us.''
``The spacecraft has done everything we asked it to do,'' he
said. ``It's just a great demonstration of what we have long been
planning to do at Jupiter.''
|
| 560.248 | | PAXVAX::MAIEWSKI | | Thu Dec 27 1990 20:56 | 4 |
| So I guess we have to wait 2 years for the 2nd fly-by to find out if
Earth has intelligent life. I'm betting that it does not.
George
|
| 560.249 | be optimistic | 2319::SAUTER | John Sauter | Fri Dec 28 1990 12:06 | 2 |
| Maybe by then it will.
John Sauter
|
| 560.250 | Intellegence?!? | 15372::LEPAGE | Life sucks then the bill comes in | Fri Dec 28 1990 14:36 | 13 |
| Re: Intelligent life on Earth
I have to disagree; I was fortunate (if you could call it that)
enough to visit Earth once. A particular species of arrogant simians
that that inhabit this planet consider themselves as intelligent but
they are far from it. The true intelligent life forms on Earth are the
Cetaceans but unfortunately they have been hunted nearly to extinction
by this arrogant simian species. In the long run, my money is on the
Terran cockroach for ultimately becoming the dominant intelligent life
form on this planet.
Drew
|
| 560.251 | | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Fri Dec 28 1990 15:27 | 20 |
| re .247
> While Apollo-era photographs of the planet exhibit greater
>sharpness in some instances, the Galileo movie marked the first time
>humanity's home planet has been seen rotating on its axis. [Unless
>you also want to count earlier weather satellite images of Earth's
>rotation. - LK]
Not really. Polar orbiting metsats are too low to give an image of
Earth's rotation, and synchronous metsats are of course orbiting with
the same angular velocity as the Earth.
There have been other missions which could have imaged the Earth in
this fashion, but I don't recall any doing so. We tend to explore near
Earth space with specialist spacecraft and instruments (and sometimes
ignoring data that we don't expect). The intersting aspect of
Galilieo's Earth encounters is the opportunity to examine Earth with
generalist instruments.
gary
|
| 560.252 | GALILEO Update - January 3 | ADVAX::KLAES | All the Universe, or nothing! | Tue Jan 08 1991 15:47 | 70 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/03/91
Date: 7 Jan 91 23:41:54 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 3, 1991
As of noon (PST) Thursday, January 3, 1991, the Galileo spacecraft is
12,634,280 miles from Earth and was traveling at a heliocentric speed of
83,480 miles per hour; distance to the Sun is 84,505,030 miles (0.92 AU).
Round trip light time is 2 minutes, 12 seconds.
Commands to reset the Command Loss Timer were sent on December 21, 27 and
January 2. The timer was reset to 240 hours, the planned value for this
mission phase.
A series of SITURNs, to lead the sun, were successfully performed on
December 22, 27, 31 and January 3. Spacecraft performance during all the
SITURNS was normal and without incident. The largest turn was 7 degrees on
December 27; the other three turns were about 3.5 degrees. The sun leading
attitudes after the turns varied between 1.7 and 3.2 degrees.
As planned, Part II of the VE-12 (Venus-Earth 12) sequence memory load
was successfully transmitted and received by the spacecraft on December 27.
This part of the sequence controls spacecraft activities from January 5 to
February 18.
The 23rd RPM (Retro Propulsion Module) thruster "flushing" activity was
successfully completed on January 2. All 10-N thrusters were "flushed" except
for the P thrusters which are used during SITURN activities. Spacecraft
performance during this activity was normal and the thermal profiles were
near previous levels.
A code change was made to MAG (Magnetometer) instrument's flight software
on January 2. The software change was made to preclude future data-related
anomalies similar to those noted in June 1990 MRO (Memory Readout) data where
the optimal averager operation caused a software stack overflow thereby
leading to corruption of MAG data.
The EUV (Extreme Ultraviolet Spectrometer) instrument was successfully
powered on January 3; all power and thermal profiles were normal. Cruise
science Memory Readouts (MROs) for the EUV, DDS (Dust Detector) and MAG
instruments were successfully performed on January 3.
About 45 minutes into the Australia 70 meter track on December 31, the
eleventh occurrence of the CDS (Command Data Subsystem) Critical Controller
2A POR (Power-On Reset) telemetry indication was observed; the last previous
occurrence was on December 15. All spacecraft telemetry indications were
identical to those observed for the previous ten events. Spacecraft
performance was not impaired as a result of this telemetry indication. On
January 3, the telemetry indicator was successfully reset via ground commands.
The commands were identical to those used on previous occasions; all CDS
hardware and software related functions were verified and are fully functional.
The AC/DC bus imbalance measurements exhibited some changes. The AC
measurement varied about 3 DN and now reads 46.5 volts; the DC measurement
continued to slowly increase. Over the last several weeks the DC measurement
bus gradually risen from near 3 volts to near 14 volts. All other
power-related measurements and spacecraft telemetry are normal.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.253 | GALILEO Update - January 7 | ADVAX::KLAES | All the Universe, or nothing! | Tue Jan 08 1991 19:55 | 33 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/07/91
Date: 8 Jan 91 16:33:18 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 7, 1991
Several activities are planned for the Galileo spacecraft today,
including:
o Cruise science Memory Readouts (MROs) for the EUV (Extreme Ultraviolet
Spectrometer), and MAG (Magnetometer), and DDS (Dust Detector)
instruments.
o Resetting the Command Loss Timer to 240 hours.
o A SITURN to lead Sun using the unbalanced turn capability for the first
time.
o Continued UVS (Ultraviolet Spectrometer) data collection.
Tomorrow, a CDS (Command Data Subsystem) "A" memory copy activity
is scheduled. This is a first time in-flight copy activity and
consists of copying the memory contents from CDS "A" elements prime
memory to extended memory.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.254 | GALILEO Update - January 9 | ADVAX::KLAES | All the Universe, or nothing! | Thu Jan 10 1991 16:48 | 25 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/09/91
Date: 9 Jan 91 20:02:57 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 9, 1991
Yesterday, the CDS-A memory copy activity was successfully
completed on the Galileo spacecraft without incident or anomaly.
Today, the telecommunications test will be performed for the radio
receiver and the command detector hardware elements for continued
characterization. Tomorrow, cruise science memory readouts, for the
EUV (Extreme Ultraviolet Spectrometer), MAG (Magnetometer) and DDS
(Dust Detector) and a SITURN to lead the sun are planned.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.255 | GALILEO Updates - January 8 and 10 | ADVAX::KLAES | All the Universe, or nothing! | Thu Jan 10 1991 19:11 | 63 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 01/08/91
Date: 9 Jan 91 00:52:55 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 8, 1991
The Galileo spacecraft is 15 million miles from Earth, and
84.12 million miles from the Sun. On Friday, January 11 it will be
at perihelion, at 84.10 million miles, and will never again come
so close to the Sun. Current speed in solar orbit is almost 84,000 mph.
Spacecraft health and mission performance are excellent.
The first post-Earth cruise sequence, which has been operational
since December 17 and continues until February 18, is presently
controlling Galileo spacecraft activities. This sequence included
the first post-Earth trajectory correction maneuver (December 19), as
well as continuing propulsion-system maintenance every few weeks
and more frequent sun-pointing turns.
Cruise science operations have resumed; Galileo's
magnetometer, dust detector and extreme UV instrument data are
being read out every few days.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/10/91
Date: 10 Jan 91 18:05:57 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 10, 1990
Yesterday, the planned periodically performed telecommunications tests
were successfully completed with the Galileo spacecraft. Earlier today, the
cruise science memory readouts for the EUV (Extreme Ultraviolet Spectrometer),
DDS (Dust Detector) and MAG (Magnetometer) instruments were successfully
completed. Additionally, a SITURN, of about 2 degrees, to lead the sun was
successfully completed.
At end of day today, the stored sequence will command a telemetry bit
rate change from 1200 bits/second to 40 bits/second, consistent with link
performance margin predictions. Tomorrow, Galileo will reach perihelion at
0.9 AU.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.256 | GALILEO Update - January 11 | ADVAX::KLAES | All the Universe, or nothing! | Mon Jan 14 1991 14:57 | 90 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/11/91
Date: 11 Jan 91 17:43:22 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 11, 1991
As of noon (PST) Thursday, January 10, 1991, the Galileo
spacecraft is 16,095,730 miles from Earth and traveling at a
heliocentric speed of 83,770 miles per hour; distance to the Sun is
84,093,720 miles (0.90 AU). Round trip light time is 2 minute, 50
seconds.
A command was successfully sent to reset the Command Loss Timer
on January 7. The timer was reset to 240 hours, the planned value for
this mission phase.
Two SITURN activities were successfully performed. The first
turn, on January 7, was performed using the unbalanced turn capability
with the Z1A and Z2A thrusters. The turn, about 7.2 degrees, resulted
in the spacecraft leading the sun by about 3.1 degrees. This is the
first time an unbalanced turn was performed. The unbalanced turn was
used to demonstrate this functional capability prior to its possible
use for TCM-9B (Trajectory Correction Maneuver 9B) in mid-March 1991.
The second SITURN, about 1.8 degrees resulted in the spacecraft
leading the sun by about 3 degrees, was performed on January 10 and
used the usual P-thrusters. Spacecraft performance during both of the
SITURNs was normal and without incident.
Cruise Science Memory Readouts (MROs) were successfully performed
for the EUV (Extreme Ultraviolet Spectrometer), DDS (Dust Detector)
and MAG (Magnetometer) instruments on January 7 and 10.
Several telecommunications-related tests were successfully
completed on January 9 and 10. Tests were performed to collect data
for continued trend analysis characterizing the radio receiver
Automatic Gain Control (AGC) and command tracking loop capacitor
performances. In addition to the RF tests, a Command Detector Unit
(CDU) signal-to-noise performance test was completed.
The CDS-A (Command Data Subsystem) memory copy activity was
successfully performed on January 8. This activity demonstrated the
first in-flight use of the CDS copy capability. Completing this
activity is the first step in loading the entire CDS extended memory;
CDS-B memory copy is scheduled to be performed on January 17. For
this "A" copy activity the memory contents of CDS-A elements (HLM1A,
LLM1A, LLM2A, DBUM1A&1B, BUM1A) was copied from prime memory into the
extended memory. Spot-check memory readouts were subsequently
performed and indicated no parity errors or anomalies. Once the
entire memory is copied into extended memory (192K words) and
verified, the time to recover from a future possible chip/location
failure will be reduced.
Beginning on January 10, changes in Sun-spacecraft-Earth geometry
required the downlink transmission data rate be reduced from 1200 bps
to 40 bps to ensure acceptable data quality. The data rate change was
pre-planned and was commanded from the stored sequence. Between
January 10 and end of day January 14 intermittent 1200 bps operation
is planned, however after January 14 the data rate will remain at 40
bps until early April 1991.
The AC/DC bus imbalance measurements exhibited some change. The
AC measurement dropped about 4 DN and now reads 45.8; the DC bus
measurement remained quite steady and reads near 13.5 volts. All
other power-related measurements and spacecraft telemetry are normal.
Today, the spacecraft will reach perihelion at 0.90 AU. From
this point on, the spacecraft will recede from the sun as it travels
toward an encounter with the asteroid Gaspra in late October 1991
prior to its planned second Earth flyby in December 1992.
A Galileo tracking pass was cancelled on January 8 when the
Goldstone 70 meter station declared that their S-band Masers were not
able to support the activity. The pass had been scheduled for two
hours and 45 minutes. There was no spacecraft activity planned during
this period thus no additional support was requested. The antenna was
also scheduled to start on January 8 to permit elevation bearing load
balancing and other maintenance activities. The 70 meter antenna is
scheduled to return to service on February 1.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.257 | GALILEO Update - January 14 | ADVAX::KLAES | All the Universe, or nothing! | Mon Jan 14 1991 18:04 | 46 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/14/91
Date: 14 Jan 91 17:44:38 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 14, 1991
The health of the Galileo spacecraft continues to be excellent. The
spacecraft status is as follows:
o System Power Margin - 43 watts
o Spin Configuration - Dual Spin - cruise mode
o Spin Rate/Sensor - 3.15 rpm/star scanner
o Spacecraft Attitude Sun Point Angle - 2.8 degrees
plus or minus 0.3 degree (leading)
o Downlink telemetry rate/antenna - 1200 bps
(uncoded)/LGA-2 (Low Gain Antenna 2)
o General Thermal Control - all temperatures within acceptable range
o RPM (Retro Propulsion Module) Tank Pressures - all within acceptable
range
o Orbiter Science- all powered off except HIC (Heavy Ion Counter), DDS
(Dust Detector), MAG (Magnetometer), EUV (Extreme Ultraviolet
Spectrometer) and UVS (Ultraviolet Spectrometer)
o Probe/RRH (Radio Relay Hardware) - powered off, temperatures nominal
o Command Loss Timer Setting - 240 hours
Today, spacecraft planned activities include:
o Cruise science memory readouts for the EUV, MAG and DDS instruments.
o Continued collection of UVS data.
o A SITURN to lead the sun.
o A downlink data rate change from 1200 bps to 40 bps
(uncoded) consistent with link performance predictions.
No spacecraft activities are planned for tomorrow, January 15.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.258 | GALILEO Updates - January 15-16 | ADVAX::KLAES | All the Universe, or nothing! | Thu Jan 17 1991 16:35 | 50 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/15/91
Date: 15 Jan 91 19:32:20 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 15, 1991
Yesterday's SITURN, cruise science memory readout and downlink rate
change to 40 bps were all successful with the Galileo spacecraft. Today,
there are no spacecraft activities planned. Tomorrow, the spacecraft will
be commanded from dual-spin to all-spin operations due to the lack of valid
star sets and remain in the all-spin mode until February 25.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/16/91
Date: 16 Jan 91 22:22:55 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 16, 1991
Today, the Galileo spacecraft will be commanded to all-spin mode
operation due to the lack of valid star sets at required flight attitudes
until February 25. While in the all-spin mode, the spacecraft will perform
sun acquisitions to maintain sun point for thermal control reasons.
Tomorrow, the CDS (Command Data Subsystem) "B" memory copy activity is
planned. This activity will copy the contents of the CDS "B" prime memory
into the extended memory using the same process successfully performed last
week for the CDS "A" copy activity.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.259 | GALILEO studies of Earth's Moon (Part 1) | ADVAX::KLAES | All the Universe, or nothing! | Thu Jan 17 1991 16:45 | 104 |
| From: lvron@saturn.lerc.nasa.gov (Ronald E. Graham)
Newsgroups: sci.space
Subject: Galileo's flyby sheds light on lunar mystery
Date: 14 Jan 91 18:36:48 GMT
Organization: NASA Lewis Research Center
[The following article was published in the Cleveland Plain Dealer, 01/13/91.
It was written by Ron Haybron, associate professor of physics at Cleveland
State, in his weekly "Science Notebook." - RG]
In these tight-money days, scientists are careful to capitalize on every
opportunity to gather any scrap of data that becomes available. For instance,
they got a chance to snatch a glance at the back side of the Moon last month
as the Galileo spacecraft whizzed by on its long voyage to Jupiter.
That Galileo came anywhere near the moon on this trip was strictly an accident:
its objective is to investigate Jupiter and some of its satellites, starting
in December 1995. But a series of events that began with the loss of the
space shuttle Challenger culminated in the close encounter in December [1990],
which produced some welcome information about our nearest planetary neighbor.
The spacecraft, which carries an orbiter for a prolonged imaging mission and a
probe that will parachute into the Jovian atmosphere to monitor conditions
there, was carried into an orbit above the Earth's atmosphere by the shuttle
Atlantis, from which it was launched. In the original plan, the rocket to
propel Galileo toward Jupiter was the Centaur, a LH_2/LO_2-powered "upper
stage" that was developed at NASA Lewis Research Center.
This powerful engine was originally designed to be put atop a primary booster,
such as the Atlas, to carry heavy interplanetary probes, such as the Voyager
spacecraft, from low Earth orbit to their distant goal. And it seemed perfect
for Galileo.
But after the Challenger accident, planners at the Johnson Space Center in
Texas decided that putting the Centaur in the cargo bay of a shuttle was too
risky. The rocket had not been planned for use on missions with a crew, and
even though the Lewis launch team had acquired a lot of experience with
Centaur and was confident it could do the job safely [Amen. I was there.],
Centaur was replaced with a lower-powered solid-fuel rocket. Such devices
are basically large-scale versions of Fourth of July bottle rockets. They
are considered much safer than liquid-fueled engines.
Once that decision had been made, the short, fast trajectory to Jupiter that
had been possible for Galileo when driven by the powerful centaur was now
impossible. Instead, planners had to come up with a very complex mission
profile involving several flybys of various bodies in the inner part of the
solar system.
This was necessary to take advantage of the "slingshot effect," in which a
spacecraft flies very near a moon or planet, speeds up as it falls toward the
larger body, and flies off at a greater speed than it had before the encounter.
Such a result, at first glance, seems to violate conservation of energy, but
in fact the large body slows down slightly. The slingshot effect has become
a routine way of flinging low-powered spacecraft off to the outer reaches of
the solar system, but the path for such a maneuver is very long, so such
missions are considerably extended, subjecting the spacecraft to prolonged
exposure to the hostile environment of space and thus an increased risk of
damage by radiation or by tiny meteoroids.
Among multiple "loops" around the Sun, Venus, and Earth, Galileo passed very
close to the back side of the Moon, providing an opportunity to take a look
at that seldom-seen region with the modern imaging tools carried by the
spacecraft. Researchers hope they can learn more about the composition of
the Moon's far side from this data.
This interest is actually a continuation of the work begun in the 1960s with
the Apollo landings on the lunar surface. Although many regard these brave
accomplishments as primarily political, some prominent members of the science
community gave the enterprise vigorous support as a way to learn about the
Moon's origins.
How the Moon was formed has been a controversial topic almost since French
astronomer and mathematician Pierre Simone de Laplace [Laplace transforms]
proposed at the end of the 18th century his condensation theory of the
formation of the solar system.
In this picture, the planets "condensed" from a primordial cloud of gas and
dust that surrounded the newly-formed Sun. In the swirling mess, particles
collided and stuck to form larger pieces, then chunks, then bigger chunks,
and finally the planets as we see them today.
This explanation for the formation of the planets, including Earth, seems
just as suited to the Moon. Isn't it likely that the Moon formed at the
same time as the Earth and by the same mechanisms? The data available even
before Apollo and the lunar samples returned by Soviet robot probes in the
1960s belied this notion. The Moon is less dense than Earth and has a
different chemical composition.
To explain these differences, some theorists proposed that the Moon had formed
in a different part of the pre-planetary nebula, at a different distance from
the Sun, where the chemical composition [of the nebula?] would be different.
Then it was somehow captured by the Earth. The catch with this picture was
finding a way to model the complicated encounters needed for the capture.
A third explanation was that early on, Earth broke into two pieces, with the
Moon originally a piece of the low-density outer crust of the Earth. This
was the popular theory when I was a student - that the cavity occupied by
the Pacific Ocean was the hole left by stuff that became the Moon.
The Apollo data led to a new vision, that the Moon was formed when the young
Earth was hit by a giant meteoroid. We will continue this "Moon-mystery"
discussion next week.
|
| 560.260 | GALILEO Update - January 17 | ADVAX::KLAES | All the Universe, or nothing! | Thu Jan 17 1991 22:30 | 31 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.astro,sci.space
Subject: Galileo Update - 01/17/91
Date: 17 Jan 91 18:14:06 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 17, 1991
Yesterday, the Galileo spacecraft's operating mode was
successfully changed from dual-spin to all-spin followed by a planned
Sun acquisition to maintain the required Sun pointed attitude for
thermal control reasons.
Today, the CDS "B" (Command Data Subsystem) memory activity is in
process. This activity is similar to that successfully performed last
week for the CDS "A" copy activity.
Tomorrow, Spacecraft activity will include a sun acquisition
activity and cruise science memory readouts for the EUV (Extreme
Ultraviolet Spectrometer), MAG (Magnetometer) and DDS (Dust Detector)
instruments.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.261 | GALILEO Update - January 17 (#2) | ADVAX::KLAES | All the Universe, or nothing! | Fri Jan 18 1991 13:24 | 101 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 01/17/91
Date: 17 Jan 91 23:37:20 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 17, 1991
As of noon (PST) Thursday, January 17, 1991, the Galileo
spacecraft is 19,464,250 miles from Earth and traveling at a
heliocentric speed of 83,560 miles per hour; distance to the Sun is
84,388,010 miles (0.90 AU). Round trip light time is 3 minutes, 26
seconds.
A command was successfully sent on January 14 to reset the Command
Loss Timer to 240 hours, the planned value for this mission phase.
Cruise Science Memory Readouts (MROs) were successfully completed
on January 14 for the EUV (Extreme Ultraviolet Spectrometer), DDS
(Dust Detector) and MAG (Magnetometer) science instruments.
A SITURN to lead the sun was successfully performed on January
14. The turn, about 4.8 degrees, resulted in the spacecraft leading
the sun by about 2.5 degrees. Spacecraft performance during the
activity was normal with no anomalies/incidents observed.
A series of Delay Action Commands (DACs) were sent on January 11
to cycle the PLS (Plasma) instrument's replacement and supplemental
electrical heaters off/on, respectively. This action was requested to
better characterize the thermal behavior of the PLS. It was observed
during the Earth 1 flyby that the PLS experienced temperatures
somewhat higher than anticipated; at no time, however, was the health
and safety of the instrument at risk. The PLS replacement heater was
powered off and its supplemental heater activated on January 11 via
DACs. DACs to reverse the heater configuration will be executed on
January 18 after sufficient thermal data is collected.
The CDS "B" (Commmand Data Subsystem) memory copy activity was
successfully performed on January 17. This activity demonstrated the
second in-flight use of the CDS copy capability. For this "B" copy
activity the memory contents of CDS "B" elements (HLM1B, LLM1B, LLM2B,
BUM1B) was copied from prime memory into the extended memory.
Spot-check memory readouts were subsequently performed and indicated
no parity errors or anomalies. This activity completes the total copy
of the CDS prime memory into the extended memory and consequently
reduces the time to recover from a future possible chip/location
failure. Later in January a more complete CDS memory readout will be
performed for both CDS "A" and "B" sides.
Commands to reduce the downlink data rate from 1200 bps to 40 bps
uncoded data were executed from the stored sequence on January 14.
The data rate reduction is necessary until early April 1991 to ensure
acceptable data quality. The data rate change occurred, as planned,
and data was successfully processed by the Ground Data System (GDS)
without anomaly or incident.
The spacecraft reached perihelion at 0.9 AU on January 11;
thermal profiles were near expected levels and no anomalies/incidents
were observed. From this point on, the spacecraft will recede from the
sun as it travels toward an encounter with asteroid Gaspra (about 2.1
AU) in late October 1991 prior to its planned second Earth flyby in
December 1992.
Due to the lack of valid star sets and required attitude
constraints between January 16 and February 25, the spacecraft's
operating mode was changed from the dual-spin mode to the all-spin
mode. In the all-spin mode, the spacecraft will be commanded via the
stored sequence to perform sun acquisitions about every two days to
maintain the tight sun point attitude constraint necessary for thermal
safety.
The spacecraft has operated previously in the all-spin mode for
extended time periods without anomaly or incident. The first time was
between launch and the first dual-spin transition (about L + 15 days),
and the other about 20 days in response to spacecraft safing execution
in January 90. In spacecraft safing, unlike those commanded from
sequence, sun acquisitions were performed automatically every 12 hours
from the sun point fault protection algorithm.
The AC/DC bus imbalance measurements exhibited some activity.
The AC measurement increased about 2 DN and now reads 46.6 volts. The
DC bus measurement increased about 4 DN and now reads 13.9 volts. No
significant changes were observed in either measurements when going
from dual-spin to all-spin operation. All other power-related
measurements and spacecraft telemetry are normal.
The GDS test program for the German Space Operations Center
(GSOC) Cruise Science operations support in September has started.
GSOC internal testing of their telemetry system has been in process
since early January. Command System testing is scheduled to start
next week.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.262 | GALILEO Update - January 18 | ADVAX::KLAES | All the Universe, or nothing! | Fri Jan 18 1991 20:27 | 50 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/18/91
Date: 18 Jan 91 18:57:30 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 18, 1991
The status of the Galileo spacecraft as of end of day January 17 is as
follows:
o System Power Margin - 66 watts
o Spin Configuration - All-Spin - cruise mode
o Spin Rate/Sensor - 2.89rpm/star scanner
o Spacecraft Attitude Sun Point Angle - approximately
1.7 degrees plus or minus 0.3 degree
o Downlink telemetry rate/antenna - 40 bps
(uncoded)/LGA-2 (Low Gain Antenna)
o General Thermal Control - all temperatures within
acceptable range
o RPM (Retro Propulsion Module) Tank Pressures - all
within acceptable range
Yesterday on the Galileo spacecraft, the CDS "B" (Command Data
Subsystem) memory copy activity was successfully completed; spot-check
memory readouts indicated no anomalies or parity errors.
Today, cruise science memory readouts were completed for the EUV
(Extreme Ultraviolet Spectrometer), MAG (Magnetometer) and DDS (Dust
Detector) instruments. In addition to the science readouts, a planned
sun acquisition was successfully completed.
A total of 2950 real-time commands have been transmitted to
Galileo. Of these, 1557 have been pre-planned in the sequence design
and 1393 were not. In the past week, a total of 149 real time commands
were sent; 141 were preplanned and 8 were unplanned.
Over the coming weekend, spacecraft activity will be limited to a
planned radio science calibration on Saturday and a sun acquisition on
Sunday.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.263 | GALILEO Update - January 21 | ADVAX::KLAES | All the Universe, or nothing! | Mon Jan 21 1991 18:43 | 28 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/21/91
Date: 21 Jan 91 18:40:41 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 21, 1991
Today, commands were sent to the Galileo spacecraft to reset the
Command Loss Timer and to modify the system fault protection state in
preparation for the planned Low Gain Antenna switch next week. Later
today, the spacecraft will perform a planned sun acquisition and a
cruise science memory readout activity for the MAG (Magnetometer) and
DDS (Dust Detector) instruments.
Tomorrow, a CDS "A" (Command Data Subsystem) memory readout
activity is scheduled. This readout will provide memory verification
subsequent to the memory copy performed on January 8.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.264 | GALILEO Update - January 22 | ADVAX::KLAES | All the Universe, or nothing! | Tue Jan 22 1991 19:10 | 27 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/22/91
Date: 22 Jan 91 18:53:00 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 22, 1991
Yesterday's activities on the Galileo spacecraft were all
successfully completed. The Sun acquisition activity and science
memory readout for the DDS (Dust Detector) and MAG (Magnetometer)
instruments were performed as planned.
Today, the planned CDS "A" (Command Data Subsystem) memory
readout activity is in process and proceeding well. Tomorrow, another
of the stored sequence periodic Sun acquisitions will be performed to
maintain Sun point attitude.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.265 | GALILEO Update - January 23 | ADVAX::KLAES | All the Universe, or nothing! | Wed Jan 23 1991 19:04 | 28 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/23/91
Date: 23 Jan 91 18:48:51 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 23, 1991
Yesterday, the CDS "A" (Command Data Subsystem) prime and
extended memory readout was successfully completed on the Galileo
spacecraft; no anomalies or parity errors were observed.
Today, a Sun acquisition will be performed to maintain the
required thermally safe Sun pointed attitude. This will be the fifth
Sun acquisition since going to all-spin operation on January 16.
No spacecraft activity is planned for tomorrow, but a command
will be sent to reset the Command Loss Timer to 144 hours.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.266 | GALILEO Update - January 24 | ADVAX::KLAES | All the Universe, or nothing! | Thu Jan 24 1991 19:33 | 33 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/24/91
Date: 24 Jan 91 18:46:36 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 24, 1991
Yesterday, the planned sun acquisition was successfully completed
on the Galileo spacecraft. Today, no spacecraft activity is planned.
A command was successfully sent to reset the Command Loss Timer.
Tomorrow, spacecraft operations will consist of periodically
performed activities including:
o A sun acquisition (SITURN)
o A MAG (Magnetometer) and DDS (Dust Detector) cruise
science memory readout, and
o RPM (Retro Propulsion Module) thruster maintenance
It was reported yesterday that two more than the expected number
of lock indications were observed in CDS (Command Data Subsystem)
telemetry on January 22; an investigation is in process.
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |
|
| 560.267 | GALILEO Update - January 24 (#2-3) | ADVAX::KLAES | All the Universe, or nothing! | Fri Jan 25 1991 21:09 | 108 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 01/24/91
Date: 25 Jan 91 00:47:57 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 24, 1992
As of noon (PST) Thursday, January 24, 1991, the Galileo spacecraft is
22,659,670 miles from Earth and traveling at a heliocentric speed of
82,880 miles per hour; distance to the Sun is 85, 374,930 miles (0.91 AU).
Round trip light time is 4 minutes, 0 seconds.
A command was successfully sent on January 21 to set the Command Loss
Timer to its new value of 144 hours in preparation for the LGA-2 (Low Gain
Antenna-2) to LGA-1 antenna switch on January 31. A separate command was
also sent on January 21 to modify the system fault protection state to select
LGA-1. Another command to reset the Command Loss Timer to 144 hours was sent,
as planned, on January 24.
Cruise Science Memory Readouts (MROs) were successfully completed on
January 19 for the EUV (Extreme Ultraviolet Spectrometer), DDS (Dust Detector)
and MAG (Magnetometer) science instruments; MROs for the DDS and MAG were also
performed on January 21.
Two USO (Ultra Stable Oscillator) calibration tests were successfully
completed on January 19 and 21. These tests provide trend information to
characterize this ultra-stable downlink frequency source.
A total of four sun acquisition activities were successfully performed;
the sun acquisitions were performed, as planned, on January 18, 20, 21 and
23 to maintain a thermally safe sun pointed attitude. To date four sun
acquisitions out of the 17 planned in VE-12 (Venus Earth-12) have been
completed. Following each sun acquisition activity, star buffer memory
readouts were succesfully completed. These readouts provide valuable star
intensity information data which is being used to update the attitude control
star catalog.
The CDS A (Command Data Subsystem) prime and extended memory was
successfully read out on January 22; no parity errors were observed with the
memory readout. The CDS B memory readout is planned for January 30. At the
end of the planned uplink for the CDS "A" memory readout activity, the number
of command lock change indications observed in both CDS A and B was two more
than expected (62 vs. 60). This is second occurrence using the 70 meter
station in Australia and third occurrence overall. The first occurence was
on September 13, 1990. The second occurrence at the 70 meter Goldstone station
on November 7, 1990 and resulted from a CPA (Command Processor Assembly)
hardware failure. There was no indication of any abnormal spacecraft operation
as a result of any of these indications. The spacecraft continues to properly
receive and process all commands. Investigation of these unexplained
indications is in process.
The AC/DC bus imbalance measurements exhibited some minor activity. The
AC measurement dropped about 1 DN and now reads 46.4 volts. The DC bus
measurement dropped about 20 DN and now reads 11.6 volts; the DC measurement
reduction occurred during a period of no spacecraft activity. All other
power-related measurements and spacecraft telemetry are normal.
The Project reviewed and approved the final profile design for the VE-14
sequence on January 22, 1990. The VE-14 sequence controls spacecraft
activities from February 18 to April 29, 1990.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #3 - 01/24/91
Date: 25 Jan 91 00:49:31 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 24, 1991
The Galileo spacecraft is about 22.7 million miles from
Earth, and its speed in solar orbit is 82,880 mph. It has flown
nearly 736 million miles since launch in October 1989, and has
1.6 billion miles to go before reaching Jupiter in December 1995.
Round-trip communication time is just over 4 minutes.
Spacecraft health and mission performance continue to be
excellent. Galileo is now in the all-spin mode as it was in its
first two weeks of flight, rotating at about 2.9 rpm and
routinely turning to re-point the spin axis at the Sun about
every other day. It is also routinely collecting data on
interplanetary dust and magnetic fields.
On Thursday, January 31, the spacecraft will switch Earth
communications from its second Low Gain Antenna, mounted on the
shady side of the spacecraft, to the primary Low Gain Antenna
mounted at the peak of the sunny side. This is because Galileo
will cross Earth's orbit in three weeks, and the spacecraft-Earth
geometry is changing and moving Earth into that antenna's pattern.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.268 | GALILEO Update - January 25 | ADVAX::KLAES | All the Universe, or nothing! | Mon Jan 28 1991 18:00 | 44 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/25/91
Date: 26 Jan 91 00:00:38 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 25, 1991
The status of the Galileo spacecraft status as of end of day
January 24 was as follows:
o System Power Margin - 69 watts
o Spin Configuration - All-Spin - cruise mode
o Spin Rate/Sensor - 2.89rpm/star scanner
o Spacecraft Attitude Sun Point Angle - approximately
1.5 degrees plus or minus 0.3 degree
o Downlink telemetry rate/antenna - 40 bits/second
(uncoded)/LGA-2 (Low Gain Antenna-2)
o General Thermal Control - all temperatures within
acceptable range
o RPM (Retro Propulsion Module) Tank Pressures - all
within acceptable range
Today, the spacecraft successfully completed the planned sun
acquisition and RPM maintenance activities. Later today a cruise
science memory readout will be performed for the MAG (Magnetometer)
and DDS (Dust Detector) instruments. Weekend operations will be
limited to a routine USO (Ultra Stable Oscillator) characterization
test on Saturday and a planned Sun acquisition on Sunday.
A total of 3080 real-time commands have been transmitted to
Galileo. Of these, 1687 have been pre-planned in the sequence design
and 1393 were not. In the past week, a total of 130 real-time
commands were sent; all were pre-planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.269 | GALILEO Update - January 28 | ADVAX::KLAES | All the Universe, or nothing! | Mon Jan 28 1991 18:53 | 33 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/28/91
Date: 28 Jan 91 18:39:14 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 28, 1991
Over the weekend both the USO (Ultra Stable Oscillator) and the
sun acquisition activities were performed successfully with the
Galileo spacecraft. However, two unexpected lock change telemetry
indications were observed at the start of yesterday's tracking pass
with the Canberra 70 meter station. At the end of tracking pass on
January 26, all spacecraft telemetry was normal.
These latest unexpected indications are in addition to those
observed on January 22, and have caused no abnormal operation.
Galileo continues to properly receive and process all commands.
Today, a command was sent to reset the Command Loss Timer and a
cruise science memory readout for the DDS (Dust Detector) and MAG
(Magnetometer) was successfully performed. Tomorrow, another sun
acquisition activity is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.270 | Part 2 of article in 560.259 | ADVAX::KLAES | All the Universe, or nothing! | Tue Jan 29 1991 14:11 | 104 |
| From: lvron@saturn.lerc.nasa.gov (Ronald E. Graham)
Newsgroups: sci.space
Subject: The Moon (continuation of Galileo article)
Date: 28 Jan 91 19:34:41 GMT
Organization: NASA Lewis Research Center
[This is the second part of the article that appeared in the Cleveland Plain
Dealer: the first part I posted last week. It was written by Cleveland
State physics prof Ron Haybron. I dedicate the postings to Gary Coffman,
ke4zv.UUCP, who told this newsgroup I had an "unscientific attitude" and
never apologized for saying it. Pbbbpthth! - RG]
To some, the Moon is cruel. When Juliet expresses her concern that Romeo
was not sincere in his love, he swears it on the Moon. To which Juliet
replies:
Oh, swear not by the moon, the inconstant moon,
...That monthly changes in her circled orb.
Of course, she was referring to the Moon's changing appearance, fearing that
Romeo's love might prove to be just as variable. But her complaint might be
taken up by an assortment of scientists throughout history, who have worked
vainly to learn where our "sister planer" originated.
One of the most prominent in this chain of disappointed savants was chemist
and Nobel Prize winner Harold C. Urey (1893-1981), who spent the last 40
years of his career seeking to understand how the Earth and Moon came to be.
He stimulated scientific research into the origins of the solar system during
that period, most notably through his influence in mounting the Apollo missions
to the Moon.
In particular, Urey believed the Moon to be a primordial body, formed at the
birth of the solar system ~4.6 billion years ago, then captured by the Earth
in a close encounter, and essentially unchanged since then. Since the oldest
Earth rocks yet found are [considered] less than ~4 billion years old, and
because the surface of the Moon is not subjected to the erosive changes of
wind and water, studies of it could yield information unavailable on Earth.
However the Moon came to be, its formation had to be a part of the larger
chain of events that formed the entire solar system. The generally accepted
scenario for this process follows. (It should be noted that even when the
broad outlines of such a story are commonly agreed upon by the experts, many
details remain in dispute. These stories of the origins of the stars and
planets are fleshed out be predictions of computer models, which require
simplifying assumptions to be feasible [Amen!], and specifics differ from
one calculation to another.)
The entire assemblage started as a slowly-rotating mass of gas and dust.
This cloud was mostly hydrogen, but it was laced with heavier elements that
had been synthesized in the energy cycle of earlier, deceased stars. Dis-
turbed by some external agent, perhaps the explosion of a nearby aging,
giant star, the cloud began to contract due to self-gravity.
A lot of the matter collapsed to the center, to form the great ball that
would become the Sun. Much of the rest collected in a flattened disc, called
the "solar nebula," in which the constituent atoms and molecules of gas and
particles of cosmic dust revolved about the forming star.
As the nebula continued to contract from a spherical glob to a thin disc, it
heated up due to gravitational compression. Solids vaporized. Meanwhile,
the Sun winked on, its center heated so much by gravitational compression that
fusion of hydrogen nuclei (protons) began. This kept the nebular disc hotter
near the Sun than in its outer reaches. It began to cool differentially.
Rock-forming materials, minerals and metals began to condense into particles
in the region near the Sun, while the lightest and most volatile materials
remained in the gaseous state and were "flushed out." Only in the outer
reaches of the nebula did these volatiles become ices of water, methane, and
ammonia.
This would account for the fact that the inner planets - Mercury, Venus,
Earth, and Mars - are dense and rocky, whereas the outer planers, starting
with Jupiter, contain much of the original hydrogen and are far less dense.
Saturn is even less dense than water.
As the nebula evolved, tiny particles came together, forming bigger ones,
which grew into even larger bodies, called planetesimals. These in turn
collided with each other to finally become planets. In the final phase of
this process, the forming planets, especially the big outer planets, were
massive enough to deflect some planetesimals with their gravity and fling
them to other parts of the solar system. Scientists believe that is where
our water and some other volatile materials came from.
With this background, the Moon's origin seems obvious: it must have formed
as a system with Earth, by the same mechanisms. But the chemistry of the
Moon doesn't fit that explanation. Compared to Earth, it is poor in metals
like iron. Chemically, it closely resembles the rocks in the crust and
mantle of the Earth, deprived of volatiles such as water.
Other chemical similarities between Earth and the Moon, revealed by lunar
rocks, suggest that they must have formed at the same distance from the Sun.
Since the capture theory long favored by Urey seemed to require that the
Moon originated elsewhere, he abandoned it after the Apollo missions returned
samples of the lunar surface.
Not long before he died, Urey showed some acceptance for a new idea - that
the Moon was formed when a body the size of Mars crashed into Earth and threw
a cloud of vaporized material into orbit. Subsequently, the Moon formed from
this debris. This "giant impact" theory seems to be in favor now and it does
seem to satisfy some of the chemical data.
But it does not solve all the mysteries. In time, this notion may too be
quashed by new information from the "inconstant moon."
|
| 560.271 | GALILEO Update - January 29 | ADVAX::KLAES | All the Universe, or nothing! | Tue Jan 29 1991 18:54 | 23 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/29/91
Date: 29 Jan 91 17:46:06 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 29, 1991
Today, the planned Sun acquisition activity was successfully
completed with the Galileo spacecraft. Tomorrow, the CDS "B" (Command
Data Subsystem) prime and extended memory readout activity will be
performed. This activity is similar to that successfully performed
for CDS "A" on January 22.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.272 | GALILEO Update - January 30 | ADVAX::KLAES | All the Universe, or nothing! | Wed Jan 30 1991 18:35 | 28 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/30/91
Date: 30 Jan 91 18:45:42 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 30, 1991
The health of the Galileo spacecraft continues to be excellent.
Today, the CDS "B" (Command Data Subsystem) prime and extended memory
readout activity is presently in process and proceeding well.
Tomorrow, the Low Gain Antenna (LGA) will be switched from LGA-2
(the aft-facing boom mounted antenna) to LGA-1 (the forward-facing
antenna) to provide communication capability given the changing
sun-spacecraft-Earth geometry. Additionally, a planned sun
acquisition activity will be performed to maintain a thermally safe
sun pointed attitude.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.273 | GALILEO Update - January 31 | ADVAX::KLAES | All the Universe, or nothing! | Fri Feb 01 1991 14:10 | 56 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/31/91
Date: 31 Jan 91 18:33:33 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 31, 1991
The Galileo spacecraft is 25.6 million miles from Earth, and 87
million miles from the Sun. Its speed in solar orbit is 81,773 mph.
The round-trip communication time is 4 minutes, 35 seconds.
Galileo's health and performance continue to be excellent. The
spacecraft is spinning at 2.89 rpm, with the spin axis pointed within
2 degrees of the Sun, updated every other day. Telemetry at 40 bits
per second includes Magnetometer, Dust Detector and star buffer
readouts. The last, a record of star intensities taken by the star
sensor, is used to update the attitude control team's star catalog.
As of today, communications will use the primary Low Gain Antenna,
located on the sunlit side of the spacecraft.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 01/31/91
Date: 31 Jan 91 19:37:56 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
January 31, 1991
Yesterday, the CDS "B" (Command Data Subsystem) memory readout
activity was successfully completed with no anomalies or parity errors
observed. Today, the planned Low Gain Antenna switch from LGA2 to LGA1
was successfully completed. In addition to the antenna switch, a
planned sun acquisition activity was also successfully completed.
Tomorrow, spacecraft activity will be limited to a cruise science
memory readout for the MAG (Magnetometer) and DDS (Dust Detector)
instruments.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.274 | GALILEO Update - February 1 | ADVAX::KLAES | All the Universe, or nothing! | Mon Feb 04 1991 14:58 | 77 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/01/91
Date: 1 Feb 91 20:18:48 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 1, 1991
As of noon (PST) Thursday, January 31, 1991, the Galileo spacecraft
is 25,603,660 miles from Earth and traveling at a heliocentric speed of
81,780 miles per hour; distance to the Sun is 87,012,680 miles (0.91 AU).
Round trip light time is 4 minutes, 32 seconds.
A command was sent on January 28 to reset the Command Loss Timer to 144
hours, the planned value in preparation for the LGA-2 (Low Gain Antenna-2) to
LGA-1 antenna switch on January 31. Subsequent to the antenna switch, commands
were sent on January 31 to set the Command Loss Timer to 240 hours, its planned
value for this mission phase.
The LGA antenna switch event (LGA-2 to LGA-1) was successfully performed,
as planned, on January 31. The antenna switch event was commanded from the
stored sequence. This fourth antenna switch is the final LGA 1/2 switch event.
From this point on, no further use of the LGA-2 antenna is planned.
Four more sun acquisition activities were successfully completed on
January 25, 27, 29 and 31. To date, eight sun acquisitions out of the 17
planned in VE-12 (Venus-Earth 12 sequence) have been completed. Following each
sun acquisition activity, star buffer memory readouts were successfully
completed. These readouts provide valuable star intensity information which
is being used to update the attitude control star catalog.
Two USO (Ultra Stable Ocsillator) calibration tests were successfully
completed on January 26 and 28. These tests provide trend information to
characterize this ultra-stable downlink frequency source.
Cruise Science Memory Readouts (MROs) were successfully completed on
January 25 and 28 for the DDS (Dust Detector) and MAG (Magnetometer) science
instruments.
Another RPM (Retro Propulsion Module) thruster maintenance exercise was
successfully completed on January 25. Only 10 of the 12 10-N thrusters were
"flushed" during this exercise. The P-thrusters were not flushed because they
are being used for all the sun acquisition activities in VE-12; spacecraft
operation throughout the maintenance operation was normal and without incident.
The CDS "B" (Command Data Subsystem) prime and extended memory was
successfully read out on January 30; no parity errors or anomalies were
observed with the memory readout activity.
The AC/DC bus imbalance measurement exhibited some minor activity. The
AC measurement dropped about 2 DN and reads 45.8 volts. The DC measurement
fluctuated about 36 DN (up 13 DN, then down 23 DN about 3 hours later) and
reads near 10.6 volts. The DC measurement changes occurred during a period of
no spacecraft activity. All other power-related and spacecraft telemetry are
normal.
At the beginning of the planned tracking pass on January 27, two command
lock change indications were observed in both CDS A and B telemetry. This is
the fourth occurrence of this anomaly. The first and fourth occurrences were
observed over the 70 meter Canberra station on September 13, 1990, and
January 27, 1991. The second occurrence was during the 70 meter Goldstone
track on November 7, 1990 and resulted from a CPA (Command Processor Assembly)
hardware failure. The third occurrence was observed during the Canberra 70
meter track on January 22. There was no indication of any abnormal spacecraft
operation as a result of any of these indications. The spacecraft continues
to properly receive and process all commands. Investigation of these
unexplained indications is in process.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.275 | GALILEO Update - February 4 | ADVAX::KLAES | All the Universe, or nothing! | Tue Feb 05 1991 14:14 | 27 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/04/91
Date: 4 Feb 91 19:54:54 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 4, 1991
The Galileo spacecraft successfully completed the planned sun
acquisition on February 2. Today, spacecraft activities will consist
of a cruise science memory readout for the DDS (Dust Detector) and MAG
(Magnetometer) instruments, a planned sun acquisition, and a USO
(Ultra Stable Oscillator) calibration test. The Command Loss Timer
will also be reset to 240 hours and and the Star Scanner high voltage
will be turned off to protect its photocathode from Earth light.
Earth will appear as a bright body to the Star Scanner from February 6
to February 24.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.276 | GALILEO Update - February 6 | ADVAX::KLAES | All the Universe, or nothing! | Wed Feb 06 1991 19:13 | 23 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/06/91
Date: 6 Feb 91 19:17:04 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 6, 1991
Yesterday, no spacecraft activity was planned for the Galileo
spacecraft. Today, a planned Sun acquisition will be performed to
maintain a thermally safe Sun pointed attitude. Tomorrow, a cruise
science memory readout is planned for the MAG (Magnetometer) and DDS
(Dust Detector) science instruments.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.277 | GALILEO Update - February 7 | ADVAX::KLAES | All the Universe, or nothing! | Thu Feb 07 1991 18:55 | 25 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/07/91
Date: 7 Feb 91 18:32:37 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 7, 1991
The status reports for the Galileo spacecraft has been
relatively short lately because everthing has been going well with the
spacecraft, and its health continues to be excellent. Yesterday's
planned sun acquisition activity was successfully completed. Today,
spacecraft activity will be limited to a cruise science memory readout
for the DDS (Dust Detector) and MAG (Magnetometer) instruments.
Tomorrow, another Sun acquisition is planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.278 | GALILEO Update - February 7 (#2) | ADVAX::KLAES | All the Universe, or nothing! | Fri Feb 08 1991 21:02 | 90 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 02/07/91
Date: 7 Feb 91 23:04:29 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 7, 1991
As of noon (PST) Thursday, February 7, 1991, the Galileo
spacecraft is 28,217,080 miles from Earth and traveling at a
heliocentric speed of 80,320 miles per hour; distance to the Sun is
89,236,840 miles (0.97 AU). Round trip light time is 5 minutes, 0 seconds.
A command was successfully sent on February 4 to reset the Command Loss
Timer to 240 hours, its planned value for this mission phase.
Three more sun acquisition activities were successfully completed on
February 2, 4 and 6. To date, twelve sun acquisitions out of the 17 planned
in VE-12 (Venus-Earth 12 sequence) have been completed. Following each sun
acquisition activity, star buffer memory readouts were successfully completed.
These readouts provide valuable star intensity information which is being used
to update the attitude control star catalog.
Two USO (Ultra Stable Oscillator) calibration tests were successfully
completed on February 2 and 5. These tests provide trend information to
characterize this ultra-stable downlink frequency source.
Cruise Science Memory Readouts (MROs) were successfully completed on
February 1, 4 and 7 for the DDS (Dust Detector) and MAG (Magnetometer) science
instruments.
The star scanner high voltage was successfully turned off, as planned, by
stored sequence command on February 4. This action was taken to protect the
star scanner photo cathode from Earth light. The Earth will be in the star
scanner field of view from February 5 through February 22.
Commands were sent on February 1 modifying the engineering telemetry
variable format to provide greater visibility into the AC/DC bus imbalance
anomaly. The format changes allow a selected set of measurements (voltages,
currents and temperatures) to be sampled as a group every 20 seconds rather
than 240 seconds. In early April when the telecommunication link can support
1200 bits/second, the sample time between the measurement set will be improved
from 20 seconds to 0.66 second.
A command was sent on January 31 after the LGA-2 (Low Gain Antenna-2) to
LGA-1 to turn off the S-Band ranging channel to improve the downlink
performance over 70 meter Canberra station. Additionally, a Delayed Action
Command (DAC) was sent on February 2 for execution on February 3 after the
planned USO test on February 2. These actions were taken in response to low
signal to noise observed on the downlink. Later on January 31, while being
tracked by the 70 meter Madrid antenna, a substantial improvement (about 3db)
in link performance was noticed. Furthermore, in subsequent days, performance
over the 70 meter Canberra station improved to near predicted link values. The
cause of the observed performance fluctuation is being investigated.
The AC/DC bus imbalance measurement exhibited some minor activity. The
AC measurement has fluctuated about 2 DN and now reads 45.6 volts. The DC
measurement fluctuated about 6 DN and now reads 11.4 volts. All other
power- related telemetry and spacecraft telemetry are normal.
The Project reviewed and approved the VE-14 sequence Preliminary Command
and sequence generation product on February 5, 1991. This sequence controls
spacecraft activities from February 18 to April 29, 1991.
The German Space Operations Center (GSOC) reports that installation of
upgraded telemetry and command computer hardware has been completed and
regression testing of the software and complete system has begun. GSOC is in
the process of testing German ground data system capabilities in preparation
for their support of Galileo cruise science operations scheduled to begin in
September 1991. JPL personnel are assisting by evaluating data products such
as science data record and replay telemetry outputs.
A meeting was held on February 6th to review plans for in-flight testing
of the prototype Big Viterbi Decoder (BVD) being developed by the Deep Space
Network. The BVD will decode the additional new convolutional code
(R=1/4, K=15) which was added to the Galileo spacecraft before launch to
provide increased telemetry performance during Jupiter operations. The
conclusion of the meeting was that plans for the test were in excellent shape.
The tests with the Galileo spacecraft currently planned for late May and early
June.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.279 | GALILEO Update - February 11 | ADVAX::KLAES | All the Universe, or nothing! | Tue Feb 12 1991 13:30 | 23 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/11/91
Date: 11 Feb 91 16:58:54 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 11, 1991
The Galileo spacecraft's health continues to be excellent.
Yesterday, Galileo successfully performed the planned sun acquisition
activity. Today, no spacecraft activity is planned. Tomorrow, a USO
(Ultra Stable Oscillator) test and a Sun acquisition are planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is?
|_____|/ |_|/ |_____|/ | We do!
|
| 560.280 | GALILEO Update - February 12 | ADVAX::KLAES | All the Universe, or nothing! | Tue Feb 12 1991 19:02 | 22 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/12/91
Date: 12 Feb 91 18:02:26 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 12, 1991
Today, the Galileo spacecraft successfully completed a planned
USO (Ultra Stable Oscillator) test and a Sun acquisition activity.
Tomorrow, a cruise science memory readout will be performed for the
DDS (Dust Detector) and MAG (Magnetometer) instruments.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.281 | GALILEO Update - February 13 | ADVAX::KLAES | All the Universe, or nothing! | Wed Feb 13 1991 20:30 | 26 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/13/91
Date: 13 Feb 91 18:07:03 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 13, 1991
The health of the Galileo spacecraft continues to be excellent.
Today, the spacecraft successfully completed the planned cruise
science memory readout for the DDS (Dust Detector) and MAG
(Magnetometer) instruments. Tomorrow, activities will consist of
uplinking of the VE-14 (Venus-Earth 14) sequence memory load, and
performing another sun acquisition.
February 9 marked the one year anniversary of Galileo's flyby of Venus.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.282 | GALILEO Update - February 14 | ADVAX::KLAES | All the Universe, or nothing! | Thu Feb 14 1991 19:17 | 24 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/14/91
Date: 14 Feb 91 19:14:09 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 14, 1991
Today, the VE-14 (Venus-Earth) sequence memory load is being
uplinked to the Galileo spacecraft. The loading activity is presently
in progress and is expected to be completed by 11:00 AM (PST).
Subsequent to the memory load, a planned Sun acquisition activity will
be performed. Tomorrow, another of the planned periodic RPM (Retro
Proplusion Module) 10-Newton thruster maintenance operation is planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
\
|
| 560.283 | GALILEO Update - February 14 (#2) | ADVAX::KLAES | All the Universe, or nothing! | Fri Feb 15 1991 13:10 | 55 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 02/14/91
Date: 15 Feb 91 01:50:44 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 14, 1991
As of noon (PST) Thursday, February 14, 1991, the Galileo
spacecraft is 30,440,670 miles from Earth and traveling at a
heliocentric speed of 78,590 miles per hour; distance to the Sun is
91,968,810 miles (0.99 AU). Round trip light time is 5 minutes, 24
seconds.
A command was successfully sent on February 11 to reset the Command
Loss Timer to 240 hours, its planned value for this mission phase.
Four more Sun acquisition activities were successfully completed
on February 8, 10, 12, and 14. To date, sixteen Sun acquisitions out
of the 17 planned in VE-12 (Venus-Earth 12 sequence) have been completed.
Two USO (Ultra Stable Oscillator) calibration tests were
successfully completed on February 8 and 12. These tests provide
trend information to characterize this ultra-stable downlink frequency
source.
A Cruise Science Memory Readout (MRO) was successfully completed
on February 13 for the DDS (Dust Detector) and MAG (Magnetometer)
science instruments.
The VE-14 sequence memory load was successfully transmitted and
received by the spacecraft on February 14. The VE-14 sequence
controls spacecraft activities from February 18 to April 29, 1991. In
addition to normal routine operations such as sun acquisitions,
SITURNS, RPM (Retro Propulsion Module) flushing, telecommunications
tests and science MRO activities, this sequence contains the HGA (High
Gain Antenna) deployment and LGA-2 (Low Gain Antenna-2) retraction
activities as well as windows for the TCM-9B (Trajectory Correction
Maneuver 9B) planned for March 19 and 20.
The AC/DC bus imbalance measurements exhibited some activity.
The AC measurement fluctuated 2 DN and now reads 45.4 volts. The DC
measurement dropped 24 DN and now reads near 8.4 volts. The large
drop occurred while the spacecraft was quiescent and not being tracked.
All other power-related telemetry and spacecraft telemetry are normal.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.284 | GALILEO Update - February 15 | ADVAX::KLAES | All the Universe, or nothing! | Sun Feb 17 1991 19:16 | 43 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/15/91
Date: 16 Feb 91 03:13:35 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 15, 1991
The status of the Galileo spacecraft is as follows:
o System Power Margin - 69 watts
o Spin Configuration - All-Spin - cruise mode
o Spin Rate/Sensor - 2.89rpm/spin detector
o Spacecraft Attitude Sun Point Angle - approximately
0.7 degree plus or minus 0.3 degree
o Downlink telemetry rate/antenna - 40 bits/second
(uncoded)/LGA-1 (Low Gain Antenna-1)
o General Thermal Control - all temperatures within
acceptable range
o RPM Tank Pressures - all within acceptable range
Yesterday, the Galileo spacecraft successfully received the VE-14
(Venus-Earth 14) sequence memory load and completed the planned sun
acquisition. Today, another routine, periodic RPM (Retro Propulsion
Module) 10-Newton thruster maintenance activity will be performed.
Spacecraft activity over the weekend will be limited to a sun
acquisition on Februray 17. This will be the last sun acquisition in
the VE-12 sequence.
A total of 3210 real-time commands have been transmitted to
Galileo. Of these, 1792 have been pre-planned in the sequence design
and 1418 were not. In the past week, a total of 4 real-time commands
were sent; only one was pre-planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.285 | | PAXVAX::MAIEWSKI | | Tue Feb 19 1991 18:18 | 7 |
| So what happened to Venus-Earth 13? We seemed to go straight from VE-12
to VE-14.
Also, why are they called Venus-Earth. At this point shoudln't they be
Earth-Earth? Or perhaps Earth-(what ever asteroid)?
George
|
| 560.286 | GALILEO Update - February 18 | ADVAX::KLAES | All the Universe, or nothing! | Tue Feb 19 1991 19:01 | 35 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/18/91
Date: 19 Feb 91 03:42:25 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 18, 1991
The Galileo spacecraft health continues to be excellent. Today, the
VE-12 (Venus-Earth 12) stored sequence ends and the VE-14 sequence begins.
Activities planned for today consist of:
o disabling the AACS (Attitude and Articulation Control
Subsystem) sun gate function and its associated fault
protection now that the spacecraft is beyond a 1 AU
solar distance
o performing a planned sun acquisition to maintain a
thermally safe sun pointed attitude
o commanding to reset the Command Loss Timer to 240 hours
o performing a USO (Ultra Stable Oscillator) test
There are no spacecraft activities are planned for tomorrow.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.287 | 12 - superstition - 14? | 42110::RICKETTS | Have you tried kicking it? | Wed Feb 20 1991 08:49 | 17 |
| re .285
I don't know if it is actually official or semi-official policy,
but I think that many people in NASA long since decided to avoid
using the number 13 whenever possible. Probably after nearly losing
Apollo 13. Scientifically, I suppose it can be written off as
groundless superstition, but I wouldn't fancy tempting fate that way
either. It doesn't actually cost anything much to skip a number
like that, and if it makes people feel better to miss it out (or
style it 12A or some such), then the improvement in morale probably
outweighs any minor inconvenience. I wonder how many 'lucky rabbits
feet' and other such talismans have been into space along with the
astronauts?
I visited KSC (as a tourist) last week, and I recall that my
girlfriend noticed something else that went straight from 12 to
14; I think it may have been the seat numbers in the IMAX theatre.
Ken
|
| 560.288 | GALILEO Update - February 20 | ADVAX::KLAES | All the Universe, or nothing! | Thu Feb 21 1991 18:25 | 29 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/20/91
Date: 21 Feb 91 02:18:21 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 20, 1991
The Galileo spacecraft is 31.5 million miles from Earth, and 93.7
million miles from the Sun. Its speed in solar orbit is just over
77,500 mph, and the two-way communication time with Earth is 5 minutes
39 seconds.
The spacecraft is doing very well, carrying out its new
operational sequence (sent to spacecraft computers last week), making
measurements of the interplanetary environment and carrying out
routine engineering tests and other normal activities. Today,
spacecraft activities will be limited to a sun acquisition. Tomorrow,
no spacecraft activities are planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.289 | GALILEO Updates - February 21-22 | ADVAX::KLAES | All the Universe, or nothing! | Sun Feb 24 1991 17:53 | 101 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/21/91
Date: 23 Feb 91 03:42:16 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 21, 1991
Yesterday, the Galileo spacecraft successfully completed a
planned Sun acquisition. Tomorrow, another Sun acquisition is
scheduled and cruise memory readouts for the DDS (Dust Detector) and
MAG (Magnetometer) instruments are planned. Over the coming weekend,
activities will be limited to a USO (Ultra Stable Oscillator)
calibration test on February 24.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/22/91
Date: 23 Feb 91 04:09:34 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 22, 1991
As of noon (PST) Thursday, February 21, 1991, the Galileo
spacecraft is 32,250,780 miles from Earth and was traveling at a
heliocentric speed of 76,670 miles per hour; distance to the Sun is
95,124,290 miles (1.04 AU). Round trip light time is 5 minutes, 44
seconds.
A NO-OP command was successfully sent on February 18 to reset the
Command Loss Timer to 240 hours, its planned value for this mission phase.
Commands were sent on February 18 to disable the AACS (Attitude
and Articulation Control Subsystem) sun gate function and its associated
fault protection now that the spacecraft is beyond a 1 AU solar distance.
Disabling the sun gate function allows greater off sun angles thereby
reducing the number of sun point corrections required.
Three more sun acquisition activities were successfully completed
on February 16, 18 and 20. The sun acquisitions on February 18 and 20
were executed from the VE-14 (Venus-Earth 14) stored sequence which
began on February 18. Two more sun acquisitions are planned in VE-14
before returning to dual-spin operation on February 25.
Another USO (Ultra Stable Oscillator) calibration test was
successfully completed on February 18. This test provides trend
information to characterize this ultra-stable downlink frequency source.
Another RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance activity was successfully completed on February
15. Only 10 of the 12 thrusters were exercised during this activity
since the two P-thrusters are periodically used for sun pointing
activities; spacecraft operation during this activity was normal.
Cruise Science Memory Readouts (MROs) were successfully completed on
February 18 for the DDS (Dust Detector) and MAG (Magnetometer) instruments.
The AC/DC bus imbalance measurements exhibited some activity.
The AC measurement fluctuated about 4DN and now reads 45.6 volts. The
DC measurement dropped 6 DN and now reads 8.2 volts. All other
power-related telemetry and spacecraft telemetry are normal.
Project reviewed and approved the EE-2/3 (Earth-Earth sequence)
on February 20, 1991. The EE-2/3 covers the time period from July 22,
1991 to October 31, 1991.
The SSI (Solid State Imaging) camera cover deployment review was
held on February 19. A comparison of cover deployment ground test and
expected flight conditions indicated some differences. However, most
notable was the delta temperature between the SSI cover and the
baffle. During ground test this temperature difference was near zero
but in-flight the delta temperature is not expected to exceed a worst
case of 25 degrees C. This difference is not anticipated to pose a
problem since analysis indicates a delta temperature even as high as
40 to 50 degrees C will not adversely affect deployment.
The review board generated several RFAs (Request for Action)
including follow-up actions to define the safest scan platform
position for cover deployment and to verify adequate mechanical
clearance exist between the SSI cover and the scan platform shade
blankets. These actions are expected to be completed in about a week.
The SSI cover is scheduled to be deployed on May 9, 1991.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.290 | GALILEO Update - February 25 | ADVAX::KLAES | All the Universe, or nothing! | Tue Feb 26 1991 18:35 | 30 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/25/91
Date: 25 Feb 91 19:43:48 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 25, 1991
The health of the Galileo spacecraft continues to be excellent.
Today's activities will consist of:
o Performing a Sun acquisition.
o Turning on the star scanner high voltage.
o Transitioning from all-spin to dual-spin operation.
o Performing a cruise science memory readout for the EUV
(Extreme Ultraviolet Spectrometer), MAG (Magnetometer),
and DDS (Dust Detector) instruments.
o Resetting the Command Loss Timer to 240 hours.
Tomorrow, no spacecraft activity is planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.291 | GALILEO Update - February 27 | ADVAX::KLAES | All the Universe, or nothing! | Thu Feb 28 1991 17:01 | 39 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/27/91
Date: 28 Feb 91 03:11:48 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 27, 1991
The Galileo spacecraft is almost 33.5 million miles from
Earth; it is just over 98 million miles from the Sun. Its speed in
solar orbit is about 75,000 mph. Round-trip communication time
with Earth is almost six minutes.
Spacecraft health and mission performance are excellent. On
Monday, February 25, the spacecraft was returned from the all-spin
mode at about 2.9 rpm to dual-spin at about 3.15 rpm. In the dual-
spin mode, the lower section containing the camera and other
instruments is de-spun and held fixed relative to surrounding
space. The spacecraft's star tracker must be able to detect a
pattern of stars to maintain this mode; at present, the spacecraft
must also orient its "top" toward the Sun for thermal protection.
For the past six weeks, in this spacecraft attitude, suitable guide
stars were not available until now.
Galileo will continue gathering and reading out scientific
data, checking out instruments and other subsystems, and conducting
routine maintenance operations in the cruise mode. On the ground,
the Galileo team is developing and testing future sequences and
planning for the asteroid encounter late this year.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.292 | GALILEO Update - February 28 | ADVAX::KLAES | All the Universe, or nothing! | Thu Feb 28 1991 17:37 | 32 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 02/28/91
Date: 28 Feb 91 18:30:08 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 28, 1991
Today, several activities are planned for the Galileo spacecraft
consisting of:
o Another RFS (Radio Frequency Subsystem) TLC (Tracking
Loop Capacitor) characterization test.
o A UVS (Ultraviolet Spectrometer) Lyman Alpha data collection.
o MAG (Magnetometer) and DDS (Dust Detector) memory readout.
Tomorrow, several activities are planned including:
o EPD (Energetic Particles Detector) motor maintenance.
o EUV (Extreme Ultraviolet Spectrometer) and EPD memory readout.
o a SITURN (a small maneuver to keep the High Gain Antenna
pointed at the sun).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.293 | GALILEO Update - February 28 (#2) | ADVAX::KLAES | All the Universe, or nothing! | Fri Mar 01 1991 14:06 | 69 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 02/28/91
Date: 28 Feb 91 23:27:56 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
February 28, 1991
As of noon (PST) Thursday, February 28, 1991, the Galileo
spacecraft is 33,653,740 miles from Earth and traveling at a
heliocentric speed of 74,640 miles per hour; distance to the Sun is
98,620,210 miles (1.07 AU). Round trip light time is 6 minutes, 0
seconds.
A NO-OP command was successfully sent on February 25 to reset the
Command Loss Timer to 240 hours, its planned value for this mission phase.
Two more sun acquisition activities were successfully completed
on February 22 and 25. These were the final two sun acquisitions
performed in the all-spin mode during this mission phase.
The star scanner high voltage was reactivated and the spacecraft
successfully returned to dual-spin operation on February 25.
Cruise Science Memory Readouts (MROs) were performed on the EUV
(Extreme Ultraviolet Spectrometer), MAG (Magnetometer) and DDS (Dust
Detector) instruments on February 25; readouts were also performed for
the DDS and MAG instruments on February 28.
The first of seven planned UVS (Ultraviolet Spectrometer) Lyman
Alpha data collection activities was successfully performed on
February 28, subsequent to the resumption of dual-spin operation on
February 25.
Another USO (Ultra Stable Oscillator) calibration test was
completed on February 24 to provide trend information characterizing
this downlink frequency source.
Commands were sent on February 27 to change the engineering
variable telemetry map to include the measurements needed for the
upcoming CDU (Command Data Unit) and RFS (Radio Frequency Subsystem)
tests. Subsequent to these tests, changes will be made restoring the
map to the previous measurement configuration used to maximize
visibility into the AC/DC bus imbalance anomaly.
Another radio frequency receiver Tracking Loop Capacitor test was
completed on February 28. This test provides trend information
characterizing the performance of the RF command receiver.
The AC/DC bus imbalance measurements exhibited some activity.
The AC measurement fluctuated 2 DN and now reads 45.8 volts. The DC
measurement fluctuated 5 DN and now reads 9.1 volts. All other
power-related telemetry and subsystem telemetry are normal. No
notable changes were observed in the bus imbalance measurements after
returning to dual-spin operation on February 25.
The Project reviewed and approved the Cruise Plan for the EE-1
(Earth-Earth) sequence on February 26, 1991. This sequence controls
spacecraft activities from April 29, 1991 to July 22, 1991.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.294 | GALILEO Update - March 1 | ADVAX::KLAES | All the Universe, or nothing! | Mon Mar 04 1991 17:20 | 51 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/01/91
Date: 2 Mar 91 01:06:03 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
March 1, 1991
The status of the Galileo spacecraft as of end of the day of
February 28 is as follows:
o System Power Margin - 64 watts
o Spin Configuration - Dual-Spin - cruise mode
o Spin Rate/Sensor - 3.15 rpm
o Spacecraft Attitude Sun Point Angle - approximately
3.7 degrees (lagging) plus or minus 0.3 degree
o Downlink telemetry rate/antenna - 40 bits/second
(uncoded)/LGA-1 (Low Gain Antenna-1)
o General Thermal Control - all temperatures within
acceptable range
o RPM Tank Pressures - all within acceptable range
o Probe - powered off, temperatures nominal
o Command Loss Timer Setting - 240 hours
Time To Initiation - 216 hours
Today, the spacecraft activities will consist of:
o Powering on the EPD (Energetic Particles Dectector)
instrument for its periodic motor maintenance activity.
o Performing a SITURN activity to lead the sun.
o Performing an EUV (Extreme Ultraviolet Spectrometer)
memory readout.
No spacecraft activities are planned over the weekend.
A total of 3239 real-time commands have been transmitted to
Galileo. Of these, 1803 have been pre-planned in the sequence design
and 1436 were not. In the past week, a total of 19 real-time commands
were sent; one was pre-planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.295 | When do the SITURNs stop? | JANUS::BARKER | Jeremy Barker - T&N/CBN Diag. Eng. - Reading, UK | Tue Mar 05 1991 15:13 | 5 |
| Does anyone know how far from the sun Galileo must be before it no longer
needs to keep pointing towards the sun, and how far away must it be before
the high-gain antenna can be unfurled?
jb
|
| 560.296 | | DECWIN::FISHER | Pursuing an untamed ornothoid | Tue Mar 05 1991 15:36 | 5 |
| I believe that the HGA is not due to be opened till the next pass by Earth
which is not for a couple years, if I remember right. I don't know the
actual distance involved.
Burns
|
| 560.297 | Sooner than that | 15372::LEPAGE | Pumping Irony | Tue Mar 05 1991 15:55 | 8 |
| Re:.296
I think that the HGA will be opened much sooner than that. May,
1991 sticks in my mind. I would geuss that it will be needed for the
asteriod flyby this coming October.
Drew
|
| 560.298 | | DECWIN::FISHER | Pursuing an untamed ornothoid | Wed Mar 06 1991 15:46 | 28 |
| I loose. Checking the STS34 press kit (note .17), we find...
---
FIRST EARTH PASS
Approaching Earth for the first time about 14 months after launch, the
Galileo spacecraft will observe, from a distance, the nightside of Earth and
parts of both the sunlit and unlit sides of the moon. After passing Earth,
Galileo will observe Earth's sunlit side. At this short range, scientific data
are transmitted at the high rate using only the spacecraft's low-gain
antennas. The high-gain antenna is to be unfurled like an umbrella, and its
high-power transmitter turned on and checked out, about 5 months after the
first Earth encounter.
---
I guess that would make the HGA deploy April or May if plans have not changed.
I wonder what the wait was for? I suppose if the HGA is on the non-spinning
section, they probably had to wait till they got out of all-spin mode, at least.
On the other hand, if it is in the spinning section, they might have saved
some fuel by deploying while it was in all-spin mode. (The deploy would have
slowed down the spin. They would then use less fuel to stop the non-spinning
section when coming out of all-spin mode. In addition, the spinning section
would not have slowed down as much, so they would use less fuel to spin it back
up to the correct RPM).
Burns
|
| 560.299 | | PRAGMA::GRIFFIN | Dave Griffin | Wed Mar 06 1991 16:25 | 11 |
| Re: .298
I believe the deployment was thermal-related. Galileo wasn't designed
to handle a trip towards the Sun (i.e., to Venus), and I recall that the
HGA couldn't take the heat when it was unfurled -- so for mission safety
reasons they've delayed the deployment till things cooled down a bit.
[Why it wasn't done prior to the first Earth encounter? -- no idea. Perhaps
this is what you were asking.]
- dave
|
| 560.300 | | DECWIN::FISHER | Pursuing an untamed ornothoid | Thu Mar 07 1991 15:20 | 8 |
| Yes, I know it was not deployed right off because of heat issues nearer the
sun than Venus. I was wondering why it was not deployed right away after the
first Earth encounter, and speculated it might be related to the change of spin
modes that were required. (I also thought they might be concerned about drag
during Earth II, but that is clearly not the case, since they are deploying
between I and II).
Burns
|
| 560.301 | GALILEO Updates - March 6-8 | ADVAX::KLAES | All the Universe, or nothing! | Mon Mar 11 1991 19:54 | 154 |
| Date: 8 Mar 91 22:41:20 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@decwrl.dec.com
(Ron Baalke)
Subject: Galileo Update - 03/06/91
GALILEO STATUS REPORT
March 6, 1991
Today, the Galileo spacecraft is traveling at 72,800 miles per
hour relative to the Sun as it arcs outward slightly beyond the orbit
of Earth. The spacecraft is 102 million miles from the Sun and 35
million miles from Earth. Round-trip communication time is 6 minutes,
11 seconds.
During the past week the spacecraft has conducted routine
housekeeping activities. All science experiments are powered off
except for the Heavy Ion Counter (HIC), Dust Detector (DDS)
instrument, Magnetometer (MAG), Extreme Ultraviolet Spectrometer (EUV)
instrument and Ultraviolet Spectrometer (UVS), which are or will be
taking data during the cruise phase.
On Friday, March 8, routine maintenance of the thruster system is
planned. During this procedure, thrusters that have not been used recently
are fired briefly to keep the thrusters and oxidizer lines cleared.
Today, the following is planned for the Galileo spacecraft:
o Cruise Science memory readouts of the MAG, DDS and EUV
instruments; the first of these is in process.
o Radio frequency receiver and command detector
performance characterization tests.
There are no spacecraft activities planned for tomorrow.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
Date: 9 Mar 91 00:56:08 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@decwrl.dec.com
(Ron Baalke)
Subject: Galileo Update - 03/07/91
GALILEO STATUS REPORT
March 7, 1991
As of noon (PST) Thursday, March 7, 1991, the Galileo spacecraft
is 34,675,090 miles from Earth and traveling at a heliocentric speed
of 72,550 miles per hour; distance to the Sun is 102,404,120 miles
(1.1 AU). Round trip light time is 6 minutes, 12 seconds.
A NO-OP command was successfully sent on March 4 to reset the
Command Loss Timer to 240 hours, its planned value for this mission phase.
A 10-degree SITURN was successfully completed on March 1. The
turn resulted in the spacecraft leading the sun by about 5.5 degrees;
spacecraft performance throughout the activity was normal.
The EPD (Energetic Particle Detector) instrument was powered on
March 1 to perform its periodically required stepper motor maintenance.
The activity was accomplished successfully and the EPD was powered off
after a planned memory readout.
Cruise Science Memory Readouts (MROs) were performed on the MAG
(Magnetometer) and DDS (Dust Detector) on March 6; EUV (Extreme
Ultraviolet Spectrometer) memory readouts were also performed on March
1 and March 6.
Another USO (Ultra Stable Oscillator) calibration test was
completed on March 5 to provide trend information characterizing this
downlink frequency source.
A telecommunications equipment test was successfully completed on
March 6. This test is periodically performed to characterize the
performance of the receiver and command detector uplink hardware elements.
The AC/DC bus imbalance measurements exhibited some activity.
The AC measurement fluctuated 3 DN and now reads 45.4 volts. The DC
measurement fluctuated nearly 160 DN. The large measurement
fluctuations began about 3.5 days after returning to dual-spin
operation on February 25. Sometime between the end of track on
February 28 and start of track on March 1, the DC measurement
increased 75 DN from about 8.8 volts to 17.9 volts and remained near
18 volts through the end of track on March 3. At the start of track
on March 4, the measurement was found to have dropped about 75 DN and
was reading near 9 volts. These fluctuations occurred while the
spacecraft was quiescent, i.e., no electrical load switching or
sequencing activity. All other power-related telemetry and subsystem
telemetry are normal.
Representatives from the DSN (Deep Space Network) and Project met
last week to discuss display capabilities planned for the DSN Network
Operations Center (NOCC) upgrade. The Project is concerned that
existing capabilities for DSN displays in the Galileo Mission Support
Area (MSA) may not be available after the upgrade without
modifications to Project hardware and software. The Project has been
assuming that the DSN upgrades would be transparent to Project
operations support and, in particular, that current interfaces and
support commitments would be maintained. Further meetings and
discussions are planned to identify and resolve issues.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
Date: 9 Mar 91 01:03:07 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@decwrl.dec.com
(Ron Baalke)
Subject: Galileo Update - 03/08/91
GALILEO STATUS REPORT
March 8, 1991
The status of the Galileo spacecraft as of end of day March 7 was
as follows:
o System Power Margin - 64 watts
o Spin Configuration - Dual-Spin - cruise mode
o Spin Rate/Sensor - 3.15 rpm/star scanner
o Spacecraft Attitude Sun Point Angle - approximately
0.3 degrees (leading) plus or minus 0.3 degree
o Downlink telemetry rate/antenna - 40 bits/second
(uncoded)/LGA-1 (Low Gain Antenna-1)
o General Thermal Control - all temperatures within
acceptable range
o RPM Tank Pressures - all within acceptable range
o Probe - powered off, temperatures nominal
o Command Loss Timer Setting - 240 hours
Time To Initiation - 144 hours
A total of 3240 real-time commands have been transmitted to
Galileo. Of these, 1804 have been pre-planned in the sequence design
and 1436 were not. In the past week, only one real time command was
sent and it was pre-planned.
Today's spacecraft activities will consist of performing a
periodic RPM (Retro Propulsion Module) thruster maintenance and
performing a MAG (Magnetometer) instrument science memory readout. No
spacecraft activities are planned for Saturday or Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
|
| 560.302 | GALILEO Update - March 11 | ADVAX::KLAES | All the Universe, or nothing! | Tue Mar 12 1991 12:41 | 24 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/11/91
Date: 12 Mar 91 00:44:32 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
March 11, 1991
The Galileo spacecraft health continues to be excellent. Today,
spacecraft activities will consist of performing cruise science memory
readouts for the EUV (Extreme Ultraviolet Spectrometer), MAG
(Magnetometer) and DDS (Dust Detector) instruments, and collecting UVS
(Ultraviolet Spectrometer) Lyman-Alpha data. Tomorrow, no spacecraft
activities are planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.303 | Jupiter or Bust? | 58378::R_YURKIW | | Thu Mar 14 1991 14:36 | 15 |
| I have one question with regards to the AC/DC bus voltage
imbalance. Obviously this is a problem that cropped up with
the spacecraft. the question I have is what is the possible
consequences of this fault.
What has caused the fault in the first place?
What is the worst case scenerio if this problem gets worse?
Are there any spacecraft operations that already have been
impaired because of this problem?
Thanks in advance
Roger
|
| 560.304 | An explanation of the problem | 15372::LEPAGE | Pumping Irony | Thu Mar 14 1991 17:04 | 17 |
| Re:.303
The AC imbalance is believed to be caused by "soft" short between
the AC and DC power supplies. The most likely cause of this short are
small bits of metal in the interface between the spinning and
nonspinning portions of the spacecraft. These bits of metal result in a
high resistance connection between the two electrical buses. Where did
the metal bits come from? They're not too sure. What is the worse thing
that could happen? The two power supplies could totally short out
blowing virtually every fuse in the system. If that happened the
spacecraft would be dead and the mission would be over. What can be
done about it? Not sure but it's being looked into. So far the problem
has not got any worse and if I read the reports correctly, it seems to
be correcting itself.
Drew
|
| 560.305 | Is it THAT bad? | DECWIN::FISHER | Pursuing an untamed ornothoid | Fri Mar 15 1991 12:31 | 10 |
| The first mention of the imbalance came back in note .91 or so, only
a month or 2 after launch. My reading of this is not as serious as
Drew's, although I may have missed something. The claim back when this
started is that the spacecraft is designed to operate all the way
between open and dead short between the A/C or D/C bus and chassis.
Of course if the imbalance indicates something which may eventually
cause a short ACROSS either power supply, we're in trouble.
Burns
|
| 560.306 | GALILEO Update - March 14 | ADVAX::KLAES | All the Universe, or nothing! | Fri Mar 15 1991 14:51 | 76 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/14/91
Date: 15 Mar 91 03:09:20 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
March 14, 1991
As of noon (PST) Thursday, March 14, 1991, the Galileo spacecraft
is 35,365,790 miles from Earth and traveling at a heliocentric speed
of 70,450 miles per hour; distance to the Sun is 106,360,700 miles
(1.15 AU). Round trip light time is 6 minutes, 20 seconds.
A NO-OP command was successfully sent on March 11 to reset the
Command Loss Timer to 240 hours, its planned value for this mission phase.
Commands were sent on March 8 to change the engineering telemetry
map back to a measurement configuration providing greater system
visibility into the AC/DC bus imbalance anomaly. Earlier, the
telemetry map was altered to accommodate last weeks radio frequency
receiver and command detector unit characterization tests.
Another RPM (Retro Propulsion Module) 10-Newton thruster
maintenance flushing activity was performed on March 8. All twelve
thrusters were cleared, except for the P-thrusters, which are used to
perform periodic sun pointing activities. The spacecraft performance
during this operation was normal and thruster temperatures were
similar to those observed on previous activities.
Cruise Science Memory Readouts (MROs) were successfully performed
for the EUV (Extreme Ultraviolet Spectrometer), MAG (Magnetometer) and
DDS (Dust Detector) instruments on March 11; another MAG MRO was also
performed on March 8.
The second of seven planned UVS (Ultraviolet Spectrometer) Lyman
Alpha data collection activities was completed on March 11.
Another USO (Ultra Stable Oscillator) calibration test was
completed on March 14. This test is periodically performed providing
trend information characterizing this downlink frequency source.
The AC/DC bus imbalance measurements exhibited little activity.
The AC imbalance reading fluctuated 2 DN and now reads 45.2 volts; the
DC measurement changed 6 DN and now reads near 10 volts. All other
power-related telemetry and subsystem telemetry are normal. A second
AC/DC bus imbalance special technical review is scheduled to be held
at JPL on March 27. The Review Board, as before, will consist of
personnel from JPL, other NASA centers and selected members of the
standing Galileo Project Review Board.
The German Space Operations Center (GSOC) has reported completion
of internal Ground Data System (GDS) testing of support capabilities
which will be used to support Galileo Cruise Science Operations
starting in September. No major liens were identified in quick look
post test discussions with JPL. A final written test report is
expected from GSOC in the near future. JPL System Engineers have
begun the validation of interface and data products as part of joint
(JPL and GSOC) GDS testing. Joint testing and analysis of results is
currently scheduled to be completed by mid-April.
The TCM-9B (Trajectory Correction Maneuver 9B) design
implementation was approved by the Project on March 12, 1991. The
maneuver will be performed on March 20 using the axial (Z) and lateral
(L) thrusters to impart a delta velocity of about 2.28 meters/sec.
The maneuver sequence final approval meeting is scheduled for March 18
with sequence uplinked to the spacecraft on March 19.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.307 | Problem? What problem? | 15372::LEPAGE | Pumping Irony | Fri Mar 15 1991 14:56 | 11 |
| Re:.305
Burns,
I think we agree; the power supply problem isn't too much of a
bother right now. However, there still exists the possibilty (the worse
case scenario) where the power supplies short out at which point the
spacecraft is dead. If I were a betting man, however, I'd put my money
on the problem not getting that bad :-)
Drew
|
| 560.308 | GALILEO Update - March 18; Gaspra info | ADVAX::KLAES | All the Universe, or nothing! | Tue Mar 19 1991 12:35 | 60 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/18/91
Date: 18 Mar 91 23:19:11 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
March 18, 1991
The Galileo spacecraft will execute a Trajectory Correction
Maneuver (TCM-9B) on Wednesday, March 20, to help aim it for the
first-ever flyby of an asteroid next October. Tomorrow, the TCM-9B
maneuver sequence will be uplinked to the spacecraft. In the maneuver
Galileo will fire its small thrusters on and off during a period
beginning at about 10 AM (PST) and concluding at about 1:30 PM (PST).
The firings will result in a velocity change of about 5 miles per
hour. The maneuver, together with three more planned in July and
October, will shape Galileo's flight path for its flyby of Gaspra in
the main asteroid belt on October 29.
Galileo will be the first spacecraft to fly by an asteroid
when it approaches within about 1,000 miles of the irregularly shaped,
stony lump measuring nearly 15 miles across. During the encounter,
the spacecraft will photograph and collect a wide variety of
scientific data on the asteroid. The spacecraft has an opportunity
for another asteroid encounter with Ida in 1993 en route to its
destination, the giant planet Jupiter and its system of moons.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
From: tholen@uhccux.uhcc.Hawaii.Edu (David Tholen)
Newsgroups: sci.space,sci.astro
Subject: Re: Galileo Update - 03/18/91
Date: 19 Mar 91 01:41:21 GMT
Organization: University of Hawaii
> Galileo will be the first spacecraft to fly by an asteroid when it
> approaches within about 1,000 miles of the irregularly shaped, stony lump
> measuring nearly 15 miles across. During the encounter, the spacecraft will
Probably meant to say 15 kilometers across. The published catalog
of IRAS detections of asteroids shows one successful observation of
Gaspra, and that indicates an effective diameter of 15.5 km. However,
I understand that the latest orbit for Gaspra has shifted its expected
position on the IRAS detectors toward the edge, meaning that the
quality of the measurement is now in question. In addition, Gaspra
has a fairly substantial rotational lightcurve variation, indicating
an elongated shape, and nobody knows at what point in the rotational
lightcurve the IRAS observation was made, so the stated diameter is
rather uncertain. The range of 1,000 miles is correct, so if the true
effective diameter is indeed about 15 km, then Gaspra will slightly
overfill the Galileo camera field of view.
|
| 560.309 | GALILEO Updates - March 20-22 | ADVAX::KLAES | All the Universe, or nothing! | Tue Mar 26 1991 13:55 | 167 |
| From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/20/91
Date: 20 Mar 91 21:36:53 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
March 20, 1991
Today, the Galileo spacecraft is about 36 million miles from
Earth and 110 million miles from the Sun, traveling at a heliocentric
speed of 68,700 miles per hour. Round-trip communication time is 6
minutes, 24 seconds.
Galileo is executing a Trajectory Correction Maneuver to help
shape the flight path for its encounter of the asteroid Gaspra on
October 29. In the maneuver Galileo will fire its small thrusters on
and off during a period beginning at about 10 AM Pacific Standard Time
(PST) and concluding at about 1:30 PM PST. The firings will result in
a velocity change of about 5 miles per hour.
For the rest of the week, the spacecraft will continue with
routine housekeeping activities and readouts of data from science
instruments.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/21/91
Date: 22 Mar 91 01:03:04 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
March 21, 1991
Yesterday, the Galileo spacecraft successfully completed the
TCM-9B (Trajectory Correction Maneuver). Spacecraft performance
throughout the maneuver was normal; preliminary navigation data
indicates an overburn of less than 1 percent. Today, no spacecraft
activities are planned. Tomorrow, activities will be limited to a USO
(Ultra Stable Oscillator) calibration test.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
From: baalke@mars.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 03/22/91
Date: 22 Mar 91 18:02:15 GMT
Sender: news@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory, Pasadena, CA.
GALILEO STATUS REPORT
March 22, 1991
As of noon (PST) Thursday, March 21, 1991, the Galileo spacecraft
is 35,826,900 miles from Earth and traveling at a heliocentric speed
of 68,380 miles per hour; distance to the Sun is 110,452,750 miles
(1.2 AU). Round trip light time is 6 minutes, 24 seconds.
The spacecraft status as of end of day of March 21 was as follows:
o System Power Margin - 75 watts
o Spin Configuration - Dual-Spin - cruise mode
o Spin Rate/Sensor - 3.15 rpm/star scanner
o Spacecraft Attitude Sun Point Angle - approximately
4.5 degrees (leading) plus or minus 0.3 degree
o Downlink telemetry rate/antenna - 40 bps/LGA-1 (Low Gain Antenna)
o General Thermal Control - all temperatures within
acceptable range
o RPM Tank Pressures - all within acceptable range
o Orbiter Science- all powered off except HIC, DDS,
MAG, EUV and UVS
o Probe - powered off, temperatures nominal
o CMD Loss Timer Setting - 240 hours
Time To Initiation - 216 hours
A NO-OP command was successfully sent on March 18 to reset the
Command Loss Timer to 240 hours, its planned value for this mission phase.
Cruise Science Memory Readouts (MROs) were successfully performed
for the EUV (Extreme Ultraviolet Spectrometer), MAG (Magnetometer) and
DDS (Dust Detector) instruments on March 15. The third of seven
planned UVS (Ultraviolet Spectrometer) Lyman Alpha data collection
activities was also completed on March 15.
A 17-degree SITURN was successfully completed on March 15. The
turn resulted in the spacecraft leading the sun by about 10 degrees;
spacecraft performance throughout this activity was normal.
The spacecraft successfully completed its first HGA (High Gain
Antenna) correct activity while in celestial cruise mode; spacecraft
performance was normal and no unexpected events were observed.
The TCM-9B (Trajectory Correction Maneuver) sequence was sent to
the spacecraft on March 19. Prior to maneuver execution, the EPD
(Energetic Particle Detector) was powered on and stepped from sector
position 4 to 0, the minimum contamination location. Subsequent to
the maneuver, the EPD was repositioned back to Sector 4.
The TCM 9-B was performed on March 20 and consisted of one
portion employing a single positive Z burn segment followed by two
lateral burn segments. Spacecraft performance throughout the manuever
activity was normal. RPM (Retro Propulsion Module) pressures and
temperatures were near predicted levels; the regulator remained closed
and thruster temperature profiles observed were similar to other
burns. However, after the final lateral burn, the regulator opened at
about 17.1 bar, near the predicted level. The spacecraft experienced
some small attitude and spin rate change (1.5 mrad and ..033 rpm,
respectively) during the positive Z burn. No sequence commanded
attitude correction was made but a spin correction was made. At the
end of the lateral burn segment, sequence planned attitude and spin
rate corrections were made. Preliminary radio navigation data
indicates the positive Z burn was about 1 percent high; the lateral
burn was also high but estimated to be less than 0.5 percent. Better
trajectory data will be available after more tracking data is collected.
The AC/DC bus imbalance measurements exhibited some activity.
The AC imbalance reading fluctuated about 2 DN and now reads 45.2
volts; the DC measurement dropped from 10 volts to 1.5 volts (82 DN)
on March 15 and has subsequently gradually increased and now reads
about 5.5 volts. The large drop occurred more than an hour after a
spacecraft thruster firing. Nearly coincident with bus imbalance
change, the -X RTG temperature transducer measurement also changed.
Other power-related telemetry and subsystem related telemetry are
normal. Throughout the maneuver activity on March 20, the AC and DC
bus imbalance measurements were fairly stable and fluctuated about 1-2 DN.
Commands were sent on March 20 to power off the UVS supplemental
heater to provide more power margin for RPM thermal control. Additionally,
Delay Action Commands (DACs) were sent to power off the UVS heater again
on April 10 after it is turned on by stored sequence control.
The Ground Data System (GDS) Test Plan for Joint JPL and German
Space Operations Center (GSOC) testing was published and formal
interface testing has started. The JPL Data Management Team (DMT) has
received for validation a sample Experiment Data Record (EDR) produced
by GSOC from data received from the Galileo spacecraft during a post
Earth demonstration track with the German Weilheim Tracking Station.
GSOC will later merged this data with DSN (Deep Space Network) data
supplied by the DMT and a set of test Low Rate Science (LRS) Fields
and Particles (F&P) EDRs and Supplementary EDRs (SEDRs) will be
generated for final validation by the Principal Investigators. Other
interface products are also being systematically produced, transferred,
and validated as part of the interface testing currently in process.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.310 | More Gaspra information | ADVAX::KLAES | All the Universe, or nothing! | Tue Mar 26 1991 13:56 | 154 |
| From: 17001_1511@uwovax.uwo.ca
Newsgroups: sci.space
Subject: Galileo asteroid imaging
Date: 20 Mar 91 17:15:24 GMT
The question about Galileo imaging of asteroid 951 Gaspra prompts
this reply:
In November 1990 I spoke to Joe Veverka at Cornell about this - he
is planning the observation sequences. The range is about 1000 km (not
miles) but is not known very precisely because of uncertainty over the
asteroid ephemeris (especially its range from Earth). Lightcurves
suggest about a 9 hour period if I recall correctly (see a recent
ICARUS paper), so about 4.5 hours before closest approach the view is
of the side which will not be seen close up, assuming a low latitude
approach (and we know very little about the axis orientation). Those
images will resolve few features but will give an idea of shape. At
closest approach the asteroid should overflow a single frame, as
Miranda did with Voyager 2 in 1986, so a mosaic will be needed for
full coverage. The problem is with the image motion compensation - the
rate depends on the exact flyby distance and there seems little chance
it will be well known in time. The strategy will be to take as many
redundant frames as possible with different image motion compensation
rates, in order to get at least a few frames with very little smear.
At least, that was the plan in November. The lightcurve variations
suggest a complex shape, and the images may be quite dramatic.
Phil Stooke,
Department of Geography,
University of Western Ontario,
London, Ontario, Canada N6A 5C2
From: tholen@uhccux.uhcc.Hawaii.Edu (David Tholen)
Newsgroups: sci.space
Subject: Re: Galileo asteroid imaging
Date: 21 Mar 91 22:49:10 GMT
Organization: University of Hawaii
17001_1511@uwovax.uwo.ca writes:
> In November 1990 I spoke to Joe Veverka at Cornell about this - he is
> planning the observation sequences. The range is about 1000 km (not miles)
> but is not known very precisely because of uncertainty over the asteroid
> ephemeris (especially its range from Earth).
I would normally consider Veverka a very reliable source of
information, but if your conversation was in November, then it
preceded the team meeting on December 6 that resulted in the final
decision. Mike Belton, the imaging team leader, gave me the 1600 km
(or about 1000 miles) figure. We've been working on the asteroid's
ephemeris. I'd have to ask Don Yeomans for a definitive answer (and I
already have), but my guess is that we probably know the asteroid's
location to perhaps 50 km, maybe as bad as 100 km, at the present time.
> Lightcurves suggest about
> a 9 hour period if I recall correctly (see a recent ICARUS paper), so
> about 4.5 hours before closest approach the view is of the side which will
> not be seen close up, assuming a low latitude approach (and we know very
> little about the axis orientation).
Just a tad over 7 hours (and that is authoritative -- I've observed
the lightcurve, and, in fact, am currently at Mauna Kea to do another,
starting tonight, weather permitting). The intent is to have a low
latitude approach, and the trajectory chosen in December was based on
the best information available at the time. I think we know more
about the axis orientation than you've suggested, and our paper will
be submitted within days. If our run this weekend is successful, we
should have a confirmation in hand of our prediction of a high obliquity.
> Those images will resolve few features
> but will give an idea of shape. At closest approach the asteroid should
> overflow a single frame, as Miranda did at Uranus, so a mosaic will be needed
> for full coverage. The problem is with the image motion compensation - the
> rate depends on the exact flyby distance and there seems little chance it will
> be well known in time. The strategy will be to take as many redundant frames
> as possible with different image motion compensation rates, in order to get
> at least a few frames with very little smear. At least, that was the plan in
> November. The lightcurve variations suggest a complex shape, and the images
> may be quite dramatic.
Complex? I'd prefer the term "asymmetric". More egg-shaped than the
usual tri-axial ellipsoids used for modeling lightcurves. I'm
confident that the images we do get will be dramatic, but I'm biased.
We will probably also get a lot of blank frames, because the asteroid's
location won't be known that well, but we're working on it.
From: moersch@theory.tn.cornell.edu (Jeff Moersch)
Newsgroups: sci.space
Subject: Re: Galileo asteroid imaging
Date: 22 Mar 91 08:15:13 GMT
Sender: news@batcomputer.tn.cornell.edu
Organization: Cornell Theory Center
In article <1991Mar20.121525.8853@uwovax.uwo.ca>
17001_1511@uwovax.uwo.ca writes:
>be well known in time. The strategy will be to take as many redundant frames
>as possible with different image motion compensation rates, in order to get
>at least a few frames with very little smear. At least, that was the plan in
>November. The lightcurve variations suggest a complex shape, and the images
As of the February imaging team meeting at Caltech, the current strategy for
closest approach is not to have totally redundant frames. The problem is that
the error ellipse for Gaspra's location is very large (larger than an image
frame), so if the frames were all pointed exactly alike, they could all
completely miss the asteroid. To deal with this, there is a mosaic sequence
planned which will cover the entire ellipse (I forget to how many sigma).
Jeff Moersch
moersch@theory.tn.cornell.edu
From: tholen@uhccux.uhcc.Hawaii.Edu (David Tholen)
Newsgroups: sci.space
Subject: Re: Galileo asteroid imaging
Date: 23 Mar 91 02:29:16 GMT
Organization: University of Hawaii
>> The lightcurve variations suggest a complex shape, and the images
>> may be quite dramatic.
>
> Complex? I'd prefer the term "asymmetric". More egg-shaped than the usual
> tri-axial ellipsoids used for modeling lightcurves. I'm confident that the
> images we do get will be dramatic, but I'm biased. We will probably also
> get a lot of blank frames, because the asteroid's location won't be known
> that well, but we're working on it.
Just to briefly followup on my earlier response, the 1988 lightcurve
published by DiMartino could be considered complex. However, they did
not mention in their paper that the lightcurve was obtained within a
few degrees of the galactic center. I am confident that some of the
fine-scale "complex" structure seen in their lightcurve is, in fact,
due to field star contamination. More recent lightcurves are
substanitally smoother in appearance, though asymmetric.
From: tholen@uhccux.uhcc.Hawaii.Edu (David Tholen)
Newsgroups: sci.space
Subject: Re: Galileo asteroid imaging
Date: 23 Mar 91 02:31:52 GMT
Organization: University of Hawaii
loren@ingrid.llnl.gov (Loren Petrich) writes:
> I am not sure if it would be practical to do it, but it might
> be possible to take pictures of Gaspra from a distance, before closest
> encounter, to assist in targeting the asteroid.
Spacecraft navigation will be done, but range information is still the
hardest to get, so triangulation using ground-based observations is
also being pursued vigorously.
|
| 560.311 | GALILEO went into safing mode | ADVAX::KLAES | All the Universe, or nothing! | Fri Mar 29 1991 12:15 | 52 |
| From: clarinews@clarinet.com
Newsgroups: clari.tw.space
Subject: Galileo goes into 'hibernation'
Date: 28 Mar 91 22:39:57 GMT
PASADENA, Calif. (UPI) -- A mysterious computer glitch put
NASA's $1.5 billion Galileo Jupiter probe into an electronic state of
hibernation earlier this week, but engineers said Thursday the
spacecraft was not damaged and remained healthy.
Galileo, the most advanced interplanetary probe ever built, is
in an elliptical orbit around the sun that will bring it back to Earth
next year for a gravitational boost toward distant Jupiter. The
spacecraft is scheduled to slip into orbit around the giant planet in
1995 for two years of unprecedented close-range study.
Since launch from the shuttle Atlantis on Oct. 18, 1989,
Galileo has performed virtually flawlessly, flying once past Venus and
once past Earth for velocity-boosting flybys.
But Tuesday at 6:10 a.m. PST, Galileo went into ``safing
mode,'' an automatic emergency procedure ordered by the probe's flight
computers when a problem is detected. On one other occasion the
spacecraft entered safing mode and was successfully restored to full
operation.
In the event this week, Galileo's electronic brain shut down
the craft's science instruments, switched to a low-speed data
transmission and went into a full spin. Prior to the event, only part
of the spacecraft was spinning with one section held stationary.
Galileo also conducted a maneuver to orient itself properly
with respect to the sun, a procedure that is automatically carried out
every 12 hours in safing mode.
``According to the flight team, data from Galileo show that
the incident was caused when one of the spacecraft's two...computers
detected a problem with itself, prompting it to take itself off-line,''
JPL said in a statement. ``The other computer continued to function
properly and carried out all intended operations.
``The cause of the problem in the computer is unknown, but has
been confirmed to have been a transient signal of some kind. There is
no evidence of any permanent damage to any hardware on board the
spacecraft.''
Engineers said Galileo would be back into full operation by
the time the next set of computer commands is radioed to the craft in
late April. The glitch will delay the unfurling of Galileo's main
antenna, originally planned for April 10, but the milestone event is
expected to take place before April 25.
|
| 560.312 | GALILEO Update - April 4 | ADVAX::KLAES | All the Universe, or nothing! | Mon Apr 08 1991 13:27 | 33 |
| From: yee@trident.arc.nasa.gov (Peter E. Yee)
Newsgroups: sci.space
Subject: Galileo Status for 04/04/91 (Forwarded)
Date: 6 Apr 91 00:28:20 GMT
Sender: usenet@news.arc.nasa.gov (USENET Administration)
Organization: NASA Ames Research Center, Moffett Field, CA
GALILEO STATUS REPORT
April 4, 1991
Operations are proceeding smoothly to bring Galileo out of
safing mode, flight controllers report.
The spacecraft entered safing mode Tuesday, March 26, after
an unexpected transient signal caused one of Galileo's two redundant
Command & Data Subsystem computers to detect an error in itself. In
safing mode, Galileo turns off science instruments, changes its spin
configuration, slows the bit rate of data it sends to Earth and
automatically performs maneuvers on a regular basis to orient itself
to the Sun. The spacecraft responded exactly as intended, the flight
team noted.
Project officials said they plan to bring the spacecraft out
of safing mode gradually so that it is ready to execute the next major
sequence of commands to be sent to Galileo on April 25.
Current plans call for Galileo to unfurl its high-gain
antenna on Thursday, April 11.
Today Galileo is 37 million miles from Earth and 119 million
miles from the Sun, traveling at a heliocentric speed of 64,400 miles
per hour. Round-time communication time is 6 minutes, 33 seconds.
|
| 560.313 | GALILEO Update - April 10 | ADVAX::KLAES | All the Universe, or nothing! | Tue Apr 16 1991 15:09 | 48 |
| From: yee@trident.arc.nasa.gov (Peter E. Yee)
Newsgroups: sci.space
Subject: Galileo Status for 04/10/91 (Forwarded)
Date: 11 Apr 91 23:39:23 GMT
Sender: usenet@news.arc.nasa.gov (USENET Administration)
Organization: NASA Ames Research Center, Moffett Field, CA
GALILEO STATUS REPORT
April 10, 1991
Galileo will unfurl its 16-foot-diameter main communications
antenna Thursday, setting the stage for transmission of high volumes
of science data when Galileo flies by the asteroid Gaspra later this
year.
The umbrella-like high-gain antenna, made of metal mesh, has
been stowed behind a sun shield since Galileo's launch in October
1989, to avoid heat damage while the spacecraft flew closer to the sun
than the orbit of Earth.
Using one of its low-gain antennas, Galileo generally
transmits data at up to 1,200 bits per second (bps). With the
high-gain antenna, Galileo will be able to transmit at up to 134,000
bps (the equivalent of about one television picture each minute)
across hundreds of millions of miles of space.
Commands to unfurl the antenna will be issued by Galileo's
computers at about 12:50 p.m. Pacific Daylight Time on Thursday, April
11. The unfurling will be completed in less than 10 minutes. The
first radio transmission over the antenna will be sent May 6.
Galileo will use the high-gain antenna during its flyby of
the asteroid Gaspra, at a distance of some 255 million miles from
Earth, on October 29. The spacecraft will be some 580 million miles
from Earth when it arrives at its final destination, the giant planet
Jupiter, in December 1995.
In other events this week, flight controllers on Tuesday,
April 9, returned Galileo to its normal "dual-spin" configuration, in
which part of the spacecraft spins and part remains fixed in relation
to space. Galileo will be fully configured for normal operations by
the time the next major sequence of commands is sent to the spacecraft
April 25.
Today Galileo is 37 million miles from Earth and 122 million
miles from the sun, traveling at a heliocentric velocity of 62,800 miles
per hour. Round-trip communication time is 6 minutes, 40 seconds.
|
| 560.314 | Problems with GALILEO's main antenna | ADVAX::KLAES | All the Universe, or nothing! | Tue Apr 16 1991 15:10 | 139 |
| From: clarinews@clarinet.com (WILLIAM HARWOOD, UPI Science Writer)
Newsgroups: clari.tw.space
Subject: Possible trouble with Galileo antenna
Date: 12 Apr 91 23:56:05 GMT
Worried engineers Friday pored over data from NASA's $1.5 billion
Galileo Jupiter probe that indicates its critical 16-foot main antenna
may have failed to unfold properly as planned Thursday.
Failure of the umbrella-like 16-foot ``high-gain'' antenna to open
fully would be a major setback to the Galileo project, severely limiting
the speed at which data about Jupiter could be transmitted to Earth and
sharply reducing the number of photographs that could be beamed back to
the inner solar system.
But project manager William O'Neil at NASA's Jet Propulsion
Laboratory in Pasadena, Calif., said by telephone Friday engineers are
optimistic about coaxing the antenna open if, in fact, it did not deploy
fully on Thursday as planned.
``The data that we have at this point does suggest there has been
some degree of deployment, or unfurling,'' O'Neil said. ``We can't even
rule out the thing is entirely deployed and just didn't get to the full
stop.''
But, he said: ``That's not a high likelihood. The more likely thing
is we have some partial deployment condition. What we're doing is
analyzing our data to understand that better.''
JPL spokesman Frank O'Donnell said late Friday engineers would delay
taking any action to correct the possible problem at least through the
weekend so they could have ``more time to sift through the data.''
The Galileo probe was launched from the space shuttle Atlantis on
Oct. 18, 1989. It is scheduled to slip into orbit around Jupiter in 1995
to study the giant planet and its many moons in unprecedented detail.
In addition, a small probe will be dropped into Jupiter's atmosphere
for the first direct measurements of its structure and composition.
At Jupiter's great distance from the Earth -- the planet is roughly
500 million miles from the sun -- a large radio antenna is needed to
achieve the signal strength necessary to transmit high-speed data. The
high-gain antenna is capable of transmitting 134,000 bits of data per
second, the equivalent of one black-and-white image per minute.
The spacecraft also is equipped with two smaller antennas that
transmit at much lower speeds. Without the use of the high-gain antenna,
Galileo's ability to transmit data-packed photographs and other
information would be severely restricted.
The dish-shaped antenna was folded up like an umbrella at launch. It
was designed to open using small motors that turn a screw mechanism. The
screw, in turn, pushes against a ring that forces the ribs of the
antenna to open.
``The spacecraft issued the commands to deploy the antenna (Thursday)
and all the commands were issued as planned,'' said O'Neil. ``However,
we saw immediately in our telemetry the motors were drawing considerably
higher current than expected.
``More importantly, the micro-switches on the mechanism did not
activate to indicate the antenna was fully deployed. As of this moment,
we are still analyzing all the data to try to determine to what extent,
if at all, the antenna has deployed.''
Built at the Jet Propulsion Laboratory, Galileo is unique among
spacecraft launched to date in that it features a ``dual spin'' design
in which one section of the craft rotates about its long axis while
another section is held stationary.
The antenna is located on the spinning section. Had it unfolded
fully, the spacecraft's spin would have decreased, much like a spinning
ice skater slows down by moving his or her arms away from the body.
``We did see a spin decay, but not as much as we should have seen,''
O'Neil said.
Data from the probe does not indicate that the motors or any other
systems were damaged and there is nothing to suggest engineers cannot
simply turn the motors back on for another try. But before that happens,
they want to thoroughly study the data to make sure they do not
inadvertently cause any damage.
In a worst-case scenario, O'Neil said data from the atmospheric entry
probe still could be transmitted to Earth using the low-data-rate
system. The same system could be used to send back photographs, but only
``at a snail's pace compared to what we had planned to do.''
The Galileo orbiter stands 30 feet tall and weighs about 5,240
pounds, including about 2,039 pounds of rocket fuel.
The upper, spinning section of the spacecraft consists of the high-
gain antenna, two 124-pound nuclear generators, the propulsion system,
computers, radios and a 36-foot boom carrying instruments that measure
fields and particles.
The non-spinning section carries Galileo's television cameras,
infrared and ultraviolet instruments to study the composition of
Jupiter's atmosphere and a ``photopolarimeter'' designed to measure how
sunlight is absorbed and reflected by the atmosphere.
From: clarinews@clarinet.com
Newsgroups: clari.tw.space
Subject: Problem with Galileo antenna appears more likely
Date: 15 Apr 91 22:43:58 GMT
PASADENA, Calif. (UPI) -- NASA officials have become more
certain that a critical antenna on the $1.5 billion Galileo Jupiter
probe failed to fully extend and are studying how to correct the
problem, a spokesman said Monday.
``We feel that we have a better understanding of what kind of
condition the antenna is in now,'' said Frank O'Donnell of NASA's Jet
Propulsion Laboratory, which operates the probe.
``It very probably is partially deployed. We can't say with total
certainty but when we look at more data they all point to it being
partially deployed,'' he said.
Engineers will analyze the data for several more days and will
probably attempt to fully deploy the antenna again next week, he said.
Failure of the umbrella-like, 16-foot ``high-gain'' antenna to open
fully would be a major setback to the Galileo project, severely limiting
the speed at which data about Jupiter could be transmitted to Earth and
sharply reducing the number of photographs that could be beamed back to
the inner solar system.
The Galileo probe was launched from the space shuttle Atlantis on
Oct. 18, 1989. It is scheduled to slip into orbit around Jupiter in 1995
to study the giant planet and its many moons in unprecedented detail.
In addition, a small probe will be dropped into Jupiter's atmosphere
for the first direct measurements of its structure and composition.
At Jupiter's great distance from the Earth -- the planet is roughly
500 million miles from the sun -- a large radio antenna is needed to
achieve the signal strength necessary to transmit high-speed data. The
high-gain antenna is capable of transmitting 134,000 bits of data per
second, the equivalent of one black-and-white image per minute.
The spacecraft also is equipped with two smaller antennas that
transmit at much lower speeds. Without the use of the high-gain antenna,
Galileo's ability to transmit data-packed photographs and other
information would be severely restricted.
The dish-shaped antenna was folded up like an umbrella at launch. It
was designed to open using small motors that turn a screw mechanism. The
screw, in turn, pushes against a ring that forces the ribs of the
antenna to open.
The 30-foot-tall, 5,240-pound craft has a ``dual spin'' design in
which one section rotates about its long axis while another section is
held stationary. The antenna is located on the spinning section.
Had the antennas unfolded fully as instructed last Thursday, the
probe's spin would have decreased, much like a spinning ice skater slows
down by moving his or her arms away from the body. The spin failed to
decay as much as it should have, officials said.
Data from the probe does not indicate that the motors or any other
systems were damaged and there is nothing to suggest engineers cannot
simply turn the motors back on for another try. But before that happens,
they want to thoroughly study the data to make sure they do not
inadvertently cause any damage.
In a worst-case scenario, data from the atmospheric entry probe still
could be transmitted to Earth using the low-data-rate system. The same
system could be used to send back photographs, but at only a fraction of
the speed as had been planned.
|
| 560.315 | | DECWIN::FISHER | Pursuing an untamed ornothoid | Thu Apr 18 1991 20:00 | 4 |
| First Hubble, then GRO, now Galileo. Do we need a new "deployable structures"
contractor? :-(
Burns
|
| 560.316 | | 25415::MAIEWSKI | | Fri Apr 19 1991 00:02 | 8 |
| Boy, not much news here. I wonder if the folks at JPL are all hiding
somewhere.
Unfolding things and opening doors seems to be two of the things that gives
NASA the most problems. Have you ever had problems opening an umbrella or
the front door to your house? Talk about "we can put a man on the moon but ...".
George
|
| 560.317 | another case | 2319::SAUTER | John Sauter | Fri Apr 19 1991 09:41 | 3 |
| Didn't Skylab also have trouble opening something? (I think it was one
of the solar panels.)
John Sauter
|
| 560.318 | Skylab Info | 2631::DAHL | Tom Dahl, CDMS | Fri Apr 19 1991 10:13 | 10 |
| RE: <<< Note 560.317 by 2319::SAUTER "John Sauter" >>>
> Didn't Skylab also have trouble opening something? (I think it was one
> of the solar panels.)
Skylab was damaged during atmospheric flight during launch. One of the body-
mounted solar panels was torn away, the other was jammed by metal bands that
got wrapped around it. The first crew conducted an EVA to cut the obstructing
metal and the panel popped open.
-- Tom
|
| 560.319 | Galileo Status Report - 04/17/91 | PRAGMA::GRIFFIN | Dave Griffin | Fri Apr 19 1991 20:55 | 34 |
| GALILEO STATUS REPORT
April 17, 1991
Flight controllers are continuing detailed analysis of
a problem that occurred during the unfurling of the Galileo
spacecraft's main communications antenna Thursday, April 11.
Commands to unfurl the 16-foot-diameter umbrella-like
antenna were issued by Galileo's computers on schedule at about
12:50 p.m. Pacific Daylight Time on April 11. The action was to
be completed in less than 10 minutes. Data received from
Galileo, however, suggest that the antenna partially deployed,
but did not open fully.
Engineers will continue analysis of data sent by
Galileo during the deployment attempt before taking any further
action on the spacecraft. Project officials emphasize that the
deployment difficulty poses no immediate problems for the
spacecraft, which otherwise is functioning properly.
The high-gain antenna -- a modified version of the
design used in NASA's Earth-orbiting Tracking & Data Relay
Satellites -- has been stowed behind a sun shield since Galileo's
launch in October 1989 to avoid heat damage while the spacecraft
flew closer to the sun than the orbit of Earth. Unfurling of the
antenna is necessary for Galileo to send scientific data to Earth
at much higher rates over greater distances than it can with the
low-gain antennas it has used since launch.
Today Galileo is 38 million miles from Earth and 127
million miles from the sun, traveling at a heliocentric velocity
of 61,000 miles per hour. Round-trip communication time is 6
minutes, 50 seconds.
|
| 560.320 | Galileo Antenna Deployment Studied by NASA | PRAGMA::GRIFFIN | Dave Griffin | Fri Apr 19 1991 20:56 | 70 |
| RELEASE: 91-59
4/19/91
Intensive analysis of the problem that prevented
deployment of the Galileo spacecraft's high-gain antenna is
continuing at NASA's Jet Propulsion Laboratory (JPL), Pasadena,
Calif. A "tiger team" of specialists from a variety of
engineering disciplines -- including industry representatives --
has been assembled to study the problem and how to correct it.
Galileo Project officials say they expect to carry out
considerably more analysis and ground tests before determining a
date to make another deployment effort. The deployment
difficulty poses no immediate problems for the spacecraft, which
otherwise is functioning properly.
The problem arose Thursday, April 11, 1991, when commands
to unfurl the umbrella-like antenna were issued by Galileo's
computers. The deployment action -- very similar to opening a
conventional umbrella -- was expected to be concluded in less
than 3 minutes.
Data from Galileo, however, indicate that the antenna
unfurled partially but did not completely unfold. One side of
the antenna appears to be deployed more fully than the other
side, suggesting that some restriction may be affecting a portion
of the antenna's movement.
Data that the JPL team has been studying include readings
from the spacecraft's sun sensor and from its spin detectors,
which offer engineers information on the current state of the
antenna. In addition, data from Galileo's power system provide
details on how the deployment attempt proceeded and possible
clues on the nature of the restriction. Engineers say that
continued analysis of the data -- and tests of identical antenna
equipment on the ground -- are important to avoid any action that
could damage onboard equipment.
The 16-foot-diameter, high-gain antenna -- a modified
version of the design used in NASA's Earth-orbiting Tracking &
Data Relay Satellites -- has a surface made of gold-plated
molybdenum wire woven into a mesh. The mesh is stretched across
18 graphite-epoxy ribs and connected with quartz cords.
The antenna has been stowed behind a sun shield since
Galileo's launch in October 1989 to avoid heat damage while the
spacecraft flew closer to the sun than the orbit of Earth.
The antenna deployment mechanism is driven by a set of
redundant motors which turn a worm gear. This gear pushes a nut
connected to levers which spread the antenna's ribs, much as an
umbrella is opened.
Unfurling of the antenna will enable Galileo to send
scientific data to Earth at much higher rates over greater
distances than it can with the two low-gain antennas it has used
since launch.
Project officials say Galileo will still conduct its
planned flyby of the asteroid Gaspra on October 29 even if the
antenna is partially deployed. In that event, pictures and other
data would be stored on the spacecraft's onboard tape recorder
and relayed to the ground when Galileo approaches for its flyby
of Earth in December 1992.
JPL manages the Galileo Project for NASA's Office of
Space Science and Applications.
- end -
|
| 560.321 | | 25415::MAIEWSKI | | Fri Apr 19 1991 21:28 | 8 |
| I wonder if they could launch a small Satellite with a camera and inject it
into Galileo's orbit to observe the problem when it makes it's fly by in 2
years? It would have to be light and use most of it's weight for fuel and
perhaps do some sort of tricky lunar flyby to catch up but it might work.
If it had a small arm, it might be able to fix the problem.
George
|
| 560.322 | | PRAGMA::GRIFFIN | Dave Griffin | Mon Apr 22 1991 10:19 | 7 |
| Very dramatic, but I wouldn't pay for it.
It would be less risky, and nearly as expensive to build Galileo II
and launch it after Galileo I arrives at Jupiter (maybe we'll have
a decent launch vehicle by then).
- dave
|
| 560.323 | ?? status | 3149::BIRO | | Mon Apr 22 1991 10:22 | 21 |
| does anyone know if they have made any measurement on
the gain of the antenna to see if it is truely not
fully deployed. It maybe a false signal, and a gain
test could tell the true story. I assume that is why
they are looking at the sollar pannels and sun sensors
to see if there are any unexpected 'shadows'.
The cammer Idea is a neat idea, but I wonder if the
on board cammer could foucus that colse...
They could take 'images' from the 'air'/'ground' but it would be
to late to make a decsion to park it in earth orbit
for repair. But I guess any parking orbit would require
the satellite mission to be aborted and the satellite return
to earth.
cheers john
|
| 560.324 | | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Mon Apr 22 1991 11:31 | 7 |
| There already is a camera in orbit that is quite capable of imaging
Galileo on its way back to Earth, namely Hubble.
But yes, gain measurements should be possible now. And after all, that
is what really matters.
gary
|
| 560.325 | What goes wrong with umbrellas if they're not in the windd! | DECWIN::FISHER | Pursuing an untamed ornothoid | Mon Apr 22 1991 14:54 | 21 |
| re gain measurements: I would guess that the gain would be nearly an
all-or-nothing kind of thing. If the antenna were unfolding about its
axis so that partial deployment meant that the panels were ok around
some of the cicumfrence but not all, that would be one thing. However,
if it opens like an umbrella, it does not form its proper parabola
shape till it is fully open. That means that waves originating from
what is supposed to be the parabola's focus would probably never be
seen by Earth; they would be reflected in all different directions.
That is not to say it should not be tried...if the parabola shape was
close, they might find something out.
Actually another point: if the reflector is out extended, I wonder if
the loading on the transmitter might be wrong, and thus burn it out if
it attempts to transmit.
They might be better off doing a gain check with a very high power
transmission from earth to the hi-gain receiver.
Burns
|
| 560.326 | | 25415::MAIEWSKI | | Mon Apr 22 1991 15:17 | 5 |
| I've gotta believe they tried most of these things. What I find surprising
is the awsome silence from both JPL and from the press who usually likes
to jump all over NASA about this sort of thing.
George
|
| 560.327 | My two cents | 15372::LEPAGE | Welcome to the Machine | Mon Apr 22 1991 15:43 | 16 |
| Just to throw in my two cents worth on this subject, I'm concerned
about the apparent failure of the high gain antenna to fully deploy but
all is not lost yet. From what I heard it is partially (and
asymetricly) deployed right now. The reason that they stopped
deployment is that the motors were drawing more current than they
should have and it was taking longer than it should to deploy the HGA.
All it might take is to start the motors again or maybe the spin rate
could be increased a bit to help things or maybe the spacecraft will
have to be jostled a bit to shake something loose. Whatever the
solution, it is prudent to thoroughly study the problem and make the
correct fix. I want to wait and see what happens before I jump all over
JPL and or NASA and I would like to think everyone else including the
press will do the same.
Drew
|
| 560.328 | | DECWIN::FISHER | Pursuing an untamed ornothoid | Tue Apr 23 1991 13:28 | 5 |
| Good point, Drew. There are a lot of things yet to do. Slow the spin, increase
the spin, retract the antenna (wonder if the moters have a reverse command),
etc etc.
Burns
|
| 560.329 | AW&ST Report on Galileo Antenna Problem | LEVERS::HUGHES | TANSTAAFL | Tue Apr 23 1991 21:43 | 93 |
|
April 22, 1991
Copied without permision from Aviation Week and Space Technology
IMPROPER ANTENNA DEPLOYMENT THREATENS GALILEO JUPITER MISSION
Michael A. Dornheim/Pasadena, Calif.
Engineers at NASA's Jet Propulsion Laboratory here have determined
that the high gain antenna on the Galileo spacecraft en route to Jupiter
opened less than halfway before the deployment mechanism became stuck
somehow. This antenna is temporarily useless.
Project officials are optimistic that the high-gain antenna (HGA)
will eventually be freed, and do not need to open it immediately. The
spacecraft is healthy, and communications remain good with its low-gain
antennas. However, if high-speed communications are not available at
Jupiter, most of the orbiter science data will be lost.
The first practical use of the HGA is to be this October when
Galileo encounters the Gaspra asteroid, though much of the data could be
stored on tape and relayed at high rate via the low gain antenna during
the next Earth encounter in December, 1992. From there, the spacecraft
ascends directly to meet Jupiter in December, 1995 (AW&ST Oct 9, 1989,
p.69).
The cause of the Apr. 11 jam has not been determined yet, but
possibilities include inadvertently exposed adhesive tape sticking to
something else, and the mesh that forms the antenna dish becoming
entangled or stuck (AW&ST Apr.15, p.15).
A Sun shade was added next to the folded antenna tips late in the
Galileo program but tests show the deployment drive should have enough
force to rip through a loose tip shade insulation blanket.
The HGA has 18 graphite-epoxy ribs that open like an umbrella,
stretching the gold-plated molybdenum wire mesh between them. The ribs
are covered with thermal blankets attached by double-sided adhesive
tape, with single-sided tape covering any exposed double-sided tape. Tie
points in the mesh shaping cord are covered with a spot of epoxy glue,
and this is also a possible cause for the failure.
The spare flight antenna was deployed incrementally here after the
incident and exposed adhesive tape caused two ribs to stick together for
several minutes. This is a possible cause of the spacecraft problem,
according to William J. O'Neil, JPL Galileo project manager. The spare
HGA was damaged during qualification testing and was not refurbished to
the high standards of the spacecraft antenna, he said.
Each rib is pivoted at the base, where it is connected by a springy
pushrod to a central ring. A ballsccrew moves the ring along the axis of
the antenna, pressing the pushrods against the bottom of the ribs and
levering them open. The ring moves until the pushrods go over center,
locking the ribs open at 68 deg. of rotation.
Deployment normally takes under 3 min. before microswitches on the
ballscrew mechanism shut off the dual drive motors. But on Apr. 11 the
motors were shut off after 8 min. by a software timer, and motor current
telemetry indicates they ran normally for about the first 17 sec., or 7
deg of rib rotation, then slowed until they stalled at about 50 sec. The
motors can be stalled for 15 min. with no harm.
One of the ribs partially obscured a Sun sensor behind the antenna
indicating it was between 34 and 40 deg of deployment. By integrating
the motor current to determine the ring position, engineers estimated
the HGA had a lopsided deployment, with the opposite ribs at about 17
deg. and the ring bending the ballscrew.
The degree of HGA opening matches the change in spin rate seen in
Galileo. Spacecraft wobble is within normal limits.
The antenna is made by Harris Corp. and is similar to ones used on
the NASA/TRW tracking and data relay satellites. There have been no
antenna unfurling problems with TDRS, a TRW official said.
Engineers are modeling the loads on the mechanism, and plan further
tests on the spare antenna. A concern is that the ballscrew might be
snapped by the asymmetry. The earliest attempt to drive the antenna
again would be at the end of April.
If near-term efforts do not succeed, the spacecraft may be oriented
to a different thermal attitude to see if hot or cold temperatures free
the mechanism. This has cured some deployment problems on other
spacecraft.
Thought is already being given to options available if the antenna
repeatedly fails to open. One idea is to build a light-weight radio
relay spacecraft and launch it with a powerful booster into direct
ascent to Jupiter, where it would arrive with or after Galileo. Galileo
already demonstrated it can transmit at the maximum 134 kilobits/sec
rate with the low-gain antenna to nearby receivers when it sent Earch
and Moon imagry during the Earth flyby last December.
|
| 560.330 | | DECWIN::FISHER | Pursuing an untamed ornothoid | Mon Apr 29 1991 14:52 | 5 |
| The comsat idea hit the news over the weekend...CNN mentioned it with no details.
This is a neat idea, but I can't imagine it getting done in time, especially
if they would need it for the penetrator, which doesn't have much timing leaway!
Burns
|
| 560.331 | | 25415::MAIEWSKI | | Mon Apr 29 1991 16:04 | 11 |
| I believe that the current thinking is that the glue that holds the antenna to
the spar may have spread and may be preventing the thing from deploying. Two
possible solutions would be to turn away from the sun to cool the glue or to
turn toward the sun to cook the glue, either of which may do the trick if the
glue is really causing the trouble.
At least they have a long time to work on the problem. It could have been
much worse if the thing wasn't scheduled to open until a week before arriving
at Jupiter.
George
|
| 560.332 | No info, so let's speculate! | DECWIN::FISHER | "I am NOT a Merry Man"--Worf | Thu May 02 1991 14:46 | 31 |
| No info! Aaagh! This is excruciating!
Seriously, I suppose (hope!) that the folks at JPL that normally send out the
status reports are all very busy working on the Galileo antenna problem.
Any interesting speculation going on in sci.space?
I'm really intrigued by the comsat idea, but I'm wondering if anyone has had
practical ideas or if it is just a wild comment that got picked up by AvWeek.
It would seem to me, for example, that there is nothing in the current inventory
of comsats that would be even vaguely useful. They are all solar powered, and
intended to send and receive in quite specialized patterns.
I would think that the closest existing thing that could be used would be
the engineering model of Galileo itself with most of the science stuff ripped
out...just the bus. (Of course, someone will say that well, we have this added
hunk of hardware we are going to put in orbit around Jupiter...let's load it
up to gain the maximum advantage).
Is this AT ALL practical? What about all the earlier words about there not
being any more material to make RTGs with?
What about Cassini? Is there any test hardware in existance that could be
used?
And besides: they talk about putting this comsat on a fast trajectory to Jup.
Why would they be able to do that, when they were not able to when G was
launched? Can they really make a comsat sufficiently lighter that existing
boosters can put it on a faster track?
Burns
|
| 560.333 | | 25415::MAIEWSKI | | Fri May 03 1991 16:12 | 8 |
| How about using a TDRS? It's designed to pick up signals from a moving
target and broadcast them back toward Earth.
Of course, it is kind of heavy. Also, what ever they send will have to
have nuclear energy source. Plenty of technical and political problems
there.
George
|
| 560.334 | | DECWIN::FISHER | "I am NOT a Merry Man"--Worf | Fri May 03 1991 16:30 | 19 |
| TDRSS is an interesting idea. As you say, it was designed to pick up from a
satellite. However, beside the change from solar to RTG
power, there is still the issue of the Earth transmission it was designed for
would be a problem. I suspect it was designed to transmit to reasonable sized
antennae at relatively fixed locations on the ground. It might have trouble
with interplanetary distances and moving targets. It might be a place to start
though.
Hmmm. I wonder if it would have to be more radiation-hardened than the normal
earth-orbiting comsat.
Another thought: I wonder if there would be any significant difference in the
amount of orbit-insertion fuel required if it were orbited about one of J's
moons rather than J itself. Suppose the moon were on the far side of J. As
the spacecraft goes past J, J starts decelerating it. By the time it gets to
the orbit of the moon, J has done some of the work. Of course, the orbital
velocity around a moon will be lower than around J.
Burns
|
| 560.335 | | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Fri May 03 1991 16:48 | 6 |
| If you want to 'blue sky' about a Jovian Data Relay satellite, think in
terms of something the size of Ulysses. That's about the largest thing
that NASA can send on a direct transfer trajectory to Jupiter, using
Shuttle and an IUS/PAM-S stack.
gary
|
| 560.336 | Tough times for planetary probes are nothing new | ADVAX::KLAES | All the Universe, or nothing! | Fri May 03 1991 17:10 | 8 |
| I just hope people will remember when reading about all the recent
problems with GALILEO, MAGELLAN, ULYSSES, etc. that many earlier
planetary and lunar probes had serious, mission-threatening problems
during their journies, and most of them were able to complete their
tasks above and beyond the original plans.
Larry
|
| 560.337 | | DECWIN::FISHER | "I am NOT a Merry Man"--Worf | Fri May 03 1991 18:05 | 11 |
| No question about it, Larry. These are just "contingency plans". Unfortunately
there is not a redundant high-gain antenna aboard.
Hey! How about zapping the glue with a laser as G flings by the Earth!
Actually, another somewhat more practical thought would be that if they could
update the software to compress the data more tightly, they could fit more on
the tape recorder, and thus loose less even if they have to ship it back at
10 baud or whatever terrible rate that is!
Burns
|
| 560.338 | | 25415::MAIEWSKI | | Fri May 03 1991 19:40 | 5 |
| Here's one, how about doing Earth flybys that slow it down then use it's
engine to reenter earth orbit. Fix the antenna, refit a new engine, and
start the trip all over.
George
|
| 560.339 | | PRAGMA::GRIFFIN | Dave Griffin | Fri May 03 1991 22:16 | 10 |
| I've inquired about the status reports (or lack thereof). JPL's
status reports from the Galileo project office will continue to be irregular,
but they assured me they will continue to flow.
As for Galileo - it is in normal cruise mode and JPL is still deciding what
to do next. As many have noted, there is *plenty* of time to work on
this problem, and they have yet to do anything but a "nominal deploy attempt".
When they have something to say - we'll hear about it.
- dave
|
| 560.340 | | DECWIN::FISHER | "I am NOT a Merry Man"--Worf | Mon May 06 1991 15:26 | 4 |
| I fear that aerobraking from escape velocity to earth orbital speed would
not be good for a spacecraft not designed for it.
Burns
|
| 560.341 | GALILEO Update - May 3 | ADVAX::KLAES | All the Universe, or nothing! | Mon May 06 1991 19:02 | 39 |
| Article 30251
From: yee@trident.arc.nasa.gov (Peter E. Yee)
Newsgroups: sci.space
Subject: Galileo Status for 05/03/91 (Forwarded)
Date: 6 May 91 18:47:07 GMT
Sender: usenet@news.arc.nasa.gov (USENET Administration)
Organization: NASA Ames Research Center, Moffett Field, CA
GALILEO STATUS REPORT
May 3, 1991
The Galileo spacecraft early today entered safing mode,
flight controllers have reported.
In safing mode, the spacecraft dropped the speed of the
digital data it sends to Earth from 1,200 bits per second (bps) to 10
bps. In addition, the spacecraft carried out the first of a series of
Sun-pointing maneuvers designed to orient itself properly in relation
to the Sun as part of the safing response. In safing mode this
maneuver is automatically carried out every 12 hours.
According to the flight team, data from Galileo show that
the incident was caused when one of the spacecraft's two redundant
Command & Data Subsystem computers detected a problem with itself,
prompting it to take itself off-line. The other computer continued to
function properly and carried out all intended operations.
The incident appears similar to one March 26 when Galileo
also entered safing mode. In both cases the spacecraft reacted
exactly as intended. Flight controllers said the spacecraft is
responding properly to commands and they expected to have the rate of
data Galileo sends to Earth restored to 1,200 bps later today.
The incident is not expected to have any permanent effect on
the mission, and appears to be completely unrelated to the recent
difficulty in deploying Galileo's high-gain antenna. Engineers are
continuing to analyze antenna data and work with test equipment on the
ground.
|
| 560.342 | | 25415::MAIEWSKI | | Mon May 13 1991 19:30 | 5 |
| Who's talking about aerobraking?
With no heat shield, that would turn the entire probe into toast.
George
|
| 560.343 | | DECWIN::FISHER | "I am NOT a Merry Man"--Worf | Tue May 14 1991 16:34 | 5 |
| Yes, of course...that is what I was saying in my understated way. I thought
that is what you were suggesting a few notes before that, but rereading shows
me that you probably mean some sort of Earth gravity manuver.
Burns
|
| 560.344 | | 25415::MAIEWSKI | | Tue May 14 1991 19:45 | 8 |
| Yes, my thought was that they could use Earth flyby's reverse of what they
are doing now to slow it down and use the engine for Jupiter orbit insertion to
slow it down into earth orbit.
I thought about it some more, however, and this wouldn't work because the
engine is behind the Jupiter probe.
George
|
| 560.345 | Galileo Update On CNN | PRAGMA::GRIFFIN | Dave Griffin | Wed May 15 1991 16:27 | 35 |
| From: john@newave.UUCP (John A. Weeks III)
Newsgroups: sci.space
Subject: Galileo Update On CNN
Date: 2 May 91 02:36:43 GMT
Organization: NeWave Communications Ltd, Eden Prairie, MN
CNN ran an update of Galileo during Prime News tonight. They
showed several Jet Propeller Lab people working with a duplicate
of the high gain antenna. They think that the problem has to do
with the retainer mechanism that kept the antenna in its launch
mode position. They further think that the retainer is warped
from the heat of the Sun, which prevented one or more of the
antenna ribs from unfolding.
The Galileo high gain antenna is a series of ribs that unfold much
like an umbrella. There appears to be some type of wire mesh material
the fills in the area between the ribs making up the antenna dish.
The JPL person that was interviewed said that they have not tried
anything yet because they are not sure what went wrong. He said
that manuvering the space craft to put the antenna in the shade
might help. He concluded by saying that they will get serious about
building a repeater sattelite if they cannot fix Galileo in the next
6 months.
CNN ended the segment by saying that "informed space experts" estimate
that there is about a 1 in 10 chance of Galileo being fixed. But JPL
added that if there is a fix, they _will_ find it.
-john-
--
=============================================================================
John A. Weeks III (612) 942-6969 john@newave.mn.org
NeWave Communications ...uunet!tcnet!wd0gol!newave!john
|
| 560.346 | Galileo Status for 05/10/91 | PRAGMA::GRIFFIN | Dave Griffin | Wed May 15 1991 16:36 | 27 |
| From: yee@trident.arc.nasa.gov (Peter E. Yee)
Date: 10 May 91 21:39:37 GMT
Organization: NASA Ames Research Center, Moffett Field, CA
GALILEO MISSION STATUS
May 10, 1991
The Galileo spacecraft is about 46.5 million miles from Earth,
making its round-trip communication time 8 minutes 20 seconds. It
is just over 140 million miles, or 1.5 astronomical units from the
Sun. Speed in orbit is 55,600 mph.
The spacecraft is in a stable, quiescent cruise state,
transmitting at 1200 bits per second over the low-gain antenna.
The high-gain antenna is still partially deployed. Galileo is in
the all-spin mode, rotating at 2.89 rpm. The spin axis is being
maintained close to the Sun line by planned pointing maneuvers.
The only cruise-science instrument currently taking data is the
dust detector.
When the spacecraft entered its safing mode May 2, the command
and data subsystem functions were switched automatically from the
"A" computer string to the redundant "B" string because of a
spurious transient signal. Yesterday afternoon the Galileo flight
team commanded the "A" computer back on line, restoring fully
redundant operation.
|
| 560.347 | Galileo Status Report 5/15/91 | PRAGMA::GRIFFIN | Dave Griffin | Thu May 16 1991 19:03 | 22 |
| GALILEO MISSION STATUS
May 15, 1991
The Galileo spacecraft is 49.6 million miles from Earth,
making the round-trip communication time almost 9 minutes. Speed
in orbit is 54,526 mph; distance from the Sun is 143 million miles
or 1.54 astronomical units. The spacecraft has travelled 919
million of its 2.4-billion-mile looping course to Jupiter.
Galileo is in a stable cruise mode, spinning at about 2.9 rpm,
and transmitting engineering data at 1200 bits per second over the
low-gain antenna. Spacecraft health and performance are good
except that the high-gain antenna is only partly deployed.
This week the Galileo spacecraft team began a series of tests
to characterize this partly-open antenna. Yesterday the spacecraft
was shifted from all-spin to dual-spin (the aft section fixed in
inertial space) and back. Celestial and gyro data may reveal a very
slight wobble, verifying that the antenna opened off-center. It
will be a very subtle effect because the antenna is light and the
spacecraft heavy. Another test tomorrow, using radio signals, may
give more information on the antenna's shape.
|
| 560.348 | Galileo Status Report - 5/22/91 | PRAGMA::GRIFFIN | Dave Griffin | Fri May 24 1991 00:24 | 29 |
| GALILEO MISSION STATUS
May 22, 1991
The Galileo spaceccraft is almost 55 million miles from
Earth, receding at about 780,000 miles per day. Speed in orbit
is about 51,000 mph. Round-trip communication time is 9 minutes
46 seconds. Distance to the Sun is almost 147 million miles, or
1.58 astronomical units (Earth-Sun distance).
Beginning Monday and concluding today, Galileo's high-gain
antenna region has been warmed by the Sun; the spin axis was
shifted to about 45 degrees away from the Sun line. This
experiment was intended to see whether thermal expansion of the
antenna tower would relax restraining forces that might have kept
the antenna from deploying on April 11. Although the antenna
warmed significantly, it could only get a little warmer than it
had been in April. Galileo is moving away from the Sun, toward
the Asteroid Belt, and cooling as it goes; it will not be back
this close to the Sun until September 1992.
Telemetry did not indicate any obvious change in the antenna
rib positions during this warming experiment. Radio signal
measurements made Monday and this morning seem to show very
little change in signal pattern. These and other test data will
be thoroughly analyzed in the coming days.
In the meantime, all other aspects of spacecraft health and
mission performance are excellent. The flight team is working to
design Galileo's late-October encounter with the asteroid Gaspra.
|
| 560.349 | Galileo Status Report - 06/06/91 | PRAGMA::GRIFFIN | Dave Griffin | Sun Jun 09 1991 15:04 | 22 |
| GALILEO MISSION STATUS June 6, 1991
The Galileo spacecraft is 68 million miles from Earth, making
the round-trip communication time 12 minutes, 9 seconds. Speed in
orbit is down to 50,300 miles per hour, and the solar distance is
now 155 million miles.
This week the sun moved to such an angle that Galileo's sun-
gate sensor once again could see the shadow of one of the antenna
ribs sweeping by as the spacecraft rotates. This is how spacecraft
analysts originally estimated the position of the partially
deployed high-gain antenna; with indications from radio-signal and
other tests, this provides additional confirmation that the warming
maneuver conducted two weeks ago did not change the antenna's
position. A greater degree of warming will be available in about
15 months; in the meantime, Galileo will cool gradually as it
recedes from the Sun.
Otherwise, Galileo's health and performance are excellent. The
spacecraft is spinning at a little less than 3 revolutions per
minute and transmitting engineering telemetry data at 40 bits per
second.
|
| 560.350 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Tue Jun 18 1991 17:04 | 17 |
| AvWeek reports that the Galileo team now believes that the antenna deployment
is failing because of ???-ing while the spacecraft was being transported
on the ground.
Sorry, now I can't remember the exact verb they used, but the inference was
that something that was supposed to be smooth (the "umbrella shaft?) was
barked up. I've never heard the verb before, at least not used in this
context, which is why I remeber the meaning, but not the word.
Anyway, if true, it seems to me that this would be bad. It would be bad
because probably heating would not affect it much as it might have were the
problem glue.
Sigh.
Burns
|
| 560.351 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Tue Jun 18 1991 17:04 | 5 |
| I know...I think the word was "galling".
It certainly is galling that this would happen...
Burns
|
| 560.352 | | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Tue Jun 18 1991 17:42 | 6 |
| Yup, "galling". Maybe it derives from galls on plants, an abnormal
swelling on a branch or limb.
Or maybe they just made it up.
gary
|
| 560.353 | Now GALILEO wants FM Stereo! | JVERNE::KLAES | All the Universe, or nothing! | Tue Jun 18 1991 19:26 | 15 |
| Article 32307
From: wa2ise@cbnewsb.cb.att.com (robert.f.casey)
Newsgroups: rec.radio.shortwave,sci.space
Subject: Galileo probe hears AM radio stations
Date: 18 Jun 91 19:16:45 GMT
Sender: news@cbfsb.att.com
Organization: AT&T Bell Laboratories
In the June 8 Science News (vol 139, page 356), at the end of
article "Startling Tales from the Magnetotail" the last paragraph says
that Galileo's plasma wave detector detected AM radio station signals
when the probe was in Earth's magnetic tail. Guess this sets a record
for the longest DX of AM stations! The article doesn't say which band
it heard the stations, but here in USA, AM is usually means MW.
|
| 560.354 | Did it listen to "Raindrops Keep Falling on my Head"? | UNTADH::HAZEL | Million-to-one chances crop up nine times out of ten | Wed Jun 19 1991 07:48 | 7 |
| Re. .350:
Would the verb be 'furl'? That means the same as 'close' when referring
to an umbrella, or something which folds like one.
Dave Hazel
|
| 560.355 | AW&ST note on Galileo | LEVERS::HUGHES | TANSTAAFL | Wed Jun 19 1991 13:38 | 9 |
| From Aviation Week & Space Technology/June 17, 1991 p.39
Copied without permision.
Galileo Engineers believe that galling from the vibration of ground
transport is the most likely cause for the stuck high gain antenna on
the interplanetary spacecraft. Spacecraft controllers commanded the
umbrella-like high-gain antenna to open on Apr. 11, but telemetry
indicates it jammed after about 10% of actuator travel with a lopsided
deployment. (AW&ST Apr. 22, p.25)
|
| 560.356 | It's a word, all right | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Wed Jun 19 1991 15:28 | 4 |
| gall v. tr. To damage or break the surface of by or as if by friction or
abrasion; chafe; excoriate.
-American Heritage Dictionary
|
| 560.357 | | HELIX::MAIEWSKI | | Wed Jun 19 1991 16:26 | 8 |
| Considering how much problem they have unfurling things, you think they
would create the facilities to unfurl and furl these things at the Cape.
Anyway, any word on whether they will try to close it and open it again?
If it's a rough surface, maybe they could wear down the rough spot with
a few attempts.
George
|
| 560.358 | The Last Straw ..... | DC101::SCOLARO | Tardis Del., When it has to be there Yestdy. | Wed Jun 19 1991 17:35 | 18 |
| In all honesty, GALILEO is the straw that broke the cammel's back for me.
For years I have been a supporter of NASA. With Challenger, I was willing to
say, OK, there are some problems, but the organization is basically sound.
With HST, I was able to say "well that was all pre-Challenger, things are fixed
now.
But Galileo is different. This problem is a post-Challenger problem. In fact,
if I understand the problem correctly, this problem is because of the
trajectory change required by the lack of the Centaur. The new trajectory came
closer to the sun, requiring a slightly different design.
Get the Government as far out of the space business as possible. The last,
best task of the Government in this field should be to, in effect, "build a
highway", with lower launch costs.
Tony
|
| 560.359 | | PRAGMA::GRIFFIN | Dave Griffin | Wed Jun 19 1991 17:50 | 7 |
| I don't get it -- just who is going to plunk down billions of dollars
to take a close look at Jupiter? Monsanto? GM? CalTech? Harvard?
If Galileo really is beyond repair, and you've been a supporter of
NASA, why is this the last straw? I can check my history book, but
only about 60% of what NASA has ever attempted worked. This is a
price that the harsh environment we are wandering into exacts on us.
|
| 560.360 | Any number of those .... | DC101::SCOLARO | Tardis Del., When it has to be there Yestdy. | Wed Jun 19 1991 19:58 | 17 |
| Ok, I'll explain.
If you can get to space cheap, companies will explore. For many
reasons. Sell information for a profit, perform the operation for
public relations, etc. You get the idea. Perhaps even possibly
explore for mining reasons.
Yes, ok, maybe only 60% of what NASA does works. That is a VERY poor
risk. Galelio is what $1B? Wouldn't it be better to spend that money
on an inherently low cost space access technology, like NASP and then
be able to do things in space to reduce that 40% to 5%?
Maybe with cheap access to space, you could build the thingie in space,
so that you know it will work. Having to launch it from Earth implies
restrictions on dimesnions and the need to have deployable ites.
Tony
|
| 560.361 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Thu Jun 20 1991 15:27 | 26 |
| Sorry, I don't buy it:
> If you can get to space cheap, companies will explore.
I don't see many companies exploring the Antartic or the ocean bottom. That's a
lot cheaper and more likely to produce tangible short-term benefits than space
research.
> For many
> reasons. Sell information for a profit,
To whom? Scientific establishments funded by the government, I'd bet
> perform the operation for
> public relations, etc.
$A few million, maybe. Not $A few billion.
I don't say that NASA is perfect...far from it. I DO believe, though, that
the biggest problem we, both private and public sectors, have in research and
development is the fiscal year mentallity. No one can seem to make a long
term plan and stick to it. Moving to private industry won't help this.
Burns
|
| 560.362 | Time to cross over from the test pilot to the airline pilot phase | ZENDIA::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Thu Jun 20 1991 16:39 | 10 |
| Well Burns, I can see a few advantages to space over the Antarctic or
ocean floor. Natural resources not available anywhere else. Hard
vacuum, unlimited solar potential (solar furnaces) and weightlessness
all of which have benefits which can justify missions like Joust for 13
minutes of weightlessness. I haven't seen any industries requiring sea
water at 10s of atmospheres pressure or truely frigid conditions. (I
may not follow the right journels 8^)
Yep, I agree that they've got to justify sending up the next shipload
of consumables but we have the applications for that environment today.
|
| 560.363 | GALILEO Update - June 20 | JVERNE::KLAES | All the Universe, or nothing! | Mon Jun 24 1991 15:19 | 44 |
| Article 14562
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 06/20/91
Date: 23 Jun 91 22:00:52 GMT
Sender: nobody@jato.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Crossposted by Ron Baalke from the NASAMAIL P bulletin board
(All NASAMAIL board P items are O.K. for unlimited distribution per JPL PIO,
unless the postings indicate otherwise)
GALILEO MISSION STATUS
June 20, 1991
The Galileo spacecraft is almost 82 million miles from Earth,
receding at about 1 million miles each day. Its distance from the Sun
is 162 million miles. Speed in orbit is 48,347 mph; round-trip
communication time is nearly 15 minutes.
The spacecraft health and performance continue to be excellent,
except for the partly deployed high-gain antenna. Galileo's
engineering telemetry data rate has been reduced to 10 bits per second
(through the low-gain antenna) to permit communication with the
34-meter ground stations. The spacecraft is in the dual-spin mode,
with the upper part spinning at about 3.15 revolutions per minute and
the lower part not spinning.
Meanwhile back on Earth, the Galileo flight team has been very
busy designing and reviewing the next trajectory correction maneuver
planned for July 2, the next cruise sequence or computer program to
control spacecraft operations starting in September, and the Gaspra
asteroid encounter, scheduled for October 29. The team continues
intensive analysis and testing aimed ultimately at deploying the
high-gain antenna.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Imagination is more
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | important than knowledge"
|_____|/ |_|/ |_____|/ | Albert Einstein
|
| 560.364 | More on the antenna problem | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Tue Jun 25 1991 15:19 | 21 |
| Rats...I was going to bring and type in the latest on the antenna problem from
AvWeek, but I forgot. I'll paraphrase:
Essentially when the antenna is closed there are some cones on it that fit into
some inverse codes somewhere on the supporting structure. These were lubricated
pre-flight, but the lubrication was worn off when transporting the beast.
As G. flipped around close to the sun, heat/cool cycles caused galling on these
cones. During the first attempt to open the antenna, some of the ribs bent
a bit, causing the cones not to line up properly. They did not realize this
at first, so they thought that heat would move things in the right direction
to loosen it up. It didn't. Now they think that because of the bent ribs,
cooling is the ticket. They will try this at some point.
However, the Gaspra encounter will definitely be taped for later playback
rather than transmitted in real time even if the get the antenna open. This
is because of the time required to develop and validate the spacecraft command
sequences to do stuff. If they get the antenna open, there would not be enough
time to replan the encounter.
BUrns
|
| 560.365 | Latest on HGA Problems | VOSTOK::LEPAGE | Welcome to the Machine | Tue Jun 25 1991 18:59 | 38 |
|
Here is an excerpt from an article in the June 24 issue of AW&ST
on the problems with the Galileo high gain antenna. It appears they know
what's wrong and how to fix it:
"High friction caused by galling between standoff pins on the
antenna ribs and their conical receptacles on the antenna center structure
is the likely cause for the stuck 16-ft.-dia. antenna, according to
William J. O'Neil, Galileo project manager at the Jet Propulsion Laboratory.
Differential heat expansion between the graphite ribs and the aluminum/
beryllium center structure is believed to have locked some of the pins in the
receptacles as the center structure cooled and shrunk when Galileo traveled
away from the Sun.
"But as the antenna ribs were driven open, the stuck ribs bent,
rotating the pin forces from the top to the bottom of the receptacle, according
to the latest scenario. Previously engineers thought the center structure
should be warmed and expanded to free the ribs, and this was tried unsuccess-
fully in late May. Now they think the center structure should be contracted
because the main loads are believed to be on the bottom, instead of the top,
of the receptacles.
"Pointing Galileo's high gain antenna away from the Sun should provide
enough cooling, and this may be done this summer. Engineers are also studying
the natural frequency of the ribs and how they might be moved to jiggle them
free.
"A dry lubricant was applied to the 90-deg. Inconel receptacle cones,
but engineers believe that the vibration of ground transport made it rub away.
The hard vacuum of interplanetary space is conducive to galling since the
formation of protective oxides is prevented there."
This article also mentions that even if the high gain antenna is freed
before the October 29 encounter with Gaspra, the data will be stored and
transmitted later. The reason given is that it takes months to prepare and
test the complex spacecraft command sequences and there isn't enough time
to prepare a second set.
Drew
|
| 560.366 | Lubricant 'rubbed off'??!! | UNTADH::HAZEL | Million-to-one chances crop up nine times out of ten | Wed Jun 26 1991 06:17 | 18 |
| Re. the last two:
If the vibration of ground transport was able to make the dry lubricant
rub away, surely the vibration of launching the spacecraft would have
had a similar effect? In which case, does this mean that the wrong kind
of lubrication was used (ie. it did not suit the conditions which the
part had to endure)?
I thought lubrication of spacecraft parts was normally done by
impregnating the surface of moving components with something which
would make it naturally slippery? The process used for this is, I
believe, similar to case hardening, where heat is used to cause the
lubricant to diffuse into the surface. This would make it very unlikely
to be 'rubbed off', except by long-term wear of the kind the part was
designed to take.
Dave Hazel
|
| 560.367 | "surely"? Non sequitur. | PRAGMA::GRIFFIN | Dave Griffin | Wed Jun 26 1991 12:46 | 7 |
| While I don't disagree with the basic point you are trying to make, I
don't understand the logic in associating 8-12 minutes of vibration (launch)
with multiple hours of ground transportation vibrations.
If anything, the reverse statement would have been the one they forgot.
- dave
|
| 560.368 | Ground transport AND THEN launch | UNTADH::HAZEL | Million-to-one chances crop up nine times out of ten | Wed Jun 26 1991 14:58 | 8 |
| Re. .367:
But the launch vibrations happen _after_ ground transportation.
Therefore, if it doesn't handle terrestrial transport very well, it
won't be in any shape to survive launch either.
Dave Hazel
|
| 560.369 | !! | CLOSUS::J_BUTLER | L'audace, toujour l'audace! | Wed Jun 26 1991 15:43 | 17 |
| I, too, am rather surprised at ground-transportation-induced
troubles. I was with the Pershing missile system for quite awhile,
and later had some dealings with defense-related satellites/systems.
During ground movements, the containers transporting any of the
flight hardware were protected with rather sophisticated
shock-mountings! We even (accidentally) ROLLED a vehicle with
a guidance section in its container...and suffered NO shock
damage to the VERY sensitive guidance platform ("stable table"). That
ought to be more sensitive than an antenna...
I would hope a multi-million dollar spacecraft would get a better
container than a $36,000 guidance section, but....
John B.
|
| 560.370 | | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Thu Jun 27 1991 14:27 | 14 |
| The Pershing, as with other Army missiles, was designed to be carted
all over the place by road transport.
Galileo was not, and if I remember correctly it was trucked cross
country several times. It seems quite possible to me that something
designed to handle a few minutes of heavy vibration of known
characteristics might fail after hours of lighter vibration of unknown
characteristics.
Still, one would have hoped they'd have tested for this and the
expected heating effects from the VEEGA trajectory. One of the hazards
of changing the project at the last minute.
gary
|
| 560.371 | You're right: Army_msl.NES.NASA_spacecraft! | CLOSUS::J_BUTLER | L'audace, toujour l'audace! | Thu Jun 27 1991 14:44 | 12 |
| Re .370
You're right there! We sure did cart them all over the place!
It may well be that the container design considered just the
limited-transport functions and protected against "major"
shock.
Under those conditions, long-duration, low-intensity vibration
may well have been considered "negligible." If so, I hope the
lesson is learned...
John B.
|
| 560.372 | There was a NOVA episode on this puppy... | GUCCI::TSTOWERS | | Thu Jun 27 1991 16:02 | 25 |
| re .358
Actually GALILEO is a pre-Challenger problem child. There was a NOVA
episode called something like "Galileo, the rocky road to Jupiter" or
some such that was one a year or two ago. The flight plan has been
changed over and over again over the years (mostly due to the on-again
off-again Centaur-in-the-cargo-bay issues.) Its quite a distressing
story if you ever have a chance to see it.
re last few
I believe the same episode indicated it had been trucked from JPL to
the cape for launch but that got scrubbed for some reason. They
trucked it all the way back again and then back to the cape once again
for its final launch. A little more road work than they might have
planned.
Also, a note down in the 300's talking about Galileo launch delays
indicated that they had actully test deployed the High Gain at the cape
as part of the checkout. Could our lads have mucked it up then since
this is clearly after all the ground transport.
Finally... our only hope is that the folks at JPL can pull another
rabbit out as they have so often in the past...
|
| 560.373 | I have a story about that | UNTADI::HAZEL | Million-to-one chances crop up nine times out of ten | Fri Jun 28 1991 06:08 | 18 |
| Reply 372 reminded me of a something which happened to an acquaintance
of mine when we were doing an M.Sc. in Experimental Space Physics at
Leicester University, back in 1982.
He was writing a dissertation about Jupiter's moon Io. He decided to
add something about the Galileo probe, since this was sort of related
to the subject. While he was writing it, the discussion about how it
was to be injected into its transfer orbit was going on, and he kept
having to change his wording, according to what the latest information
was. The DAY AFTER he finally put his dissertation in to be bound, they
changed their minds again, so his dissertation had to be presented with
a factual error in it.
As it turned out, his dissertation was right after all, as he ended up
saying that Galileo would use the IUS.
Dave Hazel
|
| 560.374 | Galileo to set course for encounter with asteroid Gaspra | PRAGMA::GRIFFIN | Dave Griffin | Mon Jul 01 1991 14:09 | 31 |
| RELEASE: 91-99 (6/28/91)
NASA's Galileo spacecraft will turn and fire its small on-board
thrusters Tuesday, July 2, 1991, to set its course for an encounter
with the asteroid Gaspra in October 1991. Acting on computer
commands sent to it by engineers at the Jet Propulsion Laboratory
(JPL), the 2-1/2-ton spacecraft will begin its maneuver about 11
a.m. EDT.
The maneuver will alter Galileo's velocity in space by about 8
miles per hour, slowing it slightly and adjusting the flyby distance
at Gaspra on Oct. 29, 1991, to 1,000 miles.
The October event will be the first flyby of an asteroid.
Gaspra, about 8 miles across, orbits roughly 200 million miles from
the sun near the inner edge of the asteroid belt. Scientists
believe it is a fairly typical, small, rocky main-belt asteroid.
Galileo is enroute to Jupiter, where it will go into orbit in
December 1995 after sending a probe into Jupiter's atmosphere.
Following an October 1989 launch, the spacecraft flew by Venus and
the Earth in 1990 in gravity-assist passes to increase the
spacecraft's velocity. One more Earth gravity assist is planned in
December 1992 to pick up the last increment of velocity necessary to
reach Jupiter.
The Galileo mission is managed for NASA's Office of Space
Science and Applications by JPL.
- end -
|
| 560.375 | UPI Special Report: Galileo in trouble | PRAGMA::GRIFFIN | Dave Griffin | Tue Jul 02 1991 21:57 | 188 |
| From: clarinews@clarinet.com
Date: 27 Jun 91 17:23:15 GMT
adv weekend june 29-30 or thereafter
Engineers hopeful stuck antenna
Can be freed to save Galileo probe
By WILLIAM HARWOOD
UPI Science Writer
Tests indicate a jammed antenna crippling the $1.4 billion Galileo
Jupiter probe may pop free after a critical support structure contracts
in the cold of space, releasing stuck ribs keeping the umbrella-like
dish from fully opening.
If the theory is correct -- and engineers could learn the answer as
early as this summer -- Galileo will be restored to full operation,
removing a cloud that has shadowed the project since the gold-plated $3.
7 million ``high-gain'' antenna failed to open properly April 11.
``If all goes well, this whole thing might be behind us in two months
or so,'' said Galileo project manager William O'Neil.
But if the stuck ribs warping the 75-pound dish antenna refuse to
budge even after repeated attempts to coax them loose in the months
ahead, NASA would be faced with a potential space failure more
devastating than the well-publicized optical flaws hobbling the $1.5
billion Hubble Space Telescope.
Hubble, after all, is in Earth orbit where spacewalking shuttle
astronauts can install new instruments to counteract focusing problems
caused by the improper shape of the telescope's primary mirror.
But the nuclear-powered Galileo probe is well on the way to a 1995
encounter with Jupiter, hurtling through deep space at speeds and
distances far beyond the physical reach of shuttle repair crews.
While engineers believe they now understand what happened to the
antenna and what will be needed to get it open, some space agency
officials rate the odds of success at just 50-50.
``I agree that we've got a much better shot at it,'' said one
official who asked not to be named. ``But I still think we'll be lucky
if it opens.''
The stakes are painfully high.
Without the use of the 16-foot-wide high-gain antenna, Galileo's
smaller low-gain antenna would need some 12 days to transmit a single
image of Jupiter, two years to beam back a maximum of 60 or so pictures
compared to the thousands it was designed to take during the same
period.
While NASA could mount a crash effort to build and launch a satellite
to Jupiter to relay Galileo data back to the inner solar system, it is
unclear whether Congress would support a project that would add several
hundred million dollars to Galileo's already inflated price tag.
It also is far from clear whether such a complex satellite and the
nuclear generators required to power its systems could be built and
launched in time to assist Galileo, or whether NASA would be better
served by coming up with a different mission for the crippled Jupiter
probe.
Space agency officials hope such questions will never need an answer.
After months of tests and analysis, engineers at the Jet Propulsion
Laboratory in Pasadena, Calif., are cautiously optimistic the jammed
high-gain antenna will open properly after a maneuver now planned for
July or August.
Galileo, the most sophisticated -- and costly -- interplanetary
spacecraft ever built, currently is sailing away from the sun, on course
for an Oct. 29 asteroid flyby before looping back toward the inner solar
system next year for a final boost on toward distant Jupiter.
O'Neil said flight controllers are putting the finishing touches on
plans to re-orient the spacecraft so the antenna will be shaded from the
warmth of the sun, allowing the stuck hardware to chill down to minus
382 degrees Fahrenheit.
Engineers believe the three to five stuck ribs keeping the antenna
from opening fully may slip free once the dish's central column
contracts in the deep cold of space, releasing small pins holding the
ribs in place. After that, motors can be used to drive the antenna to
its fully open position.
``The calculations that we have suggest that in that configuration
the thermal stresses should be such that we get rib release,'' O'Neil
said. ``But we can't guarantee that in any way, we just have to try it.''
Space agency officials are concerned that if the initial attempt
fails it could have an adverse impact on sensitive budget negotiations
and plans to build advanced spacecraft to explore Saturn and an icy
comet.
``If the antenna opens when we do this maneuver, that'll be great,''
said an engineer. ``But if it doesn't open ... we'll be doing a lot of
different things as time goes on. There's a lot of time before we get to
Jupiter.''
Galileo, named after the Italian astronomer credited with discovering
Jupiter's four brightest moons, was built at the Jet Propulsion
Laboratory to study the solar system's largest planet during a planned
20-month orbital tour.
Equipped with a battery of high-tech cameras and other instruments,
Galileo will drop an instrumented probe into Jupiter's stormy atmosphere
before the mothership slips into orbit around the giant planet in
December 1995.
Sailing through a ballet of ever-changing orbits, Galileo's
electronic ears and eyes will study Jupiter's atmosphere, its whirling
moons and its space environment in exquisite detail, beaming back close-
up photographs 20 to 1,000 times better than the spectacular pictures
taken by the Voyager probes.
Whether that data returns to Earth in a trickle or a torrent depends
on the high-gain antenna.
Galileo was launched from the space shuttle Atlantis on Oct. 18,
1989, kicking off a six-year, three-planet celestial billiard shot
requiring the probe to sail once past Venus and twice past Earth for
velocity-boosting gravity-assist flybys required to fling the probe on
to distant Jupiter.
The spacecraft zoomed past Venus and Earth in 1990, gaining enough
speed during the second flyby to reach the asteroid belt between Mars
and Jupiter. On Oct. 29, Galileo will pass within 1,000 miles of an
asteroid named Gaspra for humanity's first close-up look at one of the
rocky bodies.
After falling back into the inner solar system, Galileo will sail
past Earth a final time on Dec. 8, 1992, reaching Jupiter in 1995 after
inspecting a second asteroid.
------
Two high-gain antennas were built by Harris Corp. of Melbourne, Fla.,
under a $7.4 million contract. Both were delivered to JPL in 1982 and
both are virtually identical to antennas that have been used without
incident by data relay satellites like one set for launch July 23 aboard
the shuttle Atlantis.
The Galileo antenna is made of gold-plated molybdenum mesh stretched
across 18 graphite-epoxy ribs connected by quartz wire. When the antenna
is closed, each rib is anchored to a central column by 18 spoke-like
pins.
To open the antenna, motors supplied by JPL turn a worm gear that
drives a nut upward, pushing the ribs away from the central column much
like an opening umbrella. In a normal deployment, the nut moves 3.4
inches, pushing levers that cause each rib to rotate outward 68 degrees.
The entire procedure takes about three minutes.
Because of Galileo's convoluted trajectory, the antenna had to be
kept closed until after the first Earth flyby to prevent the fragile
mesh from being damaged by heat from the sun. Finally, on April 11,
Galileo's on-board computer system executed stored commands to open the
antenna.
``We knew that we had a problem immediately because we saw high
currents into the motors,'' O'Neil said. ``They were working
considerably harder to drive the antenna out than they should have had
to.''
Telemetry from Galileo indicated the motors ``stalled out'' 56
seconds after starting. Based on the amount of torque the motors
generated, engineers ultimately were able to determine that the ball nut
moved only six-tenths of an inch instead of 3.4 inches as required for
full deployment.
A sensor mounted on the spacecraft was able to ``see'' one of the 18
ribs, which had moved outward 35 degrees from the stowed position. As
luck would have it, that rib was the one that had moved the farthest and
by simulating the same conditions on the backup antenna, troubleshooters
were able to determine the shape of Galileo's antenna.
``It all points to having between three and five adjacent ribs stuck
to the tower in some manner in their stowed position,'' O'Neil said.
``You've got an antenna that is on one side about half way out and on
the other side it's not out at all.''
Engineers believe the stuck ribs are being held in place by the pins
used to hold them to the central tower during launch. A dry lubricant
was applied before flight to ensure the ribs would easily pull free.
But Galileo's launch was repeatedly delayed because of shuttle
problems and in the wake of the 1986 Challenger accident, the probe had
to be shipped by truck from Florida to California and back again for
takeoff in 1989.
O'Neil said engineers now believe the long delays, coupled with the
vibration of two unexpected cross-country trips, caused the antenna to
lose critical lubrication.
``Our belief is that by the time Galileo got launched and was in the
hard vacuum of space, that lubricant was gone,'' he said.
While the antenna was successfully opened and closed in a routine
pre-launch test, the loss of lubrication and the extreme conditions of
the space environment apparently combined to cause the ribs to hang up
on April 11.
But JPL engineers, assisted by Harris Corp. personnel, recently
completed an exhaustive series of tests that show the antenna was not
damaged during the aborted opening procedure. The question, then, is how
to get the stuck ribs to open.
Galileo's on-board rockets are not powerful enough to jar the ribs
free and the motor used to drive the antenna open cannot be reversed to
allow a second deployment attempt.
But calculations show that if the central tower can be chilled enough
it will contract slightly and the frictional force on the pins holding
the stuck ribs in place will be released.
For that reason, Galileo will be oriented ``tail to the sun'' at some
point during the next two months so the tower will be fully shaded, a
procedure known as ``cold soaking'' the antenna.
If the antenna does not pop free, additional attempts will be made
when Galileo is even farther from the warmth of the sun, before the
spacecraft falls back into the inner solar system.
``If none of that works, the next thing we might try -- and I say
might -- is to vary it from hot to cold because as we come in we can get
it hotter than we can out at the asteroid belt,'' O'Neil said.
``If we don't have it out after going by Earth, say within a month or
two after (the second Earth flyby), we would pretty much have to say
there's not much prospect of ever getting it out.''
adv weekend june 29-30 or thereafter
|
| 560.376 | UPI: Galileo rescue mission debated | PRAGMA::GRIFFIN | Dave Griffin | Tue Jul 02 1991 21:59 | 74 |
| From: clarinews@clarinet.com (WILLIAM HARWOOD, UPI Science Writer)
Date: 27 Jun 91 17:23:17 GMT
UPI Special Report: Galileo in trouble
CAPE CANAVERAL, Fla. (UPI) -- If efforts to free a jammed antenna
crippling the $1.4 billion Galileo probe fail, the space agency might
consider a crash effort to build and launch a satellite to Jupiter to
relay pictures and other data back to Earth.
But a NASA official who asked not to be named said it would be
extremely difficult to mount such a mission in time to help Galileo,
scheduled to slip into orbit around Jupiter in 1995, especially given
ongoing debate over NASA's budget.
``I think it's unrealistic. No matter how you cut it, we're talking
about several hundred million dollars,'' he said. ``There's a launch
opportunity in January of '94, which gets there in '96. That's only a
couple of years from now and that's putting together a spacecraft pretty
damn fast.''
``So there are a lot of practical problems that suggests to me a '94
launch is probably not possible.''
He said such a satellite, which would require a powerful Air Force
Titan 4 rocket for launch, would have to be custom built and that it was
not clear whether NASA could obtain a set of nuclear generators to power
such a relay station in time for a quick mission.
But William Burrows, author of two detailed studies of America's
military and civilian space programs, said he believes Congress would
support construction and launch of a Galileo relay satellite, despite
the added cost.
``I think there's going to be a lot of resentment all the way around
if they can't get the antenna (open),'' Burrows said in a telephone
interview. ``But I also think, in terms of sending a relay spacecraft
out, that we've got the hook so deep in our mouths now there's virtually
nothing else to do.
``I mean, you can't scrub a mission like that given the amount of
money that's already gone into it. So I suspect that if they can find a
relatively inexpensive way to do it they're going to do it.''
The nuclear-powered Galileo probe was deployed from the shuttle
Atlantis Oct. 18, 1989, kicking off a six-year voyage to Jupiter.
An on-board computer attempted to open the spacecraft's primary
antenna on April 11, but telemetry indicated the $3.7 million umbrella-
like dish failed to fully deploy, putting the showcase mission in
jeopardy.
If the 16-foot-wide ``high-gain'' antenna cannot be fully opened,
pictures and other digital data would have to be relayed back to Earth
at a glacial 10 bits per second. And that translates into one picture
every 12 days or so compared to one per minute with an operational
primary antenna.
Engineers are cautiously optimistic they can coax the antenna open in
the months ahead, but one engineer rated the odds of success at just 50-
50.
Should those efforts fail, NASA would have few options. Project
manager William O'Neil said he believed a relay satellite could be
built, but it would not be as easy as some have speculated.
``It wouldn't take anything very complicated but it probably would
take something tailor made,'' he said. ``You couldn't just go and buy
some communications satellite.''
Rep. Jim Bacchus, D-Fla., whose district includes the Kennedy Space
Center in Florida, refused to speculate on whether Congress would
support a relay mission, saying ``I'll cross that orbit when I come to
it.''
``Based on what I know about the issue, I don't think it's going to
be necessary to send up any additional mission,'' he said. ``NASA seems
confident they can get the antenna open enough to fulfill it's mission
to Jupiter.''
adv weekend june 29-30 or thereafter
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|
| 560.377 | Galileo Update - 07/01/91 | PRAGMA::GRIFFIN | Dave Griffin | Tue Jul 02 1991 22:06 | 15 |
| From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Date: 2 Jul 91 01:29:55 GMT
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Project Manager for Galileo
GALILEO STATUS REPORT
July 1, 1991
The Galileo spacecraft is operating in the dual-spin mode and transmitting
coded telemetry data at 10 bps (bits/seconds). Today, the sequence memory load
for the TCM-10 (Trajectory Correction Maneuver 10) will be sent. Tomorrow,
TCM-10 is scheduled to be performed; the maneuver will impart a delta-velocity
of about 3.65 m/s using the lateral thrusters. The first pulse for the delta
velocity maneuver is planned to occur about 10:50 a.m. PDT.
|
| 560.378 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Wed Jul 03 1991 15:37 | 6 |
| I wonder if there is enough delta-v in the Jupiter-orbit-entry engines to
put G into a shuttle-accessible orbit around earth as it come by the second
time. Recovering and refurbing the spacecraft might be a better option than
trying to build a comsat in 2 years.
Burns
|
| 560.379 | | HELIX::MAIEWSKI | | Fri Jul 05 1991 17:44 | 14 |
| I thought of that and suggested it a few notes back but then I remembered
why it's a bad idea. If I understand correctly, the way it's stacked, the
Jupiter orbit insertion engine can't be used until the atmosphere probe is
released. The engine is pointing toward the probe:
+---------+--------+-------+
| Orbitor | Engine | Probe |
+---------+--------+-------+
^
+--- Separates here several months before
Jupiter Encounter
George
|
| 560.380 | So loose it... | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Sat Jul 06 1991 18:25 | 11 |
| So let it go!
(Clearly a determination has to be made of cost benefit...would the
cost of essentially wasting the probe, launch costs, and the cost of
tracking it for 2+ years minus plus the cost refurb and relaunch
(- the small amount of data you would get at 10 baud or whatever) be
worth the data one could get if it were launched again.
Ah well...I'm sure they have thought of it.
Burns
|
| 560.381 | | HELIX::MAIEWSKI | | Sun Jul 07 1991 22:38 | 16 |
| As I understand it, the probe should still work. The orbitor should be able
to receive data from the probe and store it on tape for playback at 10 baud.
That's probably the most important information in the program since the probe
will actually enter the atmosphere of Jupiter.
When ever I think or read about the atmosphere of Jupiter my mind boggles.
Think about it, it's the biggest non vacuum place in the solar system that
won't melt any metal that comes within a million miles. It may well be the
biggest non vacuum place within many light years. Because of it's size, Jupiter
may be very unique.
The potential for interesting science within Jupiter's atmosphere enormous.
If we don't get a single picture back, that probe may well make the entire
trip worth while.
George
|
| 560.382 | Galileo Status Report - 07/08/91 | PRAGMA::GRIFFIN | Dave Griffin | Tue Jul 09 1991 21:57 | 28 |
| Forwarded from William J O'Neil, Galileo Project Manager
Acronyms expanded by Ron Baalke
GALILEO STATUS REPORT
July 8, 1991
The Galileo spacecraft is operating in the dual-spin mode and
transmitting coded telemetry data at 40 bps. Today, commands were sent to
include AACS (Attitude and Articulation Control Subsystem) wobble related
information in the telemetry in support of the HGA (High Gain Antenna) anomaly
investigation effort.
Tomorrow, a mini-sequence will be sent to perform an RPM (Retro Propulsion
Module) maintenance activity and a DDS (Dust Detector) and SSI (Solid State
Imaging) instrument memory readout. Additionally, the memory load for the HGA
cooling turn activity will be sent; the cooling turn is planned for July 10.
At the start of track today, telemetry indicated the occurrence of the
twelfth CDS (Command Data Subsystme) CRC 2A POR (Power-On Reset) telemetry
indication. The telemetry signature was identical to that observed in all
previous occurrences; spacecraft operation is normal and unaffected by this
indication.
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
|
| 560.383 | Galileo Status 7/9/91 | PRAGMA::GRIFFIN | Dave Griffin | Wed Jul 10 1991 16:47 | 23 |
| GALILEO MISSION STATUS
July 9, 1991
The Galileo spacecraft is more than 106 million miles from
Earth today, making the round-trip communication time just over
19 minutes. It is almost 171 million miles from the Sun, and its
speed in orbit is 45,140 miles per hour. The spacecraft has
traveled more than 984 million miles since launch in October
1989, and has about 106 million miles to go before the Gaspra
encounter in October 1991.
Last week's trajectory correction maneuver, performed with
an accuracy of 0.4% (or about one part in 250), placed Galileo on
a path leading to a flyby 1000 miles from Gaspra on the afternoon
of October 29. Two more very small maneuvers may be used to
fine-tune the flyby, partly on the basis of star-field pictures
the spacecraft will take in the final weeks before encounter.
The spacecraft's health and performance continue to be
excellent, except for the partially deployed high-gain antenna.
Recent ground tests confirm the engineers' belief that 3 to 5 of
the 18 antenna ribs are stuck in the closed position. Tests and
analyses aimed at the eventual antenna deployment are continuing.
|
| 560.384 | | CLOSUS::J_BUTLER | L'audace, toujour l'audace! | Wed Jul 10 1991 17:30 | 9 |
| Can the antenna be retracted to the original (stowed) position
before closing? That might free, or reduce resistance on the
stuck hardware, or possibly allow any protrusions to "shrink"
from the cooling and allow re-opening.
Is there any indication of any warping of the antenna due to
the opening attempt?
John B.
|
| 560.385 | Choose option from a single element list - open | ZENDIA::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Wed Jul 10 1991 17:50 | 2 |
| It's been reported as a single (non-reversable) direction drive motor
8^(
|
| 560.386 | More HGA info | EMDS::SILVERSTEIN | Bob Silverstein | Tue Jul 16 1991 16:11 | 29 |
|
Hi,
During my eclipse cruise last week, I meet some people from JPL.
Needless to say, we talked about the HGA problem. I thought the
following would be interesting.
Originally the motor for the HGA could reverse. However, during the
many mission profile changes, the capability to reverse was removed
because they needed to control other things. Apparently I/O port space
is at a premium.
He also said that if the cooling maneuver now being tried does not work,
they will probably try driving the motors hard, even at the expense of
breaking a few ribs.
I also indicated that there are a lot of people here at DEC who follow the
space program, and they seemed pleased that others were interested. I
also said that our collective wishes for a successful mission go out the
the folks at JPL.
Bob
EMDS::Silverstein
DRACO::Silverstein
|
| 560.387 | Hope they sort things out the easy way | CHEST::HAZEL | Million-to-one chances crop up nine times out of ten | Wed Jul 17 1991 07:56 | 17 |
| If they drive the motor hard to open the antenna, what risks does this
involve, apart from the obvious one of breaking something on the
antenna?
If the antenna were to jam such that the motor couldn't move it any
further, could the motor sustain permanent damage? I suppose this
wouldn't matter much if its purpose was unachievable anyway.
Might there be any adverse effect on any electrical subsystems of
driving a motor harder than it was really intended to be driven? Also,
is there a chance of the antenna buckling, or becoming damaged in a way
which jeopardises other subsystems?
(I realise that the people at JPL will already be addressing these
questions, but I would be interested to know the answers).
Dave Hazel
|
| 560.388 | Galileo Status Reports - July 11, 12, 15 1991 | PRAGMA::GRIFFIN | Dave Griffin | Wed Jul 17 1991 22:04 | 61 |
| Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 11, 1991
The Galileo spacecraft is presently at the HGA (High Gain Antenna)
cooling attitude, in all-spin mode at 2.88 rpm, using the LGA-2 (Low Gain
Antenna #2) for communication. The spacecraft has completed 25 hours of the
planned 32 hour "cold- soak" period.
Commands were sent last night at about 2100 PDT to turn off the Bay E
replacement heater and the Accelerometer #1 supplemental heater to maintain
that hardware within flight allowable limits. Today, as of 0800 PDT, all
spacecraft temperatures are within flight allowable limits or limits
specifically waived for the turn.
HGA element temperatures achieved thus far are compatible with those used
in rib release calculations. Antenna temperatures are still dropping but
appear to be very near steady state levels.
At about 1630 PDT today the spacecraft " cold-soak" will be completed and
a planned sun acquisition will be performed. Subsequent to returning to sun
point, the spacecraft will be configured back to the pre-turn state.
GALILEO STATUS REPORT
July 12, 1991
The Galileo spacecraft completed its 32-hour "cold-soak" period and
returned to the sun pointed attitude, as planned, at about 1810 PDT on
July 11, 1991. Galileo is presently in the dual-spin mode at 3.15 rpm, using
LGA-1 (Low Gain Antenna #1) for communications. The telemetry data rate was
reduced from coded 40 bps to 10 bps consistent with planned DSN (Deep Space
Network) coverage. No spacecraft activities are planned for today, and no
tracking coverage is scheduled over the weekend.
GALILEO STATUS REPORT
July 15, 1991
The Galileo spacecraft is in the dual spin mode and transmitting coded
telemetry data 10 bps. Today, commands will be sent to:
o select 40 bps coded telemetry data rate consistent with
planned 70-meter tracking coverage
o perform a star scanner checkout activity to determine
if bright particles are present
o "permanently" open the star scanner shutter if no bright
particles are detected in the checkout activity
o perform a planned imaging instrument (SSI) engineering
status memory readout
Tomorrow, a mini-sequence will be sent to obtain AACS (Attitude and
Articulation Control Subsystem) wobble ID measurements which will be used in
conjunction with other data to determine if the HGA (High Gain Antenna) ribs
released.
|
| 560.389 | Galileo Mission Director Status Report (June 28 - July 11, 1991) | PRAGMA::GRIFFIN | Dave Griffin | Wed Jul 17 1991 22:05 | 263 |
| Forwarded from Neil Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
June 28 - July 11, 1991
SPACECRAFT
1. Commands were sent on June 28 to change the system fault
protection responses to ensure the thermal safety of the
SSI (Solid State Imaging) instrument in the event of a system
undervoltage condition or entry into spacecraft safing. The
flight software responses were changed in both CDS (Command
Data Subsystem) A and B prime and extended memories.
2. A command was sent on July 1 to configure the downlink
coded telemetry rate from 10 bps to 40 bps consistent
with link performance in preparation for the TCM-10
Trajectory Correction Maneuver #10) on July 2.
3. A mini-sequence of commands were sent on July 1 to power
on the EPD (Energetic Particles Detector) instrument and turn
off its replacement heater, perform a motor maintenance activity
and step the telescopes to the predicted minimum contamination
position (Sector 0) in preparation for the TCM-10
maneuver on July 2. After the maneuver on July 3, the
EPD was repositioned from Sector 0 to Sector 4.
4. Another command was sent on July 1 to power on the 8-watt
PCT (Photometric Calibration Target) heater to maintain proper
power balance into the RPM (Retro Propultion Module) tanks resulting
from the EPD instrument turn on and other spacecraft electrical
load switching.
5. The uplink sequence memory load for TCM-10 was sent on
July 1. The TCM-10 maneuver was designed to impart a
delta velocity of about 3.65 m/sec. The maneuver uses
the L-thrusters for four burn segments. TCM-10 is the
first Galileo turn-burn-turn maneuver and the first
targeted to the Gaspra flyby aim point.
6. The TCM-10 maneuver was performed as planned on July 10.
Prior to the start of the delta velocity burns, the
spacecraft was turned about 16 degrees from the sun line
to the maneuvered attitude using the P-thrusters.
Subsequent to the turn, a sequence attitude correction
of about 5 mrad was performed and proper maneuver
attitude was verified.
The spacecraft performance throughout the four-segment
burn maneuver activity was normal. AACS (Attitude and
Articulation Control Subsystem) and RPM performance was
near predicted levels; all RPM temperatures and pressures
were consistent with those observed during previous maneuver
activities. Sequence planned AACS spin rate corrections and
attitude corrections were performed after the second lateral burn
segment and the turn back to sun point. During the
second lateral burn the accumulated attitude error
reached about 10 mrad and was corrected to about 1 mrad;
no spin correction was needed. After the last burn
segment, the turn back to sun point was performed using
the P-thrusters. Following the turn to sun point, both a
spin correction and attitude correction were performed.
Preliminary analysis of navigation data indicates about
a 0.4 percent underburn was achieved.
7. Commands were sent on July 3 to perform a planned
imaging instrument (SSI) Memory Readout (MRO) to verify
its health and status via SSI engineering telemetry
data. Without an MRO, only SSI temperatures are
available.
8. Commands were sent on July 8 to include AACS wobble
information in telemetry in support of the planned HGA
(High Gain Antenna0 cooling turn on July 10. Without this
information in the telemetry, several MROs would be required
to collect this data.
9. A mini-sequence of commands was sent on July 9 to
perform the periodic RPM maintenance "flushing"
activity, a dust instrument (DDS) MRO and a planned SSI
MRO. Spacecraft performance during the "flushing"
activity was normal with thruster temperature profiles
similar to those observed during previous activities.
All 10-Newton thrusters were flushed except the P-thrusters
which are used routinely to perform attitude correction
updates.
The DDS and SSI MROs included DDS cruise science data
collected during the last six weeks and SSI engineering
housekeeping data to verify the SSI health and status.
10. At the start of DSS 63 (Deep Space Station 63, 70 meter
antenna) track on July 8, spacecraft telemetry indicated that
a CDS Critical Controller 2A POR (Power-On Reset) had occurred.
The telemetry signature observed was identical to the previous
eleven occurrences. Commands were sent on July 9 to reset the
telemetry indication; the telemetry indication was properly reset
thus verifying that the cause of the anomalous indication was
a transient spurious signal (see Special Topic 2).
11. The HGA cooling turn was performed on July 10. The
turn, which pointed the spacecraft's -Z axis about 165
degrees from the sun to shade the entire HGA, was
performed using the P-thrusters. Spacecraft performance
throughout the turn was normal; the turn angle achieved
was about 9 mrad from the expected 165 degrees. Having
reached attitude, the spacecraft was then commanded to
the all-spin mode for the duration of the nominally
planned 32-hour "cold-soak". "Quick look" review of
actual temperatures indicated that all were within the
design flight allowable temperature limits or
temperature limits waived specifically for the turn.
After about 12 hours at attitude, based on temperature
projections, action was taken to turn off the Bay E
replacement heater (12w) and the accelerometer
supplemental heater (0.9w) to remain within flight
allowable temperature limits. Subsequent to the heater
off commanding, temperatures began dropping and no
subsequent problems were observed. After 24 hours at
attitude, the HGA element temperatures reached very near
steady state values. The HGA final temperatures
achieved were compatible with those used in rib-release
analyses.
Two Delayed Action Commands (DACs) were sent on July 11,
prior to the end of the "cold-soak" period, to power on
the Bay E replacement heater and the accelerometer #1
supplemental heater which had been turned off to
maintain flight allowable temperatures. Both commands
were executed, as planned, after the spacecraft was back
to the sun-pointed attitude.
At about 1630 PDT, the spacecraft initiated the sequence
controlled sun acquisition maneuver using the P-
thrusters. Spacecraft performance throughout the
activity was normal and without incident. Several
minutes before the start of the sun acquisition, the PWS
(Plasma Wave) instrument was powered on via the sequence.
This was the first time the PWS has been powered since the
Earth 1 flyby in December 1990. After the sun acquisition and
still under sequence control, commands were executed to
return the spacecraft to the cruise pre-cooling turn
state except for the DDS instrument which was powered
off prior to the turn and PWS instrument which was
powered on during the turn sequence.
As expected, there was no real-time indication during or
after the cooling turn activity that the HGA ribs may
have released. The most reliable indicator of rib
release is spacecraft wobble angle information which
will be collected on July 16, 1991.
In addition to the wobble information, a 5-degree
spacecraft turn is scheduled for July 17, 1991, to
collect sungate data to determine if the antenna rib
positions have changed.
12. The AC/DC bus imbalance measurements exhibited some
variations. The AC measurement fluctuated about 2 DN
and was stable throughout the TCM-10 and the HGA cooling
turn activities; the measurement now reads 44.6 volts.
The DC measurement increased 12 DN and then dropped 12
DN prior to the start of the TCM-10 activity. The DC
measurement for the most part was fairly stable both
during the TCM-10 and HGA cooling activities although a
step increase and decrease of 19 DN over a short time
period (minutes) was observed near the end of the
cooling turn sun acquisition on July 11. The DC
measurement now reads 11.8 volts. All other power
telemetry and subsystem telemetry is normal.
13. The Spacecraft status as of end of day July 11 was as
follows:
a) System Power Margin - 79 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Spin Detector
d) Spacecraft Attitude Sun Point Angle - approximately
0.5 degree (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna - 10 bps
(coded)/LGA-1 (Low Gain Antenna)
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered off except PWS, HIC,
EPD, SSI & MAG
i) Probe/RRH - powered off, temperatures nominal
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 240 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. HGA cooling turn sequence was reviewed and approved on
July 8.
2. The EE2 (Earth-Earth 2) Prime Cruise Plan was reworked using
new Project Office suggested guidelines, reviewed and approved on
July 8. All open issues were resolved except for data
rate changes which may be commanded in the blind. This
issue will be worked during the Profile Design phase of
the uplink process.
GDS (Ground Data Systems):
1. The Project Change Board (PCB) and FPSO Change Board
approved plans for installation of the Space Flight
Operations Center (SFOC) Phase I in the Galileo Mission
Support Area (MSA). Phase I hardware installation is
scheduled to be completed in August. Phase II which
will include the remaining hardware is scheduled for
January 92.
TRAJECTORY
As of noon Thursday, July 11, 1991, the Galileo
Spacecraft status was as follows:
Distance from Earth 108,921,010 miles
Distance from Sun 171,582,150 miles (1.86 AU)
Heliocentric Speed 44,870 miles per hour
Distance from Gaspra 52,092,930 miles
Round Trip Light Time 19 minutes, 20 seconds
SPECIAL TOPICS
1. As of July 11, 1991, a total of 4970 real-time commands
have been transmitted to Galileo. Of these, 1901 have
been pre-planned in the sequence design and 3069 were
not. In the past two weeks, a total of 368 real time
commands were transmitted; 5 were pre-planned and 363
were unplanned. Major commanding activities included
TCM-10, the HGA cooling maneuver, resetting the CRC 2A
POR telemetry indication, SSI MROs, Command Loss Timer
resets, and various heater and RFS mode commands.
2. Sometime between the end of the DSS 14 (Goldstone 70 meter)
track on July 4 at 2250 PDT and the beginning of the DSS 63
(Madrid 70 meter) track at about 0900 PDT on July 8, a CDS
Critical Controller 2A POR indication occurred. The spacecraft
telemetry signature for this event was identical to the eleven
previous events. Spacecraft operation was completely
normal and unaffected by the events. This event was the
first in 1991; the last event occurred on December 31,
1990. The spacecraft has completed about 1.85 million
revolutions in the dual-spin mode as of July 4. The
anomalous POR telemetry indication likely was caused by
a transient spurious signal resulting from slip ring
brush debris in the spin bearing assembly.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Imagination is more
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | important than knowledge"
|_____|/ |_|/ |_____|/ | Albert Einstein
|
| 560.390 | Galileo Status Reports - July 16,17 1991 | PRAGMA::GRIFFIN | Dave Griffin | Wed Jul 17 1991 22:10 | 43 |
| Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 16, 1991
The Galileo spacecraft is operating in the dual spin mode and
transmitting coded telemetry data at 40 bps. Yesterday, the star scanner
checkout was completed with no evidence of bright particles detected; the star
scanner shutter was opened, as planned.
Today, an AACS (Attitude and Articulation Control Subsystem) wobble ID
activity will be performed. Wobble data collection will begin about 1330 PDT.
This data in conjunction with other data will be used to determine if the HGA
(High Gain Antenna) ribs released.
Tomorrow, Galileo is scheduled to perform a 5-degree turn off sun to
determine if the sun gate signal is being obscured by an antenna rib.
GALILEO STATUS REPORT
July 17, 1991
The Galileo spacecraft is operating in the dual spin mode and
transmitting coded telemetry data at 40 bps.
Yesterday, AACS (Attitude and Articulation Control Subsystem) wobble data
was collected, as planned. Data analysis is in process.
Today, a SITURN is scheduled to orient the spacecraft about 5 degrees off
sun point attitude to collect sun gate signal obscuration data. Sun gate data
will be collected for the next 5 days. This data, in addition to other data,
will be used to determine if antenna rib positions have changed. Also, power
turn on of the UVS (Ultraviolet Spectrometer) and DDS (Dust Detector) is
planned.
Tomorrow, no spacecraft activities are scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.391 | Well... | MAYDAY::ANDRADE | The sentinel (.)(.) | Thu Jul 18 1991 14:55 | 1 |
|
|
| 560.392 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Thu Jul 18 1991 15:32 | 5 |
| I wonder what kind of tests they give these guys during their hiring interviews
to see how patient they are. I would be SOOOOOO tempted to say, "Ok, they've
cooled down...crank up those motors!
Burns
|
| 560.393 | Well what? | PRAGMA::GRIFFIN | Dave Griffin | Thu Jul 18 1991 16:18 | 8 |
| As the report stated...
Data is being gathered until the 22nd - and then it will be analyzed....
- dave
[I, for one, have never understood the need for instant gratification -
especially for activities like this (which I have no personal stake in).]
|
| 560.394 | GALILEO Update - July 18 | JVERNE::KLAES | All the Universe, or nothing! | Thu Jul 18 1991 21:28 | 32 |
| Article 15261
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/18/91
Date: 18 Jul 91 21:58:49 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 18, 1991
The Galileo spacecraft is operating in the dual spin mode and
transmitting coded telemetry data at 40 bps.
Yesterday, the spacecraft completed the planned 2.5 degree turn
resulting in a 5-degree off sun attitude to determine if an antenna
rib is obscuring the sun gate signal. Quick-look data analysis
indicates rib obscuration is still present. This result is consistent
with the wobble data collected on July 16. It is concluded that no rib
release occurred. Another cooling turn is being planned in August.
Today, more sun gate data will be collected.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.395 | GALILEO Updates - July 18 | JVERNE::KLAES | All the Universe, or nothing! | Fri Jul 19 1991 14:22 | 245 |
| Article 15265
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 07/18/91
Date: 19 Jul 91 01:03:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from NASAMAIL P
GALILEO MISSION STATUS
July 18, 1991
The Galileo spacecraft is more than 118 million miles from
Earth today; round-trip communication time is 21 minutes. It is
approaching 174 million miles from the Sun, and the speed in
orbit is almost 44,000 miles per hour.
Spacecraft health and performance are excellent, with the
exception of the high-gain antenna, which is still partly deployed.
An experimental procedure commanded last week turned the antenna
away from the Sun, allowing it to cool down behind the spacecraft bus
shade for 32 hours. This reduced its temperature by about 100 degrees
Celsius ( 200 deg. F.), causing a temporary shrinkage as intended.
Tests performed and analyzed this week produced no evidence of the
release of the stuck antenna ribs. However, based on telemetry from
the cooling operation, the Galileo team concludes that greater cooling
would be worthwhile and can be achieved. Further experiments are
planned to achieve this.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
Article 15266
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo HGA Update - 07/18/91
Date: 19 Jul 91 02:10:50 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
GALILEO'S HGA STATUS REPORT
July 18, 1991
This was taken from my notes taken during the Galileo all-hands
meeting this morning. William O'Neil, the project manager for
Galileo, gave a one hour lecture on the current status of the High
Gain Antenna and the results of last week's cooling turn. Based on
the recent data from the AACS wobble and sungate sensor from the
spacecraft, it was concluded that there was no change in the HGA and
the ribs were not released. The most recent sungate sensor shows that
rib #2 is at 35.3 degrees, the same as it was prior to the cooling
turn. O'Neil is still confident, however, that the HGA will be
released in a second cooling turn. This second turn, scheduled for
mid-August, will cool the HGA tower at lower temperatures than the
first cooling turn. Additional equipment onboard the spacecraft will
also be turned off to help keep the temperatures down. A HGA tower
shrinkage of .1 inches through thermal contraction is expected to
spring the ribs loose.
Prior to the last week's cooling turn, it was suspected that four
of the 18 ribs (ribs 9 through 12) were stuck. With the recent data
received from the spacecraft, combined with the data from simulation
runs on the backup HGA here at JPL, it has now been determined that
only two ribs are stuck. When the ribs are released, they will be
released in sequential order with the last rib being the hardest to
release.
Galileo is now about 1.9 AU from the Sun and inside of the
astroid belt. Galileo was 1.32 AU from the Sun in April when the first
deployment was attempted. The spacecraft will reach aphelion in
January 1992 at which point it will be 2.3 AU from the Sun.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
Article 15270
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #3 - 07/18/91
Date: 19 Jul 91 02:59:44 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neil Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 12 - 18, 1991
SPACECRAFT
1. A NO-OP command was sent on July 15 to reset the command loss timer
to 240 hours, its planned value for this mission phase.
2. Following the return to sun-pointed attitude after the 32-hour HGA
"cold-soak" activity, telemetry indicated that the Probe shelf temperatures
were still increasing and, based on projections, could reach/exceed the
pre-turn agreed-to limits. Immediately prior to the start of the return to
sun point, probe shelf temperatures only had reached about 16 degree C.
Nearly 24 hours later, probe temperatures had gone above 21 degree C; pre-turn
agreed-to limits were 22.5 degree C (nominal) and 30 degree C (emergency). As
a consequence, unscheduled tracking coverage was procured (DSS-12) (Goldstone
34 meter station) to monitor the Probe temperatures for an additional nine
hours through midnight PDT on July 12, consistent with the Probe Engineering
Team tracking request. The T1 and T2 shelf temperatures remained stable
through the end of DSS 12 tracking coverage and no further coverage was
requested; both measurements were stable for a total of about 15 hours. On
Monday, July 15, Probe shelf temperatures had dropped to near 16 degrees C and
were continuing a downward trend.
3. Commands were sent on July 15 to perform a star scanner checkout, open the
star scanner shutter, and perform the periodic SSI (Solid State Imaging)
engineering status memory readout. The star scanner checkout activity known
as "peek-a-boo" was completed; no evidence of bright particles were observed
and the star scanner shutter was opened, as planned. The "peek-a-boo" activity
was performed as a precaution to protect the star scanner from "seeing" bright
particles which could have been released during the HGA cooling turn activity
if the ribs released.
4. A mini sequence was sent on July 16 to perform gyro-based wobble ID data
collection. These data in conjunction with other data are used to determine
if the HGA ribs released. Analysis of the data indicates no change in wobble
from the cooling turn.
5. A mini-sequence was sent on July 17 to perform a 2.5 degree turn to
determine if an antenna rib is obscuring the sun gate signal. The
sun-spacecraft-earth angle after the turn was about 5 degrees. Sun angle
drift will be used to collect sun gate data out to an angle of 6.5 degrees,
after which time a turn will be performed on July 22 to a 5-degree earth
leading attitude to provide 40 bps engineering telemetry. "Quick-look" data
analysis indicate that the sun gate was still obscured, confirming no rib
release.
The DDS (Dust Detector) and UVS (Ultraviolet Spectrometer) science instruments
were powered on July 17; the DDS was turned off for the cooling turn activity
and the UVS was turned off as part of the spacecraft safing response on May 2.
6. The AC/DC bus imbalance measurements exhibited some variations. The AC
measurement fluctuated 1 DN and now reads 44.6 volts. The DC measurement has
gradually increased from 11.8 volts to 13.3 volts. All other power telemetry
and subsystem telemetry are normal.
7. The Spacecraft status as of end of day July 18 was as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/star scanner
d) Spacecraft Attitude Sun Point Angle - approximately
5.0 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna - 40 bps
(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except NIMS, PPR,
PLS, and EUV
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 212 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
GDS (Ground Data Systems):
1. The Project Change Board (PCB) approved the FPSO Multimission Image
Processing Subsystem (MIPS) 5.2 delivery for Galileo support. The new
delivery which is part of the Galileo T.1 mission build configuration
provides a number of corrections and performance improvements needed for
Gaspra support. The new delivery is expected to be placed on line after
approval by the FPSO change board.
2. The SFOC (Space Flight Operations Center) Phase I hardware
installation was started with the installation of the first
workstation in the Galileo Mission Support Area (MSA). A total of 12
workstations will be installed in the MSA as part of the Phase I
installation scheduled for completion by mid-August. The Phase I
hardware will be used for "familiarization" and early testing prior to
the formal delivery of the Galileo software in SFOC versions 17 and 18
next year.
TRAJECTORY
As of noon (PDT) Thursday, July 18, 1991, the Galileo Spacecraft
status was as follows:
Distance from Earth 118,253,990 miles
Distance from Sun 174,565,540 miles (1.88 AU)
Heliocentric Speed 43,941 miles per hour
Distance from Gaspra 48,132,360 miles
Round Trip Light Time 21 minutes, 0 seconds
SPECIAL TOPICS
1. As of July 18, 1991, a total of 5094 real-time commands have been
transmitted to Galileo. Of these, 1903 have been pre-planned in the sequence
design and 3191 were not. In the past week, a total of 124 real time commands
were transmitted; 2 were pre-planned and 122 were unplanned. Major commanding
activities included resetting the command loss timer, selecting 40 bps data,
star scanner checkout and shutter open, wobble ID, SSI MRO, sun gate
obscuration turn and powering on the UVS and DDS instruments.
2. The fourth HGA anomaly special review board meeting was held at JPL on
July 16. The results of continued modeling and test efforts was presented.
Additionally, initial preliminary HGA motor turn on criteria was presented.
Recently modeling results suggests that prior to the cooling turn, there were
probably two ribs stuck to the tower and not the earlier postulated four ribs.
This conclusion is based on the close comparison achieved between flight data
and modeling data profiles for a 3 rib stuck to a 2 rib stuck case. Further
testing will be performed using the flight spare antenna to obtain motor
current and antenna shape information for a 3 rib, 2 rib and 1 rib stuck case.
The next special review board meeting is planned for August 22, 1991 at JPL.
3. A delta SSI cover deploy review was held at JPL on July 17. This review
was held to confirm the results of the February 1991 review and to identify
any differences in spacecraft state/performance or environment which could
affect cover deployment. Some significant differences were identified but are
not expected to affect cover deployment or its engineering verification.
Originally, the SSI cover deployment was planned for May 9 assuming 1200 bps
from the HGA; now 40 bps is available from LGA-1 (Low Gain Antenna #1); and
cover deployment now is planned for September 5, 1991. The clock position of
the scan platform may be changed from 0 degree to preclude the remote
possibility of the cover striking the LGA-2. This is a work item and is
expected to be resolved in the next two weeks.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.396 | GALILEO Update - July 19 | JVERNE::KLAES | All the Universe, or nothing! | Mon Jul 22 1991 21:01 | 28 |
| Article 15287
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/19/91
Date: 19 Jul 91 22:28:42 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 19, 1991
The Galileo spacecraft is operating in the dual spin mode and
transmitting coded telemetry data at 40 bps.
Today, no spacecraft activities are planned. Over the weekend,
previously planned tracking coverage to determine sun gate signal
obscuration is no longer needed; data collected earlier this week
indicates that the sun gate signal is still obscured by an antenna rib.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.397 | GALILEO Update - July 23 | JVERNE::KLAES | All the Universe, or nothing! | Wed Jul 24 1991 16:56 | 43 |
| Article 15360
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/23/91
Date: 24 Jul 91 05:37:32 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 23, 1991
At the start of the DSS-63 (Madrid 70 meter station) track on July 22,
the Ground Data System was unable to lock up to the 40 bps telemetry stream;
RF carrier lock was solid. After some analysis commands were sent to the CDS
(Command Data Subsystem) to change the source of downlink data stream from
LLM1A to LLM1B. Subsequently, the ground data system was able to achieve
telemetry lock. Telemetry indicated that the spacecraft had entered safing
and the CDS "A" string was down.
The spacecraft telemetry signature was identical to that observed on the
previous "A" string down. Telemetry indicated that the anomaly occurred about
1930 hours PDT on July 19. Commands were sent on July 22 to configure the
spacecraft to a thermally safe state and to perform an MRO (Memory Readout) to
verify the health and safety of the imaging instrument (SSI). Commands were
also sent to reset the CDS telemetry indicator, thus confirming that the "A"
string down was caused by a spurious transient bus "A" reset signal similar to
that on May 2.
The Galileo spacecraft is operating in the all-spin mode and transmitting
40 bps coded telemetry data from CDS LLM2B; the spacecraft is automatically
performing Sun acquisitions every 12 hours as commanded by the on-board fault
protection. Efforts to bring back the CDS "A" string and recover from safing
are in process.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.398 | GALILEO Update - July 24 | JVERNE::KLAES | All the Universe, or nothing! | Thu Jul 25 1991 12:52 | 27 |
| Article 15383
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/24/91
Date: 25 Jul 91 04:13:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 24, 1991
At the end of yesterday's DSS-63 (Madrid 70 meter station) tracking pass,
the Galileo spacecraft was in its safe all-spin mode and transmitting 40 bps
coded telemetry data. The spacecraft is being automatically commanded by the
on-board fault protection to perform sun acquisitions every 12 hours. Efforts
to bring the CDS A (Command Data Subsystem A) string back "on-line" are in
process. Today, no DSN (Deep Space Network) tracking pass is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.399 | GALILEO Update - July 25 | JVERNE::KLAES | All the Universe, or nothing! | Fri Jul 26 1991 15:10 | 74 |
| Article 15411
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/25/91
Date: 26 Jul 91 07:05:22 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 25, 1991
The Galileo spacecraft is in the safe all-spin mode and
transmitting 40 bps coded telemetry data. The spacecraft is being
automatically commanded by the on-board fault protection to perform
sun acquisitions every 12 hours. Since entering safing, the spacecraft
has performed 12 sun acquisitions.
Today, commands will be sent to recover and return the CDS
(Command Data Subsystem) "A" string back on-line. The total process
including command and verification time is expected to take nearly
eight hours. After completion, the CDS will be restored to fully
redundant operation.
Tomorrow, spacecraft recovery actions will continue.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
Article 15413
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 07/25/91
Date: 26 Jul 91 07:07:34 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from NASAMAIL P
GALILEO MISSION STATUS
July 25, 1991
The Galileo spacecraft is more than 126 million miles from Earth.
It is receding at almost 1.4 million miles per day, although the
spacecraft's speed in orbit is only 43,186 miles per hour.
Galileo's health and condition are stable and safe. The whole
spacecraft is spinning at a rate of 2.89 rpm, and the spin axis is
sun-pointed. It is transmitting telemetry at 40 bits per second over
the low-gain antenna; the high-gain antenna is still only partly
deployed.
On Friday, July 19, when the Deep Space Net was not tracking
Galileo, one of the spacecraft's redundant computers detected a
spurious transient signal. The spacecraft responded normally, taking
that computer off line, putting itself in the all-spin mode and
initiating automatic sun-pointing every twelve hours. This response is
called fault protection or safing. The Galileo team expects to bring
the computer back on-line and out of the automatic safe mode in a few
days.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.400 | GALILEO Updates - July 19-25 | JVERNE::KLAES | All the Universe, or nothing! | Fri Jul 26 1991 18:31 | 160 |
| Article 15450
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/26/91
Date: 27 Jul 91 01:28:32 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neil Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 19 - 25, 1991
SPACECRAFT
1. At the beginning of the DSS-63 (Madrid 70 meter station) track on July 22,
the DSN (Deep Space Network) was unable to lock up to the 40 bps coded
telemetry stream; RF carrier lock was solid (at the end of the DSN track on
July 19, the spacecraft was operating normally). After some analysis, commands
were sent to change the source of the downlink data stream from Low Level
Module (LLM) 1A to LLM1B. Subsequently, telemetry lock was achieved and the
data indicated the spacecraft had entered safing and the CDS (Command Data
Subsystem) "A" string was down; the telemetry signature was identical to that
observed for the previous "A" string down anomaly. Based on the sun
acquisition sequence profile, it was estimated that the anomaly occurred about
1930 PDT on July 19; the scheduled July 19 DSN track ended about 1230 PDT.
After further analysis, commands were sent to configure the spacecraft to a
thermally safe state (turned off RCT-NIMS (Near Infrared Mapping Spectrometer)
heater and turned on PCT (Photometric Calibration Target) heater No. 2) and the
SSI (Solid State Imaging camera) was swapped to the CDS "B" string to perform a
memory readout to verify the health and safety of the imaging instrument.
Commands were also sent to reset the CDS telemetry indicator, thus confirming
the expectations that the "A" string down was caused by a spurious transient
bus "A" reset signal similar to that observed on May 2.
2. Commands were sent on July 22 to perform a diagnostic memory readout of
selected locations on the "B" string to verify their contents; no unexpected
indications were observed. Later on July 25, commands were sent to
reconfigure the CDS "A" string for recovery and restart. These commands were
nearly identical to those used to recover and restart the previous CDS "A"
string in May 1991. Some minor changes were made to reduce vulnerability
periods to additional faults during the recovery process. All commands were
properly received and executed by the spacecraft and the CDS was brought back
"on-line" and fully redundant CDS operation was restored. Near the end of the
recovery and restart activity, the CDS "A" string was selected as the prime
string as it was prior to the anomaly.
Commands were sent on July 26 to halt the 12-hour fault protection commanded
automatic sun acquisitions, reacquire celestial reference, power on the HIC
(Heavy Ion Counter), and "swap" the SSI to the CDS "A" string. A total of 12
automatic sun acquisitions were commanded since entering safing on July 19.
3. The AC/DC bus imbalance measurements exhibited some change. Because the
CDS "A" string was down, no AC bus imbalance measurement was available for most
of the week. However, when the CDS "A" string was put back "on-line", the AC
measurement read 45.2 volts, 2 DN higher than last week. The DC measurement,
available from CDS "B" string, has gradually increased from 13.3 volts to about
14.6 volts. All other power telemetry and subsystem telemetry are normal.
4. The Spacecraft status as of end of day July 25 was as follows:
a) System Power Margin - 76 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/star scanner
d) Spacecraft Attitude Sun Point Angle - approximately
0.6 degree (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna - 40 bps
(coded)/LGA-1 (Low Gain Antenna #1)
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered off except EPD, DDS,
SSI, and HIC
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 240 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. Generated and tested the CDS "A" string recovery files.
2. Generated the celestial reference files.
GDS (Ground Data Systems):
1. A repeat test of the GSOC-JPL (GSOC = German Space Operations Center) High
Speed Data Line Anomaly Replay test was conducted July 23. GSOC utilized its
new External Data Interface (EDI) software. The test was successful in meeting
its primary objective, to validate that GSOC can transmit the correct Earth
received time in the telemetry GCF (Ground Communications Facility) header.
This was done successfully for 7.68 kbps LRS data. However, GSOC was never
able to output 1.2 kbps EHR data; the cause of the problem was not immediately
determined. A 1.2 kbps data test may be scheduled later.
2. The GSOC Ground Data System Readiness Review was conducted July 22-24 at
GSOC. The purpose of this review was to assess Ground Data System readiness
for cruise operations.
TRAJECTORY
As of noon Thursday, July 25, 1991, the Galileo
Spacecraft status was as follows:
Distance from Earth 127,807,780 miles
Distance from Sun 177,429,940 miles (1.90 AU)
Heliocentric Speed 43,060 miles per hour
Distance from Gaspra 44,319,110 miles
Round Trip Light Time 22 minutes, 42 seconds
SPECIAL TOPICS
1. As of July 25, 1991, a total of 5477 real-time commands have been
transmitted to Galileo. Of these, 1903 have been pre-planned in the sequence
design and 3574 were not. In the past week, a total of 383 real time commands
were transmitted; all were unplanned. Major commanding activities included
CDS "A" string down recovery activities, cancelling the automatic sun point
response, turning on the HIC and reacquiring celestial reference.
2. A second HGA (High Gain Antenna) cooling turn is being planned for August 12
at a solar distance of about 1.98 AU. This turn will incorporate several
changes to cool the antenna. Changes will include lowering the spacecraft bus
power consumption and increasing the dwell time at the cooling attitude.
Preliminary analysis suggests that electrical load power in the bus can be
reduced by about 70 watts, thereby causing somewhat lower antenna base
temperatures; PWS (Plasma Wave instrument) power reductions on the tower are
also being considered.
Recently HAC/AMES/JPL (HAC = Hughes Aircraft Company) have negotiated a not to
exceed probe temperature limit of 33 degrees C, including nearly 6 degrees C
for thermal "soak-back" observed in the last cooling turn; this new limit
represents a thermal constraint relaxation of about 11 degrees C. The highest
probe temperature of concern measured, at the cooling attitude, during the last
turn was 16.3 degrees C. Based on the relaxed thermal constraint, updated
probe model thermal predictions and accounting for modeling and other
uncertainties, the dwell time for next cooling turn will be nominally 50 hours,
compared with 32 hours for the last cooling turn.
3. As a consequence of the safing, several previously planned spacecraft
activities were cancelled including the Earth-lead SITURN, a wobble ID and
SCALPS activity, some routine RFS (Radio Frequency) engineering tests, a
telemetry low rate subcarrier RF link test and an RPM (Retro Propulsion
Module) 10-Newton maintenance activity; rescheduling of activities is in
process.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.401 | GALILEO Update - July 26 (#2) | MTWAIN::KLAES | All the Universe, or nothing! | Mon Jul 29 1991 12:50 | 31 |
| Article 15462
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 07/26/91
Date: 27 Jul 91 04:44:58 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 26, 1991
Yesterday, the CDS (Command Data Subsystem) "A" string was
brought back "on-line" and fully redundant CDS operation was restored.
Additionally, commands were sent to halt the fault protection
commanded automatic sun acquisitions, return to celestial reference,
powering on the HIC (Heavy Ion Counter) instrument and "swapping" the
imaging instrument (SSI) back to the CDS "A" string.
The Galileo spacecraft is operating in the all-spin mode and
transmitting telemetry at 40 bps. No DSN (Deep Space Network)
tracking coverage is scheduled for today, Saturday and Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.402 | GALILEO Update - July 29 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Jul 30 1991 11:09 | 24 |
| Article 15520
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/29/91
Date: 30 Jul 91 01:19:38 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 29, 1991
The Galileo spacecraft is operating in the all-spin mode and transmitting
coded telemetry data at 40 bps. Today, a command was sent to reset the command
loss timer to 240 hours, its planned value for this mission phase.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.403 | GALILEO Update - July 30 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Jul 30 1991 18:12 | 25 |
| Article 15554
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/30/91
Date: 30 Jul 91 22:59:19 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 30, 1991
The Galileo spacecraft is operating in the all-spin mode and transmitting
coded telemetry data at 40 bps. Tomorrow, the periodic RPM (Retro Propulsion
Module) 10-Newton thruster "flushing" maintenance activity and the periodic
imaging instrument (SSI) health status memory readout are planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.404 | GALILEO Update - July 31 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Jul 31 1991 20:17 | 31 |
| Article 15602
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 07/31/91
Date: 1 Aug 91 01:05:20 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 31, 1991
The Galileo spacecraft is operating in the dual-spin mode and
transmitting coded telemetry data at 40 bps. Early today, the
spacecraft completed an RPM (Retro Propulsion Module) 10-Newton
thruster "flushing" maintenance activity and an SSI (Solid State
Imaging) health status memory readout. After the 10-N thruster
"flushing" the spacecraft was commanded from all-spin to the dual-spin
mode. The spacecraft automatically entered the all-spin mode on July
19 as a result of safing caused by the CDS (Command Data Subsystem)
"A" bus reset anomaly. Tomorrow, Friday, and over the weekend, no DSN
(Deep Space Network) tracking coverage is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.405 | GALILEO Update - July 31 (#2) | MTWAIN::KLAES | All the Universe, or nothing! | Thu Aug 01 1991 13:48 | 44 |
| Article 15616
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 07/31/91
Date: 1 Aug 91 06:14:46 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from the JPL Public Information Office
GALILEO MISSION STATUS
July 31, 1991
The Galileo spacecraft is more than 136 million miles from Earth,
and still receding from Earth and Sun. It has travelled slightly more
than 1 billion miles since launch in its long looping trajectory; the
road runs another 81.7 million miles before the Gaspra encounter
October 29, and 1.347 billion miles before Jupiter orbit insertion in
December 1995.
Spacecraft health and mission performance are excellent, except
for the partly deployed high-gain antenna. Last Thursday the Galileo
flight team began commanding a return from last week's safe state to a
cruise state; the last stage in this process occurred on schedule
Tuesday night. Also Tuesday night the imaging instrument was checked
out and the propulsion subsystem was flushed, both regular routine
operations.
The team continues to be very busy developing the next
antenna-cooling experiment, based on continuing analysis of telemetry
from the first experiment and many ground laboratory tests. The next
experiment will probably take place in mid-August. The flight team
is also putting together the operational sequence controlling Gaspra
encounter preparations, which begin in September, as well as the
operation of the October 29 asteroid flyby itself.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.406 | GALILEO Updates - July 26 to August 1 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Aug 02 1991 18:20 | 105 |
| Article 15669
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/01/91
Date: 2 Aug 91 23:39:13 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neil Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 26 - August 1, 1991
SPACECRAFT
1. A NO-OP command was sent on July 29 to reset the command loss timer to 240
hours, its planned value for this mission phase.
2. A mini-sequence of commands was sent on July 31 to perform the periodically
required RPM (Retro Propulsion Module) 10-Newton thruster maintenance
"flushing" activity and an imaging instrument (SSI) memory readout to verify
its health and safety status; both activities were completed without anomaly
or incident. All twelve thrusters were flushed except the two P-thrusters
which are used for periodic sun pointing activities. Thruster temperature
profiles were similar to those observed during previous maintenance activities.
At the end of the mini-sequence, the spacecraft was commanded from the all-spin
mode to the dual-spin mode. The spacecraft entered the all-spin mode on
July 19 as a result of safing caused by the CDS (Command Data Subsystem) bus
"A" reset anomaly.
3. Commands were sent July 31, prior to the RPM maintenance activity, to
configure the radio subsystem to permit ranging data to be collected; Delayed
Action Commands (DACs) were also sent to configure radio subsystem back to its
previous sate. The DAC commands were executed, as planned, after the RPM
maintenance activity.
4. The AC/DC bus imbalance measurements exhibited some change. The AC bus
imbalance measurement changed 2 DN and now reads 45.6 volts. The DC
measurement increased 2 DN and now reads 14.9 volts. All other power
telemetry and subsystem telemetry are normal.
5. The Spacecraft status as of end of day August 1 was as follows:
a) System Power Margin - 67 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude Sun Point Angle - approximately
2.5 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna - 40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered off except EPD, DDS, SSI, and HIC
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 192 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. Project reviewed and approved command generation for the power
pre-conditioning sequence and the HGA (High Gain Antenna) cooling turn
sequence on July 31; the cooling turn is planned for August 12 and the power
pre-conditioning activity is planned to occur on August 5.
2. Project reviewed and approved the EE-2 (Earth-Earth 2) prime final profile
design on August 1. The EE-2 prime sequence is scheduled to be sent to the
spacecraft on August 29.
TRAJECTORY
As of noon (PDT) Thursday, August 1, 1991, the Galileo Spacecraft status was
as follows:
Distance from Earth 137,529,930 miles
Distance from Sun 180,175,080 miles (1.93 AU)
Heliocentric Speed 42,230 miles per hour
Distance from Gaspra 40,637,970 miles
Round Trip Light Time 24 minutes, 26 seconds
SPECIAL TOPICS
1. As of August 1, 1991, a total of 5482 real-time commands have been
transmitted to Galileo. Of these, 1904 have been pre-planned in the
sequence design and 3578 were not. In the past week, a total of 5
real time commands were transmitted; one was preplanned and four were
unplanned. Major commanding activities included resetting the command
loss timer, mini sequence to perform RPM flushing and SSI memory
readout activities, and commands to reconfigure the radio subsystem to
collect ranging data.
2. Beginning Monday, August 5, several spacecraft power electrical
load configuration changes are planned. These changes are part of the
preconditioning activity to support the HGA cooling turn on August 12.
The Bus/RPM power reduction (about 80 watts) is expected to lower the
average bus temperature by about 8 degrees C and consequently lower
the antenna tower temperatures.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.407 | GALILEO Update - August 2 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Aug 05 1991 21:30 | 25 |
| Article 15677
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/02/91
Date: 3 Aug 91 00:12:07 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 2, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry data at 40 bps. No DSN (Deep Space Network)
tracking coverage is scheduled over the weekend. Next DSN tracking pass is
early Monday, August 5, 1991.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.408 | GALILEO Update - August 5 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Aug 06 1991 19:23 | 35 |
| Article 15734
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/05/91
Date: 6 Aug 91 04:02:40 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 5, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry data at 10 bps.
Early today, a sequence of commands was sent to reconfigure the
spacecraft's electrical power state to cool the bus/RPM (Retro
Propulsion Module) in preparation for the HGA (High Gain Antenna)
cooling turn on August 12. The electrical power reconfiguration,
including an S-Band transmitter power reduction change, resulted in a
bus/RPM power reduction of about 80 watts.
Prior to the electrical power reconfiguration, engineering status
memory readouts were performed for the DDS (Dust Detector) and SSI
(Solid State Imaging) instruments; additionally the EPD (Energetic
Particles Detector) instrument completed a planned checkout.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.409 | GALILEO Update - August 6 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Aug 07 1991 20:36 | 28 |
| Article 15759
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/06/91
Date: 7 Aug 91 06:16:34 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 6, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry data at 10 bps. Galileo lost
the first 2 hours of its planned DSS-43 (Canberra 70 meter station)
5-hour tracking pass because the antenna had to be stowed to zenith
due to high winds in the area.
No spacecraft activities are planned for today and tomorrow.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.410 | GALILEO Update - August 7 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Aug 08 1991 20:35 | 42 |
| Article 15785
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/07/91
Date: 8 Aug 91 07:03:29 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from the JPL Public Information Office
GALILEO MISSION STATUS
August 7, 1991
The Galileo spacecraft is about 146 million miles from Earth, and
182.4 million miles from the Sun. Speed in orbit is 41,557 miles per
hour, and round-trip communication time is more than 26 minutes.
Spacecraft health and performance are excellent, except that the
high-gain antenna is still stuck in a partly-deployed position. The
spacecraft is in dual spin: the upper part is rotating at 3.15 rpm,
and the lower part is despun, held fixed relative to the stars.
Spacecraft engineering data are being transmitted over the low-gain
antenna at 10 bits per second.
The second experimental antenna cooling turn is scheduled for
next week, from Monday night to Thursday. Galileo will turn 165
degrees away from the Sun, as it did last month, to put the entire
high-gain antenna behind the large sun shield. This time the antenna
will stay in the shade longer, and, in addition, some electrical power
loads have been turned off and shifted away from the antenna. These
differences will permit the antenna to cool further than it did
before, making the central tower shrink a little more than it did
previously. As before, extensive post-cooling tests are planned.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.411 | GALILEO Update - August 8 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Aug 09 1991 15:00 | 26 |
| Article 15821
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/08/91
Date: 9 Aug 91 06:44:13 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 8, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry data at 10 bps. Today, no DSN
(Deep Space Network) tracking pass is scheduled. Tomorrow, the HGA
(High Gain Antenna) cooling turn sequence is scheduled for
transmission to the spacecraft.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.412 | GALILEO Updates - August 2-9 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Aug 09 1991 18:10 | 138 |
| Article 15848
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 08/08/91
Date: 10 Aug 91 00:41:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neil Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 2 - 8, 1991
SPACECRAFT
1. Early Monday, August 5, a sequence of commands was sent to reconfigure the
spacecraft's electrical power state to cool the bus/RPM (Retro Propulsion
Module) in preparation for the HGA (High Gain Antenna) cooling turn on
August 12. The electrical power reconfiguration consisted of turning off
selected loads, reducing the S-Band transmitter power level (high to lower
power), and reducing system power margin by "shifting" the excess power from
the RPM shunt heater on the spun side to the external shunt heaters on the
despun side; the bus/RPM power reduction was about 80 watts.
2. Prior to the electrical power reconfiguration on August 5, engineering
status memory readouts were performed for the DDS (Dust Detector) and SSI
(Solid State Imaging) instruments; additionally the EPD (Energetic Particles
Detector) instrument completed an engineering checkout.
3. Both the spacecraft bus and RPM tank temperatures are dropping in response
to the power reconfiguration on August 5. Temperature reductions for the RPM
tanks are near predicted levels but the bus temperatures are dropping somewhat
more slowly than predicted.
4. The AC/DC bus imbalance measurements exhibited some change. The AC bus
imbalance measurement dropped 2 DN and now reads 45.03 volts. The DC
measurement has gradually increased and now reads 17.7 volts. All other
power telemetry and subsystem telemetry are normal.
5. The Spacecraft status as of end of day August 8 was as follows:
a) System Power Margin - 42 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude Sun Point Angle - approximately
4.7 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna - 10 bps
(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered off except EPD, and SSI
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 168 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. Project reviewed and approved command transmission for the HGA cooling
turn sequence on August 8; the cooling turn is planned for August 12 with
sequence uplink transmission planned for August 9.
2. Project reviewed and approved the EE-3 (Earth-Earth 3) prime cruise plan
sequence design on August 6; the EE-3 prime sequence contains the Gaspra
encounter activity.
TRAJECTORY
As of noon Thursday, August 8, 1991, the Galileo Spacecraft status was as
follows:
Distance from Earth 147,374,770 miles
Distance from Sun 182,800,840 miles (1.96 AU)
Heliocentric Speed 41,450 miles per hour
Distance from Gaspra 37,074,480 miles
Round Trip Light Time 26 minutes, 12 seconds
SPECIAL TOPICS
1. As of August 8, 1991, a total of 5493 real-time commands have been
transmitted to Galileo. Of these, 1904 have been pre-planned in the sequence
design and 3589 were not. In the past week, a total of 11 real time commands
were transmitted; all were unplanned. Major commanding activities included
power reconfiguration in support of the cooling turn, switching the S-Band
transmitter from high to low power, selecting 10 bps telemetry data rate and
performing memory readouts for the DDS, EPD, and SSI instruments.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
Article 15849
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/09/91
Date: 10 Aug 91 00:43:06 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 9, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry data at 10 bps.
Early today, several command activities were completed. In addition to
uplinking the cooling turn sequence, commanding activity included sending:
a) Delayed Action Command (DACs) to turn off/on two heaters;
the heaters will be turned off tomorrow and turned back on 34
hours later,
b) DACs to turn on the PWS (Plasma Wave) instrument on August 15
after the sun acquisition,
c) Commands to disable the PWS magnetic field temperature monitor
and turning off the magnetic field 3-watt heater,
d) Commands to change and reset the command loss timer to 7 days.
Spacecraft activities over the weekend are limited to turning off the two
heaters via DACs.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.413 | GALILEO Update - August 12 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Aug 12 1991 19:38 | 31 |
| Article 15910
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/12/91
Date: 13 Aug 91 00:28:30 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 12, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and is transmitting coded telemetry data at 10 bps.
The two delayed action commands to turn off heaters sent last
Friday were executed by the spacecraft, as planned, on Saturday.
Today, about 1930 PDT, the spacecraft will initiate a 165 degree
turn (tail-to-the-sun) to cool the HGA (High Gain Antenna) tower. The
spacecraft is expected to remain at the cooling attitude for a planned
50 hours.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | "Computers are useless.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | They can only give you
|_____|/ |_|/ |_____|/ | answers." Pablo Picasso
|
| 560.414 | | FASDER::ASCOLARO | Tardis Del., When it has to be there Yestdy. | Mon Aug 12 1991 19:53 | 4 |
| So we know on Thursday or Friday if the mission is a success or a
failure?
Tony
|
| 560.415 | GALILEO Update - August 13 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Aug 14 1991 19:12 | 33 |
| Article 15949
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/13/91
Date: 14 Aug 91 02:12:18 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 13, 1991
The Galileo spacecraft is at the HGA (High Gain Antenna) cooling
attitude, operating in the all-spin mode and transmitting coded telemetry
at 10 bps; the spacecraft achieved the cooling attitude at about 2200
hours, PDT. The tower temperatures, after 7 hours at attitude, as
expected, are cooler than those observed during the first turn.
Temperatures along the HGA tower are continuing to drop. Today,
as of 0515 PDT, the PWS (Plasma Wave) magnetic field preamp temperature
reached zero DN (approx -95 degrees C), the S-band Feed Horn temperature
was -105 degrees C and the HGA motor temperature was -47 degrees C.
Galileo is planned to remain at the cooling attitude for 50 hours.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.416 | GALILEO Update - August 14 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Aug 15 1991 14:07 | 82 |
| Article 15989
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/14/91
Date: 15 Aug 91 04:35:05 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 14, 1991
The Galileo spacecraft is at the cooling attitude, operating in
the all-spin mode and transmitting coded telemetry at 10 bps. As of
0800 PDT, the spacecraft has been at the cooling attitude about 34 hours.
Temperatures along the HGA (High Gain Antenna) tower are
continuing to drop. As of 0500 PDT, the S-Band Feed Horn temperature
was -137 degrees C, the HGA motor temperature was -59 degrees C and
the LGA-1 (Low Gain Antenna #1). Body temperature was -174 degrees C.
All Orbiter and Probe temperatures are currently within acceptable limits.
Galileo is planned to remain at the cooling attitude until
midnight tonight.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
Article 15990
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 08/14/91
Date: 15 Aug 91 06:37:05 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from the JPL Public Information Office
GALILEO MISSION STATUS
August 14, 1991
The Galileo spacecraft is about 156 million miles from Earth,
making the round-trip communication time 28 minutes. It is 185
million miles, or almost twice as far as Earth is, from the Sun.
Speed in orbit is currently 40,800 miles per hour.
The spacecraft is in the all-spin mode, rotating at some 2.86 rpm
with its high-gain antenna turned 165 degrees away from the Sun so
that it is in shadow. This is the second antenna cooling experiment,
which began last week when a number of heaters and other electrical
devices were switched off and continued Monday evening, August 12,
when the spacecraft turned to this anti-solar orientation. Already
Galileo's upper parts, near and including the partly deployed
high-gain antenna, are colder than was achieved during the first
cooling experiment last month. It remains to be seen whether this
experiment, which continues till the early hours of tomorrow
(Thursday) morning, will cool and cause shrinkage sufficient to free
the antenna ribs which are believed to be stuck in the closed position.
There is no direct way to measure the shrinkage or to observe the
freeing of stuck ribs. What Galileo's flight team must do, after the
spacecraft returns to the normal cruise mode, is to collect gyro data
for an extended period, to measure the degree and direction of wobble
as the spacecraft rotates. From the wobble measurements they can
infer the offset in Galileo's center of gravity due to the canted,
partly deployed antenna--or the lack of this offset if the stuck ribs
have been freed. It may take a few days to collect, process, and
analyze the data.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.417 | GALILEO Update - August 15 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Aug 16 1991 18:36 | 31 |
| Article 16015
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/15/91
Date: 15 Aug 91 21:11:20 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 15, 1991
The Galileo spacecraft completed the 50-hour "cold-soak" HGA
(High Gain Antenna) cooling turn activity. The spacecraft was
automatically commanded via the on-board stored sequence to return to
Sun pointed attitude; Sun point was achieved about 0130 PDT.
The spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry data at 40 bps.
Tomorrow, a star scanner checkout activity is scheduled prior to
the planned "permanent" opening of the star scanner cover.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.418 | Will the antenna fully open? | MTWAIN::KLAES | All the Universe, or nothing! | Fri Aug 16 1991 18:36 | 90 |
| Article 1615
From: clarinews@clarinet.com (WILLIAM HARWOOD, UPI Science Writer)
Newsgroups: clari.tw.space
Subject: Galileo antenna problems studied
Date: 15 Aug 91 19:10:24 GMT
Engineers pored over telemetry from NASA's $1.4 billion
Galileo Jupiter probe Thursday, looking for evidence that the deep
cold of space had caused enough contraction to free a jammed radio
antenna crippling the costly spacecraft.
Acting on commands radioed up last week, Galileo reoriented
itself Monday so that its partially-open umbrella-like dish antenna
would be shadowed from the warmth of the sun, allowing a central
support column to chill down as much as possible.
Analysis indicates that if the column can be chilled
sufficiently, it will contract enough to release small pins holding at
least two of 18 antenna ribs to the support tower.
If the theory is correct, the stuck ribs will pop free,
restoring Galileo to full operation and removing a cloud that has
shadowed the project since the gold-plated $3.7 million ``high-gain''
antenna failed to open properly April 11.
``It'll be early next week before we'll be able to say
anything definitive because there's quite a bit of data we have to now
take in the normal attitude with the guidance and control system,''
said project manager William O'Neil at NASA's Jet Propulsion
Laboratory in Pasadena, Calif.
The first such ``chill out'' was conducted last month, but the
antenna refused to budge. This time around, engineers subjected the
central column to the deep cold of space for a longer period -- 50
hours -- and turned off spacecraft heaters to chill it even more.
Galileo returned to normal cruise attitude early Thursday.
Because part of the spacecraft spins, the partially open antenna
causes a minute wobble detectable in telemetry monitored on Earth. If
the antenna popped free, its shape would be more symmetrical and the
wobble would decrease accordingly.
Project officials at JPL began recording data Thursday,
looking for a hint of success. But it will take several days to come
up with a definitive conclusion.
Galileo, the most sophisticated -- and costly --
interplanetary spacecraft ever built, was launched from the shuttle
Atlantis Oct. 18, 1989. It currently is sailing away from the sun, on
course for an Oct. 29 asteroid flyby before looping back toward Earth
for a velocity- boosting flyby next year that will fling the probe on
toward Jupiter.
If all goes well, Galileo will slip into orbit around the
giant planet in July 1995, dropping a probe into Jupiter's atmosphere
before beginning a two-year study of the solar systems's largest
planet and its many moons.
But the high-gain antenna is crucial to Galileo's success.
Without it, Galileo's smaller low-gain antenna would need some 12 days
to transmit a single image of Jupiter, two years to beam back a
maximum of 60 or so pictures compared to the thousands it was designed
to take during the same period.
The antenna, which opens much like an umbrella, failed to
fully deploy April 11. Since then, engineers have been struggling to
figure out what went wrong and what can be done to fix it.
Analysis of telemetry from the spacecraft convinced engineers
that at least two of the antenna's 18 ribs remained stuck to the
central support column while the rest were free. Further analysis
showed the stuck ribs would pop free if the central column could be
sufficiently cooled.
``If we can get the thing cold enough, it ought to work,''
O'Neil said. ``The question is, how do we get it cold enough and have
we gotten it cold enough yet? I'm hoping it'll all be academic by Monday.''
If the effort fails, other attempts will be made later as
Galileo sails even farther from the sun.
But if the stuck ribs warping the 75-pound dish antenna refuse
to budge even after repeated attempts to coax them loose in the months
ahead, NASA would be faced with a potential space failure more
devastating than the well-publicized optical flaws hobbling the $1.5
billion Hubble Space Telescope.
Engineers remain optimistic, however, that the antenna will
open eventually, permitting Galileo to complete its mission.
|
| 560.419 | GALILEO Updates - August 9-16 | MTWAIN::KLAES | All the Universe, or nothing! | Sun Aug 18 1991 17:41 | 162 |
| Article 16037
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 08/15/91
Date: 16 Aug 91 22:27:59 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neil Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 9 - 15, 1991
SPACECRAFT
1. In preparation for the August 12 HGA (High Gain Antenna) cooling turn
activity, commands were sent on August 9 to cycle two electrical heaters
(external shunt heater and PCT (Photometric Calibration Target) heater) off/on
to enhance thermal conditioning of the RPM (Retro Propulsion Module) tanks to
seat the pressure regulator. The heaters were turned on for the planned
duration of 34 hours and then turned off.
2. The HGA cooling turn sequence was transmitted to the spacecraft on
August 9. Subsequently, commands were sent to turn off the PWS (Plasma Wave)
magnetic field sensor heater and disable its thermal control monitor. Turning
off the PWS heater (3 watt) is expected to enhance the HGA tower contraction
and improve the chances of "freeing" stuck ribs.
3. The second HGA cooling turn was performed on August 12. The turn, which
pointed the spacecraft's -Z axis about 165 degrees from the sun to shade the
entire HGA, was performed using the P-thrusters. Spacecraft performance
throughout the turn was normal; the turn angle achieved was about 12 mrad from
the planned 165 degrees. Having reached attitude, the spacecraft was then
commanded to the all-spin mode for the duration of the nominally planned
50-hour "cold-soak". "Quick look" review of actual temperatures indicated all
were within the design flight allowable limits or limits waived specifically
for the turn. Temperatures along the antenna tower were colder than those
observed during the July 10 turn but not as cold as predicted. After about 34
hours at the cooling attitude, concern was expressed for Probe temperatures.
Based on a projected estimate at 50 hours, the Probe shelf temperature (T2)
could reach 28.5 degree C compared with the 27 degree C agreed-to limit.
Subsequent careful review of the data by HAC/AMES (HAC = Hughes Aircraft
Company) personnel concluded that a temperature of 28.4 degree C was not a
serious threat to the Probe and that the sequence could continue, as planned,
without interruption.
At about midnight on August 14, the spacecraft initiated the sequence
controlled sun acquisition maneuver using the P-thrusters; spacecraft
performance throughout this activity was normal. However, during the activity,
the P2A thruster temperature momentarily went to 255 DN indicating an open
interface between the transducer and the CDS (Command Data Subsystem) input.
It is likely that the temperature transducer exhibited an intermittent open
circuit, similar to that observed prior to the total failure of the P1A, Z1A
and L2B transducers. About three hours before the start of the sun acquisition
and about two hours before the stored sequence command, a real time command was
sent to turn on the PWS magnetic field sensor heater in preparation for PWS
main power turn on about 11 hours later. The PWS main power turn on was
accomplished via a Delayed Action Command (DAC) which was sent to the
spacecraft on August 9.
Nearly 14 hours after the completion of sun acquisition, commands were
sent on August 15 to configure the spacecraft to a power state consistent with
cruise and the EE-2 (Earth-Earth 2) prime sequence expected initial state.
As expected, there was no real time indication during or after the cooling
turn activity that the HGA ribs may have released. Subsequent to the completion
of sun acquisition, the spacecraft was returned to the dual-spin mode and the
gyros were powered on in order to collect some preliminary wobble angle data.
The most reliable indicator of rib release will come from spacecraft wobble
angle data which will be collected on August 17. In addition to the wobble
angle information, a 2.7-degree turn to point the spacecraft 4 degrees off
sun is scheduled for August 17. This turn permits collection of the sun gate
data to determine if the antenna rib positions changed as a result of the turn.
4. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement fluctuated about 7 DN and now reads 44.6 volts; the DC measurement
fluctuated 3 DN and now reads near 16.6 volts. All other power telemetry
and subsystem telemetry is normal.
5. The Spacecraft status as of end of day August 15 was as follows:
a) System Power Margin - 55 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.11 rpm/spin detector
d) Spacecraft Attitude Sun Point Angle - approximately
0.5 degree (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except EUV, PLS,
PPR and NIMS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 226 hours
P2A thruster temperature reading 255DN
TRAJECTORY
As of noon (PDT) Thursday, August 15, 1991, the Galileo
Spacecraft status was as follows:
Distance from Earth 157,288,370 miles
Distance from Sun 185,307,290 miles (1.98 AU)
Heliocentric Speed 40,700 miles per hour
Distance from Gaspra 33,614,900 miles
Round Trip Light Time 27 minutes, 58 seconds
SPECIAL TOPICS
1. As of August 15, 1991, a total of 5572 real-time commands have been
transmitted to Galileo. Of these, 1911 have been pre-planned in the sequence
design and 3661 were not. In the past week, a total of 79 real time commands
were transmitted; 7 were pre-planned, and 72 were not. Major commanding
activities included heater power reconfiguration in support of the cooling
turn, numerous commands to reset the loss timer consistent with link
performance predictions and post-turn power configuration commands.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
Article 16039
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/16/91
Date: 16 Aug 91 23:21:48 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 16, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry data at 40 bps.
Early today, the spacecraft completed the planned post-HGA (High
Gain Antenna) turn star scanner checkout; no bright particles were
detected. The star scanner sun shutter was "permanently" opened.
Later today, a mini sequence of commands will be sent to the
spacecraft. This sequence contains the commands necessary to perform
the planned post-HGA wobble ID and SITURN activities to determine if
the HGA ribs released.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.420 | GALILEO Update - August 19 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Aug 20 1991 16:35 | 36 |
| Article 16089
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/19/91
Date: 20 Aug 91 04:30:53 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 19, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry data at 40 bps. Over the
weekend, the spacecraft collected the post-HGA-turn wobble data and
completed the SITURN to determine if the HGA ribs released. Data
processing and analysis from these activities is in process.
Early today, a mini sequence of commands was sent to update
several attitude control operating parameters in the on-line memory.
These flight software parameter updates are needed to meet the GASPRA
encounter pointing accuracy requirements. The parameter updates for
the off-line memory are planned for August 22.
Also today, the routinely planned SSI (Solid State Imaging) MRO
(Memory Readout) was completed to evaluate the engineering health and
safety of the SSI instrument.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.421 | Time to rev up that relay satellite | MTWAIN::KLAES | All the Universe, or nothing! | Tue Aug 20 1991 18:41 | 93 |
| Article 1621
From: clarinews@clarinet.com (WILLIAM HARWOOD, UPI Science Writer)
Newsgroups: clari.tw.space
Subject: Galileo antenna still stuck
Date: 20 Aug 91 17:23:01 GMT
A third attempt to free a jammed antenna crippling NASA's $1.4
billion Galileo Jupiter probe failed, officials said Tuesday, but
engineers vowed to continue trying to fix the costly spacecraft before
it reaches its target in 1995.
Galileo's gold-plated $3.7 million ``high-gain'' antenna
failed to open properly April 11, throwing the showcase mission into
jeopardy. Without the antenna, Galileo would be unable to transmit
more than a fraction of the pictures and other data it was built to
collect about the solar system's largest planet.
An attempt to free the antenna in June by warming it in direct
sunlight failed. But additional analysis indicated the hung-up
mechanism would pop open if a central support column could be chilled
enough to cause the proper amount of contraction, releasing two of 18
ribs preventing the umbrella-like dish from opening.
The first such ``chill out'' was conducted last month, but the
antenna refused to budge. Last week, the nuclear-powered Galileo was
reoriented, shading the antenna from the warmth of the sun for a
longer period -- 50 hours. At the same time, engineers turned off
spacecraft heaters to chill it even more.
Engineers spent the weekend analyzing telemetry from the
spacecraft to find out if the maneuver worked.
It did not.
Because part of the spacecraft spins, a partially open antenna
causes a minute wobble detectable in telemetry monitored on Earth. If
the antenna popped free, its shape would be more symmetrical and the
wobble would decrease accordingly.
But project manager William O'Neil at NASA's Jet Propulsion
Laboratory in Pasadena, Calif., said the latest effort to free the
antenna had failed.
``We didn't get cold enough,'' he said. ``We have now
processed our diagnostic tests on the spacecraft and determined that
there's been no change in the antenna configuration. We didn't get
nearly as cold as we had hoped.''
Engineers had hoped to chill the central column to around
minus 274 degrees Fahrenheit. But the lowest temperature actually
obtained was around minus 238 degrees.
``It's a disappointment that it didn't work this time,''
O'Neil said. ``But the fact that the temperatures did not get to where
we had hoped gives us some reason for optimism.
``Had they gotten to what we were hoping for and we hadn't
gotten a favorable result, that would have been very disappointing.
We've just got to get it colder.''
Galileo, the most sophisticated -- and costly --
interplanetary spacecraft ever built, was launched from the shuttle
Atlantis on Oct. 18, 1989. It currently is sailing away from the sun,
on course for an Oct. 29 asteroid flyby before looping back toward
Earth for a velocity-boosting flyby next year that will fling the
probe on toward Jupiter.
If all goes well, Galileo will slip into orbit around the
giant planet in July 1995, dropping a probe into Jupiter's atmosphere
before beginning a two-year study of the solar systems's largest
planet and its many moons.
But the high-gain antenna is crucial to Galileo's success.
Without it, Galileo's smaller low-gain antenna would need some 12 days
to transmit a single image of Jupiter, two years to beam back a
maximum of 60 or so pictures compared to the thousands it was designed
to take during the same period.
Despite three failures, O'Neil said an additional attempt to
free the antenna will be made in December when Galileo is even farther
from the Sun. And if that fails, engineers will try the opposite approach.
``Following the December effort, we would also envision as we
come back to Earth in December of '92 ... if we have not had success
by that time we might also try heating the tower,'' O'Neil said.
``There's no penalty for pushing the other direction.''
But if the stuck ribs warping the 75-pound dish antenna refuse
to budge even after repeated attempts to coax them loose in the months
ahead, NASA would be faced with a potential space failure more
devastating than the well-publicized optical flaws hobbling the $1.5
billion Hubble Space Telescope.
|
| 560.422 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Tue Aug 20 1991 19:43 | 18 |
| Far fetched idea #57,234,198:
I wonder if
1. Ulysses has appropriate receivers, transmitters, and data paths such that it
could be used as a Galileo data relay.
2. Ulysses would be anywhere near Jupiter after its first complete orbit of the
sun
3. Galileo would still be alive and running after U completes a full orbit.
If all of these things are true, some experiments could presumably be scheduled
to happen around the time the U was coming near Jupiter. Since U's main mission
is to examine the out-of-ecliptic space, presumably it would not miss to much
of importance when it is near Jupiter (and therefore near the ecliptic)
Burns
|
| 560.423 | NASA plans another attempt to resolve Galileo antenna problem | PRAGMA::GRIFFIN | Dave Griffin | Tue Aug 20 1991 23:31 | 24 |
| RELEASE: 91-135 (8/20/91)
The cooling turn performed last week by the Galileo spacecraft did not
result in low enough temperatures to release the few antenna ribs apparently
bound by friction to the antenna's central tower, Galileo project officials
said today.
Another cooling turn is being planned for December 1991 when Galileo is
farther from the sun. Additional actions will be taken at that time to cool
the antenna tower further. These cooling turns are part of a series of steps
project officials believe will be required ultimately to deploy the antenna.
The officials said each step yields valuable data to help with the design of
spacecraft actions in the next step.
For the next 2 months, the Galileo flight team will concentrate on the
final preparations for Galileo's Oct. 29 encounter with the asteroid Gaspra.
This will be the first spacecraft asteroid encounter.
Galileo's high-gain antenna is not essential for mission operations until
the spacecraft is in orbit around Jupiter in December 1995, project officials
said.
Galileo is managed for NASA's Office of Space Science and Applications by
the Jet Propulsion Laboratory, Pasadena, Calif.
|
| 560.424 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Wed Aug 21 1991 15:44 | 5 |
| FWIW, this week's AvWeek has a close-up picture of the pins on the antenna
rib. (Presumably of a ground test article) I say FWIW, because the shot is so
close up, I could not make head nor tail of it.
Burns
|
| 560.425 | Me-too | TUCKER::BIRO | | Wed Aug 21 1991 16:36 | 4 |
| re -1
gee I am not alone, can anyone explan the AvWeek close up photo...
thanks john
|
| 560.426 | GALILEO Updates - August 20-21 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Aug 21 1991 19:51 | 56 |
| Article 16109
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/20/91
Date: 21 Aug 91 05:17:47 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 20, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry data at 40 bps. Today, a
mini-sequence of commands will be sent to perform the periodically
required RPM (Retro Propulsion Module) 10-Newton thruster maintenance
activity.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
Article 16120
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/21/91
Date: 22 Aug 91 02:00:49 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 21, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry data at 40 bps.
Yesterday, the spacecraft completed another RPM (Retro Propulsion
Module) 10-Newton thruster "flushing" activity.
Today, commands will be sent to reposition the RTG booms to reduce
the wobble angle in support of meeting GASPRA pointing requirements.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.427 | So near, yet so far.... | TROOA::PIERCE | awk!! I've been greped! | Wed Aug 21 1991 22:30 | 11 |
|
Sheesh, this is frustrating.
Maybe on future high priced robot probes, they could add a cheapy robot
arm that could reach most places on the probe. Equip with a camera, and
an easy to reach tool kit of vice grips, screwdriver and a rubber
mallet.
I'm sure if a LGM just dropped by and gave it a good kick, it would
deploy!
|
| 560.428 | | LHOTSE::DAHL | Customers do not buy architectures | Thu Aug 22 1991 12:39 | 10 |
| RE:<<< Note 560.424 by DECWIN::FISHER "Klingons don't "enter a relationship"...they conquer" >>>
My guess is that the pin is the gold/brown/yellow stub of a thing which is
just barely visible, protruding out of the socket/hole on the right side of the
picture where the rightmost (of the two) shiny silver rods/booms is emanating
from. The pin appears to be almost fully inside the socket/hole, and to be
attached to the main frame, rather than to be out on and attached to the boom.
Whadday think?
-- Tom
|
| 560.429 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Thu Aug 22 1991 15:14 | 17 |
| BTW, for anyone at SpitBrook without access ot AvWeek, I have that picture
hanging outside my office (ZK3-4/W20, pole H12) for the moment.
I think I am beginning to understand it a bit. First, the pins are really
standoffs which hold the antenna rib away from the central post. It looks
like only a (small?) part of the pins actually go into the sockets. Second,
if the umbrella analogy holds, there are ribs which run along the surface of
the antenna reflector and spokes, which would run from the end of a rib across
space to the center post. I think maybe one of these spokes is visible.
What I can't see is the scale. It looks like the rib is a huge i-beam like
thing. It may be that we are looking from the spacecraft up under the dish
head-on at the end of a rib.
Whew...really hard to figure out.
Burns
|
| 560.430 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Thu Aug 22 1991 15:24 | 17 |
| oops...I wrote .429 before reading .428:
I think the pins are the two silver things because of the caption, which says
"...(the) standoff pins (protruding from stowed antenna rib at right) to seize in
their v-groove and conical receptacles on the antenna tower of Galileo"
One of the silver things is in a V-shaped groove, the other in a cone-shaped
thing. I therefore assume that the black which is most of the lower left
part of the pix is the antenna tower. I further assume that the goldish-brownish
thing taking up most of the upper right of the pix is the rib. I think that
the bright silver in the middle is an artifact of a flash on an end surface of
the rib. I'm thinking that the small silver thing between the two pins is
what I called a spoke earlier, but I can't tell if it is attached to the tower.
I would think that spokes should be connected to a ring containing the motor
which drives the ring up the tower.
Burns
|
| 560.431 | GALILEO Update - August 21 (#2) | MTWAIN::KLAES | All the Universe, or nothing! | Thu Aug 22 1991 17:17 | 44 |
| Article 16126
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 08/21/91
Date: 22 Aug 91 06:12:32 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
August 21, 1991
The Galileo spacecraft is about 166 million miles from Earth;
round-trip communication is now almost 30 minutes. It is 187 million
miles from the Sun, and its speed in orbit is 40,100 miles per hour.
The spacecraft health and performance remain excellent with the
exception of the partly deployed high-gain antenna, whose condition
was not changed by the "cold soak" performed last week. The spacecraft
is in the dual-spin mode, with the upper part rotating at 3.15 rpm and
the lower part in a fixed orientation.
The cooling turn operation was designed to chill and shrink the
antenna central tower by pointing the antenna away from the Sun for 50
hours and turning off some heat-producing elements nearby. Shrinking
the tower was intended to free about three antenna ribs believed to be
stuck by friction in the closed position. Another cooling turn will be
planned after Galileo's October 29 encounter with the asteroid Gaspra.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.432 | GALILEO Update - August 22 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Aug 22 1991 20:18 | 34 |
| Article 16145
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/22/91
Date: 23 Aug 91 00:48:47 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 22, 1991
The Galileo spacecraft is operating normally in the dual-spin mode;
transmitting coded telemetry at 40 bps.
Today the AACS (Attitude and Articulation Control Subsystem) off-line
memory will be loaded with the SCALPS parameters. This memory load will
reestablish complete functional redundancy and assure that both AACS memories
can support the GASPRA attitude and instrument-pointing requirements.
Tomorrow, the Spacecraft Telemetry Modulation Unit will be commanded to
the low frequency subcarrier mode and the data rate alternately commanded to
10 bps and 40 bps to test spacecraft to DSN (Deep Space Network) end-to-end
performance in this mode. This configuration will be used during the GASPRA
encounter to provide the best possible DSN support.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.433 | Is this worth a try? Sort of a long dist. kick. | HYEND::POPIENIUCK | | Thu Aug 22 1991 20:29 | 14 |
| How about a strictly non-technical possible solution. The cold soaking
hasn't worked thusfar and from what I read it will be tried again in
December. I wouldn't put much stock in it working then either. How
about just giving the probe a "kick in the side?" How you say? How
about combining a cold soak with some sort of spinning or tumbling
manoeuver (the manoeuver would immediately follow the cold soak).
Would this exert enough extra stress from some angular momentum to pop
things loose without hurting the probe? (I don't know the geometries
involved or even if this is possible or maybe it would cause more harm
than good, but I haven't seen any other ideas coming along either
except maybe the relay satellite.)
Any opinions on this idea? (NASA, if it works, I'm a consultant and my
fee is only 1% of Galileo's cost. Such a bargain ;^)
|
| 560.434 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Thu Aug 22 1991 20:47 | 17 |
| It seems like some mechanical action at the same time as the cold soak would
make sense, but I think that spinning would not work. The reason: The tower
is along the axis of spin. Thus there would not be much centripital force
on the pins. In fact there would probably be a lot more on the partially
deployed antenna, which would pull on the pins in the "wrong" direction.
I wonder if some SDI genii (plural of genius) might be able to crank up a
laser and heat up the right part of G as it goes by Earth. (I know...it's going
too fast, etc etc).
"This looks like a job for S-U-P-E-R-M-A-N!!"
(BTW did you ever wonder when he saved rockets and stuff, why we even bothered
to have them? I mean after all, couldn't s-man just go out and do whatever the
rocket was intended to do?)
Burns
|
| 560.435 | Compensate for distortion? | CLOSUS::J_BUTLER | L'audace, toujour l'audace! | Thu Aug 22 1991 22:17 | 16 |
| Not being greatly knowledgeable in the area of signal propagation
does any one think they might be able to get a usable signal
from the partially deployed antenna?
It is out of "round," but signals should be able to get out.
Would it be possible to analyze the antenna's new properties
and compensate by orienting Galileo in such a way that max
signal would be heading toward Earth? I would suspect that
some smart "signal mechanics" would be able to do a computer
simulation and possibly use the antenna down here to run some
tests and come up with something better than 40bps out of the
HGA.
Any thoughts?
John B.
|
| 560.436 | | HELIX::MAIEWSKI | | Fri Aug 23 1991 02:18 | 4 |
| Most likely, what ever signal got out would be weaker than what they get from
the low gain antenna.
George
|
| 560.437 | Use other receivers? | CLOSUS::J_BUTLER | L'audace, toujour l'audace! | Fri Aug 23 1991 12:14 | 10 |
| Thanks!
Might it be possible to divert other assets (such as the VLA) to
acquire the weaker signals? Obviously, they couldn't be dedicated
solely to Galileo, but it might result in more usable data than
60 pics in 12 years.
?
jb
|
| 560.438 | Yup, active antennas is the way to go | TUCKER::BIRO | | Fri Aug 23 1991 12:58 | 24 |
| Yes, they could put several antennas sites link together,
they have alreadey demo this before, this would give a
receiving antenna about the size of the earth.
This would allow for a higher data transfer rate, plus they could look at
better data commpression methods, and I think it would best to send
quick low resolution averaged data block back first. This would help
to sort threw the data for the best use of the high resolution data.
But I think NASA should take this for a good lesson, one we have told
the Soviets about and did not do ourself. For deep space
studies we should first send a data relay satellite into orbit of the
target. This would allow the scientific payload to use more of
its weight for experiment plus it would be needed before any
man mission should be tried. This has an extra benifit that the
extra weight saving could be use for a return sample mission.
john
|
| 560.439 | GALILEO Updates - August 16-22 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Aug 23 1991 14:43 | 137 |
| Article 16155
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 08/22/91
Date: 23 Aug 91 09:10:15 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neil Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 16 - 22, 1991
SPACECRAFT
1. A mini-sequence of commands was sent on August 17 to collect wobble angle
information and perform a 2.7 degree SITURN to permit sun gate obscuration data
collection. These data are the most reliable information to determine if the
antenna ribs released during last week's cooling turn. Analysis of the flight
data indicate that the wobble angle and sun gate signal obscuration information
did not change as a result of the cooling turn; no evidence of rib release was
observed.
2. Another mini-sequence of commands was set on August 19 and August 22 to
update several attitude control performance parameters. These software
parameter updates are needed to meet the GASPRA encounter pointing accuracy
requirements. The parameters were updated in the on-line and the off-line
attitude control memory on August 19 and 22, respectively.
3. The RPM (Retro Propulsion Module) 10-Newton thrusters were "flushed" again
on August 20 using a mini-sequence. All the thrusters except the P-thrusters
were "flushed" during this activity. The P-thrusters were not exercised during
this activity since they are used periodically for performing sun point and
SITURN activities; spacecraft performance throughout the "flushing" activity
was normal.
4. Commands were sent on August 21 to reposition the +x and -x RTG booms and
measure the resultant wobble angle. This effort is the first of three planned
opportunities to reduce the wobble to meet Gaspra pointing requirements;
ultimately the wobble angle is expected to be reduced from about 3.5 mrad to
near 0.5 mrad. Preliminary analysis of this first wobble reduction activity
indicates the wobble was reduced to nearly 1 mrad.
5. The AC/DC bus imbalance measurements exhibited some minor change. The AC
measurement fluctuated 2 DN and made 45.03 volts; the DC measurement remained
steady at 16.6 volts. All other power telemetry and subsystem telemetry are
normal.
6. The Spacecraft status as of end of day August 22 was as follows:
a) System Power Margin - 56 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude Sun Point Angle - approximately
5.4 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except EUV, PLS,
PPR and NIMS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 236 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. Project reviewed and approved the preliminary sequence and command
generation for the EE-2 (Earth-Earth 2) prime sequence on August 20. The EE-2
prime sequence is planned to be sent to the spacecraft on August 28. The
sequence will control spacecraft activities from September 3 to October 28.
Major activities include four OPNAV observations, three SITURNs, three RPM
flushing activities, sixteen SSI (Solid State Imaging instrument) MROs (Memory
Readouts) and windows for TCM-11 (Trajectory Correction Maneuver 11) and
TCM-12.
GDS (Ground Data Systems):
1. The Project Change Board (PCB) approved a Software Change Request (SCR) to
modify the DMS (Data Management Subsystem) Memory Readout (DMSMRO) processing
algorithm in the MCCC Telemetry Subsystem (MTS). The DMSMRO algorithm will be
used by the MTS to process and capture the Gaspra optical navigation pictures.
This change provides a capability for retaining data that might otherwise be
lost during marginal downlink conditions. Pending successful completion of the
acceptance test and delivery reviews, the modified MTS software is tentatively
scheduled for a waiver delivery on Friday, August 30.
TRAJECTORY
As of noon (PDT) Thursday, August 22, 1991, the Galileo Spacecraft status was
as follows:
Distance from Earth 167,212,530 miles
Distance from Sun 187,694,620 miles (1.99 AU)
Heliocentric Speed 40,000 miles per hour
Distance from Gaspra 30,246,290 miles
Round Trip Light Time 29 minutes, 46 seconds
SPECIAL TOPICS
1. As of August 22, 1991, a total of 5711 real-time commands have been
transmitted to Galileo. Of these, 1911 have been pre-planned in the sequence
design and 3800 were not. In the past week, a total of 139 real time commands
were transmitted; none were pre-planned. In addition 1809 mini-sequence
commands have been transmitted since March 1991, including 99 this week.
Major commanding activities this week included Star Scanner checkout, star
shutter open, post HGA turn wobble identification and SITURN, attitude control
parameter updates (SCALPS), RPM flushing, and a wobble compensation and
identification.
2. The fifth meeting of the special HGA anomaly review board was held on
August 22, 1991. Results from the last cooling turn were presented and
reviewed. Additionally, results of the "cold box" test, friction tests, and
further rib deployment tests were presented.
As a consequence of the modeling and antenna testing completed, the most
likely condition is that 3 ribs are "stuck" in the stow position, no damage has
occurred to the motor drive mechanism, and no structural failure has occurred
in the drive train. Therefore, if the ribs can be "freed", full capability to
open the HGA is available.
HGA preliminary action plan options were discussed; the next contemplated
action with the spacecraft will be post-Gaspra and include performing another
cooling turn near aphelion in December 91 and possibly inducing mechanical
shock via retraction/deployment of the LGA-2 (Low Gain Antenna-2) boom.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.440 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Fri Aug 23 1991 15:30 | 9 |
|
> HGA preliminary action plan options were discussed; the next contemplated
>action with the spacecraft will be post-Gaspra and include performing another
>cooling turn near aphelion in December 91 and possibly inducing mechanical
>**shock via retraction/deployment of the LGA-2 (Low Gain Antenna-2) boom.
Isn't it nice that they pay attention to our brilliant ideas? :-)
Burns
|
| 560.441 | | FASDER::ASCOLARO | Tardis Del., When it has to be there Yestdy. | Fri Aug 23 1991 16:20 | 19 |
| Well to me there was one bright spot:
> As a consequence of the modeling and antenna testing completed, the most
>likely condition is that 3 ribs are "stuck" in the stow position, no damage has
>occurred to the motor drive mechanism, and no structural failure has occurred
>in the drive train. Therefore, if the ribs can be "freed", full capability to
>open the HGA is available.
So far there is no damage. This is goodness. ALL they have to do now
is free the thing. Maybe it will work at perihelion ....
I wonder why the temp didn't get as cold as their model suggested?
On another note, I am surprised that the HGA status is the LAST topic
to be covered. In all honesty, I would think that it should be first.
I mean, its like the whole mission is resting on this thing coming
unglued!
Tony
|
| 560.442 | | STAR::HUGHES | You knew the job was dangerous when you took it Fred. | Fri Aug 23 1991 17:53 | 18 |
| re .441 (why didn't it get as cold as expected)
There are a lot of aspects of spacecraft design based on 'this is the
way we have always done it' rules that have never been formally proven
other than they appeared to have worked in the past.
Thermal control seems to be one of those. With redundant systems all
working to keep the spacecraft within a specified temp range, no one is
certain what temperature will be reached if all of the control systems
are bypassed.
As an old example of this, Australis-OSCAR V used a passive thermal
control scheme, a paint pattern that had been used by Goddard for
years, apparently successfully. However, they always used it as a
backup to an active thermal control system and when it was used as a
primary it didn't work as expected.
gary
|
| 560.443 | GALILEO Update - August 23 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Aug 23 1991 20:20 | 38 |
| Article 16165
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/23/91
Date: 23 Aug 91 23:38:49 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 23, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, attitude control software parameter updates to support the
GASPRA encounter were completed in the off-line memory. Memory parameter
updates are now complete in both memories and full functional redundancy is
available.
Tomorrow, commands will be sent to alternately change the telemetry
modulation unit between high and low frequency subcarrier to characterize the
spacecraft DSN (Deep Space Network) downlink end-to-end system performance at
10 bps and 40 bps. This mode will be used during the GASPRA encounter.
On Sunday, a SITURN is scheduled to orient the spacecraft about 3 degrees
off sun point in preparation for the SSI (Solid State Imagine) cover deployment
planned for September 5. Also, on Sunday the EUV (Extreme Ultraviolet
Spectrometer) instrument will be powered on.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.444 | GALILEO Update - August 26 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Aug 27 1991 13:07 | 65 |
| Date: 27 Aug 91 00:58:04 GMT
From: elroy.jpl.nasa.gov!kelvin.jpl.nasa.gov!baalke@decwrl.dec.com (Ron Baalke)
Subject: Galileo Update - 08/26/91
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 26, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Over the weekend, the spacecraft and DSN (Deep Space Network)
completed its telemetry performance characterization at 10 and 40 bps
using the spacecraft's telemetry modulation unit low frequency
subcarrier (22.5kHz) for telemetry data return; data analysis is in
process. Additionally, the spacecraft completed:
a) another wobble compensation/identification activity to reduce
the wobble angle to meet GASPRA pointing requirements
b) a SITURN to reduce the spacecraft's off-sun attitude from about
6 degres to 3 degrees in preparation for SSI (Solid State
Imaging)cover release on September 5.
c) another SSI memory readout to verify instrument health and
safety, and
d) powering on the EUV (Extreme Ultraviolet Spectrometer) instrument.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
Date: 27 Aug 91 11:03:53 GMT
From: elroy.jpl.nasa.gov!kelvin.jpl.nasa.gov!baalke@decwrl.dec.com (Ron Baalke)
Subject: Re: Unsticking the High Gain Antenna
In article <1991Aug27.023141.14513@news.iastate.edu>,
F1.DAO@isumvs.iastate.edu (David Oesper) writes...
>If cooling the Galileo high-gain antenna down again doesn't work,
>has anybody thought of gently "shaking" the structure using
>thrusters or gyros? A little acceleration might just work, if
>it can be done without damaging the spacecraft and systems.
>I realize this is a little more extreme than cooling the HGA down,
>but what else can be done if that doesn't work?
At the next cooling turn in December, one of the Low Gain Antennas
will probably be retracted and extracted back out a couple of times to
get some shaking going. There is also the option of turning on the
deployment motors a second time; they've been sitting idle since the
initial deployment attempt in April.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.445 | GALILEO Update - August 28 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Aug 29 1991 12:19 | 67 |
| Date: 29 Aug 91 00:11:06 GMT
From: (Ron Baalke)
Subject: Galileo Update - 08/28/91
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
August 28, 1991
The Galileo spacecraft is about 176 million miles from Earth;
round-trip communication time has now reached 31 minutes 29 seconds.
Distance from the Sun is almost 190 million miles.
The spacecraft health and performance continue to be generally
very good; efforts to unfurl the high-gain antenna have been suspended
for a time. Late tonight Galileo's ground crew will transmit a long
operating sequence to the spacecraft that will control spacecraft
activities from September 3 to October 28, the day before the Gaspra
planetoid encounter.
During this period, Galileo will perform the final trim maneuvers
to adjust the flyby conditions, and will collect optical navigation
data to verify and refine Gaspra's location. The actual scientific
observations and other encounter activities will be contained in a
separate sequence covering the few days from October 28 through
November 4, to be sent in late October.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
Date: 29 Aug 91 00:20:27 GMT
From: (Ron Baalke)
Subject: Galileo Update #2 - 08/28/91
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 28, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Yesterday, the planned attitude control software updates to both
memories were completed.
Late today, between 8 p.m. (PDT) and midnight, the EE-2
(Earth-Earth 2) prime sequence memory load is scheduled to be
transmitted to the spacecraft. This sequence controls spacecraft
activities from September 3 to October 28.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.446 | GALILEO Update - August 29 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Aug 29 1991 20:29 | 29 |
| Article 16380
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Gailleo Update - 08/29/91
Date: 30 Aug 91 01:16:44 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 29, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
The EE-2 (Earth-Earth 2) prime sequence memory load was
transmitted and received by the spacecraft late last night. No
anomalies or incidents were reported.
Today and tomorrow, no spacecraft activity is planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.447 | GALILEO Updates - August 23-29 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Aug 30 1991 13:00 | 120 |
| Date: 30 Aug 91 06:13:21 GMT
From: elroy.jpl.nasa.gov!kelvin.jpl.nasa.gov!baalke@decwrl.dec.com (Ron Baalke)
Subject: Galileo Update #2 - 08/29/91
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 23 - 29, 1991
SPACECRAFT
1. A special telecommunication spacecraft to DSN (Deep Space Network)
end-to-end test was performed on August 23 to characterize the
telemetry link performance at 10 bps and 40 bps using the spacecraft's
low frequency subcarrier (22.5 khz). To date the spacecraft's high
frequency subcarrier (360 khz) has been used exclusively for data
return. Preliminary results indicate that link performance
improvements on the order of 0.7 to 1.5 db have been observed
depending on the spacecraft data rate and Telemetry Processing
Assembly (TPA) being used. Additional testing is being planned to
further characterize 1) the telecom performance improvements, 2) to
understand any timing differences between the Type A and B TPAs, and
3) to establish the final Gaspra configuration.
2. Another attitude control wobble compensation and identification
activity was completed on August 24 by repositioning the RTG booms.
This was the second of three planned activities to reduce the wobble
angle to less than 0.5 mrad to meet Gaspra pointing requirements.
Results indicate the wobble was reduced from about 0.9 mrad to less
than 0.3 mrad. Since this wobble meets that needed for the Gaspra
pointing, the third wobble compensation will not be performed.
3. Commands were sent on August 24 to perform an SSI (Solid State Imaging)
memory readout (MRO) to verify the instrument health and safety.
4. The spacecraft performed a 3-degree SITURN on August 25 to reduce
the sun lagging attitude from about 6 degrees to 3 degrees in
preparation for the SSI cover deploy activity planned for September 5.
5. The EUV (Extreme Ultraviolet Spectrometer) instrument was powered
on August 25 and memory readouts performed. Based on EUV analog
telemetry and the MRO data, the EUV is operating normally.
6. The EE-2 (Earth-Earth 2) prime sequence memory load was
transmitted and received by the spacecraft on August 29. This
sequence is planned to go active on September 3 and controls all
spacecraft activities to October 28. This sequence includes many
activities including the SSI cover jettison, four optical navigation
observations, three RPM (Retro Propulsion Module) flushing events, and
windows for TCM-11 (Trajectory Correction Maneuver 11) and TCM-12 on
October 9 and October 24, respectively.
7. The AC/DC bus imbalance measurements exhibited some minor change.
The AC measurement fluctuated 2 DN and now reads 44.8 volts; the DC
measurement increased 2 DN and now reads 16.8 volts. All other power
telemetry and subsystem telemetry are normal.
8. The Spacecraft status as of end of day August 29 was as follows:
a) System Power Margin - 56 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude Sun Point Angle - approximately
3.9 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS,
PPR and NIMS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 288 hours
Time To Initiation - 288 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. Project reviewed and approved the final sequence and command
generation for the EE-2 prime sequence on August 28.
2. Project reviewed and approved the cruise plan for the EE-4
sequence on August 27. The EE-4 sequence will control spacecraft
activities from November 4 to February 17, 1992.
3. Project reviewed the ICAP for the EE-5 sequence on August 29; EE-5 will
control spacecraft activities from February 17 to April 27.
TRAJECTORY
As of noon (PDT) Thursday, August 29, 1991, the Galileo Spacecraft status was
as follows:
Distance from Earth 177,100,950 miles
Distance from Sun 189,963,120 miles (2.01 AU)
Heliocentric Speed 39,340 miles per hour
Distance from Gaspra 26,956,440 miles
Round Trip Light Time 31 minutes, 32 seconds
SPECIAL TOPICS
1. As of August 29, 1991, a total of 5757 real-time commands have
been transmitted to Galileo. Of these, 1911 have been pre-planned in
the sequence design and 3846 were not. In the past week, a total of
46 real time commands were transmitted; none were pre-planned. In
addition 1903 mini-sequence commands have been transmitted since March
1991, including 94 this week. Major commanding activities this week
included the telecommunication low frequency subcarrier test, attitude
control flight software parameter updates, SITURN and EUV turn on, wobble
compensation and identification, and EE-2 prime sequence memory load.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.448 | | HELIX::MAIEWSKI | | Tue Sep 03 1991 17:16 | 34 |
| Hmmmm, did something new go wrong or did they just realize that the
old wording was a bit silly under the circumstances?
George
GALILEO MISSION STATUS
August 21, 1991
.
.
.
The spacecraft health and performance remain excellent with the
^^^^^^^^^
exception of the partly deployed high-gain antenna, whose condition
was not changed by the "cold soak" performed last week.
.
.
.
GALILEO MISSION STATUS
August 28, 1991
.
.
.
The spacecraft health and performance continue to be generally
very good; efforts to unfurl the high-gain antenna have been suspended
^^^^^^^^^
for a time.
|
| 560.449 | GALILEO Updates - August 30 and September 3 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Sep 03 1991 22:24 | 62 |
| Article 16442
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 08/30/91
Date: 31 Aug 91 06:19:46 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 30, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Today, commands will be sent to put the spacecraft into the
all-spin mode in preparation for next week's SSI (Solid State Imaging)
cover jettison activity planned for September 5. Also today commands
will be sent to perform an imaging instrument (SSI) memory readout
activity to verify the instrument's health and safety.
Over the 3-day weekend, no spacecraft activities are planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
Article 16523
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/03/91
Date: 4 Sep 91 02:55:58 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 3, 1991
The Galileo spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 40 bps.
Today, the EE-2 (Earth-Earth 2) prime stored sequence will go
active as planned. This is the first stored sequence control of the
spacecraft since it went into safing in March 1991. Tomorrow, a USO
(Ultra Stable Oscillator) radio frequency test will be performed. On
Thursday, the imaging instrument (SSI) cover jettison activity is
scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.450 | Light Robot Arm Craft !!! | MAYDAY::ANDRADE | The sentinel (.)(.) | Thu Sep 05 1991 14:24 | 22 |
|
Considering that Galileo costs $1 Billion, A lot of money can be
justified to get it fixed. In this spirit...
How about sending another robot-craft to fix Galileo's Antena.
Somebody else in this topic mentioned, that all these expensive
deep space craft should have their own robot arm, to take care of
mechanical problems like this. So why not sent out one after the
fact.
Using a standard IUS rocket motor, it should be possible to send a
Very Light Robot Arm after Galileo, when it passes by Earth again.
Have it rendevous in deep space, and unfurl the dammed Antena.....
Designing, Launching, and Operating may be doable in time, and the
costs ... could be kept down to less the $50 million or so. "If the
launch is done as a piggy back to something else." (Thus the rescue
mission would cost 5% of Galileo's cost, wich is not so bad as far
as insurance premiums go).
Gil
|
| 560.451 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Thu Sep 05 1991 15:41 | 3 |
| I doubt you could orbit a toothbrush for $50 million. Sigh. :-(
Burns
|
| 560.452 | Update - September 4 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Sep 05 1991 17:13 | 32 |
| Date: 4 Sep 91 23:20:03 GMT
From: (Ron Baalke)
Subject: Galileo Update - 09/04/91
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 4, 1991
The Galileo spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 40 bps.
Yesterday, the EE-2 (Earth-Earth 2) prime sequence went active.
This is the first stored sequence control of the spacecraft since it
went into safing in March 1991.
Also yesterday, while being tracked by DSS-63 (70 meter Madrid
station), the spacecraft experienced two unexplained CDS (Command Data
Subsystem) lock counts. This was the seventh occurrence of this type
of event; spacecraft operation was not affected.
Today, a USO (Ultra Stable Oscillator) radio frequency test will
be performed. Tomorrow, the imaging instrument (SSI) cover jettison
activity is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.453 | | HELIX::MAIEWSKI | | Thu Sep 05 1991 18:56 | 30 |
| Trying to send something up to fix Galileo would be expensive and risky. It
would be expensive simply because just about everything you launch is
expensive, especially if it has to be designed and built from scratch.
As for Risky, there are many places where it could fail. The launch would
have to be within a small window as Galileo passed. The launch would have to
work. Once they caught up, the arm would have to be able to fix the problem
without ripping the antenna apart. Remember, they have only guessed as to what
the problem is. If it's something more substantial than sticky parts like
something wrapped around the antenna it might be tricky to remove.
If you look at the other choices, they look better by comparison. Sending a
repeater allows a larger launch window and doesn't require close up tricky
work.
Getting the old antenna open would be the best bet if it could be done.
It may be possible considering they haven't tried things like starting the
motor while in cold soak.
And if all that fails, there is still the possibility of running it in a
limited mode and using the "fix" money to launch other probes. In the long run
that may be the most effective since we'd still get a few pictures, the taped
play back of the atmosphere probe (which is probably the most important part of
the mission anyway), and data from other instruments.
Trying to fix it would be something to consider, but when you factor in the
cost and risk and the fact that Galileo will work to some extend without the
antenna, they would have a difficult time getting the funding.
George
|
| 560.454 | | EMDS::SILVERSTEIN | Bob Silverstein | Thu Sep 05 1991 20:16 | 16 |
|
I wonder if the folks at JPL are waiting till the craft gets to
Jupiter. Assuming all the attempts up to that point don't free the HGA,
the orbit insertion burn would probably shake things up a bit more than
retracting and deploying the LGA.
Of course if that doesn't work, then it would probably be to late to
send a repeater up.
Bob
|
| 560.455 | Lots and lots of time... | AKOCOA::CMCCABE | Juvenile Product of the Working Class | Fri Sep 06 1991 13:18 | 14 |
| Given how long the Voyager and Pioneer craft have lasted beyond their
design lifetimes, it seems that they have plenty of time to get a
solution to the HGA problem. It just means that we will have to be
patient until then. After all, we've waited over ten years already,
and the craft is taking a long road to get there. Just as long as we
don't lose science along the way and miss opportunities at Gaspra and
Ida, we should realize that failing an overwhelming popular demand to
explore space agressively, it will go slow. This is just an example of
what we can probably expect to see in our lifetime - underfunded, long,
low-cost travel times, and unexpected glitches to keep us on the edge
of our seats. Keep in mind how Voyager II got started - but weren't
those great pictures from Neptune? Herein lies a fine example of how
bittersweet life really is.
|
| 560.456 | | HELIX::MAIEWSKI | | Fri Sep 06 1991 17:38 | 17 |
| As I understand it, there may be a time limit for Galileo once it arrives at
Jupiter. The plan is for it to deploy the atmosphere probe, relay data from the
probe (which will now have to be stored and played back at low baud), use it's
engine to enter Jovian orbit, then use gravity assist to fly past many of the
moons.
The problem is that this path past the moons has to be worked out ahead of
time. It may be difficult to keep working out schemes where by it doesn't end
up in some semi-useless orbit after a certain amount of time. Also, it may
require a fair amount of fuel to keep nudging it toward new interesting gravity
assists
I understand the original plan was for it to bounce from moon to moon for
something like 20 months. Maybe now they will be planning a different approach
that involves less flyby's per year and more useful fly bys in later years.
George
|
| 560.457 | | FASDER::ASCOLARO | Tardis Del., When it has to be there Yestdy. | Fri Sep 06 1991 18:18 | 20 |
| George,
You have an interesting idea, that is, if the telemetry rate is
reduced, reduce the encounter rate and keep it up for longer, thus
preserving many mission accomplishments, albeit at a slower rate
(probably not a problem as JPL is still doing a lot of analysis of
Voyager data, it takes a long time to sift through a pile of data.).
The problem is of course the rtg's. I have no idea how long they will
supply sufficient power margin, but remember they started decaying in
what 1984? You just don't shut off an rtg when a mission gets
postponed, at least you don't with our current level of technology :-)
I think rtg margin will be more of a limiting item that propellent,
after all they are doing these asteroid flyby's because (I seem to
remember) that their propellent margin was such that they would have to
shut off the instruments and they would still have fuel left, so why
not use the fuel for the asteroid encounters now.
Tony
|
| 560.458 | | EMDS::SILVERSTEIN | Bob Silverstein | Fri Sep 06 1991 20:12 | 11 |
|
And don't forget radiation. This is one of the big concerns at Jupiter.
Voyager determined that there was a lot more than expected. They did
harden Galileo more, but it will take its toll eventually.
Bob
|
| 560.459 | Shake and bake... | TROOA::PIERCE | awk!! I've been greped! | Mon Sep 09 1991 15:51 | 15 |
|
The other day I grabbed by umbrella from tha back seat of my car before getting
out in the rain. I pressed the little "auto open" button, and found that it
jammed in a "partially deployed" position.
Without thinking, I started a twisting motion, at a rate that caused the whole
assembly to oscillate around the long axis.... and pop, out it came. I'm sure
everyone who encounters a stuck auto open umbrella has done the same.
Is there anyway that test article or computer analysis could result in a
thruster sequence to set up that type of motion (maybe in combination with cold
soak & turn on the deployment motor)?
IMHO that resonant type motion would be more effective than just a bump.
|
| 560.460 | | HELIX::MAIEWSKI | | Mon Sep 09 1991 19:27 | 10 |
| They are probably considering all of those things. My guess is that they
probably have a list of things to try and that they are ordering them from
simple to tricky where simple means low risk, low fuel, normal attitude
and tricky means jam the motor on, bang anything that will move, thrash
about, etc.
I'm sure they won't quit until they've tried everything short of ordering
the thing to explode.
George
|
| 560.461 | Hit the brakes and he'll fly right by... | ZENDIA::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Mon Sep 09 1991 19:36 | 4 |
| The best chance for a good jar to the spacecraft is the Jupiter
insertion manuever. I don't know if they'd want to change the
spacecraft configuration at this point but it's certainly the best
planned shake for the ship.
|
| 560.462 | Updates - September 5-6 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Sep 09 1991 19:40 | 201 |
| Date: 6 Sep 91 21:43:50 GMT
From: (Ron Baalke)
Subject: Galileo Update #2 - 09/05/91
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 30 - September 5, 1991
SPACECRAFT
1. The spacecraft was commanded to the all-spin mode on August 30 in
preparation for the imaging instrument's (SSI) cover jettison activity on
September 5.
2. The EE-2 (Earth-Earth 2) prime sequence which was sent to the spacecraft
on August 29 went active, as planned, on September 3. This marks the first
time that spacecraft events are being controlled by a stored sequence since the
safing entry in March 91.
3. A command was sent on September 3 to reset the command loss timer to 288
hours, its planned value for this mission phase.
4. While being tracked by DSS-63 (70 meter Madrid station) on September 3 and
4, two unexpected CDS (Command Data Subsystem) lock change counts were
observed. The telemetry signature was identical to that seen on previous
occurrences; the spacecraft operation was not affected by this event and there
was no indication of a command being received by the spacecraft (see Special
Topic 2).
5. The imaging instrument's (SSI) protective cover jettison activity was
performed, as planned, on September 5. The spacecraft performance throughout
the activity was normal and without incident. The cover jettison pyro event
was verified from pyro engineering telemetry. Within two hours after the
pyro event, the SSI front optics temperature dropped 2 DN providing some SSI
confirmation that the cover is removed.
6. Commands were sent on September 5, after the SSI cover jettison activity,
to select the low frequency subcarrier (22.5 KHZ) for telemetry. Link
performance is expected to increase about 0.25 db using the present Telemetry
Processing Assembly (TPA) equipment.
7. The AC/DC bus imbalance measurements exhibited some minor changes. The AC
measurement fluctuated 2 DN and now reads 44.84 volts; the DC measurement
increased 1 DN and now reads 16.8 volts. All other power telemetry and
subsystem telemetry are normal.
8. The Spacecraft status as of end of day September 5 was as follows:
a) System Power Margin - 55 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/star scanner
d) Spacecraft Attitude Sun Point Angle - approximately
5.8 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR, and NIMS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 288 hours
Time To Initiation - 288 hours
TRAJECTORY
As of noon (PDT) Thursday, September 5, 1991, the Galileo Spacecraft status
was as follows:
Distance from Earth 186,912,970 miles
Distance from Sun 192,113,130 miles (2.01 AU)
Heliocentric Speed 38,720 miles per hour
Distance from Gaspra 23,733,920 miles
Round Trip Light Time 33 minutes, 16 seconds
SPECIAL TOPICS
1. As of September 5, 1991, a total of 5778 real-time commands have been
transmitted to Galileo. Of these, 1913 have been pre-planned in the sequence
design and 3865 were not. In the past week, a total of 21 real time commands
were transmitted; two were pre-planned and 19 were unplanned. In addition 1903
mini-sequence commands have been transmitted since March 1991. Major
commanding activities this week included resetting the command loss timer,
transitioning to all-spin mode, performing an SSI memory readout, selecting the
low frequency subcarrier and sending the SSI cover "GO" command.
2. On September 3 and 4, while tracking over DSS-63, two unexpected CDS lock
counts were observed. This was the seventh and eighth occurrences of this event
which have been observed at stations DSS 14, 43, 61, and 63. In all instances,
there was no evidence of any spurious commands being received, processed, or
issued by the CDS. The CDS continues to receive, process, and issue all
planned commands properly.
About 9 months ago, a special team was formed to thoroughly investigate
these anomalous lock change events. After intensive review of the flight data
and all pertinent DSN (Deep Space Network) station configuration and procedural
information, the cause for most of these spurious lock changes is still
unknown. It is noted that the cause of one of eight events was identified and
found to be caused by a procedural error at the DSS-14 (70 meter Goldstone
station). Recent investigation efforts have now focused on the spacecraft
command hardware interface, particularly, the Command Detector Unit (CDU) and
the CDS. Preliminary computer simulations indicate the interface may be
sensitive to electrical noise which could cause spurious CDS lock changes if
noise characteristics are "just-right". Further investigation, including a
search for other possible spacecraft-related causes, is in process.
Review of the hardware development and test history indicates that no
unexpected lock changes were ever observed during the pre-launch test
activities. Additionally, interaction with Voyager operations personnel
revealed that they have had no unexpected lock changes during flight. The
Voyager and Galileo CDU-CDS command interfaces are nearly identical. In fact,
the CDU hardware is identical but operates at different command bit rates (16
bps for VGR, 32 bps for Galileo).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
Date: 7 Sep 91 01:02:15 GMT
From: (Ron Baalke)
Subject: Galileo Update #3 - 09/05/91
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
September 5, 1991
The Galileo spacecraft is about 187 million miles from Earth,
receding at roughly 1.5 million miles a day, going about 38,700 miles
per hour in its elliptical orbit around the Sun. Galileo has been
receding from Earth since December 1990 and from the Sun, independently,
since January 1991; in January 1992 it will begin to approach them again.
Round-trip communication time this week is 33.5 minutes.
The spacecraft is in a sequence-controlled cruise mode; it is in
all-spin, rotating at 2.89 rpm, until tomorrow. It is transmitting
engineering telemetry at 40 bits per second over its low-gain antenna.
All telemetry measurements are within expected ranges, indicating
good health. Today Galileo removed the transparent cover from its TV
imaging system optics. Friday, September 6, it begins optical
navigation activities, taking a picture of the sky to locate Gaspra in
the star background and help refine knowledge of the asteroid's position.
Gaspra is still almost 24 million miles away; the asteroid
encounter is just 8 weeks from today.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
Date: 6 Sep 91 20:45:24 GMT
From: (Ron Baalke)
Subject: Galileo Update - 09/06/91
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 6, 1991
The Galileo spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the imaging instrument (SSI) cover jettison activity was
completed. All telemetry data indicates that the SSI cover is removed.
Today, the spacecraft is scheduled to return to the dual-spin mode and
perform a 22-degree SITURN to Earth point; this action will significantly
improve the 40 bps telemetry link performance.
Also, today after a planned SSI MRO (Memory Readout), the first of four
planned optical navigation imaging activities will be performed in support of
Gaspra encounter. The imaging data will be collected and stored on the tape
recorder for subsequent play back at 40 bps via a DMSMRO (Data Management
Subsystem Memory Readout). This data return approach is similar to that used
for sending back early Venus images at 1200 bps.
Tomorrow, another SSI MRO is scheduled to verify the health and safety
of the instrument. No DSN (Deep Space Network) tracking coverage is scheduled
for Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.463 | Update - September 9 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Sep 10 1991 12:47 | 32 |
| Date: 9 Sep 91 23:28:37 GMT
From: (Ron Baalke)
Subject: Galileo Update - 09/09/91
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 9, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
On Saturday, September 7, the DMSMRO (Data Management Subsystem
Memory Readout) activity to return the optical navigation image was
initiated.
Today, another of the periodically planned RPM (Retro Propulsion
Module) 10-Newton thruster maintenance activity is scheduled.
Additionally, the command loss timer will be reset.
Tomorrow, continued DMSMRO of the optical navigation image is
scheduled and additional MROs are scheduled for the DDS (Dust
Detector), MAG (Magnetometer), and EUV (Extreme Ultraviolet
Spectrometer) instruments.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.464 | Update - September 10 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Sep 11 1991 12:26 | 30 |
| Date: 11 Sep 91 04:56:47 GMT
From: (Ron Baalke)
Subject: Galileo Update - 09/10/91
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 10, 1991
The Galileo spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 40 bps.
Yesterday, the spacecraft completed another 10-Newton thruster
"flushing" maintenance activity and continued the DMS (Data Management
Subsystem) MRO (Memory Readout) playback activity of the first
GASPRA-related optical navigation image.
Today, the DMS MRO playback activity will continue and MROs are
planned for the DDS (Dust Detector), MAG (Magnetometer) and EUV
(Extreme Ultraviolet) instruments.
Tomorrow, DMS MRO activity will continue.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.465 | Update - September 11 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Sep 12 1991 13:40 | 33 |
| Article 16742
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/11/91
Date: 12 Sep 91 01:30:50 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 11, 1991
The Galileo spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 40 bps.
Yesterday, the DMS (Data Management Subsystem) MRO (Memory Readout)
activity continued. The first segment, approximately 118 lines, of optical
navigation image #1 was delivered to the Image Processing Laboratory and
later to the Navigation Team. Data looks good.
Yesterday, science MROs of the DDS (Dust Detector), MAG (Magnetometer)
and EUV (Extreme Ultraviolet Spectrometer) instruments were completed.
Tomorrow, the DMS MRO of Optical Navigation Image #1 will continue.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Good judgement comes from
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | experience. Experience
|_____|/ |_|/ |_____|/ | comes from bad judgement.
|
| 560.466 | Update - September 12 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Sep 12 1991 19:17 | 40 |
| Article 16762
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/12/91
Date: 12 Sep 91 22:31:48 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
September 12, 1991
The Galileo spacecraft is almost 197 million miles from Earth,
and more than 194 million miles from the Sun. Its speed in orbit is
38,132 miles per hour.
The spacecraft is operating normally in the dual-spin mode,
rotating at 3.15 rpm. It is transmitting coded telemetry at 40 bits
per second; one-way communication time is currently 17 minutes 37 seconds.
On Tuesday the first segment of the first optical navigation
image, recorded September 6, was received, as were scientific data
from the dust detector, magnetometer, and extreme ultraviolet
instrument. Today the spacecraft is transmitting another segment of
the optical navigation image.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.467 | Update 2 - September 12 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Sep 13 1991 19:25 | 175 |
| Article 16812
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.astro
Subject: Galileo Update #2 - 09/12/91
Date: 13 Sep 91 23:46:58 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
September 6 - 12, 1991
SPACECRAFT
1. Under EE-2 (Earth-Earth 2) prime stored sequence control, the spacecraft
was commanded back to the dual-spin mode on September 6 in preparation for
performing a 22-degree SITURN toward Earth point to improve RF
(Radio Frequency) telemetry performance. After the turn the observed link
performance was about 4 db greater than at the start of the turn.
2. The first of four planned optical navigation observations in support of the
Gaspra encounter was completed on September 6. The data was collected and
stored on the tape recorder for playback over the next several weeks. Prior to
this imaging activity, an imaging instrument (SSI) memory readout was performed
to verify the instrument's health and performance. Another SSI MRO also was
performed on September 7.
3. A command was sent on September 9 to reset the command loss timer to 288
hours, its planned value for this mission phase.
4. Another of the periodically planned RPM (Retro Propulsion Module)10-Newton
thruster maintenance activities was performed on September 9. The S, L and Z
thrusters were "flushed"; the P-thrusters were not since they are used for
periodically HGA (High Gain Antenna) correct Earth pointing activities.
Spacecraft response throughout the activity was normal Thruster temperature
profiles were similar to those observed in previous operations.
5. Continued playback of the first optical navigation image occurred on
September 6, 9, 10, 11, and 12. Additionally, the MAG (Magnetometer), DDS
(Dust Detector) and EUV (Extreme Ultraviolet Spectrometer) instruments
completed memory readouts on September 10.
6. Two more unexpected CDS (Command Data Subsystem) lock change indication
events was observed over DSS-63 (Madrid 70 meter station) on September 5 and 6.
Similar to past events there was no indication that the spacecraft received,
processed or issued a command. In support of the CDS lock change anomaly
effort, a special uplink command test was conducted on September 8 using
DSS-63. The test involved transmitting an uplink RF carrier at three
transmitter power levels to determine if lock changes are sensitive to RF
power; no lock changes were observed.
7. The AC/DC bus imbalance measurements exhibited some changes. The AC
measurement fluctuated 3 DN and now reads 45.3 volts; the DC measurement
decreased 5 DN and now reads 15.3 volts. All other power telemetry and
subsystem telemetry are normal.
8. The Spacecraft status as of end of day September 12 was as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Earth pointed; Sun Point Angle
- approximately 28 degrees (sun lagging) plus or
minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS,
PPR and NIMS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 288 hours
Time To Initiation - 192 hours
GDS (Ground Data Systems):
1. During playback of initial segment the first Optical Navigation (OPNAV 1)
picture, an MTS problem was discovered which caused 8 out of the first 136
lines of the picture to be dropped in the data processed in real time. This
was no impact to OPNAV 1 since the data were fully recovered by off-line MTS
replay. But since timelines for the TCM (Trajectory Correction Maneuver) tweak
(OPNAV 4) and pointing tweak (OPNAV 5) are more demanding, a decision was made
to fix the problem. Wednesday, the Project Change Board (PCB) approved patches
developed and tested by the Flight Control and Support Office (FCSO) to be
placed on the backup MTS Thursday and both systems (prime and backup) on Friday.
2. The German Space Operations Center (GSOC) has completed testing of a new
version of their telemetry System (Version 7.6) which corrects 9 "Non
Conformance Reports" (NCRs) discovered in earlier testing. Version 7.6 of the
telemetry system will be used to support cruise science operations at GSOC
after deployment of the High Gain Antenna.
3. In order to provide backup for GDS single point failures during processing
of OPNAV 4 and OPNAV 5 data, the Project has endorsed a plan by the
Multimission Image Processing Lab (MIPL) to port a software Reed-Solomon
Decoder developed by SFOC to the MIPL VAX.
4. GDS tests of the DSN (Deep Space Network) Telemetry Processing Assemblies
(TPA) at Madrid were conducted to characterize the ERT (Earth Receive Time)
time-tagging differences between "Type A" and "Type B" telemetry strings. A
consistent 11-14 millisecond difference was observed. Further tests are
planned with Goldstone and Canberra to fully characterize the differences prior
to possible Galileo prime support with Type B telemetry strings. These
differences need to be characterized and understood for accurate determination
of spacecraft clock drift and correlation with UTC time.
5. The September System Engineers Monthly Report (SEMR) review was conducted
Thursday, August 12th. A review of current Project and institutional (FPSO &
DSN) system status was conducted. Gaspra readiness, delivery schedules,
accomplishments and potential problem areas were discussed. Several
post-Gaspra software delivery schedule concerns and potential problem areas
were identified and are documented in the summary report memo. No Gaspra
related problems were identified.
TRAJECTORY
As of noon Thursday, September 12, 1991, the Galileo Spacecraft status was as
follows:
Distance from Earth 196,598,950 miles
Distance from Sun 194,145,070 miles (2.03 AU)
Heliocentric Speed 38,130 miles per hour
Distance from Gaspra 20,568,090 miles
Round Trip Light Time 35 minutes, 0 seconds
SPECIAL TOPICS
1. As of September 12, 1991, a total of 5785 real-time commands have been
transmitted to Galileo. Of these, 1914 have been pre-planned in the sequence
design and 3871 were not. In the past week, only one real time command was
transmitted; and one was pre-planned. In addition 1903 mini-sequence commands
have been transmitted since March 1991. Major commanding activities this week
included resetting the command loss timer.
2. On September 5 and 6, while tracking over DSS-63, two unexpected CDS lock
counts were observed. This was the ninth and tenth occurrences of this event
which have been observed at stations DSS 14, 43, 61, and 63. In all instances,
there was no evidence of any spurious commands being received, processed, or
issued by the CDS. The CDS continues to receive, process, and issue all
planned commands properly.
About 9 months ago, a special team was formed to thoroughly investigate
these anomalous lock change events. After intensive review of the flight data
and all pertinent DSN station configuration and procedural information, the
cause for most of these spurious lock changes is still unknown. It is noted
that the cause of one of eight events was identified and found to be caused by
a procedural error at the DSS-14 (Goldstone 70 meter station). Recent
investigation efforts have now focused on the spacecraft command hardware
interface, particularly, the Command Detector Unit (CDU) and the CDS.
Preliminary computer simulations indicate the interface may be sensitive to
electrical noise which could cause a spurious CDS lock change if noise
characteristics are "just-right".
Although, noise may be able to cause a lock change indication, it is
thought unlikely because the observed anomalies have:
(a) always occurred in pairs (in-lock, out-of-lock) and
(b) always been observed in both halves of the CDS
This signature implies that a spurious signal maybe present on the lock
indication interface between the CDU and the CDS. Further investigation,
including a search for other possible causes, is in process.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.468 | Update - September 13 | MTWAIN::KLAES | All the Universe, or nothing! | Sat Sep 14 1991 15:13 | 30 |
| Article 16823
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/13/91
Date: 13 Sep 91 23:32:23 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 13, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Today, the continued playback of the first of four planned optical
navigation images was performed via the tape recorder memory readout (DMS MRO).
Approximately 35% of the image has been received.
Over the weekend, the DMS MRO will continue; no other spacecraft
activities are planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.469 | Update - September 16 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Sep 17 1991 16:57 | 33 |
| Article 16910
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/16/91
Date: 17 Sep 91 04:11:48 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 16, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Today, the tape recorder playback activity (DMS MRO) is scheduled
to continue. This activity is sending back the GASPRA optical
navigation image taken on September 6; about 44 percent of the image
will be returned by end of day today.
In addition to the image playback, a USO ultra stable oscillator
frequency test will be performed.
Tomorrow, no spacecraft activities are scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.470 | Update - September 17 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Sep 18 1991 20:09 | 31 |
| Article 16938
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/17/91
Date: 17 Sep 91 23:29:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 17, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Today, no spacecraft activity is planned.
Tomorrow, continued playback of the GASPRA optical navigation
image is scheduled. Additionally, an imaging instrument (SSI) memory
readout is planned to verify the instrument's health and safety. An
EPD (Energetic Particles Detector) motor maintenance activity is also
planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.471 | Update - September 18 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Sep 19 1991 12:09 | 34 |
| Article 16967
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/18/91
Date: 19 Sep 91 04:45:19 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 18, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Playback of the Gaspra optical image data continues today. At the end of
the DSS-63 (Madrid 70 meter station) pass today approximately 410 lines of
optical navigation image No. 1 will have been received on the ground.
The routine periodic EPD (Energetic Particles Detector) motor maintenance
activities occurred today as planned. An imaging instrument (SSI) memory
readout occurred today as planned to verify the instrument's health and safety.
Tomorrow no spacecraft activity is scheduled; no tracking coverage is
scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.472 | Update - September 19 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Sep 20 1991 14:40 | 72 |
| Article 17005
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/19/91
Date: 19 Sep 91 22:12:47 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
September 19, 1991
The Galileo spacecraft is more than 206 million miles from Earth,
and about 196 million miles from the Sun. It has traveled 1.055
billion miles in its looping flight path since launch in October 1989,
and has about 35 million miles more to go before encountering Gaspra
on October 29, 1991.
On Monday, Wednesday, and Friday this week the spacecraft was
scheduled to play back recorded segments of its first optical
navigation image, which will locate Gaspra among background stars and
help the flight team correct Galileo's flight path and aim instruments
for the encounter. More than half of that image had been received as
of Wednesday.
The spacecraft is operating normally in the dual-spin mode, with
the spin axis pointed toward Earth, transmitting coded telemetry at 40
bits per second. Tuesday and today no tracking or other spacecraft
activity was scheduled.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
Article 17016
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 09/19/91
Date: 20 Sep 91 03:33:11 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 19, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
No spacecraft activities were planned for today.
A special wobble identification activity will be commanded tomorrow to
gather data defining the x and y axis components of the spacecraft wobble.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.473 | Update - September 20 | MTWAIN::KLAES | All the Universe, or nothing! | Sun Sep 22 1991 18:14 | 164 |
| Article 17032
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/20/91
Date: 20 Sep 91 21:20:09 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
September 13 - 19, 1991
SPACECRAFT
1. The tape recorder (DMS) playback of the Gaspra optical navigation image
continued this week with DMS memory readout activities completed on
September 15, 16 and 18. Approximately 55 percent of the image has now been
returned.
2. Two imaging instrument (SSI) memory readouts were completed on September 14
and 18 to verify the instrument's health and safety.
3. A NO-OP command was sent on September 18 to reset the command loss timer to
288 hours, its planned value for this mission phase.
4. An Ultra-Stable Oscillator (USO) test was performed on September 18 to
characterize this ultra stable RF downlink frequency source.
5. The energetic particle instrument (EPD) performed a sector scan on
September 18 as part of its regularly scheduled motor maintenance activity.
After the scan the motor was repositioned back to Sector 4. Proper motor
positioning was verified via EPD MRO (Memory Readout) data.
6. The AC/DC bus imbalance measurements exhibited some changes. The AC
measurement fluctuated 12 DN and now reads 43.7 volts; the DC measurement
changed 12 DN and now reads 14.4 volts. All other power telemetry and
subsystem telemetry are normal.
7. Commands were sent on September 18 and 19 to precondition the spacecraft
for a special Wobble Identification activity planned for September 20.
8. The Spacecraft status as of end of day September 19 was as follows:
a) System Power Margin - 71.5 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Earth pointed; Sun Point Angle
- approximately 27 degrees (sun lagging) plus or
minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR and
NIMS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 288 hours
Time To Initiation - 284 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL: None
Project reviewed and approved the EE-3 (Earth-Earth 3)prime Gaspra
encounter profile design on September 17.
GDS (Ground Data Systems):
1. The first combination DSN (Deep Space Network) Mission Readiness Test (MRT)
and Project Ground Data System (GDS) test was successfully completed on
September 15th with DSS-43 (Canberra 70 meter station). The objective of the
tests are to demonstrate DSN and GDS readiness for Gaspra support. The Project
and DSN tests are being combined to minimize requirements for DSN resources.
Project GDS testing has indicated inconsistent time tagging of telemetry data
during DSN Type B Telemetry Processor Assembly (TPA) string support. Although
this will not affect Gaspra support, this needs to be understood and resolved
before standard operational support can begin using the Type B string.
Operational support is currently scheduled on Type A strings which do not have
this problem. However, the Project is interested in switching as soon as
possible to take advantage of the better performance available with Type B
telemetry.
TRAJECTORY
As of noon Thursday, September 19, 1991, the Galileo Spacecraft status was
as follows:
Distance from Earth 206,104,380 miles
Distance from Sun 196,059,380 miles (2.11 AU)
Heliocentric Speed 37,580 miles per hour
Distance from Gaspra 17,449,040 miles
Round Trip Light Time 36 minutes, 44 seconds
SPECIAL TOPICS
1. As of September 19, 1991, a total of 5790 real-time commands have been
transmitted to Galileo. Of these, 1915 have been pre-planned in the sequence
design and 3875 were not. In the past week, five real time commands were
transmitted; of these one was pre-planned. In addition 1903 mini-sequence
commands have been transmitted since March 1991. Major commanding activities
this week included resetting the command loss time, Wobble ID related DAC
(Delayed Action Commands) turning the TWNC on and the gyro heaters on before
the Wobble ID and gyros off following the Wobble ID.
2. On September 13, the spacecraft WOBEST attitude control telemetry
measurement indicated an unexpected change of about 1 mrad. The cause for this
change is unknown but may be due to a slight change in position of the
magnetometer boom induced by the last week's SITURN to Earth point and/or
thermal deflection induced by solar input at Earth pointed attitude (30-degrees
off sun attitude). The wobble data continued to change over the week
decreasing to approximately .1 mrad (a value very close to the wobble achieved
after the pre EE-2 wobble compensation activity on August 24). A spacecraft
full (x and y axis) wobble identification test is being planned for
September 20. The consequences of the wobble change on the optical navigation
and Gaspra activities is being assessed.
3. A training exercise of the uplink process which will be required to
generate "tweaks" to the Scan Platform pointing for Gaspra was conducted in a
series of non-real time segments from September 10th through September 12th.
Although the tweak process completed about 6 hours late, a post-test critique
concluded that most of the problems were related to the preliminary nature of
the baseline sequence. A test report memo was distributed documenting findings
and resulting actions. A retest will be conducted during the week of September
30th.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
Article 17033
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 09/20/91
Date: 20 Sep 91 22:49:03 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 20, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
A special wobble identification activity is being commanded today to
gather telemetry data defining the x and y axis components of the spacecraft
wobble.
No spacecraft activities are planned over the weekend; no tracking
coverage is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.474 | No Mention of THE Most Critical Item | FASDER::ASCOLARO | Not Short, Vertically Challenged | Mon Sep 23 1991 12:07 | 7 |
| I'm sorry, but I think JPL has gone into denigal on this one.
The 'Mission Director Status Report' and there is no mention whatsoever
of the stuck main antenna. I think it deserves at least one line about
plans or something.
Tony
|
| 560.475 | re -1 | TUCKER::BIRO | | Tue Sep 24 1991 10:33 | 9 |
| Yes, their seem to be two questions,
1) what is the stauts of the images being sent back, yes I know that it
is just a partial but is it data or noise
2) the change in the wobble, any speculation that the stucked ant
has moved... I agree they seem to be soft-footing the issues
jb
|
| 560.476 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Tue Sep 24 1991 12:08 | 17 |
| re -.1
re: the wobble.
I did not get that the wobble had changed, only that they were trying
to eliminate it, by rebalancing the spacecraft, so the camera would
point straight for the encounter.
re: the status of the images
I thought that was with regard to the up-down link, not anything to do
with the undeployed antenna.
Sure is some awful cryptic was to talk about the problem and NO
discussion of any effort to eliminate the problem!
Tony
|
| 560.477 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Tue Sep 24 1991 16:03 | 21 |
| From .473:
>2. On September 13, the spacecraft WOBEST attitude control telemetry
>measurement indicated an unexpected change of about 1 mrad. The cause for this
>change is unknown but may be due to a slight change in position of the
>magnetometer boom induced by the last week's SITURN to Earth point and/or
>thermal deflection induced by solar input at Earth pointed attitude (30-degrees
>off sun attitude). The wobble data continued to change over the week
>decreasing to approximately .1 mrad (a value very close to the wobble achieved
>after the pre EE-2 wobble compensation activity on August 24). A spacecraft
>full (x and y axis) wobble identification test is being planned for
>September 20. The consequences of the wobble change on the optical navigation
>and Gaspra activities is being assessed.
There was a change in the wobble. For whatever reason, though, they seem to
think that it was related to the magnetometer, not the HGA. (I guess the
HGA is either on-axis or else in the despun part, though, so maybe it does
would not affect the wobble???)
Burns
|
| 560.478 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Tue Sep 24 1991 17:01 | 9 |
| re .477
Stupid me. I read the section you quoted and accepted the wobble was
from the magnetometer and completely put it out of my mind as being not
related to the hga problem.
I would still like to hear more about hga plans tho .....
Tony
|
| 560.479 | Update - September 23 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Sep 24 1991 20:05 | 34 |
| Article 17098
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/23/91
Date: 24 Sep 91 05:25:28 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 23, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
No spacecraft activities were planned over the weekend; no tracking
coverage was scheduled.
Today playback of Optical Navigation Image Number 1 continues. In
additional 100 lines of the image will be returned today over DSS 63
Madrid and DSS14 Goldstone. In addition a SSI (Solid State Imaging) health
check memory readout will be performed.
Tomorrow playback of the optical navigation data will continue. There
will also be a MAG (Magnetometer) instrument science data memory readout.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.480 | Updates - September 24-27 | MTWAIN::KLAES | All the Universe, or nothing! | Sun Sep 29 1991 16:15 | 168 |
| Article 17116
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/24/91
Date: 24 Sep 91 23:33:50 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 24, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Playback of Optical Navigation Image No. 1 continues today. By the end
of the Canberra Pass later tonight, more than 75% of the total image will have
been captured on the ground and delivered to the Image processing system.
Tomorrow, the Playback of Optical Navigation Image No.1 will continue. A
periodic RPM (Retro Propulsion Module) flushing active is also planned. In
addition, there will also be MAG (Magnetometer) and EUV (Extreme Ultraviolet
Spectrometer) instrument science data memory readouts.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
Article 17141
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/25/91
Date: 26 Sep 91 00:40:27 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 25, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Playback of Optical Navigation Image No. 1 continues today. By the end of
the Goldstone Pass later tonight, more than 90% of the total image will have
been captured on the ground. Unless there is some major problem in the next
three scheduled tracking passes it will not be necessary to use the Contingency
Playback Window. Retrieval of Optical Navigation Image No. 1 went very well.
A periodic RPM (Retro Propulsion Module) flushing activity is
scheduled for today.
Tomorrow, no spacecraft activities are planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
Article 17146
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 09/25/91
Date: 26 Sep 91 06:06:27 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
September 25, 1991
The Galileo spacecraft is 214 million miles from Earth, and 197.6
million miles from the Sun; it is receding from both. Its speed in
orbit is 37,143 miles per hour. The spacecraft still has to fly about
29 million miles along the orbit before its encounter with Gaspra in
just under five weeks.
Galileo is operating normally in dual spin, transmitting coded
telemetry at 40 bits per second. By the end of today, it will have
transmitted more than 90 percent of the first optical navigation
image. The image already indicates Gaspra's position against
background stars, fully meeting the navigation data requirements.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
Article 17154
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/26/91
Date: 26 Sep 91 21:58:55 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 26, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Playback of Optical Navigation Image No. 1 continues today. By the end of
the Goldstone pass later tonight the total image will have been captured on the
ground. The Contingency Playback Window will not be used. Retrieval of
Optical Navigation Image No. 1 went very well.
Optical Navigation Image No.2 will be shuttered tomorrow. The DMS (Data
Management Subsystem) will be set up for the DMSMRO (DMS Memory Readout)
playback of that image.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
Article 17177
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/27/91
Date: 27 Sep 91 20:53:45 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 27, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Today, the second of the four planned optical navigation images will be
shuttered this evening and stored on the tape recorder for playback over the
next 2 weeks; playback of the image will begin tomorrow.
Also tomorrow, an imaging instrument (SSI) memory readout will be
performed to verify the instrument's health status.
No spacecraft activity is planned on Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.481 | GALILEO gives further evidence for Venus lightning | MTWAIN::KLAES | All the Universe, or nothing! | Sun Sep 29 1991 16:17 | 52 |
| Article 17164
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Detects Lightning on Venus
Date: 27 Sep 91 02:29:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Paula Cleggett
Headquarters, Washington, D.C. September 26, 1991
(Phone: 202/453-1549)
James H. Wilson
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
RELEASE: 91-156
LIGHTNING STORMS DETECTED IN VENUS ATMOSPHERE
Scientists who studied the planet Venus from data received
from the interplanetary spacecraft Galileo have greatly increased
confidence that there are lightning storms in that planet's atmosphere.
The science team used the spacecraft's plasma wave instrument
to detect electromagnetic equivalents of thunderclaps most probably
generated by lightning bolts deep in the atmosphere.
Galileo flew by Venus at a distance of about 10,000 miles in
February 1990. Pictures and other observations of the planet were
recorded and then transmitted to Earth in November 1990, according to
plan. Scientists have been analyzing the data since then.
Galileo's primary scientific objective is to conduct close
and extended observations of Jupiter, its atmosphere and its moons,
beginning in December 1995. Launched in 1989, it was programmed to
fly by Venus and Earth for gravity assists to help it reach Jupiter.
It flew by Earth in December 1990 and is currently in the Asteroid
Belt where it will obtain a close look at the asteroid Gaspra this
October before returning for a second and final Earth flyby in
December 1992.
Science magazine published this week a collection of eight
scientific articles on Galileo's Venus observations.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Beware of programmers who
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | carry solder irons.
|_____|/ |_|/ |_____|/ |
|
| 560.482 | Update - September 27 (#2) | MTWAIN::KLAES | All the Universe, or nothing! | Sun Sep 29 1991 18:23 | 135 |
| Article 17185
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 09/27/91
Date: 27 Sep 91 23:48:06 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
September 20 - 26, 1991
SPACECRAFT
1. The tape recorder (DMS) playback of the Gaspra optical navigation image
continued this week with DMS memory readout activities on September 23, 24, 25
and 26. Full retrieval of the first of the four planned optical navigation
images is going very well; full return is expected by September 27; therefore
the planned contingency playback window will not be needed. The next optical
navigation image will be shuttered on September 27 and stored on the DMS for
playback over the next two plus weeks.
2. A special spacecraft wobble identification activity was commanded on
September 20. The wobble information was collected from gyro data in both the
X and Y axes. This activity was performed in response to the unexpected Y-axis
wobble change (approximately 1 mrad) observed in the WOBEST measurement on
September 13; no change was detected in the X-axis from the previous wobble.
The cause for the unexpected Y-axis change is being investigated.
3. Another imaging subsystem (SSI) memory readout was performed on
September 23 to verify the imaging instrument's health status.
4. A NO-OP command was sent of September 23 to reset the command loss timer to
288 hours, its planned value for this mission phase.
5. A cruise science memory readout for the MAG (Magnetometer) and EUV (Extreme
Ultraviolet Spectrometer) instruments was completed on September 24.
6. An RPM (Retro Propulsion Module) thruster maintenance "flushing" activity
was completed on September 25. Only 10 of 12 thrusters were "flushed" during
this exercise; the P-thrusters were not "flushed" since they are used
periodically to perform Earth point activities.
7. Several (12) Delayed Action Commands (DACs) were sent on September 24; all
were attitude control pointing deadband commands to increase the pointing
deadband to 100 mrad to preclude a possible command constraint violation if an
autonomous HGA (High Gain Antenna) correction activity were to take place at
the same time the thruster PA issued a scan platform safe command.
8. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement dropped about 8 DN and now reads near 43.7 volts; the DC
measurement dropped 2 Dn and now read 15.1 volts. All other power telemetry
and subsystem telemetry are normal.
9. The Spacecraft status as of end of day September 26 was as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Earth pointed; Sun Point Angle
- approximately 26.4 degrees (sun lagging) plus or
minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR and
NIMS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 288 hours
Time To Initiation - 240 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL: None
GDS (Ground Data Systems):
1. Unit testing has been successfully completed on the Multimission Image
Processing Lab (MIPL) software Reed Solomon decoder. The software decoder will
provide a backup to the hardware decoder used to process optical navigation
pictures for Gaspra. Data from OPNAV 1 passed through both the hardware and
software decoders during unit testing yielded identical outputs. System
and integration testing has now started with delivery scheduled for October 9th.
Agreement was reached with the Voyager Project for the use of their decoder
interface card during critical periods in the event the software decoder
implementation does not work.
2. The DSN (Deep Space Network) successfully completed the Gaspra Mission
Readiness Test (MRT) with DSS-63 (Madrid 70 meter station) on September 23rd.
Project test personnel are continuing to work with the DSN to eliminate
telemetry time tagging variations on the Type B telemetry strings when used for
Galileo support. Although this will not affect Gaspra support, the variations
need to be eliminated to permit the Project to periodically calibrate the drift
in the spacecraft clock.
TRAJECTORY
As of noon Thursday, September 26, 1991, the Galileo Spacecraft status was as
follows:
Distance from Earth 215,385,600 miles
Distance from Sun 187,856,500 miles (2.12 AU)
Heliocentric Speed 37,070 miles per hour
Distance from Gaspra 14,367,680 miles
Round Trip Light Time 38 minutes, 22 seconds
SPECIAL TOPICS
1. As of September 26, 1991, a total of 5828 real-time commands have been
transmitted to Galileo. Of these, 1916 have been pre-planned in the sequence
design and 3912 were not. In the past week, 38 real time commands were
transmitted; of these one was pre-planned. In addition 1903 mini-sequence
commands have been transmitted since March 1991. Major commanding activities
this week included resetting the command loss timer, widening the pointing
deadband and reconfiguring the radio subsystem to collect ranging navigation
data.
2. At beginning of the DSS-63 pass on September 23, two unexpected CDS
(Command Data Subsystem) lock changes were observed. This is the 11th
occurrence of this event. The spacecraft telemetry signature was identical to
the previous 10 events. As on previous occasions, there was no evidence that a
command was received or issued by the CDS; all planned commands were properly
processed by the CDS.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.483 | Update - September 30 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Sep 30 1991 20:43 | 30 |
| Article 17237
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 09/30/91
Date: 30 Sep 91 23:04:00 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 30, 199
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
The second of the four planned optical navigation images is
currently being playedback from the spacecraft's tape recorder; about
10% of the image has been returned.
Today and tomorrow, spacecraft activities will include continued
playback of the optical navigation image.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.484 | | DECWIN::FISHER | Klingons don't "enter a relationship"...they conquer | Tue Oct 01 1991 14:23 | 14 |
|
>7. Several (12) Delayed Action Commands (DACs) were sent on September 24; all
>were attitude control pointing deadband commands to increase the pointing
>deadband to 100 mrad to preclude a possible command constraint violation if an
>autonomous HGA (High Gain Antenna) correction activity were to take place at
>the same time the thruster PA issued a scan platform safe command.
Can anyone translate this? I suppose an "autonomous HGA correction activity"
means "the HGA pops out by itself for some unknown reason", but what is a
"thruster PA", and why might it issue a scan platform safe command (and what
is that?)
Burns
|
| 560.485 | Update - October 1 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Oct 02 1991 12:49 | 25 |
| Date: 2 Oct 91 00:46:24 GMT
From: (Ron Baalke)
Subject: Galileo Update - 10/01/91
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 1, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Today, playback of the second of the planned four optical navigation
images will be continued.
Tomorrow, the image playback activity will continue and a USO (Ultra
Stable Oscillator) test will be performed.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.486 | Update - October 2 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Oct 03 1991 13:28 | 48 |
| Article: 17276
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/02/91
Date: 3 Oct 91 02:41:17 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
October 2, 1991
The Galileo spacecraft is more than 223 million miles from Earth,
making the round-trip communication time about 40 minutes. It is more
than 199 million miles from the Sun, and 11.75 million miles (straight
line) from Gaspra. Speed in orbit is 36,662 miles per hour.
The spacecraft is operating normally in the dual-spin mode, with
the spinning section rotating at 3.15 rpm and the spin axis pointed
toward Earth, approximately 25 degrees away from the Sun. It is
transmitting coded telemetry at 40 bits per second over the low-gain
antenna.
Galileo's second optical navigation image, shuttered Friday
night, is being played back through an onboard computer memory in
installments. By the end of today's playback, about 20% of this image
should have been received through the Deep Space Network by the
navigation team.
The flight team members are preparing for and testing various
special activities needed in the Gaspra encounter, and are also
preparing Galileo's next trajectory correction maneuver, planned for
October 9, a week from today.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.487 | Update - October 3 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Oct 04 1991 14:27 | 138 |
| Date: 3 Oct 91 23:08:30 GMT
From: (Ron Baalke)
Subject: Galileo Update - 10/03/91
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 3, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Today, continued playback of the second optical navigation image
will be performed.
Tomorrow, continued playback of the image is planned. Also, an
imaging instrument (SSI) memory readout is scheduled to verify the
health status of the SSI.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
Date: 4 Oct 91 02:10:11 GMT
From: (Ron Baalke)
Subject: Galileo Update #2 - 10/03/91
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
September 27 - October 3, 1991
SPACECRAFT
1. The second of the planned four optical navigation images in support of the
Gaspra encounter was taken on September 28. The image was stored on the
spacecraft's tape recorder (DMS) for playback over the next two plus weeks.
2. Playback of the second optical navigation image was performed on
September 28, 30 and October 1, 2 and 3 via the DMS MRO (Memory Readout)
activity. Playback is proceeding well with more than 40 percent of the image
retrieved; full image retrieval is expected by October 12.
3. Two imaging subsystem (SSI) memory readouts were performed on September 28
and 30. The memory readouts are done routinely to verify the health status of
the SSI.
4. A NO-OP command was sent of September 30 to reset the command loss timer to
288 hours, its planned value for this mission phase.
5. A command was sent on October 1 to readout the CDS (Command Data Subsystem)
attitude control alert-code buffer to determine when autonomous HGA (High Gain
Antenna) pointing corrections occur.
6. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement increased 3 DN and now reads near 45.03 volts; the DC measurement
dropped 8 DN and now reads near 14.6 volts. All other power telemetry and
subsystem telemetry are normal.
7. The Spacecraft status as of end of day October 3 was as follows:
a) System Power Margin - 66 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Earth pointed; Sun Point Angle
- approximately 25 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR and NIMS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 288 hours
Time To Initiation - 210 hours
GDS (Ground Data Systems):
1. The DSN (Deep Space Network) reports that all Mission Readiness Tests
(MRTs) for the Gaspra encounter have been successfully completed. Project
Ground Data (GDS) tests were conducted in conjunction with the MRTs to
demonstrate end-to-end data system capabilities.
2. The DSN reports that the ability to recover telemetry from open loop
recordings of the Galileo downlink by the DSCC Spectrum Processor (DSP) was
verified by analysis of recordings by the Radio Science Team. This will be
used as a backup during Gaspra closest approach to ensure collection of
engineering telemetry.
TRAJECTORY
As of noon Thursday, October 3, 1991, the Galileo Spacecraft status was
as follows:
Distance from Earth 224,406,590 miles
Distance from Sun 199,536,900 miles (2.14 AU)
Heliocentric Speed 36,595 miles per hour
Distance from Gaspra 11,315,660 miles
Round Trip Light Time 40 minutes, 0 seconds
SPECIAL TOPICS
1. As of October 3, 1991, a total of 5832 real-time commands have been
transmitted to Galileo. Of these, 1917 have been pre-planned in the sequence
design and 3915 were not. In the past week, 4 real time commands were
transmitted; of these one was pre-planned. In addition 1903 mini-sequence
commands have been transmitted since March 1991. Major commanding activities
this week included resetting the command loss timer, and reading out the CDS
attitude control alert code buffer.
2. The TCM-11 (Trajectory Correction Maneuver 11) design was approved by the
Project on October 2. This maneuver consists of two burn segments, i.e., a
single positive Z and a single lateral burn. The P1A thruster and L thrusters
will be used. The total FV expected is about 0.35 m/sec. The maneuver is
scheduled for October 9.
3. The second training exercise of the uplink process which will be required
to generate "tweaks" to the scan platform pointing for Gaspra was completed
this week. The test successfully demonstrated the ability to generate DAC
(Delayed Action Commands) and sequence tweak updates per the required worst
case timelines for Gaspra. A test report memo will be distributed documenting
detailed findings and resulting actions.
4. The German Space Operations Center (GSOC) reports the Galileo GSOC
Operations Plan has been signed. The Operations Plan which is part of the
Galileo Space Flight Operations Plan (SFOP) details the GSOC Operations Team
organization and approach to support of the Galileo Cruise Science mission
phase. GSOC cruise science support will begin as early as late May 1992
pending deploy of the High Gain Antenna (HGA).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.488 | Updates - October 4-7 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Oct 07 1991 22:17 | 72 |
| Article: 17302
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/04/91
Date: 5 Oct 91 03:19:03 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 4, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Today, playback of the second optical navigtion image will continue.
Also, an imaging instrument (SSI) memory readout will be performed to verify
the health status of the SSI.
Saturday, the image playback activity will continue .
Sunday, no spacecraft activities are scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
Article: 17349
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/07/91
Date: 7 Oct 91 20:59:59 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 7, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Today, playback of the second optical navigation image will continue
(about 75% of the image will be retrieved). Additionally, cruise science
memory readouts for the EUV (Extreme Ultraviolet Spectrometer), MAG
(Magnetometer) and dust (DDS) instruments are scheduled; also, an imaging
instrument (SSI) memory readout to verify the health of the SSI is planned.
The EPD (Energetic Particles Detector) motor will be stepped from position
4 to position 0 in preparation for the TCM-11 (Trajectory Correction Maneuver
11) scheduled for October 9. The TCM-11 maneuver memory load is scheduled for
transmission to Galileo this afternoon (PDT). The maneuver is planned to
impart a delta velocity of about 0.35 m/sec.
Finally, a command to reset the command loss timer will be sent.
Tomorrow, commands will be sent to select the 10 bps data rate and the
low frequency subcarrier (22 kHz). Also, the playback of the second optical
navigation image will continue.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.489 | Update - October 8 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Oct 09 1991 13:35 | 37 |
| Article: 17369
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/08/91
Date: 8 Oct 91 23:18:33 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 8, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
All of the spacecraft activities planned for Monday were
completed without incident including the continued playback of the
optical navigation image; about 92% of the second optical navigation
image has been retrieved.
Early today, an attitude control wobble identification activity
was performed to collect data for the scheduled wobble compensation on
Thursday. Also today, the 10 bps telemetry rate and the low frequency
subcarrier will be selected.
Tomorrow, the TCM-11 (Trajectory Correction Maneuver 11) is
scheduled to be performed. The first burn pulse is planned to occur
at about 1000 PDT.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.490 | Updates - October 8-9 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Oct 10 1991 16:09 | 81 |
| Article: 17391
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 10/08/91
Date: 9 Oct 91 21:07:54 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
October 8, 1991
The Galileo spacecraft is almost 231 million miles from Earth,
and nearly 201 million miles from the Sun. Speed in orbit is 36,276
miles per hour.
The spacecraft is operating normally in the dual-spin mode,
transmitting coded telemetry at 40 bits per second. This includes
playback of portions of the second optical navigation image (totaling
nearly 90 percent of the image through yesterday) as well as
engineering measurements and some cruise science.
Yesterday afternoon the project team sent Galileo the maneuver
sequence for Wednesday's trajectory correction maneuver. Today the
data rate will be changed to 10 bits per second for the maneuver.
Tomorrow mid-morning (PDT) the spacecraft will pulse its Z-axis
(downward) and lateral thrusters to change its velocity by 0.35 meters
per second, less than one mile per hour, and target itself for the
October 29 flyby of the asteroid Gaspra at a closest approach of about
1,000 miles.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
Article: 17397
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/09/91
Date: 9 Oct 91 23:28:37 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 9, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps.
Today, Galileo will perform TCM-11 (Trajectory Correction
Maneuver 11) to impart a delta velocity of about 0.35 m/sec. The
first thruster burn pulse is scheduled to occur at about 1000 (PDT).
Tomorrow, the 40 bps telemetry data rate will be reselected
consistent with RF link performance predictions. Also, the DMS (Data
Management Subsystem) memory readout activity will continue to
retrieve the second optical navigation image (about 92% has been
retrieved), an imaging instrument (SSI) memory readout will be
performed to verify its health status, and the EPD (Energetic
Particles Detector) will be returned to Sector 4.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.491 | Update - October 10 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Oct 11 1991 14:03 | 35 |
| Article: 17417
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/10/91
Date: 11 Oct 91 02:01:37 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 10, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the TCM-11 (Trajectory Correction Maneuver 11) was performed.
Preliminary indications that the spacecraft performance was normal.
Today, commands will be sent to reselect the 40 bps data rate consistent
with RF link performance predictions; readout of the optical navigation No. 3
image will continue; an image instrument (SSI) memory readout will be
performed; and the EPD (Energetic Particles Detector) will be stepped back to
portion 4.
Tomorrow, readout of the final lines of the No. 3 optical navigation image
will occur.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.492 | Update - October 11 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Oct 11 1991 18:49 | 181 |
| Article: 17436
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/11/91
Date: 11 Oct 91 22:41:57 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
October 4 - 10, 1991
SPACECRAFT
1. Playback of the second of the four optical navigation images was performed
on October 4, 5, 7, 8, and 10. The playback activity is proceeding well with
95 percent of the image retrieved. The third optical navigation image is
scheduled to be shuttered on October 13.
2. A NO-OP command was sent on October 7 to reset the command loss timer to
288 hours, its planned value for this mission phase.
3. A cruise science memory readout was performed for the EUV (Extreme
Ultraviolet Spectrometer), DDS (Dust Detector) and MAG (Magnetometer)
instruments on October 7. Additionally, imaging instrument (SSI) memory
readouts were completed on October 7 and 10 to verify the health status of
the SSI.
4. A set of commands was sent on October 10 to retrieve a selected and limited
amount (about 1 RIM) of UVS (Ultraviolet Spectrometer) Lyman-Alpha data
collected and stored on the tape recorder (DMS) in February 1991. This data
will be retrieved from Track 1 using a DMSMRO (DMS Memory Readout) activity
planned to begin on October 11. The DMSMRO will be performed during the
optical navigation image contingency playback window.
5. Commands were sent on October 8 to perform a wobble identification activity
to determine if a wobble compensation is needed prior to taking the third
optical navigation image on October 13. The wobble activity collected
gyro-based wobble data in both the X- and Y-axes; the total wobble was about
0.6 mrad. From these data, it was determined that no wobble compensation is
needed.
6. Commands were sent on October 8 to reduce the telemetry data rate from 40
bps to 10 bps and to select the low frequency subcarrier (22.5 khz). These
actions were taken to improve the telemetry link performance and guarantee
"solid" telemetry before and during TCM-11 (Trajectory Correction Maneuver 11)
without altering the DSN (Deep Space Network) receiver configuration (low
noise). On October 10, commands were sent to switch the data rate back to
40 bps and select the low frequency subcarrier subsequent to the stored
sequence reselecting the high frequency subcarrier. Recent observed
performance shows about 0.5 db link improvement when using the low frequency
subcarrier.
7. Delayed Action Commands (DACs) were sent on October 8 (for execution on
October 9) to turn the S-Band ranging channel on prior to starting TCM-11 in
order to collect navigation data during the maneuver. Subsequent to the
maneuver the ranging channel was then turned off by a DAC.
8. The TCM-11 maneuver was performed on October 9. The maneuver used the
spacecraft's P1A thruster and L-thrusters to impart a positive Z and a lateral
delta velocity. TCM-11 was the first maneuver to be performed at 10 bps and at
Earth pointed attitude.
Prior to the maneuver, the EPD (Energetic Particles Detector) was stepped
to Sector 0, the predicted least contamination position; after the maneuver,
the EPD was repositioned back to Sector 4.
The spacecraft's performance throughout the activity was normal. All the
observed RPM (Retro Propulsion Module) pressures and temperatures and attitude
control indicators were near predicted levels.
It was observed that between the positive Z burn segment and the lateral
burn segment, a sequence planned spin correction was performed; the planned HGA
(High Gain Antenna) correction was not needed. After the lateral burn segment
a planned HGA correction was made but the planned spin correction was not
needed.
Throughout the maneuver activity, the DC bus imbalance measurement
remained stable varying about 1 DN; the AC measurement fluctuated somewhat
during the burn but returned near its pre-burn value.
Preliminary radio tracking data indicates the positive Z segment produced
about 0.5 percent overburn and the lateral segment appeared normal.
9. The AC/DC bus imbalance measurements exhibited some small change. The DC
measurement fluctuated 2 DN and now reads 14.7 volts; the AC measurement
dropped 3 DN and now reads near 44 volts. All other power telemetry and
subsystem telemetry are normal.
10. The Spacecraft status as of end of day October 10 was as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Earth pointed; Sun Point Angle
- approximately 23 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR and NIMS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 288 hours
Time To Initiation - 280 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Project reviewed and approved the TCM-11 sequence memory load on
October 4; the maneuver load was sent to the spacecraft on October 7.
2. Project reviewed and approved the EE-3 (Earth-Earth 3) prime Gaspra
encounter preliminary sequence and command generation product on October 8.
This sequence is scheduled to be sent to the spacecraft on October 27.
3. Project reviewed and approved the EE-4 Part A preliminary sequence and
command generation product on October 9. The EE-4 Part A sequence controls
spacecraft activities from November 4, 1991 to December 4, 1991. November 8
has been aside for the LGA-2 (Low Gain Antenna-2) retract/deploy flight test.
GDS (Ground Data Systems):
1. The Project FPSO change board approved the delivery and on-line request
for the Multimission Image Processing Subsystem (MIPS) Version 5.3. The MIPS
delivery provides Galileo with an on-line backup software Reed-Solomon decoding
capability for Gaspra support in the event the prime hardware Reed-Solomon
decoder capability fails.
2. The Project has conditionally accepted the use of Type B telemetry strings
for Galileo support after a workaround was defined for the telemetry time tag
variations noted in earlier testing. The workaround involves a manual entry of
bit rate to override the value included in the predicts.
TRAJECTORY
As of noon Thursday, October 10, 1991, the Galileo Spacecraft status was
as follows:
Distance from Earth 223,120,210 miles
Distance from Sun 201,102,900 miles (2.16 AU)
Heliocentric Speed 36,150 miles per hour
Distance from Gaspra 8,285,430 miles
Round Trip Light Time 41 minutes, 27 seconds
SPECIAL TOPICS
1. As of October 10, 1991, a total of 5861 real-time commands have been
transmitted to Galileo. Of these, 1928 have been pre-planned in the sequence
design and 3933 were not. In the past week, 29 real time commands were
transmitted; of these eleven were pre-planned. In addition, 1927 mini-sequence
commands have been transmitted since March 1991 (24 were transmitted this
week for the UVS data). Major commanding activities this week included
resetting the command loss timer, TCM-11 memory load, attitude control wobble
ID, telemetry data rate selections, DACs for ranging navigation data, low
frequency subcarrier selection and the retrieval of UVS Lyman Alpha data.
2. The Gaspra Readiness Review will be held at JPL on October 14; Gaspra
closest approach will occur on October 29 at a range of about 1000 miles.
3. The sixth HGA anomaly review board meeting will be held at JPL on
October 18. Meeting topics will focus on the LGA-2 retract/deploy flight test
and plans for the December 91 cooling turn.
4. The third HGA cooling turn activity is scheduled to be performed between
December 4 through December 19.
5. Two more unexplained CDS (Command Data Subsystem) lock changes occurred
on October 9 while over DSS-14 (Goldstone 70 meter tracking station). This is
the 12th occurrence of this event. As with the other events, there was no
evidence that a command was received, processed or issued by the CDS. The CDS
has properly executed all planned commands. A summary status report to Project
covering all the events is scheduled for November 5.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.493 | Update - October 14 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Oct 14 1991 21:44 | 36 |
| Article: 17472
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/14/91
Date: 15 Oct 91 01:44:40 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 14, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Yesterday, the spacecraft shuttered the third of the four planned
optical navigation images. This image, known as OPNAV #4, will be
retrieved over the next week using DMS (Data Management Subsystem) MRO
(Memory Readout) activities. Imaging instrument (SSI) memory readouts
were also performed to verify the instrument's health.
Today, a routine command will be sent to reset the command loss
timer. DMS MRO activities for the OPNAV #4 will continue.
Tomorrow, the OPNAV#4 image playback will continue.
Today, the GASPRA Encounter Readiness Review is being held at JPL.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.494 | Update - October 15 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Oct 16 1991 19:05 | 31 |
| Article: 17494
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/15/91
Date: 15 Oct 91 21:40:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 15, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
The third of four planned optical navigation images, known as OPNAV#4, is
being retrieved; more than 30 percent of the image will have been returned by
1700 PDT, today.
Tomorrow, the image playback activity will continue. Additionally, an
imaging instrument (SSI) memory readout and an RPM (Retro Propulsion Module)
thruster maintenance activity are scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | For every rule, there is
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | an exception. There is no
|_____|/ |_|/ |_____|/ | exception to this rule.
|
| 560.495 | Update - October 16 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Oct 17 1991 15:48 | 33 |
| Article: 17539
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/16/91
Date: 17 Oct 91 05:33:55 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 16, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Today, the playback of the third optical navigation image
(OPNAV#4) will continue. By end of day, more than 50 percent of the
image will be retrieved. Additionally, an imaging instrument (SSI)
memory readout and an RPM (Retro Propulsion Module) thruster
maintenance activity are scheduled.
Tomorrow, the playback of the optical navigation image will
continue. Also a planned routine command will be sent to reset the
command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.496 | GALILEO's encounter with planetoid Gaspra | MTWAIN::KLAES | All the Universe, or nothing! | Thu Oct 17 1991 15:48 | 160 |
| Article: 17545
From: HIGGINS@FNALA.FNAL.GOV (Bill Higgins-- Beam Jockey)
Newsgroups: sci.astro
Subject: Galileo encounters Gaspra (long)
Date: 17 Oct 91 10:14:01 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
At IAF in Montreal last week, I snagged a copy of IAF-91-468, "Project
Galileo Mission Status," by William J. O'Neil of JPL. I thought I
knew all about Galileo's status from reading the bulletins available
on The Net, but one glance at this paper convinced me that I needed to
read it. It includes graphics illustrating the Venus, Earth, and
Gaspra encounters as well as the spacecraft's trajectory through the
solar system and its pinball game among the Jovian moons. It also has
diagrams and photos that make the plight of the jammed high-gain
antenna (HGA) clearer.
I decided that all this juicy stuff would be helpful in putting
together my lecture and slideshow on Galileo, coming soon to an
astronomy club, planetarium, or museum near you.
You can obtain a photocopy of the paper for US$10 or a microfiche for
US$4 from AIAA Technical Information Service, 555 West 57th St., New
York, NY, (212)247-6500. But they'd never get it to you in time for
the Gaspra encounter, so if you'll indulge me, I shall summarize.
Galileo's closest approach to Gaspra will be at 2237 GMT on Monday, 29
October (1637 Chicago time; we'll be off Daylight Saving Time by
then). It will pass within about 1600 km of the asteroid, overtaking
it from behind in its orbit around the Sun, with a relative speed of 8
km/sec and about 145 degrees from the Sun-to-Gaspra line.
Alas, the position of the asteroid is uncertain to hundreds of
kilometers. To narrow that down, Galileo shoots "optical navigation
frames," pictures which show Gaspra against a star background, in the
weeks before the encounter. Had the HGA been functional, the
spacecraft would have shuttered forty opnav images. With no choice
but to squeeze the images through the 40-bit-per-second channel of the
low-gain antenna, only four frames are being taken. The first couple
of frames took many days to transmit, but this week soon the Deep
Space Network has dedicated large antennas to continuous coverage of
Galileo for a couple of weeks during the encounter, and the final
opnav frame, OPNAV#5, will come faster. These frames are multiple
exposures, by the way, which I suppose show Gaspra as a series of dots
or a dotted line of streaks. This is nearly as good as having several
separate frames.
OPNAV#4, arriving today, will be used in the final tweak of the orbit,
Trajectory Correction Manuver TCM-12, on 24 October. OPNAV#5, to be
shuttered next Saturday, will help in planning the final camera
pointing for mosaics (narrow-angle, high-resolution frames cover only
tens of kilometers at the encounter distance).
The two instruments of greatest interest in studying Gaspra will be
the Solid State Imaging system (SSI) and the Near-Infrared Mapping
Spectrometer (NIMS). Might as well reel off the specs, since I have
the paper in front of me. The SSI has a 1500-mm, f/8.5 camera,
imaging onto an 800x800-pixel CCD array, 8 filters and a 0.47-degree
field of view. The NIMS is a low-resolution imager... but behind each
pixel is an infrared spectrogram. Slice the data across, you have an
image taken in a narrow "color" range. Slice it lengthwise, and you
have a spectrum. Range is 700-5200 nanometers, resolution is 30
nanometers. Hmm, the pixel resolution isn't in the paper. Let me go
out to my car...
....here we are. (What? You don't carry Galileo's instrumentation
specs in your car? I do. Along with empty Canadian coffee cups from
half a dozen restaurants along Highway 401.) Optics: 9-inch aperture
(aargh-- call it 225 mm), 800-mm focal length, f/3.5... ah, yes,
here. A "nimsel" is 0.52 milliradians square (egad, we're mixing
degrees and milliradians, too!), a NIMS image is 20 x 14 pixels, and
each pixel represents 204 channels of wavelengths. (Since it's a
scanning instrument, its field of view is really only 20 x 1 pixel,
and it takes a few seconds to acquire its data.)
Best guess for Gaspra's dimensions is 10 x 11 x 18 km, rotating with a
7-hour period. It's an S-type main-belt asteroid. Its orbit is
inclined 4.1 degrees; Galileo's first Earth encounter kinked its orbit
4.5 degrees out of the ecliptic to meet the asteroid, and I suppose
the second Earth encounter will take the kink out so it can meet
Jupiter's inclination of about one degree.
Reading approximate times off the chart in the paper (maybe JPL will
publish a more exact timeline soon?), I get:
Time to Diameter Phase Angle Event
Closest (pixels) (degrees)
Approach of Gaspra
-9hr to -1hr 1-44 < 36 Periodic color images/NIMS
spectra
-55 min 50 38 Color image
-50 min 56 39.7 NIMS spectra
-45 min 60? 40 Best "non-tweak" image
-42 min 65-80? 40.7 NIMS spectra
-39 to 29 80-90 40.3 Best color image (mosaic of 27,
3 filters -> total 9 color frames)
-30 to -17 91-150 44 NIMS spectra
-16 to -9 over 250 44-60 Best image, high resolution/high
phase (near the center of
Gapra's most probable position;
pray there's something there!),
49 monochrome frames
After CA Particles-and-fields data,
plasma wave data
Whenever NIMS or SSI images are not being recorded, data from
fields-and-particles experiments will be written to the tape recorder.
We won't see these pictures or spectra for quite a while. :-( They'll
sit on Galileo's tape recorder until the HGA unfolds successfully, or
until Galileo approaches Earth in December 1992 and the low-gain
antenna can support a high data rate again. As usual, we can expect
the Galileo investigators to hang on to the data for a year (except
for a few PR images and "instant science" results), then release it to
the public.
The paper doesn't seem to mention Galileo's two other optical
instruments, the Ultraviolet Spectrometer (probably nothing
interesting for it to look at) and the Photopolarimeter-Radiometer. I
wonder if the PPR could be used in some kind of search for dust clouds
associated with Gaspra? Well, there is a dust detector aboard.
Other tidbits from O'Neil's paper:
--In December 1991 they'll try an "agressive" cold soak near aphelion
to try to pop the stuck ribs out of the HGA. If that doesn't work,
they'll do hot-cold cycling later in 1992.
--In extremis, the atmosphere Probe mission can be done without the
HGA, though the Orbiter would have to play back recorded Probe data to
Earth at an excruciating 10 bits per second.
--There will be a group of Venus-encounter papers published in *Science* soon.
--Decision on whether to encounter the asteroid Ida will be made next
June. If so, the flyby occurs on 28 August 1993; if not, Galileo
saves 35 kg of propellant.
--The 8 December 1992 Earth-Moon encounter will image the Moon's north
pole, get NIMS images of the surface, and make an Earth-Moon movie
starting 8 days after closest approach.
--Interesting new reference: Erickson, J.K., "The Galileo Orbiter:
Command and Telemetry Subsystems on Their Way to Jupiter," *IEEE
Network Magazine,* September 1990. I guess I'll have to chase this
one down.
This has been long-winded, but I hope you found it informative. I've
been pretty hungry for details on the Gaspra encounter, and I presume
there are other readers out there with the same appetite.
O~~* /_) ' / / /_/ ' , , ' ,_ _ \|/
- ~ -~~~~~~~~~~~/_) / / / / / / (_) (_) / / / _\~~~~~~~~~~~zap!
/ \ (_) (_) / | \
| | Bill Higgins
\ / Fermi National Accelerator Laboratory
- - Bitnet: HIGGINS@FNALB.BITNET
~ Internet: HIGGINS@FNAL.FNAL.GOV
SPAN/Hepnet/Physnet: 43011::HIGGINS
|
| 560.497 | Update - October 17 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Oct 17 1991 18:38 | 38 |
| Article: 17555
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/17/91
Date: 17 Oct 91 21:12:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 17, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Yesterday, the spacecraft completed the planned imaging
instrument (SSI) memory readout and RPM (Retro Propulsion Module)
10-Newton thruster maintenance activities.
Today, playback of the OPNAV#4 image will continue; by end of
day, about 80 percent of the image will be retrieved.
Tomorrow, the optical navigation playback activity will continue.
The sixth meeting of the HGA Anomaly Special Review Board will be
held at JPL on October 18.
[Tomorrow is also the two year anniversary of the Galileo launch from
the Space Shuttle - rb]
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.498 | Galileo Status Report - 10/18/91 | PRAGMA::GRIFFIN | Dave Griffin | Mon Oct 21 1991 21:30 | 31 |
| PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109
GALILEO STATUS REPORT
October 18, 1991
Today is the second anniversary of Galileo's launch on
October 18, 1989, from Kennedy Space Center, Florida.
The spacecraft is operating normally in dual-spin mode,
in which part of the craft spins and part remains fixed in
relation to space.
Ground controllers today completed the retrieval of the
third photo of the asteroid Gaspra used for optical navigation as
Galileo closes in on the asteroid for its October 29 flyby. A
fourth optical-navigation picture will be taken on Monday.
The spacecraft is transmitting telemetry at 40 bits per
second (bps), but the rate will be dropped to 10 bps Sunday
consistent with performance predictions.
Galileo is 390 million kilometers (243 million miles)
from Earth and 7.8 million kilometers (4.8 million miles) from
Gaspra today, traveling at a heliocentric velocity of 57,400
kilometers per hour (35,700 miles per hour).
|
| 560.499 | Galileo Status Report - 10/22/91 | PRAGMA::GRIFFIN | Dave Griffin | Tue Oct 22 1991 20:39 | 28 |
| From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/22/91
Date: 22 Oct 91 20:38:32 GMT
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 22, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Today, playback of the Op Nav #5 image shuttered yesterday will continue
using the DMS (Data Management Subsystem) MRO (Memory Readout) activity; by end
of day about 20 percent of the image will be retrieved. Complete retrieval is
expected by October 27.
Tomorrow, the Op Nav #5 playback activity will continue and a command will
be sent to reset the Command Loss Timer. Additionally, the TCM-12 (Trajectory
Correction Maneuver 12) memory load will be sent.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.500 | Gaspra Fact Sheet | PRAGMA::GRIFFIN | Dave Griffin | Tue Oct 22 1991 20:39 | 133 |
| From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Date: 22 Oct 91 21:38:31 GMT
Organization: Jet Propulsion Laboratory
Just got this from PIO - hope this answers a lot of questions - Ron Baalke.
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
GALILEO AT ASTEROID GASPRA
GENERAL DESCRIPTION
On October 29, 1991, the Galileo spacecraft will fly near
the asteroid Gaspra and obtain the first close-up pictures and
other scientific data from an object of this kind.
The spacecraft will approach Gaspra from a direction 33
degrees away from the sun line at a relative velocity of 17,600
miles per hour (8 kilometers per second). Its closest approach
will occur at about 2:37 p.m. PST Tuesday October 29, and will be
about 1,000 miles (1,600 kilometers) from the asteroid on the
shady side.
At this time Galileo and Gaspra will be almost 255 million
miles from Earth and nearly 205 million miles from the Sun. One-
way communication time from the spacecraft to the ground-based
tracking stations will be almost 23 minutes.
All the planets in the Solar System except Pluto, and most
of their satellites, a major comet and the interplanetary medium
have been scientifically studied at close range, and some in
direct contact. However, until now, asteroids have been observed
only at great range, from Earth-based telescopes.
Gaspra is an S-type asteroid, believed to be composed of a
mixture of rocky and metallic minerals, orbiting about 205
million miles from the sun, near the inner edge of the Asteroid
Belt. It was discovered in 1916 by G. Neujmin at the Simeis
Observatory in the Ukraine.
Though of relatively high reflectivity (about 20 percent),
Gaspra is small, with an average diameter of 7.7 miles (12.4
kilometers), and is fairly faint in terrestrial telescopes. For
comparison, the largest asteroid, Ceres, is about 570 miles in
diameter. Gaspra's shape is irregular, with dimensions estimated
to be 6.2 by 6.8 by 11 miles (10 by 11 by 18 kilometers). It
rotates once in 7 hours.
Galileo is on its way to Jupiter by way of gravity-assist
flyby encounters of Venus and the Earth; the Gaspra encounter,
which will have no gravitational effect on the flight path,
occurs between the first and last Earth flybys.
The spacecraft is designed to study Jupiter's atmosphere,
both directly, through an entry probe, and remotely; to observe
the major satellites by remote sensing; and to measure directly
the fields and particles surrounding the planet in space. The
remote-sensing and fields-and-particles instruments will observe
Gaspra as they did Venus and the Earth; their data will be stored
in Galileo's tape recorder as were the pictures and other data
from Venus.
Gaspra's position and motion, like those of most asteroids
its size, are known from Earth-based observations well enough to
find it for further telescopic studies, but the uncertainty would
be far too great to support spacecraft navigation and precise
camera pointing. When it was selected for a Galileo flyby, a
number of observational astronomers undertook to pinpoint the
tiny body more precisely, bringing the uncertainty down to less
than 120 miles (200 kilometers).
However, even this is too uncertain for Galileo's precise
needs. The spacecraft will have to do its own observational
astronomy, looking at the asteroid against the star background,
to refine knowledge of its location. These optical navigation
activities, in September and mid-October, provide images of
Gaspra only as a point of light in the sky, but are invaluable in
correcting the camera-pointing for the actual encounter. This
information will be accurate only to about 30 miles (50
kilometers), and for Galileo's last and closest picture, the
camera must search an area 200 times the size of the asteroid to
be sure of capturing it.
As the spacecraft approaches Gaspra from near the direction
of the Sun on October 29, it will take its first scientific
images and spectra only a few hours away from the tiny asteroid.
During these observations and for a brief interval near closest
approach, Galileo will record fields and particles measurements.
It will take a total of 150 images (a single color picture
requires three images) during the Gaspra encounter; of these, 126
will be acquired during the last hour before closest approach.
About 25 minutes before closest approach and again at about
10 minutes before, the spacecraft camera will track out a mosaic
of image frames to be sure of capturing the asteroid once each
time, even though its position will be too uncertain to permit a
single frame. The first of these will result in one rather small
color picture; the second will provide one more picture, black
and white, relatively large--perhaps a quarter of the picture's
width--and at the best angle for shadows to reveal the asteroid's
topography.
No pictures will be attempted at the closest approach,
because of the uncertainty in arrival time and the high relative
speed. After closest approach, the body of the spacecraft would
block Gaspra from sight, and by the time Galileo could turn to
view the asteroid, they would be too far apart for useful
imaging.
Galileo's images and other Gaspra data will be recorded on
the spacecraft tape recorder for later playback to the
scientists; none will be transmitted to Earth in real time.
Because Galileo's high-gain antenna is not fully deployed, the
spacecraft must use its low-gain antenna, and the data rate is
too low to permit immediate transmission of these extensive
science data sets. As soon as the high-gain antenna is made
fully operational, or when the spacecraft comes close enough to
Earth in late 1992, the Gaspra data will be available.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.501 | GALILEO at Gaspra | MTWAIN::KLAES | All the Universe, or nothing! | Thu Oct 24 1991 00:03 | 215 |
| Article: 1711
From: clarinews@clarinet.com
Newsgroups: clari.tw.space,clari.news.features,clari.news.interest
Subject: UPI Special Report: Galileo at Gaspra
Date: 23 Oct 91 01:30:47 GMT
_a_d_v_ _w_e_e_k_e_n_d_ _o_c_t_
_2_6_-_2_7_ _o_r_
_t_h_e_r_e_a_f_t_e_r
_G_a_l_i_l_e_o_ _p_r_o_b_e_
_s_a_i_l_s_ _t_o_w_a_r_d
_F_i_r_s_t_ _a_s_t_e_r_o_i_d_
_f_l_y_b_y
_B_y_ _W_I_L_L_I_A_M_
_H_A_R_W_O_O_D
_U_P_I_
_S_c_i_e_n_c_e_ _W_r_i_t_e_r
Aimed with uncanny precision, NASA's $1.4 billion Galileo Jupiter
probe will sail past a tiny asteroid Oct. 29, snapping some 150 pictures
just before a 1,000-mile flyby to give scientists their first close-up
look at a relic of the solar system's birth.
While problems with the probe's partially deployed main radio antenna
will delay the transmission of pictures and data, scientists said the
flyby marked another major milestone in humanity's exploration of the
solar system.
``I would regard (this) as kind of the first stage in any
exploration, to get a good picture of it,'' said Galileo project
scientist Torrence Johnson. ``Taking a look at one of these places for
the first time gives you a lot of information.''
Following a convoluted trajectory toward a 1995 encounter with
Jupiter, the nuclear-powered Galileo is scheduled to pass within about
1,000 miles of a small, potato-shaped asteroid named Gaspra at 5:37 p.m.
EST on Oct. 29.
The brief encounter will take place 255 million miles from Earth
while Galileo streaks through space at 17,600 mph relative to the sun.
Starting a few hours before closest approach, Galileo's cameras will
begin taking the first detailed pictures ever made of an asteroid, one
of thousands of small, rocky bodies orbiting the sun in a broad belt
between the orbits of Mars and Jupiter.
Because of uncertainty in Gaspra's position -- the asteroid averages
just 7.7 miles wide -- Galileo's cameras will sweep a large area of the
sky, taking 150 photos that will be combined into mosaics to make sure
of capturing useful images of the slowly rotating body.
The last photo, a black-and-white image, is scheduled a scant nine
minutes before closest approach. If all goes well, scientists will end
up with a series of color and black-and-white photos providing an
unprecedented glimpse at an ancient relic of the solar system's formation.
``It will partially depend on luck,'' Johnson said. ``One of the
things that makes this encounter tricky is we don't know precisely where
the asteroid is. So during closest approach, during the 10 minutes when
we're taking our best data, we'll be scanning a rather large volume of
the sky.
``We're going to have to take 50 to 60 pictures just to ensure
that we've got Gaspra in one of them. Exactly when in that sequence we
actually hit Gaspra with a picture will determine how big it is in the
picture.''
Galileo image analysts at NASA's Jet Propulsion Laboratory in
Pasadena, Calif., measure the width of a Galileo picture in units called
``pixels.'' One frame is 800 pixels wide. Depending on where Gaspra
actually is, the resulting image could be as small at 150 pixels wide or
as large as 270.
``It'll be comparable to a lot of those pictures of the smaller
satellites of the outer planets that Voyager took,'' Johnson said.
But because of problems with Galileo's main antenna, the pictures
will be stored on magnetic tape for playback during a flyby of Earth in
1992 or until engineers get the spacecraft's jammed ``high-gain''
antenna to open.
Galileo was launched from the space shuttle Atlantis Oct. 18, 1989,
kicking off a six-year, three-planet celestial billiard shot requiring
the probe to sail once past Venus and twice past Earth for velocity-
boosting gravity-assist flybys required to fling the probe on to distant
Jupiter.
The spacecraft zoomed past Venus and Earth in 1990, gaining enough
speed during the second flyby to reach the asteroid belt between Mars
and Jupiter. After the Gaspra flyby, Galileo will fall back into the
inner solar system for a second flyby of Earth on Dec. 8, 1992.
After that, Galileo will move out for a second asteroid flyby and
then on to distant Jupiter. If all goes well, the spacecraft will drop
an instrumented probe into Jupiter's stormy atmosphere before the
mothership slips into orbit around the giant planet in December 1995 for
a planned 20-month tour.
Sailing through a ballet of ever-changing orbits, Galileo's
electronic ears and eyes will study Jupiter's atmosphere, its whirling
moons and its space environment in exquisite detail, beaming back close-
up photographs 20 to 1,000 times better than the spectacular pictures
taken by the Voyager probes.
How much of that data makes it back to Earth depends on the high-gain
antenna.
Galileo's $2.7 million main antenna, needed to transmit pictures and
science data back to Earth, is made of gold-plated molybdenum mesh
stretched across 18 graphite-epoxy ribs connected by quartz wire. The
dish-shaped antenna was designed to open in space much like an umbrella.
Because of Galileo's convoluted trajectory, the 75-pound 16-foot-wide
antenna had to be kept closed until after the first Earth flyby to
prevent the fragile mesh from being damaged by heat from the sun.
Finally, on April 11, Galileo's on-board computer system executed stored
commands to open the antenna.
To the dismay of engineers monitoring the procedure at JPL, the
antenna failed to fully deploy. Data indicates two or three of the 18
ribs are stuck to the antenna's central tower, possibly because of a
loss of lubrication.
Engineers are optimistic the stuck ribs will pop free if the
spacecraft can be chilled enough in the deep cold of space to cause the
central column to contract slightly.
The first such ``chilldown'' last month failed and another attempt is
planned for December. Along with cooling the antenna by orienting it
away from the sun, engineers also plan to jar Galileo slightly by
ordering it to stow and then redeploy its smaller low-gain antenna.
If the stuck ribs still refuse to budge, engineers are considering a
variety of less attractive options, including small rocket firings to
jar the antenna, along with alternating hot-and-cold cycles.
Without the use of the high-gain antenna, Galileo's smaller low-gain
antenna would need some 12 days to transmit a single image of Jupiter,
two years to beam back a maximum of 60 or so pictures compared to the
thousands it was designed to take during the same period.
While many engineers are optimistic they will eventually succeed in
coaxing the antenna open, others are not so sure, rating the odds of
success at 50-50. In the meantime, ground crews are pressing ahead and
gearing up for the Gaspra encounter.
------
Discovered in 1916, Gaspra rotates once every seven hours. It orbits
the sun at a distance of some 205 million miles and measures 6.2 X 6.8 X
11 miles. Gaspra is a ``type-S'' asteroid, meaning it is made up of a
mixture of rocky and metallic minerals.
``If you watch it every seven hours it varies greatly in brightness,
it's a chunk of stuff that's rotating out there,'' Johnson said. ``We
might actually be able to see parts of it that are quite different from
other parts. Perhaps it came from the interior of a larger body. There
are no guarantees. This is one of those games where you don't know what
you've got until you actually see it.''
The first asteroid was discovered in 1801 and astronomers still do
not completely understand their origin and history. It once was believed
they might be the shattered remnants of a destroyed planet, but that
clearly is not the case.
``One of the things to remember is the asteroid belt is not very
massive,'' Johnson said. ``If you put all that stuff together you don't
even get a reasonable size chunk of the moon. So it's not a busted up
planet or something like that.''
Instead, the chunks of debris orbiting between Mars and Jupiter more
likely are ``the Darwinian survivors of the planetary formation process.''
``They're the guys who just happened to be in the right dynamical
niches, if you will, so that they didn't get collected up by the other
planets when everything was being swept up in the formation of the solar
system,'' Johnson said. ``As such, they kind of provide us clues ... as
to the types of things that were there 4 billion years ago before things
got into planets.''
Astronomers believe the sun, the planets and their many moons
coalesced from a huge cloud of dust and debris some 4.5 billion years
ago. During the early stages of the solar system's formation, collisions
broke up larger asteroids and gravitational interactions caused the
asteroid belt to thin out.
``What we see out there probably started with a distribution of large
and small bodies that got ground down to the smaller bodies, a lot of
the stuff got kicked out and so forth,'' Johnson said.
While Galileo's flyby represents humanity's first attempt to examine
an asteroid at close range, quite a bit is known about the rocky bodies.
In fact, it is believed that most of the meteorites that are found on
Earth originated in the asteroid belt.
In addition, the martian moons Phobos and Deimos could be asteroids
that were captured by Mars's gravity. While they have been studied in
some detail, their very location makes them different from the members
of the main belt.
``A lot of people think maybe asteroids will look like Phobos and
Deimos,'' Johnson said. ``Maybe they will and maybe they won't. There
are some reasons to think that Phobos and Deimos, because of their
unique history of being in Mars' gravity, might look rather different
even in detail from asteroids.
``For instance, stuff that got kicked off the surfaces of those
bodies, Phobos and Deimos, by micrometeroids would just orbit around
Mars and get re-collected by them. So their appearance is even shaped by
the fact that they're (orbiting) around Mars.''
_a_d_v_ _w_e_e_k_e_n_d_ _o_c_t_
_2_6_,_2_7_ _o_r_
_t_h_e_r_e_a_f_t_e_r
|
| 560.502 | Update - October 23 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Oct 24 1991 19:49 | 97 |
| Article: 17773
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 10/23/91
Date: 24 Oct 91 02:09:01 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
October 23, 1991
The Galileo spacecraft is more than 248 million miles from Earth,
making the one-way communication time 22 minutes 15 seconds. It is
203.7 million miles from the Sun, and its speed in orbit is 35,422
miles per hour.
Galileo is operating normally in the dual-spin mode, transmitting
coded telemetry at 40 bits per second over the low- gain antenna. The
telemetry includes part of the fourth optical navigation image,
showing Gaspra's position against the star background.
Today the flight team is sending Galileo the sequence of commands
for tomorrow's maneuver, which will fine-tune the aiming for next
Tuesday's encounter with the asteroid Gaspra.
This maneuver, which begins aboard the spacecraft at about 10
a.m. PDT October 24, is a small one, requiring a total of 104 tiny
pulses, mostly from the lateral thrusters. It will change the
spacecraft velocity by less than 1 mile per hour, mostly sidewise to
the flight path, delaying arrival at Gaspra by 3 seconds and moving
the close-approach point slightly. This should permit the best
possible observations of Gaspra.
Galileo's Gaspra encounter will take place as scheduled, with
closest approach of 1,000 miles at 2:37 p.m. PST October 29
(spacecraft event time). All scientific data, including pictures
taken down to 9 minutes before close approach, will be tape- recorded
for playback to Earth in 1992.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
Article: 17785
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Asteroid Flyby Briefing Scheduled
Date: 24 Oct 91 19:46:59 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Paula Cleggett-Haleim
Headquarters, Washington, D.C. October 24, 1991
(Phone: 202/453-1549)
EDITORS NOTE: 91-74
GALILEO ASTEROID FLYBY MEDIA BRIEFING SCHEDULED
NASA's Galileo spacecraft will achieve the first close
encounter with an asteroid, called Gaspra, at 5:37 p.m. EST on
Tuesday, Oct. 29.
At 6:30 p.m. that evening, a briefing will be held at the Jet
Propulsion Laboratory, Pasadena, Calif., to provide spacecraft and
mission status. No real-time pictures or scientific data will be
available from this encounter in real time. Such information will be
recorded for playback in 1992 when conditions permit.
Galileo Project Manager William J. O'Neill and Project
Scientist Torrence V. Johnson will conduct the briefing and respond to
questions. The briefing will be carried live on NASA Select
television, Satcom F2R, transponder 13, C-band, 72 degrees west
longitude, frequency 3960 MHz.
A fact sheet and line drawing depicting the flyby are
available through the NASA Headquarters Newsroom (202/453-8400).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.503 | Update - October 24 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Oct 25 1991 19:23 | 32 |
| Article: 17808
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/24/91
Date: 25 Oct 91 04:16:26 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
GALILEO STATUS REPORT
October 24, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Earlier today, another partial playback of the Op Nav #5 image was
completed; about 50 percent of the image is now retrieved.
Today, the TCM-12 (Trajectory Correction Maneuver 12) will be performed;
the first burn pulse will occur about 1000 PDT. The maneuver is planned to
impart a delta velocity of about 0.33 m/sec using the axial (Z) thrusters and
lateral (L) thrusters.
Tomorrow, the playback of the Op Nav #5 image will continue; at end of
day Friday (midnight) about 70 percent of the image will be retrieved.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.504 | Update - October 25 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Oct 25 1991 20:37 | 147 |
| Article: 17832
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/25/91
Date: 25 Oct 91 22:10:49 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
October 18 - 24, 1991
SPACECRAFT
1. The third image (OPNAV #4) of the four optical navigation images was
totally retrieved, as planned, on October 18. Data from the image was used to
update the previously approved TCM-12 (Trajectory Correction Maneuver 12)
design scheduled for October 24. The previously approved TCM-12 was designed
as a single segment lateral maneuver imparting a delta velocity of about
0.21 m/sec. The updated design, using OPNAV #4, is a two segment maneuver
imparting a delta velocity of about 0.33 m/sec and consist of a single axial
(-Z) and a single lateral (L) burn segment.
2. A SITURN was performed on October 20 in preparation for shuttering the
fourth optical navigation image (OPNAV#5). The 27-degree turn resulted in the
spacecraft leading the sun about three degrees. Subsequent to taking the
OPNAV#5 image, another SITURN to return to Earth pointed attitude was
performed.
The total OPNAV#5 image is planned to be retrieved by October 27; as of
today about 50 percent of the image has been retrieved via the DMSMROs (Data
Management Subsystem Memory Readouts) performed on October 21, 22, and 23.
3. Imaging instrument (SSI) Memory Readouts (MRO) to verify the health status
of the SSI were completed on October 21 (one prior to and one after the
shuttering of the OPNAV#5 image); another SSI MRO was performed on October 23.
4. The CDS (Command Data Subsystem) command loss timer was changed on
October 21 from 12 days to 3 days consistent with the Gaspra encounter plan.
Commands were sent, as planned, to reset the command loss timer on October 22
and 23.
5. A MAG (Magnetometer) , DDS (Dust Detector) and EPD (Energetic Particles
Detector) instrument memory readout activity was completed on October 23.
6. The TCM-12 maneuver was performed on October 24. The maneuver used the
spacecraft's axial (Z) thrusters and lateral thrusters to impart a delta
velocity to trim to the Gaspra aim point. This maneuver, like the TCM-11,
was executed at 10 bps and at Earth pointed attitude.
Prior to the maneuver on October 23, the EPD was stepped to Sector 0 the
predicted least contamination position; after the maneuver, the EPD will be
positioned back to Sector 4 on October 25.
The spacecraft's performance throughout the activity was normal. All RPM
(Retro Propulsion Module) pressures and temperatures and attitude control
indicators were near predicted levels. After the axial and lateral burn
segments, the sequence planned spin correction and pointing corrections were
not needed. Throughout the burn activity, the AC/DC bus imbalance measurements
were quite stable and fluctuated only 1 DN.
Preliminary radio tracking data indicates less than 0.5 percent overburn
for the axial segment; the lateral burn segment appeared normal.
7. Commands were sent on October 20, 21, and 24 to reconfigure the telemetry
subcarrier frequency and the telemetry data rate to be compatible with planned
SITURN, TCM-12 and DMSMRO activities. The command actions selected either the
360 khz or 22.5 khz subcarrier frequency and either the 40 bps or 10 bps data
rate consistent with link performance and activities being performed.
8. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 3 DN and now reads 14.7 volts; the AC measurement
fluctuated 5 DN and now reads near 44.4 volts. All other power telemetry and
subsystem telemetry are normal.
9. The Spacecraft status as of end of day October 24 was as follows:
a) System Power Margin - 67 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Earth pointed; Sun Point Angle
- approximately 20.5 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR and NIMS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 72 hours
Time To Initiation - 63 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Project reviewed and approved the TCM-12 update maneuver navigation
design and spacecraft implementation on October 20 and 21, respectively; this
maneuver design is based, in part,on Optical Navigation Image #4 data. TCM-12
was performed on October 24; the memory load was sent to the spacecraft on
October 23.
GDS (Ground Data Systems):
1. The Galileo flight teams have not reported any significant Ground Data
System problems in early Gaspra operations support. Sequencing software has
been used extensively in preparing uplinks for TCM 11/12 and EE-2/3'
(Earth-Earth sequencing), and in the uplink tweak training exercises with no
significant problems. The FCSO reports real time MCCC (Mission Control &
Computing Center) and DSN (Deep Space Network) support continues to be
excellent with almost all data for optical navigation replays being
successfully recovered. A momentary glitch in the Frequency and Timing
Subsystem at SPC-10 (Signal Processing Center 10, Goldstone) on Tuesday
caused DSS-14 (70 meter Goldstone antenna) to drive off point resulting in a
temporary outage. Quick action by DSS-14 operations personnel to reload
pointing predicts restored service before significant data loss had occurred.
TRAJECTORY
As of noon Thursday, October 24, 1991, the Galileo Spacecraft status was as
follows:
Distance from Earth 249,435,530 miles (2.69 AU)
Distance from Sun 203,882,380 miles (2.19 AU)
Heliocentric Speed 35,370 miles per hour
Distance from Gaspra 2,263,780 miles
Round Trip Light Time 44 minutes, 30 seconds
SPECIAL TOPICS
1. As of October 24, 1991, a total of 5884 real-time commands have been
transmitted to Galileo. Of these, 1948 have been pre-planned in the sequence
design and 3936 were not. In the past week, 22 real time commands were
transmitted and 19 were pre-planned. In addition, 1927 mini-sequence commands
have been transmitted since March 1991; (24 were pre-planned and 1903 were not)
and none were sent this week. Major commanding activities this week included
resetting the command loss timer, several data rate and subcarrier frequency
reconfigurations and uplinking the TCM-12 memory load.
2. The Galileo Gaspra encounter closest approach will occur on October 29 at
about 22:37:00 (UTC) at a range of about 1000 miles. The Gaspra encounter
sequence memory load will be sent to the spacecraft on October 27.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.505 | Update - October 25 (#2) | MTWAIN::KLAES | All the Universe, or nothing! | Sat Oct 26 1991 18:17 | 35 |
| Article: 17839
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 10/25/91
Date: 26 Oct 91 01:15:59 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 25, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the spacecraft performed the TCM-12 (Trajectory Correction
Maneuver 12); spacecraft performance throughout the activity was normal.
Today, playback of the Op Nav #5 image will continue; by midnight about
70 percent of the image will be returned. The NIMS (Near Infrared Mapping
Spectrometer) instrument will be powered on at about 1000 hours PDT in
preparation for the upcoming GASPRA encounter activities.
On Saturday, playback of the Op Nav #5 image will continue; on Sunday,
October 27, the EE-3 (Earth-Earth 3) prime GASPRA encounter sequence memory
load is scheduled for transmission over DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.506 | Update - October 28 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Oct 29 1991 10:41 | 115 |
| Article: 17885
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/28/91
Date: 29 Oct 91 04:16:29 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
NOTE TO TV EDITORS AND NEWS DIRECTORS October 28, 1991
NASA's Galileo spacecraft will fly by the asteroid Gaspra at 2:37
p.m. PST on Tuesday, October 29, and there will be a news briefing at
JPL's Von Karman Auditorium at 3:30 p.m. PST that afternoon.
A computer animation video clip to be used in the news briefing
will be transmitted via NASA Select television at 8 a.m. PST October
29. Both video preview and the briefing will be carried live on NASA
Select, which may be accessed via Satcom F2R, Transponder 13, C-Band,
72 degrees west longitude, frequency 3960 Mhz.
#####
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO SPACECRAFT AT ASTEROID GASPRA
OCTOBER 29, 1991
COMPUTER ANIMATION CLIP (1 min 55 sec)
1. Galileo spacecraft rotating, not far from asteroid. About 255
million miles (410 million kilometers) from Earth, 205 million miles
(330 million kilometers) from Sun. Spacecraft weighs about 5,000
pounds (2,200 kilograms), is 20 feet (6 meters) tall, 30 feet in
diameter. The viewpoint shifts past the spacecraft towards Gaspra.
2. Beginning hours before closest approach, Galileo's imaging system
takes several single-frame pictures of the tiny, still-distant
asteroid. Please note that none of Galileo's pictures or other
observations of Gaspra will be available immediately. They will be
recorded by the spacecraft for playback in 1992 when conditions permit.
3. Starting 35 minutes before closest approach, Galileo takes a
9-frame mosaic pattern of full-color images of the area where the
asteroid should be, to be sure of capturing it in one picture.
4. Starting 16 minutes before closest approach, Galileo takes a
49-frame pattern, finishing up at 9 minutes before closest approach in
the likeliest location of the asteroid. One black and white image,
taken at a distance of several thousand miles (or kilometers) and covering
as much as one-fourth of the image frame, is the expected result.
5. Galileo spacecraft rotating (repeat from 1).
6. Scientific simulation of asteroid Gaspra, rotating. About 6 x 7 x
11 miles (10 x 11 x 18 kilometers), it actually rotates once in 7
hours. The viewpoint moves past the sunlit side, looking back at the
night side.
7. Galileo spacecraft rotating, viewing the rotating asteroid. The Los
angeles basin appears below Gaspra to show the size of the asteroid.
The spacecraft will fly by Gaspra at a distance of 1,000 miles (1,600
kilometers) at 22:37 Universal Time (2:37 p.m. PST) on Tuesday,
October 29, 1991.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
Article: 17891
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 10/28/91
Date: 29 Oct 91 05:52:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 28, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
The EE-3 (Earth-Earth 3) prime GASPRA encounter sequence memory
load was sent during the late evening on October 26. The sequence
memory load followed a planned command to reset the Command Loss Timer.
Today, commands will be sent to reset the Command Loss Timer and
to change the telemetry data rate from 40 bps to 10 bps in preparation
for the GASPRA encounter on October 29. The lower data rate permits
dual-site telemetry to enable the PLS (plasma) instrument system fault
protection prior to instrument power on. Subsequently, commands will
be sent to enable the star scanner bright body fault protection for
the GASPRA encounter.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.507 | It's G-Day | MTWAIN::KLAES | All the Universe, or nothing! | Tue Oct 29 1991 16:42 | 96 |
| Article: 1716
From: clarinews@clarinet.com (WILLIAM HARWOOD, UPI Science Writer)
Newsgroups: clari.tw.space
Subject: Galileo streaks toward asteroid flyby
Date: 29 Oct 91 17:57:13 GMT
NASA's $1.4 billion Galileo probe, taking the scenic route to
distant Jupiter, streaked toward a historic asteroid flyby Tuesday
with its cameras primed to snap the first close-up pictures of a
slowly tumbling relic of the solar system's birth.
Galileo's umbrella-like main radio antenna remains jammed in a
partially open position, which will delay the transmission of pictures
and other data until next year at the earliest.
But scientists at NASA's Jet Propulsion Laboratory in
Pasadena, Calif., said they are confident the photos, whenever they
get back, will give them information on the structure and history of
the tumbling rocks making up the asteroid belt between Mars and Jupiter.
Following a convoluted trajectory toward a 1995 encounter with
Jupiter, the nuclear-powered Galileo, sailing through space at some
17, 600 mph relative to the sun, was scheduled to pass within about
1,000 miles of a small, potato-shaped asteroid named Gaspra at 5:37
p.m. EST.
Because of uncertainty in Gaspra's position -- the asteroid
averages just 7.7 miles wide -- Galileo's computer was loaded with
commands to take 150 snapshots that will be combined into mosaics later
to make sure of capturing useful images of the slowly rotating body.
The last photo, a black-and-white image, was scheduled a scant
nine minutes before closest approach. If all goes well, scientists
will end up with a series of color and black-and-white photos
providing an unprecedented glimpse at an ancient relic of the solar
system's formation.
``It will partially depend on luck,'' said project scientist
Torrence Johnson. ``One of the things that makes this encounter tricky
is we don't know precisely where the asteroid is. So during closest
approach, during the 10 minutes when we're taking our best data, we'll
be scanning a rather large volume of the sky.''
Galileo image analysts at JPL measure the width of a Galileo
picture in units called ``pixels.'' One frame is 800 pixels wide.
Depending on where Gaspra actually is, the resulting image could be as
small at 150 pixels wide or as large as 270.
But because of problems with Galileo's main antenna, the
pictures will be stored on magnetic tape for playback during a flyby
of Earth in 1992 or until engineers get the spacecraft's jammed
``high-gain'' antenna to open.
Galileo was launched from the space shuttle Atlantis on Oct.
18, 1989, kicking off a six-year, three-planet celestial billiard shot
requiring the probe to sail once past Venus and twice past Earth for
velocity-boosting gravity-assist flybys required to fling the probe on
to distant Jupiter.
The spacecraft zoomed past Venus and Earth in 1990, gaining
enough speed during the second flyby to reach the asteroid belt
between Mars and Jupiter. After the Gaspra flyby, Galileo will fall
back into the inner solar system for a second flyby of Earth on Dec.
8, 1992.
After that, Galileo will move out for a second asteroid flyby
and then on to distant Jupiter. If all goes well, the spacecraft will
drop an instrumented probe into Jupiter's stormy atmosphere before the
mothership slips into orbit around the giant planet in December 1995
for a planned 20-month tour.
Because of Galileo's convoluted trajectory, its 75-pound
16-foot-wide main antenna had to be kept closed until after the first
Earth flyby to prevent damage from the heat of the Sun. It was ordered
to open on April 11.
To the dismay of engineers monitoring the procedure at JPL,
the $2.7 million antenna failed to fully deploy. Data indicates two or
three of the 18 ribs making up the framework of the dish-shaped antenna
are stuck to a central tower, possibly because of a loss of lubrication.
Engineers are optimistic the stuck ribs will pop free if the
spacecraft can be chilled enough in the deep cold of space to cause
the central column to contract slightly.
The first such ``chilldown'' last month failed and another
attempt is planned for December. Along with cooling the antenna by
orienting it away from the sun, engineers also plan to jar Galileo
slightly by ordering it to stow and then redeploy its smaller low-gain
antenna.
Without the use of the high-gain antenna, Galileo's smaller
low-gain antenna would need some 12 days to transmit a single image of
Jupiter, two years to beam back a maximum of 60 or so pictures compared
to the thousands it was designed to take during the same period.
|
| 560.508 | Update - October 29 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Oct 30 1991 11:32 | 42 |
| Article: 17923
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/29/91
Date: 30 Oct 91 02:09:37 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 29, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps.
Yesterday, the EE-3 (Earth-Earth 3) prime Gaspra encounter
sequence went active as planned. The spacecraft completed a 23-degree
SITURN reorienting from an Earth pointed attitude to a 3.1 degree sun
leading attitude in preparation for Gaspra encounter activities on
October 29. Additionally, the Photopolarimeter (PPR) and Plasma
Science (PLS) instruments were powered. All Galileo instruments are
powered for the encounter.
Today, at about 14:37 PST, Galileo will reach its closest
approach (1000 miles) to the asteroid Gaspra. Remote sensing and
fields and particle science data will be collected and stored on the
tape recorder (DMS). During the encounter period, the imaging
instrument (SSI) will take 150 images; 126 images will be taken within
the last hour near closest approach.
Tomorrow, the PPR, PLS and NIMS (Near Infrared Mapping
Spectrometer) instruments will be powered off; and the command loss
timer will set to 264 hours, the planned post-encounter value.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.509 | Gaspra mission an apparent success | MTWAIN::KLAES | All the Universe, or nothing! | Wed Oct 30 1991 11:33 | 97 |
| Article: 1719
From: clarinews@clarinet.com (WILLIAM HARWOOD, UPI Science Writer)
Newsgroups: clari.tw.space,clari.news.top
Subject: Historic asteroid flyby hailed
Date: 30 Oct 91 00:42:55 GMT
NASA's $1.4 billion Galileo probe, taking the scenic route to
distant Jupiter, streaked past a small potato-shaped asteroid Tuesday,
snapping what scientists hope will be history's first close-up
pictures of a relic of the solar system's birth.
``We've had a great day,'' said mission director Neal Ausman at
the Jet Propulsion Laboratory in Pasadena, Calif. ``Available data indicates
the spacecraft has flawlessly executed the ... encounter sequence.''
Galileo's umbrella-like main radio antenna remains jammed in a
partially open position, which will delay the transmission of pictures
and other data until next year at the earliest.
But scientists at JPL said they were confident the photos,
whenever they get back, will give them priceless information on the
structure and history of the tumbling rocks making up the asteroid
belt between Mars and Jupiter.
``It's disappointing in a way to wait for your Christmas
present, but we have been working on this project for a long time and
just getting to the asteroid was a major step,'' said project scientist
Torrence Johnson. ``We can wait a little longer to get the goodies.''
Following a convoluted trajectory toward a 1995 encounter with
Jupiter, the nuclear-powered Galileo, sailing through space at some
17, 600 mph relative to the sun, passed within about 1,000 miles of a
small, potato-shaped asteroid named Gaspra at 5:37 p.m. EST.
Because of uncertainty in Gaspra's position -- the asteroid
averages just 7.7 miles wide -- Galileo's computer was loaded with
commands to take 150 snapshots that will be combined into mosaics later
to make sure of capturing useful images of the slowly rotating body.
The last photo, a black-and-white image, was scheduled a scant
nine minutes before closest approach. If all goes well, scientists
will end up with a series of color and black-and-white photos
providing an unprecedented glimpse at an ancient relic of the solar
system's formation.
``We believe the asteroids are, in fact, a view back in time
to the origin of the solar system,'' Johnson said. ``They are believed
to be remnants of the original planet-forming material that was
collected into the planets 4 1/2 billion years ago.
``We're interested in these things because we believe they
represent our best shot at looking at the types of things that actually
went into putting planets together back in that period of time.''
Galileo was launched from the space shuttle Atlantis on Oct.
18, 1989, kicking off a six-year, three-planet celestial billiard shot
requiring the probe to sail once past Venus and twice past Earth for
velocity-boosting gravity-assist flybys required to fling the probe on
to distant Jupiter.
The spacecraft zoomed past Venus and Earth in 1990, gaining
enough speed during the second flyby to reach the asteroid belt
between Mars and Jupiter. After the Gaspra flyby, Galileo will fall
back into the inner solar system for a second flyby of Earth on Dec.
8, 1992.
After that, Galileo will move out for a second asteroid flyby
and then on to distant Jupiter. If all goes well, the spacecraft will
drop an instrumented probe into Jupiter's stormy atmosphere before the
mothership slips into orbit around the giant planet in December 1995
for a planned 20-month tour.
Because of Galileo's convoluted trajectory, its 75-pound
16-foot-wide main antenna had to be kept closed until after the first
Earth flyby to prevent damage from the heat of the Sun. It was ordered
to open on April 11.
To the dismay of engineers monitoring the procedure at JPL,
the $2.7 million antenna failed to fully deploy. Data indicates two or
three of the 18 ribs making up the framework of the dish-shaped antenna
are stuck to a central tower, possibly because of a loss of lubrication.
Engineers are optimistic the stuck ribs will pop free if the
spacecraft can be chilled enough in the deep cold of space to cause
the central column to contract slightly.
The first such ``chilldown'' last month failed and another
attempt is planned for December. Along with cooling the antenna by
orienting it away from the Sun, engineers also plan to jar Galileo
slightly by ordering it to stow and then redeploy its smaller low-gain
antenna.
Without the use of the high-gain antenna, Galileo's smaller
low-gain antenna would need some 12 days to transmit a single image of
Jupiter, two years to beam back a maximum of 60 or so pictures compared
to the thousands it was designed to take during the same period.
|
| 560.510 | GALILEO Gaspra Flyby Briefing | MTWAIN::KLAES | All the Universe, or nothing! | Wed Oct 30 1991 11:35 | 427 |
| Article: 17934
From: leech@mahler.cs.unc.edu
Newsgroups: sci.space,sci.astro
Subject: Notes from Galileo Asteroid Flyby Briefing 10/29
Date: 30 Oct 91 00:51:43 GMT
Sender: news@cs.unc.edu
Organization: University Of North Carolina, Chapel Hill
As with the Magellan conference I posted on earlier today, these
are notes I typed in while watching the briefing. I don't guarantee
their accuracy and I can't answer further questions - contact the JPL
Public Information Office (see the FAQ for address of same).
Jon (leech@cs.unc.edu)
__@/
Galileo Gaspra Encounter Press Briefing
10/29/91 3:30 PST
Franklin O'Donnell - JPL PIO - introduction
William O'Neil - Galileo Project Manager
Gailileo encountered Gaspra at 2:37 PST time, within 1000 mi.
Takes 27 minutes to signal, so signal received at 3PM. Been in
continuous radio contact over the last 24 hours. Low bit rate - 10
bits/second. Enough to determine state of spacecraft. Mission
director will discuss how this is used to determine success of
Gaspra observation sequence.
Viewgraph: flight path. 2 years and 11 days into flight today,
currently in a 2 year orbit returning to Earth 12/8/92, arriving
at Jupiter 12/7/95.
Viewgraph: Earth-Earth trajectory segment. Gaspra period 3 1/4
years. inclination angle i = 4.1 degrees. Earth gravity assist
12/8/90 pumped up Galileo orbit and did inclination change to i =
4.5 degrees. Vernier corrections TCM-11 10/9/91, TCM-12 10/24/91
precisely executed, outstanding optical navigation "beyond our
greatest expectations".
Approach velocity 8 km/s (V Galileo = 15.7 km/s, V Gaspra = 20.1 km/s).
Viewgraph: approach geometry from Gaspra POV. Final imaging 16 to
9 minutes before closest approach. Angles and angular rates
climbing as approach. Within 1.5 seconds of targeted encounter time.
Viewgraph: approach geometry. Best estimate is that we hit target
within 5 km (3 sigma ellipse is 75x50 km in B plane). Delta TCA =
-1.5 sec +/- 38 sec (3 sigma) -> about a 300 km uncertainty
perpendicular to B plane. So must build a mosaic which takes into
acount uncertainty.
Viewgraph: Final mosaic covers 200x275 km ellipse in image plane -
51 frames overlaid to guarantee one of the frames would contain
Gaspra to 99% certainty. Designed image sequence on expectation of
navigation accuracy after final optical navigation image received.
Earlier, could only guarantee 95% capture probability. Turned out
that navigation was so superb we reached 99% level.
Concludes preliminary remarks.
Neal Ausman - Mission Director
"We had a great day."
Typically, encounter executed solely from a stored sequence. Not
so for Gaspra. Because of uncertainties in location and ability to
deliver to targeted aim point, flight team had to be prepared to
issue a significant number of last minute instrument pointing
commands which would override the planned sequence.
Viewgraph: Flight Team Preparations Timeline. 3 color overlays.
Loaded EE-3P memory load on Saturday, which was the sequence which
controlled activities today. In case of experiencing problems with
getting OP-NAV image #5 (last of 4), had to be prepared to
exercise a last minute contingency update to spacecraft pointing.
On Saturday, met and decided that due to good tracking
performance, did not need to protect against late, last minute
update [removed blue overlay].
Flight team had trained rigorously for months to do last minute
update. Would have been a very rigorous and tightly scheduled
activity. Were able to eliminate contingency, but still had to be
prepared to change scan platform pointing on a more leisurely
basis (red overlay). Nav team reported that navigation had been so
succesful that no updates were needed [removed red overlay].
Still left with a series of real-time commands. Principally
oriented to reconfigure onboard fault protection and make sure
we're operating at the proper data rate (10 bps throughout).
Scored almost a perfect bullseye with OP-NAV campaign. DSN
performed in a spectacular form.
Everything done today occurred on time and as planned.
Viewgraph: Galileo status. Real-time telemetry confirms sequence
was done. Takes nearly 2 hours to go through full telemetry
commutation table [what's a commutation table? - Jon] -> not much
more than 3 opportunities to see a single measurement at lowest
level. Update rate further decreased by S/C response to telemetry
changes. Results in loss of downlink in ground-based computer
system. This is normal; changes to accomodate rapid set of data
acquisition. But result is that not all channels were available in
real-time. Still sufficient to determine status; in general,
Galileo is performing as predicted. This limitation had no impact
on science data recording, or on execution of the sequence.
Telemetry measurements:
Time Predicted Actual
1506 Tape position
Track 3, Tic 5902 Track 3, tic 5845
Within normal variation.
1505 S/C power margin
87 watts 87 watts
1416 AACS command count (# slew commands)
8397 8397
Received as planned.
1416 Scan platform position
243.3;-20.5 243.3;-20.5
Shutter count change
1429 136 136
Commands were being clocked out and received as planned by AACS
and SSI (solid state image system)
All stored sequence programs were executed properly; all fault
protection indications were as protected
Viewgraph: "Available telemetry indicates the spacecraft has
flawlessly executed the Gaspra Sequence"
William Kirhofer - Navigation Team Chief
Viewgraph: TCM locations for Earth-Earth trajectory leg.
To determine S/C position, combine 3 data times: 2 radiometric
from Earth (very accurate) + astrometric. Accurate to 300-500 km.
Can't go beyond this until optical navigation information is added
(Gaspra against star background).
Picture: OP-NAV image (OPNAV 5, 8 days out). Gaspra and stars are
blurred lines where platform was repositioned.
Objective to measure positions of Gaspra relative to the stars.
Picture: showing measured set of 7 positions of Gaspra on previous image.
Reasons for multiple exposure: [something I didn't catch] + avoid
dropouts of target stars (4 line dropout in OPNAV 5). By Saturday,
knew this was enough to tie down target.
Viewgraph: B-Plane history. 3 sigma ellipses for expectations with
OP-NAV 1, 4, 5.
OP-NAV 1 - 1 pixel = 377 km @ E-53 days.
OP-NAV 4 - 1 pixel = 112 km @ E-16 days
OP-NAV 5 - 1 pixel = 58 km @ E-8 days.
Delta TCA = -1.5 sec, +/- 38 sec (along flight path)
Delta B = 5 km, +/- 78 x +/- 48 km (in B plane)
Some things that helped were flawless performance of navigation
system, and multiple # of points we had to work with, giving very
precise knowledge of position.
Torrance Johnson - Project Scientist
No data to work with yet, but very excited. Expressed admiration
to flight team & entire astronomical community for working on
observations.
Lots of hurdles to overcome: finding an asteroid without
prohibitive propellant penalty, navigation difficulties,
developing sequence taking into account errors. Science & flight
teams worked very hard and it appears to have gone flawlessly.
Short discussion of Gaspra objectives, what was being measured at
closest approach.
Viewgraph: Asteroid Science
- Pluto system & asteroids are the only remaining members of
the solar system not yet visited by spacecraft.
- Asteroids are the remnants of the original planet forming
material collected into planets 4.5 billion years ago.
- Asteroids are not all the same - many different types,
believed to be related to different metorite classes.
- Small asteroids are probably fragments of older, larger
asteroidal objects.
Facetious to claim one flyby by one asteroid will solve all these
questions, but this is the first flyby, and it's an important
first step. Small object - collisions, radioactive heating.
Viewgraph: Gaspra Properties
Provided by planetary astronomy program and international
effort to "target" Gaspra in last two apparations.
Size 10x11x18 km
Albedo ~20% (2x Earth's Moon)
Spectral class "S" - Silicate (Olivene-Rich) type
Rotation period 7.0421 hrs
Rotation axis in orbital plane (+/- 30%)
Viewgraph: "S" Asteroid Controversy
Are "S" asteroids chondrites or stoney-irons?
ordinary chondrites - primitive, unidfferentiated parent
bodies; silicate, chondrules, and iron intimately mixed.
stoney-iron "Thermally evolved", differentiated parent bodies.
Difficult to tell from ground. Galileo multispectral observations
may provide new information to resolve issue.
Other questions: what surface looks like - # craters, thickness of
dust surface.
Viewgraph: Objectives
General characterization: first look
- Size, shape, spin axis, craters, regolith
- highest resolution SSI images
- thermal properties from PPFI
Composition/Degree of Heterogeneity
- NIMS maps
- SSI multispectral (color) - good for chemical analysis
when combined with NIMS.
Environment Survey
- Particles & Fields
- Dust
- Extreme UV
(Expect Gaspra to have little effect on surroundings, but
not prudent to flyby without all eyes and ears open.)
Some asteroids expected to behave like very weak comets - degassing.
Gaspra is not believed to be one of these, but looking anyway.
Computer Animation: developed from actual computer file used to
control the spacecraft - not just a cartoon. In effect, is the
computer visualization of the commands and activities we told the
spacecraft to do, and as such, is a fairly valuable tool to see
how activities occur (as well as being pretty).
Will see a model of an asteroid - determined something about the
same shape as Phobos would be good. Deliberately didn't put in
much high resolution detail, as we don't know what it will look
like. Based on Phobos for geometry and shading model.
Animation:
Starts from perspective of S/C looking toward Gaspra, 8 hours
before closest approach.
Scan platform showing field of view. Closer, start 9 element
overlapping mosaic (35 minutes before closest approach) - 4
color images.
Final mosaic - moving rapidly with respect to background.
Zooms into model view at flyby - looking back at dark side.
Final model - Gaspra tumbling over LA basin for comparison
[Laughter from audience - it's pretty darned big - Jon]
Q&A:
Translate comment about telemetry not seeing as much as expected?
Ausman: didn't anticipate anything except cruise mode at 10 bps.
Not much experience with this data rate. Wished to change data
modes frequently to make sure data was being properly stored, etc.
Every time that happens, had a very short period in which the
ground could not keep up with the mode change - lost a few minutes
data. Complicates ability to characterize the system at this low
data rate.
How do you know camera worked?
Ausman: computer counts # of shutter commands sent to SSI. No
closed loop verification that camera actually saw what they were
told to.
Had High-Gain Antenna been working, could you have received
real-time images. Is there a sense of disappointment?
Johnson: Press is probably most disappointed. Had to tape info so
rapidly that even with HGA, wouldn't be able to return all data in
real time - had planned to tape and return it all. Would be
returning it now and have available tomorrow were HGA working.
Disappointing to wait for Xmas present, but getting to asteroid is
a major step - can wait for data.
O'Neil - would have had more OP-NAV images were HGA working.
Credit to OP-NAV people for getting a powerful amount of data
through multiple exposure techinque - 4 frames gave "absolutely
spectacular" performance. Could have been one of the most serious
limitations, but in the end, can't remember any better navigation
performance.
Chances of getting HGA back before 12/92 Earth encounter?
O'Neil: believe we have fully diagnosed problem with 3 pins
sticking to ribs. Comprehensive, increasingly aggressive plan.
Next step: 3rd cooling turn in mid-December - some prospect of
release. Better model suggests it will take several more cooling
turns to walk cooling pins out of their receptacles. This is good
news: it suggests we are getting the antenna cold enough, it's a
matter of more time. More aggressive actions being looked at. Can
take all the way to Jupiter and do probe mission without HGA.
Don't think will have to take significant risks to deploy HGA -
expected sometime in 1992.
Rotation cycle Q?
O'Neil: did take pictures to show full rotation cycle ~ 7 hours
before approach.
How long to return mono pictures at 10 bps?
O'Neil: not planned. 80 hours at 40 bps using 70-meter antenna.
Unlikely to get continuous 80 hours - takes longer. 3 weeks for
first OP-NAV image due to need to share with other projects.
Possible to revisit Gaspra with a later robotic probe to see
changes? Worthwhile compared to visiting other asteroids? Human
explorers in more distant future?
Johnson: discussions in scientific community on what makes sense.
Today is first segment of policy: flybys by spacecraft going other
places, providing reconnasiscence data. Would like to flyby
several different types (possible with CRAF/Cassini), evaluate,
and design a single mission to multiple asteroids, possibly with
rendezvous. At the moment, most would suggest getting different
types rather than returning to the same one. Don't expect
processes which would cause great changes over period of times of
years. Won't have seen all of Gaspra - far side at very low
resoution. But on balance, better to do several different types,
then visit & rendezvous with several different types.
Manned exploration - first may be Earth-crossers. Relatively easy
to get to energy-wise (some easier than the Moon). Considered as
possible targets in a general exploratory program in the past.
Effect of Gaspra encounter on upcoming proposed Ida encounter?
Johnson: If some data is returned before Ida decision, will affect
decision (e.g. why it's important to do other types of things).
Critical issue is timing - programmatic issue.
O'Neil: decision will be made on July 1, 1992. In first half of
'92, will be examining factors affecting it - tour to fly at
Jupiter, propellant cost (35 kg ~= two satellite encounters at
Jupiter). May or may not have Gaspra data in hand.
Rumor that White House wants Gaspra pictures released just before
Election day for political reasons?
O'Neil: White House is not in contact on this subject; we know
nothing of such an interest.
Did chart say 136 shutter clicks?
Ausman: 136 commands issued to SSI at that point.
But you were planning on 150 images?
Ausman: That's correct. The point at which that measurement was
taken was prior to the final image data taken.
Third cooling turn coming up in mid-December. This is the soonest
you could return data is if it works. If not, when can data be
returned?
O'Neil: At latest, during the few weeks before 12/8/92 Earth
encounter. Because of outstanding navigation accuracy, feasibility
of returning a single frame earlier over low-rate channel (during
November) is being assessed - very speculative right now. OP-NAV
data lets a more precise assessment of which part of mosaic Gaspra
would be in.
What do you expect to find that would make exploration of more
asteroids worthwhile?
Johnson: Gaspra belongs to one of biggest asteroid families - in
effect getting data on hundreds of similar asteroids. Fundamental
strategy to flyby other types and compare them - we know they're
not all the same.
(dropout) explain what penalty means?
Johnson: expensive in terms of propellant to encounter asteroids.
Were lucky to find a couple where very little extra had to be
expended to set up encounters.
What does composition of asteroids mean? Why is it important to
study asteroids?
Johnson: desire to understand how solar system formed, how
asteroids came to be composed the way they are. Fundamental
scientific questions - where we came from, where solar system came
from. Related an anecdote of an older scientist's feeling on his
first being allowed to touch a meteorite as something holy,
unchanged since formation of solar system.
--
Jon Leech (leech@cs.unc.edu) __@/
"We were driving along, minding our own business, when there was a
sudden flash of blue light which blotted out the stars. I thought it
was a nuclear bomb going off and despaired for my career." - Keith Hughes
|
| 560.511 | RE 560.510 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Oct 30 1991 11:42 | 113 |
| Article: 36903
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space
Subject: Re: Notes from Galileo Asteroid Flyby Briefing 10/29
Date: 30 Oct 91 10:35:03 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Just a couple of added comments and minor corrections.......
In article <7190@borg.cs.unc.edu>, leech@mahler.cs.unc.edu writes...
>
> Gailileo encountered Gaspra at 2:37 PST time, within 1000 mi.
> Takes 27 minutes to signal, so signal received at 3PM. Been in
One-way light time was actually 23 minutes. Even though Galileo's closest
approach was at 2:37PM, we had to wait until 3PM to know that everything
was normal and that the Gaspra sequence executed perfectly.
> Viewgraph: Galileo status. Real-time telemetry confirms sequence
> was done. Takes nearly 2 hours to go through full telemetry
> commutation table [what's a commutation table? - Jon] -> not much
> more than 3 opportunities to see a single measurement at lowest
> level.
The word is decommutation table. It just means certain portions of the
telemetry data is being looked at in real-time as it is being received
from the spacecraft. A spot check of the data if you will.
> Telemetry measurements:
>
> Time Predicted Actual
All times are Earth Receive Time (ERT) in PST. Remember, Gaspra
closest approach occured at 1500 ERT.
>
> 1506 Tape position
> Track 3, Tic 5902 Track 3, tic 5845
> Within normal variation.
>
> 1505 S/C power margin
> 87 watts 87 watts
>
> 1416 AACS command count (# slew commands)
> 8397 8397
> Received as planned.
>
> 1416 Scan platform position
> 243.3;-20.5 243.3;-20.5
The scan platform position are in RA and DEC.
>
> Shutter count change
> 1429 136 136
These are the number of shutter commands sent from the CDS (Galileo's main
computer) to the SSI (camera). A memory readout of the SSI will confirm
that the SSI executed the commands.
>
> Picture: OP-NAV image (OPNAV 5, 8 days out). Gaspra and stars are
> blurred lines where platform was repositioned.
>
The optical navigation images of Gaspra were taken as multiple exposures.
Since at this distance Gaspra still appears as a point and there was
movement of the scan platform, the Gaspra image appeared as a squiggly line.
The stars in the background also appeared as squiggly lines, all with the
same shape as shown before (a very rough approximation):
---
\
|
-|
/
|
|
--/
|
|
(---------
|
|
|
\---
> Viewgraph: Objectives
>
> General characterization: first look
>
> - Size, shape, spin axis, craters, regolith
> - highest resolution SSI images
> - thermal properties from PPFI
^^^^
PPR, the Photopolarimeter Radiometer.
> Computer Animation:
> Will see a model of an asteroid - determined something about the
> same shape as Phobos would be good. Deliberately didn't put in
> much high resolution detail, as we don't know what it will look
> like. Based on Phobos for geometry and shading model.
With the texture of Miranda thrown in as well.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.512 | Updates - October 30-31 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Oct 31 1991 18:26 | 114 |
| Article: 17947
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/30/91
Date: 31 Oct 91 00:24:33 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 30, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, Galileo completed the GASPRA encounter sequence. All the
Galileo instruments collected data except the Heavy Ion Counter (HIC), as
planned. All the encounter data is stored on the tape recorder (DMS) and will
be returned after the HGA (High Gain Antenna) is opened or via the LGA (Low
Gain Antenna) when Galileo is near Earth in late 1992.
Several hours after the encounter a sequence planned imaging instrument
(SSI) memory readout (MRO) was performed. The MRO confirmed that the planned
150 images were shuttered by the SSI.
Today, the photopolarimeter (PPR), Plasma Science (PLS) and NIMS (Near
Infrared Mapping Spectrometer) instruments were turned off as planned.
Tomorrow, the EE-4 (Earth-Earth 4) sequence memory load is
scheduled to be sent to the spacecraft.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
Article: 17959
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 10/30/91
Date: 31 Oct 91 05:10:17 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
October 30, 1991
The Galileo spacecraft is operating normally, in the dual-
spin mode, transmitting coded telemetry at 10 bits per second.
Yesterday Galileo successfully completed the first
spacecraft encounter with an asteroid, flying 1,600 kilometers
(1,000 miles) from the 10-by-18-kilometer (6-by-11-mile) asteroid
Gaspra and recording 150 images and many other scientific
measurements. Spacecraft telemetry sent during and after the
encounter confirmed that all the planned operations were
performed. Because the high-gain antenna is still not deployed,
the data will remain on the tape recorder until some time in 1992.
Four optical navigation images, exposed from September 6 to
October 21 and played back in small pieces over many days, helped
the flight team design two small trajectory correction maneuvers
which brought the spacecraft precisely into the desired flight
path near the asteroid.
The spacecraft is now about 412 million kilometers or 256
million miles from Earth. The speed in orbit is 15.7 kilometers
per second (35,076 miles per hour).
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
Article: 17968
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 10/31/91
Date: 31 Oct 91 22:37:46 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 31, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Today, the EE-4 (Earth-Earth 4) sequence memory load will be sent to the
spacecraft. This sequence controls spacecraft activities from November 4 to
December 4.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.513 | Updates - October 31-November 1 | JVERNE::KLAES | All the Universe, or nothing! | Sun Nov 03 1991 17:53 | 166 |
| Article: 17997
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 10/31/91
Date: 1 Nov 91 08:05:10 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
October 25 - 31, 1991
SPACECRAFT
1. The Galileo Gaspra closest approach (1000 miles) occurred on October 29 at
22:37:00 (UTC). This was the first-ever spacecraft encounter with an asteroid.
All the Galileo science instruments collected data except the Heavy Ion Counter
(HIC), as planned. A total of 150 images were taken and 126 of those were
taken within an hour of closest approach. All data was stored on the tape
recorder (DMS) for subsequent playback when HGA (High Gain Antenna) is opened
or via the LGA (Low Gain Antenna) when Galileo is near Earth in late 1992.
Although the telemetry sample rate was low (10 bps) selected engineering
measurements enabled the flight team in real time to determine the spacecraft
was executing the encounter sequence. The selected measurements included tape
recorder position, scan platform position and mis-slew count, power consumption
and the number of commands sent to imaging instrument.
2. Consistent with the planned command loss timer strategy for the Gaspra
encounter, commands were sent to reset the command loss timer on October 25,
27, 28 and 29 and update the command loss timer from 72 hours to 264 hours
on October 30, shortly after the encounter.
3. A sequence controlled SITURN was performed on October 28 to set up the
Gaspra encounter attitude conditions. The 23-degree SITURN resulted in the
spacecraft going from an Earth-pointed attitude to a near Sun-pointed attitude
leading the Sun by about 3.1 degrees.
4. Commands were sent on October 28 to change the telemetry data rate from
40 bps to 10 bps. The lower data rate was selected to permit dual-site
telemetry coverage over DSS-14 (Goldstone 70 meter antenna) and DSS-43
(Canberra 70 meter antenna) for the Gaspra closest approach period.
5. Commands were also sent on October 28 to enable the plasma science (PLS)
system fault protection in preparation for instrument powering on October 29.
Additionally, commands were sent on October 28 to enable the star scanner
bright body fault protection for the Gaspra encounter; the bright body fault
protection was disabled on October 29 hours after the closest approach.
6. The NIMS (Near Infrared Mapping Spectrometer), PPR (Photopolarimeter
Radiometer) and PLS instruments were turned on via the stored sequence for the
Gaspra encounter; the NIMS was powered on October 25 and the PPR and PLS were
powered on October 29 just hours before the encounter. Proper power turn on
was verified via power and/or instrument temperature telemetry. After the
encounter on October 30, the three instruments were turned off via the stored
sequence, as planned.
7. Imaging instrument (SSI) memory readouts were performed on October 26, 28,
and 30 to verify the instrument's health and status. The MRO on October 30
confirmed the 150 image count planned for the encounter.
8. Cruise science memory readouts were performed for the MAG (Magnetometer)
and dust (DDS) instruments on October 29 and for the MAG, DDS and EUV (Extreme
Ultraviolet Spectrometer) on October 30.
9. The EE-4A (Earth-Earth 4A) sequence memory load was sent to spacecraft on
October 31. This sequence controls spacecraft activities from November 4 to
December 4. The time window between December 4 and December 20 is set aside
for the HGA cooling turn No. 3 activities. EE-4B sequence presently in design,
will run from December 20 to February 17, 1992.
10. The AC/DC bus imbalance measurements exhibited some fluctuation. The DC
measurement increased 1 DN and now reads 14.8 volts, the AC measurement dropped
2 DN and now reads 44 volts. All other power telemetry and subsystem telemetry
are normal.
11. The Spacecraft status as of end of day October 24 was as follows:
a) System Power Margin - 48 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Sun pointed; Sun Point Angle
- approximately 2.8 degrees (sun leading) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR and NIMS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 260 hours
TRAJECTORY
As of noon Thursday, October 31, 1991, the Galileo Spacecraft status was
as follows:
Distance from Earth 256,965,950 miles (2.75 AU)
Distance from Sun 205,100,410 miles (2.20 AU)
Heliocentric Speed 35,030 miles per hour
Distance from Gaspra 739,000 miles
Round Trip Light Time 45 minutes, 52 seconds
SPECIAL TOPICS
1. As of October 31, 1991, a total of 5954 real-time commands have been
transmitted to Galileo. Of these, 2018 have been pre-planned in the sequence
design and 3936 were not. In the past week, 70 real time commands were
transmitted and all were pre-planned. In addition, 1927 mini-sequence commands
have been transmitted since March 1991; (24 were pre-planned and 1903 were not)
and none were sent this week. Major commanding activities this week included
several commands to reset the command loss timer, switching the telemetry data
rate (40 bps -> 10 bps) enabling/disabling selected fault protection and
uplinking the EE-3 prime Gaspra encounter sequences.
2. During the execution of the Gaspra encounter sequence at 10 bps, several
engineering telemetry channels went into alarm precluding complete real-time
confirmation of sequence execution. A quick review of the CDS (Command Data
Subsystem) software revealed that when operating at 10 bps, commanded telemetry
mode changes cause reinitialization of engineering data frame which results in
overwriting data presently located in the engineering buffer with new header
and data, thus disrupting the engineering measurement decommutation process and
precluding full sampling of all the engineering measurements. Because of many
telemetry mode changes planned in the Gaspra encounter sequence, engineering
telemetry was often disrupted so only partial confirmation of sequence
operation was possible. However, even with the disruption, there was adequate
real time telemetry to conclude that the spacecraft was, indeed, executing the
sequence.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
Article: 17987
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/01/91
Date: 1 Nov 91 22:43:50 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 1, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps.
Yesterday, the EE-4A (Earth-Earth 4A) sequence memory load was
sent to spacecraft. Today and over the weekend, there are no
spacecraft activities planned; tracking coverage is scheduled each day
over DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | Everything should be as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | simple as possible, but no
|_____|/ |_|/ |_____|/ | simpler. --Albert Einstein
|
| 560.514 | Update - November 4 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Nov 05 1991 19:50 | 31 |
| Article: 18029
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/4/91
Date: 5 Nov 91 00:59:49 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 4, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps.
Today, the EE-4A (Earth-Earth 4A) stored sequence will go active.
This sequence controls spacecraft activities from November 4 to
December 4, 1991. Activities planned today include sending a real-time
command to reset the Command Loss Timer.
Tomorrow, an imaging instrument (SSI) memory readout will be
performed to verify the instrument's health.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.515 | Update - November 5 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Nov 06 1991 13:15 | 34 |
| Article: 18046
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/05/91
Date: 6 Nov 91 00:27:54 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 5, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps.
Today, an imaging instrument (SSI) memory readout was performed
to verify the instrument's health.
Tomorrow, a sequence of commands are scheduled to be sent:
a) To perform a SITURN (18 degrees) from near sun point to Earth
point.
b) To increase the telemetry rate from 10 bps to 40 bps.
c) To position the tape recorder (DMS) to a selected position for a
limited playback of Gaspra data.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.516 | Body of notes should say *40* bits per second | DECWIN::FISHER | RIP, Great Bird of the Galaxy | Wed Nov 06 1991 15:06 | 6 |
| Aviation Week says that they are considering returning a couple of the Gaspra
frames within the next couple weeks while they can still get 20 bits/second.
They think this may be reasonable because given the nav accuracy, they have a
pretty good idea which frames the asteroid will actually appear in.
Burns
|
| 560.517 | Update - November 6 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Nov 06 1991 17:12 | 32 |
| Article: 18074
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/06/91
Date: 7 Nov 91 01:19:01 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 6, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Yesterday, Galileo performed an 18-degree SITURN going from a
near sun-pointed attitude to Earth-pointed attitude. Subsequent to
the turn the telemetry data rate was increased from 10 bps to 40 bps.
Today, the tape recorder (DMS) tape was positioned near to the
predicted location for playback of selected Gaspra data. Later today,
another RPM (Retro Propulsion Module) 10-Newton thruster "flushing"
maintenance activity is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.518 | Updates - November 7-11 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Nov 12 1991 11:28 | 68 |
| Article: 18095
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/07/91
Date: 7 Nov 91 22:58:58 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 7, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Yesterday, commands were sent to move the tape recorder (DMS) to
the start position for selected GASPRA data playback.
Today, DMSMRO (tape recorder memory readout) activity will begin
over DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18097
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/11/91
Date: 12 Nov 91 00:26:27 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 11, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Today, a command will be sent to reset the Command Loss Timer to
264 hours, its planned value for this mission phase. Additionally,
memory readout activities are scheduled for the MAG (Magnetometer) and
Dust (DDS) instruments. An imaging instrument (SSI) memory readout
will also be performed to verify health status. More DMS MRO playback
activities are scheduled over DSS-43 (Canberra 70 meter antenna) for
today and tomorrow.
Late Saturday night at about 2230 PST, a brief data outage
occurred when DSS-43 experienced an azimuth controller power supply
failure. DSS43 rapidly identified the problem, replaced the failed
power supply and was back "on-the-air" in about 40 minutes. On
Sunday, after image processing, it is determined that no GASPRA image
data was lost as a result of the station problem because the failure
occured at a line location after the point of the GASPRA image.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.519 | Update - November 7 (#2) | MTWAIN::KLAES | All the Universe, or nothing! | Tue Nov 12 1991 17:11 | 121 |
| Article: 18141
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 11/07/91
Date: 8 Nov 91 05:08:50 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
November 1 - 7, 1991
SPACECRAFT
1. A command was sent on November 4 to reset the command loss timer to 264
hours, its planned value for this mission phase.
2. Another routine imaging instrument (SSI) memory readout was performed on
November 6 to verify the health of the SSI.
3. A series of Delayed Action Commands (DACs) were sent on November 4. The
commands cycled the gyro heaters on/off and configured the radio subsystem to
the two-way non-coherent mode. The four heater commands were executed by the
spacecraft on November 5 in preparation for gyro-controlled SITURN activities
later that day. Two of the three radio commands were executed on November 5 to
minimize the telemetry loss resulting from planned telemetry mode changes; the
last radio configuration command is scheduled for execution on November 15.
4. An 18-degree SITURN was performed on November 5 to orient the spacecraft
from a near sun-pointed attitude to Earth-pointed attitude. Subsequent to the
turn, the telemetry data rate was increased from 10 bps to 40 bps to support
limited tape recorder (DMS) playback of Gaspra data.
5. Another RPM (Retro Propulsion Module) 10-Newton thruster "flushing"
maintenance activity was performed on November 6. All the thrusters were
flushed during the exercise. The spacecraft performance throughout the activity
was normal.
6. A mini sequence was sent on November 6 which will perform several
DMSMRO (tape recorder memory readout) activities over the next week to
retrieve a single Gaspra image. In preparation for the activity,
commands were sent later on November 6, to position the tape recorder
(DMS) to the planned start position.
7. The AC/DC imbalance measurements exhibited some fluctuation. The
DC measurement changed 2 DN and now reads 15.2 volts; the AC
measurement changed 1 DN and now reads 43.8 volts. All other power
telemetry and subsystem telemetry are normal.
8. The Spacecraft status as of end of day November 7 was as follows:
a) System Power Margin - 50 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Earth pointed; Sun Point Angle
- approximately 18.1 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR and NIMS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 240 hours
TRAJECTORY
As of noon Thursday, November 7, 1991, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 264,027,740 miles (2.80 AU)
Distance from Sun 206,203,900 miles (2.21 AU)
Heliocentric Speed 34,720 miles per hour
Distance from Gaspra 660,257,460 miles
Round Trip Light Time 47 minutes, 8 seconds
SPECIAL TOPICS
1. As of November 7, 1991, a total of 5970 real-time commands have been
transmitted to Galileo since Launch. Of these, 2019 have been pre-planned
in the sequence design and 3951 were not. In the past week, 16 real time
commands were transmitted; one was pre-planned and 15 were unplanned. In
addition, 2275 mini-sequence commands have been transmitted since March 1991;
(24 were pre-planned and 2251 were not); 348 were sent this week. Major
commanding activities this week included several commands to reset the command
loss timer, switching the telemetry data rate (10 bps -> 40 bps), DACs turning
gyro heaters on/off and positioning DMS for Gaspra image playback.
2. A Project status briefing was held on November 5 concerning the 16
unexpected CDS (Command Data Subsystem) lock change events observed since
September 1990; unexpected lock changes have been observed at stations
14, 43, 61 and 63. In all instances, the spacecraft never received, processed
or issued an unwanted command; the spacecraft continues to respond properly to
planned commands. A thorough review by Flight Control Support Office and DSN
(Deep Space Network) personnel of all pertinent data was presented. Two
common conditions identified among the events were: the spacecraft was mostly
in two-way mode and the uplink signal strength was low (but still several db
above threshold). Furthermore, the data review confirmed that two of the
events were ground induced due to procedural errors. The cause for the
remaining events is still unknown, however, a spacecraft hardware failure
(open solder joint in the command detector power-on-reset electronics) has
been identified; although possible it is thought very unlikely. This failure
coupled with electrical noise could cause random lock change events. Another
possible cause identified was that when commanding the spacecraft at low signal
strength and at a low uplink frequency sweep rate, the spacecraft hardware may
generate spurious lock changes.
Project requested that a laboratory test be performed using the
appropriate RF receiver and CDU (Command Detector Unit) hardware to
characterize the command channel performance at low uplink signal
strength and sweep rates and any other pertinent operational condition.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.520 | Updates - November 8-12 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Nov 13 1991 13:25 | 58 |
| Article: 18164
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/08/91
Date: 8 Nov 91 22:36:22 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 8, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Late yesterday, the DMSMRO (tape recorder memory readout) playback
activity was initiated, as planned. Today, at about 1730 PST, the DMSMRO
activity will resume over DSS-43 (Canberra 70 meter antenna).
Over the weekend, DMSMROs are scheduled for both days over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18147
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/12/91
Date: 13 Nov 91 00:44:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 12, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday at about 1630 PST, commands were sent to reposition the tape
recorder (DMS) in preparation for today's DMS MRO (Memory Readout) activity.
Today, the next DMS MRO activity will be performed over DSS-43 (Canberra
70 meter antenna) and is scheduled to begin about 1645 PST.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.521 | Update - November 13 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Nov 15 1991 13:02 | 70 |
| Article: 18203
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/13/91
Date: 14 Nov 91 02:22:21 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
GALILEO STATUS REPORT
November 13, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
DMS MRO (tape recorder readout) activity over DSS-43 (Canberra
70 meter antenna) was completed earlier today around 0200 PST.
Today, there is no tracking coverage during the prime work shift.
However, DSS-43 coverage is available for DMS MRO activities tonight
scheduled to begin around 1845 PST.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18207
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Briefing Set For First Gaspra Image
Date: 14 Nov 91 01:25:44 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Paula Cleggett-Haleim
Headquarters, Washington, D.C. November 13, 1991
(Phone: 202/453-1549)
NOTE TO EDITORS: N91-79
GALILEO GASPRA MEDIA BRIEFING SET
The first close-up picture ever obtained of an asteroid will be
discussed and released to the news media at a Galileo news briefing
scheduled for 1 p.m. EST Thursday, Nov. 14, 1991. The briefing will
originate from NASA's Jet Propulsion Laboratory, Pasadena, Calif..
The picture was taken by the Galileo spacecraft as it approached
the asteroid Gaspra on Oct. 29 and was played back this week.
Participants in the briefing include Dr. Wesley T. Huntress,
Director of the Solar System Exploration Division; William J. O'Neil,
Galileo Project Manager; Dr. Torrence V. Johnson, Project Scientist;
Dr. Michael J. S. Belton, Imaging Team Leader; and Dr. Joseph Veverka,
Imaging Team member. They will describe the techniques used to capture
and transmit the image, discuss the asteroid and answer questions.
The briefing will be carried live on NASA Select television,
Satcom F2R, Transponder 13, C-band, 72 degrees west longitude,
frequency 3960 Mhz.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.522 | | DECWIN::FISHER | RIP, Great Bird of the Galaxy | Fri Nov 15 1991 14:14 | 5 |
| Anyone hear anything about the Gaspra picture? I presume the asteroid must have
actually been in the frame or they would not have called the press conference.
(AvWeek said they had a 90% confidence that it would be there)
Burns
|
| 560.523 | bang on!!!! | KAOFS::R_YURKIW | | Fri Nov 15 1991 14:46 | 2 |
| I saw a quick glance at it on CNN news this morning and it looked like
it filled the frame beautifully.
|
| 560.524 | I saw it too | ZENDIA::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Fri Nov 15 1991 16:14 | 4 |
| I saw the picture on CNN last night. It looked like they had cropped it
but there was good detail. You could see the "pixels" in the image.
Looks like they got some good pictures if we can just get them back
home. I did catch that the picture was from 10k miles out.
|
| 560.525 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Fri Nov 15 1991 17:32 | 8 |
| In all honesty, sending the pictures back kind of scares me.
Why are they going through all this effort, IF they believe that the
HFA will be open in less than one month?
I think the HGA issue is worse than NASA is admitting .....
Tony
|
| 560.526 | | DECWIN::FISHER | RIP, Great Bird of the Galaxy | Fri Nov 15 1991 19:18 | 6 |
| I think they are already admitting it is pretty bad. A few people have expressed
optimism that they will get it open, but no one is absolutely confident, and you
can be pretty sure they are working on contingency plans for 10baud data from
Jupiter.
Burns
|
| 560.527 | PR trip | TUCKER::BIRO | | Sat Nov 16 1991 15:45 | 6 |
| I think they just want some positive PR. I dont think they are
worried about anyother problems but getting good PR to keep their
bugget happy..
john
|
| 560.528 | | HELIX::MAIEWSKI | | Mon Nov 18 1991 01:07 | 7 |
| I don't really see where transmitting the picture has anything to do with the
HGA. It wasn't suppose to be involved in these pictures even if it was opened.
According to the original plan, they were going to play the tape during next
year's fly by when the low gain antenna can transmit at 1200 baud as they did
with the Venus data.
George
|
| 560.529 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Mon Nov 18 1991 11:39 | 21 |
| George,
The HGA has everything to do with this! You contention that "It wasn't
suppose to be involved in these pictures even if it was opened." is
totally false. They had to go through massive contortions to get
pointing data at 10-40 baud. They had planned something like, I seem
to recall 1-150 pictures for pointing. They had to make do with 3!
They could have beamed the pictures back in almost real time, instead,
they are waiting until Dec 1992! And, by hook or crook, they got one
picture back at 10-40 baud!
If the HGA is deployed, the next attempt will be within one month, it
will be trivial to transmit all the data in a short time. They will
not wait until Dec 92, that is the date ONLY if the HGA is not
deployed.
If they have ANY confidence in the December effort, why do you think
they transmited a picture at 10 baud?
Tony
|
| 560.530 | | PRAGMA::GRIFFIN | Dave Griffin | Mon Nov 18 1991 11:52 | 18 |
| > If they have ANY confidence in the December effort, why do you think
> they transmited a picture at 10 baud?
[I think this was covered in a previous reply...]
Because it is the only way to prove to the public that the encounter was
successful. JPL public relations *lives* on images.
Saying that it was a successful encounter and having having a photo to
show for it are vastly different things in the public relations (and therefore
budget/funding) world.
You are, of course, free to read any conspiracy theories into it you want.
- dave
Besides .. It was a nice picture!
|
| 560.531 | | CLOSUS::TAVARES | John -- Stay low, keep moving | Mon Nov 18 1991 12:50 | 10 |
| The picture of Gaspara was fantastic! It is shaped more like a river
rock, with a peculiar hook-like appendage; quite different from the
circular shape that I would expect. The resolution on the photo was
what made it so spectacular. The briefing official said that it was
like trying to take a picture of a specific house in San Franscisco
from the JPL lab in Pasadena. They did a great job.
As I understood it, they would try again in December to shake loose
the high gain antenna. I'm glad I can see the positive news on
Magellan to offset this major bummer.
|
| 560.532 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Mon Nov 18 1991 15:10 | 7 |
| re .530
Well, if you want to call suspicion of breaucrats, a conspiracy
theory, so be it. I just feel real bad about this mission right now
and I think the depth of the problem is being swept under the rug.
Tony
|
| 560.533 | | PRAGMA::GRIFFIN | Dave Griffin | Mon Nov 18 1991 15:32 | 49 |
| Re: .532
I don't understand what depth there is to the problem. Are you quibbling
over the probability of the HGA opening? All I've heard is that it is
at 50%, with some engineers on the optimisitic side, while there are others
who are not so optimistic about it ever opening.
This is the only area of concern that I know exists with this mission - are
to alluding that there are more problems with Galileo that aren't being
mentioned?
To me, if the HGA doesn't open - Galileo is a very expensive bust of a
project (both in dollars and human costs). If it does open, I would expect
that the mission would move up into the very optimistic range as far as
data return -- but there's nothing stopping it from being rammed by some
meteoroid and providing no data at all (or some other engineering malfunction,
equally devastating).
Do I really care what the HGA opening probabilities are? Not really. If
it is .5 as they claim - fine. If it is .8, I'd wish they'd say so, but I
understand that they would prefer to be conservative and not raise hopes
too high. If it is .1, then there isn't a lot anyone on this planet can
do about it and I would hope that they keep on trying to open it until
the RTGs run out or the antenna is destroyed trying. It's not like there's
another probe on the launch pad that isn't getting any attention because of
this problem (though I sure some resources are being diverted).
Regardless of the true probability of the HGA opening, combined with the
limited number of attempts to open it to date, it seems a bit premature to
write Galileo off
JPL knows they've got a few YEARS to solve this problem, and I'm not going
to fall into a camp demanding instant solutions -- I'm pretty patient when
it comes to these situations.
So I guess my question to you is: if the probability of the HGA opening is 0.1
or 0.05, are you advocating shutting down the Galileo project altogether and
moving on to something else? (i.e., no further expenditures on Galileo other
than picking up the Gaspra images when it flys by in a few months, or reduce
the data gathering to particles and fields only - no images).
- dave
[If you want to find a bunch of suspicious bureaucrats, look no further than
the Space Station project -- a vast resource drain which is already wreaking
immense havoc on the unmanned program and may ultimately kill of the manned
program in the process. Pork barrel city, with a healthy dash of NASA
institutional "survival at any cost" to boot. Well, its just my opinion... :-)]
|
| 560.534 | GALILEO Gaspra Post Encounter Press Briefing | MTWAIN::KLAES | All the Universe, or nothing! | Mon Nov 18 1991 18:20 | 520 |
| Date: 14 Nov 91 19:40:31 GMT
From: borg!cs.unc.edu!leech@mcnc.org (Jonathan Leech)
Subject: Notes from Galileo Gaspra Encounter Post Press Briefing
These are notes I typed in while watching the conference on NASA
SELECT. As before, I disclaim absolute accuracy in my transcript (hey,
*you* try typing at the rate these guys talk for 75 minutes :-) and I
can't provide further details. Contact the JPL PIO:
Jet Propulsion Laboratory
Public Information Office
California Institute of Technology
4800 Oak Grove Dr.
Pasadena, CA 91109
for more information. No, they *won't* provide the image in
digital form, but they'll probably be happy to send you a print. I
wouldn't be surprised if the digital data shows up on ames in a bit,
though.
Jon (leech@cs.unc.edu)
__@/
Galileo Gaspra Encounter Post Press Briefing
11/14/91 10:00 AM PST
Intro:
Bob MacMillan, PIO
Introduction. Team will report on a sample of acquired data.
Wesley Huntress, Director Solar System Exploration Division, NASA HQ
Here to participate in a momentous event, the kind for which NASA's
planetary program has become well known. First view of an object of a
type never before seen: main belt asteroid Gaspra, a small object 8-10
miles across. We've crossed the belt several times on the way to outer
planets, but never stopped to look at objects which comprise belt.
Galileo's flyby represents first of several that NASA will conduct
during missions that enter or cross belt. Gaileo may visit Ida during
second pass in 1993. CRAF and Cassini may also flyby asteroids. NASA is
planning a potential rendezvous mission with a different class of
asteroid, in earth approaching and crossing orbits. Why? Asteroids are
relatively primitive objects left over from planetary formation or early
solar nebula, as such could contain significant clues to planetary
formation and early solar system. Asteroids are almost certainly source
of meterorites. We'd like to establish the connection. Meteorites may be
small pieces broken off in collisions and injected into Earth-crossing
orbits. Larger fragments, up to 1/2 mi across, have struck Earth on
geological timescale. Want to understand statistics, how often this
occurs.
Image is tribute to Galileo team. Overcame major obstacle of furled HGA
[High Gain Antenna - Jon], carried out incredibly difficult navigation
task and achieved all scientific objectives set prior to launch. Bodes
well for remainder of mission.
Bill O'Neal, Galileo Project Manager
Presenting image a year ahead of when expected, made possible by
navigation team, flight team, DSN, and spacecraft. Virtually every other
current mission gave up time on Canberra antenna to allow recovering the
image.
Slide: Galileo at Asteroid Gaspra.
Between 35-29 minutes before closest approach, recorded 36 images in
order to build a single color image of Gaspra. Middle image in sequence
had field of view of 1/2 degree, frame size 125 km wide at Gaspra (10x
size of asteroid). Problem was not fitting Gaspra in frame, but finding
it. Uncertainty in location was ~300km, so had to take 3 frames across
to cover this uncertainty. Appoximately the same uncertainty out of the
trajectory plane,
Slide: Galileo observations.
so we took a 3x3 mosaic, each 4 frames (through 4 filters) to
reconstruct an image. Best resolution image was recorded between 16 and
9 minutes from closest approach. 3x closer -> 3x better resolution, but
more frames needed to assure capturing an image. More uncertainty at
this point, so final mosaic was constructed of 51 frames to reasonably
assure capture. Were prepared as late as day of encounter to send
hundreds of commands to adjust mosaic to adjust for any difference
between optical navigation estimate of where Galileo was headed and
where we'd aimed it. Difference was miniscule - about 5 km - so could
cancel those adjustments.
On Saturday before encounter, navigation delivered final solution which
said we were headed exactly where we wanted to be going, achieved Gaspra
position uncertainty of 99%. Was now reasonable to get back one frame
early, problem being to know which frame to return. Couldn't return high
res frame - would have to have 6 to have even 50% chance of one
containing Gaspra.
Slide: Color mosaic showing forecast and achieved position uncertainty.
But in color mosaic, achieved uncertainty (3x smaller than expected)
gave 95% probability Gaspra was in the central frame. So we proceeded to
play back the central frame. Original plan was to play back from top to
bottom in 120 line segments (800 line image), play back over 40 bps
engineering channel. Flight team got fancy, did testbed to condition the
record and hit image right spot on, got image back in first 3 tracks.
Subsequently were able to reposition tape, returned green filter and
also IR and violet filters. Will be some time (weeks) before
reconstructed into a color image. For now, have a black and white image
of Gaspra dead centered in frame. That's how we did it. Now will turn
over to Torrance Johnson to tell why we did it.
Torrance Johnson, Project Scientist
Slide: Gaspra Objectives
General characterization - "Firrst look"
Size, shape, spin, craters, regolith, etc.
highest resolution images - SSI
thermal properties - PPR
Composition / degree of hetereogeneity
NIMS maps
SSI multispectral (color)
Encironment survey
Particles and fields
Dust
EUV
Dust collector - part of international experiment run from Germany. Dr.
Everhard Brun (sp?) ran this. Problem: every time he says he wants to go
somewhere he'll get lots of data [e.g. lots of dust - Jon], everyone
else says that's not a good idea. Planned encounter to avoid
gravitational influence and any dust in vicinity. Checked anyway, read
out before and after. Result was negative - no small impacts were seen.
Rate during cruise has been 1 encounter/3 days, has remained constant in
belt.
Other report on NIMS, trying to get spectral, color, and high resolution
data. Didn't get back any NIMS data during this playback, but it was on
while image was being acquired. We have 10-12 spactra, 17 channels each,
which have been analyzed. This is a JPL experiment. Tantalizing results,
but don't have a big show and tell today. Field of view only fits twice
across asteroid in this dataset (higher resolution on tape), so not much
detail. But instrument is operating well, saw thermal emission and
variation of spectra even in low resolution images. Hope to get more
info on composition and variation of composition later.
Michael Belton -Imaging team leader
Congratulations and admiration for navigation and flight team. Pointing
and accuracy is unprecedented in NASA history. Were able to point at an
object we knew little about with accuracy comparble to pointing at a
large house in San Francisco from Pasadena. Also gratitude to
astronomers around the world who participated for years and told us
where Gaspra is.
Slide: SSI Asteroid Strategy
1 Global Multicolor coverage on approach
- Compositional heterogenetity
2 Maximum high resolution coverage at low sun angles and high phase
angles
- Surface structures
Looking for suitable shadows so could look at features and understand
processes of evolution.
Slide: Final Phase of Gaspra Imaging Sequence
Reoslution/pixel about 160 meters, fairly good but not as good as Viking
Phobos images. 150 pictures on tape recorder, 36 predicted to have
Gaspra in it. So far have received 3 pictures, also a remarkable
achievement. 3 weeks ago: 0. 2 weeks ago: 1.
Slide: Final High Resolution Mosaic
Already covered, pass to next slide.
Slide: Gaspra: 4-color Mosaic (3x3 array)
Slide: Gaspra Spectrum and SSI filters, showing passbands of
filters and overlaid spectrum of Gaspra.
We've returned green image first. Trying to illustrate that there's
already information from ground-based spectrum on chemical nature of
Gaspra.
Slide: first look from Wed of last week. 12 lines read out of where we
thought image was on the tape. First look shows lines were just were we
thought in middle of frame; immediately we knews that accuracy was
unprecedented - saw part of asteroid in these 12 lines.
Key to asteroids is diversity - some very primitive objects, some
fragments born from collisions. Another idea is that there may be
multiplicity. From first lines,could see craters, albedo features, and a
very deep depression - could possibly be a bifurcated object? Interest
went up, team gathered to look at images.
Image from Sunday morning: full Gaspra image, almost exactly centered
(center of gravity at pixel coord 400,400 in an 800^2 image).
[This was what we've been waiting for! - Jon]
Blown up version of same image. Very, very irregular, monolithic (12
lines just caught top of object - not a bifurcation, probably a shadow).
Kind of soft looking object, has embedded all sorts of features. Violet
image (not available yet) shows the features much more prominently.
Slide: upside down Gaspra image.
First thing we did was try to figure out what it looked like. First
thought it looked like a salamander crawling out of space, shark's head,
great interpanetary ghoul, project manager's fist. Finally, a scientist
from Hawaii pointed out that it looks like Pearl Harbor and surrounding
areas.
Did throw off cover of camera before encounter; problems from Earth-Moon
flyby have gone away, camera is operating perfectly normally and to
specs.
Joseph Veverka, Imaging Team
Gaspra about size of Oahu. Mike tried to convince you that Gaspra is
more interesting [laughter]. Will discuss first scientific results.
First slide: Gaspra again.
Ground-based astronomers could determine it was irregularly shaped and
rotated about every 7 hours in counterclockwise direction. Gaspra is
much more irregular than the model, which contains information about its
dramatic past history. Earth estimates of size were also a bit small.
Slide: overlaid distorted ellipsoid model.
Something major came off limb. Scale about 8 km across. Picture is of
something that's suffered a lot in its history.
Slide: multiple projections of grid model.
Shows what we think Gaspra looks like from different directions. Can see
two large missing chunks. Dimensions: about 20 x 12 x 11 km.
Slide: original Gaspra image.
Will discuss geology and try to infer what has happened since beginning.
First: shape is irregular, and as mentioned, there are large
indentations on the limb, and ridges which crisscross the object -
indicates it's a fragment of a parent object. Suspect it's the survivor
of a series of catastrophic collisions in the past.
See a lot of small craters, to limit of resolution. Bigger ones 1-2 km
in size. See craters down to 100-200m resolution image. Estimate one of
the larger craters requires impactor 100m in size at 5 km/sec.
Slide: Major depressions and indentations. Scale is large. One about 8.5
km, one 8.6 km, one 5.3 km across.
Slide: Major ridges. [Seem to track depressions - Jon]
Slide: craters.
Craters are sprinkled uniformly, range in size from 2km down to limit of
resolution.
What does this mean for geology? Overall shape does record catastrophic
impacts which broke up parent body.
Slide: how are facets made?
Two possibilities: single big impact or multiple smaller impacts.
Slide: Gaspra: History
- Gaspra is a collisional fragment of a larger parent body
- Shaped determined by past castropjhic collisions
- Population of small craters (0.3 - 2 km) accumulated since last
catastrophic event (300-500 My ago?)
This is not very long ago!
Slide: Collisional hsitory of Gaspra with timescale.
We don't know if it's heated and differentiated or not. Two paths:
undifferentiated and differentiated.
First path: 4GY ago, a ~100km body. Soon after (~100My?), collision
produced parent body. ~1.5 Gy ago, further collisions produced Gaspra.
Slide: Gaspra outline.
Gravity = 1/2000 Ge
Escape speed = 10 m/sec
Low gravity explains how it can remain irregular. Escape speed means
most fragments of collision will leave (throws an orange, says this is
escape speed of Gaspra). What's surprising is not the irregular shape,
but that topography is very subdued. Believe this is because some debris
doesn't leave, but remains behind to produce regolith.
Slide: Gaspra: Surface
Solid, bare rock covered by thin or thick regolith.
Slide:
Probably covered by regolith
- How deep?
Albedos
- Rather homogeneous
- Only small variations on this side of gaspra.
Slide: Albedo map.
Average surface about 20%, ~2x lunar surface. A few bright spots
going up to 30% (may indicate different chemical composition).
Best way to look at composition is color. Just beginning this process.
Slide: False color image, ratio of IR:green. There are color
differences. Main difference due to sunlight, but there are smaller
variations we're beginning to work on which may tell about mineralology
of surface.
Excited about much higher resolution image. In current image, are many
interesting features at limit of resolution that don't seem to be
craters or ridges. Image on tape at ~4x resolution, will be played back
next year.
Slide: showing comparision of current and best images.
Will be able to answer some of these questions with best images.
Leave with two thoughts: image next year will answer some questions.
Will allow another paragraph or page in history of Gaspra. This is just
the beginning: first picture of asteroid. Spacecraft will visit other
asteroids: Gailileo - Ida (1993), CRAF.
Q&A:
[Some of the attributions are incorrect - I wasn't clear on what Belton,
Huntress, and Veverka looked like and mixed them up some. My
apologies to them.]
Does NIMS data show anything about differentiation? Chunks of metal or
spread evenly? Are 3 pictures through different filters taken within an
instant of each other?
Johnson: NIMS data at this distance has very low spatial resolution,
just beginning to analyze. Can't answer first question yet, will use
this type of data. Intruiging that spectra aren't all the same, looking
to see what that might mean. Looking for variations in chemistry.
Higher-res spectral and spatial data will tell something about history:
heated or more primitive. Good that there are differences to study, but
data not of enough quality yet to answer these questions. Will require
deeper analysis, can't do in instant science mode.
Belton: images taken within seconds of each other, basically simultaneous.
Will you take us back to when first image was returned? What was mood of
team?
Belton: I was up at Palo Alto in a conference. Team members saw 12 line
image (last Wed. morning), told me what was in there, we just went
crazy. Collected team members and had a quick meeting. Enjoyment and
self-congratulations. Back on Sunday at 8:30 to see first picture.
O'Neal: was a bonus to see part of asteroid in 12 lines.
Johnson: word spread quickly - I was in Washington. Everybody's first
reaction was "WOW!". Was better than expected. Based on other pictures,
expectations were lower than reality. Hoped to see shape, maybe big
craters. Sharpness and quality were a big surprise, credit to camera
team.
Nothing surprised you much. Was this testimony to ground observations?
Johnson: As usual, we owe a great debt to ground-based observations.
Character always the same, know quite a bit statistically and globally.
What we're getting, and where surprises are, are in the details of what
object is like in an individual sense. Controversy over e.g. soil
characteristics, team members had different ideas what it would look
like. Generally surprised at sandblased look, expected more angles.
Most views of Gailileo since April are on disappointing side. Are
results a shot in the arm for Galileo team?
O'Neal: Yes. Looking forward to something much, much better.
You've been thinking about astertoids for decade, this is first photo of
one. How good a picture will you be able to get with time? What remains
to be learned?
Johnson: current dataset tells us pointing accuracy, quality of image &
NIMS data and strategy for exploring Gaspra was successful. Detailed
design, some observations depending on doing quite well with pointing.
Current data gives high confidence that remaining data on tape gives
much more information - more spectral bands, more instruments. Believe
we had a very successful encounter, will allow us to do an in-depth look
when data is returned. Specifically, last image.
Veverka: as clever as Earth-based observers have been, there are limits.
Image we have now has intruiging features at limit of resolution that
don't look like craters. Will be able to see better in a few months, may
learn about processes which make Gaspra look as it does today. But may
be surprised - indicates something strange has happened to this object.
[ didn't catch the question or part of the answer ]
Belton: no resolved image of asteroid before. Some planetary satellites
observed believed to be asteroids.
How sharp will best images be?
Belton: current 160 m/pixel, could improve by 2.5-3.5x. Could approach
60 m/pixel in final image. Remember that information content goes as
square of resolution, basically 1 order of magnitude improvement.
Could you elaborate on collisions? Have all taken place in asteroid
belt? Could Gaspra have bounced or ricocheted around in its early
history?
Veverka: difficult to say what happened in early solar system. In recent
times, it's been in the belt, all collisions have occured in current
orbit - lots of stuff in belt running into each other. Has been going
on, is going on. When you see something as jagged as Gaspra with
relatively fresh surface, proves collisions have been going on.
Guess what irregular activities seen on surface are? Walk through next
attempt to loosen antenna?
Veverka: things at limit of resolution look like ridges or depressions.
Reminiscent of "grooves" seen on Phobos (about same size as Gaspra).
Appear to be fractures left by an impact which didn't quite break up
Phobos. Guessing at similar on Gaspra, has a violent history.
O'Neal: need to temperature cycle antenna several more times. Cold-soak
in December, perhaps as many as three times over first 4-5 months of
1992. Good prospect of releasing ribs at end of that campaign.
Did this say anything about changing origin of asteroids? Could you
review gee-whiz numbers about transmission?
Johnson: Data we're getting now has to do with history of these objects.
Does not tell us anything new about origins. Most of what we know comes
from study of planets. Do have new information about what happened since
that time, how many large scale collisions happened, current belt
environment.
O'Neal: playback began last Thursday, 8 consecutive 10 hour tracks at
Canberra. Last will be tonight. Transferred segments of image about 120
lines at a time from tape recorder to central computer memory and then
read out through 40bps telemetry system (engineering rate). First test
image done Tuesday night (Nov. 5th). Tonight is last playback. After
getting green, IR, and violet images, one remaining.
Will you send any more images back early?
[laughter]
O'Neal: will lose 40bps capability next week, down to 10bps due to
increasing distance from Earth. Coming back towards Earth after Jan
11th. By mid-April, should return to 40bps. Will look at returning some
more of this data in late spring-early summer rather than waiting until
December. Optimistically, if HGA opens before then, will play it all
back.
Don't understand explanation of how long it took to send the one image
we saw. Explain in layman's terms, compare to time it would take to send
a comparable image from Jupiter?
O'Neal: 2 tracks at Canberra, about 20 hours of transmission time
required for that particular image. When HGA is open, will return image
in one minute, be it in asteroid belt or at Jupiter.
But how long would it take through OMNI antenna at Jupiter?
O'Neal: would be same amount of time at 40bps. In unlikely event of not
having HGA, we believe we can make enhancements to support 40bps through
low-gain antenna at Jupiter.
Decision point on Ida coming up soon. Do you anticipate case for or
against will be strengthened by what we see on ground?
Veverka: S asteroids, like people, are diverse objects. We know Ida is
different from ground-based observations. No matter what we learn about
Gaspra, will want to look at Ida. Gaspra makes us more excited about
wanting to look at Ida - 2 different S asteroids.
[ inaudible question ]
Veverka: subtle issue how much material stays behind. Best guess is 3-10
meters on Gaspra-sized object.
Johnson: people were disappointed with Gaspra, wanted a big asteroid -
had planned on Amphitrite (larger asteroid). We're reasonably certain
big asteroids have regolith, really small ones don't, were unsure about
Gaspra-sized objects.
What suggests regolith? You have 160 m resolution, talking about 3-10
meter regolith.
Belton: Evidence has to do with craters. Almost all craters have a very
subdued appearance. Easiest way to give this appearance in our
experience is deposits of material. A few places look like large blocks
that have been buried and are sticking out.
Johnson: Can get information from crater shapes: 1 km crater is ~100m
deep, smaller ones only a few m deep. Shape is affected by material at
scales of 10m. Apollo images were surprising: nobody anticipated
micrometeorites, looked sandblasted. Same process produced the soil.
Another important piece of information: thermal properties of materials.
Two instruments, NIMS and PPR, measure temperature at different
wavelengths. Hope to get information back from both sides
[Satellite transmission was cut off at this point and replaced by a test
pattern. I think whomever schedules SELECT should be more flexible about
keeping events of high interest like this on the air - Jon]
|
| 560.535 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Mon Nov 18 1991 18:41 | 34 |
| re .532
I know of no other problem as serious as the HGA. They talk somewhat
about an AC/DC bus imbalance, as if it is some kind of problem, but I
must freely admit that I don't understand.
I guess I am just concerened that the potential for openning the HGA is
quite a bit less than .5, almost like JPL has about given up on it.
They never talk about it in the weekly reports (I can understand them
not talking about it in the daily reports).
The biggest problem I have is a SEVERE disapointment. I have been
awaiting Galelio pictures for about 7 years now. I virtually met my
wife over Astronomy magizine looking at the Voyager pictures of
Jupiter.
What am I advocating? Well, I think I want less costly systems.
Systems that are cheap enough that they will not require 15 years
between encounters! Systems that are cheap enough that a back-up can
be provided for reasonable cost! Attention to science rather than
gold-plating. If you have ever heard of EOS, then you know what I mean
by gold plating.
Yes, I also like to think that I am relatively patient, but I also
believe that with each failure, in my mind, the chance to see beautiful
pictures from Jupiter is vastly reduced. Sure JPL has years, but I see
no reason to believe that time is something that can resolve this
problem. And there is no prospect of another mission like Galeio for
AT LEAST 10 more years ..... I don't even like to think about it,
patience has its limits .......
FWIW, I agree with you on the space station.
Tony
|
| 560.536 | Updates - November 14-15 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Nov 18 1991 20:24 | 105 |
| Article: 18313
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/14/91
Date: 15 Nov 91 03:25:05 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 14, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Yesterday's DMS MRO (tape recorder readout) activity over DSS-43
(Canberra 70 meter antenna) was completed as planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18270
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 11/15/91
Date: 15 Nov 91 22:51:54 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 15, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 40 bps.
Yesterday, the DMS MRO (tape recorder readout) activity was
completed as planned.
Later today around 1630 PST, commands are scheduled to change the
telemetry rate from coded 40 bps to 10 bps to maintain acceptable
communications performance margin in preparation for next week's
planned SITURN activity.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18314
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: First Gaspra Image Released
Date: 15 Nov 91 02:29:10 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Paula Cleggett-Haleim
Headquarters, Washington, D.C. November 14, 1991
(Phone: 202/453-1547)
Jim Wilson
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
RELEASE: 91-189
FIRST PHOTOGRAPH OF AN ASTEROID RELEASED BY NASA
Scientists from the Galileo project today released the world's
first close-up image of an asteroid, taken Oct. 29 by the Galileo
spacecraft some 34 minutes before it flew past the asteroid Gaspra at
a distance of 1,000 miles. At that time the spacecraft and the
asteroid were about 205 million miles from the sun and 255 million
miles from Earth.
The picture was taken through a green filter by the Galileo
spacecraft's imaging system at a range of about 10,000 miles from Gaspra.
The picture is one of about a dozen Galileo took of the asteroid.
The Galileo team expects to have the spacecraft transmit to Earth
next year all of the spacecraft's Gaspra observations. That
transmission also would include one picture taken at even closer
range, a group of pictures to be combined with this green-filter image
to make a color picture and other images and scientific data.
The Galileo project, whose primary mission is to explore the Jupiter
system in 1995-97, is managed for NASA's Office of Space Science and
Applications by the Jet Propulsion Laboratory, Pasadena, Calif.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.537 | GALILEO Antenna Fact Sheet | MTWAIN::KLAES | All the Universe, or nothing! | Mon Nov 18 1991 20:31 | 139 |
| Article: 18315
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Antenna Fact Sheet
Date: 15 Nov 91 02:32:00 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from NASA Headquarters.
GALILEO FACT SHEET
GALILEO ANTENNA RELEASE AND DEPLOYMENT PROGRAM
Early in December 1991, the Galileo flight team will resume a
planned program of activities with the Galileo spacecraft to free the stuck
ribs of the umbrella-like, high-gain antenna by cooling and shrinking the
antenna central tower.
This operation will be the third in a series of cooling exercises in
which the Galileo spacecraft turns away from the sun, cooling the entire
antenna by radiation to space behind the main spacecraft sunshade.
Since the antenna failed to deploy in April 1991, Galileo's engineers
have performed many tests and analyses and have learned a great deal.
They conclude that a flexible program of multiple activities, including
repeated cooling cycles, conceivably lasting deep into the mission, is the
best way to get the antenna deployed. They do not believe the antenna has
been damaged.
Previous cooling turns in July and August 1991 dropped the
temperature in the critical area by an estimated 360 degrees Fahrenheit
and reduced the length of the tower out to the sticking zone by an
estimated 0.070 inch. The ribs, believed bound in place by friction
between alignment pins and their receptacles, did not spring loose.
However, analysis suggests the pins may have "walked" toward freedom
during those cooling activities.
The December cooling exercise, intended to reach somewhat lower
temperatures, will begin with the shutting down of a number of electrical
elements in the upper part of the spacecraft. Other electrical equipment
in the spacecraft bus nearby will be turned off or have power reduced to cut
down the amount of electrical heating. After a week of pre-cooling, Galileo
will turn about 165 degrees away from the sun, far enough to shade the
entire antenna and tower. It will remain in this attitude for 50 hours and
then turn back.
During the antenna's sunless period, controllers will not be able to
collect telemetry information from the spacecraft. The transmitter will be
on low power, and the operating low-gain antenna will be faced away from Earth.
Immediately after the cooling turn, the Galileo team will measure the
rotating spacecraft's wobble angle to see whether the center of gravity has
shifted, indicating release of one or more ribs, and will methodically collect
and analyze other appropriate measurements. From mid-November to mid-
April 1992, the spacecraft will be so far from Earth that the low-gain
antenna will only deliver telemetry at 10 bits per second, the lowest rate.
Galileo will be at its greatest distance from the sun in the present
orbit on Jan. 11, 1992. Ten days later, Galileo will be at the maximum
distance from Earth. It will be lined up on the far side of the sun from
Earth on Jan. 22, making communication difficult. However, the project
team plans to command another cooling turn late in January.
Galileo's next cooling operation could be planned for late February,
and perhaps monthly thereafter until the ribs are released. The 40-bit
telemetry rate will return in mid-April, easing and speeding the process of
collecting spacecraft measurements.
A number of possibilities for bumping or shaking the 2-1/2- ton
spacecraft have been considered, from retracting and redeploying the
second low-gain antenna boom to increasing the spin rate to pulsing the
propulsion system thrusters back and forth.
However, cooling the spacecraft appears to be the most powerful and
least risky single method to free the ribs, especially in the light of the
"walking the pins free" hypothesis. Indeed, the engineering analysts
believe that repeated cold cycling is the key to freeing the pins, the ribs
and the antenna.
Once the ribs are confirmed to be free, engineers will test and then
start the two deployment motors once more to crank the antenna open. It
then will be fully checked out and placed in service.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18314
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: First Gaspra Image Released
Date: 15 Nov 91 02:29:10 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Paula Cleggett-Haleim
Headquarters, Washington, D.C. November 14, 1991
(Phone: 202/453-1547)
Jim Wilson
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
RELEASE: 91-189
FIRST PHOTOGRAPH OF AN ASTEROID RELEASED BY NASA
Scientists from the Galileo project today released the world's
first close-up image of an asteroid, taken Oct. 29 by the Galileo
spacecraft some 34 minutes before it flew past the asteroid Gaspra at
a distance of 1,000 miles. At that time the spacecraft and the
asteroid were about 205 million miles from the sun and 255 million
miles from Earth.
The picture was taken through a green filter by the Galileo
spacecraft's imaging system at a range of about 10,000 miles from Gaspra.
The picture is one of about a dozen Galileo took of the asteroid.
The Galileo team expects to have the spacecraft transmit to Earth
next year all of the spacecraft's Gaspra observations. That
transmission also would include one picture taken at even closer
range, a group of pictures to be combined with this green-filter image
to make a color picture and other images and scientific data.
The Galileo project, whose primary mission is to explore the Jupiter
system in 1995-97, is managed for NASA's Office of Space Science and
Applications by the Jet Propulsion Laboratory, Pasadena, Calif.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.538 | | HELIX::MAIEWSKI | | Wed Nov 20 1991 01:58 | 20 |
| Tony,
I shouldn't have said "original" plan. That's not what I meant, sorry. By
"original" I meant the plan as of last summer.
I disagree with your contention that playing back one or two pictures at low
baud rate indicates a downward change in the forecast for opening the HGA over
what we've been hearing for the last few months.
Since the problem started, they have been saying that the chances of success
for opening the antenna at all (I assume that means by the time they reach
Jupiter several years from now) is about 50%. They haven't actually said, but
they seem to imply that the chances of opening it over the next year are much
less.
Based on that they came up with the plan of playing the tape during the fly
by. I don't see how playing back a picture early means that their estimate of
50% chance of success by Jupiter, less by next year, has gone down.
George
|
| 560.539 | Galileo status 11/19/91 | PRAGMA::GRIFFIN | Dave Griffin | Thu Nov 21 1991 13:36 | 43 |
| PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109
GALILEO MISSION STATUS
November 19, 1991
The Galileo spacecraft is more than 442 million kilometers
(about 275 million miles) from Earth, and 334.5 million
kilometers from the Sun. Speed in orbit is 15.3 kilometers per
second or about 34,300 miles per hour. Round-trip communication
time has reached 49 minutes 16 seconds.
The spacecraft is operating normally in the dual-spin mode,
with the upper part of the craft spinning at 3.15 rpm and the
lower part despun and held fixed in direction. It is sending
coded telemetry at 10 bits per second over the low-gain antenna.
The Deep Space Network is not tracking Galileo today; next
tracking pass occurs Wednesday, November 20.
The Galileo project negotiated with other missions to change
its tracking coverage during the last two weeks so as to transmit
a close-up image of Gaspra, obtained on October 29 at a range of
16,200 kilometers (10,000 miles). That green-filter image was
transmitted early last week and released publicly November 14;
its transmittal, using the technique employed in transmitting the
optical navigation images before the Gaspra encounter, took three
tracking passes at 40 bits per second.
The three other versions of the same picture, taken with a
violet and two infrared filters, were transmitted more quickly on
succeeding days. The scientists will analyze and compare these
images to search for variations in Gaspra's surface composition.
The spacecraft is now too far from Earth to use the 40-bits-per-
second data rate.
Galileo's next major spacecraft activity, scheduled to begin
in early December, will resume the planned program to free the
high-gain antenna's ribs and get the antenna fully deployed and
in service.
|
| 560.540 | Update - November 21 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Nov 22 1991 15:37 | 48 |
| Article: 18349
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/21/91
Date: 21 Nov 91 23:17:53 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
GALILEO STATUS REPORT
November 21, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps.
Today, no spacecraft activities/DSN (Deep Space Network) tracking
coverage are scheduled.
Tomorrow, a stored sequence planned SITURN and memory readout
activities for the imaging instrument (SSI) and EUV (Extreme
Ultraviolet Spectrometer) instrument are scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18351
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Gaspra GIF Image Available at Ames
Date: 21 Nov 91 22:28:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
The Gaspra GIF image is now available via anonymous ftp at
ames.arc.nasa.gov. It is in the pub/SPACE/GIF directory as gaspra.gif.
The image was posted previously by David Nusbaum to sci.space, and is
a scanned in version of the the press release image.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.541 | Overcome with anxiety ,,, | ROGER::GAUDET | Because the Earth is 2/3 water | Fri Nov 22 1991 16:23 | 7 |
| .540> The Gaspra GIF image is now available via anonymous ftp at
.540> ames.arc.nasa.gov. It is in the pub/SPACE/GIF directory as gaspra.gif.
OK, I'll be the impatient one and ask ... anybody have this file on a
VMS or Ultrix system on the Enet?
...Roger...
|
| 560.542 | Updates - November 18-22 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Nov 22 1991 20:15 | 142 |
| Article: 18415
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/18/91
Date: 19 Nov 91 00:12:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 18, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
No spacecraft activities/DSN (Deep Space Network) tracking coverage are
scheduled for today and tomorrow. The next planned spacecraft activities
are scheduled for Wednesday over DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18423
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/22/91
Date: 22 Nov 91 21:10:42 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
November 15 - 21, 1991
SPACECRAFT
1. Commands were sent on November 15 to position the tape recorder (DMS) to
return the fourth Gaspra image; the infrared filter image was retrieved via
DMSMRO (tape recorder memory readout) activities on November 15 similar to the
earlier three images taken thru green, violet and red filters.
2. Commands were sent on November 15 to reconfigure the imaging instrument
(SSI) from the Gaspra encounter state to a benign cruise state. The commands
repositioned the filter wheel to green, switched out the data compressor
function, turned off the light flood and increased the frame rate from 8 2/3
seconds to 60 2/3 seconds. The SSI state was then verified via the stored
sequence planned SSI Memory Readout (MRO) on November 16.
3. Imaging instrument (SSI) routine memory readouts were completed on
November 16 and 20 to verify the health status of the SSI.
4. The telemetry data rate was reduced from 40 bps to 10 bps via commands
sent on November 15; the data rate reduction was necessary to maintain
acceptable telecommunications performance margin.
5. A NO-OP command was sent on November 20 to reset the command loss timer to
264 hours, its planned value for this mission phase.
6. Delayed Action Commands (DACs) were sent on November 20 to configure the
gyro heaters and gyro state in preparation for the stored sequence planned
SITURN on November 22; the five DACs are scheduled to be executed on
November 22.
7. The EPD (Energetic Particles Detector) instrument was positioned from
Sector 4 to Sector 0 (predicted least contamination location) on November 20
via the stored sequence and will be positioned back to Sector 4 on November 22.
This repositioning activity was built into the stored sequence during
development when it was thought TCM-13 (Trajectory Correction Maneuver 13) was
required; recently TCM-13 was cancelled.
8. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 3 DN and reads 15.1 volts; the AC measurement dropped
1 DN and reads 43.9 volts. All other power telemetry and subsystem telemetry
are normal.
9. The Spacecraft status as of end of day November 21 was as follows:
a) System Power Margin - 44 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Earth pointed; Sun Point Angle
- approximately 21.2 degrees (sun lagging) plus or minus 0.3 degree
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR and NIMS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 236 hours
GDS (Ground Data System):
1. A Ground Data System (GDS) test of the telemetry anomaly replay interface
with the German Space Operations Center (GSOC) was successfully completed
November 21 confirming that problems observed during previous testing had been
fixed. The interface will be used to quickly transfer telemetry data to JPL
for analysis if a Spacecraft anomaly occurs during a GSOC track in support of
Cruise Science operations.
TRAJECTORY
As of noon Thursday, November 21, 1991, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 276,582,240 miles (2.97 AU)
Distance from Sun 208,068,650 miles (2.22 AU)
Heliocentric Speed 34,200 miles per hour
Distance from Jupiter 666,476,370 miles
Round Trip Light Time 49 minutes, 6 seconds
SPECIAL TOPICS
1. As of November 21, 1991, a total of 5989 real-time commands have been
transmitted to Galileo since Launch. Of these, 2026 have been pre-planned in
the sequence design and 3963 were not. In the past week, 14 real time commands
were transmitted; six were pre-planned and 8 were unplanned. In addition, 2275
mini-sequence commands have been transmitted since March 1991; (24 were
pre-planned and 2251 were not); none were sent this week. Major commanding
activities this week included a command to reset the command loss timer, DMS
tape positioning commands, DACs in preparation for the SITURN, SSI state
reconfiguration and telemetry data rate commands.
2. The seventh HGA (High Gain Antenna) anomaly review board meeting will be
held at JPL on November 22. The meeting will focus on the status "walking"
pin analyses, modal testing, the third cooling turn activities and near term
plans.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.543 | Gaspra image | PRAGMA::GRIFFIN | Dave Griffin | Sun Nov 24 1991 21:43 | 6 |
| I was about to fetch the Gaspra image, when I checked my mail to see
the Mike Campenella already had snarfed it!
It's available from: pragma::public:[nasa]gal_gaspra_1.gif
- dave
|
| 560.544 | To quote Mr. Spock from "Star Trek II: The Wrath Of Khan" | ROGER::GAUDET | Because the Earth is 2/3 water | Mon Nov 25 1991 14:13 | 6 |
| (referring to planetoid Regula One) "... essentially a great rock in space."
Nice picture, albeit a darn small one. Great technical job in locating such a
small object in the vastness of space, however!
...Roger...
|
| 560.545 | Updates - November 25-26 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Nov 27 1991 13:44 | 95 |
| Article: 18543
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/25/91
Date: 26 Nov 91 05:36:47 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 25 ,1991
The Galileo spacecraft is operating in the dual-spin mode and
transmitting coded telemetry at 10 bps. Sometime between our last
track on Wednesday, November 20th, and initial acquisition on Friday,
November 22nd, another critical controller 2A POR (Power On Reset)
telemetry indication occurred. The telemetry signature was identical
to the previous 12 occurrences of this event. Commands will be sent
on Monday to reset the telemetry indicator.
Yesterday the MAG (Magnetometer) and Dust (DDS) memory readout over
DSS-14 (Goldstone 70 meter antenna) were completed as planned.
In addition to the CRC 2A reset commands, the Command Loss Timer
reset and a SSI (Solid State Imagine) instrument health memory readout
are planned over DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18566
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/26/91
Date: 27 Nov 91 00:18:24 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 26, 1991
The Galileo spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps.
Yesterday, the despun critical controller 2A POR (Power On Reset)
telemetry indication was reset verifying that the telemetry indication
was due to a spurious transient signal. The CDS (Command Data
Subsystem) has now experienced 13 such spurious events since February
24, 1990. Additionally, the Command Loss Timer was reset as planned
and an imaging instrument (SSI) memory readout was completed to verify
SSI health.
Tomorrow a routine 10-Newton thruster flushing maintenance
activity is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
Article: 18587
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Another Gaspra Image
Date: 27 Nov 91 09:49:10 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
I've placed another Gaspra image at the Ames site. Thanks to Phil
Stooke who took the time to scan in the image and convert it to PDS
format. This image was also scanned from a public released image of
Gaspra, but has a better pixel resolution than the previous Gaspra
image placed at Ames. The image can be retrieved via anonymous ftp at
ames.arc.nasa.gov as:
/pub/SPACE/VICAR/gaspra.img (PDS format)
or
/pub/SPACE/GIF/gaspra1.gif (GIF format)
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.546 | Gaspra image #1.5 | PRAGMA::GRIFFIN | Dave Griffin | Mon Dec 02 1991 17:12 | 9 |
| The image mentioned in .545 is available as:
pragma::public:[nasa]gal_gaspra_2.gif
It's just a zoomed-in version of gal_gaspra_1.gif. I'll have the PDS format
available for a few days if anyone uses that -- I only keep them on Pragma
long enough to transfer to a PC disk. [Contact me via mail.]
- dave
|
| 560.547 | Update - November 27 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Dec 03 1991 12:58 | 32 |
| Article: 18602
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 11/27/91
Date: 28 Nov 91 03:32:52 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 27, 1991
The Galileo spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Today, a routine RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance activity is scheduled over DSS-43 (Canberra 70 meter
antenna).
No spacecraft activities/DSN (Deep Space Network) tracking coverage are
scheduled for November 28 and 29. Tracking over DSS-14 (Goldstone 70 meter
antenna) will resume on Saturday, November 30; no tracking coverage is
scheduled Sunday, December 1.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.548 | Update - December 2 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Dec 03 1991 15:36 | 40 |
| Article: 18647
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/02/91
Date: 3 Dec 91 01:35:11 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 2, 1991
The Galileo Spacecraft is operating in the dual-spin mode and
transmitting coded telemetry at 10 bps.
The routine RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance activity was accomplished over DSS-43 (Canberra
70 meter antenna) as planned.
No Spacecraft activities/DSN (Deep Space Network) tracking
coverage was scheduled for November 28 and 29. Tracking over DSS-14
(Goldstone 70 meter antenna) was resumed on Saturday, November 30; no
tracking coverage was scheduled Sunday, December 1.
Today, the routine SSI (Solid State Imaging) Instrument health
MRO (Memory Readout), tape recorder (DMS) maintenance and Command Loss
Timer reset are scheduled over DSS-14.
Tomorrow, EUV (Extreme Ultraviolet Spectrometer), DDS (Dust
Detector) and MAG (Magnetometer) instrument cruise science MRO are
planned over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 301-355 Telos | The two hardest things to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | handle in life are success
|_____|/ |_|/ |_____|/ | and failure.
|
| 560.549 | Update - December 3 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Dec 04 1991 13:37 | 33 |
| Article: 18677
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/03/91
Date: 4 Dec 91 06:10:24 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 3, 1991
The Galileo Spacecraft is operating in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, a command was sent to reset the critical controller 2A
POR (Power-On Reset) telemetry indication verifying that the anomaly
was due to a spurious transient signal similar to the previous 13 events.
Today, memory readouts will be performed for the EUV (Extreme
Ultraviolet Spectrometer), DDS (Dust Detector), and MAG
(Magnetometer)instruments over DSS-14 (Goldstone 70 meter antenna).
Tomorrow, the EE-4 (Earth-Earth 4) stored sequence ends.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3602 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
|
| 560.550 | Update - December 4 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Dec 05 1991 12:37 | 31 |
| Article: 18688
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/04/91
Date: 4 Dec 91 23:44:49 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
GALILEO STATUS REPORT
December 4, 1991
The Galileo Spacecraft is operating in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Today, the sequence memory load for cooling turn #3 is scheduled
to be transmitted over DSS-14 (Goldstone 70 meter antenna). The
pre-cool portion of the sequence will go active on December 6.
Commands will be sent to configure the downlink in support of cooling
turn #3 activities. Furthermore, in support of cooling turn #3
activities, commands will be sent to change selected attitude control
fault protection parameters.
Tomorrow, no spacecraft activities are planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3602 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
|
| 560.551 | Updates - December 4-6 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Dec 09 1991 18:52 | 298 |
| Article: 18775
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 12/04/91
Date: 8 Dec 91 11:06:25 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
December 4, 1991
The Galileo spacecraft is almost 461 million kilometers (about
286 million miles) from Earth, and 337 million kilometers from the
Sun. It will reach a maximum solar distance of 340 million kilometers
on January 11. Speed in orbit is currently more than 15 kilometers
per second (almost 34,000 mph). Round- trip communication time is 51
minutes 8 seconds.
The spacecraft is operating normally in the dual-spin mode, in
which the larger upper part revolves at 3.15 rpm and the lower part,
containing the scanning instruments, is oriented in a fixed direction.
Galileo is transmitting coded telemetry at 10 bits per second over
the low-gain antenna; the Deep Space Network is tracking and receiving
Galileo routinely several times per week. The spacecraft is conducting
scheduled maintenance operations and memory readouts, including cruise
science data gathered by the dust detector, magnetometer and
ultraviolet instrument.
A stored sequence containing this month's cooling exercise was
sent to the spacecraft today. Beginning this week, planned equipment
shutdowns will pre-cool the spacecraft bus adjacent to the base of the
high-gain antenna. On December 13, the sequence will have the
spacecraft turn so that the antenna points 165 degrees away from the
Sun and remains fully shaded for 50 hours. This is similar to the
cooling exercises performed in July and August, but with added
pre-cooling and greater solar distance. This operation is part of a
planned program to free the three stuck ribs of the high-gain antenna.
Repeated temperature cycles are believed to be the best means for
working the ribs free.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3602 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
Article: 18778
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/05/91
Date: 8 Dec 91 11:12:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 5, 1991
The Galileo Spacecraft is operating in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the EE-4A (Earth-Earth 4A) stored sequence ended, as planned.
The cooling turn #3 sequence was sent and will go active on December 6.
Cooling turn #3-related activities will be performed thru December 17.
Today, no spacecraft activities are planned.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3602 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
Article: 18780
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 12/05/91
Date: 8 Dec 91 12:17:18 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
November 22 - December 5, 1991
SPACECRAFT
1. A 20-degree SITURN was performed on November 22, to orient the spacecraft
from an Earth-pointed to a near sun-pointed attitude. The turn was
accomplished using the P-thrusters; spacecraft performance throughout the turn
was normal.
2. Cruise science memory readouts were performed for the EUV (Extreme
Ultraviolet Spectrometer) on November 22 and December 3; Dust (DDS) and MAG
(Magnetometer) instrument readouts were performed for both instruments on
November 24 and December 3.
3. Imaging instrument (SSI) memory readouts were performed on November 22, 25,
27 and December 2 to verify the health status of the SSI.
4. A NO-OP command was sent on November 25 and December 1 to reset the command
loss timer to 264 hours, its planned value for this mission phase.
5. Sometime between the end of DSN (Deep Space Network) track on November 20
and the initial acquisition on November 22, and again between DSN tracks on
November 27 and November 30 a CDS (Command Data Subsystem) critical controller
2A POR (Power On Reset) telemetry indication occurred. The observed telemetry
signatures were identical to the previous twelve occurrences of this event.
Due to the benign nature of this event, no immediate action was required.
Commands were sent the following Monday, November 25 and again on December 2 to
reset the spurious transient telemetry indication as done for the previous
occurrences.
6. Two more unexpected CDS lock change counts were observed over DSS-14
(Goldstone 70 meter antenna) on November 22. It was discovered that the lock
change counts resulted from a ground antenna control anomaly at DSS-14. The
spacecraft did not receive any commands as a result of the anomaly.
7. The periodic RPM (Retro Propulsion Module) 10-Newton thruster "flushing"
maintenance activity was performed on November 28; all 12 thrusters were
flushed during the exercise; spacecraft performance throughout the activity
was normal.
8. The Cooling Turn No. 3 sequence memory load was sent to the spacecraft on
December 4. The pre-cool portion of the sequence will go active on December 6;
the turn activity will begin on December 13.
9. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 2 DN and reads 15.1 volts; the AC measurement dropped
1 DN and reads 43.8 volts. All other power telemetry and subsystem telemetry
are normal.
10. The Spacecraft status as of end of day December 5 was as follows:
a) System Power Margin - 48 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Sun pointed; Sun Point Angle
- approximately 5.5 degrees (sun lagging) plus or
minus 0.3 degree
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered on except PLS, PPR and NIMS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 240 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Cooling Turn No. 3 stored sequence was approved by the Project for
transmission on December 3; the sequence was sent to the spacecraft on
December 4.
2. The EE-4B (Earth-Earth 4B) preliminary sequence and command generation
product was approved by the Project on December 4. This sequence controls
spacecraft activities from December 20, 1991 to February 27, 1992.
3. The EE-5 Cruise Plan product was approved by the Project on December 2.
This sequence controls spacecraft activities from March 9 to April 27, 1992.
GDS (Ground Data Systems):
1. Test activity associated with the GCF (Ground Communication Facility),
NOCC (Network Operations Control Center), and SPC (Signal Processing Center)
upgrades being implemented by the DSN (Deep Space Network) continued this week.
Galileo personnel participated in a Multimission Verification Test (MVT) of a
new version of the DSN Link Monitor Control (LMC) software (LMC OP-G). The
OP-G software provides no new capabilities to support Galileo. Galileo
regression testing was conducted to ensure that the baseline Monitor 5-9 and
Monitor 5-11 capabilities and interfaces were still operational for Galileo
support. Galileo testing with a new version of the DSN Tracking Station
Telemetry Processing Assembly (TPA) software was cancelled when problems were
found during Voyager testing.
TRAJECTORY
As of noon Thursday, December 5 1991, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 286,860,300 miles (3.07 AU)
Distance from Sun 209,479,160 miles (2.24 AU)
Heliocentric Speed 33,810 miles per hour
Distance from Jupiter 671,306,150 miles
Round Trip Light Time 51 minutes, 16 seconds
SPECIAL TOPICS
1. As of December 5, 1991, a total of 6052 real-time commands have been
transmitted to Galileo since Launch. Of these, 2073 have been pre-planned in
the sequence design and 3979 were not. In the past week, 54 real time commands
were transmitted; 46 were pre-planned and 8 were unplanned. In addition, 2275
mini-sequence commands have been transmitted since March 1991; (24 were
pre-planned and 2251 were not); none were sent this week. Major commanding
activities this week included commands to reset the command loss timer, commands
to reset the CDS POR 2A telemetry indications, update AACS (Attitude and
Articulation Control Subsystem) fault monitor parameters and radio
configuration commands.
2. The seventh HGA (High Gain Antenna) anomaly review board meeting was held
on November 22 at JPL. The latest "walking" pin analysis showed that alternate
maximum warming and maximum cooling of the tower provides the best prospects to
free the pins. The board endorsed the Project's plan to perform warming and
cooling turns.
3. The Operations Plan for the GSOC Operations Team was completed by the
German Space Operations Center (GSOC) and published in the Galileo Space Flight
Operations Plan (SFOP). The plan documents the team organization, personnel
roles, and operating mechanisms to be used by GSOC to provide Galileo Cruise
Science support after deployment of the High Gain Antenna.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3602 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
Article: 18782
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/06/91
Date: 8 Dec 91 11:24:58 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 6, 1991
The Galileo Spacecraft is operating in the dual-spin mode and transmitting
coded telemetry at 10 bps.
Today, the cooling turn #3 stored sequence will begin issuing commands to
pre-cool the spacecraft bus in preparation for the cooling turn on December 13;
several electrical loads will be turned off and the S-TWTA (high power
transmitter) will be set to low power. The pre-cool activity is programmed to
begin about 1430 PST over DSS-14 (Goldstone 70 meter antenna).
There are no spacecraft activities/DSN (Deep Space Network) tracking
coverage over the weekend.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3602 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
Article: 18781
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Color Image of Gaspra Released
Date: 8 Dec 91 11:20:07 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Paula Cleggett-Haleim
Headquarters, Washington, D.C. December 6, 1991
(Phone: 202/453-1549)
EDITORS NOTE: N91-84
COLOR IMAGE OF ASTEROID GASPRA AVAILABLE
A natural-color image and an enhanced-color image of the asteroid
Gaspra, taken by the Galileo spacecraft on Oct. 29, 1991, are being released
today through NASA's Audio Visual Branch. The pictures show the same
view of Gaspra as the black-and-white image released on Nov. 14, .
Media representatives may obtain copies of the pictures by calling
202/453-8373 or by inquiring at NASA Headquarters, 400 Maryland
Avenue, S.W., Washington, D.C., Room 6035.
[Note: Only photographs have been released, the image in digital format has
not been released yet. - Ron Baalke ]
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3602 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
|
| 560.552 | GALILEO images of Earth and 2001 parallels | MTWAIN::KLAES | All the Universe, or nothing! | Thu Dec 12 1991 18:04 | 100 |
| Article: 38469
From: yee@trident.arc.nasa.gov (Peter E. Yee)
Newsgroups: sci.space
Subject: Galileo images of Antarctica available
Date: 10 Dec 91 06:24:15 GMT
Sender: usenet@news.arc.nasa.gov
Organization: NASA Ames Research Center, Moffett Field, CA
Jeffrey Moersch of Cornell has made several images taken during
Galileo's 1990 Earth flyby available. His description follows. These
images may be found in the SPACE archives on ames.arc.nasa.gov
[128.102.18.3] and can be accessed via anonymous FTP in the
pub/SPACE/GIF directory. I do not have software to combine the
greyscale images into a single color image, but I would love to hear
from anyone who does.
-Peter Yee
yee@ames.arc.nasa.gov
ames!yee
File: antar2.*
This is a mosaic of 40 images (in red, green, and violet colors)
of Antarctica taken by Galileo several hours after it flew close to
the Earth on December 8, 1990. This is the first picture of the whole
Antarctic continent taken nearly at once from space, as distinct from
pictures pieced together from low orbit. Galileo was about 200,000
kilometers (125,000 miles) from Earth when the pictures were taken.
Features as small as 3 miles across can be seen.
The icy continent is surrounded by the dark blue of three
oceans: The Pacific to the right, the Indian to the top, and a piece
of the Atlantic to the lower left. Nearly the entire continent was
sunlit at this time of year, just two weeks before southern summer
solstice. The arc of dark spots extending from near the South Pole
(close to the center) toward the upper right is the Transantarctic
Mountain Range. To the right of the mountains is the vast Ross Ice
Shelf and the shelf's sharp border with the dark waters of the Ross
Sea. The thin blue line along Earth's limb marks our planet's
atmosphere.
Launched in October 1989 and bound ultimately for Jupiter,
Galileo received the first of its two gravity assists from its home
planet on December 8, 1990, and is proceeding on toward the asteroid
Gaspra.
The mosaic is composed of three files, each an 8-bit VICAR
image. To look at the mosaic on a 24-bit color display, place file
antar2.red in the red channel, file antar2.grn in the green channel,
and antar2.vio in the blue channel.
File: ross.*
This is a subset of the mosaic described above that shows only
the area around the Ross Ice Shelf, Ross Island, and the
Transantarctic Mountains. These images have been enhanced from the
true color mosaic to bring out the contrast of the mountains and the
blue of the glaciers. The largest glacier, seen in the left-center of
the image, is the Beardmore Glacier. Ross Island and McMurdo Station
are in the upper right corner.
moersch@astrosun.TN.CORNELL.EDU
Article: 38456
From: roberts@CMR.NCSL.NIST.GOV (John Roberts)
Newsgroups: sci.space
Subject: Galileo - 2001
Date: 9 Dec 91 22:43:11 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: National Institute of Standards and Technology
>From: higgins@fnalb.fnal.gov (Bill Higgins-- Beam Jockey)
>Newsgroups: sci.space
>Subject: HAL's birthday(was Re: Kubrick as NASA designer?)
>Date: 6 Dec 91 07:52:11 GMT
>Organization: Fermi National Accelerator Lab
>(Stray thought: could it be that the original mission of *Discovery*
>was to send an astronaut to open Galileo's high-gain antenna by hand
>in Jovian orbit?)
There are some strange parallels between the missions of Discovery (in
2001) and Galileo:
- Both are a first orbital mission to Jupiter (one fictional, one real-life).
- Both are (to some extent) nuclear powered.
- Both have major rotating and non-rotating components.
- Both are run by a computer.
- Both start complaining of a problem with the main communications
link to Earth while en route.
Once again, the keen insight of science fiction proves prophetic!
John Roberts
roberts@cmr.ncsl.nist.gov
|
| 560.553 | Updates - December 9-10 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Dec 12 1991 18:51 | 63 |
| Article: 18826
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/09/91
Date: 11 Dec 91 02:33:08 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 9, 1991
The Galileo Spacecraft is operating in the dual-spin mode and
transmitting coded telemetry at 10 bps.
The Cooling Turn #3 stored sequence issued commands to pre-cool
the spacecraft bus in preparation for the cooling turn on December 13,
several electrical loads were turned off and the S-TWTA (high power
transmitter) was set to low power.
No spacecraft activity/DSN (Deep Space Network) tracking coverage were
scheduled over the weekend. Today, no spacecraft activities are planned.
Tracking over DSS-14 (Goldstone 70 meter antenna) resumes. Tomorrow, no
spacecraft activities are planned. Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3602 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
Article: 18827
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/10/91
Date: 11 Dec 91 01:47:47 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 10, 1991
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps. The spacecraft bus continues to cool
in preparation for the cooling turn on December 13.
Today, no spacecraft activities are planned. Tracking is scheduled over
DSS-14 (Goldstone 70 meter antenna).
Tomorrow, no spacecraft activities are planned. Tracking is scheduled
over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3602 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
|
| 560.554 | Galileo Antarctica images available | PRAGMA::GRIFFIN | Dave Griffin | Thu Dec 12 1991 23:03 | 11 |
| The usual place...
pragma::public:[nasa]
gal_antarctica.gif is 1100x1100 (29 of 256 colors used)
gal_ross_ice.gif is 610x513 (45 of 256 colors used)
The raw image files (green, violet, and red are 4MB each and won't be
generally available).
- dave
|
| 560.555 | Update - December 11 | MTWAIN::KLAES | All the Universe, or nothing! | Fri Dec 13 1991 14:43 | 46 |
| Article: 18854
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/11/91
Date: 12 Dec 91 04:03:13 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
December 11, 1991
The Galileo spacecraft is nearly 468 million kilometers (291
million miles) from Earth, about 338 million kilometers from the Sun,
and almost 30 million kilometers from the asteroid Gaspra. Round-trip
communication time is 51 minutes 56 seconds; the Deep Space Net's
Goldstone 70-meter antenna station is providing tracking and telemetry
coverage this week.
The spacecraft is presently cooling down. It is in the dual-spin
mode, with the main body rotating at 3.15 rpm and the lower section
fixed in orientation, and is sending coded telemetry at 10 bits per
second. The transmitter has been switched to low power, and most of
the scientific instruments and some instrument heaters have been
switched off to pre-cool the area around the base of the antenna
central tower.
Friday afternoon Galileo will turn away from the Sun, reaching an
orientation 165 degrees off-Sun by about 4:40 p.m. PST. The high-gain
antenna will remain completely shaded from sunlight for about 50
hours, chilling and shrinking the central tower. This is the third in
the series of temperature cycles planned to free the antenna.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
|
| 560.556 | How Cold? | CLOSUS::J_BUTLER | L'audace, toujour l'audace! | Fri Dec 13 1991 17:41 | 6 |
| Does anyone know how cold they expect the tower to get or how much
shrinking will result?
Thanks!
John B.
|
| 560.557 | Updates - December 12-13 | MTWAIN::KLAES | All the Universe, or nothing! | Sat Dec 14 1991 18:39 | 178 |
| Article: 18883
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/12/91
Date: 13 Dec 91 04:43:24 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 12, 1991
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
The spacecraft bus continues to cool in preparation for the cooling turn
on December 13; the observed cooling profile is near predicted levels.
Today, no spacecraft activities are planned. Tracking over DSS-63 (Madrid
70 meter antenna) was completed earlier this morning.
Tomorrow, the spacecraft will execute the cooling turn to 165 degrees off
Sun over DSS-14 (Goldstone 70 meter antenna). The turn is scheduled to begin
about 1430 PST.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
Article: 18910
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/13/91
Date: 13 Dec 91 21:37:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
December 6 - 12, 1991
SPACECRAFT
1. A NO-OP command was sent on December 6 to reset the command loss timer to
264 hours, its planned value for this mission phase.
2. Commands were sent on December 6 to put an alert code time tag into the
AACS (Attitude and Articulation Control Subsystem) fixed telemetry. This
telemetry data provides information in determining the times that autonomous
HGA (High Gain Antenna) corrections occur between DSN (Deep Space Network)
tracks.
3. Commands were sent on December 6 to reconfigure the fault protection heater
state for the Plasma Wave Subsystem (PWS) in preparation for Cooling Turn
No. 3. These reconfigurations will preclude large thermal excursions on the
PWS search coil electronics in the event that safing is invoked while the
spacecraft is at cooling attitude.
4. The Cooling Turn No. 3 sequence memory load went active on December 6. The
pre-cool portion of the sequence will be completed on December 13. The turn
activity will begin on December 13.
5. Imaging Instrument (SSI) routine memory readouts were completed on
December 11 to verify the health status of the SSI.
6. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 6 DN and reads 15.8 volts; the AC measurement remained
unchanged and reads 43.8 volts. All other power telemetry and subsystem
telemetry are normal.
7. The Spacecraft status as of end of day December 12 was as follows:
a) System Power Margin - 37 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Sun pointed; Sun Point Angle
- approximately 7.2 degrees (sun lagging) plus or
minus 0.3 degree
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered off except SSI, EPD, and UVS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 120 hours
GDS (Ground Data Systems):
1. Project personnel are continuing to support testing of planned DSN system
upgrades. Last week Galileo data products generated during a preliminary DSN
Multimission Verification Test (MVT) of the Telemetry Processor Assembly (TPA)
upgrade were provided to the Project for analysis. Quick look analysis
indicated the test was not successful due to repeated data outages. A retest
will be required to demonstrate capabilities before it is used for Galileo
support.
TRAJECTORY
As of noon Thursday, December 12 1991, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 291,071,020 miles (3.13 AU)
Distance from Sun 210,014,720 miles (2.26 AU)
Heliocentric Speed 33,660 miles per hour
Distance from Jupiter 673,695,580 miles
Round Trip Light Time 52 minutes, 2 seconds
SPECIAL TOPICS
1. As of December 12, 1991, a total of 6072 real-time commands have been
transmitted to Galileo since Launch. Of these, 2075 have been pre-planned
in the sequence design and 3997 were not. In the past week, 20 real time
commands were transmitted; 2 were pre-planned and 18 were unplanned. In
addition, 2742 mini-sequence commands have been transmitted since March 1991;
(491 were pre-planned and 2251 were not); none were sent this week. Major
commanding activities this week included commands to reset the command loss
timer, commands to modify the AACS fixed telemetry, and fault protection
heater configuration commands.
2. The Cooling Turn No. 3 activities are scheduled from December 4 through
December 20, 1991. The spacecraft bus cool down period started on December 6
and will continue for a period of seven days. The spacecraft bus has cooled
down from 25 degrees C to 19 degrees C which is approximately 1.5 degrees
higher than the predicted value. The cooling turn will be performed on Friday,
December 13, and the spacecraft will be at the cooling attitude for
approximately 50 hours. The spacecraft turn back from the cooling attitude is
scheduled for December 16. Wobble ID and sun gate data collection is scheduled
for the December 17 through December 20 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
Article: 18925
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 12/13/91
Date: 14 Dec 91 03:06:03 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 13, 1991
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
The spacecraft bus temperature is near equilibrium in preparation for the
cooling turn today; the observed cooling profile is near predicted levels.
Today, the spacecraft will execute the cooling turn to 165 degrees off
sun over DSS-14 (Goldstone 70 meter antenna). The turn is scheduled to begin
about 1430 PST.
There is no spacecraft activity scheduled for December 14. Tracking is
scheduled over DSS-63 (Madrid 70 meter antenna) and DSS-14. The spacecraft
will begin to turn back from the cooling attitude at 1955 PST on December 15.
Tracking is scheduled over DSS-63 and DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
|
| 560.558 | Where is it ? | COLTRG::HENGSTMANN | I think i am | Mon Dec 16 1991 09:31 | 18 |
| Thanks many times for putting all these detailed reports here.
I for myself find this information very interesting.
But we are kind of completely disinformed over here so this is
why i would like to ask a more generic question or two.
Would it be possible to get some data about where on it's way
to / through the Ast.- Belt the spacecraft is right now ?
( something like a rough map maybe? )
Does it look like the fly-by close to GASPRA will work out
like planned ?
Thanks
Klaus
|
| 560.559 | RE 560.558 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Dec 16 1991 11:01 | 13 |
| The flyby of the GALILEO probe past the planetoid Gaspra took
place on October 29. The mission was quite a success, with several
images returned to Earth early. Gaspra looks somewhat like the
Martian moons Phobos and Deimos, which may be captured planetoids
themselves.
GALILEO is now about 35 million miles past Gaspra, headed for
a possible encounter with planetoid Ida in 1993, after its second
and final encounter with Earth in December of 1992. It will reach
Jupiter in December of 1995.
Larry
|
| 560.560 | | ELIS::GARSON | V+F = E+2 | Tue Dec 17 1991 05:15 | 27 |
| re .558
> Would it be possible to get some data about where on it's way
> to / through the Ast.- Belt the spacecraft is right now ?
In fact, it reaches aphelion - its greatest distance from the Sun - on
January 11 and then starts falling back in 'towards' the Sun. So it
only just made it out to the asteroid belt. However its orbit is planned
so that when it falls in to a distance from the Sun the same as Earth's,
we'll be there and Galileo will steal some of our momentum (the so-called
'gravity assist' - I hate that term) so that on its next orbit around the
Sun it can go out even further - all the way to Jupiter where it will
enter the Jovian system.
> ( something like a rough map maybe? )
Sigh...the limitations of a character cell terminal.
> Does it look like the fly-by close to GASPRA will work out like planned ?
If you have access to a workstation, I urge you to view the pictures
that have been released electronically. See previous notes (in this
topic?) for the location of the 'image' files and the viewer program.
The fly-by seemed to be extremely successful. Unfortunately owing to
the lack of availability of the High-Gain Antenna we'll have to wait
for the bulk of the data (including the closest pictures).
|
| 560.561 | Got the drift | COLTRG::HENGSTMANN | I think i am | Tue Dec 17 1991 08:38 | 12 |
|
Thanks !
I shall try to look up anything i can get access to.
Sorry for beeing out of date with the fly-by. But as You
can see, there is a delay in information which is not
easy to overcome. For example i tried to get some
information about METEOSAT out of ESOC here in Darmstadt
and was asked back if i was allowed to know about that
satellite ? ? ?
KLaus
|
| 560.562 | Update - December 16 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Dec 17 1991 12:13 | 43 |
| Article: 19000
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 12/16/91
Date: 17 Dec 91 03:31:44 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 16, 1991
The Galileo Spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps.
During the weekend, the Spacecraft remained at cooling attitude,
as planned, for approximately 50 hours. Subsequently, under stored
sequence control, the Spacecraft performed a sun acquisition to 5
degrees of sun point. The sun acquisition turn was completed on 15
December at 2140 PST.
Today, under stored sequence control, power state reconfiguration
is scheduled including turning on the DDS (Dust Detector), MAG
(Magnetometer), UVS (Ultraviolet Spectrometer), and EUV (Extreme
Ultraviolet Spectrometer) instruments.
Tomorrow, real-time commands will be sent to determine the
presence of bright body interference to the star scanner; if none is
detected, the star scanner shutter will be open by a subsequent
real-time command.
Additionally, a wobble ID is scheduled about 2230 PST and the
EE-4B (Earth-Earth 4B) sequence memory load is scheduled to be sent
over DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
|
| 560.563 | Sigh... | MTWAIN::KLAES | All the Universe, or nothing! | Tue Dec 17 1991 12:26 | 76 |
| Article: 1779
From: clarinews@clarinet.com
Newsgroups: clari.tw.space,clari.news.military,clari.news.aviation
Subject: Galileo antenna still stuck
Date: 16 Dec 91 21:56:47 GMT
PASADENA, Calif. (UPI) -- A weekend attempt to free a jammed
radio antenna crippling the $1.4 billion Galileo Jupiter probe was
unsuccessful, but officials held out hope Monday that additional
efforts next year will solve the problem.
The nuclear-powered Galileo, the most sophisticated
interplanetary probe ever built, was launched from the space shuttle
Atlantis on Oct. 18, 1989, kicking off a six-year voyage to Jupiter.
But on April 11, engineers at NASA's Jet Propulsion Laboratory
were dismayed to discover that commands to open the probe's
umbrella-like main antenna were not successful.
Detailed analysis indicated two or three of the 18 ribs making
up the dish-shaped antenna had failed to release from a central
support column. The 16-foot-wide ``high-gain'' antenna is crucial to
the success of Galileo's mission, but it is useless in the partially
deployed position.
Engineering studies indicate that if the antenna's central
column can be chilled enough in the deep cold of space, it will
contract slightly, freeing the stuck ribs.
On two earlier occasions, Galileo was oriented so that the
antenna was shaded from the warmth of the sun. Both attempts failed. A
third attempt this weekend also was unsuccessful, even though the
spacecraft's science instruments and other heat-producing electrical
systems were shut down to improve cooling.
``The preliminary indication here is that there was no rib
release,'' said Frank O'Donnell, a JPL spokesman. ``There are going to
be some more tests done over the next couple of days to really get the
full characterization.
``The thing that we're trying to emphasize is this is part of
an on-going effort to work with the antenna. This was not a do-or-die
effort.''
To reach Jupiter, Galileo was launched on a convoluted
trajectory requiring the probe to sail once past Venus and twice past
Earth for velocity-boosting gravity-assist flybys required to fling
the probe on toward its target.
The spacecraft zoomed past Venus and Earth in 1990, gaining
enough speed during the second flyby to reach the asteroid belt
between Mars and Jupiter. In January, Galileo will fall back into the
inner solar system for a second flyby of Earth on Dec. 8, 1992.
After that, Galileo finally will be going fast enough to head
out to Jupiter. If all goes well, the spacecraft will drop an
instrumented probe into Jupiter's stormy atmosphere before the
mothership slips into orbit around the giant planet in December 1995
for a planned 20-month tour.
But how much data is returned to Earth depends on the
high-gain antenna.
Galileo currently is sending data to Earth through a much
smaller antenna that is not capable of handling the huge flow of data
that will be generated by the probe's science instruments.
If the main antenna cannot be coaxed open, only a fraction of
the data scientists hoped to receive from Galileo will be radioed back
to Earth, a failure that would rival that of the optical defect
hobbling the Hubble Space Telescope.
But engineers at JPL are hopeful that additional cooling
cycles will cause the antenna's central column to contract enough to
free the stuck ribs, allowing the high-gain antenna to fully deploy.
|
| 560.564 | next attempt??? | KAOFS::R_YURKIW | | Tue Dec 17 1991 15:15 | 4 |
| Are they going to try to chill it down again before the end of january
before the probe start back in towards earth. This would seem to be the
farthest point that it will reach for at least two years when it is on
its way out to jupiter.
|
| 560.565 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Tue Dec 17 1991 15:51 | 13 |
| Maybe,
Certainly, knowing JPL, they will analyze the results of this 'cooling
turn' in excruciating detail. They will want to know if any further
'walking' occured, and if the results fit their theory.
My guess is that this will take at least until mid-January.
Will they be able to program another turn when the spacecraft is
furthest from the sun? Probably. They may want to try a heating turn
next tho, who knows?
Tony
|
| 560.566 | Smile, you're on Candid Camera | ROGER::GAUDET | Because the Earth is 2/3 water | Thu Dec 19 1991 14:08 | 18 |
| During a moment of random (and possibly ridiculously hap-hazard) thinking, I
began to wonder if it would be at all possible to actually "see" what's holding
up Galileo's antenna. All I've been reading about is the "theories" they have
based on telemetry data (I understand that at 200+ million miles distance there
isn't much more to go on). Assuming further attempts to open the antenna are
unsuccessful before the probe returns to Earth for the next "gravity assist,"
what are the chances, given current photographic, tracking and positioning
technologies, of snapping a very close and high resolution picture (or two or
three or ...) of the probe when it comes back? Would it be possible to get
close enough, using whatever craft might be available (shuttle, satellite,
special-purpose vehicle)? How about using some sort of telescopic assistance
(say, Hubble?) to zoom in?
You may fire at will. :-) But seriously, I'm curious as to whether such a
thing could be done, or why it's not reasonable (cost of mounting such an effort
doesn't count, although I'm sure it would be a major factor).
...Roger...
|
| 560.567 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Thu Dec 19 1991 14:38 | 7 |
| I think that might be a good thing to try. They could probably confirm which and
how many ribs are stuck, etc etc, even if they could not see the absolute details.
It also occurred to me that one might be able to warm something up with an
appropriately powered laser pulse. That might be a bit tricky, though!
Burns
|
| 560.568 | Hobbled Hubble Huddle | KACIE::DEUFEL | Daniel Allen Deufel | Thu Dec 19 1991 16:39 | 2 |
| Silly question...Does Hubble have the capability to do this?
|
| 560.569 | | PRAGMA::GRIFFIN | Dave Griffin | Thu Dec 19 1991 19:15 | 3 |
| No.
- dave
|
| 560.570 | | ELIS::GARSON | V+F = E+2 | Fri Dec 20 1991 05:04 | 25 |
| re .566
Not a bad idea.
A couple of things to bear in mind though...
When it goes past it will be travelling quite quickly relative to
current propulsion technology - otherwise we wouldn't have to use these
contorted 'solar system billiards' trajectories. This in itself doesn't
prevent us taking pictures. It just limits the amount of time when
Galileo will be in close range. (I don't have any figures though.)
Furthermore it suggests that it would be difficult to have anything
match velocity with Galileo so as to be able to take a series of 'still'
photos.
When it goes past (Dec '92?) there will still be some years of travel
before it reaches Jupiter. Some scientists will undoubtedly argue that
the chances are reasonable that further cooling attempts over that
period of time will free the ribs. Faced with that submission the
people who control the money might be reluctant to spend extra money
(how much?) next year that might be unnecessary. Of course if we're
going to do anything during the Earth flyby, that's just a risk to
take.
Anyone know how close Galileo comes to Earth on its next flyby?
|
| 560.571 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Fri Dec 20 1991 11:45 | 3 |
| Any news on if the antenna 'stepped' any more this cooling turn?
Tony
|
| 560.572 | Sorry, no can do | CARROL::LEPAGE | Dazed & Confused | Fri Dec 20 1991 13:58 | 49 |
| 560.573 | | HELIX::MAIEWSKI | | Fri Dec 20 1991 17:02 | 19 |
| While I was at DECUS, I talked to a guy who had just gone to work for JPL.
He said that they are still 50-50 on getting it open. Some days they feel very
confident then some days they feel less confident.
One interesting point he made was that at current rates the low gain antenna
can only pass data at 10 bits per second while out near Jupiter, but by using
better data compression and by improving the receivers on the ground they feel
they can improve that dramatically. He suggested numbers between 100 and 1000
bits per second.
Also when I asked why they just didn't crank the motor to see what happened,
he said they would only do conservative things now but would do more and more
risky things as they approached Jupiter.
He also mentioned that this problem does not affect the atmosphere probe
at all since the data rates of the probe are small enough to be handled by
the low gain antenna.
George
|
| 560.574 | Friday afternoon ramblings ... | ROGER::GAUDET | Because the Earth is 2/3 water | Fri Dec 20 1991 17:36 | 22 |
| Thanks to all for the detailed "expert" responses. Certainly there seems to be
many problems with taking pictures. I guess I was hoping for a sci-fi
cartoon-like rescue/repair scenario. How about this?
OK, here's what we do...we change Galileo's trajectory so that it's coming
straight for the Earth (I'm talking *straight* at us, not 550km off to one
side). Now, we plan to send up some major league photographic equipment on a
shuttle flight which just happens to coincide with Galileo's closest approach.
OK, now we point the HGA mast right at Earth. OK, now we start snapping
pictures as it approaches. OK, now just in the nick of time we fire Galileo's
thrusters and veer away from Earth, still picking up that gravity assist! The
pictures are relayed to Earth, they figure out what the heck is holding up the
antenna, and voila...it's fixed! Pretty slick, eh? :-)
OK, back to reality ... perhaps an even more fundamental question is in order:
Is there *anything* that could be done at the next Earth flyby which can take
advantage of its close proximity to Earth (besides a warming cycle near the
Sun)? The first thing that came to mind was the picture-taking scenario. Since
that seems to be somewhat "difficult" are there any other properties of the
flyby which can be put to good use?
...Roger...
|
| 560.575 | Updates - December 18-19 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Dec 30 1991 14:44 | 120 |
| Article: 5
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 12/18/91
Date: 19 Dec 91 02:13:32 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 18, 1991
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, real-time commands were sent to determine the presence of
bright body interference to the star scanner; none was detected and the star
scanner shutter was open by a subsequent real-time command. Additionally, a
wobble ID was performed to determine if there was any change to the Spacecraft
wobble subsequent to cooling turn #3. No change was observed. Also, the
EE-4B (Earth-Earth 4B) sequence memory load was sent over DSS-14 (Goldstone
70 meter antenna). The sequence goes active on December 19.
Today, real-time commands will be sent to reacquire celestial reference.
Tracking is scheduled over DSS-14.
Tomorrow, under sequence control, the TWNC will be commanded off. Track
is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
Article: 7
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 12/18/91
Date: 19 Dec 91 05:26:46 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
December 18, 1991
Sunday night, Galileo completed the third in the planned series
of temperature cycles designed to loosen three stuck ribs preventing
full deployment of the spacecraft high-gain antenna. On the basis of
two kinds of data obtained after the cooling cycle, the Galileo team
confirmed that, this time, as expected, no ribs were released.
The engineers believe that it will require more cooling and
warming cycles, shrinking and expanding the antenna central tower,
before the paired standoff pins work their way free, clearing the way
for deploying the umbrella-like antenna. The team plans a continuing
series of such actions, approximately every month or two in 1992 until
the ribs are free.
Otherwise, the Galileo spacecraft is exhibiting excellent health
and performance. It is in dual spin, with the upper body turning at
3.15 rpm while the lower part is despun and fixed in orientation. The
spacecraft is transmitting coded telemetry at 10 bits per second via
the low-gain antenna.
The spacecraft is currently 473 million kilometers (294 million
miles) from Earth, making the round-trip communication time 52 minutes
30 seconds. Its speed in orbit is 33,557 mph, and it is 339 million
kilometers from the Sun, nearly the maximum solar distance for this orbit.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
Article: 14
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 12/19/91
Date: 19 Dec 91 05:26:46 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 19, 1991
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, real-time commands were sent to reacquire celestial reference
subsequent to the cooling turn 3 exercise; celestial acquisition was achieved
without incident..
Today, the EE-4B (Earth-Earth 4B) sequence memory load went active.
Tomorrow, the routine RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance activity, and routine SSI (Solid State Imaging)
instrument health MRO (Memory Readout) are scheduled over DSS-14 (Goldstone
70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
|
| 560.576 | I wish they wouldn't do that... | DECWIN::FISHER | I *hate* questionnaires--Worf | Mon Dec 30 1991 17:17 | 17 |
| >full deployment of the spacecraft high-gain antenna. On the basis of
>two kinds of data obtained after the cooling cycle, the Galileo team
>confirmed that, this time, as expected, no ribs were released.
************
Gimme a break. While I fully admit that the Galileo mission folks were not
making outrageous predictions about it "working this time", neither did they
say anything like "We don't expect it to work this time".
I think NASA has a bad reputation for papering over bad news, and this is another
instance of it.
BTW, before you start quoting from previous updates, I *know* that they have said
they expect that it *may* take several tries to free it. It's the "spin" I'm
complaining about, not the facts.
Burns
|
| 560.577 | Updates - December 26-27 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Dec 30 1991 18:34 | 46 |
| Article: 25
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Status for 12/26/91 (Forwarded)
Date: 27 Dec 91 23:58:36 GMT
Sender: usenet@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
GALILEO STATUS REPORT
December 26, 1991
As of Monday, December 23, the Galileo Spacecraft was operating normally
in the dual-spin mode and transmitting coded telemetry at 10 bps.
Over the weekend, tracking coverage in support of the Radio Science
continued as planned.
On Monday, December 23, routine SSI (Solid State Imaging) instrument
health MRO (Memory Read-Out) were conducted as planned over DSS-14
(Goldstone 70 meter antenna).
There was no tracking coverage/spacecraft activity on December 24 and 25.
Tracking will resume on Thursday, December 26, with a planned SSI MRO scheduled
over DSS-14.
Article: 26
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Status for 12/27/91 (Forwarded)
Date: 28 Dec 91 00:05:04 GMT
Sender: usenet@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
GALILEO STATUS REPORT
December 27, 1991
The Galileo Spacecraft is operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps.
Tracking resumed on Thursday, December 26, the SSI (Solid State Imaging)
MRO (Memory Read-Out) over DSS-14 (Goldstone's 70 meter antenna) occurred
as planned.
Tracking will continue today and over the weekend as part of the Radio
Science scintillation experiment.
|
| 560.578 | Photos YES, if wanted ? | MAYDAY::ANDRADE | The sentinel (.)(.) | Tue Dec 31 1991 11:38 | 27 |
| Re.several
I don't see it as a very difficult problem, to get some pictures
of the Galileo Spacecraft. In order to verify the problem.
Although NASA may not bother, after all 2 or 3 ribs are STUCK,
the important thing is that they are stuck. Anything likelly to
release 2, will also do 3 or 4.
I mean meeting and getting a few pictures of the Gaspra asteroid
was a lot more difficult. And it was done, even with the reduced
Galileo capabilities.
How about this, sometime during the next year's shuttle flights
a small photographing sattelite is realeased. The shuttle often
has some payload margin to LEO. (Alternative is to use an already
launched satellite, if one exists at the correct altitude)
Then the satellite is maneuvared, so as to pass a couple kilometers
from Galileo when it comes around Earth for its gravity assist. And
takes the pictures then.
The costs here are either the construction of the micro-satellite
(launch is essentially free) or reduced propelant life time for an
existing satellite.
Gil
|
| 560.579 | Update - December 30 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Dec 31 1991 11:56 | 33 |
| Article: 32
From: johnson@kelvin.jpl.nasa.gov (Glenn S. Johnson)
Newsgroups: sci.space.news
Subject: Galileo Update - 12/30/91
Date: 31 Dec 91 04:34:13 GMT
Sender: usenet@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Forwarded from: William O'Neil, Galileo Project Manager
Galileo Spacecraft Daily Report
Monday
December 30, 1991
The Galileo Spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 10 bps.
Tracking was accomplished over the weekend as part of the Radio
Science scintillation experiment.
Today, memory readouts will be performed for the SSI, E UV, MAG,
and dust (DDS) instruments over DSS-14 (Goldstone 70 meter antenna).
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-42 (Madrid 34 meter antenna) as part of the Radio Science
scintillation experiment.
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
|
| 560.580 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Tue Dec 31 1991 15:15 | 10 |
| I think the problem is that tracking and magnification oppose each other in the
spectrum of tradeoffs. If you have a sat. close to Galileo, the relative motion
will be very high. Remember, Galileo is essentially coming in from infinity, so
it will be going at approx. Earth escape velocity. That means tracking would be
very difficult.
On the other hand, if the photo sat is far enough away to reduce the tracking
problem, you need a lot of magnification to get a useful image.
Burns
|
| 560.581 | Sorry, Gil... | CARROL::LEPAGE | Dazed & Confused | Tue Dec 31 1991 15:17 | 67 |
| Re:.578
> I don't see it as a very difficult problem, to get some pictures
> of the Galileo Spacecraft. In order to verify the problem.
Refer to my note 560.572 where I discuss this idea in more detail.
Bottom line: There is no way of taking useful pictures of Galileo at its
next Earth flyby.
> Although NASA may not bother, after all 2 or 3 ribs are STUCK,
> the important thing is that they are stuck. Anything likelly to
> release 2, will also do 3 or 4.
So?
> I mean meeting and getting a few pictures of the Gaspra asteroid
> was a lot more difficult. And it was done, even with the reduced
> Galileo capabilities.
Taking pictures of Gaspra is a LOT easier than getting pictures
of Galileo as it passes the Earth. Gaspra is a large body which was only
imaged with a maximum resolution of 50 meters. Galileo is a much smaller
body (about three orders of magnitude smaller) that will have to be imaged
at much higher resolution (again, about three orders of magnitude better)
in order to get some "useful" images. These higher requirements make taking
useful pictures of Galileo MUCH, MUCH more difficult than taking pictures
of Gaspra and may be beyond the current state of the art.
> How about this, sometime during the next year's shuttle flights
> a small photographing sattelite is realeased. The shuttle often
> has some payload margin to LEO. (Alternative is to use an already
> launched satellite, if one exists at the correct altitude)
First problem, there are no available slots for such a Space Shuttle
flight. It's booked solid. Second problem, even if there was a Shuttle
available, the hardware, mission planning, safety testing, etc. needed
to launch a satellite like this from the Shuttle would likely require more
time than is available. Third problem, even if there was a Shuttle available
and it made it up in time, there is no off-the-shelf satellite available that
can perform this sort of mission and it would take too long to modify an
existing one.
> Then the satellite is maneuvared, so as to pass a couple kilometers
> from Galileo when it comes around Earth for its gravity assist. And
> takes the pictures then.
Refer again to 560.572: It can't be done. To make matters all the
worse, a small satellite like this would have an even tougher time taking
a picture of the passing Galileo than I indicated in this note. That's because
Galileo will be passing by the Earth in a direction OPPOSITE that in which
most Earth satellites (like the Shuttle) travel around the Earth (i.e. Galileo
is in a retrograde hyperbolic escape trajectory while the Space Shuttle
circles the Earth in a prograde direction). That means that the relative
velocity between Galileo and our little photo-sat is 50% higher than I assumed
in 560.572 making the engineering challenges that much worse.
> The costs here are either the construction of the micro-satellite
> (launch is essentially free) or reduced propelant life time for an
> existing satellite.
Sorry, Gil, your plan could not be implemented in time at any cost,
never mind at any reasonable cost. In the end, it would be a lot cheaper
to launch a special comm sat to relay Galileo's data from Jupiter (and even
that would probably not be ready in time to help Galileo).
Drew
|
| 560.582 | | HELIX::MAIEWSKI | | Fri Jan 03 1992 12:38 | 21 |
| I agree with Drew and would like to add one point. Even if they did, through
some multi-billion dollar miracle get a photo of the probe, what good would
it do? So they would see 3 or 4 stuck ribs, big deal.
To be useful, they would have to get a picture taken from a few feet away
looking right at the ribs from the proper angle and it would probably have
to be magnified and illuminated to show the problem in detail.
To put it into perspective, say that you couldn't get the hood of your car
open. Then say that the mechanic flew past your car in an F-15 at Mach 1.5 at
about 5000 feet agl and snapped a picture. Would that help him figure out why
the hood wouldn't open? Heck no, he'd have to be standing in front of your auto
looking up at exactly the right angle, drop light in hand and he still might
not be able to see the problem.
The gap between the ribs and rib holder is suppose to be a fraction of an
inch and the problem might not even be visible to someone standing right next
to the antenna much less from a picture taken from miles away moving Mach 35 in
the opposite direction.
George
|
| 560.583 | Still think it would be neat if lasering it would help! :-) | DECWIN::FISHER | I *hate* questionnaires--Worf | Mon Jan 06 1992 14:23 | 4 |
| I tend to agree...however, it is frustrating to have the thing so close, but have
it not be helpful! Close in distance is not close in velocity, of course...
Burns
|
| 560.584 | Updates - December 31 to January 3 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Jan 06 1992 15:32 | 58 |
| Article: 35
From: JOHNSON@KELVIN.JPL.NASA.GOV (Glenn S. Johnson)
Newsgroups: sci.space.news
Subject: Galileo Update - 12/31/91
Date: 1 Jan 92 03:41:16 GMT
Sender: usenet@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
Galileo Update
December 31, 1991
The Galileo Spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 10 bps.
Yesterday, memory readouts were performed for the SSI, EUV, MAG,
and dust (DDS) instruments over DSS-14 (Goldstone 70 meter antenna).
Today, no spacecraft activity is scheduled. Tracking was completed
over DSS-42 (Canabera 34 meter antenna) as part of the Radio Science
scintillation experiment.
Tomorrow, no spacecraft is scheduled. Tracking will resume on
Thursday, January 2 over DSS-14.
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
Article: 38
From: JOHNSON@KELVIN.JPL.NASA.GOV (Glenn S. Johnson)
Newsgroups: sci.space.news
Subject: Galileo Update - 1/3/92
Date: 4 Jan 92 01:41:33 GMT
Sender: usenet
Organization: Jet Propulsion Laboratory
Forwarded from: William O'Neil, Galileo Project Manager
GALILEO UPDATE
3 January 1992
The Galileo Spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 10 bps.
There is no planned Spacecraft activity until Monday, January 6, 1992.
Frequent (near continuous) tracking is scheduled in support of the Radio
Science scintillation experiment.
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
|
| 560.585 | Update - January 6 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Jan 08 1992 19:16 | 41 |
| Article: 47
From: johnson@kelvin.jpl.nasa.gov (Glenn S. Johnson)
Newsgroups: sci.space.news
Subject: Galileo Update - 1/6/92
Date: 7 Jan 92 03:40:02 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
Galileo Spacecraft Daily Report
Monday
January 6, 1992
The Galileo Spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 10 bps. [bits per second *]
There was no planned Spacecraft activity over the weekend. Frequent
(near continuous) tracking was performed in support of the Radio Science
scintillation experiment.
Today, memory readouts will be performed for the EUV instrument over
DSS-14 (Goldstone 70 meter antenna). Additionally, real-time commands are
scheduled to modify the SSI fault protection for the upcoming thermal test.
Tomorrow, the SSI memory readout is scheduled along with the SSI thermal
test over DSS-14 and DSS-43 (Madrid 70 meter antenna).
[* Note: The 10 bps data rate is due to the use of the low gain omni
antenna and the great distance from Earth. The high-gain umbrella
antenna failed to completly deploy. There is still hope that
subsequent heating/cooling maneuveres will free the antenna prior to
Jupiter. (This note is in response to the question "bps isn't bits
per second, is it?") GSJ]
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
|
| 560.586 | Updates - January 7-8 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Jan 09 1992 13:13 | 98 |
| From: DECWRL::"usenet-space-news-request@ames.arc.nasa.gov" 8-JAN-1992
14:33:56.27
To: sci-space-news@ames.arc.nasa.gov
Subj: Galileo Updates - 1/7/92
Galileo Spacecraft Daily Report
Tuesday
January 7, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps (bits per second).
Yesterday, memory readouts were performed for the EUV instrument over
DSS-14 (Goldstone 70 meter antenna). Additionally, real-time commands were
sent to modify the SSI fault protection for the upcoming thermal test today.
Today, the SSI memory readout is scheduled along with the SSI thermal
test over DSS-14 and DSS-43 (Canberra 70 meter antenna).
Tomorrow, a routine RPM 10-N thruster "flushing" maintenance activity
is scheduled over DSS-14 along with the uplink of the sequence memory load
for warming turn #4.
[Note: The warming and cooling turns are hoped to free the stuck high gain
antenna. Several have been performed, several more are planned. When the
antenna completes deployment, the data rate will increase dramatically. There
will be several rates available, with a maximum of 134.4 Kb/s (kilo-bits per
second). As Galileo approaches Earth Encounter 2, high data rates using the
just the omni will be available. The recorded Gaspra images will be played
back when the high gain opens, or near Earth, whichever comes first. GSJ]
From: DECWRL::"usenet-space-news-request@ames.arc.nasa.gov" 8-JAN-1992
19:22:56.03
To: sci-space-news@ames.arc.nasa.gov
Subj: Galileo Status for 01/08/92 (Forwarded)
GALILEO MISSION STATUS
January 8, 1992
The Galileo spacecraft is operating normally in the all-spin
mode, with the whole spacecraft rotating at 2.89 rpm. It is
transmitting coded telemetry at 10 bits per second over the low-gain
antenna. Several times during the past two weeks telemetry has been
turned off and the spacecraft radio signal has been tracked, recorded,
and analyzed in a "scintillation experiment," which is studying the
Sun's outer corona. The spacecraft will pass about 3 degrees from the
Sun, as seen from Earth, on January 22, and these radio propagation
experiments will continue for some weeks. Galileo is also continuing
to collect data from the magnetometer, dust detector, and extreme
ultraviolet instrument.
The flight team is sending the command load today for Galileo's
first warming turn since May 1991. As part of the Project's plan to
use warm/cold thermal cycles to free the stuck antenna-rib pins, the
spacecraft will turn about 45 degrees off the Sun tomorrow, January 9,
so that solar radiation can warm and expand the central tower, for
about two days. The cooling turn part of this fourth thermal cycle is
planned for early February.
The Galileo spacecraft is almost 485 million kilometers (301
million miles) from Earth. It is about 340 million kilometers or 211
million miles from the Sun, and will reach aphelion, the outermost
point in its present orbit, on Saturday, January 11. Its speed in
orbit, 14.92 kilometers per second or 33,380 miles per hour, is near
its minimum. Round-trip communication time to Earth is 53 minutes 45
seconds.
From: DECWRL::"usenet-space-news-request@ames.arc.nasa.gov" 8-JAN-1992
19:58:45.71
To: sci-space-news@ames.arc.nasa.gov
Subj: Galileo Update - 1/8/92
Galileo Spacecraft Daily Report
Wednesday
January 8, 1992
The Galileo Spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 10 bps.
Yesterday, the SSI (Solid State Imaging) memory readout was accomplished
along with the initiation of the SSI thermal test over DSS-14 (Goldstone 70
meter antenna).
Today, a routine RPM 10-N thruster flushing maintenance activity is
scheduled over DSS-14 along with the uplink of the sequence memory load
for warming turn #4.
Tomorrow, the warming turn #4 sequence memory load will execute a 45
degree off-sun maneuver and the SSI thermal test is scheduled to complete
over DSS-14.
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
|
| 560.587 | Update - January 9 | MTWAIN::KLAES | All the Universe, or nothing! | Sat Jan 11 1992 16:48 | 34 |
| Article: 70
From: johnson@kelvin.jpl.nasa.gov (Glenn S. Johnson)
Newsgroups: sci.space.news
Subject: Galileo Update - 1/9/92
Date: 10 Jan 92 19:16:53 GMT
Sender: usenet
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
Galileo Spacecraft Daily Report
Thursday
January 9, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps (bits per second).
Yesterday, a routine RPM 10-N thruster flushing maintenance activity
was performed over DSS-14 (Goldstone 70 meter antenna) along with the uplink
of the sequence memory load for warming turn #4.
Today, the warming turn #4 sequence memory load will execute a 36 degree
turn to a 45 degree off-sun attitude and the SSI (Solid State Imaging) thermal
test is scheduled to complete over DSS-14.
Tomorrow, no Spacecraft activity is planned. Tracking is scheduled over
DSS-63 (Madrid 70 meter antenna) in support of the warming turn activity.
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
|
| 560.588 | Updates - January 10-13 | MTWAIN::KLAES | All the Universe, or nothing! | Tue Jan 14 1992 18:37 | 330 |
| From: DECWRL::"usenet-space-news-request@ames.arc.nasa.gov" 11-JAN-1992
17:42:24.79
To: sci-space-news@ames.arc.nasa.gov
Subj: Galileo Update - 1/10/92
Forwarded from: William O'Neil, Galileo Project Manager
Galileo Spacecraft Daily Report
Friday
January 10, 1992
The Galileo Spacecraft is operating normally in the all-spin mode
and transmitting coded telemetry at 10 bps (bits per second).
Yesterday, the warming turn #4 sequence memory load executed a 36
degree turn to a 45 degree off-sun attitude and the SSI (Solid State
Imaging) thermal test completed over DSS-14 (Goldstone 70 meter antenna).
Today, no Spacecraft activity is planned. Tracking is scheduled over
DSS-63 (Madrid 70 meter antenna) in support of the warming turn activity.
On Saturday, the Spacecraft is scheduled to execute the warming turn
sequence planned sun acquisition to return to a 5 degree off-sun attitude.
This will permit immediate collection of sun gate data. On Sunday, the
Spacecraft will be commanded to the dual-spin mode and wobble data will be
collected. All the above activities are scheduled over DSS-14.
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
From: DECWRL::"usenet-space-news-request@ames.arc.nasa.gov" 12-JAN-1992
22:38:44.93
To: sci-space-news@ames.arc.nasa.gov
Subj: Galileo Update - 01/02/92
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
December 20, 1991 - January 2, 1992
SPACECRAFT
1. The periodic RPM (Retro Propulsion Module) 10-Newton thruster "flushing"
maintenance activity was performed on December 20; all 12 thrusters were
flushed during the exercise; spacecraft performance throughout the activity was
normal.
2. A NO-OP command was sent on December 23, December 27, and January 2 to
reset the command loss timer to 264 hours, its planned value for this mission
phase.
3. Imaging instrument (SSI) routine memory readouts were performed on December
20, 23, 26, 30 and January 2 to verify the health status of the SSI.
4. The routine sun vector update was performed on December 20. This vector is
valid from December 20, 1991 to March 1, 1992.
5. On December 20, Delayed Action Commands (DACs) were loaded on the
spacecraft in support of the SSI thermal test scheduled for January 7. These
DAC commands will turn the SSI replacement heater off, SSI on, and reset
and run the SSI microprocessor in the event that acceptable SSI temperatures
are not maintained during the test. If telemetry data during the SSI thermal
test indicates acceptable temperatures are being maintained, these DAC commands
will be cancelled and the SSI thermal test allowed to complete as planned.
6. On December 30, cruise science memory readouts were performed for the EUV
(Extreme Ultraviolet Spectrometer), MAG (Magnetometer), and DDS (Dust Detector)
instruments.
7. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 2 DN and reads 16.0 volts; the AC measurement increased
1 DN and reads 44.3 volts. All other power telemetry and subsystem telemetry
are normal.
8. The Spacecraft status as of end of day January 2, 1992 was as follows:
a) System Power Margin - 35 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/star scanner
d) Spacecraft Attitude is Sun pointed; Sun Point Angle
- approximately 7.8 degrees (sun lagging)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered off except SSI, EPD,
UVS, HIC, DDS, MAG, and EUV
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 260 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The warming and Cooling Turn No. 4 mini-sequences were approved for
generation by the Project on December 20. The warming turn is scheduled to
begin on January 9, 1992, and the cooling turn on February 4, 1992.
TRAJECTORY
As of noon Thursday, January 2 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 299,755,900 miles (3.23 AU)
Distance from Sun 210,946,400 miles (2.27 AU)
Heliocentric Speed 33,400 miles per hour
Distance from Jupiter 679,994,600 miles
Round Trip Light Time 53 minutes 36 seconds
SPECIAL TOPICS
1. As of January 2, 1992, a total of 6201 real-time commands have been
transmitted to Galileo since Launch. Of these, 2204 have been pre-planned in
the sequence design and 3997 were not. In the past two weeks, 11 real time
commands were transmitted; all were pre-planned. In addition, 2742
mini-sequence commands have been transmitted since March 1991; (491 were
pre-planned and 2251 were not); none were sent the past two weeks. Major
commanding activities during these two weeks included commands to reset the
command loss timer and Delayed Action Commands in support of the SSI thermal
test on January 7, 1992.
2. Analysis of the AACS (Attitude and Articulation Control Subsystem) fault
counter array following the Cool Turn No. 3 activity indicated unexpected fault
counter increments on SBA (Spin Bearing Assembly) rate and position fault
monitors. These unexpected counts were generated because the Attitude Control
Subsystem was erroneously commanded in the sequence to a state permitting SBA
errors to accumulate. This state was the same as that in January 1990 which
resulted in AACS hardware swaps and spacecraft safing. Fortunately, unlike
January 1990, the cooling turn sequence commanded the erroneous state for a
short time so the SBA error indicators did not get large enough to trip fault
protection. To preclude the possibility of this situation recurring, the
current flight rule wording regarding this issue is being reviewed. A fix is
being implemented for subsequent warming/cooling turn activities limiting the
vulnerability period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There's no limit to what
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | can be done if it doesn't
|_____|/ |_|/ |_____|/ | matter who gets the credit.
From: DECWRL::"usenet-space-news-request@ames.arc.nasa.gov" 12-JAN-1992
22:43:28.88
To: sci-space-news@ames.arc.nasa.gov
Subj: Galileo Update - 01/09/92
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
January 3 - 9, 1992
SPACECRAFT
1. A NO-OP command was sent on January 6 to reset the command loss timer to
216 hours, its planned value for this mission phase.
2. On January 6, real time commands were sent to modify the SSI (Solid State
Imaging camera) fault protection state such that if spacecraft safing is
requested, the SSI replacement heater will be turned off while leaving the main
SSI power on to maintain CCD temperature control. The changes were to be
verified by Memory Readouts (MROs). (See Special Topic 2.) These changes were
in support of the SSI thermal test being conducted on January 7.
3. On January 6, a cruise science memory readout was performed for the EUV
(Extreme Ultraviolet Spectrometer) instrument.
4. Two more unexpected CDS (Command Data Subsystem) lock change counts were
observed over DSS-14 (Goldstone 70 meter antenna) on January 7. The spacecraft
receiver AGC (Automatic Gain Control) was at minus 168.9 db. It is possible
that these lock change counts could be an idiosyncracy of the command hardware
when operating at low signal strength. The spacecraft did not receive any
commands as a result of this anomaly.
5. Imaging instrument (SSI) routine memory readouts were performed on
January 7 and 9 to verify the health status of the SSI.
6. On January 7, in support of the SSI thermal test, real time commands were
sent, as planned, to cancel the Delayed Action Commands (DACs) which would turn
the SSI replacement heater off and turn the SSI instrument on to allow the SSI
thermal test to continue. These DACs would have been allowed to execute if the
SSI temperature trends indicated a CCD thermal limit violation could occur if
the test continued. The purpose of the SSI thermal test was to determine the
equilibrium temperature of the SSI radiator (CCD) at the 153 degree scan
platform cone angle in the case where the SSI instrument is off, SSI
replacement heater is on, and the SSI flash heater is off. This temperature
information, if within flight limits, will allow the SSI to verify safe
operations for long periods with the main power off. During the test, the SSI
instrument and heater configurations were maintained for 46 hours at which time
the SSI replacement heater was commanded back off and the instrument on. The
SSI radiator temperature (CCD) during the test went from a steady state
temperature of minus 119 degrees C to minus 118 degrees C which was well above
the CCD design lower limit of minus 130 degrees C.
7. The periodic RPM (Retro Propulsion Module) 10-Newton thruster flushing
maintenance activity was performed on January 8; all 12 thrusters were flushed
during the exercise; spacecraft performance throughout the activity was normal.
8. A routine Star Scanner Spin Rate Estimator (SSSRE) Memory Readout (MRO) was
performed on January 8 to collect star calibration data.
9. The Warming Turn No. 4 sequence memory load was sent to the spacecraft on
January 8. Additionally, MRO commands were sent to verify the sequence was
loaded correctly. The sequence was loaded on the spacecraft without incident.
The 36-degree turn to 45 degrees off-sun attitude was accomplished on
January 9. The spacecraft will remain at this off-sun attitude to warm the
tower for approximately 47 hours.
10. On January 9, real time commands were sent to change the system fault
protection to select sun point if an AACS (Attitude and Articulation Control
Subsystem) Power On Reset (POR) occurs during Warming/Cooling Turn No. 4.
11. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement remained unchanged and reads 16.1 volts; the AC measurement
decreased 1 DN and reads 43.9 volts. All other power telemetry and subsystem
telemetry are normal.
12. The Spacecraft status as of end of day January 9, 1992 was as follows:
a) System Power Margin - 30 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/acquisition sensor
d) Spacecraft Attitude is 45 degrees off sun (sun lagging)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered off except SSI, EPD
UVS, HIC, DDS, MAG and EUV
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 168 hours
Time To Initiation - 156 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Warming Turn No. 4 mini-sequence was approved for transmission by the
Project on January 7. The warming turn is scheduled to begin on January 9,
1992.
GDS (Ground Data Systems):
1. A DSN (Deep Space Network) Multimission Verification Test (MVT) was
conducted Sunday, January 5 to validate the new Group 5 telemetry string using
the Op. C software which was not successful in demonstrating Galileo support
capabilities. Two problems occurred which will require some level of retest:
(1) a MTS routing problem occurred and a work-around was found after the test,
and (2) missing GCF (Ground Communications Facility) blocks were found in
post-test data analysis.
TRAJECTORY
As of noon Thursday, January 9, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 301,285,300 miles (3.24 AU)
Distance from Sun 211,031,300 miles (2.27 AU)
Heliocentric Speed 33,400 miles per hour
Distance from Jupiter 681,807,000 miles
Round Trip Light Time 53 minutes, 54 seconds
SPECIAL TOPICS
1. As of January 9, 1992, a total of 6378 real-time commands have been
transmitted to Galileo since Launch. Of these, 2381 have been pre-planned in
the sequence design and 3997 were not. In the past week, 177 real time
commands were transmitted; all were pre-planned. In addition, 2901
mini-sequence commands have been transmitted since March 1991; (670 were
pre-planned and 2251 were not). In the past week, 169 mini-sequence commands
were transmitted. Major commanding activities during the week included
commands to reset the command loss timer, modify the spacecraft fault
protection state in the case of spacecraft safing, cancel Delayed Action
Commands (DACs) in support of the SSI thermal test, load and verify the
Warming Turn No. 4 mini-sequence, and commands to change system fault
protection to select sun point if an AACS POR occurs.
2. On January 6, while attempting to verify the SSI fault protection state
changes for the SSI thermal test, the Memory Readout (MROs) were not processed
by the ground telemetry system. This was caused by the time duration of the
MROs being less than 60 2/3 seconds, in which case the ground telemetry system
processed the downlink as a data hit. The changes were subsequently
successfully verified by a full frame ground telemetry dump of the variable
packet telemetry.
3. The eighth HGA (High Gain Antenna) anomaly review board meeting was held on
January 9 at JPL. The review focused on recently performed antenna tower
thermal analysis updates and alignment pin slipping analyses. Given the
walking-pin theory, the Board suggested that the Project consider additional
warming and cooling activities at smaller solar range near Earth 2 (second
Earth flyby).
From: DECWRL::"usenet-space-news-request@ames.arc.nasa.gov" 13-JAN-1992
20:20:06.77
To: sci-space-news@ames.arc.nasa.gov
Subj: Galileo Update - 01/13/92
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 13, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
On Saturday, the Spacecraft executed the warming turn sequence planned
sun acquisition to return to a 5 degree off-sun attitude. Initial sun gate
data indicated rib positions had not changed. On Sunday, the Spacecraft was
commanded to the dual-spin mode and wobble data collected. Additionally, real
time commands were sent to perform a "bright body" checkout of the star
scanner; no evidence of bright body interference was observed. However, the
subsequent planned star scanner shutter open activity was not performed because
of an unexplained several db drop in telemetry performance. The star scanner
open activity was replanned for today.
Today, the uplink of the sequence memory load for cooling turn 4 is
scheduled along with real-time commands to open the star scanner shutter.
Tomorrow, real-time commands are scheduled to update acquisition sensor
parameters.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.589 | Update - January 15 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Jan 16 1992 18:59 | 35 |
| Article: 112
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 01/15/92
Date: 16 Jan 92 00:36:45 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 15, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, real-time commands were sent to complete the load of Cooling
Turn #4. Three of the six previously rejected messages were successfully
loaded on the spacecraft.
Today, real-time commands were sent to complete the load for Cooling
Turn #4 over DSS-63 (Madrid 70 meter antenna). All messages were verified as
being successfully loaded on the spacecraft.
Tomorrow, the SSI (Solid State Imaging camera) and EUV (Extreme
Ultraviolet Spectrometer) memory readouts are scheduled over DSS-14 (Goldstone
70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.591 | Update - January 16 | MTWAIN::KLAES | All the Universe, or nothing! | Mon Jan 20 1992 21:27 | 249 |
| Article: 117
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 01/16/92
Date: 16 Jan 92 21:33:59 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 16, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps (bits/second)
Today, the SSI (Solid State Imaging camera) and EUV (Extreme Ultraviolet
Spectrometer) memory readouts are scheduled over DSS-14 (Goldstone 70 meter
antenna).
Tomorrow, no spacecraft activity is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 124
From: yee@trident.arc.nasa.gov (Peter E. Yee)
Newsgroups: sci.space.news
Subject: Galileo Update - 1/16/92 #2
Date: 17 Jan 92 01:24:08 GMT
Sender: usenet
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
January 16, 1992
The Galileo spacecraft is 486 million kilometers (302 million
miles) from Earth; round-trip communication time is now 53 minutes 55
seconds. Its distance from the Sun is about 339.6 million kilometers,
slowly decreasing since Saturday January 11. At that time the
spacecraft passed through aphelion, the outer end of its two-year
orbit around the Sun; its speed in orbit, now 14.9 kilometers per
second (33,383 mph) is now gradually rising again.
Also on Saturday Galileo completed the warming portion of the
first temperature cycle of 1992, in the continuing program aimed at
freeing the stuck ribs of the high-gain antenna. The temperature
excursion was small at this time, because of the distance from the
Sun, and no ribs were expected to come free. The cooling turn is set
for February 4-6.
During the last few days the team succfessfully transmitted the
sequence memory load for that February cooling turn, in spite of
apparent radio noise attributed to Galileo's near alignment with the
Sun at this time. Solar conjunction, at 3 degrees, will occur next
Wednesday, January 22.
Galileo is operating normally and in good health; it is in the
all-spin mode, transmitting coded telemetry at 10 bits per second over
the low-gain antenna.
Article: 123
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update for 01/10-16/92
Date: 17 Jan 92 01:18:00 GMT
Sender: usenet
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
January 10 - 16, 1992
SPACECRAFT
1. On January 11, the spacecraft executed the planned warming turn sun
acquisition to return to a 5 degree off-sun attitude. After the sun
acquisition, sun gate data was collected to determine if an antenna rib is
still obscuring the sun gate signal. Data analysis indicates that the sun
gate is still obscured, confirming no rib release.
2. On January 12, the spacecraft went through aphelion at a solar distance of
2.27 AU.
3. On January 12, as part of the Warming Turn No. 4 activities, the AACS
(Attitude and Articulation Control Subsystem) gyro-based wobble data was
collected. The wobble test was performed with the spacecraft in the dual-spin
mode. Analysis of the data indicates no change in wobble from the warming
turn.
4. As part of the Warming Turn No. 4 activities, real-time commands were sent
on January 12 to determine the possible presence of bright bodies in the star
scanner field of view. No evidence of bright body interference was observed.
This activity is performed after each HGA (High Gain Antenna) thermal turn as a
precaution to protect the star scanner from "seeing" bright particles which
could have been released if the HGA ribs released. However, the subsequent
planned star scanner shutter open activity was not performed because of an
unexplained several db drop in telemetry performance (see Special Topic 2).
5. On January 13, real-time commands to open the star scanner shutter were
sent. The commands were not received by the spacecraft, therefore the star
scanner shutter remained closed. The commands were retransmitted on
January 14, which successfully opened the star scanner shutter.
6. The Cooling Turn No. 4 sequence memory load was sent to the spacecraft as
planned on January 13. Of the 58 messages comprising the memory load, 24
messages were rejected. Later, Delayed Action Commands (DACs) were sent to
ensure the proper scan type mode during transition from dual-spin to all-spin
at the cooling attitude. These commands were properly received by the
spacecraft. The memory load was retransmitted over DSS-14 (Goldstone 70 meter
antenna). During this second attempt, 17 of the previous 24 rejected messages
were correctly loaded on the spacecraft. On January 14, the rejected messages
were retransmitted over DSS-14 along with associated memory readouts. None of
these commands were received by the spacecraft. The rejected messages were
again sent over DSS-14 using the 400kw transmitter. During this attempt, 3 of
the previously rejected messages were loaded on the spacecraft. On January 15,
commanding was then accomplished over DSS-63 (Madrid 70 meter antenna) using
their 400kw transmitter. All the remaining messages were verified as being
successfully loaded on the spacecraft (see Special Topic 2). The pre-cool
portion of the sequence will begin on January 28. The turn will begin on
February 4.
7. On January 13, the Telemetry Modulation Unit (TMU) drivers were commanded
on, overriding sequence issued commands to turn the TMU drivers off. These
commands were required to maintain 10 bps downlink telemetry while continuing
to uplink the Cooling Turn No. 4 sequence memory load (see Special Topic 2).
8. On January 13, real-time commands were sent to turn the two way
non-coherent (TWNC) on (see Special Topic 2).
9. On January 13, cruise science memory readouts were performed for the
Magnetometer and dust (DDS) instruments.
10. Imaging instrument (SSI) routine memory readouts were performed on
January 13 and 16 to verify the health status of the SSI.
11. On January 14, real-time commands were sent to restore the acquisition
sensor parameters so that sun acquisitions will terminate at a directly sun
pointed attitude. The memory readouts (MROs) indicated that the off-line
memory addresses were not updated with the new parameters. The on-line memory
updates were confirmed by subsequent MROs (see Special Topic 2).
12. On January 16, cruise science memory readouts were performed for the EUV
(Extreme Ultraviolet Spectrometer) instrument.
13. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 6 DN and reads 16.8 volts; the AC measurement decreased
3 DN and reads 43.3 volts. All other power telemetry and subsystem telemetry
are normal.
14. The Spacecraft status as of end of day January 16, 1992 was as follows:
a) System Power Margin - 34 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.88 rpm/star scanner
d) Spacecraft Attitude is sun pointed; sun point angle
is approximately 5 degrees off-sun
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all powered off except SSI, EPD
UVS, HIC, DDS, MAG and EUV
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 432 hours
Time To Initiation - 400 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Cooling Turn No. 4 mini-sequence was approved for transmission by the
Project on January 10. The cooling turn is scheduled to begin on February 4,
1992.
2. The EE-5 (Earth-Earth 5) final cruise plan was approved by the Project
on January 16. This sequence controls spacecraft activities from March 9, 1992
to April 27, 1992.
TRAJECTORY
As of noon Thursday, January 16, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 302,114,200 miles (3.24 AU)
Distance from Sun 211,003,700 miles (2.27 AU)
Heliocentric Speed 33,400 miles per hour
Distance from Jupiter 683,477,300 miles
Round Trip Light Time 54 minutes, 4 seconds
SPECIAL TOPICS
1. As of January 16, 1992, a total of 6968 real-time commands have been
transmitted to Galileo since Launch. Of these, 2446 have been pre-planned in
the sequence design and 4522 were not. In the past week, 590 real time
commands were transmitted; 65 were pre-planned and 525 were not. In addition,
3099 mini-sequence commands have been transmitted since March 1991; (858 were
pre-planned and 2251 were not). In the past week, 198 mini-sequence commands
were transmitted. Major commanding activities during the week included
commands to checkout and open the star scanner, load and verify the Cooling
Turn No. 4 mini-sequence, turn on the Telemetry Modulation Unit (TMU) and the
two way non-coherent (TWNC), and update acquisition sensor parameters.
2. While reconfiguring the spacecraft after Warming Turn No. 4 on January 12,
anomalous command and telemetry signatures were observed. The spacecraft
downlink was configured with the two way non-coherent (TWNC) off, telemetry
rate was 10 bps, solar range was 2.27 AU, Earth range was about 3.25 AU, and
the spacecraft was about 6.3 degrees of the sun moving toward solar
conjunction. On January 12, while uplinking the planned star scanner
bright-body checkout sequence over DSS-14, the CDS (Command Data Subsystem)
telemetry indicated that bit errors were detected and corrected with the
sequence being accepted. During the same day, while over DSS-14, the ground
AGC (Automatic Gain Control) and SNR (Signal-to-Noise Ratio) telemetry
indicators showed a gradual 6 db performance drop, thereby precluding the
processing of spacecraft telemetry data. Consequently, the planned realtime
commanding over DSS-14 to open the star scanner shutter was not performed.
Later that day over DSS-43 (Canberra 70 meter antenna), similar degraded
telemetry performance was observed but improved enough to verify the spacecraft
was normal. No further action was taken on January 12. The cause of the
anomaly was unknown but speculated to be either DSN related or solar
conjunction related. A spacecraft problem, although possible, appeared
unlikely. Telemetry and command performance continued to worsen until
January 15.
Prior to entering the solar conjunction command moratorium from January 14
through January 30 (5 degrees), commanding was necessary to restore the
acquisition sensor parameters from 5 degrees to sun point, open the star
scanner shutter, and to uplink the Cooling Turn No. 4 sequence memory load.
Multiple command transmissions were performed. The acquisition sensor
parameter updates and star scanner shutter open commands were sent over DSS-43
using the 100kw transmitter and telemetry verified proper receipt on
January 14. The Cooling Turn No. 4 sequence memory load was sent over DSS-14
using the 100kw and 400kw transmitter and over DSS-63 using their 400kw
transmitter. The sequence memory load was finally verified with telemetry on
January 15. Therefore, the spacecraft was properly configured and is prepared
to execute the planned Cooling Turn No. 4 activity on January 28 with the
cooling turn scheduled to occur on February 4.
|
| 560.592 | Updates - January 20-21 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Jan 22 1992 22:22 | 69 |
| Article: 138
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 01/20/92
Date: 21 Jan 92 00:33:41 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 20, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps.
There was no planned Spacecraft activity over the weekend. Frequent
(near continuous) tracking was performed in support of the Radio Science
Scintillation experiment.
Today, SSI (Solid State Imaging) memory readouts are scheduled over
DSS-14 (Goldstone 70 meter antenna).
Tomorrow, no Spacecraft activity is scheduled. Frequent (near continuous)
tracking is scheduled in support of the Radio Science Scintillation experiment.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 142
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 01/21/92
Date: 21 Jan 92 22:26:25 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 21, 1992
The Galileo Spacecraft, with the limited telemetry visibility due to
solar conjunction, appears to be operating normally in the all-spin mode.
Yesterday, telemetry at 10 bps along with SSI (Solid State Imaging
camera) memory readouts were scheduled over DSS-14 (Goldstone 70 meter
antenna). The memory readouts were corrupted due to interference attributed
to the solar conjunction period. During the track, the telemetry signal kept
going in and out of lock and there were numerous data hits, as expected. The
next telemetry pass is scheduled over DSS-14 on January 23, 1992.
Today, no Spacecraft activity is scheduled. Frequent (near continuous)
tracking is scheduled in support of the Radio Science Scintillation experiment.
Tomorrow, no Spacecraft activity is scheduled. Frequent (near continuous)
tracking is scheduled in support of the Radio Science Scintillation experiment.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.593 | GALILEO's antenna history | MTWAIN::KLAES | All the Universe, or nothing! | Wed Jan 29 1992 17:15 | 37 |
| Article: 39700
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space
Subject: Re: JPL Interplanetary Probes
Date: 28 Jan 92 08:26:44 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
In article <1992Jan27.204539.28768@zoo.toronto.edu>,
henry@zoo.toronto.edu (Henry Spencer) writes...
>The reason for using the folding antenna was very simple: it's *bigger*.
>Galileo's antenna, fully unfolded, is too big to fit in the shuttle cargo
>bay (or any current US expendable shroud either). The Voyagers had the
>biggest rigid antenna that would fit in a Centaur shroud; Galileo's higher
>data rates meant it needed something still bigger, and the TDRS-type antenna
>looked like a reasonable approach.
I double checked my references, and Henry's right. The HGA was folded
up to fit in the Shuttle. I believe the original design in the early
1970s had a hard HGA antenna, but as requirements change as they
inevitably do, a larger HGA became necessary. An additional note
about the VEEGA trajectory: had Galileo taken a direct trajectory from
the Shuttle to Jupiter, this would have allowed the opportunity to
open the HGA immediately after deployment with an astronaut hanging
around to provide assistance if necessary. This was done with Hubble
and GRO as they opened their solar arrays after Shuttle deployment.
But with the VEEGA trajectory, Galileo had to keep its HGA furled up for
thermal protection until it was permamently beyond 1 AU from the Sun.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.594 | Updates - January 22-27 | MTWAIN::KLAES | All the Universe, or nothing! | Wed Jan 29 1992 17:53 | 266 |
| Article: 173
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 01/22/92
Date: 26 Jan 92 04:11:16 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 22, 1992
The Galileo Spacecraft, with the limited telemetry visibility due to
solar conjunction, appears to be operating normally in the all-spin mode.
Yesterday, no Spacecraft activity was scheduled. Frequent (near
continuous) tracking was performed in support of the Radio Science
Scintillation experiment.
Today, no Spacecraft activity is scheduled. Frequent (near continuous)
tracking is scheduled in support of the Radio Science Scintillation experiment.
Tomorrow, routine SSI (Solid State Imaging camera) memory readouts are
scheduled along with cruise science memory readouts for the Extreme Ultraviolet
subsystem (EUV), Dust Detector subsystem (DDS), and the Magnetometer subsystem
(MAG).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 156
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 01/22/92
Date: 25 Jan 92 22:06:52 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
January 22, 1992
The Galileo spacecraft is more than 486 million kilometers (302
million miles) from Earth; this distance is now slowly decreasing
after reaching a peak yesterday. The distance from the Sun, about
339.4 million kilometers, is also slowly closing after the January 11
maximum. Speed in orbit is 14.9 kilometers per second (33,417 mph)
and rising. Today the spacecraft is at solar conjunction, the closest
alignment to the Sun, 3 degrees, as seen from Earth.
Because of this solar conjunction, which affects communications
between Galileo and Earth, no commands and only limited telemetry
activity were planned or conducted since last week. Telemetry
received indicates that the spacecraft is operating normally.
While the telemetry has been turned off, the radio science team
is collecting valuable data for what is called the radio scintillation
experiment, to study the Sun's outer corona.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 169
From: yee@trident.arc.nasa.gov (Peter E. Yee)
Newsgroups: sci.space.news
Subject: Galileo Update - 01/24/92
Date: 25 Jan 92 23:00:12 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 24, 1992
Telemetry visibility yesterday was slightly improved and allowed some
more detailed Spacecraft status assessment. All available telemetry indicates
that the Spacecraft is operating normally in the all-spin mode.
Yesterday, telemetry at 10 bps along with Memory Readouts (MROs) of the
Solid-State Imaging (SSI), Extreme Ultraviolet Spectrometer (EUV), Dust
Detector (DDS), and the Magnetometer (MAG) were scheduled over DSS-14
(Goldstone 70 meter antenna). The SSI MRO was not received due to interference
attributed to the solar conjunction period. During the track, the telemetry
signal kept going in and out of lock and there were numerous data hits, as
expected. The next telemetry pass is scheduled over DSS-14 on January 27.
Today, no Spacecraft activity is scheduled and telemetry will not be
available. Frequent (near continuous) tracking is scheduled in support of the
Radio Science Scintillation experiment.
Over the weekend, no spacecraft activity is scheduled and telemetry will
not be available. Frequent (near continuous) tracking is scheduled in support
of the Radio Science Scintillation experiment.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 170
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 01/24/92
Date: 25 Jan 92 23:05:03 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
January 17 - 23, 1992
SPACECRAFT
1. On January 18, the solar wind scintillation experiment data collection
began; it will continue through January 27.
2. Imaging instrument (SSI) routine memory readouts were performed on
January 20 and 23 to verify the health status of the SSI. On January 20,
the memory readout was corrupted due to interference attributed to solar
conjunction. The memory readout on January 23 was not received due to poor
telemetry data.
3. The Galileo spacecraft entered the solar conjunction period on January 13,
1992. This is the time period in which the angle between the line of sight to
the spacecraft and the line of sight to the sun is less than 5 degrees. The
minimum solar conjunction angle of 2.27 degrees occurred on January 22. The
Galileo spacecraft will exit the solar conjunction period on January 30, 1992.
During the two telemetry tracks this week, the telemetry signal has repeatedly
gone in and out of lock and numerous data hits have occurred. Telemetry
quality has been poor and the spacecraft status difficult to comprehensively
assess, as expected.
4. On January 23, cruise science memory readouts were performed for the
Extreme Ultraviolet subsystem (EUV), Dust Detector Subsystem (DDS), and the
Magnetometer subsystem (MAG). There were some data hits; overall data quality
is being assessed.
5. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement decreased 12 DN and reads 15.3 volts. The AC measurement increased
2 DN and reads 43.7 volts. All other power telemetry and subsystem telemetry
appear normal.
6. The Spacecraft status as of end of day January 23, 1992 was as follows:
a) System Power Margin - 34 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.88 rpm/star scanner
d) Spacecraft Attitude is sun pointed; sun point angle
is approximately 8 degrees off-sun
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EPD, UVS, HIC, DDS, MAG
and EUV are powered on
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 432 hours
Time To Initiation - 230 hours
GDS (Ground Data Systems):
1. The January System Engineer's Monthly Report (SEMR) was conducted Tuesday,
January 21. A review of current Project and Institutional (FPSO & DSN) system
status was conducted. Pre-Earth 2 delivery schedules, past month
accomplishments and potential problem areas were discussed. A total 53
program sets are planned to be delivered prior to Earth 2. No Criticality 1
or 2 failure reports were generated during the past month reporting period.
2. The Galileo TDA (Telecommunications & Data Acquisition) Manager gave a
presentation to the Project on the DSN (Deep Space Network) Telemetry System
upgrades at the SPCs (Signal Processing Centers). Pending Project software
changes, workarounds will be required to process telemetry from the new
strings. Verification of these workarounds in GDS tests is required before
the new configuration is used for Galileo operations support. These tests
will be conducted in the near future after telemetry performance has improved
sufficiently with the Galileo spacecraft after solar conjunction.
TRAJECTORY
As of noon Thursday, January 23, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 302,248,100 miles (3.25 AU)
Distance from Sun 210,863,700 miles (2.27 AU)
Heliocentric Speed 33,400 miles per hour
Distance from Jupiter 685,006,000 miles
Round Trip Light Time 54 minutes, 6 seconds
SPECIAL TOPICS
1. As of January 23, 1992, a total of 6968 real-time commands have been
transmitted to Galileo since Launch. Of these, 2446 have been pre-planned in
the sequence design and 4522 were not. In the past week, no real time commands
were transmitted. In addition, 3099 mini-sequence commands have been
transmitted since March 1991; (858 were pre-planned and 2251 were not). In the
past week, no mini-sequence commands were transmitted.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 19917
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/27/92
Date: 28 Jan 92 03:50:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
[I'll be temporarily posting the JPL status reports here until Peter Yee
returns from travel later this week. The autoforward program to
sci.space.news doesn't seem to like my site for some reason. - Ron Baalke ]
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 27, 1992
The Galileo Spacecraft, with the limited telemetry visibility due to
solar conjunction, appears to be operating normally in the all-spin mode.
Over the weekend, no spacecraft activity was scheduled and
telemetry was not available. Frequent (near continuous) tracking was
scheduled in support of the Radio Science Scintillation experiment.
Today, a routine RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance activity is scheduled over DSS-14 (Goldstone 70
meter antenna) along with a sun acquisition, a Star Scanner Spin Rate
Estimator (SSSRE) Memory Readout (MRO) to collect star calibration
data, and a routine Solid-State Imaging (SSI) MRO.
Tomorrow, the pre-cool portion of Cooling Turn #4 will begin.
Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.595 | Update - January 28 | MTWAIN::KLAES | All the Universe, or nothing! | Thu Jan 30 1992 13:24 | 35 |
| Article: 19944
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/28/92
Date: 28 Jan 92 23:36:31 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 28, 1992
Telemetry visibility yesterday was improved and allowed more detailed
Spacecraft status assessment. All available telemetry indicates that the
Spacecraft is operating normally in the dual-spin mode.
Yesterday, a routine RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance activity was performed over DSS-14 (Goldstone 70 meter
antenna) along with a sun acquisition, a Star Scanner Spin Rate Estimator
(SSSRE) Memory Readout (MRO) and a routine Solid-State Imaging (SSI) MRO.
Today, the pre-cool portion of Cooling Turn #4 will begin. The turn will
be executed on February 4. Tracking is scheduled over DSS-14.
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.596 | Update - January 29 | VERGA::KLAES | All the Universe, or nothing! | Mon Feb 03 1992 16:23 | 41 |
| Article: 19964
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 01/29/92
Date: 29 Jan 92 21:19:46 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
January 29, 1992
The Galileo spacecraft is 485.7 million kilometers (almost 302
million miles) from Earth; the round-trip communication time is 53
minutes 53 seconds. The spacecraft is 339 million kilometers from the
Sun, and its speed in orbit is 14.97 kilometers per second (33,483 mph).
The spacecraft is still considered to be in the solar conjunction
region (less than 5 degrees from the Sun as seen from Earth). This
condition began January 13 and will end tomorrow, January 30. During
this period solar effects have made telemetry reception from the
spacecraft noisy, and planned spacecraft activity has been limited.
The radio science team has been collecting data for the Radio
Scintillation Experiment.
As planned, on January 28 the spacecraft began the pre-cool part
of the next cooling turn. The turn itself will be conducted February 4-6.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.597 | Updates - January 30-31 | VERGA::KLAES | All the Universe, or nothing! | Wed Feb 05 1992 00:03 | 203 |
| Article: 20021
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/30/92
Date: 30 Jan 92 20:31:19 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 30, 1992
The Galileo Spacecraft appears to be operating normally in the dual-spin
mode and transmitting coded telemetry at 10bps. In accordance with the Cooling
Turn No. 4 mini-sequence we are operating in a S-Band TWTA (transmitter) low
power mode and have not received telemetry since Tuesday PM, as expected.
Yesterday, no Spacecraft activity was scheduled. Tracking was scheduled
over DSS-43 (Canberra 70 meter antenna).
Today, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-14 (Goldstone 70 meter antenna).
Tomorrow, real-time commands to turn the Two Way Non-Coherent (TWNC) on
and off are scheduled in order to reset the Command Loss Timer to 11 days.
Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 20030
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update #2 - 01/30/92
Date: 31 Jan 92 01:01:32 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
January 24 - 30, 1992
SPACECRAFT
1. The Galileo spacecraft was within the solar conjunction region during the
week. This is the time period in which the angle between the line of sight to
the spacecraft and the line of sight to the sun is less than 5 degrees. The
angle ranged from 2.4 degrees on January 24 to 5.2 degrees at the end of the
day on January 30. The Galileo spacecraft exited the solar conjunction region
on January 30, 1992. Telemetry passes at 10 bps were scheduled for January 27
and 28 at which time the S-band TWTA (transmitter) was commanded to the low
power mode in preparation for the pre-cooling portion of Cooling Turn No. 4.
As expected, downlink telemetry over these two days continued to improve over
last week as the solar conjunction angle increased. However, with the S-Band
TWTA in the low power mode, telemetry performance will be marginal even outside
the solar conjunction region.
2. On January 27, a sun acquisition was performed using the P-thrusters which
returned the spacecraft from a 9 degree off-sun attitude to a sun-pointed
attitude.
3. On January 27, a periodic RPM (Retro Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed. This activity flushed all twelve
thrusters. Spacecraft performance throughout the activity was normal.
4. A routine Star Scanner Spin Rate Estimator (SSSRE) Memory Readout (MRO) was
performed on January 27 to collect star calibration data; there were telemetry
data hits and AACS (Attitude and Articulation Control Subsystem) is evaluating
the usability of the data.
5. Solid-State Imaging (SSI) instrument routine Memory Readouts (MROs) were
performed on January 27 to verify the health status of the SSI. There were
telemetry data hits in the MROs but the overall health of the instrument was
verified.
6. On January 28, the Cooling Turn No. 4 sequence memory load went active.
The pre-cool portion of the sequence started on January 28 and will be
completed on February 4. The turn activity will begin on February 4 (see
Special Topic No. 2).
7. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 13 DN and reads 16.9 volts. The AC measurement increased
1 DN and reads 43.9 volts. All other power telemetry and subsystem telemetry
appear normal.
8. The Spacecraft status as of end of day January 30, 1992 could not be
determined by real-time telemetry because the spacecraft has been configured
for the pre-cool portion of Cooling Turn No. 4 with the S-band TWTA commanded
to low power. The following information is taken from previous spacecraft
performance and predicts.
a) System Power Margin - 34 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is sun pointed; sun point angle
is approximately 1 degree off-sun
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EPD, and UVS are powered on
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 432 hours
Time To Initiation - 60 hours
TRAJECTORY
As of noon Thursday, January 30, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 301,687,800 miles (3.25 AU)
Distance from Sun 210,611,000 miles (2.27 AU)
Heliocentric Speed 33,500 miles per hour
Distance from Jupiter 686,393,400 miles
Round Trip Light Time 54 minutes 0 seconds
SPECIAL TOPICS
1. As of January 30, 1992, a total of 6968 real-time commands have been
transmitted to Galileo since Launch. Of these, 2446 have been pre-planned in
the sequence design and 4522 were not. In the past week, no real time commands
were transmitted. In addition, 3099 mini-sequence commands have been
transmitted since March 1991; (858 were pre-planned and 2251 were not). In the
past week, no mini-sequence commands were transmitted.
2. The Cooling Turn No. 4 activities are scheduled from January 28 through
February 8, 1992. The spacecraft bus cool down period started on January 28
and will continue until February 4. The cooling turn will be performed on
February 4 and will be at the cooling attitude for approximately 50 hours.
The spacecraft turn back from the cooling attitude is schedule for February 7.
The sun gate and wobble ID data collection is scheduled during the February 7-8
time period.
During the uplink of Cooling Turn No. 4 on January 13 through 15, there
were bit errors on the uplink causing commands to be rejected. After a
detailed analysis of the risk in commanding in the presence of bit errors, it
has been determined that there is a finite, although very small probability,
that a command frame error could result in an improperly loaded memory location
or a data frame error could result in an improperly loaded sequence. To
further assure us that these types of errors have not occurred during the
uplink of Cooling Turn No. 4, memory readouts are being planned on February
2 to verify the state of the global variable parameters and the content of the
last six load messages that were sent numerous times during the memory load
uplink attempts. If these memory readouts are successfully verified, the
Cooling Turn No. 4 sequence will be allowed to complete. If the memory
readouts are unsuccessful or errors are found in the data, the Cooling Turn
No. 4 sequence will be terminated.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 20019
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 01/31/92
Date: 31 Jan 92 17:54:59 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 31, 1992
The Galileo Spacecraft appears to be operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps. In accordance with the
Cooling Turn No. 4 mini-sequence, we are operating in a S-Band TWTA
(transmitter) low power mode and have not processed telemetry since Tuesday PM,
as expected. This morning we were able for brief periods to maintain lock and
to process some telemetry.
Yesterday, no Spacecraft activity was scheduled.
Today, real-time commands to turn the Two Way Non-Coherent (TWNC) off and
on are scheduled in order to reset the Command Loss Timer to 11 days; tracking
is scheduled over DSS-14 (Goldstone 70 meter antenna).
On February 2, real-time commands are scheduled to perform memory readouts
of global variables and selected portions of the Cooling Turn No. 4 sequence
load. Other command activities scheduled are: magnetometer instrument power on
and resetting AACS (Attitude and Articulation Control Subsystem) acquisition
parameters. Tracking for the weekend is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.598 | Might the HGA still have a partial XMIT chance? | TINCUP::J_BUTLER | E poi, si muove... | Thu Feb 06 1992 20:38 | 28 |
| A few questions:
OK, if we _can't_ free the antenna what are the problems with using
the _partially_ deployed HGA?
Is it _physical_? Perhaps a contact is closed/opened when the HGA is
fully deployed thus preventing communications?
Is it "electronic"? The signal would be so distorted as to be
unintelligible?
It would seem to me (a non-technical dude with some experience in
military communications systems) that the more powerful transmitter
used with the HGA could still punch out a usable signal. Test
transmissions could be made, where Galileo simply responds with
a known sequence. The "shift" could then be accounted for. Granted, it
would take a LOT of effort...but that effort would be here on Earth
where we can put a great deal of mind and computer power on the task.
Sure, it might mean changing Galileo's attitude to orient the warped
dish so we can get the signal, but even a usable rate of 1200 bps
from Jupiter space would be better than 10...or 40.
Is anybody considering the issue?
Thanks!
John B.
|
| 560.599 | I doubt it very much | REPAIR::RICKETTS | Have you tried kicking it? | Fri Feb 07 1992 11:33 | 10 |
| As far as I understand it, the HGA was supposed to open rather like
an umbrella. Imagine an umbrella with several of the ribs still stuck
to the central shaft, and what sort of shape it would take up, then
compare that with a circular radio/radar dish (such as most satellite TV
receivers). Even if the transmitter could operate with the antenna in this
shape, the dish would not reflect a useful signal for any worthwhile
distance. The purpose of the HGA is to direct the signal from the
xmtr into a fairly narrow beam, and it has to be the right shape to do that.
Ken
|
| 560.600 | | HELIX::MAIEWSKI | | Fri Feb 07 1992 16:00 | 7 |
| Add to that the fact that even if they could get some signal, there's little
chance that it would be better than the low gain signal. What ever techniques
used to make the half opened signal better would probably apply to the low
gain signal as well. This include data compression, bigger ground receivers,
etc.
George
|
| 560.601 | Update - February 3 | VERGA::KLAES | All the Universe, or nothing! | Sat Feb 08 1992 18:33 | 35 |
| Article: 239
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/03/92
Date: 3 Feb 92 19:18:48 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 3, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps (bits/second).
On February 2, real-time commands were sent to perform memory readouts of
global variables and selected portions of the Cooling Turn No. 4 sequence load.
Other command activities included turning on the magnetometer instrument and
resetting AACS (Attitude and Articulation Control Subsystem) acquisition
parameters.
Today, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-14 (Goldstone 70 meter antenna).
Tomorrow, the Spacecraft will execute the cooling turn to 165 degrees off
sun over DSS-14. The turn is scheduled to begin about 1:00 pm (PST).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.602 | Updates - February 4-13 | VERGA::KLAES | All the Universe, or nothing! | Fri Feb 14 1992 20:16 | 461 |
| Article: 262
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/04/92
Date: 4 Feb 92 21:33:48 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 4, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, no Spacecraft activity was scheduled. Tracking was scheduled
over DSS-14 (Goldstone 70 meter antenna).
Today, the Spacecraft will execute the cooling turn to 165 degrees off
sun over DSS-14. The turn is scheduled to begin about 1:00 pm (PST).
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-63 (Madrid 70 meter antenna) and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 280
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/05/92
Date: 6 Feb 92 17:27:07 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
February 5, 1992
The Galileo spacecraft is almost 484 million kilometers
(more than 300 million miles) from Earth, and about 338 million
kilometers from the Sun. Its speed in orbit is 15 kilometers per
second or about 33,600 mph.
Spacecraft health and performance are generally excellent.
Galileo is currently in the all-spin mode, rotating at about 2.9
rpm, with its spin axis pointed about 165 degrees away from the
Sun. The spacecraft turned to the 165-degree attitude yesterday
afternoon (Tuesday) and is programmed to turn back tomorrow night
(Thursday, February 6).
Last week, several electrical devices were switched off to
provide pre-cooling. This is Galileo's fourth cooling turn in a
program of thermal cycling designed to free three ribs of the
high-gain antenna (believed stuck in the stowed position) to
permit the antenna to be fully deployed.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 281
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/06/92
Date: 6 Feb 92 18:10:53 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 6, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps. We expect to reacquire downlink
telemetry tomorrow at approximately 0315 UTC.
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, February 6, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43 (Canberra 70 meter antenna) and DSS-63. Tracking at the
165 degree off-sun attitude is a precautionary measure since the dwell at
attitude is done in the blind. The tracking periods are designed to provide
early warning of any entry into fault protection; no problems are expected.
Tomorrow, the spacecraft is scheduled to execute the cooling turn sequence
planned sun acquisition to return to a 5 degree off-sun attitude. The turn is
scheduled to complete at approximately 0337 UTC. Tracking is scheduled over
DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 290
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 02/06/92
Date: 6 Feb 92 23:08:49 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
January 31 - February 6, 1992
SPACECRAFT
1. On January 31, commands were sent to turn the Two Way Non-Coherent (TWNC)
off and on in order to reset the command loss timer to 11 days. The commands
were verified via the doppler shift (approximately 1200 hertz) in the downlink
signal.
2. On February 2, commands were sent to turn off the external shunt heater 1B
(raise the power margin) and to turn the S-band TWTA to the high power mode in
order to achieve telemetry visibility for verification of the upcoming planned
commanding. Then a Delayed Action Command (DAC) was transmitted which is
scheduled to execute on February 7 as a backup to the Cooling Turn No. 4
sequence 7 SUN command which will initiate a sun acquisition, returning the
spacecraft from the 165 degree off sun attitude to a 5-degree off sun attitude.
Memory Readouts (MROs) were then sent to verify the state of the fault
protection global variable parameters and the content of the last six load
messages for Cooling Turn No. 4. All memory readouts were successfully
verified to be correct and the cooling Turn No. 4 sequence allowed to continue.
Commands to update the AACS (Attitude and Articulation Control Subsystem)
acquisition sensor on-line parameters to a 5 degree off-sun attitude were then
sent and verified. Finally, commands were sent to return the S-Band TWTA
to the low power mode (continue spacecraft bus cooling) and turn the external
shunt heater 1B back on (lower the power margin).
3. On February 2, commands were sent to turn the Magnetometer (MAG) instrument
on to collect solar wind science data in a collaborative effort with the
Ulysses mission.
4. On February 3, the solar wind scintillation experiment data collection
began; it will continue through February 7.
5. Solid-State Imaging (SSI) instrument routine Memory Readouts (MROs) were
performed on February 4 to verify the health status of the SSI. There were a
few telemetry data hits in the MROs but the overall health of the instrument
was verified.
6. The pre-cool portion of the Cooling Turn No. 4 was completed on February 4.
The spacecraft bus cooled down from 23.3 degrees C to 19.1 degrees C during the
six day pre-cool period. The turn to 165 degrees off-sun was initiated on
February 4 at 1257 PST. The spacecraft downlink telemetry was lost as planned
at 1323 PST. The spacecraft will remain at cooling attitude for approximately
50 hours at which time the spacecraft will be commanded back to 5 degrees
off-sun. The downlink telemetry is expected to be reacquired on February 6 at
approximately 1915 PST and the turn completed at 1937 PST. The sun gate and
wobble ID data collection is scheduled during the February 7-8 time period.
7. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement remained unchanged and reads 16.9 volts. The AC measurement
decreased 4 DN and reads 43.7 volts. All other power telemetry and subsystem
telemetry appear normal.
8. The Spacecraft status as of 1700 PST on February 6, 1992 could not be
determined by real-time telemetry because the spacecraft was at the cooling
attitude with no downlink telemetry signal being received. The following
information is taken from previous spacecraft performance and predicts.
a) System Power Margin - 34 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/acquisition sensor
d) Spacecraft Attitude is 165 degrees off sun
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EPD, and MAG are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 167 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Warming Turn No. 5 mini-sequence was approved for generation by the
Project on January 31. The warming turn is scheduled to begin on
February 17, 1992.
2. Rescoping of the EE-6 (Earth-Earth 6) and EE-7 Skeleton Cruise Activity
Plan consistent with Project issued Work Plans was reviewed. With some
changes, the EE-6 & 7 SCAPs were approved on February 5.
TRAJECTORY
As of noon Thursday, February 6, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 300,715,600 miles (3.24 AU)
Distance from Sun 211,008,700 miles (2.27 AU)
Heliocentric Speed 33,400 miles per hour
Distance from Jupiter 681,047,700 miles
Round Trip Light Time 53 minutes, 48 seconds
SPECIAL TOPICS
1. As of February 6, 1992, a total of 7075 real-time commands have been
transmitted to Galileo since Launch. Of these, 2466 have been pre-planned in
the sequence design and 4609 were not. In the past week, 107 real time
commands were transmitted; 20 were pre-planned in the sequence design and 87
were not. In addition, 3099 mini-sequence commands have been transmitted since
March 1991; (858 were pre-planned and 2251 were not). None were sent this
week. Major command activities this week included: commands to turn the
Two-Way Non-Coherent (TWNC) off and on, cycle the S-band TWTA to the high and
low power mode, turn the external shunt heater 1B off and on, backup the sun
acquisition on February 7, readout portions of the Cooling Turn No. 4 memory
load and fault protection global variable parameters, update the acquisition
sensor on-line parameters, and turn the magnetometer instrument on.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 292
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/07/92
Date: 7 Feb 92 19:26:52 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 7, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps (bits/second).
Last evening, the Spacecraft executed the cooling turn sequence-planned
sun acquisition to return to a 5 degree off-sun attitude; sungate data
indicated no change in rib position.
Over the weekend, wobble data from Cooling Turn No. 4 will be collected.
Additionally, real-time commands will be sent to check out and open the star
scanner, reacquire celestial reference, and perform Magnetometer instrument
Memory Readouts (MROs). Tracking is scheduled over DSS-43 (Canberra 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 312
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/13/92
Date: 13 Feb 92 19:15:58 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 13, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, no Spacecraft activity was scheduled. Frequent (near
continuous) tracking was performed in support of the Radio Science
Scintillation experiment.
Today, February 13, Memory Readouts (MROs) are scheduled for the Solid
State Imaging (SSI) instrument, Dust Detector (DDS), and Magnetometer (MAG).
Additionally, the Warming Turn No. 5 sequence memory load is scheduled to be
uplinked.
Tomorrow, no Spacecraft activity is scheduled. Tracking over DSS-61
(Madrid 34 meter antenna) and DSS-14 (Goldstone 70 meter antenna) is scheduled
in support of the Radio Science Scintillation experiment.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 314
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 02/13/92
Date: 13 Feb 92 23:57:12 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
February 7 - 13, 1992
SPACECRAFT
1. On February 7, as part of Cooling Turn No. 4 activities, the spacecraft was
commanded back to a 5 degree off-sun attitude after remaining at the cooling
attitude for approximately 50 hours. The downlink telemetry was reacquired at
0314 UTC and the turn completed at 0337 UTC. After the sun acquisition, sun
gate data was collected to determine if an antenna rib is still obscuring the
sun gate signal. Data analysis indicates that the sun gate is still obscured,
confirming no rib release. Probe temperatures were monitored closely following
the turn activities. Probe shelf temperatures (T2) reached 26.3 degrees C
which was approximately 3 degrees above predicts but well below the maximum
allowable temperature of 35 degrees C.
2. On February 7, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
3. On February 7, commands were sent to turn the Photometric Calibration
Target (PCT) heater No. 2 on following Cooling Turn No. 4 to restore the
background state of the EE-4B (Earth-Earth 4B) sequence load.
4. On February 8, as part of Cooling Turn No. 4 activities, the AACS
(Attitude and Articulation Control Subsystem) gyro-based wobble data was
collected. The wobble test was performed with the spacecraft in the dual-spin
mode. Analysis of the data indicates no change in wobble as a result of the
cooling turn corroborating the sun gate obscuration data discussed in
Paragraph 1.
5. On February 8, as part of Cooling Turn No. 4 activities, real-time commands
were sent to determine the possible presence of bright bodies in the star
scanner field of view. No evidence of bright body interference was observed.
Subsequent real-time commands were then sent to open the star scanner shutter.
6. On February 8, as part of Cooling Turn No. 4 activities, real-time commands
were sent to load a star set and to reacquire celestial references.
7. On February 8, real-time commands were sent to perform Memory Readouts
(MROs) for the Magnetometer (MAG) instrument in order to return solar wind
science data as part of a collaborative effort with the Ulysses mission.
8. On February 10, the Earth vector was updated and a science turn (SITURN)
was commanded which oriented the spacecraft to a two degree off earth pointed
attitude (earth lagging). The turn was accomplished using the P-thrusters;
spacecraft performance throughout the turn was normal.
9. A routine Star Scanner Spin Rate Estimator (SSSRE) Memory Readout (MRO) was
performed on February 10 to collect star calibration data.
10. On February 10, cruise science memory readouts were performed for the
Extreme Ultraviolet Subsystem (EUV).
11. On February 10, the solar wind scintillation experiment data collection
began, it will continue through February 14.
12. On February 11, the Energetic Particle Detector (EPD) motor exercise was
performed which stepped the motor through its eight operating positions and
then returned it to the nominal position (No. 4).
13. Solid State Imaging (SSI) instrument routine Memory Readouts (MROs) were
performed on February 11 and 13 to verify the health status of the SSI.
14. Two more unexpected CDS (Command Data Subsystem) lock change counts were
observed within two hours of start of track over DSS-14 (Goldstone 70 meter
antenna) on February 12. It is possible that these lock change counts could
be an idiosyncracy of the command hardware when operating at low signal
strength. The spacecraft did not receive any commands as a result of the
anomaly.
15. On February 13, cruise science Memory Readouts (MROs) were performed for
the Dust Detector Subsystem (DDS) and the Magnetometer subsystem (MAG).
16. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement changed as much as 26 DN and reads 17.1 volts. The AC measurement
changed as much as 7 DN and reads 43.9 volts. All other power telemetry and
subsystem telemetry appear normal.
17. The Spacecraft status as of February 13, 1992, was as follows:
a) System Power Margin - 35 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/star scanner
d) Spacecraft Attitude is Earth pointed; Sun point angle
is approximately 4.5 degrees (Sun leading) and the
Earth point angle is approximately 2.5 degrees (Earth lagging)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EPD, MAG, HIC, UVS, and EUV are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 140 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Cooling Turn No. 5 mini-sequence was approved for generation by the
Project on February 10. The Cooling Turn is scheduled to begin on March 2,
1992.
2. The Warming Turn No. 5 mini-sequence was approved for transmission by the
Project on February 12. The Warming Turn No. 5 activities are scheduled from
February 17 through February 21, 1992. The warming turn will be performed on
February 17 and will be at the warming attitude for approximately 48 hours.
The spacecraft turn back from the warming attitude is scheduled for
February 19. The sun gate and wobble ID data collection is scheduled during
the February 20-21 time period.
TRAJECTORY
As of noon Thursday, February 13, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 298,485,753 miles (3.21 AU)
Distance from Sun 209,767,700 miles (2.26 AU)
Heliocentric Speed 33,700 miles per hour
Distance from Jupiter 688,744,800 miles
Round Trip Light Time 53 minutes, 28 seconds
SPECIAL TOPICS
1. As of February 13, 1992, a total of 7182 real-time commands have been
transmitted to Galileo since Launch. Of these, 2565 have been pre-planned
in the sequence design and 4617 were not. In the past week, 77 real time
commands were transmitted; 69 were pre-planned in the sequence design and 8
were not. In addition, 3109 mini-sequence commands have been transmitted
since March 1991; (858 were pre-planned and 2251 were not). In the past week,
no mini-sequence commands were transmitted. Major command activities this week
included: commands to reset the command loss timer, turn the Photometric
Calibration Target (PCT) heater No. 2 on, checkout and open the star scanner
shutter, reacquire celestial referenc, and readout the magnetometer instrument
memory.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.603 | Update - February 14 | VERGA::KLAES | All the Universe, or nothing! | Sun Feb 16 1992 17:03 | 36 |
| Article: 317
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/14/92
Date: 14 Feb 92 19:56:13 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 14, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, Memory Readouts (MROs) were performed for the Solid State
Imaging (SSI) instrument, Dust Detector (DDS), and Magnetometer (MAG).
Additionally, the Warming Turn No. 5 sequence memory load was uplinked to the
Spacecraft.
Today, February 14, no Spacecraft activity is scheduled. Tracking over
DSS-61 (Madrid 34 meter antenna) and DSS-14 (Goldstone 70 meter antenna) is
scheduled in support of the Radio Science Scintillation experiment.
Over the weekend, no Spacecraft activity or tracking coverage is
scheduled. The Warming Turn to a 45 degree off sun attitude is scheduled for
Monday, February 17.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
|
| 560.604 | Refresher on how JPL knows antenna is stuck | VERGA::KLAES | All the Universe, or nothing! | Fri Feb 21 1992 00:04 | 52 |
| Article: 40634
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space
Subject: Re: Galileo updates
Date: 20 Feb 92 22:23:41 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
In article <kq85joINNh9l@agate.berkeley.edu>,
jmcd@sag4.ssl.berkeley.edu (John McDonald) writes...
>Is there any other indication of the non-deployment of the
>HGA other than wobble information? Could anything else be
>causing the wobble?
Sure. The sun sensor was used to determine that rib #2 was sticking
out at only 35.3 degrees. At full deployment it should have been
sticking out at 68 degrees. When the deployment of the antenna was
attempted, the spin rate of the spacecraft was expected to slow down
(like a spinning ice skater extending out her arms), and the spin rate
did decrease, but not by the expected amount. Also the deployment
motors were drawing more current than expected and stalled 56 seconds
into the deployment attempt. This correlated nicely with the sun
sensor data. Later, the NIMS instrument was turned to take a thermal
image of the antenna, and it showed the antenna to be asymetrically
opened.
>Is there a switch on the spacecraft which didn't indicate
>deployment that we are expecting to see as an indicator as well?
Yes, there are some micro-switches that would of turned off the motors
once the antenna was fully deployed. They were never triggered.
>Is it assumed that the part of the antenna that is deployed is
>so far out of shape as to be useless for communication?
The antenna needs to be in a parabolic shape to be usable. The high
gain antenna cannot be used in its current condition.
>And, finally, have there been any alternate plans to the
>cooling/warming that have hope of freeing the two or three stuck ribs?
Alternate plans include turning on the motors a second time and
pulsing the thrusters.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
|
| 560.605 | Updates - February 17-20 | VERGA::KLAES | All the Universe, or nothing! | Fri Feb 21 1992 21:10 | 264 |
| Article: 332
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/17/92
Date: 17 Feb 92 19:26:09 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 17, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps. Over the weekend, no Spacecraft
activity or tracking coverage was scheduled.
Today, February 17, the warming turn to a 45 degree off sun attitude is
scheduled for this afternoon. Loss of telemetry data is expected about 1:30
p.m. during the maneuver to the warming turn attitude. Tracking is scheduled
over DSS-14 (Goldstone 70 meter antenna).
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-14 and DSS-43 (Canberra 70 meter antenna). Coverage is required for
radiometric data gathering purposes, and as a precautionary measure to assure
the earliest possible warning of a Spacecraft problem since we will not have
telemetry data at attitude; no problems are expected.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't wait for your ship
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to come in, paddle out to
|_____|/ |_|/ |_____|/ | it.
Article: 335
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/18/92
Date: 18 Feb 92 17:31:24 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 18, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps (bits/second).
Yesterday the warming turn to a 45 degree off sun attitude was performed.
Downlink telemetry data hits began at approximately 1:33 p.m. during the
maneuver to the warming turn attitude.
Today, February 18, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-14 (Goldstone 70 meter antenna) and DSS-43 (Canberra 70
meter antenna). Coverage is required for radiometric data gathering purposes,
and as a precautionary measure to assure the earliest possible warning of a
Spacecraft problem since we do not have telemetry data at attitude; no problems
are expected.
Tomorrow, the sun acquisition to a 5 degree off sun attitude is scheduled
to start at approximately 1:08 p.m. Telemetry data is expected to be
reacquired at approximately 1:18 p.m. with the sun acquisition completing at
1:33 p.m. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna) and
DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 340
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/19/92
Date: 19 Feb 92 19:31:10 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 19, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday no Spacecraft activity was scheduled. Tracking was scheduled
over DSS-14 (Goldstone 70 meter antenna) and DSS-43 (Canberra 70 meter
antenna).
Today, February 19, the sun acquisition to a 5 degree off sun attitude is
scheduled to start at approximately 1:08 p.m. Telemetry data is expected to be
reacquired at approximately 1:18 p.m. with the sun acquisition completing at
1:33 p.m. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna) and
DSS-14.
Tomorrow, commands to checkout the star scanner, open the star scanner
shutter and reacquire celestial reference are scheduled. Tracking is scheduled
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 346
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/20/92
Date: 20 Feb 92 17:55:00 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 20, 1991
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps (bits/second).
Yesterday the Spacecraft executed the warming turn sequence-planned sun
acquisition to return to a 5 degree off-sun attitude; sun gate data indicated
no change in rib position.
Today, February 20, commands to checkout the star scanner, open the star
scanner shutter and reacquire celestial reference are scheduled. Tracking is
scheduled over DSS-43 (Canberra 70 metern antenna).
Tomorrow, the uplink of the sequence memory load for Cooling Turn No. 5 is
scheduled. Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 354
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 02/20/92
Date: 20 Feb 92 23:28:45 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
February 14 - 20, 1992
SPACECRAFT
1. The Warming Turn No. 5 sequence memory load was sent to the spacecraft on
February 14. Additionally, Memory Readout (MRO) commands were sent to verify
the sequence was loaded correctly. The sequence was loaded on the spacecraft
without incident.
2. On February 14, real-time commands were sent to turn the Plasma Wave (PWS)
supplemental heater on in order to maintain search coil temperatures within
hardware limits. The heater is planned to be on during the subsequent
warming/cooling turns.
3. On February 17, a periodic RPM (Retro Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed. This activity flushed all 12
thrusters. Spacecraft performance throughout the activity was normal.
4. On February 17, a periodic Data Management System (DMS) conditioning
activity was performed.
5. On February 17, the Warming Turn No. 5 sequence memory load went active.
The turn to a 45-degree off-sun attitude occurred at 21:03 UTC. The downlink
telemetry became ratty at approximately 21:33 UTC and the turn completed at
approximately 21:41 UTC.
6. On February 19, as part of Warming Turn No. 5 activities, the spacecraft
was commanded back to a 5 degree off-sun attitude after remaining at the
warming attitude for approximately 48 hours. Near error-free quality downlink
telemetry was received at 21:15 UTC and the turn completed at 21:33 UTC. After
the sun acquisition, sun gate data was collected to determine if an antenna rib
is still obscuring the sun gate signal. Data analysis indicates that the sun
gate is still obscured, confirming no rib release.
7. On February 20, as part of Warming Turn No. 5 activities, realtime commands
were sent to determine the possible presence of bright bodies in the star
scanner field of view. No evidence of bright body interference was observed.
8. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement decreased 2 DN and reads 16.8 volts. The AC measurement decreased
3 DN and reads 43.3 volts. All other power telemetry and subsystem telemetry
appear normal.
9. The Spacecraft status as of February 20, 1992, was as follows:
a) System Power Margin - 30 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Acquisition Sensor
d) Spacecraft Attitude is Sun pointed; Sun point angle
is approximately 5 degrees (Sun lagging)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EPD, MAG, HIC, UVS, and EUV are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 260 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The preliminary EE-5 (Earth-Earth 5) sequence and command generation
product was approved by the Project on February 14, 1992. This sequence
controls spacecraft activities from March 10, 1992 to April 27, 1992.
2. The Cooling Turn No. 5 mini-sequence was approved for transmission by the
Project on February 20. The Cooling Turn is scheduled to begin on
March 2, 1992.
TRAJECTORY
As of noon Thursday, February 20, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 295,873,500 miles (3.19 AU)
Distance from Sun 209,176,700 miles (2.25 AU)
Heliocentric Speed 33,900 miles per hour
Distance from Jupiter 689,708,300 miles
Round Trip Light Time 53 minutes, 0 seconds
SPECIAL TOPICS
1. As of February 20, 1992, a total of 7269 real-time commands have been
transmitted to Galileo since Launch. Of these, 2650 have been pre-planned in
the sequence design and 4619 were not. In the past week, 87 real time commands
were transmitted; 85 were pre-planned in the sequence design and 2 were not. In
addition, 3176 mini-sequence commands have been transmitted since March 1991;
(925 were pre-planned and 2251 were not). In the past week, 67 mini-sequence
commands were transmitted. Major command activities this week included
commands to: uplink and verify the Warming Turn No. 5 sequence memory load,
turn the Plasma Wave (PWS) supplemental heater on, and checkout the Star
Scanner (SS).
2. The Warming Turn No. 5 activities were scheduled from February 17 through
February 21, 1992. The warming turn was performed on February 17 and was at
the warming attitude for approximately 48 hours. The spacecraft turn back from
the warming attitude was performed on February 19. The sun gate and wobble ID
data collection is scheduled during the February 19-21 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
|
| 560.606 | Updates - February 24-26 | VERGA::KLAES | All the Universe, or nothing! | Thu Feb 27 1992 15:20 | 110 |
| Article: 374
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/24/92
Date: 24 Feb 92 19:22:51 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 24, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Over the weekend, no Spacecraft activity or tracking coverage was
scheduled.
Today, February 24, the pre-cool portion of Cooling Turn No. 5 is
scheduled to begin and will continue through March 2. Tracking is scheduled
over DSS-14 (Goldstone 70 meter antenna).
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 386
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/25/92
Date: 25 Feb 92 19:05:37 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 25, 1992
The Galileo Spacecraft appears to be operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps. In accordance with the
Cooling Turning No. 5 mini-sequence, we are operating in a S-band TWTA low
power mode and have not been able to process telemetry since Monday afternoon,
as expected.
Yesterday, the pre-cool portion of Cooling Turn No. 5 began and will
continue through March 2.
Today, February 25, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-14 (Goldstone 70 meter antenna).
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 391
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/26/92
Date: 26 Feb 92 18:12:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
February 26, 1992
The Galileo spacecraft is about 472 million kilometers (293
million miles) from Earth, and almost 336 million kilometers (208
million miles or just under 2.25 astronomical units) from the Sun.
Speed in orbit is 15.2 kilometers per second (34,060 mph), and
round-trip communication time is 52 minutes, 20 seconds.
The spacecraft is operating normally in dual spin, with the upper
body rotating at 3.15 rpm and the lower part de-spun, transmitting
coded telemetry at 10 bits per second. It is being tracked daily by
the Goldstone Deep Space Station.
A warming turn was carried out autonomously by the spacecraft
last week (February 17-19); post-turn tests showed no evidence of rib
release. Pre-cooling for the next cooling turn began Monday, February
24, under a mini-sequence transmitted last week; the actual cooling
activity is scheduled for March 2-4.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
|
| 560.607 | Update - February 27 | VERGA::KLAES | All the Universe, or nothing! | Thu Feb 27 1992 19:25 | 126 |
| Article: 402
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/27/92
Date: 27 Feb 92 19:22:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
February 21 - 27, 1992
SPACECRAFT
1. On February 21, as part of Warming Turn No. 5, commands were sent to open
the Star Scanner (SS) shutter and to reacquire celestial reference.
Additionally, the AACS (Attitude and Articulation Control Subsystem) gyro-based
wobble data was collected. The wobble test was performed with the spacecraft
in the dual-spin mode. Analysis of the data indicates no change in wobble as a
result of the warming turn corroborating the sun gate obscuration data.
2. On February 21, the Cooling Turn No. 5 sequence memory load was uplinked to
the spacecraft. Additionally, Memory Readout (MRO) commands were sent to
verify the sequence was loaded correctly. The sequence was loaded on the
spacecraft without incident (see Special Topic 2).
3. On February 21, commands were sent to clear the spun critical controller
(CRC) status register and telemetry indicator which had been incremented during
the commanding difficulties when uplinking the Warming Turn No. 4 sequence
memory load in the mid-January timeframe.
4. On February 21, commands were sent to clear the AACS fault protection high
water mark array. The high water mark array provides visibility into the AACS
fault monitors and was reset to track future occurrences of fault monitor
increments.
5. On February 21, Delayed Action Commands (DACs) were sent which will turn
the 400 Newton engine heater off. The commands are scheduled to execute on
March 2 in order to maintain the appropriate power margin during the Cooling
Turn No. 5 sequence.
6. Solid-State Imaging (SSI) instrument routine Memory Readouts (MROs) were
performed on February 21 to verify the health status of the SSI. The
instrument checkout was nominal.
7. On February 24, the Cooling Turn No. 5 sequence memory load went active.
The pre-cool portion of the sequence started on February 24 and will be
completed on March 2. During this period we are operating in the S-band TWTA
low power mode and have not been able to consistently process telemetry since
February 24 at approximately 2100 UTC, as expected. However, we were able on
February 26 and 27 for periods up to 1 hour and 48 minutes to maintain lock and
process some telemetry.
8. On February 24, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
9. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement decreased 1 DN and reads 16.7 volts. The AC measurement increased
4 DN and reads 44.1 volts. All other power telemetry and subsystem telemetry
appear normal.
10. The Spacecraft status as of February 27, 1992, was as follows:
a) System Power Margin - 29 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.14 rpm/Star Scanner
d) Spacecraft Attitude is Sun pointed; Sun point angle
is approximately 7 degrees (Sun lagging)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EPD, MAG, & UVS are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 183 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The final EE-5 (Earth-Earth 5) sequence and command generation product
was approved by the Project on February 21, 1992. This sequence controls
spacecraft activities from March 10, 1992 to April 27, 1992.
TRAJECTORY
As of noon Thursday, February 27, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 292,610,400 miles (3.15 AU)
Distance from Sun 208,472,500 miles (2.24 AU)
Heliocentric Speed 34,100 miles per hour
Distance from Jupiter 690,529,800 miles
Round Trip Light Time 52 minutes, 26 seconds
SPECIAL TOPICS
1. As of February 27, 1992, a total of 7346 real-time commands have been
transmitted to Galileo since Launch. Of these, 2698 have been pre-planned in
the sequence design and 4648 were not. In the past week, 77 real time commands
were transmitted; 48 were pre-planned in the sequence design and 29 were not.
In addition, 3486 mini-sequence commands have been transmitted since March
1991; (1235 were pre-planned and 2251 were not). In the past week, 310
mini-sequence commands were transmitted. Major command activities this week
included commands to: open the Star Scanner (SS) shutter and reacquire
celestial reference, uplink and verify Cooling Turn No. 5 sequence memory load,
clear the spun critical controller (CRC) status register and telemetry
indicator, clear the AACS fault protection high water mark array, turn off the
400N engine heater, readout the Solid-State Imaging (SSI) memory, and reset
the command loss timer.
2. The Cool Turn No. 5 activities are scheduled from February 24 to March 6.
The spacecraft bus cool down period started on February 24 and will continue
until March 2. The cooling turn will be performed on March 2 and will be at
the cooling attitude for approximately 50 hours. The spacecraft turn back from
the cooling attitude is scheduled for March 5. The sun gate and wobble ID data
collection is scheduled during the March 5-6 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
|
| 560.608 | Updates - February 27 to March 2 | VERGA::KLAES | All the Universe, or nothing! | Thu Mar 05 1992 12:12 | 109 |
| Article: 409
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 02/27/92
Date: 27 Feb 92 20:57:46 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 27, 1992
The Galileo Spacecraft appears to be operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps. In accordance with the
Cooling Turning No. 5 mini-sequence, we are operating in a S-band TWTA low
power mode and have not been able to consistently process telemetry since
Monday afternoon, as expected.
Yesterday, no Spacecraft activity was scheduled. We were able for periods
of time up to 1 hour 48 minutes to maintain lock and process some telemetry.
Tracking was scheduled over DSS-14 (Goldstone 70 meter antenna).
Today, February 27, no Spacecraft activity is scheduled. The pre-cool
portion of Cooling Turn No. 5 is ongoing and will continue through March 2.
Tracking is ongoing over DSS-14, and we are locking up and processing some
telemetry for brief periods of time.
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 417
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/28/92
Date: 28 Feb 92 22:31:10 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 28, 1992
The Galileo Spacecraft appears to be operating normally in the dual-spin
mode and transmitting coded telemetry at 10 bps. In accordance with the
Cooling Turning No. 5 mini-sequence, we are operating in a S-band TWTA low
power mode and have not been able to consistently process telemetry since
Monday afternoon, as expected.
Yesterday, no Spacecraft activity was scheduled. We were able for short
periods of time to maintain lock and process some telemetry. Tracking was
scheduled over DSS-14 (Goldtone 70 meter antenna).
Today, February 28, no Spacecraft activity is scheduled. The pre-cool
portion of Cooling Turn No. 5 is ongoing and will continue through March 2.
Tracking is scheduled over DSS-43 (Canberra 70 meter antenna).
Over the weekend, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 437
From: johnson@kelvin.jpl.nasa.gov (Glenn Johnson)
Newsgroups: sci.space.news
Subject: Galileo Update - 3/2/92
Date: 3 Mar 92 06:00:21 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from William O'Neil, Galileo Project Manager
Galileo Spacecraft Daily Report
Monday, March 2, 1992
1. The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps (bits per second).
2. Over the weekend, no Spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canaberra 70 m antenna).
3. Today, March 2, the cooling turn to a 165 degree off sun attitude is
scheduled for this afternoon. Loss of carrier downlink is expected about
1:10 PST during the maneuver to the cooling turn attitude. The Spacecraft
will remain at the cooling turn attitude for approximately 50 hours.
Tracking is scheduled over DSS-14 and DSS-63 (Goldstone and Madrid 70 m
antennas).
4. Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled
over DSS-63 and DSS-14. Coverage is required as a precautionary measure to
assure the earliest possible warning of a Spacecraft problem since we will
not have telemetry data at attitude; no problems are expected.
*************************************************************************
Glenn Johnson
johnson@kelvin.jpl.nasa.gov
|
| 560.609 | Updates - March 3-6 | VERGA::KLAES | All the Universe, or nothing! | Wed Mar 11 1992 15:37 | 266 |
| Article: 474
From: gjohnson@cco.caltech.edu (Glenn Stanley Johnson)
Newsgroups: sci.space.news
Subject: Galileo Update - 3/3/92
Date: 9 Mar 92 04:03:38 GMT
Sender: news@cco.caltech.edu
Organization: California Institute of Technology, Pasadena
Forwarded from William O'Neil, Galileo Project Manager
Galileo Spacecraft Daily Report
Tuesday, March 3, 1992
1. The Galileo Spacecraft appears to be operating normally in the
all-spin mode and transmitting coded telemetry at 10 bps.
2. Yesterday, the cooling turn to a 165 degree off sun attitude was
performed. Loss of carrier downlink occurred, as expected, at 1:14
p.m. during the maneuver to the cooling turn attitude.
3. Today, March 3, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-63 (Madrid 70 m antenna) and DSS-14 (Goldstone 70 m
antenna). Coverage is required as a precautionary measure to assure
the earliest possible warning of a Spacecraft problem since we do not
have telemetry data at the cooling attitude; no problems are expected.
4. Tomorrow, the sequence controlled sun acquisition to a 5 degree
off sun attitude is scheduled to start at approximately 4:56 p.m.
Downlink telemetry is expected to be reacquired at approximately 6:19
p.m. with the sun acquisition completing at 6:58 p.m. Tracking is
scheduled over DSS-63, DSS-14, and DSS-43 (Canabara 70 m antenna).
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
Article: 467
From: gjohnson@cco.caltech.edu (Glenn Stanley Johnson)
Newsgroups: sci.space.news
Subject: Galileo Update - 3/4/92
Date: 9 Mar 92 04:06:01 GMT
Sender: news@cco.caltech.edu
Organization: California Institute of Technology, Pasadena
Forwarded from Neal Ausman
Galileo Spacecraft Daily Report
Wednesday, March 4, 1992
1. The Galileo Spacecraft appears to be operating normally in the all-
spin mode and transmitting coded telemetry at 10 bps (bits per second).
2. Yesterday, no Spacecraft activity was scheduled. Tracking was
scheduled over DSS-63 (Madrid 70 m antenna) and DSS-14 (Goldstone 70 m
antenna). Coverage was required as a precautionary measure to assure
the earliest possible warning of a Spacecraft problem since we do not
have telemetry data at the cooling attitude.
3. Today, March 4, the sequence controlled sun acquisition to a 5
degree off-sun attitude is scheduled to start at approximately 4:56
p.m. Downlink telemetry is expected to be reacquired at approximately
6:19 p.m. with the sun acquisition completing at 6:58 p.m. Tracking is
scheduled over DSS-63, DSS-14, and DSS- 43 (Canabera 70 m antenna).
4. Tomorrow, real time commands are scheduled to checkout the Star
Scanner (SS) and reacquire celestial reference along with collecting
wobble ID data. Tracking is scheduled over DSS-63, DSS-14, and DSS-43.
********************************************************************
Glenn S. Johnson, NASA's Jet Propulsion Laboratory
Internet: johnson@kelvin.jpl.nasa.gov, gjohnson@coil.cco.caltech.edu
X.400:(C:USA, ADMD:TELEMAIL, PRMD:NASAMAIL, O:NASA, UN:GSJOHNSON)
SPAN: JPLLSI::GJOHNSON
Article: 472
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/05/92
Date: 9 Mar 92 12:16:17 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
March 5, 1992
The Galileo spacecraft is 465 million kilometers (289 million
miles) from Earth, and 334 million kilometers from the Sun.
Round-trip communication time is 51 minutes, 35 seconds. Its speed in
solar orbit is 15.3 kilometers per second or 34,318 mph, gradually
rising as the spacecraft comes in from the asteroid belt towards Earth
and the Sun.
The cooling turn in Galileo's fifth thermal cycle (to free the
high-gain antenna) concluded Wednesday night. Sun-gate telemetry
indicates that no antenna ribs were released in this turn. The next
warming turn is scheduled for March 19-21. The spacecraft is operating
normally, transmitting coded telemetry at 10 bits per second.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 470
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/06/92
Date: 9 Mar 92 12:17:59 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
February 28 - March 5, 1992
SPACECRAFT
1. The pre-cool portion of the Cooling Turn No. 5 was completed on March 2.
The spacecraft bus cool down behaved similar to Cooling Turn No. 4. The turn
to 165 degrees off sun was initiated on March 2 at 2011 UTC. The spacecraft
downlink carrier was lost at 2114 UTC (see Special Topic No. 2).
2. On March 5, after approximately 50 hours at the cooling attitude, the
spacecraft was commanded back to a 5 degree off sun attitude. Due to ground
station receiver problems at DSS-43 (Canberra 70 meter antenna), the spacecraft
downlink carrier was not acquired until 0253 UTC (about 1 hour later than
expected) and subsequently downlink telemetry was not processed until 0301 UTC.
Additionally, when the spacecraft telemetry was processed, there were no
engineering units corresponding to the Data Numbers (DN) for the engineering
channels. The MTS No. 1 was loaded with the previous cold start database and
placed on-line to correct the problem. The turn completed at approximately
0258 UTC as predicted. After the sun acquisition, sun gate data was collected
to determine if an antenna rib is still obscuring the sun gate signal. Data
analysis indicates that the sun gate is still obscured, indicating no ribs
released (see Special Topic No. 2).
3. On March 5, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
4. On March 5, as part of Cooling Turn No. 5, commands were sent to checkout
the Star Scanner (SS) shutter. This activity is performed after each HGA (High
Gain Antenna) thermal turn as a precaution to protect the star scanner from
seeing bright particles which could have been released if the HGA ribs released
(see Special Topic No. 2).
5. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 3 DN and reads 17.1 volts. The AC measurement decreased
1 DN and reads 43.9 volts. All other power telemetry and subsystem telemetry
appear normal.
6. The Spacecraft status as of March 5, 1992, was as follows:
a) System Power Margin - 29 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.11 rpm/Acquisition Sensor
d) Spacecraft Attitude is Sun pointed; Sun point angle
is approximately 5 degrees (Leading)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EPD, MAG, UVS, DDS, EUV, & HIC
are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 244 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Warming Turn No. 6 mini-sequence was approved for generation by the
Project on March 3, 1992. The Warming Turn No. 6 activities are scheduled
from March 19 to March 24.
2. The final EE-5 (Earth-Earth 5) sequence and command generation product
was approved for transmission by the Project on March 5, 1992. This sequence
controls spacecraft activities from March 10, 1992 to April 27, 1992.
3. The EE-6/7 final cruise plan was approved by the Project on March 5, 1992.
This sequence controls spacecraft activities from May 11, 1992 to November 23,
1992.
TRAJECTORY
As of noon Thursday, March 5, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 288,707,800 miles (3.11 AU)
Distance from Sun 207,655,000 miles (2.24 AU)
Heliocentric Speed 34,300 miles per hour
Distance from Jupiter 691,208,600 miles
Round Trip Light Time 51 minutes, 44 seconds
SPECIAL TOPICS
1. As of March 5, 1992, a total of 7389 real-time commands have been
transmitted to Galileo since Launch. Of these, 2741 have been pre-planned in
the sequence design and 4648 were not. In the past week, 43 real time commands
were transmitted; 43 were pre-planned in the sequence design. In addition, 3486
mini-sequence commands have been transmitted since March 1991; (1235 were
pre-planned and 2251 were not). In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to:
reset the command loss timer, and checkout the Star Scanner (SS) shutter.
2. The Cool Turn No. 5 activities are scheduled from February 24 to March 6.
The spacecraft bus cool down period started on February 24 and continued until
March 2. The cooling turn was performed on March 2 and the spacecraft was at
the cooling attitude for approximately 50 hours. The spacecraft turn back from
the cooling attitude occurred on March 5. The sun gate and wobble ID data
collection is scheduled during the March 5-6 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 473
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 03/06/92
Date: 9 Mar 92 12:21:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 6, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, real time commands were sent to checkout the Star Scanner (SS)
and reacquire celestial reference along with collecting wobble ID data.
Commanding was delayed due to high power (100KW) transmitter problems at
DSS-43 (Canberra 70 meter antenna); commands were sent using the low power
(20KW) transmitter and successfully received.
Today, March 6, the uplink of the EE-5 (Earth-Earth 5) sequence memory
load is scheduled. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna)
and DSS-43.
Over the weekend, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
|
| 560.610 | Russians to help out (?) | CARROL::LEPAGE | Jinky rules!!! | Mon Mar 16 1992 14:35 | 12 |
|
Well, I heard this through the grapevine and it looks interesting.
The option of using clusters of deep space tracking antennae in the
former Soviet Union is being examined so that Galileo can transmit at
higher rates in the event the HGA can not be deployed. It would cost
the U.S. relatively little and the Russians could use the hard currency
(and since these tracking antennae are sitting idle at the moment and
will be under utilised during the MARS 1994 mission, they will be
available for the task).
Drew
|
| 560.611 | Updates - March 9-13 | VERGA::KLAES | All the Universe, or nothing! | Mon Mar 16 1992 20:37 | 356 |
| Article: 477
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/09/92
Date: 10 Mar 92 06:54:59 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 9, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps. Over the weekend, no Spacecraft
activity was scheduled. Tracking was scheduled over DSS-43 (Canberra 70 meter
antenna).
Today, March 9, the EE-5 (Earth-Earth 5) sequence memory load is scheduled
to begin. Tracking is scheduled over DSS-43.
Tomorrow, the routine RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance activity along with routine science MROs are scheduled
over DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 481
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/10/92
Date: 11 Mar 92 03:20:09 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 10, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the EE-5 (Earth-Earth 5) sequence when active. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna).
Today, March 10, the routine RPM (Retro Propulsion Module) 10-Newton
thruster "flushing" maintenance activity, routine science Memory Readouts
(MROs), and a science turn (SITURN) to a 9 degree off Earth pointed attitude
are scheduled over DSS-14 (Goldstone 70 meter antenna).
Tomorrow, Radio Frequency Subsystem (RFS) tests are scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 483
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/11/92
Date: 12 Mar 92 03:09:16 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 11, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the routine RPM (Retro Propulsion Module) 10-Newton thruster
flushing maintenance activity, routine science Memory Readouts (MROs), and a
science turn (SITURN) to a 9 degree off Earth pointed attitude were performed
over DSS-14 (Goldstone 70 meter antenna).
Today, March 11, Radio Frequency Subsystem (RFS) tests are scheduled over
DSS-14.
Tomorrow, no Spacecraft activity is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 496
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 03/11/92
Date: 12 Mar 92 07:51:15 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
March 11, 1992
The Galileo spacecraft is more than 458 million kilometers
(almost 285 million miles) from Earth, a distance that is decreasing
by about a million kilometers each day. The spacecraft is 333 million
kilometers from the Sun, and its speed in solar orbit is 15.4
kilometers per second, about 34,500 mph.
The spacecraft is operating normally under computer sequence
control; the current operating sequence was transmitted last week,
took effect Monday (March 9) and will control spacecraft activities
until April 27. This week the spacecraft is conducting a planned
series of engineering tests and routine maintenance activities, as
well as the usual cruise science observations.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 498
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/12/92
Date: 13 Mar 92 02:41:39 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 12, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, a Radio Frequency Subsystem (RFS) test was performed over
DSS-14 (Goldstone 70 meter antenna).
Today, March 12, 1992, no Spacecraft activity or tracking is scheduled.
Tomorrow, a routine Dust instrument cruise science MRO (Memory Readout)
is scheduled along with a Radio Frequency Subsystem (RFS) test. Tracking is
scheduled over DSS-14 and DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 512
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/13/92
Date: 14 Mar 92 03:29:26 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
March 6 - 12, 1992
SPACECRAFT
1. On March 6, as part of Cooling Turn No. 5, commands were sent to open the
Star Scanner (SS) shutter and to reacquire celestial reference. Commanding was
delayed for approximately one hour due to high power (1OOkw) transmitter
problems at DSS-43 (Canberra 70 meter antenna); commands were sent using the
Low power (20kw) transmitter and were successfully received. Additionally,
the AACS (Attitude and Articulation Control Subsystem) gyro-based wobble data
was collected with the spacecraft in the dual-spin mode. Analysis of the data
indicates no change in wobble as a result of the cooling turn corroborating the
sun gate obscuration data. After the turn, Probe shelf temperatures (T1)
reached 27.3 degrees C which was approximately 2 degrees above predicts but
well below the maximum allowable temperature of 35 degrees C.
2. On March 6, the EE-5 (Earth-Earth 5) sequence memory load was uplinked
to the spacecraft. Additionally, Memory Readout (MRO) commands were sent to
verify the sequence was loaded correctly. The sequence was loaded on the
spacecraft without incident using the low power (20kw) transmitter at DSS-43.
3. On March 8, two more unexpected CDS (Command Data Subsystem) lock change
counts were observed over DSS-43 during a period of transmitter problems. The
high power transmitter tripped off on March 7 at 2208 UTC and the station
switched to the low power transmitter at 2230 UTC. The CDU (Command Detector
Unit) lock change counts were observed on March 8 at 0032 UTC. The spacecraft
did not receive any commands as a result of this anomaly.
4. Over the weekend, the AC/DC bus imbalance readings changed significantly.
At the end of the DSS-43 track on Saturday, the AC bus imbalance was reading
223 DN (44.3 volts) which has been its normal reading plus or minus 5 DN over
the last two years. At the beginning of the DSS-43 track on Sunday, the AC
bus imbalance was reading 13 DN (3.1 volts) a change of 210 DN. Additionally,
the inverter current decreased by 3 DN and the shunt current increased
correspondingly. (See Special Topic No. 2.)
5. On March 9, a NO-OP command was sent to reset the command loss timer to
336 hours, its planned value for this mission phase.
6. Solid-State Imaging (SSI) instrument routine Memory Readouts (MROs) were
performed on March 10 to verify the health status of the SSI. The instrument
checkout was nominal.
7. On March 10, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect information for the gravitational
red shift experiment.
8. On March 10, cruise science memory readouts were performed for the Extreme
Ultraviolet Spectrometer (EUV) and Magnetometer (MAG) instrument.
9. On March 10, the periodic RPM (Retro Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed; 10 of the 12 thrusters were
flushed during the exercise. The P-thrusters were not flushed because they
were used to perform science turn (SITURN) activities.
10. On March 10, the Earth vector was updated and a science turn (SITURN) was
commanded which oriented the spacecraft to a 9 degree off earth pointed
attitude (Earth leading) for the purpose of checking out the S-Band and X-Band
of the HGA (High Gain Antenna) in the event of a successful deployment of the
antenna. The turn was accomplished using the P-thrusters; spacecraft
performance throughout the turn was normal.
11. On March 11, a delta Differential One-way Range (DOR) was performed over
DSS-14 (Goldtone 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
12. On March 11, a Command Detector Unit Signal to Noise Ratio (CDUSNR) test
along with a Radio Frequency Subsystem Tracking Loop Capacitor (RFSTLC) test
were performed. The CDUSNR test was unsuccessful due to a Command Processor
Assembly (CPA) problem at DSS-14.
13. The Spacecraft status as of March 12, 1992, was as follows:
a) System Power Margin - 36 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is Earth pointed; Earth point
angle is approximately 8 degrees (Leading)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EPD, MAG, UVS, DDS, EUV, & HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 336 hours
Time To Initiation - 263 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL: None
GDS (Ground Data Systems):
1. Two brief demonstration passes of the Type C/String 5 TPA (Telemetry
Processing Assemble) were conducted with DSS-14. The demonstration passes
were conducted in parallel with flight operations support using a Type A TPA.
A bit-level comparison of approximately 25% of the data showed no deviation
from the data delivered to the MTS with the Type A TPA and there was no data
loss. The first day's pass required an hour to lock up but on the second
day's pass lock-up time was nominal. A longer pass is planned for the week
of March 16 for additional testing and to increase the Project's confidence
in the Type C/String 5 TPA before approving its operational use.
TRAJECTORY
As of noon Thursday, March 12, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 284,187,400 miles (3.06 AU)
Distance from Sun 206,723,800 miles (2.23 AU)
Heliocentric Speed 34,600 miles per hour
Distance from Jupiter 691,743,500 miles
Round Trip Light Time 50 minutes, 56 seconds
SPECIAL TOPICS
1. As of March 12, 1992, a total of 7437 real-time commands have been
transmitted to Galileo since Launch. Of these, 2789 have been pre-planned in
the sequence design and 4648 were not. In the past week, 48 real time commands
were transmitted; 48 were pre-planned in the sequence design. In addition,
3486 mini-sequence commands have been transmitted since March 1991; (1235 were
pre-planned and 2251 were not). In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to:
open the Star Scanner (SS) shutter and reacquire celestial reference, load and
verify the EE-5 sequence memory load and, reset the command loss timer.
2. During a DSN (Deep Space Network) non-tracking period between March 7 and
March 8, 1992, the AC bus imbalance measurement changed from 223DN (44.3 volts)
to 13DN (3.1 volts). Additionally, a steady-state power change of about 3.5
watts was observed. The AC bus imbalance measurement has been relatively
stable until this change since its on-set in 1989. This recent change is
consistent with the spin bearing brush debris model. Work in progress
includes: analytical modeling of the sensor/circuitry to explain the recent
measurement reading; testing to characterize the sensor hardware over a wide
range of leakage resistances; re-reviewing the 2.4khz inverter current
telemetry history; re-evaluating the maintenance mode bias strategy for the
EPD (Energetic Particles Detector) and HIC (Heavy Ion Counter) detectors; and
investigating use of the EPD detector bias circuit to independently verify the
current bus imbalance condition.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
Article: 514
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 03/13/92
Date: 14 Mar 92 05:10:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 13, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, no Spacecraft activity or tracking was scheduled.
Today, March 13, 1992, a routine Dust instrument cruise science MRO
(Memory Readout) is being performed along with a Radio Frequency Subsystem
(RFS) test. Tracking is scheduled over DSS-14 (Goldtone 70 meter antenna) and
DSS-43 (Canberra 70 meter antenna).
Over the weekend, no Spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In the middle of difficulty
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | lies opportunity --
|_____|/ |_|/ |_____|/ | Albert Einstein
|
| 560.612 | GALILEO heliocentric orbital elements | VERGA::KLAES | All the Universe, or nothing! | Tue Mar 17 1992 20:07 | 214 |
| Article: 21056
From: higgins@fnalo.fnal.gov (Bill Higgins-- Beam Jockey)
Newsgroups: sci.astro,sci.space
Subject: I've got 'em! (was Re: Galileo heliocentric orbital elements)
Date: 17 Mar 92 01:36:44 GMT
Sender: news@fnnews.fnal.gov
Organization: Fermi National Accelerator Laboratory
In article <1992Mar16.173204.27048@kakwa.ucs.ualberta.ca>,
martin@space.ualberta.ca (Martin Connors) writes:
> I have had a couple of replies about this. There seems to be
> interest in optically viewing Galileo...apparently there was a
> sighting last time around. I do not know too much about this.
Yes, there was a guy who managed to see Galileo in a telescope. Sorry,
don't have a reference. *Sky and Telescope* perhaps, early 1991?
> There was also an allegation that Galileo's orbital elements are "secret"
> because JPL does not want publicity or "interference" due to its RTG's
> coming "back".
Never heard this, and I find it implausible. Given that the arrival
dates at Gaspra, Earth, and Jupiter are public, it's hard to see how
they could do more than introduce a little uncertainty into the figures.
Anyway, a friend at JPL has provided the "official" story. If you're
looking for proof of a coverup, I guess you can check for yourself on
December 8th. (-: Here you go:
==============[begin JPL official announcement]=================
INTERPLANETARY ORBITAL ELEMENTS FOR GALILEO
Galileo was launched on October 18, 1989, on a six-year trajectory
that will take it to Jupiter. On the way, Galileo's flight path takes
it on a flyby of Venus, then of Earth, then by the asteroid Gaspra,
followed by another Earth flyby and an encounter with the asteroid
Ida. Several months before Jupiter arrival, Galileo will release a
probe which will descend into the Jovian atmosphere. The main Galileo
orbiter will undertake a complex oribtal tour at Jupiter including
flybys of all of the giant planet's major moons.
The following are classic orbital elements for the Galileo spacecraft,
as provided in December 1990 by the Galileo Navigational Team at the
Jet Propulsion Laboratory. The coordinate system is Earth Mean
Ecliptic, 1950 Equinox.
Dates (in year/month/day format) and times (in 24-hour format) are
both in Universal Time (UTC), also known as Greenwich Mean Time (GMT).
All elements apply to the mated Galileo orbiter and probe, with the
exception of the final three sets of elements which are marked as
being for the probe only. The elements for the orbiter after probe
separation (July 17, 1995) are not listed but will be posted when
available from the Galileo Project.
_____
LAUNCH
Valid from 89/10/19 01:29
to 89/10/26 01:55
Epoch 89/10/19 01:29
Central body Earth
Semi-major axis (km) -2.584E4
Eccentricity 1.26
Inclination (deg) 54.9
Longitude of ascending node (deg) 157.2
Argument of periapsis (deg) -1.1
Mean anomaly 36.4
EARTH-VENUS
Valid from 89/10/26 01:55
to 90/02/05 15:20
Epoch 89/10/26 01:55
Central body Sun
Semi-major axis (km) 1.245E8
Eccentricity 0.20
Inclination (deg) 4.3
Longitude of ascending node (deg) 24.7
Argument of periapsis (deg) -175.3
Mean anomaly -177.3
VENUS FLYBY
Valid from 90/02/05 15:20
to 90/02/14 20:56
Epoch 90/02/10 05:59
Central body Venus
Semi-major axis (km) -8.555E3
Eccentricity 3.59
Inclination (deg) 134.9
Longitude of ascending node (deg) -70.6
Argument of periapsis (deg) -109.1
Mean anomaly 0.0
VENUS-EARTH
Valid from 90/02/14 20:56
to 90/12/05 15:47
Epoch 90/02/14 20:56
Central body Sun
Semi-major axis (km) 1.479E8
Eccentricity 0.29
Inclination (deg) 3.4
Longitude of ascending node (deg) 76.0
Argument of periapsis (deg) 106.3
Mean anomaly -10.3
EARTH 1 FLYBY
Valid from 90/12/05 15:47
to 90/12/12 01:24
Epoch 90/12/08 20:35
Central body Earth
Semi-major axis (km) -4.977E3
Eccentricity 2.47
Inclination (deg) 142.2
Longitude of ascending node (deg) 71.8
Argument of periapsis (deg) 95.9
Mean anomaly 0.0
EARTH-GASPRA
Valid from 90/12/12 01:24
to 91/10/29 22:49
Epoch 90/12/12 01:24
Central body Sun
Semi-major axis (km) 2.375E8
Eccentricity 0.43
Inclination (deg) 4.5
Longitude of ascending node (deg) -104.1
Argument of periapsis (deg) -136.8
Mean anomaly -14.9
GASPRA-EARTH
Valid from 91/10/29 22:49
to 92/12/05 10:09
Epoch 91/10/29 22:49
Central body Sun
Semi-major axis (km) 2.376E8
Eccentricity 0.43
Inclination (deg) 4.6
Longitude of ascending node (deg) -103.9
Argument of periapsis (deg) -137.1
Mean anomaly 143.8
EARTH 2 FLYBY
Valid from 92/12/05 10:09
to 92/12/11 21:03
Epoch 92/12/08 15:35
Central body Earth
Semi-major axis (km) -5.059E3
Eccentricity 2.32
Inclination (deg) 161.1
Longitude of ascending node (deg) 155.9
Argument of periapsis (deg) -136.7
Mean anomaly 0.0
EARTH-IDA
Valid from 92/12/11 21:03
to 93/08/28 16:35
Epoch 92/12/11 21:03
Central body Sun
Semi-major axis (km) 4.683E8
Eccentricity 0.69
Inclination (deg) 1.5
Longitude of ascending node (deg) -104.1
Argument of periapsis (deg) -173.5
Mean anomaly -0.3
IDA-JUPITER (PROBE ONLY)
Valid from 93/08/28 16:35
to 95/09/14 03:12
Epoch 93/08/28 16:35
Central body Sun
Semi-major axis (km) 4.693E8
Eccentricity 0.69
Inclination (deg) 1.6
Longitude of ascending node (deg) -105.3
Argument of periapsis (deg) -172.5
Mean anomaly 45.7
JUPITER APPROACH (PROBE ONLY)
Valid from 95/09/14 03:12
to 95/12/07 22:04
Epoch 95/09/14 03:12
Central body Jupiter
Semi-major axis (km) -4.136E6
Eccentricity 1.02
Inclination (deg) 8.0
Longitude of ascending node (deg) 27.4
Argument of periapsis (deg) 132.3
Mean anomaly -561.7
PROBE ENTRY
Valid from 95/12/07 22:04
to 95/12/07 22:04
Epoch 95/12/07 22:04
Central body Jupiter
Semi-major axis (km) -2.274E6
Eccentricity 1.03
Inclination (deg) 8.2
Longitude of ascending node (deg) 25.5
Argument of periapsis (deg) 134.8
Mean anomaly 0.0
==============[end JPL official announcement]=================
Note that Galileo has not committed to the Ida encounter yet. That
decision will be made next July.
What Fermi did under a stadium Bill Higgins
Da deuteron, ron, ron, da deuteron ron Fermi National Accelerator Laboratory
She did with heavy water and palladium Bitnet: HIGGINS@FNALB.BITNET
Da deuteron, ron, ron, da deuteron ron SPAN/Hepnet: 43011::HIGGINS
--W. Skeffington Higgins, Internet: HIGGINS@FNAL.FNAL.GOV
"Fusion Girl," 1989
|
| 560.613 | Updates - March 16-23 | VERGA::KLAES | All the Universe, or nothing! | Mon Mar 23 1992 22:32 | 388 |
| Article: 527
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/16/92
Date: 17 Mar 92 02:24:35 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 16, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps (bits/second).
Over the weekend, no Spacecraft activity or tracking was scheduled.
Today, March 16, 1992, the uplink of the Warming Turn No. 6 sequence
memory load is being performed. Tracking is scheduled over DSS-14 (Goldstone
70 meter antenna).
Tomorrow, the Solid State Imaging (SSI) instrument is scheduled to be
turned off along with the turning on the Ultraviolet Spectrometer (UVS)
supplemental heater.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 531
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/17/92
Date: 18 Mar 92 03:51:57 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 17, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the uplink of the Warming Turn No. 6 sequence memory load was
performed. Tracking was scheduled over DSS-14 (Goldstone 70 meter antenna).
Today, March 17, 1992, the Solid State Imaging (SSI) instrument is
scheduled to be turned off along with turning on the Ultraviolet Spectrometer
(UVS) supplemental heater. Tracking is scheduled over DSS-14 and DSS-43
(Canberra 70 meter antenna).
Tomorrow, no Spacecraft activity is planned. Tracking is scheduled over
DSS-63 (Madrid 70 meter antenna) and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 538
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/18/92
Date: 19 Mar 92 03:20:04 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 18, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the Solid State Imaging (SSI) instrument was turned off and
its replacement heater turned on. Also, the Ultraviolet Spectrometer (UVS)
supplemental heater was turned on. Tracking was performed over DSS-14
(Goldtone 70 meter antenna) and DSS-43 (Canberra 70 meter antenna).
Today, March 18, 1992, no Spacecraft activity is planned. Tracking is
scheduled over DSS-63 (Madrid 70 meter antenna) and DSS-14.
Tomorrow, Warming Turn #6 to a 45 degree off sun attitude is scheduled.
Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 550
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/19/92
Date: 20 Mar 92 02:52:12 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 19, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, no Spacecraft activity was planned. Tracking was scheduled
over DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, March 19, 1992, Warming Turn No. 6 to a 45 degree off-sun attitude
is scheduled to begin at approximately 10:25 A.M.. Loss of downlink telemetry
is expected to occur at approximately 10:50 A.M. during the maneuver to the
warming attitude. The Spacecraft will remain at the warming attitude for
approximately 48 hours. Tracking is scheduled over DSS-14.
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-14 and DSS-43 (Canberra 70 meter antenna). Coverage is required as a
precautionary measure to assure the earliest possible warning of a Spacecraft
problem since telemetry data at the warming attitude is not expected.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 551
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 03/19/92
Date: 20 Mar 92 02:53:41 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
March 19, 1992
The Galileo spacecraft is 449 million kilometers (279 million
miles) from Earth, and 331 million kilometers (206 million miles) from
the Sun. Its speed in solar orbit is 15.589 kilometers per second, or
34,871 mph.
The spacecraft is operating normally, transmitting coded
telemetry at 10 bits per second. Today it turns its spin axis 45
degrees away from the Sun for the warming-turn portion of the sixth
temperature cycle in the program to free the high-gain antenna. It
will remain in this attitude for two days. The next cooling turn is
planned for mid-April.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 555
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #3 - 03/19/92
Date: 20 Mar 92 07:09:29 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
March 13 - 19, 1992
SPACECRAFT
1. On March 13, routine Dust Detector (DDS) Memory Readouts (MROs) were
performed. The first of three redundant MROs was lost due to a hardware
problem (universal counter) at DSS-14 (Goldtone 70 meter antenna) which
delayed the Acquisition of Signal (AOS).
2. On March 13, a Radio Frequency Subsystem Automatic Gain Control (RFSAGC)
test was performed using LGA-1 (Low Gain Antenna #1) over DSS-14. The test
indicated there has been no observed change in spacecraft receiver threshold
since launch.
3. On March 13, a delta Differenced One-way Range (DOR) was performed over
DSS-14 and DSS-43 (Canberra 70 meter antenna). Initial results indicate that
the delta DOR was successfully performed.
4. On March 16, the Warming Turn No. 6 sequence memory load was sent to the
spacecraft. Additionally, Memory Readout commands were sent to verify the
sequence was loaded correctly. The sequence was loaded on the spacecraft
without incident (see Special Topic No. 2).
5. On March 16, Delayed Action Commands (DACs) were uplinked to turn the
Photometric Calibration Target (PCT) heater No. 2 (8 watt) off and on during
the Warming Turn No. 6 sequence on March 19 in order to maintain power margins.
6. On March 16, commands were sent to update the system fault protection such
that if spacecraft safing is invoked, the Plasma Wave Subsystem (PWS)
supplemental heater is powered on.
7. On March 16, commands were sent to checkout the Energetic Particle Detector
(EPD) LEMMS A detector bias because of the recent AC bus imbalance reading
change from 223DN (44.3 volts) to 13DN (3.1 volts). The results of the test
showed that there is some bias applied to the detectors. No near-term detector
bias strategy changes are expected.
8. On March 17, commands were sent to turn off the Solid State Imaging (SSI)
instrument and turn on the SSI replacement heater in accordance with the SSI
usage strategy of powering the instrument off except for cold turns and imaging
periods. Additionally, on the following day, the Ultraviolet Spectrometer
(UVS) supplemental heater was turned on to maintain adequate temperature
margins on the scan platform.
9. During the period of March 17 through March 18, a navigation cycle was
performed. The navigation cycle provided near-continuous acquisition of
two-way Doppler and ranging data during four consecutive passes of the
spacecraft over DSS-14, DSS-43, DSS-63 (Madrid 70 meter antenna), and then
back to DSS-14. Initial results indicated that the navigation cycle was
successfully performed.
10. On March 19, the Warming Turn No. 6 sequence memory load went active.
The turn to a 45-degree off-sun attitude commenced at approximately 1825 UTC.
The downlink telemetry was lost at 1908 UTC and the turn completed at
approximately 1914 UTC (see Special Topic No. 2).
11. The AC/DC bus imbalance measurements exhibited some minor change. The DC
measurement decreased 4DN and reads 18.6 volts. The AC measurement dropped
slightly and reads 2.9 volts.
12. The Spacecraft status as of 1600 PST March 19, 1992, could not be
determined by real-time telemetry because the spacecraft was at the warming
attitude with no downlink telemetry data being received. The following
information is taken from previous spacecraft performance and predicts.
a) System Power Margin - 26 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 45 degrees off sun (lagging)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EPD, MAG, UVS, DDS, EUV, & HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 336 hours
Time To Initiation - 290 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Warming Turn No. 6 mini-sequence was approved for transmission by the
Project on March 13, 1992. The Warming Turn No. 6 activities are scheduled
from March 19 to March 24.
TRAJECTORY
As of noon Thursday, March 19, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 279,082,000 miles (3.00 AU)
Distance from Sun 205,679,000 miles (2.21 AU)
Heliocentric Speed 34,900 miles per hour
Distance from Jupiter 692,133,000 miles
Round Trip Light Time 50 minutes, 2 seconds
SPECIAL TOPICS
1. As of March 19, 1992, a total of 7600 real-time commands have been
transmitted to Galileo since Launch. Of these, 2849 have been pre-planned in
the sequence design and 4751 were not. In the past week, 163 real time
commands were transmitted; 60 were pre-planned in the sequence design and 103
were not. In addition, 3567 mini-sequence commands have been transmitted
since March 1991; (1316 were pre-planned and 2251 were not). In the past week,
81 mini-sequence commands were transmitted. Major command activities this
week included commands to: uplink and verify the Warming Turn No. 6 sequence
memory load, turn the Photometric Calibration Target (PCT) heater No. 2 off
and on, update the system fault protection parameters, checkout the Energetic
Particle Detector (EPD) LEMMS A detector bias, turn off the Solid State
Imaging (SSI) instrument, turn on the SSI replacement heater, and turn the
Ultraviolet Spectrometer (UVS) supplemental heater on.
2. The Warming Turn No. 6 activities are scheduled from March 19 through
March 24. The warming turn will be performed on March 19 and the spacecraft
will remain at the warming attitude for approximately 48 hours. The spacecraft
turn back from the warming attitude will be performed on March 21. The sun
gate and wobble ID data collection is scheduled during the March 21-24 time
period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 559
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/20/92
Date: 21 Mar 92 03:44:03 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 20, 1992
The Galileo Spacecraft appears to be operating normally in the all-spin
mode and transmitting coded telemetry at 10 bps.
Yesterday, Warming Turn No. 6 to a 45 degree off-sun attitude was
completed as scheduled. Loss of telemetry data occurred at approximately
11:08 A.M. during the maneuver to the warming attitude. Tracking was
scheduled over DSS-14 (Goldtone 70 meter antenna).
Today, March 20, 1992, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-14 and DSS-43 (Canberra 70 meter antenna). Coverage is
required as a precautionary measure to assure the earliest possible warning of
a Spacecraft problem since telemetry data at the warming attitude is not
expected.
Over the weekend, the Spacecraft under stored sequence control is
scheduled to turn back from the warming attitude to a 5 degree off-sun attitude
on Saturday; the sun acquisition will complete at approximately 10:29 A.M..
Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 573
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/23/92
Date: 24 Mar 92 03:08:07 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 23, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Over the weekend, the Spacecraft under stored sequence control turned
back from the warming attitude to a 5 degree off-sun attitude on Saturday; the
sun acquisition completed at approximately 10:32 A.M. and the sun gate data
indicated no change in rib position. Tracking was scheduled over DSS-14
(Goldstone 70 meter antenna).
Today, March 23, 1992, real-time commands are scheduled to checkout the
Star Scanner (SS) and reacquire celestial reference along with collecting
wobble ID data. Tracking is scheduled over DSS-14 and DSS-43 (Canberra 70
meter antenna).
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-63 (Madrid 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
|
| 560.614 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Tue Mar 24 1992 13:57 | 10 |
| I wish someone at JPL would be more forthcomming with information.
We now have the 6th warming turn with no movement of the ribs.
Is there an alternate plan? How long are they going to continue this
present series of attempts? Has their prognosis changed?
This one is giving me heartaches.
Tony
|
| 560.615 | Par for the course | HPSRAD::DZEKEVICH | | Wed Mar 25 1992 13:53 | 7 |
| Yeah....I can see it now. They will change their reports from
"nominal" to "sub-nominal"....and go on as usual.
Only kidding....
Joe
|
| 560.616 | | HELIX::MAIEWSKI | | Wed Mar 25 1992 16:50 | 24 |
| From what I've heard, the feeling is that they have a lot of time. There's no
rush. If it is still not open within a year or 2 of arriving at Jupiter then
they might try more dangerous things like cranking the motor and trying to
brute force the thing open. For now they are satisfied with heating and cooling
to see what happens.
Also, they might be making progress even if no motion is detected. I believe
that the plan is to use heating and cooling to "walk" the ribs through the 1st
fraction of an inch. After that it should come unstuck and pop open.
Most likely the plan is to do heating and cooling only through the swing past
Earth, then move to something like a few rapid on/off engine motions, perhaps
in conjunction with heating and cooling, then try the hard engine burning crank
only if it is necessary.
Meanwhile much is being done to improve the ground facilities to get a 10 to
100 rate increase in processing by the low gain antenna.
One way or another, I'm willing to bet that we get to see pretty pictures.
Maybe not as many but enough. The important data, like the data from the
atmosphere probe, comes at lower baud rates and can be handled easily by
the low gain antenna.
George
|
| 560.617 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Wed Mar 25 1992 17:38 | 13 |
| George,
I knew about the walking business. The reports specifically state "no
change in rib position". To me, and maybe I'm wrong, this indicates
that they are having no success in their efforts at making the antenna
walk through heating and cooling cycles.
I know your feelings that they are doing as much as possible and it is
probably true, I just wish would communicate their
ideas/hopes/frustrations a little better. I've been on the edge of my
seat for almost a year with this one ....
Tony
|
| 560.618 | They're hoping to notice the final SPROING | RANGER::REITH | Jim (RANGER::) Reith - LJO2 | Wed Mar 25 1992 19:09 | 5 |
| They won't be able to detect the rib creep. They'll only notice when
one or more ribs become unstuck. They're looking at the shadow of a rib
that is arced up from a point which MIGHT be moving a tiny fraction of
an inch with each temperature cycle. The change in rib arc probably
isn't noticable in the out of focus "blocked" view they've got of it.
|
| 560.619 | | IAMNRA::SULLIVAN | Hang on, here we goooooooo! | Thu Mar 26 1992 12:54 | 0 |
| 560.620 | | IAMNRA::SULLIVAN | Hang on, here we goooooooo! | Thu Mar 26 1992 13:01 | 15 |
| > They're looking at the shadow of a rib that is arced up from a point which
> MIGHT be moving a tiny fraction of an inch with each temperature cycle.
Also, just heating and cooling could cause some rib flexing which could *appear*
to be minor rib movement, except it would change with temperature as it moved
from one extreme to the other. Until one or more let go it would be hard to have
any certainty of minor movement.
Of course, I have to wonder if these heating and cooling cycles may be jamming
the ribs even tighter into the hub... like a car stuck in sand by making
indentations under it's tires that become worse as it works back and forth
trying to get out. I guess this would be the "every silver lining has a
dark cloud" class of accessment. ;-)
-SES
|
| 560.621 | | HELIX::MAIEWSKI | | Thu Mar 26 1992 20:11 | 5 |
| Probably not. A car digs itself deeper because gravity pulls it down as
the wheels dig deeper into the ground. There is no force at work pulling the
ribs in, only the elasticity of the bent ribs pulling the top out.
George
|
| 560.622 | Updates - March 24-25 | VERGA::KLAES | All the Universe, or nothing! | Thu Mar 26 1992 20:33 | 63 |
| Article: 588
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/24/92
Date: 25 Mar 92 03:41:52 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 24, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, real-time commands were sent to checkout the Star Scanner (SS)
and reacquire celestial reference along with collecting wobble ID data.
Tracking was scheduled over DSS-14 (Goldstone 70 meter antenna) and DSS-43
(Canberra 70 meter antenna).
Today, March 24, 1992, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-63 (Madrid 70 meter antenna).
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 594
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/25/92
Date: 26 Mar 92 05:37:29 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
GALILEO STATUS REPORT
March 25, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, no Spacecraft activity was scheduled. Tracking was scheduled
over DSS-63 (Madrid 70 meter antenna).
Today, March 25, 1992, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-63.
Tomorrow, no Spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
|
| 560.623 | Update - March 27 | VERGA::KLAES | All the Universe, or nothing! | Tue Mar 31 1992 21:06 | 116 |
| Article: 617
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/27/92
Date: 28 Mar 92 06:28:08 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
March 20 - 26, 1992
SPACECRAFT
1. On March 21, as part of Warming Turn No. 6 activities, the spacecraft,
under stored sequence control, was commanded back to a 5 degree off-sun
attitude after remaining at the warming attitude for approximately 48 hours.
Downlink telemetry was received at 1821 UTC and the turn completed at 1832 UTC.
After the sun acquisition, sun gate data was collected to determine if an
antenna rib is still obscuring the sun gate signal. Data analysis indicates
that the sun gate is still obscured, confirming no rib release.
2. On March 23, as part of Warming Turn No. 6 activities, real-time commands
were sent to determine the possible presence of bright bodies in the star
scanner field of view. No evidence of bright body interference was observed.
3. On March 23, as part of Warming Turn No. 6 activities, real-time commands
were sent to open the Star Scanner (SS) shutter and to reacquire celestial
reference. Additionally, the AACS (Attitude and Articulation Control
Subsystem) gyro-based wobble data was collected. The wobble test was performed
with the spacecraft in the dual-spin mode. Analysis of the data indicates no
change in wobble as a result of the warming turn corroborating the sun gate
obscuration data.
4. On March 23, a NO-OP command was sent to reset the command loss timer to
336 hours, its planned value for this mission phase.
5. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement decreased 1 DN and reads 18.5 volts. The AC measurement remained
unchanged and reads 2.9 volts.
6. The Spacecraft status as of March 26, 1992, was as follows:
a) System Power Margin - 31 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 7 degrees off sun (lagging)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EPD, MAG, UVS, DDS, EUV, & HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 336 hours
Time To Initiation - 262 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Cooling Turn No. 6 mini-sequence was approved for generation by the
Project on March 23, 1992. The Cooling Turn No. 6 activities are scheduled
from April 6 thru April 17.
GDS (Ground Data Systems):
1. The March 1992 C5.1 software delivery activities concluded this past week
with the initial delivery of the Radio Science System's Radio Science Open-Loop
Data Validation (ROLVAL) program set. ROLVAL successfully completed its
acceptance test and delivery reviews on Thursday, March 26. ROLVAL was placed
online for operational use on March 26 on the Radio Occultation Data Analysis
(RODAN) PRIME 4050 computer system. The C5.1 deliveries, encompassing 13
program sets, 22 SCRs and 81 FRs, provide updates to capabilities needed for
Earth 2 sequence planning and sequence generation activities as well as
downlink support enhancements.
2. Multimission Verification Tests (MVTs) for the new DSN (Deep Space Network)
Command Processor Assembly (CPA) software were conducted March 19 and 24,
respectively. Both MVTs were successful.
TRAJECTORY
As of noon Thursday, March 26, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 273,421,000 miles (2.94 AU)
Distance from Sun 204,519,000 miles (2.20 AU)
Heliocentric Speed 35,200 miles per hour
Distance from Jupiter 692,377,000 miles
Round Trip Light Time 49 minutes, 2 seconds
SPECIAL TOPICS
1. As of March 26, 1992, a total of 7647 real-time commands have been
transmitted to Galileo since Launch. Of these, 2896 have been pre-planned in
the sequence design and 4751 were not. In the past week, 47 real time commands
were transmitted; 47 were pre-planned in the sequence design, none were
unplanned. In addition, 3567 mini- sequence commands have been transmitted
since March 1991; (1316 were pre-planned and 2251 were not). In the past week,
no mini-sequence commands were transmitted. Major command activities this
week included commands to: checkout and open the Star Scanner (SS) shutter and
reacquire celestial reference, and reset the command loss timer.
2. The Warming Turn No. 6 activities were scheduled from March 19 through
March 24. The warming turn was performed on March 19 and the spacecraft
remained at the warming attitude for approximately 48 hours. The spacecraft
turn back from the warming attitude was performed on March 21. The sun gate
and wobble ID data collection occurred during the March 21-24 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
|
| 560.624 | DN? | AUSSIE::GARSON | | Wed Apr 01 1992 21:52 | 8 |
| re .623
>5. The AC/DC bus imbalance measurements exhibited some change. The DC
>measurement decreased 1 DN and reads 18.5 volts.
Something I've been meaning to ask for some time...
What's a DN?
|
| 560.625 | Definition of DN | CARROL::LEPAGE | Jinky rules!!! | Thu Apr 02 1992 16:33 | 15 |
| Re:.624
"DN" stands for "Data Number". As you probably already know, all
data transmitted from Galileo and most other spacecraft today is in a
digital form. Depending on the data format these numbers would range
from 0 to 64 or 0 to 255 or some other range of 2 to some power. This
number is a data number. For a voltage measurement like in this
example, the expected range of data, for example 0 to 50 volts, is
scaled so that it could be transmitted as an eight bit number. That
works out that each DN is the equivilent of about 2 volts. The data
range and number of bits per measurement are different on GAlileo, but
the idea is the same.
Drew
|
| 560.626 | HGA Update | VERGA::KLAES | All the Universe, or nothing! | Tue Apr 07 1992 20:08 | 114 |
| Article: 42474
From: higgins@fnalo.fnal.gov (Bill Higgins-- Beam Jockey)
Newsgroups: sci.space
Subject: HGA news from JPL (was Re: Gallileo Antenna)
Date: 1 Apr 92 01:08:34 GMT
Sender: news@fnnews.fnal.gov
Organization: Fermi National Accelerator Laboratory
In article <1992Mar31.201821.4403@sfu.ca>, palmer@sfu.ca (Leigh Palmer) writes:
> In article <1992Mar31.170621.17258@bradford.ac.uk>
> K.Haigh-Hutchinson@bradford.ac.uk (K.HAIGH-HUTCHINSON) writes:
>>How do the warming and cooling turns unstick the antenna?
>>
>>I know that metals contract and expand when cooled and warmed. I can see how
>>such a technique might work under gravity. The unstuck ribs, no longer
>>supporting each other, unfold due to the pull of gravity.
>>
>>My extremely limited physics tells me the ribs might well unstick but where
>>is the force to persuade them to move from their current position if they do?
[Higgins here; I haven't quoted Leigh Palmer yet.] The ribs are in a
partly unfolded "umbrella," so the other ribs, which have opened
correctly, are pulling on the three stuck ribs through the mesh
(corresponding to the fabric of the umbrella) which connects them all.
Here's a schematic ASCII diagaram (NOTHING is to scale here!!) of the
parts they're talking about:
/ / | Central |
/ / | tower |
/ / | |
/ / -------------- |
/ //////////) > Receptacle (has conical depression)
/ / Locator -------------- |
/ / pin | |
/ / (cylinder with rounded tip) |
Rib | |
The rounded, hemispherical end of the locator pin was supposed to pop
out of the shallow conical receptacle when the HGA opened. Best guess
is that the lubricant between them was worn away by vibration during
Galileo's extra round trip by truck across the USA. It was delivered
to the Cape in December 1986, then shipped back to JPL following the
*Challenger* disaster and Centaur cancellation. After JPL modified
the orbiter to withstand the heat of the VEEGA trajectory, it rode the
truck back to Florida one more time for launch in late 1989.
>>In other words, how can NASA detect the ribs are unstuck?
>>Is it some momentum from spinning the spacecraft?
>
> From a shift in the center of mass of the spacecraft, detected by monitoring
> the position of the spin axis, I believe.
This is correct. Another indication is that one of the good ribs
casts a shadow on the Sun gate sensor when the spacecraft is pointed
in a certain direction. From this shadow controllers can tell the
angle of the rib, which should change if the stuck ones pop loose and
the antenna opens like a flower.
By coincidence, *The Galileo Messenger* number 29, dated February
1992, just arrived yesterday, and it has a bit of good news. Recall
that HGA stands for "high gain antenna," Galileo's big dish. In the
"Up to Date" section, Matt Landano writes:
Analyzing the HGA
Continued analysis, modeling, and testing of the HGA support the
earlier finding that the HGA's most likely condition is that three
ribs are stuck in the stow position, no damage has occurred to the
motor drive mechanism, and no structural failure has occurred in
the drive train. Therefore, if the ribs can be released, full
capability to open the HGA is available.
Recent analyses of he cooling turn activities suggest that the
alignment pins may be slowly "walking" out of the receptacles.
The analyses further suggest that alternating maximum warming and
maximum cooling turns provides the best prospect of "freeing" the
ribs. Consequently, in addition to the December 1991 cooling
turn, three alternating warming-cooling turn activities have been
planned between January and the end of April 1992.
And in his "From the Project Manager" column, Bill O'Neil writes:
As yet, we have had no joy in our HGA rib-release campaign;
however, there is good reason to remain hopeful. A very
sophisticated, detailed computer model of all the pertinent forces
involved in the HGA was completed last fall. The model shows that
for reasonably expected misalignments and friction, the locating
pins do, indeed, "walk" out of their receptacles as the central
tower is cycled up and down by alternate warming and cooling.
Accordingly, we are now embarked on a very ambitious campaign of
thermal cycling the HGA with alternating warming and cooling
turns. Four cycles have been completed and eight more are planned
between March 1992 and March 1993. The displacements of the ribs
during the walking are much too small to detect in any spacecraft
telemetry measurements. However, once the pin-pair of a given rib
clears its receptacles, the rib will spring out, and this will be
clearly indicated by data from the Sun gate sensor. The first of
the three stuck ribs could release on any of the next turns. The
model indicates one or more additional thermal cycles will be
required between each of the subsequent rib releases. Every turn
has the exciting potential of a rib release-- stay tuned!
That's it from the horse's mouth.
O~~* /_) ' / / /_/ ' , , ' ,_ _ \|/
- ~ -~~~~~~~~~~~/_) / / / / / / (_) (_) / / / _\~~~~~~~~~~~zap!
/ \ (_) (_) / | \
| | Bill Higgins Fermi National Accelerator Laboratory
\ / Bitnet: HIGGINS@FNAL.BITNET
- - Internet: HIGGINS@FNAL.FNAL.GOV
~ SPAN/Hepnet: 43011::HIGGINS
|
| 560.627 | Updates - March 30 to April 7 | VERGA::KLAES | All the Universe, or nothing! | Wed Apr 08 1992 21:50 | 358 |
| Article: 636
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/30/92
Date: 31 Mar 92 07:53:53 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forward from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 30, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Over the weekend, no Spacecraft activity was scheduled. Tracking was
scheduled over DSS-63 (Madrid 70 meter antenna).
Today, March 30, 1992, no Spacecraft activity or tracking is scheduled.
Tomorrow, no Spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 642
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/31/92
Date: 1 Apr 92 01:31:03 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 31, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, no Spacecraft activity or tracking was scheduled.
Today, March 31, 1992, no Spacecraft activity or tracking is scheduled.
Tomorrow, the routine RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance along with routine science Memory Readouts (MROs) and a
Ultra-Stable Oscillator (USO) test are scheduled over DSS-14 (Goldstone 70
meter antenna) and DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 644
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/01/92
Date: 2 Apr 92 01:12:16 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 1, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, no Spacecraft activity or tracking was scheduled.
Today, April 1, 1992, the routine RPM (Retro Propulsion Module) 10-N
thruster "flushing" maintenance along with routine science Memory Readouts
(MROs) and a Ultra-Stable Oscillator (USO) test are scheduled over DSS-14
(Goldtone 70 meter antenna) and DSS-43 (Canberra 70 meter antenna).
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled
over DSS-63 (Madrid 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 660
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 04/01/92
Date: 3 Apr 92 01:56:33 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
April 1, 1992
The Galileo spacecraft is almost 432 million kilometers (268
million miles) from Earth, and about 327 million kilometers (203
million miles) from the Sun. This week it will reach its maximum
distance from Jupiter (1.1 billion kilometers or 692 million
miles), because of orbital geometry. Speed in orbit is 15.87
kilometers per second (35,500 mph).
The spacecraft is operating normally and transmitting coded
telemetry at 10 bits per second. Today it is scheduled to
transmit cruise-science data collected over the past few days and
is performing routine engineering checkouts and maintenance
operations. The Goldstone and Canberra Deep Space Stations are
tracking the spacecraft for these activities.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 662
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/02/92
Date: 3 Apr 92 02:51:22 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 2, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the routine RPM (Retro Propulsion) 10-N thruster "flushing"
maintenance along with routine EUV (Extreme Ultraviolet Spectrometer), DDS
(Dust Detector) and MAG (Magnetometer) science Memory Readouts (MROs) and a
Ultra-Stable Oscillator (USO) test were performed.
Today, April 2, 1992, no Spacecraft activity or tracking is scheduled.
Tomorrow, the uplink of the sequence memory load for Cooling Turn No. 6
is scheduled. Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna)
and DSS-63 (Madrid 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 671
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/03/92
Date: 4 Apr 92 03:00:37 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
March 27 - April 2, 1992
SPACECRAFT
1. On April 1, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect information for the gravitational
red shift experiment.
2. On April 1, cruise science Memory Readouts (MROs) were performed for the
Magnetometer (MAG), Dust Detector (DDS), and Extreme Ultraviolet Spectrometer
(EUV) instruments. Six out of 52 packets of EUVMRO data (11.5 percent) were
lost due to a station handover problem (DSS-14 and DSS-43 -
Goldstone/Canberra).
3. Solid-State Imaging (SSI) instrument routine Memory Readouts (MROs) were
performed on April 1. Because the SSI was turned off, as planned, the MRO
was all zeros, as expected.
4. On April 1, the periodic RPM (Retro Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed. The spacecraft went from the
dual-spin to the all-spin mode prior to the flushing activity and remained in
the all-spin mode after the flushing completed, which is the EE-5
(Earth-Earth 5) sequence background state. All 12 thrusters were flushed
during the activity. Spacecraft performance throughout the activity was
normal.
5. On April 1, a NO-OP command was sent to reset the command loss timer to
336 hours, its planned value for this mission phase.
6. The routine sun vector update was performed on April 2; the sun vector is
valid through May 30, 1992.
7. The AC/DC bus imbalance measurements exhibited some minor change. The DC
measurement increased 2 DN and reads 18.9 volts. The AC measurement remained
unchanged and reads 2.9 volts.
8. The Spacecraft status as of April 2, 1992, was as follows:
a) System Power Margin - 30 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/Star Scanner
d) Spacecraft Attitude is approximately 8 degrees off sun (lagging)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EPD, MAG, UVS, DDS, EUV, & HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 336 hours
Time To Initiation - 301 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Cooling Turn No. 6 mini-sequence was approved for transmission by the
Project on April 2, 1992. The Cooling Turn No. 6 activities are scheduled
from April 6 thru April 17. The bus pre-cool phase begins on April 6 and the
turn to cooling attitude begins on April 13, 1992.
GDS (Ground Data Systems):
1. A meeting was held to review the telemetry performance via the Low Gain
Antenna (LGA) during 1994 and 1995. Preliminary analysis indicates that
telemetry at 10 bps can be supported at maximum range using the DSN (Deep
Space Network) Block V receivers and suppressed carrier operations with the
Spacecraft. Since the Block V receivers are not expected to be available until
early 1995, telemetry performance gaps exist in 1994 with the DSN Block IV
receivers and the current Spacecraft telecommunication configuration. The
analysis presented indicated that performance gaps with the Block IV receivers
in 1994 could be eliminated by increasing the spacecraft telemetry modulation
index to 60 degrees and using a DSN receiver bandwidth of 3 HZ. A special mod
index test with the spacecraft is planned for next month.
2. Multimission Verification Tests (MVTs) with the 5th string DSN TPA
(Telmetry Processing Assembly) at Madrid and new software (OP-D) were cancelled
due to TPA hardware problems. The tests will be rescheduled at a later time.
3. Data flow checkouts to the NIMS (Near Infrared Mapping Spectrometer)
Processing Equipment (NPE) have begun in anticipation of Earth 2 activities.
Software and hardware changes have been made in the NPE since Earth 1. Data
was provided from the MCCC (Mission Control and Computing Center) Simulation
System via the wideband interface on March 26 and April 1. The interface
could not be successfully established during the first test but was
established on the second. A third data flow is scheduled for April 8 to
verify the second test results.
TRAJECTORY
As of noon Thursday, April 2, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 267,226,000 miles (2.88 AU)
Distance from Sun 203,245,000 miles (2.19 AU)
Heliocentric Speed 35,600 miles per hour
Distance from Jupiter 692,472,000 miles
Round Trip Light Time 47 minutes, 56 seconds
SPECIAL TOPICS
1. As of April 2, 1992, a total of 7648 real-time commands have been
transmitted to Galileo since Launch. Of these, 2897 have been pre-planned in
the sequence design and 4751 were not. In the past week, 1 real time command
was transmitted; 1 was pre-planned in the sequence design, none were unplanned.
In addition, 3567 mini-sequence commands have been transmitted since March
1991; (1316 were pre-planned and 2251 were not). In the past week, no
mini-sequence commands were transmitted. Major command activity this week
included resetting the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 696
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/06/92
Date: 7 Apr 92 01:51:46 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 6, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps (bits/second).
Over the weekend, no Spacecraft activity or tracking was scheduled.
Today, April 6, 1992, the pre-cool portion of Cooling Turn No. 6 is
scheduled to begin and will continue through April 13. Tracking is scheduled
over DSS-43 (Canberra 70 meter antenna).
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 702
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/07/92
Date: 8 Apr 92 00:40:35 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 7, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the pre-cool portion of Cooling Turn No. 6 began and will
continue through April 13.
Today, April 7, 1992, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-43 (Canberra 70 meter antenna).
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
|
| 560.628 | April plans for freeing the HGA | VERGA::KLAES | All the Universe, or nothing! | Fri Apr 10 1992 13:38 | 21 |
| From: DECWRL::"BAALKE@KELVIN.JPL.NASA.GOV" "Ron Baalke" 10-APR-1992
03:49:08.32
To: space-tech@cs.cmu.edu
Subj: Re: Galileo antenna rescue
The next cooling turn for Galileo is scheduled for April 13. The
spacecraft will be turned so that the High Gain Antenna is pointed
away from the sun for 50 hours, and then will turn back. This is part
of the continuing effort to alternately warm and cool the antenna to
work the stuck pins back and forth. There is a chance that this
particular cooling turn will free the antenna.
If this cooling turn doesn't work, then the deployment motors will be
turned on a second time for 2 seconds. This is scheduled for April 29.
The last time the motors were turned on was a year ago. This may
free the antenna. If it doesn't, it will still return data to better
characterize how stuck the antenna is.
Ron Baalke
baalke@kelvin.jpl.nasa.gov
|
| 560.629 | GALILEO Propulsion System stats | VERGA::KLAES | All the Universe, or nothing! | Fri Apr 10 1992 14:08 | 68 |
| From: DECWRL::"leech@cs.unc.edu" "Jon Leech" 9-APR-1992 20:32:36.37
To: space-tech@DAISY.LEARNING.CS.CMU.EDU
Subj: Re: Galileo antenna rescue
>Galileo will use a 400 newton rocket engine combined with a gravity assist of
>Io (1000 km closest approach) for the Jupiter orbit capture. There is no
>aerobraking involved. The rocket engine will fire for an hour; I don't have
>any numbers on the G forces the spacecraft will undergo.
I dug out my viewgraph copies from Ae107 (Case Studies in
Aeronautics: Galileo) at Caltech in 1987. The following is from the
talk titled "Galileo Propulsion Subsystem", presented by W. H. Tyler
(I dropped some decimal points for ease of typing). I imagine this isn't
the tour planned now, but the general pattern should be much the same.
Retropropulsion Module
Bi-propellant (MON-1; MMH)
Pressure regulated
Usable propellant - 935 kg
Dry mass (of retropropulsion module) - 180 kg
Propulsion Subsystem - General Characteristics
Configuration
Four equal volume propellant tanks
Two fuel (MMH)
Two oxidizer (NTO) 748 mm diameter
Two pressurant tanks
440 mm diameter
Two propellant isolation assemblies
Two pressurant control assemblies
Two cluster booms and cluster assemblies
One central body assembly
1219 mm diameter x 838 mm high
12 - 10 Newton thrust rocket engine assemblies
1 - 400 Newton thrust rocket engine assembly, centerline mounted
Two (redundant) 10 N feed systems
Boom, cluster, and central body thermal control blanket
10 N plume shields - one each boom
Propulsion Subsystem - Propellant Mass
Galileo Spacecraft Performance Calculation
Mission Profile Isp Dv Mi Mf Dm
(sec) (m/s) (kg) (kg) (kg)
Drop adapter - - 2654 2541 113
TCMS 287 75 2541 2474 66
Deep Space DV 287 82 2474 2402 71
Probe Separation - - 2402 2064 338
ODM 306 60 2064 2024 40
Drop AACS Prop 1 - - 2024 1986 38
JOI 306 613 1986 1618 367
OTM 287 7 1618 1614 4
PJR 306 366 1614 1429 185
Tour DV 285 154 1429 1392 76
Drop AACS Prop 2 - - 1352 1328 24
Orbiter Burnout Mass = 1271 kg Perijove Radius = 11.5 RJ
Propellant Margin = 57.8 kg # of Enc = 15.74
Tour Fuel Avail = 158.4 kg
So the insertion manuever should be ~0.24 m/s^2 (400N/1618 kg at
end of burn) or less than 2.5% g. This is in the ballpark of the
delta-V into the burn time Ron mentions - 613 m/s / 3600 s = 0.17 m/s^2.
Jon (leech@cs.unc.edu)
__@/
|
| 560.630 | Updates - April 7-9 | VERGA::KLAES | All the Universe, or nothing! | Fri Apr 10 1992 19:50 | 214 |
| Article: 719
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 04/07/92
Date: 9 Apr 92 06:56:09 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
April 7, 1992
The Galileo spacecraft is more than 422 million kilometers (262
million miles) from Earth, and 325.5 million kilometers from the Sun.
Speed in orbit is 16 kilometers per second (35,829 mph); round-trip
communication time is 47 minutes, 2 seconds.
The spacecraft is in a one-week pre-cooling period, and will
begin its sixth cooling turn next Monday, April 13. It is operating
normally, spinning, sun-pointed, and transmitting coded telemetry at
10 bits per second.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 720
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/08/92
Date: 9 Apr 92 06:58:01 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 8, 1992
The Galileo Spacecraft appears to be operating normally in the
all-spin mode and transmitting coded telemetry at 10bps. In
accordance with Cooling Turn No. 6 mini-sequence, we are operating in
a S-Band TWTA low power mode and have not been able to process
telemetry since Monday afternoon, as expected.
Yesterday, no Spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna).
Today, April 8, 1992, no Spacecraft activity is scheduled. The
pre-cool portion of Cooling Turn No. 6 is ongoing and will continue
until April 13. Tracking is scheduled over DSS-43.
Tomorrow, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 722
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/09/92
Date: 10 Apr 92 00:53:13 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 9, 1992
The Galileo Spacecraft appears to be operating normally in the
all-spin mode and transmitting coded telemetry at 10 bps
(bits/second). In accordance with Cooling Turn No. 6 mini-sequence,
we are operating in a S-Band TWTA (Traveling Wave Tube) low power mode
and have not been able to process telemetry consistently since Monday
afternoon, as expected.
Yesterday, no Spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra Deep Space Station, 70 meter antenna).
Today, April 9, 1992, no Spacecraft activity is scheduled. The
pre-cool portion of Cooling Turn No. 6 is ongoing and will continue
until April 13. Tracking is scheduled over DSS-43.
Tomorrow, under stored sequence control, the S-Band TWTA will be
commanded to the high power mode to process telemetry for
approximately 2 1/2 hours. Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 724
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 04/09/92
Date: 10 Apr 92 06:57:52 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
April 3 - 9, 1992
SPACECRAFT
1. On April 3, the Cooling Turn No. 6 sequence memory load was sent to the
spacecraft. Additionally, Memory Readout (MRO) commands were sent to verify
the sequence was loaded correctly. The sequence was loaded on the spacecraft
without incident (see Special Topic No. 2).
2. On April 3, Delayed Action Commands (DACs) were uplinked to turn off the
NIMS (Near Infrared Mapping Spectrometer) Radiometric Calibration Target
(RCT) heater (24 watt) on April 10 and back on April 13 during the Cooling
Turn No. 6 sequence. These actions are necessary to maintain required system
power margin.
3. On April 3, a delta Differenced One-Way Range (DOR) was performed over
DSS-14 (Goldtone 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Initial results indicate that the delta DOR was successfully performed.
4. On April 6, a NO-OP command was sent to reset the command loss timer to
336 hours, its planned value for this mission phase.
5. On April 6, the Cooling Turn No. 6 sequence memory load went active. The
pre-cool portion of the sequence started on April 6 and will be completed on
April 13. During this pre-cool phase the S-band TWTA (Traveling Wave Tube) is
set to low power mode and consequently, as expected, telemetry data has not
been consistently processed since April 7 at approximately 0014 UTC.
6. The AC/DC bus imbalance measurements remained unchanged. The DC
measurement reads 18.9 volts. The AC measurement reads 2.9 volts.
7. The Spacecraft status as of 1700 PDT April 9, 1992, could not be determined
by real-time telemetry because the spacecraft is in the pre-cool portion of
Cooling Turn No. 6 with the S-band TWTA in the low power mode. The following
information is taken from previous spacecraft performance and predicts.
a) System Power Margin - 26 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/Star Scanner
d) Spacecraft Attitude is approximately 10 degrees off sun (lagging)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EPD, UVS, HIC & SSI are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 336 hours
Time To Initiation - 259 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The High Gain Antenna (HGA) motor turn-on mini-sequence was approved for
generation by the Project on April 9, 1992. The HGA motor is scheduled to be
turned on April 29 for a duration of two seconds.
TRAJECTORY
As of noon Thursday, April 9, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 260,527,000 miles (2.80 AU)
Distance from Sun 201,855,000 miles (2.17 AU)
Heliocentric Speed 36,000 miles per hour
Distance from Jupiter 692,417,000 miles
Round Trip Light Time 46 minutes, 44 seconds
SPECIAL TOPICS
1. As of April 9, 1992, a total of 7689 real-time commands have been
transmitted to Galileo since Launch. Of these, 2930 have been pre-planned in
the sequence design and 4759 were not. In the past week, 41 real time command
was transmitted; 33 were pre-planned in the sequence design, 8 were unplanned.
In addition, 3999 mini-sequence commands have been transmitted since March
1991; (1748 were pre-planned and 2251 were not). In the past week, 432
mini-sequence commands were transmitted. Major command activities this week
included commands to: uplink and verify the Cooling Turn No. 6 sequence memory
load, turn the NIMS Radiometric Calibration Target (RCT) heater off and on,
and reset the command loss timer.
2. The Cooling Turn No. 6 activities are scheduled from April 6 to April 17.
The spacecraft bus cool down period started on April 6 and will continue until
April 13. The cooling turn will be performed on April 13 and the spacecraft
will remain at the cooling attitude for approximately 50 hours. The spacecraft
return from the cooling attitude is scheduled for April 16. The sun gate and
wobble ID data collection is scheduled during the April 16-17 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
|
| 560.631 | Updates - April 10-16 | VERGA::KLAES | All the Universe, or nothing! | Fri Apr 17 1992 19:18 | 234 |
| Article: 728
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/10/92
Date: 11 Apr 92 01:10:56 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 10, 1992
The Galileo Spacecraft appears to be operating normally in the all-spin
mode and transmitting coded telemetry at 10 bps. In accordance with Cooling
Turn No. 6 mini-sequence, we are operating in a S-Band TWTA low power mode and
have not been able to process telemetry consistently since Monday afternoon,
as expected.
Yesterday, no Spacecraft activity was scheduled. Tracking was scheduled
over DSS-43 (Canberra 70 meter antenna).
Today, April 10, 1992, under stored sequence control, the S-Band TWTA
will be commanded to the high power mode to process telemetry for approximately
2 1/2 hours.
Over the weekend, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-43 and DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 786
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 04/13/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 14 Apr 1992 05:27:42 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 13, 1992
The Galileo Spacecraft appears to be operating normally in the all-spin
mode and transmitting coded telemetry at 10 bps. On Friday, the S-band TWTA
was commanded to the high power mode and telemetry data was processed for
approximately 2-1/4 hours indicating the Spacecraft is operating normally.
Over the weekend, no Spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna) and DSS-14 (Goldstone 70
meter antenna).
Today, April 13, 1992, Cooling Turn No. 6 to a 165 degree off-sun attitude
is scheduled to begin at approximately 1423 PDT. Loss of downlink carrier is
expected to occur at approximately 1522 PDT during the maneuver to the cooling
attitude. The Spacecraft will remain at the cooling attitude for approximately
50 hours. Tracking is scheduled over DSS-43.
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled over
DSS-63 (Madrid 70 meter antenna) and DSS-43. Coverage is required as a
precautionary measure to assure the earliest possible warning of a Spacecraft
problem since telemetry data at the cooling attitude is not expected.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 790
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/14/92
Date: 15 Apr 92 05:36:33 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 14, 1992
The Galileo Spacecraft is at the cooling attitude and appears to be
operating normally in the all-spin mode and transmitting coded telemetry at
10 bps (bits/second).
Yesterday, prior to the start of Cooling Turn No. 6, the S-band TWTA
(Traveling Wave Tube) was commanded to the high power mode and telemetry data
was processed for approximately 3 hours indicating the Spacecraft is operating
normally. Cooling Turn No. 6 was then completed as scheduled to a 165 degree
off-sun attitude. Loss of downlink carrier occurred close to the predicted
time at approximately 1506 PDT during the maneuver to the cooling attitude.
Tracking was scheduled over DSS-43 (Canberra 70 meter antenna).
Today, April 14, 1992, no Spacecraft activity is scheduled. Partial
tracking is scheduled over DSS-63 (Madrid 70 meter antenna) and DSS-43.
Coverage is required to provide an indication of a downlink signal in case of
a Spacecraft safing action; due to geometric conditions, there is no
downlink signal while at the cooling attitude.
Tomorrow, the Spacecraft, under stored sequence control, will return from
the cooling attitude to a 5 degree off-sun attitude; the sun acquisition will
complete at approximately 2041 PDT. Tracking is scheduled over DSS-43 and
DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | People will believe
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | anything if you whisper it.
|_____|/ |_|/ |_____|/ |
Article: 798
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 04/15/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 16 Apr 1992 01:46:17 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 15, 1992
The Galileo Spacecraft is at the cooling attitude and appears to be
operating normally in the all-spin mode and transmitting coded telemetry at
10 bps.
Yesterday, no Spacecraft activity was scheduled. Short tracking passes
were scheduled over DSS-63 (Madrid 70 meter antenna) and DSS-43 (Canberra
70 meter antenna). Coverage is required to provide an indication of a
downlink signal in case of a Spacecraft safing action; due to geometric
conditions, there is no downlink signal while at the cooling attitude.
Today, April 15, 1992, the Spacecraft, under stored sequence control, will
return from the cooling attitude to a 5 degree off-sun attitude; the sun
acquisition will complete at approximately 2041 PDT. Tracking is scheduled
over DSS-43 and DSS-63.
Tomorrow, real-time commands are scheduled to checkout the Star Scanner
(SS) and reacquire celestial reference along with collecting wobble ID data.
Tracking is scheduled over DSS-63, DSS-14 (Goldstone 70 meter antenna), and
DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | sympton.
|_____|/ |_|/ |_____|/ |
Article: 809
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/16/92
Date: 17 Apr 92 05:56:58 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 16, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the Spacecraft, under stored sequence control, returned from
the cooling attitude to a 5 degree off-sun attitude; the sun acquisition was
completed at approximately 2025 PDT. Sun gate data indicated no change in
antenna rib configuration.
Today, April 16, 1992, real-time commands are scheduled to checkout the
Star Scanner (SS) and reacquire celestial reference along with collecting
wobble ID data. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna),
DSS-14 (Goldstone 70 meter antenna), and DSS-43 (Canberra 70 meter antenna).
Tomorrow, real-time commands are scheduled to update the system fault
protection in preparation for the HGA (High Gain Antenna) motor turn-on planned
for April 29. Tracking is scheduled over DSS-14 and DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | sympton.
|_____|/ |_|/ |_____|/ |
Article: 810
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 04/16/92
Date: 17 Apr 92 05:58:49 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
April 16, 1992
The Galileo spacecraft is almost 408 million kilometers (more
than 253 million miles) from Earth, and 322 million kilometers or 201
million miles from the Sun. Its speed in orbit is 16.26 kilometers per
second, or 36,369 mph. Round-trip communication time is 45 minutes,
16 seconds.
The spacecraft is operating normally, transmitting coded
telemetry at 10 bits per second. Wednesday night it turned back to
the Sun-pointed cruise-mode attitude at the conclusion of the sixth
cooling turn, part of the program to free Galileo's stuck high-gain
antenna and permit it to be fully deployed. Post-turn data from the
spacecraft sun-gate sensor indicated no change in the antenna configuration.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | sympton.
|_____|/ |_|/ |_____|/ |
|
| 560.632 | More Gaspra images in May | VERGA::KLAES | All the Universe, or nothing! | Wed Apr 22 1992 21:02 | 25 |
| Article: 43407
Newsgroups: sci.space
From: stooke@vaxr.sscl.uwo.ca
Subject: RE: new Gaspra image in May
Organization: Social Science Computing Laboratory
Date: Wed, 22 Apr 1992 15:28:05 GMT
Sender: news@julian.uwo.ca (USENET News System)
Regarding the Galileo Gaspra images:
Yes indeed, some Gaspra data will be transmitted in May. The project
has a bit of DSN time. It is thought that the image is on Frame 37 of
the 50 frame mosaic taken just before closest approach. First, 12
lines will be transmitted from the expected position of the asteroid
(which will fill about 300 lines of an 800 line image), to confirm its
presence. Then on May 19 100 lines will be sent down, and another 56
the next day, and so on until they have that one high resolution
frame. The resolution will be about 50 m, compared with 160 m in the
images seen already. The remaining images taken earlier in the
rotation, showing the back side of the body at very low resolution,
will have to wait until November. There may be some NIMS spectral
data returned in May, but I have no specific info on that.
Phil Stooke
|
| 560.633 | Updates - April 20-24 | VERGA::KLAES | All the Universe, or nothing! | Sat Apr 25 1992 20:32 | 392 |
| Article: 830
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 04/20/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 21 Apr 1992 02:37:18 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 20, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Over the weekend, no Spacecraft activity was scheduled. Tracking was
scheduled on Sunday over DSS-43 (Canberra 70 meter antenna).
Today, April 20, 1992, an Energetic Particle Detector (EPD) motor
maintenance exercise is scheduled. Tracking is scheduled over DSS-43.
Tomorrow, the routine RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance activity along with a delta Differenced One-Way Range
(DOR) is scheduled over DSS-14 (Goldtone 70 meter antenna) and DSS-63 (Madrid
70 meter antenna). Additionally, real-time commands are scheduled to be sent
to verify the successful completion of the EPD motor maintenance exercise.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | sympton.
|_____|/ |_|/ |_____|/ |
Article: 825
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Asteroid Lectures at Griffith Observatory
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Mon, 20 Apr 1992 08:26:16 GMT
The Griffith Observatory in Los Angeles, California, in cooperation with
The Planetary Society, are sponsoring a series of evening lectures by JPL
experts on asteroids. The lectures are held on Mondays at 7:30 PM at the
following location:
Planetarium Theater
Griffith Observatory
2800 East Observatory Road
Los Angeles, CA
Phone: (213) 664-1191
Admission is $3.50 and tickets are sold at the Griffith Observatory one
half hour before the lecture. The following lectures are scheduled:
April 20 - Investigating Asteriods by Radar - Dr. Steven Ostro
Bouncing radar beams off asteroids and studying the echoes
give us surpising and useful information about asteroids'
sizes, shapes, surface structures and orbits. Improvments
will soon let us see near-Earth asteroids with the clarity
of Galileo's images of minor planet Gasrpa. This lecture
shows recent results and describes new radar experiments
being planned.
April 27 - Asteroids and the Dinosaur Extinctions - Dr. Paul Weissman
This talk explores the theory that the impact of a
six-mile-diameter asteroid or comet 65 million years ago was
responsible for the extinction of the dinosaurs and many other
species. The event could be repeated -- fossil records show
that major impacts happended frequently in the past and will
continue into the future.
June 1 - Galileo Encounters Gaspra - Dr. Torrence Johnson
The chief scientist for Galileo reviews the exciting results
of our first closeup look at a minor planet -- Gaspra --
visited by Galileo last autumn while enroute to Jupiter.
Dr. Johnson discusses how we observe asteroids by spacecraft
and what we learned about Gaspra. Highlights include the
latest pictures of Gaspra.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | sympton.
|_____|/ |_|/ |_____|/ |
Article: 837
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/21/92
Date: 23 Apr 92 03:00:58 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 21, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps (bits/second).
Yesterday, an Energetic Particle Detector (EPD) motor maintenance exercise
was performed. Tracking was scheduled over DSS-43 (Canberra 70 meter antenna).
Today, April 21, 1992, the routine RPM (Retro Propulsion Module) 10-Newton
thruster "flushing" maintenance activity along with a delta Differenced One-Way
Range (DOR) is scheduled over DSS-14 (Goldstone 70 meter antenna) and DSS-63
(Madrid 70 meter antenna). Additionally, real-time commands are scheduled to
be sent to verify the successful completion of the EPD motor maintenance
exercise.
Tomorrow, routine science Memory Readouts (MROs) along with a Ultra-Stable
Oscillator (USO) test are scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 838
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/22/92
Date: 23 Apr 92 03:02:49 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 22, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, the routine RPM (Retro Propulsion Module) 10-N thruster
flushing maintenance activity along with a delta Differenced One-Way Range
(DOR) was performed over DSS-14 (Goldstone 70 meter antenna) and DSS-63
(Madrid 70 meter antenna). Additionally, real-time commands were sent to
verify the successful completion of the EPD (Energetic Particles Detector)
motor maintenance exercise.
Today, April 22, 1992, routine science Memory Readouts (MROs) along with
a Ultra-Stable Oscillator (USO) test are scheduled over DSS-43 (Canberra 70
meter antenna).
Tomorrow, real-time commands are scheduled to perform routine science
Memory Readouts (MROs). Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 842
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/23/92
Date: 24 Apr 92 05:25:09 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 23, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10bps.
Yesterday, routine science Memory Readouts (MROs) along with a
Ultra-Stable Oscillator (USO) test were performed over DSS-43 (Canberra 70
meter antenna).
Today, April 23, 1992, real-time commands are scheduled to perform
routine science Memory Readouts (MROs) along with uplinking the HGA (High
Gain Antenna) diagnostic motor turn-on mini-sequence. The motor is scheduled
to be turned on for 2 seconds on April 29, 1992. Tracking is scheduled over
DSS-43.
Tomorrow, no Spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 845
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 04/23/92
Date: 24 Apr 92 08:28:47 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
April 17 - 23, 1992
SPACECRAFT
1. On April 17, as part of the Cooling Turn No. 6, commands were sent to open
the Star Scanner (SS) shutter and to reacquire celestial reference.
Additionally, the AACS (Attitude and Articulation Control Subsystem) gyro-based
wobble data was collected with the spacecraft in the dual-spin mode. Analysis
of the data indicates no change in wobble as a result of the cooling turn
corroborating the sun gate obscuration data. After the turn, Probe shelf
temperatures (T2) reached 27.7 degrees C which was approximately 1.4 degrees
above predicts but well below the maximum allowable temperature of 35
degrees C (see Special Topic 2).
2. On April 17, commands were sent to update the system Fault Protection (FP)
such that if spacecraft safing is invoked, the spacecraft will turn to the
earth as opposed to the sun.
3. On April 17, commands were sent to update the system Fault Protection (FP)
such that if the HGA (High Gain Antenna) diagnostic motor turn-on sequence is
terminated, FP will automatically turn off the HGA motors.
4. On April 20, Solid State Imaging (SSI) instrument routine Memory Readouts
(MROs) were performed. The SSI MROs were expected to be all zeros because the
SSI was turned off, as planned. The MRO data was not received on the ground
due to planned DSN (Deep Space Network) maintenance at DSS-43 (Canberra 70
meter antenna).
5. On April 20, routine Extreme Ultraviolet Spectrometer (EUV) Memory Readouts
(MROs) were performed. The MRO data was not received on the ground due to
planned DSN maintenance at DSS-43. Real-time MRO commands were sent on
April 23 to retrieve this EUV cruise science data.
6. On April 20, the Energetic Particle Detector (EPD) motor maintenance
exercise was performed which stepped the motor through its eight operating
positions and then returned it to the nominal position (No. 4). The MRO data
was not received on the ground due to planned DSN maintenance at DSS-43.
Real-time MRO commands were sent on April 21 to retrieve the EPD engineering
data and verify the successful completion of the motor maintenance exercise.
7. On April 21, a delta Differenced One-Way Range (DOR) was performed over
DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Initial results indicate that the delta DOR was successfully performed.
8. On April 21, the periodic RPM (Retro Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed. The spacecraft went from the
dual-spin to the all-spin mode prior to the flushing activity and remained in
the all-spin mode after the flushing completed, which is the EE-5
(Earth-Earth 5) sequence background state. All 12 thrusters were flushed
during the activity.
9. On April 22, cruise science Memory Readouts were performed for the
Magnetometer (MAG) instrument.
10. On April 22, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect information for the gravitational
red shift experiment.
11. On April 22, cruise science Memory Readouts (MROs) were performed for the
Dust Detector (DDS). The MRO data was not received on the ground due to
planned DSN maintenance at DSS-43. Real-time MROs were sent on April 23 to
retrieve the DDS cruise science data.
12. On April 23, the HGA diagnostic motor turn-on sequence memory load was sent
to the spacecraft. The sequence covers spacecraft activities from April 27,
1992 to May 4, 1992 (see Special Topic No. 3).
13. The AC/DC bus imbalance measurements remained relatively unchanged. The
DC measurement reads 18.3 volts. The AC measurement reads 2.9 volts.
14. The Spacecraft status as of 1700 PDT April 23, 1992, is as follows:
a) System Power Margin - 30 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89rpm/Star Scanner
d) Spacecraft Attitude is approximately 5 degrees off sun (leading)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 336 hours
Time To Initiation - 333 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The High Gain Antenna (HGA) diagnostic motor turn-on mini-sequence was
approved for transmission by the Project on April 22, 1992. The HGA motor is
scheduled to be turned on April 29 for a duration of two seconds.
GDS (Ground Data Systems):
1. Galileo participated in two Multimission Verification Tests (MVTs) for the
new DSN telemetry software (TPA OP-D) on April 10 and April 17. During both
of these tests excessive data loss was seen at higher bit rates. The DSN has
determined that an anomaly exists in OP-D software that will not allow it to be
used in the Galileo configuration on the 5th TPA String. A schedule for
re-delivery and re-testing is TBD.
TRAJECTORY
As of noon Thursday, April 23, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 245,780,000 miles (2.65 AU)
Distance from Sun 198,730,000 miles (2.14 AU)
Heliocentric Speed 36,800 miles per hour
Distance from Jupiter 691,845,000 miles
Round Trip Light Time 44 minutes, 6 seconds
SPECIAL TOPICS
1. As of April 23, 1992, a total of 7859 real-time commands have been
transmitted to Galileo since Launch. Of these, 3004 were pre-planned in the
sequence design and 4855 were not. In the past week, 127 real time commands
were transmitted; 31 were pre-planned in the sequence design and 96 were not.
In addition, 4204 mini-sequence commands have been transmitted since March
1991; (1953 were pre-planned and 2251 were not). In the past week, 205
mini-sequence commands were transmitted. Major command activities this week
included commands to: open the Star Scanner (SS) shutter and to reacquire
celestial reference, update system Fault Protection, perform Memory Readouts
(MROs) of the EPD, EUV and DDS instruments, and uplink the HGA diagnostic
mini-sequence.
2. The Cooling Turn No. 6 activities were scheduled from April 6 to April 17.
The spacecraft bus cool down period started on April 6 and completed on
April 13. The cooling turn was performed on April 13 and the spacecraft
remained at the cooling attitude for approximately 50 hours. The spacecraft
return from the cooling attitude occurred on April 16. The sun gate and wobble
ID data collection was performed during the April 16-17 time period.
3. The HGA diagnostic motor turn-on sequence memory load was sent to the
spacecraft on April 23, 1992. This sequence covers spacecraft activities from
April 27, 1992 to May 4, 1992. The motor turn-on for approximately 2 seconds
is scheduled on April 29, 1992 at 3:22 PDT. The Star Scanner (SS) checkout,
return to celestial reference and the wobble ID test are scheduled for
May 1, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 847
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 04/24/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 25 Apr 1992 05:51:18 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 24, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 10 bps (bits/second).
Yesterday, the HGA (High Gain Antenna) motor turn-on mini sequence memory
load was sent; the motor is scheduled to be turned on for approximately 2
seconds on April 29, 1992. Additionally, real-time commands were sent to
perform routine science Memory Readouts (MROs). Tracking was scheduled over
DSS-43 (Canberra 70 meter antenna).
Today, April 24, 1992, no Spacecraft activity or tracking is scheduled.
Over the weekend, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
|
| 560.634 | Power Consumption | OPG::CHRIS | Capacity! What Capacity ? | Mon Apr 27 1992 08:49 | 2 |
| With all this spacecraft shutdown to reduce heat, will this have anye
effect on power consumption ?
|
| 560.635 | | PRAGMA::GRIFFIN | Dave Griffin | Mon Apr 27 1992 12:29 | 19 |
| If you are asking, in effect, "will the batteries last longer?", I think the
answer is no.
Galileo is powered by RTGs, which derive their power from heat given off by
the decay of an isotope of plutonium (there are replies buried in this note
about RTGs in some detail).
The thermal output of the RTG's is "fixed" by nature: it will decrease at a
particular rate, but there is no throttling allowed. The power systems convert
the heat to the electricity required by the spacecraft (up to some maximum),
and any excess energy is sent into space as heat via a shunt.
The RTGs are located on a boom somewhat far away from the main bus of the
spacecraft, so (I assume) the raditional effects of this "excess" heat caused
by instrument power downs is a lot less than if the heat was generated on the
bus.
- dave
|
| 560.636 | No better batteries, but uses up "gas" | DECWIN::FISHER | I *hate* questionnaires--Worf | Mon Apr 27 1992 15:34 | 9 |
| Of course all this mucking around undoubtedly reduces the amount of manuvering
fuel available. I'd bet that if they get the antenna unstuck they will skip
the next asteroid encounter because of low fuel.
(If they don't get it open, they may decide that they need a chance to get some
additional good out of a spacecraft which will be marginally useful when it gets
to Jupiter anyway).
Burns
|
| 560.637 | | HELIX::MAIEWSKI | | Mon Apr 27 1992 20:57 | 28 |
| The space craft will be much more than marginally useful when it gets to
Jupiter, even if they don't open the antenna. They will get all the data from
the probe, which will be the 1st ever to enter a gas giant and they will also
get most of the scientific data, which can be transmitted at low baud rates.
The only thing compromised are the pretty pictures and with improved data
compression and improved ground receivers, those may turn out ok as well.
As for PR, I think they can win there. Everyone is expecting the thing to be
a complete bust, so even if they send a few pictures using other data to figure
out which ones will be interesting, people will be pleasantly surprised.
Another technique, perhaps opposite of data compression, would be to send
every nth pixel and interpolate to fill in the blanks. That might show which
pictures had interesting features and those pictures could be selected for
either full broadcast or for broadcast of interesting parts.
One final thought. Often pictures overlap. With some creative programming
it should be possible to transmit only that part of a picture that showed
something not seen in a previous shot. Then there is always the possibility
of having some primitive type of pattern recognition to allow the on board
computers to make intelligent guesses of what would be interesting to
transmit.
Anyway, I hope they open the antenna, but I'm still psyched. I think they
are going to discover some neat stuff with or without the big antenna.
George
|
| 560.638 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Tue Apr 28 1992 15:11 | 13 |
| Well, George, I hear what you are saying and don't disagree with all the
possibilities you sketch out. However, 10 bits per second is a HECKuva lot
less then the HGA bit rate (which I don't remember...Magellen is in the hundreds
of Kbaud, though it is a lot closer than Jupiter on average). I call that kind
of degradation a change from "nominal" to "marginal".
My thought was that they might consider an extra year's worth (or whatever) of
Jupiter data at 10 baud less valuable than getting any information at all from
Ida. Whereas at upteen-K baud, they might consider significant extra time at
Jupiter more worthwhile than a second asteroid. Pure speculation, of course.
I think I neglected to say this in .-2.
Burns
|
| 560.639 | | HELIX::MAIEWSKI | | Tue Apr 28 1992 15:55 | 18 |
| Don't forget that they expect to improve the performance of the low gain
antenna by a factor of 10 to 100 by improving the ground based receivers which
will give them 100 to 1000 baud instead of 10. That, along with things like
data compression, interpolation, and pattern recognition could increase the
useful data rate many fold. They could even transmit at a speed that resulted
in a 10% to 20% error rate and use interpolation to make corrections which
might result in a real error rate that was very low.
Remember, they wrote the original software with the assumption that the data
transfer rate would not be a bottle neck. There are many old standard
techniques that can be used and new ones that can be improvised now that they
know that the data transfer rate is a factor.
I'll bet in the end they will lose very little, even if they don't open the
antenna. The major factor on their side is that they have a very long lead time
to update the software.
George
|
| 560.640 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Tue Apr 28 1992 16:37 | 25 |
| George,
I disagree 100% with your contention that the data transfer rate was
not the original bottle neck.
Sure they were planning on hundreds (thousands?) of pictures, but
Galelio is to orbit Jupiter with a useful life of, what? five years?
If I remember right data transmission originally amounted to something
under 10 pictures per day average transmission.
Sounds to me like data transfer was a recognized bottle neck FROM THE
BEGINNING.
Sounds to me like I would LOVE to use all your fancy techniques to
squeze more data out of a 10 bit stream on a hunhdreds of kilobits
stream. I think THAT would be really nice, no STUNNING.
You can say they will get very useful data and nice pictures even with
the hga down. You may even be right. Yet if the hga is unable to be
oppened, I will still be left with the thought: What might have been
.....
Tony
|
| 560.641 | | HELIX::MAIEWSKI | | Tue Apr 28 1992 19:29 | 28 |
| But it wasn't that much of a bottle neck. For example consider the following:
One of the big advantages of hanging around for 5 years is that they will get
to fly past some moons several times. Now under the old scheme they probably
would have taken pictures on each pass, and sent them all back to be analyzed.
At 10 pictures a day they could probably record a bunch of pictures and send
back 50 or more by the time they reached the next thing to look at so sending
back many pictures each pass would be no big deal.
However with limited data transfer, on the 2nd pass over the same area they
could keep old copies of pictures inside the local memory. Then they could
take a new picture, calculate the differences due to lighting, and compare
for differences. If something changed (not due to light) that would be worth
sending back (i.e. volcanic activity, clouds, what ever). If the picture was
the same or close to being the same then it would be passed over. Also, only
the part of the picture that changed would need to be transferred.
The point is that with the HGA, the data transfer rate was such that those
things didn't need to be done. At least I haven't read of anything like that
being attempted. With a restriction there are all sorts of tricks to save
on bits. Sure you lose some stuff, but with a little creativity they should
be able to get about the same amount of science.
And no matter how you cut it, if the atmosphere probe works the results
returned will be worth the cost of the mission even if they don't get back a
single picture.
George
|
| 560.642 | | FASDER::ASCOLARO | Not Short, Vertically Challenged | Tue Apr 28 1992 20:28 | 21 |
| George,
I think you are assuming a MUCH larger local memory than exists.
From my memory, which is sometimes quite unreliable, the local memory
on Galelio is tiny. So you can't do all the fancy things you are
talking about.
And I also have to disagree VIOLENTLY with your assertion that "if the
atmosphere probe works the results returned will be worth the cost of
the mission even if they don't get back a single picture."
I'm not even sure the complete mission woudl have been worth the cost,
which is now over one billion dollars. Certainly without any pictures,
Galelio is a failure of the HIGHEST magnitude, even if the atmospheric
probe is superbly successful. It is a pretty dumb probe, and it only
lasts about 100 minutes in atmosphere. So your saying that 100 minutes
of data is worth $1 Billion? $10 million a minute? I don't believe
you meant that George.
Tony
|
| 560.643 | | HELIX::MAIEWSKI | | Tue Apr 28 1992 20:57 | 17 |
| A probe going somewhere we have never gone before has got to be worth as much
as pictures of something that we have already seen before. Especially when you
consider that it's not a matter of not seeing any pictures but just seeing
fewer pictures. Right now we can only guess the chemical composition, weather,
electrical forces, and other aspects of the atmosphere of a gas giant.
When you consider that gas giants are an important stepping stone between
smaller planets and stars it seems apparent that this probe could tell us not
only what Jupiter is like but may give us an important interpolation point to
predict what many bodies are like who's mass is between a gas giant and a small
star. This probe is up there with Voyager 1, the gamma ray observatory and the
1st space based infrared telescope in terms of being something to go somewhere
and to see something we have never seen before.
To me, it's worth it.
George
|
| 560.644 | Probe @#$%^ | OPG::CHRIS | Capacity! What Capacity ? | Wed Apr 29 1992 08:44 | 3 |
| We are also assuming that the probe will work. With all the problems
of the probe due to its movements back and forth to the space center
nothing would surprise me..
|
| 560.645 | Let's hold our breaths anyway... | DECWIN::FISHER | I *hate* questionnaires--Worf | Wed Apr 29 1992 17:32 | 7 |
|
Well, regardless of how useful we think Galileo will be w/o the HGA, let's
hold our breath for the motor turn-on scheduled about 4 hours from now
(3:22 PDT). Actually, they did not say if it was AM or PM, but it was not
in military format (i.e. 0322) either.
Burns
|
| 560.646 | Motor On = Open | OPG::CHRIS | Capacity! What Capacity ? | Fri May 01 1992 08:55 | 1 |
| anyone know what happend !!!!????
|
| 560.647 | I'm afraid not... | PRAGMA::GRIFFIN | Dave Griffin | Fri May 01 1992 14:00 | 5 |
| The current monitors on the power system indicated the motor started to
load up about 100 milliseconds after activation. Sun gate data
indicates that no rib release took place.
- dave
|
| 560.648 | Galileo Update - 04/30/92 | CXDOCS::J_BUTLER | E poi, si muove... | Fri May 01 1992 16:59 | 129 |
| Article 32540 of sci.space:
Path: shodha.enet.dec.com!pa.dec.com!decwrl!sun-barr!ames!elroy.jpl.nasa.gov!kelvin.jpl.nasa.gov!baalke
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: Galileo Update - 04/30/92
Keywords: Galileo, JPL
Message-ID: <1992Apr30.233511.16272@elroy.jpl.nasa.gov>
Date: 1 May 92 07:34:43 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Reply-To: baalke@kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Lines: 111
Xref: shodha.enet.dec.com sci.space:32540 sci.astro:17894
News-Software: VAX/VMS VNEWS 1.3-4
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
April 24 - 30, 1992
SPACECRAFT
1. On April 27, as part of the HGA (High Gain Antenna) diagnostic motor
turn-on sequence activity, a science turn (SITURN) was commanded which oriented
the spacecraft to a 16-degree off earth pointed attitude (earth lagging) in
order to improve telecommunications (telecom) performance. Real-time commands
were then sent to change the telemetry rate from 10 bps to 40 bps coded
telemetry in support of the HGA diagnostic motor turn on April 29, 1992 (see
Special Topic 2).
2. On April 27, Delayed Action Commands (DACs) were sent to turn the
Radiometric Calibration Target (RCT) NIMS (Near Infrared Mapping Spectrometer)
heater on earlier than the planned turn-on in the HGA diagnostic motor turn-on
sequence. This will reduce the depth of the thermal cycle experienced by the
RCT-NIMS. The result will be that the heater will be off for 8 minutes instead
of 74 minutes; reducing the thermal cycle to 21 degrees C on May 1, 1992 (see
Special Topic 2).
3. On April 29, as part of the HGA diagnostic motor turn-on sequence activity,
the HGA motor was turned on at 22:43 UTC for approximately 2 seconds. The
system shunt current telemetry was collected at the highest possible sample
rate and stored on the tape recorder (DMS) for playback. The data was
subsequently played back between 23:00 UTC and 02:34 UTC. Initial sun gate
data indicates that the sun gate is still obscured, indicating no ribs
released. Subsequent "quick look" current analysis indicates that the motor
stalled within approximately 100 milliseconds of turn on. Detailed analysis
is in process (see Special Topic No. 2).
4. The AC/DC bus imbalance measurements exhibited some change. THe DC
measurement decreased 4 DN and reads 17.8 volts. The AC measurement remained
unchanged and reads 2.9 volts.
5. The Spacecraft status as of 1700 PDT April 30, 1992, is as follows:
a) System Power Margin - 30 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 5 degrees off
sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are
powered on
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 336 hours
Time To Initiation - 264 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-6 (Earth-Earth 6) Preliminary Sequence and command generation was
approved by the Project on April 29,1992. This sequence controls spacecraft
activities from May 11, 1992 to August 10, 1992.
TRAJECTORY
As of noon Thursday, April 30, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 237,800,000 miles (2.56 AU)
Distance from Sun 196,990,000 miles (2.12 AU)
Heliocentric Speed 36,800 miles per hour
Distance from Jupiter 691,320,000 miles
Round Trip Light Time 42 minutes, 42 seconds
SPECIAL TOPICS
1. As of April 30, 1992, a total of 7864 real-time commands have been
transmitted to Galileo since Launch. Of these, 3007 were pre-planned in the
sequence design and 4857 were not. In the past week, 5 real time commands were
transmitted; 3 were pre-planned in the sequence design and 2 were not. In
addition, 4204 mini-sequence commands have been transmitted since March 1991;
(1953 were pre-planned and 2251 were not). In the past week, no mini-sequence
commands were transmitted. Major command activities this week included commands
to: change the telemetry rate form 10 bps to 40 bps coded telemetry, and to
turn the Radiometric calibration Test (RCT) NIMS heater on earlier than
planned.
2. The HGA diagnostic motor turn-on sequence memory load was sent to the
spacecraft on April 23, 1992. This sequence covers spacecraft activities from
April 27, 1992 to May 4, 1992. The motor turn-on for approximately 2 seconds
was performed on April 29, 1992 at 3:43 PDT. The Star Scanner (SS) checkout,
return to celestial reference and the wobble ID test are scheduled for
May 1, 1992.
3. The DMS recorder review was held on April 30, 1992. Past tape recorder
anomalies were reviewed and applicability to the Galileo design were discussed.
Analysis and test results were presented and concerns identified.
4. During the Earth-2 flyby, it is anticipated that asteroid Toutatis will be
tracked by the DSN (Deep Space Network). An RFI/EMC study has concluded there
is no threat to any Galileo spacecraft hardware from expected spacecraft
power density.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
|
| 560.649 | Updates - April 28 to May 1 | VERGA::KLAES | All the Universe, or nothing! | Fri May 01 1992 21:53 | 294 |
| Article: 860
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 04/28/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 29 Apr 1992 07:26:30 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 28, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, real time commands were sent to switch the telemetry rate from
10 bps to 40 bps coded telemetry. Additionally, under stored sequence control,
the Spacecraft was configured for the HGA (High Gain Antenna) diagnostic motor
turn on April 29, 1992.
Today, April 28, 1992, no Spacecraft activity or tracking is scheduled.
Tomorrow, under stored sequence control, the 2 second diagnostic HGA motor
turn-on is scheduled at 3:43 PDT. System shunt current telemetry will be
collected at the highest possible sample rate and stored on the tape recorder
(DMS) for playback later that evening. Tracking is scheduled over DSS-43
(Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 865
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/29/92
Date: 30 Apr 92 05:05:16 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 29, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no Spacecraft activity or tracking was scheduled.
Today, April 29, 1992, under stored sequence control, the 2 second
diagnostic HGA (High Gain Antenna) motor turn-on is scheduled at 3:43 PDT.
System shunt current telemetry will be collected at the highest possible sample
rate and stored on the tape recorder (DMS) for playback later this evening.
Tracking is scheduled over DSS-43 (Canberra 70 meter antenna).
Tomorrow, no Spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 868
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 04/30/92
Date: 1 May 92 00:04:14 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
April 30, 1992
The Galileo spacecraft is 382.7 million kilometers (238
million miles) from Earth, and 317 million kilometers or 197
million miles from the Sun. Round-trip communication time is
currently 42 minutes, 27 seconds. Since launch on October 18,
1989, Galileo has travelled just under 2 billion kilometers (1.25
billion miles) in its orbit. Speed in orbit now is 16.7
kilometers per second or 37,322 mph.
The spacecraft is operating normally in the all-spin mode,
spinning at about 2.89 rpm and transmitting coded telemetry at 40
bits per second.
Yesterday afternoon, operating under a stored sequence, the
high-gain antenna deploy motor was turned on for 2 seconds, in a
diagnostic procedure, for the first time since since the antenna
deployment attempt in April 1991. Antenna-rib release was not
expected from this activity; it was intended to provide
diagnostic data on the condition of the deployment system.
Engineering telemetry was tape-recorded and played back last
night; the flight team is now analyzing the data.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 869
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 04/30/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 1 May 1992 02:26:10 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 30, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, under stored sequence control, the 2 second diagnostic HGA
(High Gain Antenna) motor turn-on occurred at 3:43 PDT. Preliminary quick look
analysis of the shunt current playback data suggests the motor stalled within
approximately 100 milliseconds of turn-on. Detailed analysis is in process.
Telemetry indicates that the sun gate is still obscured, thus no rib released.
Today, April 30, 1992, no Spacecraft activity or tracking is scheduled.
Tomorrow, commands to checkout the star scanner and collect wobble ID data
are scheduled over DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 874
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #3 - 04/30/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 1 May 1992 07:33:56 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
April 24 - 30, 1992
SPACECRAFT
1. On April 27, as part of the HGA (High Gain Antenna) diagnostic motor
turn-on sequence activity, a science turn (SITURN) was commanded which oriented
the spacecraft to a 16-degree off earth pointed attitude (earth lagging) in
order to improve telecommunications (telecom) performance. Real-time commands
were then sent to change the telemetry rate from 10 bps to 40 bps coded
telemetry in support of the HGA diagnostic motor turn on April 29, 1992 (see
Special Topic 2).
2. On April 27, Delayed Action Commands (DACs) were sent to turn the
Radiometric Calibration Target (RCT) NIMS (Near Infrared Mapping Spectrometer)
heater on earlier than the planned turn-on in the HGA diagnostic motor turn-on
sequence. This will reduce the depth of the thermal cycle experienced by the
RCT-NIMS. The result will be that the heater will be off for 8 minutes instead
of 74 minutes; reducing the thermal cycle to 21 degrees C on May 1, 1992 (see
Special Topic 2).
3. On April 29, as part of the HGA diagnostic motor turn-on sequence activity,
the HGA motor was turned on at 22:43 UTC for approximately 2 seconds. The
system shunt current telemetry was collected at the highest possible sample
rate and stored on the tape recorder (DMS) for playback. The data was
subsequently played back between 23:00 UTC and 02:34 UTC. Initial sun gate
data indicates that the sun gate is still obscured, indicating no ribs
released. Subsequent "quick look" current analysis indicates that the motor
stalled within approximately 100 milliseconds of turn on. Detailed analysis
is in process (see Special Topic No. 2).
4. The AC/DC bus imbalance measurements exhibited some change. THe DC
measurement decreased 4 DN and reads 17.8 volts. The AC measurement remained
unchanged and reads 2.9 volts.
5. The Spacecraft status as of 1700 PDT April 30, 1992, is as follows:
a) System Power Margin - 30 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 5 degrees off sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 336 hours
Time To Initiation - 264 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-6 (Earth-Earth 6) Preliminary Sequence and command generation was
approved by the Project on April 29,1992. This sequence controls spacecraft
activities from May 11, 1992 to August 10, 1992.
TRAJECTORY
As of noon Thursday, April 30, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 237,800,000 miles (2.56 AU)
Distance from Sun 196,990,000 miles (2.12 AU)
Heliocentric Speed 36,800 miles per hour
Distance from Jupiter 691,320,000 miles
Round Trip Light Time 42 minutes, 42 seconds
SPECIAL TOPICS
1. As of April 30, 1992, a total of 7864 real-time commands have been
transmitted to Galileo since Launch. Of these, 3007 were pre-planned in the
sequence design and 4857 were not. In the past week, 5 real time commands were
transmitted; 3 were pre-planned in the sequence design and 2 were not. In
addition, 4204 mini-sequence commands have been transmitted since March 1991;
(1953 were pre-planned and 2251 were not). In the past week, no mini-sequence
commands were transmitted. Major command activities this week included commands
to: change the telemetry rate form 10 bps to 40 bps coded telemetry, and to
turn the Radiometric calibration Test (RCT) NIMS heater on earlier than
planned.
2. The HGA diagnostic motor turn-on sequence memory load was sent to the
spacecraft on April 23, 1992. This sequence covers spacecraft activities from
April 27, 1992 to May 4, 1992. The motor turn-on for approximately 2 seconds
was performed on April 29, 1992 at 3:43 PDT. The Star Scanner (SS) checkout,
return to celestial reference and the wobble ID test are scheduled for
May 1, 1992.
3. The DMS recorder review was held on April 30, 1992. Past tape recorder
anomalies were reviewed and applicability to the Galileo design were discussed.
Analysis and test results were presented and concerns identified.
4. During the Earth-2 flyby, it is anticipated that asteroid Toutatis will be
tracked by the DSN (Deep Space Network). An RFI/EMC study has concluded there
is no threat to any Galileo spacecraft hardware from expected spacecraft
power density.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 908
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/01/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 2 May 1992 04:56:35 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 1, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, April 30, 1992, no Spacecraft activity or tracking was
scheduled.
Today, May 1, 1992, commands to checkout the star scanner and collect
wobble ID data are scheduled over DSS-43 (Canberra 70 meter antenna).
Over the weekend, no Spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
|
| 560.650 | Updates - May 4-6 | VERGA::KLAES | All the Universe, or nothing! | Thu May 07 1992 22:02 | 93 |
| Article: 922
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/04/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 5 May 1992 07:48:28 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 4, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps (bits/second).
Over the weekend, no Spacecraft activity or tracking was scheduled.
Today, May 4, 1992, real-time commands to switch the telemetry rate to
10 bps coded telemetry were sent over DSS-14 (Goldstone 70 meter antenna).
Tomorrow, no Spacecraft activity is scheduled. Tracking is scheduled
over DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 931
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/05/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 6 May 1992 08:18:41 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 5, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, real-time commands to switch the telemetry rate to 10 bps
coded telemetry were sent.
Today, May 5, 1992, no Spacecraft activity is scheduled. Tracking is
scheduled over DSS-43 (Canberra 70 meter antenna).
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 941
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/06/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 7 May 1992 05:54:36 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 6, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, no Spacecraft activity was scheduled. Tracking was scheduled
over DSS-43 (Canberra 70 meter antenna).
Today, May 6, 1992, no Spacecraft activity or tracking is scheduled.
Tomorrow, the uplink of the EE-6 (Earth-Earth 6) sequence memory load is
scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
|
| 560.651 | Gaspra Sneak Peek | CARROL::LEPAGE | Jinky rules!!! | Tue May 12 1992 12:26 | 11 |
|
The lastest status reports on Galileo indicate that JPL controllers
will attempt a "sneak peek" at one of the high resolution Gaspra images
on the tape recorder today. The transmission rate will be temporarily
increased from 10 bps to 40 bps and tracking passes are scheduled
over DSS-63 (Madrid 70m), DSS-14 (Goldstone 70m), and DSS-43 (Canberra
70m). If they choose the right image (i.e. one with Gaspra actually in
the frame), we could soon have a full high resolution image of Gaspra.
Drew
|
| 560.652 | Updates - May 7-13 | VERGA::KLAES | All the Universe, or nothing! | Wed May 13 1992 21:47 | 231 |
| Article: 946
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/07/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 8 May 1992 04:46:22 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 7, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, no Spacecraft activity or tracking was scheduled.
Today, May 7, 1992, the uplink of the EE-6 (Earth-Earth 6) sequence
memory load is scheduled over DSS-43 (Canberra 70 meter antenna).
Tomorrow, no Spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 949
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 05/07/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 8 May 1992 09:01:12 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
May 1 - 7, 1992
SPACECRAFT
1. On May 1, as part of the HGA (High Gain Antenna) diagnostic motor turn-on
sequence activity, commands were sent to checkout and open the star scanner
shutter and to reacquire celestial reference. Additionally, the AACS (Attitude
and Articulation Control Subsystem) gyro-based wobble data was collected with
the spacecraft in the dual-spin mode. Analysis of the data indicates no change
in wobble corroborating the sun gate obscuration data (see Special Topic No. 2).
2. On May 4, real-time commands were sent to switch the telemetry rate from
40 bps to 10 bps coded telemetry in support of the EE-6 (Earth-Earth 6)
sequence memory load which goes active on May 10, 1992.
3. On May 7, the EE-6 sequence memory load was uplinked to the spacecraft.
The sequence was loaded on the spacecraft without incident.
4. The AC/DC bus imbalance measurements exhibited some change. THe DC
measurement decreased 2 DN and reads 17.5 volts. The AC measurement decreased
1 DN and reads 2.7 volts.
5. The Spacecraft status as of May 7, 1992, is as follows:
a) System Power Margin - 30 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.14 rpm/Star Scanner
d) Spacecraft Attitude is approximately 4 degrees off sun (leading)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 260 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-6 Final Sequence and command generation was approved by the Project
on May 6, 1992. This sequence controls spacecraft activities from May 11, 1992
to August 10, 1992.
TRAJECTORY
As of noon Thursday, May 7, 1992, the Galileo Spacecraft trajectory status
was as follows:
Distance from Earth 229,450,000 miles (2.47 AU)
Distance from Sun 195,140,000 miles (2.10 AU)
Heliocentric Speed 37,900 miles per hour
Distance from Jupiter 690,640,000 miles
Round Trip Light Time 41 minutes, 6 seconds
SPECIAL TOPICS
1. As of May 7, 1992, a total of 7902 real-time commands have been transmitted
to Galileo since Launch. Of these, 3045 were pre-planned in the sequence
design and 4857 were not. In the past week, 38 real time commands were
transmitted; 38 were pre-planned in the sequence design. In addition, 4204
mini-sequence commands have been transmitted since March 1991; (1953 were
pre-planned and 2251 were not). In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to:
checkout and open the star scanner shutter, change the telemetry rate from
40 bps to 10 bps coded telemetry, and uplink the EE-6 sequence memory load.
2. The HGA diagnostic motor turn-on sequence memory load was sent to the
spacecraft on April 23, 1992. This sequence covered spacecraft activities
from April 27, 1992 to May 4, 1992. The motor turn-on for approximately 2
seconds was performed on April 29, 1992 at 3:43 PDT. The Star Scanner (SS)
checkout, return to celestial reference and the wobble ID test were performed
on May 1, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 986
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 05/11/92
Date: 12 May 92 02:45:44 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 11, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Over the weekend, no Spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna) on Saturday.
Today, May 11, 1992, a science turn (SITURN) along with a tape recorder
(DMS) conditioning and routine science MRO's (Memory Readouts) are scheduled
over DSS-43 and DSS-63 (Madrid 70 meter antenna).
Tomorrow, the Gaspra high resolution DMS sneak peek activity along with
the routine RPM (Retro Propulsion Module) 10-Newton thruster "flushing"
maintenance activity and real-time commands to switch to 40 bps coded
telemetry are scheduled over DSS-63, DSS-14 (Goldstone 70 meter antenna) and
DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 990
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/12/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 13 May 1992 08:15:20 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 12, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Yesterday, a science turn (SITURN) along with a tape recorder (DMS)
conditioning and routine science MRO's (Memory Readouts) were performed.
Today, May 12, 1992, the Gaspra high resolution DMS sneak peek activity
along with the routine RPM (Retro Propulsion Module) 10-Newton thruster
"flushing" maintenance activity and real-time commands to switch to 40 bps
coded telemetry are scheduled. Tracking is scheduled over DSS-63 (Madrid
70 meter antenna), DSS-14 (Goldtone 70 meter antenna) and DSS-43 (Canberra 70
meter antenna).
Tomorrow, telecommunication (telecom) tests are scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
Article: 1017
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/13/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 14 May 1992 04:40:22 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 13, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the Gaspra high resolution DMS sneak peek activity was
performed. The Gaspra image was located in frame 37 of a 51 frame mosaic, as
anticipated. From its location in frame 37, we must replay parts of two
separate frames to capture the entire asteroid. Additionally, the routine
RPM (Retro Propulsion Module) 10-Newton thruster "flushing" maintenance
activity and real-time commands to switch to 40 bps coded telemetry were
executed as expected.
Today, May 13, 1992, telecommunication (telecom) tests are scheduled
over DSS-43 (Canberra 70 meter antenna).
Tomorrow, telecommunication tests along with cruise science Memory
Readouts (MROs) and a Ultra-Stable Oscillator (USO) test are scheduled.
Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna) and DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Denial is always the first
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | symptom.
|_____|/ |_|/ |_____|/ |
|
| 560.653 | Updates - May 15-29 | VERGA::KLAES | All the Universe, or nothing! | Wed Jun 03 1992 19:37 | 716 |
| Article: 1024
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/15/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 16 May 1992 01:44:36 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 15, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, telecommunication tests along with cruise science Memory
Readouts (MROs) and a Ultra-Stable Oscillator (USO) test were performed.
Today, May 15, 1992, no spacecraft activity or tracking is scheduled.
Over the weekend, real-time commands are scheduled to reposition the tape
recorder (DMS) for the high resolution Gaspra playback planned to begin on
May 18, 1992. Tracking is scheduled on Saturday over DSS-63 (Madrid 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1026
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 05/15/92
Date: 16 May 92 06:41:05 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
May 8 - 14, 1992
SPACECRAFT
1. On May 11, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
2. On May 11, a science turn (SITURN) was commanded which oriented the
spacecraft to a one degree off Earth pointed attitude (Earth lagging) to
improve telecommunications (telecom) performance in preparation for the high
resolution Gaspra image playback.
3. On May 11, a periodic Data Management Subsystem (DMS) conditioning
activity was performed and the tape was repositioned for the Gaspra "sneak
peek" activity planned for May 12.
4. On May 11, routine Extreme Ultraviolet Spectrometer (EUV) Memory Readouts
(MROs) were performed. The MROs were received without incident.
5. During the period of May 11 through May 12, a navigation cycle was
performed. The navigation cycle provided near-continuous acquisition of
two-way Doppler and ranging data during four consecutive passes of the
spacecraft over DSS-43 (Canberra 70 meter antenna), DSS-63 (Madrid 70 meter
antenna), DSS-14 (Goldstone 70 meter antenna), and then back to DSS-43.
Initial results indicated that the navigation cycle was successfully performed.
6. On May 12, a 10 bps modulation index test was performed to determine the
optimal Signal to Noise Ratio (SNR) at 10 bps. Data collected during this test
will help in selecting the modulation index which controls the data to carrier
power ratio and thus optimizes the SNR. Initial results indicate a 1.5db SNR
improvement at 10 bps.
7. On May 12, telemetry map changes were performed in preparation for
telecommunication (telecom) tests scheduled for the following day.
8. On May 12, real-time commands were sent switching the telemetry rate from
10 bps to 40 bps coded telemetry to support the Gaspra "sneak peek" activity.
9. On May 12, the periodic RPM (Retro Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed; 10 of the 12 thrusters were
flushed during the activity. The P-thrusters were not flushed because they
were used to perform science turn (SITURN) activities on May 11. Performance
of the thrusters was as expected.
10. On May 12, the Gaspra high resolution DMS sneak peek activity was
performed. Lines 336 through 354 and Lines 474 through 492 of frame 37, of
a 51 frame high resolution mosaic recorded during the Gaspra encounter, were
played back. The high resolution Gaspra image data was contained in both of
the memory readouts. This data when processed confirms that the majority of
the high resolution Gaspra picture is in the 37th frame with the remainder in
frame number 36 of the highest resolution Gaspra mosaic. The Project approved
repositioning the tape recorder and replay of lines 200 though 800 of frame
number 37. Plans for replay of frame number 36 will be developed next week
(Special Topic No. 2).
11. On May 13, a Command Detector Unit Signal to Noise Ratio (CDUSNR) test
along with a Radio Frequency Subsystem Automatic Gain Control (RFSAGC) test
were performed using LGA-1 (Low Gain Antenna) over DSS-43. Data is being
analyzed.
12. On May 14, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and collect gravitational red shift experiment
data. Data analysis is in process.
13. On May 14, a command threshold test was performed. Initial results
indicate the command threshold to be approximately -140 to -141 dbm
which is its nominal value.
14. On May 14, a Radio Frequency Subsystem Tracking Loop Capacitor (RFSTLC)
test was performed over DSS-43. Preliminary analysis indicates the capacitors
are operating normally.
15. On May 14, cruise science Memory Readouts (MROs) were performed for the
Dust Detector (DDS) and Magnetometer (MAG) instrument. Preliminary analysis
indicates the data was received properly.
16. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 1 DN and reads 17.7 volts. The AC measurement decreased
1 DN and reads 2.5 volts.
17. The Spacecraft status as of May 14, 1992, is as follows:
a) System Power Margin - 45 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 2 degree off sun (lagging)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 207 hours
TRAJECTORY
As of noon Thursday, May 14, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 220,794,000 miles (2.38 AU)
Distance from Sun 193,166,000 miles (2.08 AU)
Heliocentric Speed 38,400 miles per hour
Distance from Jupiter 689,789,000 miles
Round Trip Light Time 39 minutes, 40 seconds
SPECIAL TOPIC
1. As of May 14, 1992, a total of 7907 real-time commands have been
transmitted to Galileo since Launch. Of these, 3050 were pre-planned in the
sequence design and 4857 were not. In the past week, 5 real time commands
were transmitted; 5 were pre-planned in the sequence design. In addition,
4204 mini-sequence commands have been transmitted since March 1991; (1953 were
pre-planned and 2251 were not). In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer and change the telemetry rate from 10 bps to
40 bps coded telemetry.
2. The Gaspra high resolution DMS sneak peek activity to enable playback of
the high resolution Gaspra image was performed on May 12, 1992. The tape
recorder (DMS) repositioning for the high resolution image playback is
scheduled for May 16. The Memory Readouts will begin May 18, 1992 with
command windows through June 5, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1045
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/18/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 19 May 1992 04:33:16 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 18, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Over the weekend, real-time commands were sent to reposition the tape
recorder (DMS) for the high resolution Gaspra playback planned to begin today.
The tape recorder slewed approximately 30 Tape Increment Counts (TICs) to a
TIC position of 3768 which was the predicted value.
Today, May 18, 1992, high resolution Gaspra playbacks are scheduled.
Additionally, real-time commands are being sent to acquire Relay Radio
Antenna (RRA) potentiometer number 2 position data. Tracking is scheduled
over DSS-14, DSS-43, and DSS-63.
Tomorrow, high resolution Gaspra playbacks are scheduled. Tracking is
scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1052
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/19/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 20 May 1992 04:57:16 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 19, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40bps.
Yesterday, high resolution Gaspra playback data starting at line 198 of
frame number 37 was received. As of about 5 a.m. today approximately 25% of
frame number 37 has been received. Additionally, real-time commands were sent
to acquire Relay Radio Antenna (RRA) Potentiometer (POT) number 2 position and
calibration data. Potentiometer number 2 is consistent with POT number 1 data
implying that the RRA is deployed approximately 3.5 degrees out of its stowed
position.
Today, May 19, 1992, high resolution Gaspra playbacks continued. All
image data from frame 37 is expected to be on the ground for processing by
Friday, May 22, 1992. Tracking is scheduled over DSS-14 (Goldstone 70 meter
antenna) and DSS-63 (Madrid 70 meter antenna).
Tomorrow, high resolution Gaspra playbacks are scheduled. Additionally,
real-time commands are scheduled to reconfigure the Spacecraft telemetry to
the pre-RRA POT test reading. Tracking is scheduled over DSS-14, DSS-43, and
DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1058
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/20/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 22 May 1992 04:28:47 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 20, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps (bits/second).
Yesterday, high resolution Gaspra playbacks continued. Tracking was
performed over DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid 70 meter
antenna).
Today, May 20, 1992, high resolution Gaspra playbacks are continuing.
As of about 3 p.m. PDT today approximately 40% of frame number 37 planned for
replay will have been received on the ground. All image data from frame 37 is
expected to be on the ground for processing by Friday, May 22, 1992.
Additionally, real-time commands are being sent to reconfigure the Spacecraft
telemetry to the pre-RRA POT test reading. Tracking is scheduled over DSS-14,
DSS-43 (Canberra 70 meter antenna), and DSS-63.
Tomorrow, high resolution Gaspra playbacks are scheduled. Tracking is
scheduled over DSS-63 and DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1059
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/21/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 22 May 1992 04:30:07 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 21, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, high resolution Gaspra image playbacks continued without
problem. Tracking was performed over DSS-14 (Goldstone 70 meter antenna),
DSS-45 (Canberra 34 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, May 21, 1992, high resolution Gaspra image playbacks of Frame 37
will continue. Tracking is scheduled over DSS-43 and DSS-63.
Tomorrow, high resolution Gaspra playbacks of Frame 37 will continue.
Tracking is scheduled over DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1062
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 05/21/92
Date: 22 May 92 08:18:40 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
May 15 - 21, 1992
SPACECRAFT
1. On May 16, real-time commands were sent to reposition the tape recorder
(DMS) to line 200 of Frame 37 (of a 51 frame mosaic) in preparation for the
Gaspra high resolution image playback beginning on May 18. The tape recorder
slewed approximately 30 Tape Increment Counts (TICs) to a TIC position of 3768
which was the predicted value. The relationship between a specific TIC
position and a line count on a given SSI frame is plus or minus 10 lines.
2. On May 16, a delta Differenced One-Way Range (DOR) was performed over
DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Initial results indicate that the delta DOR was successfully performed.
3. On May 18, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
4. On May 18, commands were sent to acquire Relay Radio Antenna (RRA)
Potentiometer (POT) No. 2 calibration and position data. POT No. 2 telemetry
is consistent with the POT No. 1 reading, implying the RRA is deployed 3.5
degrees out of stow position.
5. On May 18, another delta Differenced One-Way Range (DOR) was performed
over DSS-14 and DSS-43 (Canberra 70 meter antenna). Initial results indicate
that the delta DOR was successfully performed.
6. On May 18, the Gaspra high resolution Data Memory Subsystem (DMS) Memory
Readouts (MROs) began. The MRO data of Frame 37 of the highest resolution
Gaspra mosaic started at line number 198. As of end of day Thursday (UTC time)
the data through line number 558 of Frame 37 has been received on the ground
for processing. The Gaspra image is estimated to be contained in 300 lines
of the 37th frame; line number 610 is estimated to be the last line containing
the Gaspra image. All image data from Frame 37 is predicted to be on the
ground for processing on Friday, May 22, 1992. Replay of the Frame 36 data
will begin Thursday, May 28, 1992 (Special Topic No. 2).
7. On May 20, commands were sent to reconfigure the spacecraft telemetry to
the pre-RRA POT test configuration which was conducted on May 18.
8. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 1 DN and reads 17.7 volts. The AC measurement decreased
1 DN and reads 2.5 volts.
9. The Spacecraft status as of May 21, 1992, is as follows:
a) System Power Margin - 45 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 5 degrees off
Earth (lagging) and 21 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 235 hours
TRAJECTORY
As of noon Thursday, May 21, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 211,862,000 miles (2.28 AU)
Distance from Sun 191,077,000 miles (2.06 AU)
Heliocentric Speed 39,000 miles per hour
Distance from Jupiter 688,769,000 miles
Round Trip Light Time 38 minutes, 4 seconds
SPECIAL TOPIC
1. As of May 21, 1992, a total of 7922 real-time commands have been
transmitted to Galileo since Launch. Of these, 3053 were pre-planned in the
sequence design and 4869 were not. In the past week, 5 real time commands were
transmitted; 15 were pre-planned; 3 were pre-planned in the sequence design.
In addition, 4204 mini-sequence commands have been transmitted since
March 1991; (1953 were pre-planned and 2251 were not). In the past week, no
mini-sequence commands were transmitted. Major command activities this week
included commands to reset the command loss timer and collect Relay Radio
Antenna (RRA) Potentiometer (POT) calibration and position data.
2. The Gaspra high resolution DMS sneak peek activity to enable playback of
the high resolution Gaspra image was performed on May 12, 1992. The tape
recorder (DMS) repositioning for the highest resolution image playback from
Frame 37 (about 80% of the Gaspra image) occurred on May 16. The Memory
Readouts (MROs) for Frame 37 began on May 18, 1992 and will complete on
May 27, 1992. The MROs for Frame 36 (about 20% of the Gaspra image) are
scheduled to begin on May 28, 1992 and continue until June 5, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1063
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/22/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 23 May 1992 02:42:27 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 22, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, high resolution Gaspra image playbacks of Frame 37 continued
without problem. Tracking was performed over DSS-43 (Canberra 70 meter
antenna) and DSS-63 (Madrid 70 meter antenna).
Today, May 22, 1992, high resolution Gaspra playbacks of Frame 37 will
continue. Tracking is scheduled over DSS-43 and DSS-63.
No Spacecraft activities are planned over the long weekend. Tracking is
scheduled on DSS-14 (Goldstone 70 meter antenna) on Saturday. Tracking will
resume early Tuesday morning, May 26, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1090
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/26/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 27 May 1992 05:27:16 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 26, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Over the weekend, no Spacecraft activities were scheduled. Tracking was
scheduled over DSS-14 (Goldstone 70 meter antenna) on Saturday.
Today, May 26, 1992, high resolution Gaspra playbacks of Frame 37 is
continuing. Tracking is scheduled over DSS-14 and DSS-43 (Canberra 70 meter
antenna).
Tomorrow, high resolution Gaspra playbacks of Frame 37 is scheduled to be
completed. Additionally, commands are scheduled to reposition the tape
recorder (DMS) for the high resolution Gaspra playbacks of Frame 36 which will
begin on Thursday, May 28, 1992. Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1094
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/27/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 28 May 1992 03:06:08 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 27, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, high resolution Gaspra playbacks of Frame 37 continued without
problem. Tracking was performed over DSS-14 (Goldstone 70 meter antenna)
and DSS-43 (Canberra 70 meter antenna).
Today, May 27, 1992, the high resolution Gaspra playback of Frame 37 is
scheduled to be completed at approximately 13:45 PDT. Additionally, commands
are scheduled to reposition the tape recorder (DMS) for the high resolution
Gaspra playbacks of Frame 36. Tracking is scheduled over DSS-43.
Tomorrow, high resolution Gaspra playbacks of Frame 36 is scheduled to
begin at approximately 08:33 PDT. Tracking is scheduled over DSS-14 and
DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1108
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/28/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 29 May 1992 14:03:17 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 28, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the high resolution Gaspra playback of Frame 37 was completed
without problem. Additionally, commands were sent to reposition the tape
recorder (DMS) for the high resolution Gaspra playbacks of Frame 36. The tape
recorder slewed 167 Tape Increment Counts (TICs) to a TIC position of 3663
which was the predicted value.
Today, May 28, 1992, high resolution Gaspra playbacks of Frame 36 are
scheduled to begin. Tracking is scheduled over DSS-14 (Goldstone 70 meter
antenna) and DSS-43 (Canberra 70 meter antenna).
Tomorrow, no Spacecraft activity or tracking is scheduled. The high
resolution Gaspra playbacks of Frame 36 are scheduled to continue Sunday
evening, May 31, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1111
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 05/29/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 30 May 1992 01:42:41 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 29, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps (bits/second).
Yesterday, high resolution Gaspra playbacks of Frame 36 began without
problem. Tracking was scheduled over DSS-14 (Goldstone 70 meter antenna)
and DSS-43 (Canberra 70 meter antenna).
Today, May 29, 1992, no Spacecraft activity or tracking is scheduled.
Over the weekend, high resolution Gaspra playbacks of Frame 36 are
scheduled to continue Sunday evening. Tracking is scheduled over DSS-63
(Madrid 70 meter antenna) on Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
Article: 1112
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 05/29/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 30 May 1992 02:20:49 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
May 22 - 28, 1992
SPACECRAFT
1. On May 26, a NO-OP command was sent to reset the command loss timer to 264
hours, its planned value for this mission phase.
2. On May 26, a routine sun vector update was performed. The sun vector is
valid through July 1, 1992.
3. On May 27, the Gaspra high resolution Data Memory Subsystem (DMS) Memory
Readouts (MROs) for Frame 37 were completed. Lines 198 through 801 of Frame 37
have been received on the ground for processing. The Gaspra image was
contained in about 253 lines of the 37th frame starting at Line 308 and ending
at approximately Line 560 (see Special Topic No. 2).
4. On May 27, real-time commands were sent to reposition the tape recorder
(DMS) to Line 211 of Frame 36 in preparation for continuing the Gaspra high
resolution image playback. The tape recorder slewed 167 Tape Increment Counts
(TICs) to a TIC position of 3663 which was the predicted value. The
relationship between a specific TIC position and a line count on a given SSI
(Solid State Imaging camera) frame is plus or minus ten lines (see Special
Topic No. 2).
5. On May 27, Delayed Action Commands (DACs) were sent to turn the
Radioisotope Thermoelectric Generator (RTG) boom heaters on May 28 and off
June 1 in order to lower the power margin and cool the Retro-Propulsion Module
(RPM) tanks prior to the scheduled thruster flushing activity on June 1.
6. On May 28, the Gaspra high resolution Data Memory Subsystem (DMS) Memory
Readouts (MROs) for Frame 36 began. The MRO data of Frame 36 started at Line
210. As of end of day Thursday (UTC time) the data through approximately Line
318 has been received on the ground for processing. The Gaspra image is
estimated to be contained in 243 lines of the 36th frame starting at Line 368
and ending at Line 610. All image data from Frame 36 is predicted to be on the
ground for processing on Wednesday, June 3, 1992 (see Special Topic No. 2).
7. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement decreased 3 DN and reads 16.8 volts. The AC measurement increased
3 DN and reads 3.1 volts.
8. The Spacecraft status as of May 28, 1992, is as follows:
a) System Power Margin - 28 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 8 degrees off
Earth (lagging) and 20 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 235 hours
GDS (Ground Data Systems):
1. Galileo participated in the May 27 Multimission Verification Test (MVT) at
Goldstone. The MVT was successful in demonstrating the data flow for all
Galileo data rates utilizing the new DSN (Deep Space Network) Telemetry
Processor Assembly (TPA) software version TPA OP-D/4.02. Frame sync was
maintained on all rates with the exception of 134.4kbps. The frame sync
problems seen at the 134.4kbps data rate are characteristic of DSN Simulation
System problems at that rate. Further analysis of the test results are in
progress.
TRAJECTORY
As of noon Thursday, May 28, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 202,688,000 miles (2.18 AU)
Distance from Sun 188,869,000 miles (2.03 AU)
Heliocentric Speed 39,700 miles per hour
Distance from Jupiter 687,573,000 miles
Round Trip Light Time 36 minutes, 26 seconds
SPECIAL TOPIC
1. As of May 28, 1992, a total of 7933 real-time commands have been
transmitted to Galileo since Launch. Of these, 3064 were pre-planned in the
sequence design and 4869 were not. In the past week, 11 real time commands
were transmitted; all were pre-planned in the sequence design. In addition,
4204 mini-sequence commands have been transmitted since March 1991; 1953 were
pre-planned and 2251 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer, reposition the tape recorder for Gaspra
playbacks, and turn the RTG boom heaters on and off.
2. The Gaspra high resolution DMS sneak peek activity to enable playback of
the high resolution Gaspra image was performed on May 12, 1992. The tape
recorder (DMS) repositioning for the highest resolution image playback from
Frame 37 (about 80% of the Gaspra image) occurred on May 16. The Memory
Readouts (MROs) for Frame 37 began on May 18, 1992 and completed on
May 27, 1992. The tape recorder positioning for Frame 36 (about 20 percent of
the Gaspra image) occurred on May 27. The MROs for Frame 36 (about 20% of the
Gaspra image) began on May 28, 1992 and will continue until June 5, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The Finagle Factor:
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Changing the universe to
|_____|/ |_|/ |_____|/ | fit the equation.
|
| 560.654 | Notes from the Gaspra News Conference | CARROL::LEPAGE | Jinky rules!!! | Fri Jun 12 1992 15:51 | 680 |
|
Gailileo Press Conference notes, 6/11/92
[
Usual disclaimers on accuracy, I don't work for NASA, only
~1/250millionth of NASA works for me - Jon
Crossposted to sci.space.news for benefit of people receiving
that group by email.
Some abbreviations used below:
DSN - Deep Space Network
HGA - High Gain Antenna
LGA - Low Gain Antenna
LNA - Low Noise Amplifier
S/C - Spacecraft
]
Galileo Gaspra Press Conference
Jet Propulsion Lab
June 11, 1992
Bob Macmillan, Public Information Officer
Good morning. Project team has several issues to discuss. First is
a new high resolution picture of asteroid Gaspra, returned in last
few weeks. Taken last October during high-velocity encounter.
Images available to press. Second, describe what kind of mission
can be done if HGA not released. Introduce first speaker: Dr.
Joseph Veverka of Cornell U.
Veverka: Thank you. Pleasure to be here representing imaging team. Lot
of data still on recorder, still playing it back.
Slide: Original Gaspra image
This is the picture played back in November, resolution
~165M/pixel. Pictures we'll see in a minute have resolution 3x
better. This is enough to show us shape, suggests it was derived
from larger objects by catastrophic collision. One thing we're
anxious about is to see some of surface in more detail. Expected
high resolution image to look something like this:
Slide: Coordinate system projection showing Gaspra orientation
What we actually saw is:
Slide: High-res image with overlaid coordinate grid
Projection was reasonably correct, determined it was rotating once
every 7 hours. For scale, about 18km long, this large crater is
about 1.5 km across. On right, latest idea of what asteroid looks
like from all directions:
Slide: Orthogonal 3-axis coordinate grid projection
So far we've seen only ~1/2 of Gaspra. More data on recorder, will
be played back later. So far we've done very, very well.
One thing we've discovered is a new class of feature called
grooves, seen on Phobos but not asteroids (though they had been
predicted). If you look at picture carefully - resolution about
50m - can see not only a multitude of craters but long, linear
depressions crossing the surface, ~300m across, 10-20m in depth.
We believe they're fractures.
Slide: Outline showing crossing grooves
Photos: Closeups of grooves.
These are believed to be expressions of fractures produced by
severe impacts, seen on Phobos:
Photo: Phobos image showing grooves
Slide: Phobos showing grooves clustering around large crater
Stickney
In this view, were able to confirm there are many, many small
craters on Gaspra - more than 600 counted so far. Largest ~1.5km
across, smallest ~100m across. If you were on Gaspra, these would
require an impactor ~10m across. What this suggests is that
population of impactors is dominated by small bodies - exciting
new discovery.
Slide: Approximates sizes and positions of craters on Gaspra.
Can model impactor population, come out to a surprising result:
has taken only ~200M years, very short in comparsion to age of
Gaspra.
Slide: Gaspra: History
Gaspra is a collisional gragment of a larger parent body
Shape determined by past catsatrophic collisons
Population of small craters accumulated since last
catastrophic event: some 200M years ago.
Slide: Gaspra: Collision history
100km progenitor
Collision events
Slide: S-Asteroids up close: Homogeneous or not?
Silicates and iron intimately mixed
Pure silicate and iron areas
We look for this by homogeneity and color.
Slide: Normalized spectral reflectance vs. wavelength
Dominant reflection near Olivene.
Already made 4-color image. To first order, found no large
variations in albedo and color - to show any variations, had to
produce false-color image. Small bluish and large reddish areas
you would see if your eyes were senstitive to IR.
One interesting question - bluish areas correspond to more
olivene, reddish less. Can map false color image onto new high-res
image. What do we see? Again, prominent bluish areas, more
olivene.
Slide: Gaspra: Color Summary
First approximation: Homogeneous
Subtle color variations occur
Related to topography (slopes)
Stronger Olivene signature on some slopes and around some
craters.
We're going to take a tour around Gaspra, if you were to fly
around asteroid.
Movie: Gaspra Topography: Galileo Imaging Team
[Image draped over recovered topography, rotating.
Vertical scale 1:1]
Project going very well. More data on tape recorder, returned in
Nov.
Slide: Gaspra: Imaging Objectives
1) High-resolution morphology
2) Color/Albedo patterns
3) Size/Shape/Rotation state
1 has been largely accomplished. 2 - a 6-color image at lower
resolution is still on tape recorder. 3 - data covering most of 7
hour rotation period on recorder. We have a lot of good data and
will be working very hard.
Bill O'Neil, project manager:
Good morning. Galileo is still doing very, very well. Flawlessly
executing flight plan.
Slide: Showing flight plan with timemarks and gravity assists.
Was 14 months ago, April '91, that we commanded HGA to deploy. Up
until that point, we'd been flying with HGA stowed under a tip
shade to protect it from solar heating in portions of early
trajectory inside Earth orbit.
Slide: Drawing showing S/C with antenna in stowed config.
Normally, would deploy into parabolic dish.
Slide: Drawing showing deployed configuration
Low-gain antenna located at top of HGA mast. Broadcasts over a
very wide beam; HGA concentrates into a very narrow beam
Slide: HGA vs. LGA lobe pattern
HGA is 10,000x intensity of LGA, so can acquire data at a much
higher rate.
Photo: flight antenna at Kennedy in final deployment before
installation.
We have an abundance of information, including telemetry and
ground analysis, that tells us HGA is in this configuration:
Photo: HGA partially deployed with 3 ribs stuck.
We've also concluded that the most likely reason for this is that
the locating pins that brace rib against tower for launch
vibrations, during ground transportation, had lubrication worn
away. Have extremely high friction in interface which is
preventing ribs from coming away.
Photo: Closeup of pins.
Have been doing warming/cooling turns to lengthen and shorten
tower in an attempt to get pins to walk out:
Slide: Flight plan showing warming/cooling turns with dates.
Have one more thermal cycle planned for end of this month and
first week of July. On 29 April, did turn on motors for 2 seconds
to verify antenna was in state we expected, and data shows it is
in that stalled configuration.
Note that when we attempted deployment, Galileo was at 1.3 AU from
Sun - considerably further from Sun than at launch. Not until we
get back to Earth for Earth II encounter do we have an opportunity
to get antenna as warm as it was for launch. Shortly after Earth
encounter, from Mid-Dec to Mid-Jan, can get antenna as warm as it
was at time we stowed it. Very good, exciting prospect determined
in ground testing that we can hammer deployment mechanism by
turning motors on and off 1-2000 times, more than doubling eject
force applied to ribs. That's our greatest prospect at this time.
In the event that's not successful, at Mar '93 we would have to
focus on implementing mission with LGA. Does not mean we would
give up on HGA, but would change emphasis. Basically this is our
decision point for mission we could do in event HGA could not be
deployed.
Slide: Spacecraft Status
Except for HGA, S/C is in excellent health
S/C performs all required functions beautifully
Orbiter science instruments demonstrated excellent
performance at Venus, Earth-1, and Gaspra
In-Flight probe checkouts nominal
Full S/C redudncany is intact
No known failures, not even a bad memory cell
[something I missed.]
Slide: Have always known we can
Get Galileo to Jupiter
Do entry probe mission
[something I missed]
Slide: We have found a way to accomplish the majority of the
orbiter science objectives, inlcuding return of several
thousand images.
Improvements in DSN will enable increasing LGA bit rate to
100 bps, a factor of 10.
Can program S/C central computer and attitude control
computer to do data compression that would reduce by a
factor of 10-20 the number of bits required to represent
an image.
Slide: Imaging Playback
High-level block diagram
Record 200-400 images/orbit on tape recorder.
Read segments into central computer. Transfer into
attitude control computer, compress, return to central
computer, downlink at ~100bps.
Can simultaneously return particles & fields data.
Slide: Typical Orbit ~1-2 months
In week closest to Jupiter and Galilean satellites, would
fill tape recorder and continue to return particles and
fields data.
For balance of orbit - orbital cruise - would go through
compression process to return data on recorder.
Dr. Leslie Deutsch
Manager of Telecommunications, [Data something]
We've been working with Galileo project since HGA failure to see
if we can improve performance. Basically have a healthy S/C which
needs help to achieve science objectives.
Will be using 4 separate techniques:
Slide: Array Antennas to capture more of the signal that gets
to Earth.
New developments since we used similar techniques to support
Voyager at Neptune. Can array at higher efficiency and more
antennas. Array within as well as between DSN complexes.
Slide: Increase the sensitivity of our Antennas
Photo - 70m Australia antenna
Australian antenna most important since Galileo appears in
Southern hemisphere during entire mission. Will be upgrading and
installing a low-noise amplifier. In addition, all antennas will
be equipped with a new set of receivers. Already planned to be
installed by Galileo tour period, but will be using in a new
configuration that will achieve 2x data rate.
Slide: Use more powerful error correcting codes.
With new codes, Galileo will be able to operate at a much
lower error rate while also allowing 50% higher data rate.
Error codes were first developed for use in deep space missions.
Basic point is to protect data so when it's corrupted by noise or
low signal strength, can still recover initial bits. Algorithm
appends a code word and transmits. On ground, decoder looks to see
what code word could have been, strip off extra bits and return
original bits to user. Galileo already has coders on board, but
new codes we will program will allow several magnitudes better
error correction while allowing 50% higher data rate.
Slide: Compression will allow information from Galileo to be
transmitted to Earth with many fewer bits.
Image compression - [looks like a discrete cosine
transform] - approximate transforms and send them to
Earth. Negligible loss of fidelity.
Lossless compression of other science data. Look for
patterns in data.
Compression ratio turns out to be 1.5-2:1 for lossless
compression. Much greater gains for imaging compression - 10-20:1.
In summary, would improve communications system using these four
techniques. Bottom line is a factor of 100 increase in science
information returned from Jupiter compared to current capability.
All these techniques come from ongoing research that will be used
in future missions.
Dr. Torrance Johnson, Project Scientist
My purpose is to describe what the expected science return from a
mission flown from the LGA would be. Science teams have been
working with our engineering colleagues since about last January.
We've concluded that by using techniques described previously, can
fly an excellent exploration mission at Jupiter and achieve
majority of science objectives.
Benchmark for our goals have been advances in knowledge about
Jupiter.
Slide: Galileo Science Objectives Advances over Voyager
Probe - first direct sampling of atmosphere
New Instruments - composition, spectral range, energy
ranges
Close Satellite Flybys - 100 to 1000x closer than Voyager
Time - 2 years in orbit vs. days to weeks in system
-----------------------------------------------------------
| All of these advantages are retained in the LGA mission |
-----------------------------------------------------------
What we have with LGA mission is a challenge to use resources
available to us in S/C and ground system to take advantage of
these elements of project. Don't have time to talk about all the
types of things we're thinking of doing with instruments. But one
of most important is use of advanced image compression techniques.
Similar techniques are used routinely on Earth these days. Would
like to demonstrate the power of these techniques. What we have
here is one frame from sequence Dr. Veverka showed. Original image
stretched to show detail on surface.
Photo: Gaspra image.
Performed an experiment, compressing this with algorithm described
by Les Deutsch.
Photo: Compressed and decompressed image.
Would challenge even those sitting in front row to tell any
difference. Even numerically, almost no loss. Totally acceptable,
can use images of this sort to achieve our objectives.
What this means is we can unload tape recorder in weeks instead of
years.
Slide: Project Galileo will investigate the...
Chemical composition and physical state of Jovian
atmosphere
Structure and physical dynamics of magnetosphere
Chemical composition and physical states of the Jovian
satellites
Slide: Atmospheric objectives
Probe
Composition
structture
Orbiter
Clouds
Structure
Composition
Orbiter
Dynamics (movies)
Major atmospheric experiment is probe itself, no loss. One
capability that does get lost is weather. Were planning to take
tens of thousands of images and make movies. Clearly we'll be
unable to do a lot of that. Will do some of limited regions of
atmosphere, without coverage we'd hoped for. Our estimate is that
by time we've done LGA mission, will have achieved 80% of
objectives.
Satellite Objectives
Io
Volcanoes
Atmosphere
Composiion
Europa
High-resolution
Surface processes
Tectonics
Ganymede
Composition
Mapping
Coverage
Callisto
Physical Properties
Gravity
Shape
Atmosphere
In satellite area, only need thousands of pictures, so it looks
better. Total and spectral coverage will suffer somewhat, but
overall, looking at highest priority objectives, don't take that
many pictures. Estimate we'll achieve at least 70% of objectives
in satellite area.
Final area is magnetosphere. Don't need pictures.
Slide: magnetospheric objectives
Structures, Dynamics "movies"
Composition
Io Torus
Composition
Processes
Processes
Satellite interactions
Will do most of these with slightly lower volumes of data.
Overall, 60% or more of objectives expected.
Slide: Science objectives summary
Atmospheric - 80% (probe mission unaffacted)
Satellites - 70% (don't need that many pictures)
Magentosphere - 60% (continuous coverage available)
Mission total - 70%
This is mavelous technology, even for those of us who work with it
frequently. But what will make LGA mission work is people. It will
be the women and men on the ground who will make it work if we
have to go this way.
Q&A:
Q (Lee Siegel, AP): On asteroid, when was image actually returned,
over what period, and would you care to update description as a
lizard?
On trying to salvage mission with LGA, what are cost implications?
How much will it add to cost of mission? What to you expect to
be the total number of images as opposed to what was planned.
Johnson: With respect to lizard, it's in the eye of the beholder,
changes when lighting conditions change.
O'Neil: Image was returned 18th, 20th, 21st of May. Other part was
1st-2nd June.
Q: What distance was that from?
O'Neil: About 1000 km, 1/3 of previous image.
Q: What was planned total of images at Jupiter vs what you expect?
Johnson: Total carried on books was ~50,000. Hadn't made detailed
plans even for HGA. Same for LGA: fundamental unit is one tape
recorder load/orbit. Made a guess that comes out to 2-4000.
Science teams will allocate images and other data to achieve
objectives.
Q: Cost implications? And salamander/ghoul? Need colorful description.
O'Neil: Won't take as many observations as planned. So uplink process
not nearly as demanding. Believe we can save enough on uplink
operations to account for increased downlink, no increase in
costs.
Johnson: Were going to leave it as an astronomical Rorsarch test,
reveal yourself by what you think it looks like.
Q (Annette Kondo [sp?], Star News): Wanted to get a better description
of last effort, max warm motor hammer done Dec-Jan '93. Can you
give another description of what will be done?
O'Neil: We have a pair of electric motors that drive a ball screw.
What we've determined in ground testing is that although antenna
is stalled and motors have driven as hard as they can, that by
pulsing motors repeatedly - 1-2000 times - can make screw turn
just a little more on each pulse. Turned screw 5 turns so far. Can
turn it another 1.5 turns in this attempt, which will double
forces trying to push out the stuck rib. So by hammering these
motors, e.g. turning them on and off for very short pulses, will
be able to increase forces in the deployment mechanism that's
trying to get these three ribs off the tower. If that's
successful, should be no further problems.
Q: That affects the ribs, not the pins?
O'Neil: Not directly. Push rods connected to base of ribs will push
harder, pulling harder on pins. Force on pins will double.
Q: Last-ditch effort to gyrate whole craft to shake ribs loose?
O'Neil: Quite some time ago, first extensive studies indicated very
little we could do in that regard - 2lb thrusters, 4,000 lb S/C.
Very little prospect for dynamic excitation. Based on what we've
just seen, will be very careful. Excellent mission without HGA, so
must not take significant risk. What we've been describing
presents no significant risks.
Q: I'm unclear on summary - result is factor of 100 increase in
science info. That's compared to current capability. But compared
to full HGA mission?
O'Neil: Believe we can do up to 70% of mission objectives. The other
thing you're referring to is that we can increase by 100x the
amount of information returned in new mode compared to what it
would be if we transmitted with LGA and no improvements.
Q: But what would it be compared to HGA mission?
O'Neil: About 70%.
Johnson: It's about a factor of 100 compared to what we're talking
about here.
Q (Judy Pasternak, LA Times): What are odds of getting HGA up?
O'Neil: We don't occupy ourselves trying to compute those odds.
There's no way to calculate such a number. We've been working very
vigorously to identify ways to release antenna. We've shown what
we plan to do. We'll continue to try to release the antenna. But
don't have odds.
Q (Siegel): *Up to* 70%, or 70%?
Johnson: Have only been working on this a short time. I am personally
confident - and BTW, while these techniques sound exotic, have
been doing them in labs for years - that we'll do *at least* 70%,
maybe more.
Q: Sceptical guy might say you're putting a happy face on situation.
What would you say to Joe Citizen who asks what his $1.4G is
doing?
Johnson: We're getting a heck of a return. Atmosphere probe for first
time. After first deployment failure, a lot of people had long
faces. Once we started realizing what capabilities were, people
started getting a lot more enthusiastic about prospects if HGA
does not deploy. Will be losing some things that require lots of
pictures - atmospheric dynamics and magnetosphereic dynamics - but
those are only partial objectives. Compare to Voyager: 100,000
pictures over course of project. All were valuable, but most major
discoveries are from literally only a few thousand of those
pictures. When you look at potential return, we're in very good
shape. Picture we just got back from Gaspra has already used some
of these techniques.
Veverka: Would like to add about Gaspra: have LGA mission, no loss of
science.
Q: What temperature do you hope to get LNAs down to? Is compression
comparable to JPEG?
Deutsch: Referring to 70m Australian antenna. Aiming for system
temperature of about 12K, about 3-4 degrees better than current
S-band systems. Our algorithm is based on JPEG, slightly different
transform to be implementable on Galileo. Have used S-band
amplifier before.
Q: How many pixels are in current image as compared to earlier image?
Veverka: 18km on long dimension, about 54m/pixel, low res image is 3x
coarser.
Q: Whether or not you've opened up the HGA, how many orbits around
Jupiter have you lost due to warming/cooling turns?
O'Neil: Have recently completed propellant analysis for tour. Can
complete all 10 - actually, now 11 - orbits and satellite
encounters, the full tour is intact. We also can go to Ida in
August '93. So bottom line is we have a margin of about 15kg
unallocated after having done all those things. It's true we have
expended propellant in thermal manuevers, but thanks to some
excellent improvements, we're confident we have a margin of about
15 kg. We expect to recommend we go to Ida - science group has
already made that recommendation to project - we need that
decision from HQ on July 1 and expect a favorable decision. 90%
confidence that we'll complete the 10 close encounters, which is
the number we've always used in propellant allocations.
Q (Science): Do you have an idea how much regolith is on Gaspra, and
to what degree it might be responsible for homogeneity.
Veverka: Still something we're working on. Additional information we
have is that in high-res images, some of topography is subdued,
which could be accounted for by regolith. Information is
consistent with there being some regolith. Key information from
NIMS instrument is still on tape recorder, will tell us once and
for all whether there's regolith, but right now, all indications
is there is a certain amount present.
Q (AP): I understand you don't want to put odds, but can you give us
your gut feel?
O'Neil: My gut feel is that I'm very anxious to see what motor hammer
will do for us. We've yet to do anything as authoritative as that.
I'm very pleased we have an excellent mission as it stands. Maybe
the answer you're looking for is, we're a long way from giving up.
We have good prospects. Hammering in Jan. is more authoritative,
more powerful than anything we've done, so certainly I'm
optimistic about that.
% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
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% From: leech@cs.unc.edu (Jon Leech)
% Subject: Gailileo Press Conference notes, 6/11/92
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|
| 560.655 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Fri Jun 12 1992 16:48 | 13 |
| Regarding the propellant: I don't believe I've seen it said specifically, but
I infer from this that they are giving up the second asteroid encounter on the
way out?
Regarding the news conference in general: They sure misunderstood a lot of
questions! They never answered the question about additional cost, and it
seemed clear to me that they were being asked "You increased the effective data
rate by a factor of 100 over the LGA-as-it-stands-now. Compare that with the
effective data rate planned over the HGA." They kept insisting on answer the
also interesting but different question of "What % of the mission goals will be
accomplished".
Burns
|
| 560.656 | Gaspra images available | PRAGMA::GRIFFIN | Dave Griffin | Fri Jun 12 1992 17:17 | 9 |
| Two new Gaspra images (mentioned in recent replies) are available:
pragma::public:[nasa]gal_gaspra_3.gif
4
They also have caption files, same file names with the extension: .info
- dave
|
| 560.657 | So near yet so far | AUSSIE::GARSON | | Mon Jun 15 1992 04:04 | 38 |
| re .656
>Two new Gaspra images (mentioned in recent replies) are available:
>
> pragma::public:[nasa]gal_gaspra_3.gif
> 4
The program XGIF that I liberated from PRAGMA:: some time ago used to work
but no more.
Does anyone understand the following gibberish?
Know what to do to make it work?
Have pointer to working program?
$1$dua210:[garson.images]xgif.exe;1: gal_gaspra_3.gif is 640x480, 256 colors
(of which 208 are used)
$1$dua210:[garson.images]xgif.exe;1: gal_gaspra_3.gif stripped 5 bits
X error event received from server: BadMatch - parameter mismatch
Failed request major op code 72 (X_PutImage)
Failed request minor op code 0 (if applicable)
ResourceID 0x0 in failed request (if applicable)
Serial number of failed request 1567
Current serial number in output stream 1586
%XLIB-E-ERROREVENT, error event received from server
%TRACE-E-TRACEBACK, symbolic stack dump follows
module name routine name line rel PC abs PC
0002540C 0002540C
00025231 00025231
00026A67 00026A67
00026E0D 00026E0D
00024164 00024164
XGIF main 2787 0000046C 0000B06C
:
:
:
VMS V5.4-3
Display is set to a VAXstation 2000 running EWS
|
| 560.658 | Ida Flyby Likely | CARROL::LEPAGE | Jinky rules!!! | Mon Jun 15 1992 12:33 | 10 |
| Re:.655
Actually, it was specificly mentioned that they are recommending to
NASA Headquarters that they be given the OK for the Ida encounter. It
appears very likely the flyby will be approved. All the discussion
concerning the propellant margins for 10 or 11 satellite encounters was
based on the assumption that the Ida flyby takes place.
Drew
|
| 560.659 | Re: .657 | PRAGMA::GRIFFIN | Dave Griffin | Mon Jun 15 1992 13:25 | 12 |
| >X error event received from server: BadMatch - parameter mismatch
> Failed request major op code 72 (X_PutImage)
> Failed request minor op code 0 (if applicable)
> Display is set to a VAXstation 2000 running EWS
I don't claim to know a lot about these things, but it would appear to me that
your EWS X Server can't handle a particular X_PutImage call that XGif forms.
- dave
|
| 560.660 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Mon Jun 15 1992 16:52 | 4 |
| re IDA: Thanks. I found it this time. Brain must have been in neutral when I
was reading.
Burns
|
| 560.661 | Information on new Gaspra images | VERGA::KLAES | All the Universe, or nothing! | Tue Jun 16 1992 00:18 | 134 |
| Article: 23554
Newsgroups: sci.space,sci.astro,sci.geo.geology
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Gaspra GIFs Available
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 12 Jun 1992 06:24:48 GMT
==========================
GASPRA GIF IMAGES
June 11, 1992
==========================
The two high resolution Gaspra images released at the press conference
today are now available in GIF format. The two images were scanned in from
photographs, and are not the raw data. There are also two caption files
accompanying the images, and I've appended them to end of this message.
The files are available using anonymous ftp to:
ftp: ames.arc.nasa.gov (128.102.18.3)
user: anonymous
cd: pub/SPACE/GIF
files:
gaspra2.gif (B/W)
gaspra2.txt (Caption file for)
gaspra3.gif (Color)
gaspra3.txt (caption file)
-------------------------------------------------------------------
GASPRA2.TXT
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
PHOTO CAPTION GALILEO
June 11, 1992 P-40449
TOP GLL/GA4
This picture of asteroid 951 Gaspra is a mosaic of two images
taken by the Galileo spacecraft from a range of 5,300 kilometers
(3,300 miles), some 10 minutes before closest approach on October 29,
1991. The Sun is shining from the right; phase angle is 50 degrees.
The resolution, about 54 meters/pixel, is the highest for the Gaspra
encounter and is about three times better than that in the view
released in November 1991. Additional images of Gaspra remain stored
on Galileo's tape recorder, awaiting playback in November.
Gaspra is an irregular body with dimensions about 19 x 12 x 11
kilometers (12 x 7.5 x 7 miles). The portion illuminated in this view
is about 18 kilometers (11 miles) from lower left to upper right. The
north pole is located at upper left; Gaspra rotates counterclockwise
every 7 hours. The large concavity on the lower-right limb is about 6
kilometers (3.7 miles) across, the prominent crater on the terminator,
center left, about 1.5 kilometers (1 mile).
A striking feature of Gaspra's surface is the abundance of small
craters. More than 600 craters, 100-500 meters (330-1650 feet) in
diameter are visible here. The number of such small craters compared
to larger ones is much greater for Gaspra than for previously studied
bodies of comparable size such as the satellites of Mars.
Gaspra's very irregular shape suggests that the asteroid was
derived from a larger body by nearly catastrophic collisions.
Consistent with such a history is the prominence of groove-like linear
features, believed to be related to fractures. These linear
depressions, 100-300 meters wide and tens of meters deep, are in two
crossing groups with slightly different morphology, one group wider
and more pitted than the other. Grooves had previously been seen only
on Mars's moon Phobos, but were predicted for asteroids as well.
Gaspra also shows a variety of enigmatic curved depressions and ridges
in the terminator region at left.
The Galileo project, whose primary mission is the exploration of
the Jupiter system in 1995-97, is managed for NASA's Office of Space
Science and Applications by the Jet Propulsion Laboratory.
---------------------------------------------------------------------------
GASPRA3.TXT
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
PHOTO CAPTION GALILEO
June 11, 1992 P-40450-C
TOP GLL/GA5
This picture of asteroid 951 Gaspra is a combination of the
highest-resolution morphology and color information obtained by the
Galileo spacecraft during its approach to the asteroid on October 29,
1991. The Sun is shining from the right; phase angle is 50 degrees.
The base image is the best black-and-white view of Gaspra (resolution
54 meters/pixel) on which are superimposed the subtle color variations
constructed from violet, green, and near-infrared (1000 nanometers)
inages taken in an earlier sequence at a resolution about 164 meters/pixel.
The very subtle color variations on Gaspa's surface have been
artificially exaggerated here; to first order Gaspra's color is fairly
homogeneous over the surface. However, subtle albedo and color
variations do occur and are correlated with surface topography in a
significant way. In this false-color view, the bluish areas represent
regions of slightly higher albedo, which are also regions of slightly
stronger spectral absorption near 1000 nanometers, probably due to the
mineral olivine. These bluish areas tend to be associated with some
of the crisper craters and with ridges. The slightly reddish areas,
apparently concentrated in topographic lows, represent regions of
somewhat lower albedo and weaker absorption near 1000 nanometers. In
general, such patterns can be explained in terms of greater exposure
of fresher rock in the brighter bluish areas and the accumulation of
some regolith materials in the darker reddish areas.
Gaspra is an irregular body with dimensions about 19 x 12 x 11
kilometers (12 x 7.5 x 7 miles). The portion illuminated in this view
is about 18 kilometers (11 miles) from lower left to upper right.
This color picture results from a joint effort by image
processing groups at the U. S. Geological Survey in Flagstaff,
Arizona, Cornell University in Ithaca, New York, and JPL. The Galileo
project, whose primary mission is the exploration of the Jupiter
system in 1995-97, is managed for NASA's Office of Space Science and
Applications by the Jet Propulsion Laboratory.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
|
| 560.662 | Updates - June 9-15 | VERGA::KLAES | All the Universe, or nothing! | Tue Jun 16 1992 22:37 | 187 |
| Article: 1159
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/09/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 10 Jun 1992 02:15:50 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 9, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, no spacecraft activity was scheduled. Tracking was performed
over DSS-43 (Canberra 70 meter antenna).
Today, June 9, 1992, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
Tomorow, no spacecraft activity is scheduled. Tracking will continue
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1169
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/10/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 11 Jun 1992 04:39:31 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 10, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, no spacecraft activity was scheduled. Tracking was performed
over DSS-43 (Canberra 70 meter antenna).
Today, June 10, 1992, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
Tomorrow, no spacecraft activity is scheduled. Tracking will continue
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1196
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/12/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 13 Jun 1992 06:12:53 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
June 4 - 11, 1992
SPACECRAFT
1. On June 5, the Gaspra high resolution Data Memory Subsystem (DMS) Memory
Readouts (MROs) for Frame 36 completed at approximately 01:21 UTC. All Gaspra
imaging and NIMS (Near Infrared Mapping Spectrometer) data was received and
processed although 8 minutes of data was lost due to a DSS-43 (Canberra 70
meter antenna) problem at the end of the MRO (Memory Readout). This equated
to about a 99.9 percent return of the requested data (see Special Topic No. 2).
2. On June 8, a NO-OP command was sent to reset the command loss timer to 264
hours, its planned value for this mission phase.
3. During the week, the DC bus imbalance reading has continued to change
significantly. The DC measurement has ranged from 5 DN (O volts) to 109 DN
(12.7 volts) and reads 37 DN (3.9 volts). This measurement variation is
consistent with the model developed by the AC/DC special anomaly team. The
AC measurement has remained relatively stable and reads 15 DN (3.5 volts).
4. The Spacecraft status as of June 11, 1992, is as follows:
a) System Power Margin - 16 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 14 degrees off
Earth (lagging) and 16 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 186 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The High Gain Antenna (HGA) Warming/Cooling Turn 6A command generation
product was approved by the Project on June 5, 1992. This mini-sequence covers
spacecraft activity from June 29 to July 10, 1992.
TRAJECTORY
As of noon Thursday, June 11, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 183,780,000 miles (1.98 AU)
Distance from Sun 184,098,000 miles (1.98 AU)
Heliocentric Speed 41,100 miles per hour
Distance from Jupiter 684,632,000 miles
Round Trip Light Time 33 minutes, 4 seconds
SPECIAL TOPIC
1. As of June 11, 1992, a total of 7945 real-time commands have been
transmitted to Galileo since Launch. Of these, 3076 were pre-planned in the
sequence design and 4869 were not. In the past week, one real time command was
transmitted and was pre-planned in the sequence design. In addition, 4204
mini-sequence commands have been transmitted since March 1991; 1953 were
pre-planned and 2251 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer.
2. The Gaspra high resolution DMS sneak peek activity to enable playback of
the high resolution Gaspra image was performed on May 12, 1992. The tape
recorder (DMS) repositioning for the highest resolution image playback from
Frame 37 (about 80% of the Gaspra image) occurred on May 16. The Memory
Readouts (MROs) for Frame 37 began on May 18, 1992 and completed on
May 27, 1992. The tape recorder positioning for Frame 36 (about 20 percent of
the Gaspra image) occurred on May 27. The MROs for Frame 36 began on
May 28, 1992 and completed on June 5, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1203
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/15/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 16 Jun 1992 00:09:30 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 15, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity or tracking was scheduled.
Today, June 15, 1992, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43 (Canberra 70 meter antenna).
Tomorrow, no spacecraft activity is scheduled. Tracking will continue
over DSS-43 and DSS-63 (Madrid 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
|
| 560.663 | Updates - June 16-19 | VERGA::KLAES | All the Universe, or nothing! | Sat Jun 20 1992 19:47 | 211 |
| Article: 1217
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/16/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 17 Jun 1992 08:09:48 GMT
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
June 16, 1992
The Galileo spacecraft is less than 285 million kilometers (about
177 million miles) from Earth; each day, that distance decreases by
more than 2 million kilometers. The distance from the Sun is 293
million kilometers or 182 million miles. Galileo's speed in its solar
orbit is now 18.6 kilometers per second, nearly 42,000 mph, increasing
by more than 100 mph each day.
Spacecraft health and performance continue to be excellent,
except for the undeployed high-gain antenna. The spacecraft is in
dual-spin, with the upper body spinning at 3.15 rpm and the lower part
despun or fixed in space. The spacecraft is transmitting coded
telemetry at 40 bits per second, making and storing measurements of
the space environment, and conducting scheduled engineering tests and
maintenance operations. Another warming/cooling cycle, part of the
planned effort to free the stuck ribs of the high-gain antenna, is
scheduled to start late this month.
Last week the project released the highest-resolution picture of
Gaspra, taken last October 29 when Galileo made the first-ever
asteroid flyby. Several low-resolution images, and the rest of the
observational data, are still in the spacecraft tape recorder, and
will be played back in November. Also last week, the project
discussed plans to recover most of Galileo's Jupiter science mission
in the event the high-gain antenna remains stuck. They would use
recent and ongoing developments in data-processing and enhanced ground
hardware to send several thousand high-resolution pictures and a wealth
of other science data while the spacecraft orbits Jupiter in 1995-97.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1219
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/17/29
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 18 Jun 1992 00:01:38 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 17, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, no spacecraft activity was scheduled. Tracking was performed
over DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, June 17, 1992, no spacecraft activity or tracking is scheduled.
Tomorrow, Delayed Action Commands (DAC) are scheduled to be sent to
maintain the appropriate power margin and thermal control of Retro-Propulsion
Module (RPM) tanks. Tracking is scheduled over DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1235
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 06/18/92
Date: 19 Jun 92 08:59:50 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 18, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, no spacecraft activity or tracking was scheduled.
Today, June 18, 1992, Delayed Action Commands (DAC) are scheduled to be
sent to maintain the appropriate power margin and thermal control of the
Retro- Propulsion Module (RPM) tanks. Tracking is scheduled over DSS-43
(Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Tomorrow, no spacecraft activity is scheduled. Tracking will continue
over DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1239
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 06/19/92
Date: 20 Jun 92 01:19:27 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
June 12 - 18, 1992
SPACECRAFT
1. On June 15, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
2. On June 18, Delayed Action Commands (DACs) were sent to turn off the
Photometric Calibration Target (PCT) No. 1 and No. 2, and the external shunt
heater No. 1A on June 22; as well as turn on the Photometric Calibration
Target (PCT) No. 1 and No. 2, the contamination monitor on, and the external
shunt heater No. 1A off June 29. These commands were sent to maintain the
appropriate power margin and thermal control of the Retro-Propulsion Module
(RPM) tanks in preparation for the scheduled HGA (High Gain Antenna) turn
sequence No. 6A activity from June 29 to July 10.
3. During the period of June 18 through June 19, a navigation cycle is being
performed. This navigation cycle is providing near-continuous acquisition of
two-way Doppler and ranging data during three consecutive passes of the
spacecraft over DSS-43, DSS-63, and DSS-14 (all three 70 meter antennas at
Canberra, Madrid and Goldstone, respectively).
4. During the week, the DC bus imbalance reading has continued to change
significantly. The DC measurement has ranged from 37 DN (3.9 volts) to
112 DN (13.0 volts) and now reads 53 DN (5.8 volts). This measurement
variation is consistent with the model developed by the AC/DC special anomaly
team. The AC measurement has remained relatively stable and reads 15 DN
(3.5 volts).
5. The Spacecraft status as of June 11, 1992, is as follows:
a) System Power Margin - 16 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 17 degrees off
Earth (lagging) and 14 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 261 hours
TRAJECTORY
As of noon Thursday, June 18, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 174,138,000 miles (1.87 AU)
Distance from Sun 181,534,000 miles (1.95 AU)
Heliocentric Speed 41,800 miles per hour
Distance from Jupiter 682,875,000 miles
Round Trip Light Time 31 minutes, 20 seconds
SPECIAL TOPIC
1. As of June 18, 1992, a total of 7960 real-time commands have been
transmitted to Galileo since Launch. Of these, 3091 were pre-planned in the
sequence design and 4869 were not. In the past week, 15 real time commands
were transmitted and were pre-planned in the sequence design. In addition,
4204 mini-sequence commands have been transmitted since March 1991; 1953 were
pre-planned and 2251 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer, and to maintain the proper power margin and
thermal control.
2. The HGA technical workshop was held at JPL on June 17 and 18. The workshop
was convened to perform an independent review and assessment of all the HGA
anomaly related efforts to date. Members included experts from the aerospace
industry, other NASA centers, universities, ESA, and Department of Defense
facilities.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
|
| 560.664 | Updates - June 23 to July 9 | VERGA::KLAES | Slaves to the Metal Hordes | Fri Jul 10 1992 18:47 | 664 |
| Article: 1254
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/23/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 24 Jun 1992 05:09:16 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 23, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the routine RPM (Retro-Propulsion Module) 10-Newton thruster
"flushing" maintenance activity, cruise science Memory Readouts (MROs), and a
science turn (SITURN) were performed. Tracking was performed over DSS-43
(Canberra 70 meter antenna).
Today, June 23, 1992, delta Differenced One-Way Range (DOR) passes are
being performed over DSS-14/63 (Goldstone/Madrid 70 meter antennas) and
DSS-14/43 (Goldstone/Canberra 70 meter antennas).
Tomorrow, a 40 bps mod index telecommunication (telecom) test and
Ultra-Stable Oscillator (USO) test are scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1278
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/25/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 26 Jun 1992 00:28:51 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 25, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps (bits/second).
Yesterday, a 40 bps mod index telecommunication (telecom) test and
Ultra-Stable Oscillator (USO) test were performed over DSS-43 (Canberra 70
meter antenna), as planned.
Today, June 25, 1992, the uplink of the HGA (High Gain Antenna) turn
sequence No. 6A is being performed. Tracking is scheduled over DSS-43 and
DSS-63 (Madrid 70 meter antenna).
Tomorrow, spacecraft activity is limited to radio navigation activities.
Tracking is scheduled over DSS-63, DSS-14 (Goldstone 70 meter antenna), and
DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1302
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 06/26/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 27 Jun 1992 06:41:57 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
June 19 - 25, 1992
SPACECRAFT
1. On June 22, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
2. On June 22, routine Extreme Ultraviolet Spectrometer (EUV) Memory Readouts
(MROs) were performed. The MROs were received without incident.
3. On June 22, the periodic RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed. All 12 thrusters were flushed
and their performance was as expected.
4. On June 22, a science turn (SITURN) was scheduled to ensure the spacecraft
was at the appropriate attitude to guarantee 40 bps telemetry during the EE-6
(Earth-Earth 6) sequence. The P-thrusters fired four times bringing the HGA
(High Gain Antenna) pointing error down from 8.3 milliradians to less than
0.5 milliradian.
5. On June 22, the earth vector and earth stars were updated to the
spacecraft's present attitude. This strategy is being employed such that if
spacecraft safing is invoked, the spacecraft will remain at the current
attitude instead of going to sun point. This will expedite spacecraft
recovery in the event of spacecraft safing.
6. On June 23, delta Differenced One-Way Range (DOR) passes were performed
over DSS-14/63 and DSS 14/43. Initial results indicate that the delta DORs
were successfully performed.
7. On June 24, a 40 bps modulation index test was performed to determine the
optimal Signal-to-Noise Ratio (SNR) at 40 bps. Analysis of the test data
indicates that the present mod index selected pre-launch is very near the
optimum level.
8. On June 24, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and collect gravitational red shift experiment
data; long term trend analysis is continuing.
9. On June 25, the Warming/Cooling Turn No 6A sequence memory load was sent
to the spacecraft. The sequence was loaded on the spacecraft without incident
(see Special Topic No. 2).
10. On June 25, cruise science Memory Readouts (MROs) were performed for the
Dust Detector (DDS) and Magnetometer (MAG) instruments. Preliminary analysis
indicates the data was received properly.
11. During the period of June 25 through June 26, a navigation cycle is being
performed. This navigation cycle is providing near-continuous acquisition of
two-way doppler and ranging data during four consecutive passes of the
spacecraft over DSS-43, DSS-63, DSS-14, and then back to DSS-43. This data
will improve orbit determination in preparation for the TCM-14 (Trajectory
Correction Maneuver 14) maneuver scheduled for the August 4 through 7 time
period.
12. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 20 DN and reads 8.3 volts. The AC measurement decreased
2 DN and reads 3.1 volts.
13. The Spacecraft status as of June 25, 1992, is as follows:
a) System Power Margin - 25 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 20 degrees off
Earth (lagging) and 12 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- EUV, DDS, MAG, UVS, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 258 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Warming/Cooling Turn No. 6A mini-sequence was approved for transmission
by the Project on June 24, 1992. This mini-sequence covers spacecraft
activities from June 29 through July 10 (see Special Topic No. 2).
TRAJECTORY
As of noon Thursday, June 25, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 164,417,000 miles (1.77 AU)
Distance from Sun 178,850,000 miles (1.93 AU)
Heliocentric Speed 42,600 miles per hour
Distance from Jupiter 680,917,000 miles
Round Trip Light Time 29 minutes, 36 seconds
SPECIAL TOPIC
1. As of June 25, 1992, a total of 7961 real-time commands have been
transmitted to Galileo since Launch. Of these, 3092 were pre-planned in the
sequence design and 4869 were not. In the past week, one real time command
was transmitted and was pre-planned in the sequence design. In addition, 4534
mini-sequence commands have been transmitted since March 1991; 2283 were
pre-planned and 2251 were not. In the past week, 330 mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer and uplink the HGA Warming/Cooling Turn 6A
sequence memory load.
2. The HGA Warming/Cooling Turn 6A activities are scheduled from June 29 to
July 10. The warming turn will be performed on June 29 and the spacecraft will
remain at the warming attitude for approximately 47 hours. The spacecraft
return from the warming attitude is scheduled for July 1. A star scanner
checkout, along with collection of sun gate and wobble ID data will occur on
July 2. The spacecraft bus cool down period will also start on July 2 and
complete on July 6. The cooling turn will be performed on July 6 and the
spacecraft will remain at the cooling attitude for approximately 44 hours.
The spacecraft return from the cooling attitude will occur on July 8. The
star scanner checkout, along with collection of sun gate and wobble ID data is
scheduled during the July 9-10 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1303
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/26/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 27 Jun 1992 06:06:23 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 26, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps (bits/second).
Yesterday, the uplink of the HGA (High Gain Antenna) turn sequence No. 6A
was completed as planned. Tracking was scheduled over DSS-43 (Canberra 70
meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, June 26, 1992, spacecraft activity is limited to radio navigation
activities. Tracking is scheduled over DSS-63, DSS-14 (Goldstone 70 meter
antenna), and DSS-43.
Over the weekend, no spacecraft activity or tracking is scheduled. The
turn to the warming attitude is scheduled for Monday, June 29, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1322
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 06/29/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 30 Jun 1992 01:40:11 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 29, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Over the weekend, no spacecraft activity or tracking was scheduled.
Today, June 29, 1992, the turn to the warming attitude is scheduled to
begin at approximately 11:10 PDT. The spacecraft will remain at the warming
attitude for approximately 47 hours. Tracking is scheduled over DSS-43
(Canberra 70 meter antenna).
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1336
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 06/30/92
Date: 1 Jul 92 01:17:23 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 30, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the turn to the warming attitude began at 11:14 PDT and
completed at 11:39 PDT, as planned. The spacecraft will remain at the warming
attitude for approximately 47 hours. Tracking was scheduled over DSS-43
(Canberra 70 meter antenna).
Today, June 30, 1992, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
Tomorrow, the spacecraft is scheduled to return from the warming attitude
beginning at approximately 11:19 PDT. Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Pound for pound,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | grasshoppers are 3 times as
|_____|/ |_|/ |_____|/ | nutritious as beef.
Article: 1347
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/01/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 2 Jul 1992 01:35:11 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 1, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 40bps.
Yesterday, no spacecraft activity was scheduled. Tracking was performed
over DSS-43 (Canberra 70 meter antenna).
Today, July 1, 1992, the spacecraft is scheduled to return from the
warming attitude beginning at approximately 11:19 PDT. The sun acquisition to
a 5-degree off-sun attitude will complete at approximately 11:50 PDT and sun
gate data will be received beginning at approximately 12:04 PDT. Tracking is
scheduled over DSS-43.
Tomorrow, the star scanner checkout and wobble ID are scheduled along
with switching telemetry rates from 40 bps coded to 10 bps coded and beginning
the pre-cool portion of cooling turn No. 6A. Tracking is scheduled over
DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1357
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 07/02/92
Date: 3 Jul 92 00:51:46 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 2, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the spacecraft return from the warming attitude began at
approximately 11:19 PDT and completed at approximately 11:50 PDT, as planned.
Initial sun gate data analysis indicates the sun gate is still obscured,
confirming no ribs released. Tracking was performed over DSS-43 (Canberra
70 meter antenna).
Today, July 2, 1992, the star scanner checkout and wobble ID are
scheduled along with switching telemetry rates from 40 bps coded to 10 bps
coded and beginning the pre-cool portion of cooling turn No. 6A. Tracking is
scheduled over DSS-43.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled over
DSS-43. The pre-cool portion of cooling turn No. 6A will continue throughout
the weekend with no spacecraft activity or tracking scheduled until Monday,
July 6, 1992.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1364
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 07/02/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 3 Jul 1992 05:45:58 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
June 26 - July 2, 1992
SPACECRAFT
1. On June 29, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
2. On June 29, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV). The MROs were received as planned.
3. On June 29, real-time commands were sent to change the System Fault
Protection (SFP) AACS-INIT (Attitude and Articulation Control Subsystem)
pointing slot from the Earth to the Sun prior to the High Gain Antenna (HGA)
No. 6A warming turn. This change will allow the spacecraft to return to a
sun-pointed attitude if an AACS Power On Reset (POR) occurs during the HGA
Warming/Cooling Turn No. 6A activities.
4. On June 29, the Warming/Cooling Turn No. 6A sequence memory load went
active. The warming turn to a 45-degree off-sun attitude commenced at
approximately 1814 UTC and completed at 1839 UTC (See Special Topic No. 2).
5. On July 1, as part of the Warming/Cooling Turn No. 6A activities, the
spacecraft under stored sequence control was commanded back to a 5 degree
off-sun attitude after remaining at the warming attitude for approximately 47
hours. After the sun acquisition, sun gate data was collected to determine if
an antenna rib is still obscuring the sun gate signal. Data analysis indicates
that the sun gate is still obscured, confirming no rib release (see Special
Topic No. 2).
6. On July 2, as part of the Warming/Cooling Turn No. 6A activities, real-time
commands were sent to checkout the Star Scanner (SS). This activity is
performed after each HGA thermal turn as a precaution to protect the star
scanner from "seeing" bright particles which could have been released if the
HGA ribs released (see Special Topic No. 2).
7. On July 2, as part of the Warming/Cooling Turn No. 6A activities, real-time
commands were sent to open the Star Scanner (SS) shutter and to reacquire
celestial reference. Additionally, the AACS gyro-based wobble data was
collected. The wobble test was performed with the spacecraft in the dual-spin
mode. Data analysis is in progress (see Special Topic No. 2).
8. On July 2, as part of the Warming/Cooling Turn No. 6A activities, real-time
commands were sent to switch from 40 bps coded telemetry to 10 bps coded
telemetry. Additionally, the pre-cool portion of the sequence started on
July 2 and will be completed on July 6. During this pre-cool phase the S-band
TWTA (Traveling Wave Tube Amplifier) is set to the low power mode and it is
expected that telemetry data will be consistently processed at 10 bps (see
Special Topic No. 2).
9. The AC/DC bus imbalance measurements exhibited some change. The DC
measurement increased 7 DN and reads 9.1 volts. The AC measurement increased
1 DN and reads 3.3 volts.
10. The Spacecraft status as of July 2, 1992, is as follows:
a) System Power Margin - 36 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.14 rpm/Star Scanner
d) Spacecraft Attitude is approximately 5 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-10 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EUV, DDS, MAG, UVS, EPD, HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 192 hours
Time To Initiation - 189 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Dual Drive Actuator (DDA) pulse/Low Gain Antenna 2 (LGA-2) stow
mini-sequence memory load was approved for generation by the Project on
June 30, 1992. This mini-sequence covers spacecraft activities from
July 21, 1992 to July 25, 1992.
TRAJECTORY
As of noon Thursday, July 2, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 154,658,000 miles (1.66 AU)
Distance from Sun 176,047,000 miles (1.90 AU)
Heliocentric Speed 43,500 miles per hour
Distance from Jupiter 678,749,000 miles
Round Trip Light Time 27 minutes, 50 seconds
SPECIAL TOPIC
1. As of July 2, 1992, a total of 7995 real-time commands have been transmitted
to Galileo since Launch. Of these, 3126 were pre-planned in the sequence
design and 4869 were not. In the past week, 34 real time commands were
transmitted and all were pre-planned in the sequence design. In addition, 4534
mini-sequence commands have been transmitted since March 1991; 2283 were
pre-planned and 2251 were not. In the past week, no mini-sequence commands were
transmitted. Major command activities this week included commands to reset the
command loss timer, update the System Fault Protection (SFP), checkout and
open the star scanner shutter, reacquire celestial reference, and switch to
10 bps coded telemetry.
2. The HGA Warming/Cooling Turn 6A activities are scheduled from June 29 to
July 10. The warming turn was performed on June 29 and the spacecraft
remained at the warming attitude for approximately 47 hours. The spacecraft
return from the warming attitude occurred on July 1 and sun gate data
collection began. A star scanner checkout, along with collection of wobble ID
data is occurring on July 2. The spacecraft bus cool down period started on
July 2 and will complete on July 6. The cooling turn will be performed on
July 6 and the spacecraft will remain at the cooling attitude for
approximately 44 hours. The spacecraft return from the cooling attitude will
occur on July 8. The star scanner checkout, along with collection of sun gate
and wobble ID data is scheduled during the July 8-10 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1376
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 07/06/92
Date: 7 Jul 92 04:36:17 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 6, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 10 bps.
Over the weekend, no spacecraft activity or tracking was scheduled. The
pre-cool portion of Cooling Turn No. 6A continued throughout the weekend.
Today, July 6, 1992, the turn to the cooling attitude is scheduled to
begin at approximately 11:14 PDT. The spacecraft will remain at the cooling
attitude for approximately 44 hours. Tracking is scheduled over DSS-43
(Canberra 70 meter antenna).
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1392
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/07/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 8 Jul 1992 01:37:40 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 7, 1992
The Galileo Spacecraft is at the cooling attitude and appears to be
operating normally in the all-spin mode and transmitting coded telemetry at
10 bps (bits/second).
Yesterday, the turn to the cooling attitude began at approximately
11:14 PDT and was completed as scheduled. Loss of downlink carrier occurred
close to the predicted time at approximately 13:18 PDT during the maneuver to
the cooling attitude. The spacecraft will remain at the cooling attitude for
approximately 44 hours. Tracking was performed over DSS-43 (Canberra 70 meter
antenna).
Today, July 7, 1992, no spacecraft activity is scheduled. Partial
tracking is scheduled over DSS-43. Coverage is required to provide an
indication of a downlink signal in case of a spacecraft safing action; due
to geometric conditions, there is no downlink signal while at the cooling
attitude.
Tomorrow, the spacecraft, under stored sequence control, will return from
the cooling attitude to a 5 degree off-sun attitude; the sun acquisition will
complete at approximately 12:05 PDT. Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1404
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/08/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 9 Jul 1992 01:53:50 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 8, 1992
The Galileo Spacecraft is at the cooling attitude and appears to be
operating normally in the all-spin mode and transmitting coded telemetry at
10 bps.
Yesterday, no spacecraft activity was scheduled. A short tracking pass
was performed over DSS-43 (Canberra 70 meter antenna). Coverage was required
to provide an indication of a downlink signal in case of a spacecraft safing
action; due to geometric conditions, there is no downlink signal while at the
cooling attitude.
Today, July 8, 1992, the spacecraft, under stored sequence control, will
return from the cooling attitude to a 5 degree off-sun attitude; the sun
acquisition will complete at approximately 12:05 PDT. Additionally, real-time
commands are scheduled to switch from 10 bps coded telemetry to 40 bps coded
telemetry, Tracking is scheduled over DSS-43.
Tomorrow, real-time commands are scheduled to checkout the Star Scanner
(SS) and reacquire celestial reference along with collecting wobble ID data.
Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1414
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 07/09/92
Date: 10 Jul 92 01:46:03 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 9, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the spacecraft, under stored sequence control, returned from
the cooling attitude to a 5 degree off-sun attitude, as planned. Initial sun
gate data analysis indicates the sun gate is still obscured, confirming no ribs
released. Additionally, real-time commands were sent to switch from 10 bps
coded telemetry to 40 bps coded telemetry. Tracking was performed over DSS-43
(Canberra 70 meter antenna).
Today, July 9, 1992, real-time commands are scheduled to checkout the
Star Scanner (SS) and reacquire celestial reference along with collecting
wobble ID data. Tracking is scheduled over DSS-43.
Tomorrow, real-time commands are scheduled to update the system fault
protection parameters. Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
|
| 560.665 | Updates - July 10-17 | VERGA::KLAES | Slaves to the Metal Hordes | Fri Jul 17 1992 18:34 | 437 |
| Article: 1424
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/10/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 11 Jul 1992 01:16:39 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 3 - 9, 1992
SPACECRAFT
1. On July 6, as part of the Warming/Cooling Turn No. 6A activities, the
pre-cool portion of Cooling Turn No. 6A was completed. The spacecraft bus
cool down behaved similar to Cooling Turn No. 6. The cooling turn to a 165
degree off-sun attitude commenced at approximately 18:14 UTC. Downlink
telemetry and carrier loss of lock occurred at approximately 20:04 UTC and
20:18 UTC, respectively. The turn was scheduled to complete at 20:51 UTC
(see Special Topic No. 2).
2. On July 8, after approximately 44 hours at the cooling attitude, the
spacecraft under stored sequence control was commanded back to a 5 degree
off-sun attitude. The downlink carrier was acquired at 17:38 UTC and
telemetry was received at 17:52 UTC. The spacecraft return to a 5 degree
off-sun attitude completed at approximately 19:05 UTC. After the sun
acquisition, sun gate data was collected to determine if an antenna rib is
still obscuring the sun gate signal. Data analysis indicates that the sun
gate is still obscured, indicating no ribs released (see Special Topic No. 2).
3. On July 8, as part of the Warming/Cooling Turn No. 6A activities,
real-time commands were sent to switch from 10 bps coded telemetry to 40 bps
coded telemetry. This command was sent after the S-band TWTA (Traveling
Wave Tube Amplifier) was set to the high power mode via the stored sequence
(see Special Topic No. 2).
4. On July 9, as part of the Warming/Cooling Turn No. 6A activities,
real-time commands were sent to checkout the Star Scanner (SS). This
activity is performed after each HGA (High Gain Antenna) thermal turn as a
precaution to protect the star scanner from "seeing" bright particles which
could have been released if the HGA ribs released (see Special Topic No. 2).
5. On July 9, as part of the Warming/Cooling Turn No. 6A activities,
real-time commands were sent to open the Star Scanner (SS) shutter and to
reacquire celestial reference. Additionally, the AACS (Attitude and
Articulation Control Subsystem) gyro-based wobble data was collected. The
wobble test was performed with the spacecraft in the dual-spin mode. Data
analysis is in progress (see Special Topic No. 2).
6. During the week, the DC bus imbalance reading has continued to change
significantly. The DC measurement has ranged from 80DN (9.1 volts) to
138 DN (16.2 volts) and now reads 135DN (15.8 volts). This measurement
variation is consistent with the model developed by the AC/DC special
anomaly team. The AC measurement has remained relatively unchanged and
reads 14DN (3.3 volts).
7. The Spacecraft status as of July 9, 1992, is as follows:
a) System Power Margin - 48 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.14 rpm/Star Scanner
d) Spacecraft Attitude is approximately 5 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- SSI, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 257 hours
GDS (Ground Data Systems):
1. The DSN (Deep Space Network) reports that the DSS-14 (Goldstone 70
meter) antenna subreflector support mechanism partially failed during the
first June 28 earthquake and allowed the subreflector to fall into the quad
legs. Damage was sustained to the subreflector as well as to the
subreflector control mechanism. Repair is currently in progress. Anticipated
return to service is July 22, which is before the next scheduled Galileo track
using DSS-14.
TRAJECTORY
As of noon Thursday, July 9, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 144,909,000 miles (1.56 AU)
Distance from Sun 173,125,000 miles (1.86 AU)
Heliocentric Speed 44,400 miles per hour
Distance from Jupiter 676,362,000 miles
Round Trip Light Time 26 minutes, 6 seconds
SPECIAL TOPIC
1. As of July 9, 1992, a total of 8026 real-time commands have been
transmitted to Galileo since Launch. Of these, 3157 were pre-planned in the
sequence design and 4869 were not. In the past week, 31 real time commands
were transmitted and all were pre-planned in the sequence design. In addition,
4534 mini-sequence commands have been transmitted since March 1991; 2283 were
pre-planned and 2251 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
switch to 40 bps coded telemetry, checkout and open the star scanner shutter,
and reacquire celestial reference.
2. The HGA Warming/Cooling Turn 6A activities were scheduled from June 29 to
July 10. The warming turn was performed on June 29 and the spacecraft
remained at the warming attitude for approximately 47 hours. The spacecraft
return from the warming attitude occurred on July 1 and sun gate data
collection began. A star scanner checkout, along with collection of wobble ID
data was performed on July 2. The spacecraft bus cool down period started on
July 2 and completed on July 6. The cooling turn was performed on July 6 and
the spacecraft remained at the cooling attitude for approximately 44 hours.
The spacecraft return from the cooling attitude occurred on July 8. The star
scanner checkout, along with collection of sun gate and wobble ID data is
scheduled during the July 8-10 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1425
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 07/10/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 11 Jul 1992 04:11:14 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 10, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, real-time commands were sent to checkout the Star Scanner
(SS) and reacquire celestial reference along with collecting wobble ID data,
as planned. Tracking was performed over DSS-43 (Canberra 70 meter antenna).
Today, July 10, 1992, real-time commands are scheduled to update the
system fault protection parameters. Tracking is scheduled over DSS-43.
Over the weekend, no spacecraft activity or tracking is scheduled.
Tracking will continue on Monday over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1451
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 07/13/92
Date: 14 Jul 92 05:11:36 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 13, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40bps (bits/second).
Over the weekend, no spacecraft activity or tracking was scheduled.
Today, July 13, 1992, no spacecraft is scheduled. Tracking is scheduled
over DSS-43 (Canberra 70 meter antenna).
Tomorrow, telecommunication (telecom) tests are scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1461
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/14/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 15 Jul 1992 04:48:46 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 14, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-43 (Canberra 70 meter antenna).
Today, July 14, 1992, spacecraft telecommunication (telecom) tests are
scheduled over DSS-43.
Tomorrow, the routine RPM (Retro-Propulsion Module) 10-Newton thruster
"flushing" maintenance activity, Energetic Particle Detector (EPD) motor
maintenance exercise, routine cruise science Memory Readouts (MROs), and an
Ultra-Stable Oscillator (USO) test are scheduled. Tracking is scheduled over
DSS-43 and DSS-63 (Madrid 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1464
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/15/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 16 Jul 1992 02:47:48 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 15, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, spacecraft telecommunication (telecom) tests were performed,
as planned, over DSS-43 (Canberra 70 meter antenna).
Today, July 15, 1992, the routine RPM (Retro-Propulsion Module) 10-Newton
thruster "flushing" maintenance activity, Energetic Particle Detector (EPD)
motor maintenance exercise, routine cruise science Memory Readouts (MROs), and
an Ultra-Stable Oscillator (USO) test are scheduled. Additionally, real-time
commands are scheduled to update the System Fault Protection (SFP) in
preparation for the Low Gain Antenna-2 (LGA-2) stow activity. Tracking is
scheduled over DSS-43 and DSS-63 (Madrid 70 meter antenna).
Tomorrow, a command threshold test and Radio Frequency Subsystem
Tracking Loop Capacitor (RFSTLC) test are scheduled. Tracking is scheduled
over DSS-63 and DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | In 1991 there were 16 names
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | listed on the FBI's ten
|_____|/ |_|/ |_____|/ | most wanted list.
Article: 1477
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/16/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 17 Jul 1992 04:51:09 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 16, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps (bits/second).
Yesterday, the routine RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity, Energetic Particle Detector (EPD) motor
maintenance exercise, routine cruise science Memory Readouts (MROs), and an
Ultra-Stable Oscillator (USO) test were performed, as planned. Planned
real-time commanding was not succesful due to ground station reconfiguration
problems. Alternative plans are being developed. Tracking was performed over
DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, July 16, 1992, a command threshold test and Radio Frequency
Subsystem Tracking Loop Capacitor (RFSTLC) test are scheduled. Tracking is
scheduled over DSS-63 and DSS-43.
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1481
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/17/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 18 Jul 1992 01:05:27 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 10 - 16, 1992
SPACECRAFT
1. On July 10, realtime commands were sent to change the System Fault
Protection (SFP) AACS-INIT (Attitude and Articulation Control Subsystem)
pointing slot from the sun to the Earth. These commands reconfigured the
value to the background state assumed by the EE-6 (Earth-Earth 6) sequence
memory load.
2. On July 13, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.
3. On July 14, a Command Detector Unit Signal-to-Noise Ratio (CDUSNR) test
along with a Radio Frequency Subsystem Automatic Gain Control (RFSAGC) test
were performed using LGA-1 (Low Gain Antenna #1) over DSS-43 (Canberra 70
meter antenna). Quick look analysis indicates the test went well. Detailed
analysis is in progress.
4. On July 15, the periodic RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed. All 12 thrusters were flushed
and their performance was as expected.
5. On July 15, the Energetic Particle Detector (EPD) motor maintenance
exercise was performed which stepped the motor through its eight operating
positions and then returned it to the normal position (No. 4). The motor
maintenance exercise was successfully verified by Memory Readout (MRO)
commands.
6. On July 15, realtime commands were sent to change the System Fault
Protection (SFP) to turn off the LGA-2 motor if the sequence memory load is
terminated. This change prevents a continuous undervoltage situation in
the low probability scenario of a relay failure causing a DC bus short
circuit while retracting the LGA-2 antenna. The commands were transmitted
but not successfully received due to a ground station problem. Specifically,
the wrong standards and limit tables were being used in the command system at
Station 43 (Canberra). Command retransmission is being planned.
7. On July 16, routine Extreme Ultraviolet Spectrometer (EUV) Memory
Readouts (MROs) were performed. The MROs were received without incident.
8. On July 16, cruise science Memory Readouts (MROs) were performed for the
Dust Detector (DDS) and Magnetometer (MAG) instruments. Preliminary analysis
indicates the data was received properly.
9. On July 16, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and collect gravitational red shift experiment
data; long term trend analysis is continuing.
10. On July 16, a command threshold test was performed. Initial results,
similar to the test run on May 14, indicates the command threshold to be
approximately -140 to -141 dbm which is its nominal value.
11. On July 16, a Radio Frequency Subsystem Tracking Loop Capacitor (RFSTLC)
test was performed over DSS-43. Preliminary analysis indicates the capacitors
continue to operate normally.
12. On July 16, telemetry map changes were performed to replace the Command
Detector Unit Signal-to-Noise (CDUSNR) telemetry readings to the AC/DC bus
imbalance telemetry readings at the completion of the scheduled
telecommunication tests.
13. During the week, the DC bus imbalance reading has continued to change
significantly. The DC measurement has ranged from 97DN (11.2 volts) to 151DN
(17.8 volts) and now reads 150DN (17.7 volts). This measurement variation is
consistent with the model developed by the AC/DC special anomaly team. The
AC measurement has decreased 1DN and reads 3.1 volts.
14. The Spacecraft status as of July 16, 1992, is as follows:
a) System Power Margin - 42 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 31 degrees off
Earth (lagging) and 2 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 185 hours
GDS (Ground Data Systems):
1. The July System Engineers Monthly Report (SEMR) review was conducted
Thursday, July 16. A review of current Project and Institutional (MOSO & DSN)
system status was conducted. Pre-Earth 2 delivery schedules, past months
accomplishments and potential problem areas were discussed. No significant
problems or errors were reported.
2. An end-to-end GDS data flow test was successfully conducted this past week
to demonstrate the ground capability to process and display 40 bps AACS Flood
Mode telemetry data. First use of this telemetry format in flight is
scheduled for 24 July.
TRAJECTORY
As of noon Thursday, July 16, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 135,214,000 miles (1.46 AU)
Distance from Sun 170,085,000 miles (1.83 AU)
Heliocentric Speed 45,300 miles per hour
Distance from Jupiter 673,747,000 miles
Round Trip Light Time 24 minutes, 22 seconds
SPECIAL TOPIC
1. As of July 16, 1992, a total of 8028 real-time commands have been
transmitted to Galileo since Launch. Of these, 3159 were pre-planned in
the sequence design and 4869 were not. In the past week, 2 real time commands
were transmitted and all were pre-planned in the sequence design. In addition,
4534 mini-sequence commands have been transmitted since March 1991; 2283 were
pre-planned and 2251 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
update the System Fault Protection (SFP) and to reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
|
| 560.666 | Updates - July 17-23 | VERGA::KLAES | Slaves to the Metal Hordes | Fri Jul 24 1992 22:06 | 388 |
| Article: 1482
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 07/17/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 18 Jul 1992 02:48:57 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 17, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, a command threshold test and Radio Frequency Subsystem Tracking
Loop Capacitor (RFSTLC) test were performed as scheduled. Tracking was
scheduled over DSS-63 (Madrid 70 meter antenna) and DSS-43 (Canberra 70 meter
antenna).
Today, July 17, 1992, real-time commands are scheduled to verify the
commandability of the spacecraft following the Command Processor Assembly (CPA)
configuration problem. Tracking is scheduled over DSS-43.
Over the weekend, real-time commanding is planned to update the System
Fault Protection (SFP) on Sunday. Tracking is scheduled over DSS-43 on Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1498
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/20/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 21 Jul 1992 02:47:09 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 20, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Over the weekend, real-time commands were sent to update the System Fault
Protection (SFP) on Sunday, as planned. Tracking was performed over DSS-43
(Canberra 70 meter antenna) on Sunday.
Today, July 20, 1992, the uplink of the Dual Drive Actuator (DDA)
pulse/Low Gain Antenna-2 (LGA-2) stow mini-sequence is scheduled along with
real-time commands to update telemetry map variable packets. Tracking is
scheduled over DSS-43.
Tomorrow, the turn to the warming attitude in preparation for the Dual
Drive Actuator (DDA) pulse is scheduled to begin at approximately 10:57PDT.
The first of the two Dual Drive Actuator pulses is scheduled at 12:46 PDT for
approximately a 2 second duration. Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1509
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/21/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 22 Jul 1992 02:00:15 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 21, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40bps.
Yesterday, the uplink of the Dual Drive Actuator (DDA) pulse/Low Gain
Antenna-2 (LGA-2) stow mini-sequence along with real-time commands to update
telemetry map variable packets were performed, as planned. Tracking was
performed over DSS-43 (Canberra 70 meter antenna).
Today, July 21, 1992, the turn to the warming attitude in preparation for
the Dual Drive Actuator (DDA) pulse is scheduled to begin at approximately
10:57 PDT. The first of the two Dual Drive Actuator pulse turn ons is
scheduled at 12:46 PDT for approximately a 2-second duration. Tracking is
scheduled over DSS-43. Tomorrow, the second Dual Drive Actuator pulse is
scheduled at 11:01 PDT for approximately a 2-second duration. Additionally,
the turn back from the warming attitude is scheduled to begin at approximately
11:07 PDT. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna) and
DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1517
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/22/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 23 Jul 1992 00:21:34 GMT
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
July 22, 1992
The Galileo spacecraft is more than 204 million kilometers
(about 127 million miles) from Earth, and some 269 million
kilometers from the Sun; its speed in orbit is 20,651 meters per
second or 46,194 miles per hour. The spacecraft has flown about
2.13 billion kilometers (1.32 billion miles) since launch.
This week Galileo is conducting exploratory activities with
the high-gain antenna deployment motors and retracting its rear-
view low-gain antenna. On Monday, the flight team sent the mini-
sequence for these operations to the spacecraft.
Tuesday, the spacecraft turned to a warming attitude (31
degrees off the Sun) and turned on the antenna-deploy motors for
less than 2 seconds, and today, Wednesday, the motors are being
turned on for another 2 seconds after 24 hours of warming. (The
first deploy-motor pulse was done April 29, when the antenna
tower region was somewhat cooler).
Thursday, July 23, the spacecraft's second low-gain antenna,
which pivots down on a long mast from one of the RTG booms, will
be driven back up to its stowed position. This action will exert
small forces on the spacecraft, which will be measured using the
spacecraft gyros.
Engineering telemetry for these events will be captured on
the spacecraft tape recorder and played back each day. The
engineers believe these activities may provide a better under-
standing of the antenna situation to support future action.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1521
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 07/22/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 23 Jul 1992 04:37:28 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 22, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the turn to the warming attitude in preparation for the Dual
Drive Actuator (DDA) pulse began at approximately 10:57 PDT, as planned. The
first of the two Dual Drive Actuator pulse turn ons occurred at 12:46 PDT for
approximately a 2-second duration, as planned. Data was collected and is
being evaluated. Tracking was performed over DSS-43 (Canberra 70 meter
antenna).
Today, July 22, 1992, the second Dual Drive Actuator pulse is scheduled
at 11:01 PDT for approximately a 2-second duration. Additionally, the turn
back from the warming attitude is scheduled to begin at approximately
11:07 PDT. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna) and
DSS-43.
Tomorrow, the Low Gain Antenna-2 (LGA-2) motors are scheduled on at
12:46 PDT for a duration of approximately 16 seconds to stow the LGA-2.
Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43, and
DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1527
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/23/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 24 Jul 1992 00:36:31 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 23, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the second Dual Drive Actuator pulse began at 11:01 PDT for
approximately a 2-second duration. Additionally, the turn back from the
warming attitude began at approximately 11:07 PDT, as planned. Data was
collected and is being evaluated. Tracking was performed over DSS-63 (Madrid
70 meter antenna) and DSS-43 (Canberra 70 meter antenna).
Today, July 23, 1992, the Low Gain Antenna-2 (LGA-2) motors are scheduled
on at 12:46 PDT for a duration of approximately 16 seconds to stow the LGA-2.
Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43, and
DSS-63.
Tomorrow, real-time commands are scheduled to checkout the Star Scanner
(SS), acquire celestial reference and update the system fault protection.
Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1539
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/23/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 25 Jul 1992 02:43:50 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 17 - 23, 1992
SPACECRAFT
1. On July 17, realtime commands were sent to verify the commandability of
the spacecraft following the Command Processor Assembly (CPA) configuration
problem on Wednesday, July 15. A single frame command followed by a
multi-frame command were sent and successfully received by the spacecraft.
2. On July 19, real-time commands, previously attempted on July 15 and
unsuccessfully received by the spacecraft, were sent to change the System Fault
Protection (SFP) to turn off the LGA-2 (Low Gain Antenna #2) motor if the
sequence memory load is terminated. This change prevents a continuous
undervoltage situation in the low probability scenario of a relay failure
causing a DC bus short circuit while retracting the LGA-2 antenna. The
commands were successfully received by the spacecraft (see Special Topic
No. 2).
3. On July 20, the Dual Drive Actuator (DDA) pulse/Low Gain Antenna 2 (LGA-2)
stow sequence memory load was sent to the spacecraft. The sequence was loaded
on the spacecraft without incident (see Special Topic No. 2).
4. On July 20, realtime commands were sent to insert sun gate data into
telemetry Map 1 variable Packet No. 9. This change will allow wobble data and
sun gate data to be obtained simultaneously during the DDA pulse/LGA-2 stow
mini-sequence (see Special Topic No. 2).
5. On July 21, realtime commands were sent to change the System Fault
Protection (SFP) AACS-INIT (Attitude and Articulation Control Subsystem)
pointing slot from the Earth to the Sun prior to the DDA pulse/LGA-2 stow
activities. This change will allow the spacecraft to return to a sun-pointed
attitude if an AACS Power on Reset (POR) occurs during DDA pulse/LGA-2 stow
activities (see Special Topic No. 2).
6. On July 21, the DDA pulse/LGA-2 stow sequence memory load went active.
The warming turn to a 31-degree off-sun attitude commenced at approximately
1757 UTC and completed at 1804 UTC. The first of two motor turn on pulses
occurred at 1946 UTC for approximately 2 seconds, as planned. The DDA motor
temperature was approximately minus 25 degrees C at turn on. Initial results
indicate the motor stalled at 100 milliseconds with inconclusive evidence of
ballscrew rotation (see Special Topic No. 2).
7. On July 22, after approximately 24 hours at the warming attitude, the
second motor turn on pulse occurred at 1801 UTC for approximately 2 seconds,
as planned. The DDA motor temperature was approximately minus 6 degrees C at
turn on. Initial results are that the motor stalled at 126 milliseconds
indicating some ballscrew rotation occurred. Additionally, the spacecraft
under stored sequence control, was commanded back to a 5 degree off-sun
attitude at approximately 18:07 UTC. After the sun acquisition, sun gate data
was collected to determine if an antenna rib is still obscuring the sun gate
signal. Data analysis indicates that the sun gate is still obscured,
indicating no ribs released (see Special Topic No. 2).
8. On July 23, the Low Gain Antenna (LGA-2) motors were turned on at
approximately 1946 UTC for a duration of 16 seconds to stow the LGA-2 antenna
and collect spacecraft dynamics data from the activity. Additionally, realtime
commands were sent to perform an open loop wobble compensation. Data analysis
is in progress.
9. During the week, the DC bus imbalance reading has continued to change
significantly. The DC measurement has ranged from 92DN (10.6 volts) to 151DN
(17.8 volts) and now reads 108DN (12.5 volts). This measurement variation is
consistent with the model developed by the AC/DC special anomaly team. The AC
measurement has remained relatively unchanged and reads 3.1 volts.
10. The Spacecraft status as of July 23, 1992, is as follows:
a) System Power Margin - 51 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 5 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 263 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Dual Drive Actuator (DDA) pulse/LGA-2 stow mini-sequence memory load
was approved for transmission by the Project on July 17, 1992. This
mini-sequence covers spacecraft activities from July 21, 1992 to July 24, 1992.
2. The EE-7 (Earth-Earth 7) final sequence and command generation package was
approved by the Project on July 23, 1992. This sequence covers spacecraft
activities from August 10, 1992 to November 23, 1992.
TRAJECTORY
As of noon Thursday, July 23, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 125,608,000 miles (1.35 AU)
Distance from Sun 166,926,000 miles (1.80 AU)
Heliocentric Speed 46,300 miles per hour
Distance from Jupiter 670,891,000 miles
Round Trip Light Time 22 minutes, 38 seconds
SPECIAL TOPIC
1. As of July 23, 1992, a total of 8062 real-time commands have been
transmitted to Galileo since Launch. Of these, 3190 were pre-planned in the
sequence design and 4872 were not. In the past week, 28 real time commands
were transmitted; 25 were pre-planned in the sequence design and 3 were not.
In addition, 5453 mini-sequence commands have been transmitted since March
1991; 3201 were pre-planned and 2252 were not. In the past week, 414
mini-sequence commands were transmitted. Major command activities this week
included commands to verify the commandability of the spacecraft, update the
System Fault Protection (SFP), uplink the DDA pulse/LGA-2 stow sequence memory
load, update the telemetry map variable packets, and perform wobble
compensation.
2. The High Gain Antenna (HGA) DDA pulse/LGA-2 stow activities are scheduled
from July 21 to July 24, 1992. The warming turn to a 31 degree off-sun
attitude along with the first DDA two second motor turn on was performed on
July 21. The spacecraft remained at the warming attitude for approximately
24 hours. The second DDA motor turn on was performed on July 22 just prior
to the spacecraft turning back to a 5 degree off-sun attitude. Sun gate data
was collected after the sun acquisition completed. The LGA-2 motors were
turned on for 16 seconds on July 23 and the LGA-2 antenna was successfully
stowed. The star scanner checkout, along with collection of sun gate and
wobble data is scheduled during the July 23-24 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
|
| 560.667 | Updates - July 24-31 | VERGA::KLAES | Slaves to the Metal Hordes | Fri Jul 31 1992 21:15 | 245 |
| Article: 1542
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 07/24/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 25 Jul 1992 05:33:19 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 24, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, the Low Gain Antenna-2 (LGA-2) motors were turned on
at 12:46 PDT for a duration of approximately 16 seconds to stow the
LGA-2, as planned. Tracking was performed over DSS-14, DSS-43, and
DSS-63 (all three of the 70 meter antennas in the Deep Space Network
at Goldstone, Canberra and Madrid, respectively).
Today, July 24, 1992, real-time commands are scheduled to checkout the
Star Scanner (SS), reacquire celestial reference, collect precise wobble
estimates, and update the system fault protection. Tracking is scheduled
over DSS-43.
Over the weekend, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1555
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 07/27/92
Date: 28 Jul 92 05:17:32 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
GALILEO STATUS REPORT
July 27, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Over the weekend, no spacecraft activity was scheduled. Tracking was
performed over DSS-43 (Canberra 70 meter antenna).
Today, July 27, 1992, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1562
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 07/29/92
Date: 30 Jul 92 01:05:40 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 29, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps. The period from July 20 thru July 31
was reserved in the sequence design as a High Gain Antenna (HGA) activity
window with no background sequence activities scheduled. HGA activities were
planned and executed on the spacecraft thru July 25. No further HGA
activities have been scheduled thru the remainder of the window.
Yesterday, no spacecraft activity was scheduled. Tracking was performed
over DSS-43 (Canberra 70 meter antenna).
Today, July 29, 1992, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
Tomorrow, no spacecraft activity is scheduled. Tracking will continue
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1585
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 07/30/92
Date: 31 Jul 92 05:15:55 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 30, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps. The period from July 20 thru July 31
was reserved in the sequence design as a High Gain Antenna (HGA) activity
window with no background sequence activities scheduled. HGA activities were
planned and executed on the spacecraft thru July 25. No further HGA
activities have been scheduled thru the remainder of the window.
Yesterday, no spacecraft activity was scheduled. Tracking was performed
over DSS-43 (Canberra 70 meter antenna).
Today, July 30, 1992, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
Tomorrow, the uplink of the SITURN in preparation for Trajectory
Correction Maneuver-14 (TCM-14) is scheduled along with power reconfiguration
and science Memory Readout (MRO) commands. Tracking will continue over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1595
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 07/31/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 1 Aug 1992 00:34:23 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 24 - 30, 1992
SPACECRAFT
1. On July 24, as part of the DDA (Dual Device Actuator) pulse/LGA-2 (Low
Gain Antenna #2) stow activity, real-time commands were sent to checkout the
star scanner. This activity was performed as a precaution to protect the star
scanner from "seeing" bright particles which could release if an HGA (High
Gain Antenna) rib released. Additionally, real-time commands were sent to
open the Star Scanner (SS) shutter and to reacquire celestial reference.
Scan Type 6 was selected which allowed the collection of precise wobble data.
Analysis indicates the wobble estimate to be approximate .7 milliradians
following the open loop wobble compensation on July 23. Also, real-time
commands were sent to reconfigure the System Fault Protection (SFP) AACS-INIT
(Attitude and Articulation Control Subsystem) pointing slot from the Sun to
the Earth after the DDA pulse/LGA-2 stow activities. This change will allow
the spacecraft to lock up on the star set in the Earth slot if an AACS Power
on Reset (POR) occurs.
2. On July 27, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
3. During the week, the DC bus imbalance reading has continued to change
significantly. The DC measurement has ranged from 105DN (12.2 volts) to
148DN (17.4 volts) and now reads 122DN (14.2 volts). This measurement
variation is consistent with the model developed by the AC/DC special anomaly
team. The AC measurement has remained relatively unchanged and reads
3.1 volts.
4. The Spacecraft status as of July 30, 1992, is as follows:
a) System Power Margin - 51 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.16 rpm/Star Scanner
d) Spacecraft Attitude is approximately 5 degrees off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 184 hours
GDS (Ground Data Systems):
1. The DSN (Deep Space Network) placed the new Telemetry Processor Assembly
(TPA) software version OP-D 4.01 into SOAK test at all complexes on 28 July.
The project participated in a successful Multimission Verification Test (MVT)
for this software on May 27.
TRAJECTORY
As of noon Thursday, July 30, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 116,127,000 miles (1.25 AU)
Distance from Sun 163,651,000 miles (1.76 AU)
Heliocentric Speed 47,400 miles per hour
Distance from Jupiter 667,782,000 miles
Round Trip Light Time 20 minutes, 56 seconds
SPECIAL TOPIC
1. As of July 30, 1992, a total of 8094 real-time commands have been
transmitted to Galileo since Launch. Of these, 3222 were pre-planned in the
sequence design and 4872 were not. In the past week, 32 real time commands
were transmitted; all were pre-planned in the sequence design. In addition,
5453 mini-sequence commands have been transmitted since March 1991; 3201 were
pre-planned and 2252 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
checkout the star scanner, open the star scanner shutter and reacquire
celestial reference, select scan Type 6, reconfigure the system fault
protection, and reset the command loss timer.
2. The High Gain Antenna (HGA) DDA pulse/LGA-2 stow activities were scheduled
from July 21 to July 24, 1992. The warming turn to a 31 degree off-sun
attitude along with the first DDA two second motor turn on was performed on
July 21. The spacecraft remained at the warming attitude for approximately
24 hours. The second DDA motor turn on was performed on July 22 just prior to
the spacecraft turning back to a 5 degree off-sun attitude. Sun gate data was
collected after the sun acquisition completed. The LGA-2 motors were turned
on for 16 seconds on July 23 and the LGA-2 antenna was successfully stowed.
The star scanner checkout, along with collection of sun gate and wobble data
was completed during the July 23-24 time period.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
|
| 560.668 | Updates - July 31 to August 6 | VERGA::KLAES | Slaves to the Metal Hordes | Fri Aug 07 1992 20:27 | 192 |
| Article: 1596
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 07/31/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 1 Aug 1992 02:19:46 GMT
GALILEO STATUS REPORT
July 31, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
transmitting coded telemetry at 40 bps.
Yesterday, no spacecraft activity was scheduled. Tracking was performed
over DSS-43 (Canberra 70 meter antenna).
Today, July 31, 1992, the uplink of the SITURN in preparation for
Trajectory Correction Maneuver-14 (TCM-14) is scheduled along with power
reconfiguration and science Memory Readout (MRO) commands. Tracking is
scheduled over DSS-43.
Over the weekend, an Ultra Stable Oscillator (USO) test, science Memory
Readouts (MROs) and a navigation cycle are scheduled. Tracking is scheduled
over DSS-63, DSS-43, and DSS-14 (70 meter antennas in Madrid, Canberra and
Goldstone respectively). The pre-TCM-14 SITURN to a 2-degree off-sun attitude
is scheduled to execute on Monday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never
|_____|/ |_|/ |_____|/ | happen.
Article: 1618
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 08/03/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 4 Aug 1992 03:35:26 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 3, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and is
transmitting coded telemetry data at 40 bps.
Today, the spacecraft is scheduled to perform another routine RPM
(Retro-Propulsion Module) 10-Newton thruster flushing activity. All 12
thrusters will be exercised during the activity.
Later today, at about 1840 PDT, a SITURN (~3.9 degrees) will be performed
to achieve the proper attitude for TCM-14 (Trajectory Correction Maneuver #14).
Tomorrow, the first of the four portion TCM-14 maneuver will be performed.
This maneuver portion will begin at about 0700 PDT; the maneuver is expected
to impart a lateral delta velocity of 6.2 m/sec. of the total TCM-14 planned
21 m/sec.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | You can't hide brocolli in
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a glass of milk -
|_____|/ |_|/ |_____|/ | anonymous 7-year old.
Article: 1643
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 08/05/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 6 Aug 1992 00:10:02 GMT
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
August 5, 1992
The Galileo spacecraft is 174 million kilometers (108 million
miles) from Earth, and about 259 million kilometers from the Sun. Its
speed in orbit is 21,630 meters per second, more than 48,000 mph. It
is operating normally and transmitting coded telemetry at 40 bits per
second.
This week the spacecraft is using the onboard propulsion
subsystem to change its trajectory for the fourteenth time since
launch. It is pulsing its tiny thrusters more than 5400 times over a
four-day period. On Monday, August 3, a routine propulsion-system
maintenance activity "flushed" the thrusters. The same day, the
thrusters were fired to orient the spacecraft for the maneuver.
Tuesday at about 7:00 a.m. PDT Galileo began the first portion of the
maneuver, to change its velocity by about 6.2 meters per second.
Similar maneuver portions are occurring today and Thursday, August 6.
On Friday at about 11:30 a.m. PDT the fourth portion will conclude;
Galileo's velocity will have changed by about 21 meters per second (47 mph).
The flight team designed this maneuver as the first in a planned
series to set up and refine the second Earth gravity assist on
December 8, 1992, taking into account the Asteroid Ida encounter, now
approved and scheduled for August 1993.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | You can't hide broccoli in
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a glass of milk -
|_____|/ |_|/ |_____|/ | anonymous 7-year old.
Article: 1655
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update #2 - 08/05/92
Date: 6 Aug 92 07:57:13 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 5, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry data at 40 bps.
Yesterday, the Galileo spacecraft completed the first portion of the
four portion TCM-14 (Trajectory Correction Maneuver #14) maneuver. The
sequence memory load for the second maneuver portion (TCM-14B) was
transmitted and received.
Today, TCM-14B began execution, as planned, about 0700 PDT. Similar to
the first portion, TCMB will use the L-thrusters to impart a delta velocity
of 6.2 m/sec. Later today, the sequence memory load for TCM-14C is scheduled
to be transmitted.
Tomorrow, the third portion of TCM-14 is scheduled to begin at 0700 PDT
and impart a delta velocity of 6.2 m/sec.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | You can't hide broccoli in
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a glass of milk -
|_____|/ |_|/ |_____|/ | anonymous 7-year old.
Article: 1663
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 08/06/92
Date: 7 Aug 92 08:25:52 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 6, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry data at 40 bps.
Yesterday, the Galileo spacecraft completed the second portion of the
four portion TCM-14 (Trajectory Correction Manuever #14) maneuver. The
sequence memory load for the third maneuver portion (TCM-14C) was transmitted
and received.
Today, TCM-14C began execution, as planned, about 0700 PDT. Similar to
the first and second portions; TCM-C will use the L-thrusters to impart a
delta velocity of 6.2 m/sec. Later today, the sequence memory load for TCM-14D
is scheduled to be transmitted.
Tomorrow, the final portion of TCM-14 is scheduled to begin at 0700 PDT
and impart a delta velocity of about 2.3 m/sec. The sequence memory load for
the EE-7 (Earth-Earth #7) sequence is scheduled for transmission to the
spacecraft after TCM14-D burn completion.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | You can't hide broccoli in
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a glass of milk -
|_____|/ |_|/ |_____|/ | anonymous 7-year old.
|
| 560.669 | Updates - August 7-14 | VERGA::KLAES | Slaves to the Metal Hordes | Fri Aug 14 1992 20:57 | 310 |
| Article: 1674
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 08/07/92
Date: 8 Aug 92 07:39:38 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 30 - August 6, 1992
SPACECRAFT
1. Commands were sent on July 31 to increase the spacecraft power margin to
warm the RPM (Retro_Propulsion Module) propellant tanks in preparation for
TCM-14 (Trajectory Correction Maneuver #14) on August 4-7.
2. Cruise Science Memory Readouts (MROs) were performed by the stored
sequence for the MAG (Magnetometer) and DDS (Dust Detector) instruments on
August 2 and for the EUV (Extreme Ultraviolet Spectrometer) instrument on
August 3. An additional real-time EUV MRO was performed on July 31, to
return recent data for comparison with earlier EUV data taken under similar
solar conditions.
3. Another RPM 10-Newton thruster maintenance activity was performed on
August 3. The activity "flushed" all 12 thrusters; spacecraft performance
throughout the activity was normal.
4. In preparation for the start of the TCM-14 maneuver, the spacecraft
performed a 4-degree SITURN on August 4 to the desired maneuver attitude.
5. TCM-14 maneuver sequence memory loads were sent to the spacecraft for
maneuver potions A, B, and C on August 4, 5, and 6, respectively. Each
maneuver portion, using the L-thrusters is designed to impart a delta velocity
of 6.2 m/sec. The last maneuver portion (D) is scheduled to be sent on
August 6 for execution on August 7 and will use the L-thrusters and the
axial (Z) thrusters to achieve a delta velocity of about 2.3 m/sec. Total
delta velocity from the TCM is expected to be about 21 m/sec.
6. The first three portions of TCM-14 consisted entirely of lateral burns
with each portion containing six nearly identical burn segments. The
spacecraft performance throughout the maneuver activity was normal and near
expected levels. In particular, the RPM tank pressures and temperatures were
normal throughout the 18 burn segments. After the second segment a portion A,
a sequence planned spin correction and pointing correction activity was
performed. This correction reduced an accumulated 20 mrad pointing error to
about 4 mrad. Similarly, other sequence planned pointing corrections were
performed after burn segments 4 and 6. Preliminary radio navigation data for
TCM-14A indicates about a two percent overburn. TCM-14B and TCM-14C portion
were performed on August 5 and 6, respectively. These maneuver portions, like
TCM-14A, exhibited somewhat larger than expected accumulated pointing error.
Furthermore, it was observed that the accumulated pointing error gradually
decreased after each burn segment. The cause for this unexpected pointing
error behavior is unclear but it may suggest that one L-thruster is performing
about one to two percent above predict. Radio navigation data after TCM-14B
and TCM-14C indicates about a 1.6 and 1.1 percent overburn, respectively.
The integrated 3-portion overburn is about 1.4 percent. The final portion,
TCM-14D, will be performed on August 7. This last portion consists of one
small (0.4m/sec) axial burn followed by a three segment lateral burn of
2.3m/sec.
7. The AC/DC bus imbalance measurements exhibited little change. The AC
measurement toggled 1 DN and reads 3.1 volts. The DC measurement increased
6 DN for a short time and then returned close to its previous value and now
reads 14.7 volts. Intermittently during pre-TCM burn segments, the DC
imbalance changed and then returned to its previous value. There was no
consistency as to when changes occurred, i.e., during burns or pre/post
burns. This measurement variation is consistent with the model developed
by the AC/DC special anomaly team.
8. The Spacecraft status as of August 6, 1992, is as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.16 rpm/Star Scanner
d) Spacecraft Attitude is approximately 3.1 degrees off-sun (lagging)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 264 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The TCM-14 final sequence and command product was approved by the Project
on July 31. The maneuver is scheduled to be performed from August 4 thru
August 7.
TRAJECTORY
As of noon Thursday, August 6, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 106,822,460 miles (1.16 AU)
Distance from Sun 160,260,630 miles (1.73 AU)
Heliocentric Speed 48,550 miles per hour
Distance from Jupiter 664,407,490 miles
Round Trip Light Time 19 minutes, 16 seconds
SPECIAL TOPIC
1. As of August 6, 1992, a total of 8108 real-time commands have been
transmitted to Galileo since Launch. Of these, 3230 were pre-planned in
the sequence design and 4878 were not. In the past week, 14 real time
commands were transmitted; 8 were pre-planned in the sequence design.
In addition, 5427 mini-sequence commands have been transmitted since
March 1991; 3269 were pre-planned and 2158 were not. In the past week,
44 mini-sequence commands (SITURN) were transmitted. Major command
activities this week included SITURN, EUV MRO, and power reconfiguration
activities.
2. The unexpected lock changes observed during the DSS-63 (Madrid 70
meter antenna) pass are believed similar to the many others observed during
the past two years. The tracking conditions for this recent event appears
similar to some of those observed on previous occurrences. There was no
evidence that the spacecraft received or issued a command during the
unexpected lock change. This recent lock change information was passed to
the team working the lock change ISAs.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | You can't hide broccoli in
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a glass of milk -
|_____|/ |_|/ |_____|/ | anonymous 7-year old.
Article: 1680
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 08/10/92
Date: 11 Aug 92 08:07:19 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 10, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and is
transmitting coded telemetry data at 40 bps.
Today, the EE-7 (Earth-Earth #7) stored sequence went active at 0810 PDT.
This stored sequence load controls spacecraft activities until November 23.
Tomorrow, no spacecraft activities are scheduled; tracking is over DSS-43
(Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | You can't hide broccoli in
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a glass of milk -
|_____|/ |_|/ |_____|/ | anonymous 7-year old.
Article: 1683
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 08/11/92
Date: 12 Aug 92 04:44:22 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 11, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry data at 40 bps.
Yesterday, the EPD (Energetic Particles Detector) instrument was returned
to sector 4 from sector 0 (the predicted least contamination position
for TCM-14).
Today, no spacecraft activities are scheduled; tracking is over DSS-43
(Canberra 70 meter antenna).
Tomorrow, no spacecraft activities are scheduled; tracking is over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | You can't hide broccoli in
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a glass of milk -
|_____|/ |_|/ |_____|/ | anonymous 7-year old.
Article: 1700
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 08/13/92
Date: 14 Aug 92 02:34:18 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 13, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry data at 40bps. The period from August 10
through August 21 was reserved by the Project as a High Gain Antenna (HGA)
activity window with no background sequence activities scheduled in the now
executing EE-7 (Earth-Earth 7) sequence. No HGA activities will take place
during this window. Tracking is scheduled over DSS-43 (Canberra 70 meter
antenna) through Friday of this week.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | You can't hide broccoli in
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a glass of milk -
|_____|/ |_|/ |_____|/ | anonymous 7-year old.
Article: 1709
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 08/14/92
Date: 15 Aug 92 00:21:50 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 7 - 13, 1992
SPACECRAFT
1. On August 7, the final portion of TCM-14 (Trajectory Correction
Maneuver #14), TCM-14D, was performed consisting of one small (0.4 m/sec)
axial burn followed by a three segment lateral burn of 2.3 m/sec. The
spacecraft performance throughout the maneuver activity was normal and near
expected levels. In particular, the RPM (Retro-Propulsion Module) tank
pressures and temperatures were normal throughout the four burn segments.
Radio navigation data after TCM-14D indicated about a 1.3 percent overburn.
The integrated 4-portion overburn was about 1.4 percent.
2. On August 7, the EE-7 (Earth-Earth 7) sequence memory load was uplinked
to the spacecraft. This sequence covers spacecraft activities from
August 10, 1992 to November 23, 1992. The sequence was loaded on the
spacecraft without incident.
3. On August 10, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.
4. On August 10, the Energetic Particle Detector (EPD) was returned to
Sector 4 from Sector 0 after the completion of TCM-14. The EPD instrument
was placed in Sector 0 for TCM-14 because it was the predicted least
contamination position for the maneuver.
5. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement increased 1 DN and reads 3.3 volts. The DC measurement has
ranged from 103 DN (11.9 volts) to 160 DN (18.9 volts) and now reads 127 DN
(14.9 volts). These measurement variations are consistent with the model
developed by the AC/DC special anomaly team.
6. The Spacecraft status as of August 13, 1992, is as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.16 rpm/Star Scanner
d) Spacecraft Attitude is approximately 6 degrees
off-sun (lagging) and 40 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science - UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 184 hours
TRAJECTORY
As of noon Thursday, August 13, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 97,738,600 miles (1.05 AU)
Distance from Sun 156,757,800 miles (1.69 AU)
Heliocentric Speed 49,700 miles per hour
Distance from Jupiter 660,750,900 miles
Round Trip Light Time 17 minutes, 38 seconds
SPECIAL TOPIC
1. As of August 13, 1992, a total of 8109 real-time commands have been
transmitted to Galileo since Launch. Of these, 3231 were pre-planned in
the sequence design and 4872 were not. In the past week, 1 real time command
was transmitted and pre-planned in the sequence design. In addition, 5427
mini-sequence commands have been transmitted since March 1991; 3269 were
pre-planned and 2158 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | You can't hide broccoli in
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a glass of milk -
|_____|/ |_|/ |_____|/ | anonymous 7-year old.
|
| 560.670 | Update - August 17 | VERGA::KLAES | Slaves to the Metal Hordes | Fri Aug 21 1992 22:08 | 28 |
| Article: 1732
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 08/17/92
Date: 18 Aug 92 08:01:01 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 17, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry data at 40bps. The period from August 10
through August 21 was reserved by the Project as a High Gain Antenna (HGA)
activity window with no background sequence activities scheduled in the now
executing EE-7 (Earth-Earth 7) sequence. No HGA activities will take place
during this window. Tracking is scheduled over DSS-43 (Canberra 70 meter
antenna) through Friday of this week.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Optimists live longer
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | than pessimists.
|_____|/ |_|/ |_____|/ |
|
| 560.671 | Updates - August 21-28 | VERGA::KLAES | All the Universe, or nothing! | Tue Sep 01 1992 19:36 | 310 |
| Article: 1755
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 08/21/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 22 Aug 1992 02:30:32 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 14 - 20, 1992
SPACECRAFT
1. On August 17, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
2. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement decreased 1 DN and reads 3.1 volts. The DC measurement has
ranged from 118 DN (13.8 volts) to 132 DN (15.5 volts) and now reads 123 DN
(14.4 volts). These measurement variations are consistent with the model
developed by the AC/DC special anomaly team
3. The Spacecraft status as of August 20, 1992, is as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.16 rpm/Star Scanner
d) Spacecraft Attitude is approximately 8 degrees
off-sun (lagging) and 43 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 184 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-9 (Earth-Earth #9) Sequence Final Profile Design was approved by
the Project on August 17, 1992. This sequence covers spacecraft activities
from November 23, 1992 to December 5, 1992.
2. The dual Drive Actuator (DDA) pulse mini-sequence No. 3 memory load was
approved for generation by the Project on August 20, 1992. This mini-sequence
covers spacecraft activities from September 8, 1992 to September 11, 1992.
This mini-sequence will include two 2-second DDA motor turn on pulses, one
shortly after turning to a 45-degree off-sun attitude and the other just
before returning to a near sun-pointed attitude.
GDS (Ground Data Systems):
1. The September 1992 D1.0 software delivery activities are continuing.
A total of 28 program sets implementing 75 Software Change Requests (SCRs)
and correcting 181 Failure Reports (FRs) are planned for the D1.0 delivery.
The D1.0 deliveries will continue thru October 1992 and will provide updates
to uplink capabilities needed for Jupiter sequence planning and developments
activities as well as updates to downlink capabilities needed for Earth 2
support.
TRAJECTORY
As of noon Thursday, August 20, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 88,904,600 miles (.96 AU)
Distance from Sun 153,145,300 miles (1.65 AU)
Heliocentric Speed 51,000 miles per hour
Distance from Jupiter 656,795,900 miles
Round Trip Light Time 16 minutes, 4 seconds
SPECIAL TOPIC
1. As of August 20, 1992, a total of 8110 real-time commands have been
transmitted to Galileo since Launch. Of these, 3232 were pre-planned in
the sequence design and 4878 were not. In the past week, 1 real time command
was transmitted and pre-planned in the sequence design. In addition, 5427
mini-sequence commands have been transmitted since March 1991; 3269 were
pre-planned and 2158 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Optimists live longer
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | than pessimists.
|_____|/ |_|/ |_____|/ |
Article: 1775
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 08/25/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 26 Aug 1992 01:25:44 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 25, 1992
alileo Spacecraft is operating normally in the dual-spin mode and is
transmitting coded telemetry data at 40bps.
Yesterday, no spacecraft activity was scheduled. Tracking was performed
over DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, August 25, 1992, no spacecraft activity or tracking is scheduled.
Tomorrow, the routine RPM (Retro-Propulsion Module) 10-Newton thruster
"flushing" maintenance activity along with a Science Turn (SITURN), cruise
science Memory Readouts (MROs) and an Ultra Stable Oscillator (USO) test are
scheduled. Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna),
DSS-43, and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Optimists live longer
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | than pessimists.
|_____|/ |_|/ |_____|/ |
Article: 1786
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 08/26/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 27 Aug 1992 02:16:33 GMT
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
August 26, 1992
The Galileo spacecraft is 131 million kilometers (less than
82 million miles) from Earth today, closing at a rate of almost 2
million kilometers per day. Distance from the Sun is 241 million
kilometers, or 150 million miles, decreasing more slowly. The
round-trip communication time is 14 minutes, 47 seconds. The
spacecraft has now travelled almost 2.2 billion kilometers (1.36
billion miles) since launch, and has another 256 million
kilometers to go before the second Earth gravity assist in
December.
The spacecraft is ending a scheduled two-week quiescent
period; today it is conducting a routine thruster-maintenance
operation. It is also reading out stored data from the extreme
ultraviolet and dust detectors and the magnetometer for the first
time since the trajectory correction maneuver of August 4-7.
That maneuver, as planned, changed the spacecraft velocity about
21 meters per second (47 mph), both sideways and along the
direction of flight. A smaller maneuver is planned for early
October.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Optimists live longer
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | than pessimists.
|_____|/ |_|/ |_____|/ |
Article: 1794
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 08/27/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 28 Aug 1992 00:47:52 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 27, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps.
Yesterday, the routine RPM (Retro-Propulsion Module) 10-Newton thruster
"flushing" maintenance activity along with a Science Turn (SITURN), cruise
science Memory Readouts (MROs) and an Ultra Stable Oscillator (USO) test were
performed, as planned. Tracking was performed over DSS-14 (Goldtone 70 meter
antenna), DSS-43 (Canberra 70 meter antenna), and DSS-63 (Madrid 70 meter
antenna).
Today, August 27, 1992, no spacecraft activity is scheduled. Tracking
is scheduled over DSS-63.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Optimists live longer
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | than pessimists.
|_____|/ |_|/ |_____|/ |
Article: 1796
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 08/27/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 28 Aug 1992 05:48:25 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 21 - 27, 1992
SPACECRAFT
1. On August 24, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.
2. On August 26, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
maintenance activity was performed; 10 of the 12 thrusters were "flushed"
during the activity. The P-thrusters were not flushed because they were used
to perform science turn (SITURN) activities on the same day. Spacecraft
performance throughout the activity was normal.
3. On August 26, the spacecraft performed a 16.5-degree SITURN. The purpose
of this SITURN is to maintain the spacecraft within a plus or minus 10
degrees of the sun while within a solar distance of 1.6 AU.
4. On August 26, the Earth vector and Earth stars were updated to the
spacecraft's present attitude. This strategy is being employed such that if
spacecraft safing is invoked, the spacecraft will remain at the current
attitude instead of going to sun point. This will expedite spacecraft
recovery in the event of spacecraft safing.
5. On August 26, cruise science Memory Readouts (MROs) were performed for
the Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and
Magnetometer (MAG) instruments. Preliminary analysis indicates the data
was received properly.
6. On August 27, an Ultra-Stable Oscillator (USO) test was performed to
verify the health status of the USO and collect gravitational red shift
experiment data; long term trend analysis is continuing.
7. During the period of August 26 through August 27, a navigation cycle was
performed. This navigation cycle provided near-continuous acquisition of
two-way doppler and ranging data during three consecutive passes of the
spacecraft over DSS-14, DSS-43, and DSS-63. This data will improve orbit
determination in preparation for the TCM-15 (Trajectory Correction
Maneuver #15) scheduled for October 9.
8. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement increased 1 DN and reads 3.3 volts. The DC measurement has
ranged from 121 DN (14.1 volts) to 130 DN (15.2 volts) and now reads 130 DN
(15.2 volts). These measurement variations are consistent with the model
developed by the AC/DC special anomaly team.
9. The Spacecraft status as of August 27, 1992, is as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 10 degrees
off-sun (leading) and 24 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 184 hours
TRAJECTORY
As of noon Thursday, August 27, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 80,355,100 miles (.87 AU)
Distance from Sun 149,427,100 miles (1.61 AU)
Heliocentric Speed 52,300 miles per hour
Distance from Jupiter 652,523,900 miles
Round Trip Light Time 14 minutes, 32 seconds
SPECIAL TOPIC
1. As of August 27, 1992, a total of 8111 real-time commands have been
transmitted to Galileo since Launch. Of these, 3233 were pre-planned in
the sequence design and 4878 were not. In the past week, 1 real time command
was transmitted and pre-planned in the sequence design. In addition, 5427
mini-sequence commands have been transmitted since March 1991; 3269 were
pre-planned and 2158 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Optimists live longer
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | than pessimists.
|_____|/ |_|/ |_____|/ |
|
| 560.672 | Updates - September 4-10, 1992 | PRAGMA::GRIFFIN | Dave Griffin | Thu Sep 17 1992 12:52 | 143 |
|
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
September 4 - 10, 1992
SPACECRAFT
1. On September 8, realtime commands were sent to change the System Fault
Protection (SFP) AACS-INIT (Attitude and Articulation Control Subsystem)
pointing slot from the Earth to the Sun prior to the Dual Drive Actuator
(DDA) No. 3 pulse activities. This change will allow the spacecraft to
return to a sun-pointed attitude if an AACS Power on Reset (POR) occurs
during the DDA No. 3 pulse activities (see Special Topic No. 2).
2. On September 8, the DDA pulse mini-sequence memory load went active.
The warming turn to a 45-degree off-sun attitude commenced at approximately
1536 UTC and completed at 1608 UTC. The first of two motor turn on pulses
occurred at 1826 UTC for approximately two seconds, as planned. The DDA
motor temperature was approximately minus 12 degrees C at turn on. The DDA
motor current data analysis is in progress.
3. On September 9, after approximately 28 hours at the warming attitude, the
second motor turn on pulse occurred at 1916 UTC for approximately two seconds,
as planned. The DDA motor temperature was approximately plus 9 degrees C at
turn on. DDA motor current data playback completed at approximately 1921 UTC
on September 10 and data analysis is in progress. Additionally, the
spacecraft, under stored sequence control, was commanded back to a six degree
off-sun attitude at approximately 1923 UTC. After the sun acquisition, sun
gate data was collected to determine if an antenna rib is still obscuring the
sun gate signal. Preliminary data analysis indicates that the sun gate is
still obscured, indicating no ribs released; analysis is continuing.
4. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement remained unchanged and reads 3.3 volts. The DC measurement has
ranged from 120 DN (14.0 volts) to 140 DN (16.4 volts) and now reads 129 DN
(15.1 volts). These measurement variations are consistent with the model
developed by the AC/DC special anomaly team.
5. The Spacecraft status as of September 10, 1992, is as follows:
a) System Power Margin - 68 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.14rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 5 degrees
off-sun (leading)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are
powered on
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 206 hours
TRAJECTORY
As of noon Thursday, September 10, 1992, the Galileo Spacecraft
trajectory status was as follows:
Distance from Earth 64,280,500 miles (.69 AU)
Distance from Sun 141,694,300 miles (1.53 AU)
Heliocentric Speed 55,100 miles per hour
Distance from Jupiter 642,944,800 miles
Round Trip Light Time 11 minutes, 38 seconds
SPECIAL TOPIC
1. As of September 10, 1992, a total of 8114 real-time commands have been
transmitted to Galileo since Launch. Of these, 3236 were pre-planned in
the sequence design and 4878 were not. In the past week, 1 real time command
was transmitted and pre-planned in the sequence design. In addition, 5677
mini-sequence commands have been transmitted since March 1991; 3519 were
pre-planned and 2158 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
change a System Fault Protection parameter.
2. The Dual Drive Actuator (DDA) pulse mini-sequence No. 3 covers spacecraft
activities from September 8 to 11, 1992. The warming turn to a 45-degree
off-sun attitude along with the first DDA two second motor turn on pulse
occurred on September 8. The spacecraft remained at the warming attitude for
approximately 28 hours. The second DDA two second motor turn on pulse
occurred just prior to turning back to approximately a 6 degree off-sun
attitude. Sun gate data was collected on September 10. The star scanner
checkout along with the collection of wobble data is scheduled for
September 11.
GALILEO STATUS REPORT
September 9, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps.
Yesterday, the turn to a 45 degree warming attitude along with
a first of two DDA (Dual Drive Actuator) motor turn on pulses was performed
over DSS-43 (Canberra 70 meter antenna), as planned.
Today, September 9, 1992, the second DDA motor turn on pulse along
with a turn back to a Sun pointed attitude is scheduled over DSS-43.
Tomorrow, the data playback of the second DDA motor turn on pulse is
scheduled over DSS-43.
GALILEO STATUS REPORT
September 10, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps.
Yesterday, the second DDA (Dual Drive Actuator) motor turn on pulse along
with a turn back to a Sun pointed attitude was performed over DSS-43
(Canberra 70 meter antenna), as planned.
Today, September 10, 1992, the data playback of the second DDA motor
turn on pulse is scheduled over DSS-43, along with collection of sungate data.
Tomorrow, real-time commands are scheduled to check out the scan scanner,
reacquire celestial reference, and collect precise wobble estimates.
Tracking is scheduled over DSS-43.
GALILEO STATUS REPORT
September 11, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps.
Yesterday, the data playback of the second DDA (Dual Drive Actuator)
motor turn on pulse was conducted over DSS-43 (Canberra 70 meter antenna),
along with collection of sungate data.
Today, September 11, 1992 real-time commands are scheduled to check out
the scan scanner, reacquire celestial reference, and collect precise wobble
estimates. Tracking is scheduled over DSS-43.
Over the weekend, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43, DSS-63 (Madrid 70 meter antenna), and DSS-14
(Goldstone 70 meter antenna).
|
| 560.673 | Updates - September 14-23 | VERGA::KLAES | All the Universe, or nothing! | Thu Sep 24 1992 17:28 | 266 |
| Article: 1946
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 09/14/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 15 Sep 1992 05:31:48 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 14, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps.
Over the weekend, no spacecraft activity was scheduled. Tracking was
performed over DSS-43 (Canberra 70 meter antenna), DSS-63 (Madrid 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, September 14, 1992, the real-time commands were scheduled to
change a system fault protection parameter and to update a acquisition
sensor parameter. Tracking is scheduled over DSS-43 and DSS-63.
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Anything is impossible if
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you don't attempt it.
|_____|/ |_|/ |_____|/ |
Article: 1967
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 09/16/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 17 Sep 1992 03:00:35 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 16, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps.
Yesterday, no spacecraft activity or tracking was scheduled.
Today, September 16, 1992, periodic thruster flushings and a
routine SITURN is planned. Tracking over DSS-43 (Canberra 70 meter antenna)
is scheduled.
Tomorrow, routine cruise science memory readouts are scheduled over
DSS-63 (Madrid 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Quiet people aren't the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | only ones who don't say
|_____|/ |_|/ |_____|/ | much.
Article: 1978
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 09/17/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 18 Sep 1992 02:10:26 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 17, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps.
Yesterday, periodic thruster flushings and a routine SITURN was
performed, as planned. Tracking was performed over DSS-43 (Canberra 70
meter antenna).
Today, September 17, 1992, routine cruise science memory readouts along
with a USO (Ultra Stable Oscillator) test are scheduled over DSS-63
(Madrid 70 meter antenna).
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Quiet people aren't the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | only ones who don't say
|_____|/ |_|/ |_____|/ | much.
Article: 1995
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 09/18/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 19 Sep 1992 02:04:07 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
September 11 - 17, 1992
SPACECRAFT
1. On September 11, as part of the Dual Drive Actuator (DDA) No. 3 pulse
activities, real-time commands were sent to checkout the star scanner.
This activity was performed as a precaution to protect the star scanner
from "seeing" bright particles which could release if an HGA (High Gain
Antenna) rib released. Additionally, real-time commands were sent to open
the Star Scanner (SS) shutter and to reacquire celestial reference.
Precise wobble data was collected which indicated no change in the HGA rib
configuration. Also, real-time commands were sent to reconfigure the System
Fault Protection (SFP) AACS-INIT (Attitude and Articulation Control Subsystem)
pointing slot from the Sun to the Earth after the DDA pulse No. 3 activities.
This change will allow the spacecraft to lock up on the star set in the Earth
slot if an AACS Power on Reset (POR) occurs and maintain its currrent attitude.
2. During the period of September 12 through September 13 a navigation cycle
was performed. This navigation cycle provided near-continuous acquisition of
two-way doppler and ranging data during four consecutive passes of the
spacecraft over DSS-43 (Canberra 70 meter antenna), DSS-63 (Madrid 70 meter
antenna), DSS-14 (Goldstone 70 meter antenna), and then back to DSS-43.
This data will improve orbit determination in preparation for the TCM-15
(Trajectory Correction Maneuver #15) scheduled for October 9.
3. On September 14, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.
4. On September 14, real-time commands were sent to modify the system fault
protection RPM (Retro-Propulsion Module) overpressure response. This change
was necessary to maintain a spacecraft configuration which was not vulnerable
to low probability Spin Bearing Assembly (SBA) debris induced CDS (Command
Data Subsystem) latching relay faults. This fault scenario was determined
several months ago as part of the Project's AC/DC bus imbalance anomaly
closeout effort.
5. On September 14, real-time commands were sent to update the acquisition
sensor parameters. Specifically, the sun pulse width parameter was updated
to compensate for the decreasing solar AU distance.
6. On September 16, a periodic RPM 10-Newton thruster maintenance activity
was performed. Ten of twelve thrusters were flushed during the activity.
The P-thrusters were not flushed because they were used to perform the science
turn (SITURN) activities on the same day. Spacecraft performance throughout
the activity was normal.
7. On September 16, the spacecraft performed a SITURN. The purpose of the
SITURN is to maintain the spacecraft within a plus or minus 10 degrees of the
sun while within a solar distance of 1.6 AU.
8. On September 16, the Earth vector and Earth stars were updated to the
spacecraft's present attitude. This change implements the post-fault attitude
maintenance strategy. If a fault occurs which terminates the currently
executing onboard sequence, the spacecraft will maintain its current attitude.
9. On September 17, cruise science Memory Readouts (MROs) were performed for
the Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and
Magnetometer (MAG) instruments. Preliminary analysis indicates the data
was received properly.
10. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement remained unchanged and reads 3.3 volts. The DC measurement has
ranged from 125 DN (14.6 volts) to 131 DN (15.3 volts) and now reads 130 DN
(15.2 volts). These measurement variations are consistent with the model
developed by the AC/DC special anomaly team.
11. The Spacecraft status as of September 17, 1992, is as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 5 degrees
off-sun (leading) and 20 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are
powered on
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 187 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-9 (Earth-Earth #9) Preliminary Sequence and Command Generation was
approved by the Project on September 17, 1992. This sequence covers
spacecraft activities from November 23, 1992 to December 5, 1992.
TRAJECTORY
As of noon Thursday, September 17, 1992, the Galileo Spacecraft
trajectory status was as follows:
Distance from Earth 56,817,100 miles (.61 AU)
Distance from Sun 137,693,900 miles (1.48 AU)
Heliocentric Speed 56,600 miles per hour
Distance from Jupiter 637,590,600 miles
Round Trip Light Time 10 minutes, 18 seconds
SPECIAL TOPIC
1. As of September 17, 1992, a total of 8206 real-time commands have been
transmitted to Galileo since Launch. Of these, 3280 were pre-planned in
the sequence design and 4926 were not. In the past week, 92 real time
commands were transmitted; 44 were pre-planned in the sequence design and 48
were not. In addition, 5677 mini-sequence commands have been transmitted
since March 1991; 3519 were pre-planned and 2158 were not. In the past week,
no mini-sequence commands were transmitted. Major command activities this
week included commands to checkout the star scanner, open the star scanner
shutter and reacquire celestial reference, reconfigure the SFP AACS-INIT
pointing slot, reset the command loss timer, update the System Fault
Protection and modify the acquisition sensor parameters.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Quiet people aren't the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | only ones who don't say
|_____|/ |_|/ |_____|/ | much.
Article: 2034
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 09/23/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 24 Sep 1992 03:21:55 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 23, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps.
Yesterday, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna).
Today, September 23, 1992, no spacecraft activity is scheduled.
Tracking is scheduled over DSS-43.
Tomorrow, real-time commands are scheduled to configure CDS (Command
Data Subsystem) latching relays to the preferred state. Tracking is
scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Quiet people aren't the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | only ones who don't say
|_____|/ |_|/ |_____|/ | much.
|
| 560.674 | Current status please!! | KAOFS::R_YURKIW | | Thu Sep 24 1992 20:32 | 24 |
| Can someone clarify somethings for me.
Since the motor turn ons have been going on the first attempts stopped
after 200ms. Several replies back mention was made that one of the
attemps stopped after something slightly greater than 200ms and the
impression mentioned was that this was possibly due to some screw
turning motion.
The last two attempt that were made said that the 2 second turn on went
ahead but did not say if they stopped at the 200ms mark or if there was
any screw turns indicated.
I may have misread some of this but can someone in a nutshell summarize
for me what exactly happened the last few attempts to turn the motor
on. Is there some screw action indicated and if so is this good or not?
Any help to understand the current state of the situation would be
appreciated.
thanks in advance.
Roger
|
| 560.675 | Updates - September 24 to October 1 | VERGA::KLAES | All the Universe, or nothing! | Fri Oct 02 1992 20:00 | 198 |
| Article: 2044
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 09/24/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 25 Sep 1992 02:40:34 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 24, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
The period from September 20 through October 2 is reserved in the sequence
design as a HGA (High Gain Antenna) activity window with no background sequence
activity scheduled. No HGA activities are currently scheduled during this
window.
Today, September 24, 1992, real-time commands are scheduled to configure
CDS (Command Data Subsystem) latching relays to their preferred states.
Tracking is scheduled over DSS-43 (Canberra 70 meter antenna) through Friday
of this week.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Quiet people aren't the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | only ones who don't say
|_____|/ |_|/ |_____|/ | much.
Article: 2047
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update #2 - 09/24/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 25 Sep 1992 07:52:14 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
September 18 - 24, 1992
SPACECRAFT
1. On September 18, an Ultra-Stable Oscillator (USO) test was performed to
verify the health status of the USO and collect gravitational red shift
experiment data; long term trend analysis is continuing.
2. On September 21, a NO-OP command was sent to reset the command loss
timer to 264 hours, its planned value for this mission phase.
3. On September 24, real-time commands were sent to enable mission critical
CDS (Command Data Subsystem) latching relays and to disable the CDS master
enable. These actions prevent Spin Bearing Assembly (SBA) debris-induced
potential mission catastrophic failures by setting the mission critical
relays to their ultimate desired state and protects the master enable
function.
4. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement remained unchanged and reads 14 DN (3.3 volts). The DC
measurement has ranged from 123 DN (14.4 volts) to 131 DN (15.3 volts) and
now reads 129 DN (15.1 volts). These measurement variations are consistent
with the model developed by the AC/DC special anomaly team.
5. The Spacecraft status as of September 24, 1992, is as follows:
a) System Power Margin - 68 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 7 degrees
off-sun (leading) and 22 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 257 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Dual Drive Actuator (DDA) pulse mini-sequence No. 4 memory load was
approved for generation by the Project on September 21, 1992. This
mini-sequence covers spacecraft activities associated with the DDA 10-pulse
hammer test from October 12 to October 15.
TRAJECTORY
As of noon Thursday, September 24, 1992, the Galileo Spacecraft
trajectory status was as follows:
Distance from Earth 49,768,800 miles (.54 AU)
Distance from Sun 133,617,100 miles (1.44 AU)
Heliocentric Speed 58,200 miles per hour
Distance from Jupiter 631,824,900 miles
Round Trip Light Time 9 minutes, 2 seconds
SPECIAL TOPIC
1. As of September 24, 1992, a total of 8230 real-time commands have
been transmitted to Galileo since Launch. Of these, 3281 were pre-planned
in the sequence design and 4949 were not. In the past week, 24 real time
commands were transmitted; one was pre-planned in the sequence design and
23 were not. In addition, 5677 mini-sequence commands have been transmitted
since March 1991; 3519 were pre-planned and 2158 were not. In the past week,
no mini-sequence commands were transmitted. Major command activities this
week included commands to reset the command loss timer, enable CDS latching
relays and disable the CDS master critical enable.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Quiet people aren't the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | only ones who don't say
|_____|/ |_|/ |_____|/ | much.
Article: 2097
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/01/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 2 Oct 1992 06:17:40 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
September 25 - October 1, 1992
SPACECRAFT
1. On September 28, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.
2. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement increased 2DN and reads 16 DN (3.7 volts). The DC measurement
has ranged from 128 DN (15.0 volts) to 135 DN (15.8 volts) and now reads
134 DN (15.7 volts). These measurement variations are consistent with the
model developed by the AC/DC special anomaly team.
3. The Spacecraft status as of October 1, 1992, is as follows:
a) System Power Margin - 68 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 4 degrees
off-sun (leading) and 24 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 192 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-9 (Earth-Earth #9) final sequence and command generation package
was approved by the Project on September 29, 1992. This sequence covers
spacecraft activities from November 23, 1992 to December 5, 1992.
TRAJECTORY
As of noon Thursday, October 1, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 43,166,200 miles (.46 AU)
Distance from Sun 129,476,400 miles (1.39 AU)
Heliocentric Speed 59,800 miles per hour
Distance from Jupiter 625,618,900 miles
Round Trip Light Time 7 minutes, 50 seconds
SPECIAL TOPIC
1. As of October 1, 1992, a total of 8231 real-time commands have been
transmitted to Galileo since Launch. Of these, 3282 were pre-planned in
the sequence design and 4949 were not. In the past week, 1 real time command
was transmitted and pre-planned in the sequence design. In addition, 5677
mini-sequence commands have been transmitted since March 1991; 3519 were
pre-planned and 2158 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
|
| 560.676 | Updates - October 5-13 | VERGA::KLAES | All the Universe, or nothing! | Tue Oct 13 1992 22:17 | 366 |
| Article: 2115
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/05/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 6 Oct 1992 04:59:43 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 5, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
performed over DSS-63 (Madrid 70 meter antenna), DSS-14 (Goldstone 70 meter
antenna) and DSS-43 (Canberra 70 meter antenna).
Today, October 5, 1992, a sun vector update along with an Ultra
Stable Oscillator test is scheduled. Tracking is scheduled over DSS-14
and DSS-63.
Tomorrow, a periodic thruster flushing maintainence activity and SITURN
is scheduled. Real-time commands are also scheduled to configure the telemtry
rate to 1200 bps which has not have been sustainable since June 1991.
Tracking is scheduled over DSS-63 and DSS-42 (Canberra 34 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
Article: 2126
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/06/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 7 Oct 1992 02:37:55 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 6, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, a sun vector update along with an Ultra Stable Oscillator test
was performed, as planned. Tracking was scheduled over DSS-14 (Goldstone
70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, October 6, 1992, a periodic thruster flushing maintainence
activity and SITURN and a SITURN is scheduled, along with cruise
science Memory Readouts. Real-time commands are also scheduled to
configure the spacecraft telemetry rate to 1200 bps which has not have
been sustainable since June 1991. Tracking is scheduled over DSS-63
and DSS-42 (Canberra 34 meter antenna).
Tomorrow, spacecraft telemetry is scheduled to be changed to 40 bps
uncoded telemetry. Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
Article: 2147
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/07/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 8 Oct 1992 02:16:50 GMT
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
October 7, 1992
The Galileo spacecraft is less than 61 million kilometers (38 million
miles) from Earth. It is just over two months to the second and final
Earth Gravity Assist that will set its course leading to Jupiter
arrival on December 7, 1995.
The spacecraft health and performance are excellent. Yesterday the
telemetry data rate was switched from 40 to 1200 bits per second.
This was the first time since June 1991 that the spacecraft position
allowed high-rate engineering telemetry. Today the spacecraft reads
out cruise-science data collected over the last two and a half weeks.
Friday, October 9, Galileo will execute a small trajectory correction
maneuver, slightly increasing its speed and bending its flight path to
refine the Earth flyby conditions.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
Article: 2153
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/08/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 9 Oct 1992 02:19:50 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 8, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting uncoded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-63 (Madrid 70 meter antenna).
Today, October 8, 1992, spacecraft telemetry is scheduled to change to
1200 bps along with updating the associated telemetry map. Additionaly, the
TCM-15 (Trajectory Correction Maneuver #15) memory load is scheduled for
uplink as well as perfoming EPD (Energetic Particle Detector) maintainence
activity. Tracking is scheduled over DSS-43 (Canberra 70 meter antenna)
and DSS-63.
Tomorrow, TCM-15 is scheduled to execute. Also, the DDA-4 (Dual Drive
Actuator #4) memory sequence load will be uplinked. Tracking is scheduled
over DSS-63, DSS-14 (Goldstone 70 meter antenna), DSS-43 and DSS-12
(Goldstone 34 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
Article: 2164
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/09/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 10 Oct 1992 04:31:49 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
October 2 - 8, 1992
SPACECRAFT
1. During the period of October 3 through October 4, a navigation cycle was
performed. This navigation cycle provided near-continuous acquisition of
two-way doppler and ranging data during four consecutive passes of the
spacecraft over DSS-63 (Madrid 70 meter antenna). This data will improve
orbit determination in support of the TCM-15 (Trajectory Correction Maneuver
#15) scheduled for October 9.
2. On October 5, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.
3. On October 5, a routine sun vector update was performed. This sun vector
is valid through October 27.
4. On October 5, an Ultra-Stable Oscillator (USO) test was performed to
verify the health status of the USO and collect gravitational red shift
experiment data; long term trend analysis is continuing.
5. On October 6, real-time commands were sent to temporarily configure the
spacecraft telemetry rate to 1200 bps, which has not been sustainable since
June 1991. On October 7, the spacecraft was configured to 40 bps uncoded
telemetry and then back to 1200 bps on October 8.
6. On October 6, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
maintenance activity was performed; 10 of the 12 thrusters were "flushed"
during the activity. The P-thrusters were not flushed because they were used
to perform science turn (SITURN) activities on the same day. Spacecraft
performance throughout the activity was normal.
7. On October 7, the spacecraft performed a 14.5 degree SITURN. The purpose
of the SITURN was to maintain the spacecraft within plus or minus 13 degrees
of the sun while at the current solar distance.
8. On October 7, the Earth vector and Earth stars were updated to the
spacecraft's present attitude. This change implements the attitude
maintenance strategy required in the case of an AACS (Attitude and
Articulation Control Subsystem) POR (Power On Reset). If a fault occurs
which terminates the currently executing sequence, the spacecraft will
maintain its current attitude.
9. On October 7, cruise science Memory Readouts (MROs) were performed for
the Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and
Magnetometer (MAG) instruments. Preliminary analysis indicates the data
was received properly.
10. On October 8, spacecraft telemetry maps were updated for the 1200 bps
capability.
11. On October 8, the Trajectory Correction Maneuver (TCM-15) memory load was
uplinked to the spacecraft. During the initial attempt, one of the eight
TCM-15 messages was rejected by the spacecraft. The entire High Level Module
(HLM) sequencing memory was readout, verified and the rejected message
retransmitted and verified via memory readout. This commanding incident is
under investigation.
12. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 12DN to 16DN and now reads 16 DN (3.7 volts).
The DC measurement has ranged from 116 DN (13.5 volts) to 135 DN (15.8 volts)
and now reads 126 DN (14.7 volts). These measurement variations are
consistent with the model developed by the AC/DC special anomaly team.
13. The Spacecraft status as of October 8, 1992, is as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 11 degrees
off-sun (leading) and 16 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-1200 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 263 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Trajectory Correction Maneuver (TCM-15) design package was approved
by the Project on October 2, 1992. Additionally, the TCM-15 maneuver was
approved for transmission by the Project on October 7, 1992. TCM-15 is a one
portion maneuver scheduled to execute on October 9 consisting of one axial
segment and one lateral segment. The estimated total delta velocity for
TCM-15 is .716 m/s.
2. The EE-12 (Earth-Earth 12) Final Cruise Plan was approved by the Project
on October 5, 1992. This sequence covers spacecraft activities from
January 20, 1993 to April 12, 1993.
3. The Dual Drive Actuator (DDA) pulse mini-sequence No. 4 memory load was
approved for transmission by the Project on October 8. This mini-sequence
covers spacecraft activities associated with the DDA 10-pulse hammer test
from October 12 to October 15.
TRAJECTORY
As of noon Thursday, October 8, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 37,027,900 miles (.40 AU)
Distance from Sun 125,287,800 miles (1.35 AU)
Heliocentric Speed 61,600 miles per hour
Distance from Jupiter 618,941,500 miles
Round Trip Light Time 6 minutes, 44 seconds
SPECIAL TOPIC
1. As of October 8, 1992, a total of 8237 real-time commands have been
transmitted to Galileo since Launch. Of these, 3288 were pre-planned in the
sequence design and 4949 were not. In the past week, 6 real time commands were
transmitted and pre-planned in the sequence design. In addition, 5677
mini-sequence commands have been transmitted since March 1991; 3519 were
pre-planned and 2158 were not. In the past week, no mini-sequence commands
were transmitted. Major command activities this week included commands to
reset the command loss timer, configure the spacecraft telemetry rate to
1200 bps, and uplink the TCM-15 memory load.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
Article: 2174
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/12/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 13 Oct 1992 02:35:58 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 12, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting uncoded telemetry at 40 bps (bits/second).
Over the weekend, telemetry mode changes were performed.
Tracking was scheduled over DSS-12 (Goldstone 34 meter antenna), DSS-43
(Canberra 70 meter antenna), DSS-63 (Madrid 70 meter antenna), and DSS-14
(Goldstone 70 meter antenna).
Today, October 12, 1992, real-time commands are scheduled to update
system fault protection parameters in preparation for the DDA-4 (Dual Drive
Actuator #4) hammer test activities. The turn to a 45 degree off sun angle
for a 2 day HGA (High Gain Antenna) warmup is scheduled to begin at
4:13 PM PDT today. This turn precedes the hammer test later this week.
Tracking is scheduled over DSS-63.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-63, DSS-43 and DSS-42.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
Article: 2192
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/13/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 14 Oct 1992 03:40:58 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 13, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, real-time commands were sent to update system fault protection
parameters in preparation for the DDA-4 (Dual Drive Actuator #4) hammer test
activities. A turn to a 45 degree off sun angle for a two day HGA (High Gain
Antenna) warmup was conducted, as planned. Tracking was performed over DSS-63
(Madrid 70 meter antenna).
Today, October 13, 1992, no spacecraft activity is scheduled. Tracking
is scheduled over DSS-63 and DSS-43 (Canberra 70 meter antenna).
Tomorrow, the 10 pulse hammer test activity is scheduled to occur after
approximately 46 hours after warming attitude. Additionally, the sun
acquisition back from warming attitude is scheduled to occur at 4:45 PDT.
Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
|
| 560.677 | "The Antenna Problem" | PONIL::J_BUTLER | E poi, si muove... | Fri Oct 16 1992 21:06 | 122 |
| Article 50230 of sci.space:
Newsgroups: sci.space
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!caen!uwm.edu!linac!newsaintmail
From: higgins@fnala.fnal.gov (Bill Higgins-- Beam Jockey)
Subject: Galileo's antenna (was Re: Gallileo's antenna)
Message-ID: <1992Oct15.181719.1@fnala.fnal.gov>
Sender: daemon@linac.fnal.gov (The Background Man)
Nntp-Posting-Host: fnala.fnal.gov
Organization: Fermi National Accelerator Laboratory
References: <9210140332.AA04848@etu2.educ.ucalgary.ca>
Date: Fri, 16 Oct 1992 00:17:19 GMT
Lines: 107
In article <9210140332.AA04848@etu2.educ.ucalgary.ca>, dstevens@educ.ucalgary.ca (Douglas Stevens) writes:
> Does anyone know if NASA has managed to get Gallileo's antenna
> open yet?
Boy, this is becoming a Frequently Asked Question in sci.space... I'll
have to prepare something to add to the FAQ files.
The answer is "no." They are still trying cooling turns. Below is an
excerpt from a Galileo mission summary I recently wrote for science
teachers. (Keep it around, and we can all mail hundreds of copies to
the next person that asks this question...) It owes a lot to Jon
Leech's notes from the 11 June briefing, and to the videotape that
Ross Doyle of Fermilab made for me. Thanks again, guys.
THE ANTENNA PROBLEM
A number of "cooling turns" have been performed, where the antenna
mast is pointed so it's in the shadow of the spacecraft. As it cools
off, the mast shrinks a little, and the antenna ribs have to bend
more. Putting a strain on the ribs like this, over and over again,
may "walk" the stuck pins out of the sockets on the antenna mast. At
least, that's what the computer models say. So Galileo will continue
to perform cooling turns every couple of months.
In December 1992 and January 1993, Galileo will be closer to the Sun
than it ever will be again, and hence warmer. At this time cooling
turns will have their maximum effect. Galileo engineers will combine
these with "hammering" the deployment motor, turning them on and off
thousands of times. This will increase the force on the stuck ribs,
and gives the best hope of success in nudging them loose.
If the HGA still fails to open by next March, planners will begin to
follow a plan to complete the mission without it.
WHAT HAPPENS IF IT DOESN'T OPEN?
The High-Gain Antenna can transmit from Jupiter and Earth at rates up
to 110,000 bits per second. The Low-Gain Antenna is designed to
transmit at only 10 bits per second. If Galileo has to get along
without the HGA, its operators will have to get very clever. Here are
the steps planned:
--Improvements in ground antennas: The Deep Space Network will
install better amplifiers at the Canberra, Australia station, better
receivers at all stations, and will combine several dishes together to
support a bit rate of up to 100 bits/second through the LGA.
--Data compression: Galileo has multiple computers aboard.
"Stealing" the spare attitude control computer, JPL can program it to
process image data and "squeeze" it so that a picture can be
represented by 5 to 10 percent of the usual number of bits. Tricky
algorithms allow them to do this without serious loss of image
quality. Data compression is a hot topic in computer science on Earth
today-- for instance Compuserve's Graphical Interchange Format (GIF)
makes use of it.
--Error-correcting codes: Software will be installed aboard the
spacecraft to encode data in better formats that are resistant to
errors or noise. This will enable Galileo to transmit at a higher data
rate where errors are more likely. (The modem on your computer
probably uses error-detecting or error-correcting codes.)
--Flyby vs. coasting: It has always been planned that Galileo will
spend short periods doing close flybys of the Galilean moons,
followed by long, slow loops (typically one or two months, sometimes
longer) around Jupiter before the next flyby. If data are crammed
into the tape recorder during a week or so during a satellite
encounter, Galileo can take several weeks to process and transmit the
results to the ground. It will be possible to get nearly as much
science done as with the original mission, where the satellites are
concerned. But some other aspects will not do as well.
The first major Galileo mission objective is direct measurement of
pressures, temperatures, chemistry, and other properties of Jupiter's
atmosphere when the probe parachutes into the giant planet. This will
happen on Day One of the orbiter's Jovian orbit-- 7 December 1995.
The probe will transmit its findings to the orbiter during its
75-minute lifetime. The orbiter can manage to store all this
information on its recorder and play it back using only the Low-Gain
Antenna, so this part of the mission can be accomplished despite the
handicap.
The major sacrifice will be frequent coverage of Jupiter itself--
atmospheric scientists were hoping to make detailed and extensive
movies of the planet's weather, wind circulation, color changes, and
so forth. Since the total number of pictures will be reduced, these
studies will suffer.
The majority of Galileo's instruments produce a fairly modest stream
of bits, compared to the cameras. So data that are not pictures, such
as magnetic and particle measurements or ultraviolet spectra, should
be fairly manageable, and most of the original objectives of these
experiments should be met.
The Galileo science team estimates that despite the loss of the HGA,
about 70% of the scientific objectives of the mission could still be
met-- given hard work by many people on planet Earth over the next few
years. And who knows? The antenna might open after all. Keep an eye
on the news.
O~~* /_) ' / / /_/ ' , , ' ,_ _ \|/
- ~ -~~~~~~~~~~~/_) / / / / / / (_) (_) / / / _\~~~~~~~~~~~zap!
/ \ (_) (_) / | \
| | Bill Higgins Fermi National Accelerator Laboratory
\ / Bitnet: HIGGINS@FNAL.BITNET
- - Internet: HIGGINS@FNAL.FNAL.GOV
~ SPAN/Hepnet: 43011::HIGGINS
|
| 560.678 | High Gain Antenna Update | PONIL::J_BUTLER | Annoy the media! | Thu Oct 29 1992 15:23 | 106 |
| Article 2309 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!sdd.hp.com!zaphod.mps.ohio-state.edu!cs.utexas.edu!sun-barr!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo High Gain Antenna Update
Message-ID: <1992Oct28.235952.3602@news.arc.nasa.gov>
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.3-4
Keywords: Galileo, JPL
Sender: news@elroy.jpl.nasa.gov (Usenet)
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Reply-To: baalke@kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Thu, 29 Oct 1992 07:58:50 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 87
From "The Galileo Messenger"
September 1992
By Bill O'Neil, Galileo Project Manager
In just a few months, on December 8, 1992, Galileo will complete the VEEGA
(Venus-Earth-Earth gravity assist) phase of its trajectory to Jupiter. EGA2,
(Earth Gravity Assist #2) on December 8, will boost Galileo into its three-year,
direct, Earth-to-Jupiter heliocentric transfer orbit. EGA2 is a very
significant milestone. And, once again, we are looking forward to some
spectacular observations of the Moon and Earth.
We have not yet succeeded in freeing the stuck ribs of the High Gain
Antenna (HGA). Fortunately, the most aggressive actions by far are still
ahead of us. The thermal cycling of the HGA by warming and cooling turns
to "stroke" the HGA central tower to try to walk the stuck locating pins out
of their receptacles was abandoned in July after the seventh cycle. Performing
seven cycles without even one rib releasing demonstrated that this technique
cannot free the ribs -- either the parameters are too adverse or the pin-
walking model does not adequately represent what is restraining the ribs.
It is well to remember that, due to thermal contraction, the HGA was not
at assembly dimensions at the April 1991 deploy attempt [this was when the
first deployment of the HGA was attempted] or at any time since then. Three
weeks after EGA2, in the last week of December, we will have the first
opportunity to restore the HGA to assembly dimensions. Galileo will be 1.0
AU from the Sun, where a warming turn will expand the tower to assembly
length for the first time. While considered unlikely, it is possible that
this action alone will free the ribs.
"Hammering" the deployment system is our very best prospect to free the
ribs. While performing investigative testing on the flight spare HGA at JPL
early this year, it was discovered that pulsing the deploy motors rotated
the deployment ballscrew substantially beyond its continuous run stall point.
Following the extension of the tower, we will hammer the ballscrew as far as
it will rotate by pulsing the motors. During the April 1991 deploy attempt,
the ballscrew stalled at 5.1 turns. Our recent ground tests and motor pulse
test on the spacecraft indicate we can advance the ballscrew 1.5 turns by
a combination of running the motors continuously at warm temperatures
(windup) followed by about 1000 pulses. This will double the force in the
highest loaded rib deploy pushrod. There is a good chance that before
reaching the new hammer stall point, the rising force in the pushrod will
overcome the rib restraint and pop the rib free. The dynamic effect on the
deployment mechanism of this rib springing out could free the other ribs.
If this "zipper" action does not occur, then we will resume hammering the
now softer system. This will increase the force in the remaining stuck rib
pushrods by several factors. The hammering technique has the prospect of
actually yielding (permanently deforming) any stuck pins and receptacle
surfaces.
While the prospects of freeing the HGA by the above method are good, we
must be prepared for the possibility that the ribs will remain stuck. Earlier
this year, the Project, in conjunction with the Telecommunications and Data
Acquisition (TDA) organization at JPL, studied how to maximize the mission
return over the Low Gain Antenna (LGA). We have always known we could perform
the atmospheric entry Probe mission and put the Orbiter into Jupiter orbit
without the HGA. The challenge was to return Orbiter science, particularly
imaging, over the LGA. The joint Galileo and TDA study determined that
improvements in the Deep Space Network (DSN) antennas and arraying of
antennas in conjunction with data compression onboard the Galileo spacecraft
would enable the return of a tape recorder load of data each Jupiter orbit.
Each tape load could contain 200 to 400 images, as well as data from all the
other lower rate instruments. So, in our primary 10-orbit mission, we
could return 2000 to 4000 images. Most of these would be the highest
resolution satellite images that have always been a very special feature
of the Galileo mission. Field and particles data would be returned nearly
continuously at low rates. Our overall estimated science return for the
LGA mission in percentages of the primary HGA mission breaks down as:
atmospheric science, 80%; satellite science, 70%; and magnetospheric
science, 60%. NASA Headquarters has accepted our recommendation that we
proceed with the implementation of the LGA mission on March 1, 1993, if the
HGA is not deployed by then. The implementation will include new DSN
hardware and software and major new flight software for the Galileo Command
and Data Subsystem (CDS) and Attitude and Articulation Control Subsystem
(AACS). With or without the HGA, Galileo will be a spectacular mission
at Jupiter!
Finally, I am very pleased that an excellent Jupiter satellite tour
was designed and selected on schedule, May 1, and, concomitant with the
selection, the Project recommended and NASA enthusiastically approved the
August 1993 asteroid Ida encounter.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would
|_____|/ |_|/ |_____|/ | have given us candidates.
|
| 560.679 | Updates - October 14-28 | VERGA::KLAES | All the Universe, or nothing! | Tue Nov 03 1992 17:25 | 610 |
| Article: 2197
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/14/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 15 Oct 1992 03:21:26 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 14, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was performed
over DSS-63 (Madrid 70 meter antenna) and DSS-43 (Canberra 70 meter antenna).
Today, October 14, 1992, the 10 pulse hammer test activity is scheduled to
occur at approximately 2:55 PM PDT. Additionally, the sun acquisition back
from warming attitude is scheduled to begin at 4:45 PM PDT. Tracking is
scheduled over DSS-63.
Tomorrow, real-time command are scheduled to be sent to open the star
scanner shutter, reacquire celestial reference, collect wobble data, and to
update system fault protection parameters back to the pre-warming state.
Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
Article: 2207
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/15/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 16 Oct 1992 08:29:43 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
October 9 - 15, 1992
SPACECRAFT
1. On October 9, the Energetic Particle Detector (EPD) motor maintenance
exercise was performed which stepped the motor through its eight operating
positions and then returned it to Sector O which is the predicted least
contamination position in preparation for the execution of TCM-15 (Trajectory
Correction Maneuver #15). The motor maintenance exercise was successfully
verified by Memory Readout (MRO) commands. Additionally, the EPD was returned
to Sector 4 at the completion of the maneuver.
2. On October 9, the Trajectory Correction Maneuver (TCM-15) was performed
on the spacecraft. The maneuver used the spacecraft's axial (z) thrusters and
lateral thrusters to impart a predicted total delta velocity of 0.72 m/s.
This maneuver was executed at 1200 bps with the spacecraft pointed
approximately 16 degrees off the Earth.
The spacecraft's performance throughout the activity was normal. All
RPM (Retro-Propulsion Module) pressures and temperatures and attitude control
indicators were near predicted levels. After the axial and lateral burn
segments, the sequence planned spin corrections and pointing corrections were
not needed.
Preliminary radio tracking data indicates a 0.5 percent overburn for the
axial segment and a 1.2 percent overburn for the lateral segment.
3. On October 10, the Dual Drive Actuator (DDA-4) memory sequence load was
uplinked to the spacecraft without incident. This sequence load covers
spacecraft activities from October 12 to October 16 (see Special Topic No. 2).
4. On October 10, Delayed Action Commands (DACs) were sent to the spacecraft
to switch from 40 bps uncoded telemetry to 1200 bps coded telemetry on
October 12 just prior to initiation of the DDA-4 sequence memory load.
5. On October 12, real-time commands were sent to change the System Fault
Protection (SFP) AACS-INIT (Attitude and Articulation Control Subsystem)
pointing slot from the Earth to the Sun prior to the Dual Drive Actuator
(DDA-4) pulse activities. This change will allow the spacecraft to return to
a sun-pointed attitude if an AACS Power on Reset (POR) occurs during the
DDA-4 pulse activities (see Special Topic No. 2).
6. On October 12, cruise science Memory Readouts (MROs) were performed for
the Extreme Ultraviolet Spectrometer (EUV). Preliminary analysis indicates
the data was received properly.
7. On October 12, the DDA-4 memory sequence load went active. The warming
turn to a 45-degree off-sun attitude started at approximately 2313 UTC and
completed 28 minutes later at 2341 UTC (see Special Topic No. 2).
8. On October 14, Delayed Action Commands (DACs) were sent to turn off the
Plasma Detector supplemental heater after the sun acquisition to eliminate a
30-degree thermal cycle on the instrument.
9. On October 14, after approximately 46 hours at the warming attitude, real
time commands were sent to enable the High Gain Antenna (HGA) Dual Drive
Actuator (DDA) motor primary relays, pulse the motors 10 times with an on time
of 0.267 seconds followed by an off time of 0.534 seconds, and then safe the
primary relays and reset the command loss timer. The DDA motor temperature
was approximately plus 23.5 degrees C at turn on. DDA motor current data
analysis is in progress. Preliminary analysis indicates the motor current
during the 10 pulses was less than the stall current of 970 milliamps,
indicating some ballscrew rotation took place.
Additionally, the spacecraft under stored sequence control was commanded
back to a 5 degree off-sun attitude at approximately 2345 UTC. After the sun
acquisition, sun gate data was collected to determine if an antenna rib is
still obscuring the sun gate signal. Preliminary data analysis indicates that
the sun gate field of view is still obscured, indicating no ribs released;
analysis is continuing. Also, preliminary doppler tracking data collaborates
the sun gate data results.
10. On October 15, as part of the Dual Drive Actuator (DDA) No. 4 pulse
activities, real-time commands were sent to checkout the star scanner. This
activity was performed as a precaution to protect the star scanner from
"seeing" bright particles which could release if an HGA rib released
(see Special Topic No. 2).
11. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 12DN to 18DN and now reads 18 DN (4.1 volts).
The DC measurement has ranged from 117 DN (13.6 volts) to 141 DN (16.6 volts)
and now reads 129 DN (15.1 volts). These measurement variations are
consistent with the model developed by the AC/DC special anomaly team.
12. The Spacecraft status as of October 15, 1992, is as follows:
a) System Power Margin - 56 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 5 degrees
off-sun (leading) and 19 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-1200 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are
powered on
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 263 hours
GDS (Ground Data Systems):
1. Galileo Earth 2 Ground Data System (GDS) testing was conducted on October 6
and October 13, 1992 with the Galileo D1.0 ground system utilizing the MCCC
(Mission Control and Computer Center) real-time systems and the DSN (Deep Space
Network) Canberra Signal Processing Center (SPC 40). Test objectives were to
validate the successful integration of the Galileo D1.0 ground system with the
DSN and MCCC system that will be used to support the Earth 2 activities.
Real-time analysis indicated all objectives were successfully met, however
some post-test analysis of data is on-going in the MTS and PFOE areas.
TRAJECTORY
As of noon Thursday, October 15, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 31,353,400 miles (.34 AU)
Distance from Sun 121,071,200 miles (1.30 AU)
Heliocentric Speed 63,400 miles per hour
Distance from Jupiter 611,760,500 miles
Round Trip Light Time 5 minutes, 42 seconds
SPECIAL TOPIC
1. As of October 15, 1992, a total of 8324 real-time commands have been
transmitted to Galileo since Launch. Of these, 3367 were initiated in the
sequence design process and 4957 initiated in the real-time command process.
In the past week, 87 real time commands were transmitted: 79 were initiated
in the sequence design process and 8 initiated in the real time command
process. In addition, 5911 mini-sequence commands have been transmitted
since March 1991; 3753 were pre-planned and 2158 were not. In the past week,
234 mini-sequence commands were transmitted. Major command activities this
week included commands to reconfigure the telemetry rate, update system fault
protection parameters, turn off the PLS supplemental heater, pulse the DDA
motors, and checkout the star scanner.
2. The Dual Drive Actuator (DDA) pulse mini-sequence No. 4 covers spacecraft
activities from October 12 to October 16. The warming turn to a 45-degree
off-sun attitude occurred on October 12. The spacecraft remained at the
warming attitude for approximately 48 hours. The DDA 10-pulse hammer test
occurred after approximately 46 hours at the warming attitude. The sun
acquisition back to approximately a 5 degree off-sun attitude occurred on
October 14. Sun Gate data was collected on October 15. The star scanner
checkout along with the collection of wobble data is scheduled for October 16.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would of
|_____|/ |_|/ |_____|/ | given us candidates.
Article: 2212
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/16/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 17 Oct 1992 08:05:23 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 16, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, real-time commands were sent to check out and open the star
scanner shutter, reacquire celestial reference, collect wobble data, and to
update system fault protection parameters back to the pre-warming turn state,
as planned. Tracking was performed over DSS-63 (Madrid 70 meter antenna).
Today, October 16, 1992, real-time commands are scheduled to reconfigure
the spacecraft power state after the warming turn, to modify the system fault
protection parameters to be consistent with RPM (Retro-Propulsion Module)
power management strategy. Tracking is scheduled over DSS-63 and DSS-14
(Goldstone 70 meter antenna).
Over the weekend, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-14, DSS-43 (Canberra 70 meter antenna), on DSS-63 on
Saturday. No tracking is scheduled for Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would
|_____|/ |_|/ |_____|/ | have given us candidates.
Article: 2217
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/19/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 20 Oct 1992 05:00:20 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 19, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
The period from October 12 to October 23 was reserved in the sequence
as a HGA (High Gain Antenna) activity window with no background sequence
activity scheduled. Ten pulse Dual Drive Actuator hammer test activities was
performed during the period of October 12 through October 16.
No further HGA activities are currently scheduled during this window.
Tracking is scheduled over DSS-63 (Madrid 70 meter antenna) through Friday of
this week, with additional tracks over DSS-14 (Goldstone 70 meter antenna) and
DSS-43 (Canberra 70 meter antenna) on Thursday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would
|_____|/ |_|/ |_____|/ | have given us candidates.
Article: 2264
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/23/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 24 Oct 1992 00:13:38 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
October 16 - 22, 1992
SPACECRAFT
1. On October 16, as part of the Dual Drive Actuator (DDA) No. 4 pulse
activities, real-time commands were sent to open the Star Scanner (SS)
shutter and to reacquire celestial reference. Additionally, commands were
sent to place the spacecraft in scan Type 6 for the collection of precise
wobble data. The wobble data confirmed earlier sun gate and doppler
indications that there was no change in the HGA (High Gain Antenna) rib
configuration (no ribs released). Also, real-time commands were sent to
reconfigure the System Fault Protection (SFP) AACS-INIT (Attitude and
Articulation Control Subsystem) pointing slot from the sun to the Earth
after the DDA pulse No. 4 activities. This change will allow the spacecraft
to lock up on the star set in the Earth slot if an AACS Power on Reset (POR)
occurs and maintain its current attitude.
Additionally, commands were sent to turn off the Radioisotope
Thermoelectric Generator (RTG) boom heaters and disable their respective
temperature control monitors in order to maintain an appropriate
Retro-Propulsion Module (RPM) power profile. Also the System Fault Protection
(SFP) parameters for RPM thermal safing were modified to reflect this change
to the spacecraft configuration.
2. During the period of October 16 through October 18, a navigation cycle was
performed. This navigation cycle provided near-continuous acquisition of
two-way doppler and ranging data during four consecutive passes of the
spacecraft over DSS-63 (Madrid 70 meter antenna), DSS-14 (Goldstone 70 meter
antenna), DSS-43 (Canberra 70 meter antenna), and then back to DSS-63. This
data will help improve orbit determination in support of the TCM-16
(Trajectory Correction Maneuver #16) scheduled for November 13.
3. On October 19, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.
4. On October 22, real-time commands were sent to perform Extreme Ultraviolet
Spectrometer (EUV) Memory Readouts (MROs). Preliminary analysis indicates
the data was received properly.
5. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 16DN to 18DN and now reads 16 DN (3.7 volts).
The DC measurement has ranged from 129 DN (15.1 volts) to 155 DN (18.3 volts)
and now reads 136 DN (16.0 volts). These measurement variations are
consistent with the model developed by the AC/DC special anomaly team.
6. The Spacecraft status as of October 22, 1992, is as follows:
a) System Power Margin - 76 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 2 degree
off-sun (lagging) and 21 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-1200 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 262 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-11 (Earth-Earth 11) Final Profile Design package was approved by
the Project on October 22, 1992. This sequence covers spacecraft activities
from December 7 to December 28, 1992 including Earth 2 closest approach on
December 8.
GDS (Ground Data Systems):
1. A Probe Mission Readiness Test/Ground Data System Test was conducted
Sunday, October 18 with the DSN (Deep Space Network) SPC 60 (Signal
Processing Center in Madrid, Spain). Probe data were routed through the DSN
station processors to the Galileo MTS (MCCC Telemetry Subsystem) where it was
processed, displayed and routed to the Probe Flight Operations Equipment
(PFOE) in real-time. A compressed Probe tape was created for non-realtime
processing on the PFOE. Post test analysis of both the real-time data and
the compressed Probe tape is continuing.
2. The October System Engineers Monthly Report (SEMR) review was conducted
Thursday, October 22. A review of current Project and Institutional (MOSO &
DSN) system status was conducted. Pre-Earth 2 delivery schedules, Earth 2
readiness, past months accomplishments and potential problem areas were
discussed. No significant schedule changes or problems were reported.
TRAJECTORY
As of noon Thursday, October 22, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 26,135,200 miles (.28 AU)
Distance from Sun 116,851,200 miles (1.26 AU)
Heliocentric Speed 65,300 miles per hour
Distance from Jupiter 604,042,600 miles
Round Trip Light Time 4 minutes, 38 seconds
SPECIAL TOPIC
1. As of October 22, 1992, a total of 8357 real-time commands have been
transmitted to Galileo since Launch. Of these, 3386 were initiated in the
sequence design process and 4971 initiated in the real-time command process.
In the past week, 33 real time commands were transmitted: 19 were initiated
in the sequence design process and 14 initiated in the real time command
process. In addition, 5911 mini-sequence commands have been transmitted
since March 1991; 3753 were pre-planned and 2158 were not. In the past week,
no mini-sequence commands were transmitted. Major command activities this
week included commands to open the star scanner shutter and reacquire
celestial reference, select scan Type 6, update system fault protection
parameters, turn off RTG boom heaters and disable their temperature control
monitors, reset the command loss timer, and perform cruise science memory
readouts.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would
|_____|/ |_|/ |_____|/ | have given us candidates.
Article: 2293
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/27/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 28 Oct 1992 04:10:27 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 27, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, delta DOR (Differential One-way Ranging) passes
were peformed over DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid
70 meter antenna). Tracking was also performed over DSS-43 (Canberra
70 meter antenna).
Today, October 27, 1992, a routine RPM (Retro-Propulsion Module)
10 Newton thruster flushing maintainence activity, science turn, and an
Earth vector/Earth star updates are scheduled, along with delta DOR passes
over DSS-14 and DSS-63, and also over DSS-14 and DSS-43.
Tomorrow, delta DOR are schedule over DSS-14 and DSS-43 along with a
USO (Ultra Stable Oscillator) test. Tracking is also schedule over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would
|_____|/ |_|/ |_____|/ | have given us candidates.
Article: 2299
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/26/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 27 Oct 1992 03:29:14 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 26, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Over the weekend, no spacecraft activity or tracking was scheduled.
Today, October 26, 1992, delta DOR (Differential One-way Ranging) passes
are being peformed over DSS-14 (Goldstone 70 meter antenna) and DSS-63
(Madrid 70 meter antenna). Tracking was also performed over DSS-43 (Canberra
70 meter antenna).
Tomorrow, a routine RPM (Retro-Propulsion Module) 10 Newton thruster
flushing maintainence activity, science turn-on, and an earth vector star
update are scheduled, along with delta DOR passes over DSS-14 and DSS-63, and
also DSS-14 and DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would
|_____|/ |_|/ |_____|/ | have given us candidates.
Article: 2308
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/28/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 29 Oct 1992 02:53:44 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
October 28, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, a routine RPM (Retro-Propulsion Module) 10 Newton thruster
flushing maintainence activity, science turn, and an Earth vector/Earth star
updates were performed as planned, along with delta DOR (Differential One-way
Ranging) passes over DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid
70 meter antenna) , and also over DSS-14 and DSS-43 (Canberra 70 meter
antenna).
Today, October 28, 1992, delta DOR passes are schedule over DSS-14 and
DSS-43, along with a USO (Ultra Stable Oscillator) test. Tracking is
scheduled over DSS-63.
Tomorrow, a CDS-A (Command Data Subsystem) memory verification test is
scheduled. Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would
|_____|/ |_|/ |_____|/ | have given us candidates.
Article: 2311
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo High Gain Antenna Update
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 29 Oct 1992 07:58:50 GMT
From "The Galileo Messenger"
September 1992
By Bill O'Neil, Galileo Project Manager
In just a few months, on December 8, 1992, Galileo will complete the VEEGA
(Venus-Earth-Earth gravity assist) phase of its trajectory to Jupiter. EGA2,
(Earth Gravity Assist #2) on December 8, will boost Galileo into its three-year,
direct, Earth-to-Jupiter heliocentric transfer orbit. EGA2 is a very
significant milestone. And, once again, we are looking forward to some
spectacular observations of the Moon and Earth.
We have not yet succeeded in freeing the stuck ribs of the High Gain
Antenna (HGA). Fortunately, the most aggressive actions by far are still
ahead of us. The thermal cycling of the HGA by warming and cooling turns
to "stroke" the HGA central tower to try to walk the stuck locating pins out
of their receptacles was abandoned in July after the seventh cycle. Performing
seven cycles without even one rib releasing demonstrated that this technique
cannot free the ribs -- either the parameters are too adverse or the pin-
walking model does not adequately represent what is restraining the ribs.
It is well to remember that, due to thermal contraction, the HGA was not
at assembly dimensions at the April 1991 deploy attempt [this was when the
first deployment of the HGA was attempted] or at any time since then. Three
weeks after EGA2, in the last week of December, we will have the first
opportunity to restore the HGA to assembly dimensions. Galileo will be 1.0
AU from the Sun, where a warming turn will expand the tower to assembly
length for the first time. While considered unlikely, it is possible that
this action alone will free the ribs.
"Hammering" the deployment system is our very best prospect to free the
ribs. While performing investigative testing on the flight spare HGA at JPL
early this year, it was discovered that pulsing the deploy motors rotated
the deployment ballscrew substantially beyond its continuous run stall point.
Following the extension of the tower, we will hammer the ballscrew as far as
it will rotate by pulsing the motors. During the April 1991 deploy attempt,
the ballscrew stalled at 5.1 turns. Our recent ground tests and motor pulse
test on the spacecraft indicate we can advance the ballscrew 1.5 turns by
a combination of running the motors continuously at warm temperatures
(windup) followed by about 1000 pulses. This will double the force in the
highest loaded rib deploy pushrod. There is a good chance that before
reaching the new hammer stall point, the rising force in the pushrod will
overcome the rib restraint and pop the rib free. The dynamic effect on the
deployment mechanism of this rib springing out could free the other ribs.
If this "zipper" action does not occur, then we will resume hammering the
now softer system. This will increase the force in the remaining stuck rib
pushrods by several factors. The hammering technique has the prospect of
actually yielding (permanently deforming) any stuck pins and receptacle
surfaces.
While the prospects of freeing the HGA by the above method are good, we
must be prepared for the possibility that the ribs will remain stuck. Earlier
this year, the Project, in conjunction with the Telecommunications and Data
Acquisition (TDA) organization at JPL, studied how to maximize the mission
return over the Low Gain Antenna (LGA). We have always known we could perform
the atmospheric entry Probe mission and put the Orbiter into Jupiter orbit
without the HGA. The challenge was to return Orbiter science, particularly
imaging, over the LGA. The joint Galileo and TDA study determined that
improvements in the Deep Space Network (DSN) antennas and arraying of
antennas in conjunction with data compression onboard the Galileo spacecraft
would enable the return of a tape recorder load of data each Jupiter orbit.
Each tape load could contain 200 to 400 images, as well as data from all the
other lower rate instruments. So, in our primary 10-orbit mission, we
could return 2000 to 4000 images. Most of these would be the highest
resolution satellite images that have always been a very special feature
of the Galileo mission. Field and particles data would be returned nearly
continuously at low rates. Our overall estimated science return for the
LGA mission in percentages of the primary HGA mission breaks down as:
atmospheric science, 80%; satellite science, 70%; and magnetospheric
science, 60%. NASA Headquarters has accepted our recommendation that we
proceed with the implementation of the LGA mission on March 1, 1993, if the
HGA is not deployed by then. The implementation will include new DSN
hardware and software and major new flight software for the Galileo Command
and Data Subsystem (CDS) and Attitude and Articulation Control Subsystem
(AACS). With or without the HGA, Galileo will be a spectacular mission
at Jupiter!
Finally, I am very pleased that an excellent Jupiter satellite tour
was designed and selected on schedule, May 1, and, concomitant with the
selection, the Project recommended and NASA enthusiastically approved the
August 1993 asteroid Ida encounter.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would
|_____|/ |_|/ |_____|/ | have given us candidates.
|
| 560.680 | Updates - October 30 to November 13 | VERGA::KLAES | All the Universe, or nothing! | Fri Nov 13 1992 19:29 | 665 |
| Article: 2325
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 10/30/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 31 Oct 1992 05:26:11 GMT
Fowarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
October 23 - 29, 1992
SPACECRAFT
1. On October 23, a routine sun vector update was performed. This sun vector
is valid through November 13.
2. On October 27 and 28, delta Differenced One-Way Range (DOR) passes were
performed over DSS-14/63 (Goldstone/Madrid) and DSS-14/43 (Goldstone/Canberra).
Initial results indicate that the delta DORs were successfully performed.
3. On October 27, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
4. On October 27, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
maintenance activity was performed; 10 of the 12 thrusters were "flushed"
during the activity. The P-thrusters were not flushed because they were used
to perform science turn (SITURN) activities on the same day. Spacecraft
performance throughout the activity was normal.
5. On October 27, the spacecraft performed a 17 degree SITURN. The purpose of
the SITURN was to maintain the spacecraft within plus or minus 13 degrees of
the sun while at the current solar distance.
6. On October 27, the Earth vector and Earth stars were updated to the
spacecraft's current attitude. This change implements the attitude maintenance
strategy required in the case of an AACS (Attitude and Articulation Control
Subsystem) POR (Power On Reset). If a fault occurs which terminates the
currently executing sequence, the spacecraft will maintain its current
attitude.
7. On October 28, Cruise Science Memory Readouts (MROs) were performed for
the Extreme Ultraviolet Spectrometer (EUV). Preliminary analysis indicates the
data was received properly. Subsequent to the MRO, the EUV was powered off,
as per plan. The HIC (Heavy Ion Counter) will be thus able to transmit data
when the Spacecraft is configured for the 7.68 kbps downlink on November 4.
8. On October 28, an Ultra Stable Oscillator (USO) test was performed to
verify the health status of the USO and collect gravitational red shift
experiment data; long term trend analysis is continuing.
9. On October 29, real-time commands were sent to perform a CDS (Command Data
Subsystem) memory verification test. Specifically, each memory location in
the standard and extended memory of the CDS A-string and B-string are being
readout. The purpose is to verify each memory location and identify any bad
memory locations. The test was in progress at the writing of this report.
10. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 16DN to 17DN and now reads 17 DN (3.9 volts).
The DC measurement has ranged from 131 DN (15.3 volts) to 138 DN (16.2 volts)
and now reads 136 DN (16.0 volts). These measurement variations are
consistent with the model developed by the AC/DC special anomaly team.
11. The Spacecraft status as of October 29, 1992, is as follows:
a) System Power Margin - 82 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 11 degree
off-sun (leading) and 7 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-1200 bps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 263 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL: None
GDS (Ground Data Systems):
1. A second Probe Mission Readiness Test/Ground Data System Test was
conducted Monday, October 26 with the DSN (Deep Space Network) SPC 60 (Signal
Processing Center in Madrid). Probe data were routed through the DSN station
processors to the Galileo MTS (MCCC Telemetry Subsystem) where it was
processed, displayed and routed to the Probe Flight Operations Equipment (PFOE)
in real-time. A compressed Probe tape was created for non-realtime processing
on the PFOE. Post test analysis of both the real-time data and the compressed
Probe tape is continuing. The first probe MRT (Mission Readiness Test) was
reported last week; analysis is complete and the test was successful.
TRAJECTORY
As of noon Thursday, October 29, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 34,380,800 km (.23 AU)
Distance from Sun 181,306,000 km (1.21 AU)
Heliocentric Speed 108,300 km per hour
Distance from Jupiter 958,755,200 km
Round Trip Light Time 3 minutes, 48 seconds
SPECIAL TOPIC
1. As of October 29, 1992, a total of 8584 real-time commands have been
transmitted to Galileo since Launch. Of these, 3613 were initiated in the
sequence design process and 4971 initiated in the real-time command process.
In the past week, 227 real time commands were transmitted: 227 were initiated
in the sequence design process and none initiated in the real time command
process. In addition, 5911 mini-sequence commands have been transmitted since
March 1991; 3753 were pre-planned and 2158 were not. In the past week, no
mini-sequence commands were transmitted. Major command activities this week
included commands to reset the command loss timer and perform a CDS memory
verification test.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If God had wanted us to
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | have elections, he would
|_____|/ |_|/ |_____|/ | have given us candidates.
Article: 2369
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/03/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 4 Nov 1992 04:58:44 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 3, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, real-time commands were sent to change the coded telemetry rate
from 1200 bps to 7.68 Kbps, in response to a request from the HIC (Heavy Ion
Counter) investigator. This data mode change allows observations of solar
activity which occurred earlier yesterday. Tracking was scheduled over DSS-63
(Madrid 70 meter antenna).
Today, November 3, 1992, a delta DOR (Differential One-way Ranging) pass
is scheduled over DSS-14 (Goldstone 70 meter antenna) and DSS-63. Tracking is
also scheduled over DSS-14, DSS-43 (Canberra 70 meter antenna) and DSS-63.
Tomorrow, a delta DOR pass is scheduled over DSS-14 and DSS-43.
Tracking is also scheduled DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Give people a second
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/ |_|/ |_____|/ |
Article: 2375
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 11/04/92
Date: 5 Nov 92 05:29:05 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 4, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, a delta DOR (Differential One-way Ranging) pass was scheduled
over DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
After configuring the telemetry rate to 7.68 Kbps, it was reported that four
of the UVS (Ultraviolet Spectrometer instrument) telemetry channels were not
in their expected state. Analysis is in process. The instrument health is
not threatened. Tracking was also scheduled over DSS-43 (Canberra 70 meter
antenna).
Today, November 4, 1992,a delta DOR pass is scheduled over DSS-14 and
DSS-43. Additionally, real-time commands are being scheduled to perform a
UVS memory readout to to verify the state of the instrument and its memory.
Tracking is also scheduled over DSS-63 and DSS-14.
Tomorrow, real-time commands are scheduled to configure system fault
protection parameters for the near Earth 2 operations. Continuous tracking
is scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Give people a second
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/ |_|/ |_____|/ |
Article: 2379
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/05/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 6 Nov 1992 07:39:52 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 5, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, a delta DOR (Differential One-way Ranging) pass was scheduled
over DSS-14 (Goldstone 70 meter antenna) and DSS-43 (Canberra 70 meter
antenna). Additionally, real-time commands were sent to perform a UVS
(Ultraviolet Spectrometer) memory readout to verify the state of the instrument
and its memory. Tracking was also scheduled over DSS-63 (Madrid 70 meter
antenna) and DSS-14.
Today, November 5, 1992, real-time commands are scheduled to configure
system fault protection parameters for the near Earth 2 operations.
Continuous tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, a DOR pass is scheduled over DSS-14 and DSS-43. Additionally,
the EPD (Energetic Particle Detector), PWS (Plasma Wave) and PLS (Plasma)
instruments are scheduled to be turned on. Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Give people a second
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/ |_|/ |_____|/ |
Article: 2386
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/06/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 7 Nov 1992 08:18:28 GMT
Fowarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
October 30 - November 5, 1992
SPACECRAFT
1. On October 31 and November 1, delta Differenced One-Way Range (DOR) passes
were performed over DSS-14/63 (Goldstone/Madrid) and DSS-14/43
(Goldstone/Canberra). Initial results indicate three of the four delta DOR
passes were successfully performed.
2. On November 2, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value for this mission phase.
3. On November 3, real-time commands were sent to change the downlink
telemetry rate from 1200 bps coded to 7.68 kbps coded. This allowed the Heavy
Ion Counter (HIC) instrument to transmit Low Rate Science (LRS) data two days
earlier than planned in the background sequence, collecting data on recent
solar flare activity.
4. On November 3, after the telemetry configuration to low rate science data
(7.68 kbps), visibility into the full engineering channels revealed that four
of the Ultraviolet Spectrometer (UVS) channels were not in their expected
state. Preliminary analysis indicates that a bit flip in one memory location
apparently occurred between the first and second instrument memory readouts on
October 15, 1992. The UVS team is still investigating the possible cause of
this anomaly. The instrument health and safety are not threatened.
5. On November 4, delta DOR passes were performed over DSS-14/63 and
DSS-14/43. Initial results indicate the one of the two delta DOR passes were
successfully performed.
6. On November 4, real-time commands were sent to verify the status of the
UVS microprocessor memory. The memory readouts confirm that a bit flip is
still present in the same memory location. Investigation into the cause of
the anomaly and actions to take are continuing.
7. On November 5, real-time commands were sent to configure the System Fault
Protection (SFP) for the near Earth 2 operations. Commanding was interrupted
for 1 hour 8 minutes due to a low power transmitter problem at DSS-63 (Madrid
70 meter antenna). Commanding was then resumed and all command activities
completed. Specifically, the Energetic Particle Detector (EPD) science
monitor was updated, thruster firing all clear response was enabled, and the
Plasma Wave (PWS) cold flag parameter was changed.
8. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 16DN to 17DN and now reads 17 DN (3.9 volts).
The DC measurement has changed significantly from 133 DN (15.6 volts) to
160 DN (18.9 volts) and now reads 137 DN (16.1 volts). These measurement
variations are consistent with the model developed by the AC/DC special
anomaly team.
9. The Spacecraft status as of November 5, 1992, is as follows:
a) System Power Margin - 82 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 7 degree
off-sun (leading) and 8 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-7.68kbps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- UVS, DDS, MAG, EPD, and HIC are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 260 hours
GDS (Ground Data Systems):
1. A Ground Data System Data Flow Test was conducted Tuesday, November 3
with the NIMS (Near Infrared Mapping Spectrometer) Processing Equipment (NPE)
following its relocation from 264-316 to 264-721. The data flow test was
successful. In addition, the 26 October Probe MRT (Mission Readiness Test)
post test analysis has been completed. All test objective were met and the
test was considered successful.
2. Since the start of 1200 bps telemetry operations last month, random
losses of data blocks have been noticed during Madrid passes. The problem is
currently under investigation with resolution targeted by November 16th
before the start of the Probe Mission Sequence Test (MST) with the spacecraft
(November 20th). Occurrences of the problem during the Madrid pass Thursday
were correlated with heavy communication loading including simultaneous passes
and VLBI (Very Long Baseline Interferometry) data replays. The DSN (Deep
Space Network) is establishing procedures to monitor and minimize the
communication loads at Madrid during critical Earth 2 support.
TRAJECTORY
As of noon Thursday, November 5, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 27,366,500 km (.18 AU)
Distance from Sun 174,661,900 km (1.17 AU)
Heliocentric Speed 111,600 km per hour
Distance from Jupiter 944,473,000 km
Round Trip Light Time 3 minutes, 0 seconds
SPECIAL TOPIC
1. As of November 5, 1992, a total of 8636 real-time commands have been
transmitted to Galileo since Launch. Of these, 3659 were initiated in the
sequence design process and 4977 initiated in the real-time command process.
In the past week, 52 real time commands were transmitted: 46 were initiated in
the sequence design process and 6 initiated in the real time command process.
In addition, 5911 mini-sequence commands have been transmitted since March
1991; 3753 were pre-planned and 2158 were not. In the past week, no
mini-sequence commands were transmitted. Major command activities this week
included commands to reset the command loss timer, switch to 7.68 coded
telemetry data, perform memory readouts of the UVS instrument, and update
system fault protection for near Earth 2 operations.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Give people a second
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/ |_|/ |_____|/ |
Article: 2421
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/09/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 10 Nov 1992 03:10:28 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 9, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Over the weekend, the Radio Science gravity wave experiment system test
began, along with a delta DOR (Differential One-way Ranging) pass over DSS-14
(Goldstone 70 meter antenna) and DSS-63 (Madrid 70 meter antenna). Continuous
tracking is scheduled over DSS-14, DSS-43 (Canberra 70 meter antenna) and
DSS-63.
Today, November 9, 1992, the Radio Science gravity wave experiment system
test is continuing with scheduled completion by Friday of this week.
Continuous tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, continuous tracking is scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Give people a second
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/ |_|/ |_____|/ |
Article: 2436
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/10/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 11 Nov 1992 07:36:20 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 10, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, the Radio Science gravity wave experiment system test
continued with scheduled completion by Friday of this week. Continuous
tracking is scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43
(Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, November 10, 1992, no spacecraft activity is scheduled.
Continuous tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, a sun vector is scheduled to be updated. Continuous tracking
is scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Give people a second
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/ |_|/ |_____|/ |
Article: 2439
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/11/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 12 Nov 1992 04:47:42 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 11, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, the Radio Science gravity wave experiment system test
continued with the scheduled completion by Friday of this week. Continuous
tracking was performed over DSS-14 (Goldstone 70 meter antenna), DSS-43
(Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, November 11, 1992, a sun vector is scheduled to be updated.
Continuous tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, the TCM-16 (Trajectory Correction Maneuver #16) memory load is
scheduled to be uplinked. Continuous tracking is scheduled over DSS-14,
DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Give people a second
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/ |_|/ |_____|/ |
Article: 2443
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/12/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 13 Nov 1992 07:02:56 GMT
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
November 12, 1992
The Galileo spacecraft is operating normally in the dual-
spin mode and is transmitting coded telemetry at 7680 bits per
second, a change from the 1200-bit-per-second rate that was
executed on November 3. The spacecraft is less than 21 million
miles (13 million miles) from Earth now, and that distance is
decreasing at almost a million kilometers each day. Galileo's
actual speed in its solar orbit is almost 32 kilometers per
second (71,442 mph).
Today the command load for Galileo's sixteenth trajectory
correction maneuver is being transmitted to the spacecraft. The
maneuver, amounting to less than 1 meter per second in velocity
change, will refine Galileo's trajectory for its second and last
Earth gravity assist, to occur December 8, 1992; that in turn
will send the spacecraft to Jupiter in late 1995.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Give people a second
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/ |_|/ |_____|/ |
Article: 2449
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/13/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 14 Nov 1992 01:00:32 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
November 6 - 12, 1992
SPACECRAFT
1. On November 6, real-time commands were sent to turn the Ultraviolet
Spectrometer (UVS) instrument off in response to the anomalous state of the
instrument observed when the telemetry rate was configured to Low Rate Science
(LRS). Possible causes of this anomaly include the TCC-244 read disturb
problem. The UVS team is continuing its investigation of the anomaly and the
implementation of a recovery plan.
2. On November 6, delta Differenced One-Way Range (DOR) passes were performed
over DSS-14/63 (Goldstone/Madrid) and DSS-14/43 (Goldstone/Canberra). Initial
results indicate both of the delta DOR passes were successfully performed.
3. On November 6, a NO-OP command was sent to reset the command loss timer
for both strings of the Command and Data Subsystem (CDS) computer to 264 hours,
its planned value for this mission phase.
4. On November 6, the Plasma Wave (PWS) and Plasma Detector (PLS) instruments
were turned on. Spacecraft telemetry indicates the PWS search coil is
operating normally, even after the severe cold temperature environment it went
through during the High Gain Antenna (HGA) warming turn/cooling turn campaign.
Additionally, the Energetic Particle Detector (EPD) memory was loaded and
checked by memory readouts, along with configuration changes to the
magnetometer sensor.
5. On November 7, the radio science gravity wave experiment system test began
and will continue through November 13. This system test is in preparation for
a joint experiment with Ulysses and Mars Observer in March/April 1993.
6. On November 8, a delta Differenced One-Way Range (DOR) pass was performed
over DSS-14/63 and preliminary indications are that it was successfully
performed.
7. On November 9, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
8. On November 11, a routine sun vector update was performed. This sun
vector is valid through November 25.
9. On November 12, the Energetic Particle Detector (EPD) motor was turned on
and the instrument stepped to Sector 0 which is the predicted least
contamination position in preparation for the execution of TCM-16 (Trajectory
Correction Maneuver #16).
10. On November 12, the Trajectory Correction Maneuver (TCM-16) memory load
was uplinked to the spacecraft without incident.
11. On November 12, Delayed Action Commands (DACs) were sent to turn the
Photometric Calibration Target (PCT) off/on and off again for the purpose of
Retro-Propulsion Module (RPM) tank pressure/temperature management.
12. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 16DN to 17DN and now reads 17 DN (3.9 volts).
The DC measurement has ranged from 131 DN (15.3 volts) to 140 DN (16.4 volts)
and now reads 139 DN (16.3 volts).These measurement variations are consistent
with the model developed by the AC/DC special anomaly team.
13. The Spacecraft status as of November 12, 1992, is as follows:
a) System Power Margin - 72 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 7 degree
off-sun (lagging) and 8 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-7.68kbps (coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- PWS, PLS, EPD, MAG, HIC and DDS are
powered on
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 186 hours
Time To Initiation - 260 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Trajectory Correction Maneuver (TCM-16) design package was approved
by the Project on November 9, 1992. Also, the TCM-16 maneuver was approved
for transmission by the Project on November 12, 1992. TCM-16 is a one
portion maneuver scheduled to execute on November 13 consisting of one lateral
segment. The estimated total delta velocity for TCM-16 is .89 m/s.
GDS (Ground Data Systems):
1. A Telemetry Test was conducted with SPC-60 (Madrid Signal Processing
Center) on Tuesday, November 10 to isolate intermittent communication related
data losses being observed during flight support and to demonstrate performance
in the configuration to be used for Earth 2 high rate support. A
configuration was achieved which provided three hours of error-free
performance at the 28.8 kbps telemetry rate to be used for the Probe MST
(MCCC Telemetry Subsystem) and AFST. Prior to that period, there were data
loss problems and it is not clear what action at the station corrected the
problems (analysis of all logs and data is in progress). In addition, data
lock could not be maintained with the Type B TPA (Telemetry Processing
Assembly) at rates above 80.64 kbps. This same problem has been observed at
the other SPCs with Type B telemetry strings. This may reflect a performance
degradation introduced with the TPA B Op D software put on-line several months
ago and may be corrected by disabling recording of data at the TPA. Type A
TPAs do not exhibit this problem and will be prime for Earth 2 support.
Additional testing is being planned with SPC-60 early next week to demonstrate
the configurations that will be used for high rate Earth 2 flight support
including 28.8 kbps used for the Probe MST/AFST and 134.4 kbps used for high
rate science.
TRAJECTORY
As of noon Thursday, November 12, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 20,040,300 km (.13 AU)
Distance from Sun 167,289,500 km (1.12 AU)
Heliocentric Speed 115,500 km per hour
Distance from Jupiter 926,895,300 km
Round Trip Light Time 2 minutes, 18 seconds
SPECIAL TOPIC
1. As of November 12, 1992, a total of 8649 real-time commands have been
transmitted to Galileo since Launch. Of these, 3660 were initiated in the
sequence design process and 4989 initiated in the real-time command process.
In the past week, 13 real time commands were transmitted: 1 was initiated in
the sequence design process and 12 initiated in the real time command process.
In addition, 5911 mini-sequence commands have been transmitted since
March 1991; 3753 were pre-planned and 2158 were not. In the past week, no
mini-sequence commands were transmitted. Major command activities this week
included commands to turn the UVS instrument off, reset the command loss timer,
uplink TCM-16 memory load, and reconfigure the PCT heater.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Give people a second
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | chance, but not a third.
|_____|/ |_|/ |_____|/ |
|
| 560.681 | Updates - November 16-24 | VERGA::KLAES | All the Universe, or nothing! | Wed Nov 25 1992 18:00 | 453 |
| Article: 2468
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/16/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 17 Nov 1992 05:09:55 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 16, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Over the weekend, three delta DOR passes were scheduled over DSS-14/DSS-43
(Goldstone/Canberra), DSS-14/DSS-63 (Goldstone/Madrid), and DSS-14/DSS-43
again. Continuous tracking was performed over DSS-14, DSS-43 and DSS-63.
Today, November 16, 1992, a routine RPM (Retro-Propulsion Module)
10-Newton thruster flushing maintainence activity, SITURN, and Earth vector
star update are scheduled, along with real-time telemetry mode change commands.
Continuous tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, no spacecraft activity is scheduled. Continuous tracking is
scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Learn to recognize the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | inconsequential, then
|_____|/ |_|/ |_____|/ | ignore it.
Article: 2478
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/17/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 18 Nov 1992 08:01:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 17, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, a routine RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintainence activity, SITURN, and Earth vector Earth star updates
were performed, along with real-time telemetry mode change commands, as
planned. Continuous tracking was performed over DSS-14 (Goldstone 70 meter
antenna), DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter
antenna).
Today, November 17, 1992, no spacecraft activity is scheduled. Tracking
is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, real-time are scheduled to turn on the UVS (Ultraviolet
Spectrometer) and configure it for science data collection. Continuous
tracking is scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Learn to recognize the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | inconsequential, then
|_____|/ |_|/ |_____|/ | ignore it.
Article: 2476
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/18/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 19 Nov 1992 03:29:18 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 18, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-14 (Goldstone 70 meter antenna), DSS-43 (Canberra 70 meter antenna)
and DSS-63 (Madrid 70 meter antenna).
Today, November 18, 1992, real-time commands are scheduled to turn on
the UVS (Ultraviolet Spectrometer) and configure it for science data
collection. Continuous tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, real-time commands are scheduled to change the telemetry bit
rate to 28.8 Kbps coded. Also, DACs (Delayed Action Commands) are scheduled
for transmission. These commands will turn ranging off, TWNC on and off, and
then ranging back on to optmize the telecommunications performance during the
Probe Mission Sequence Test on Friday. A delta DOR (Differential One-way
Ranging) pass is scheduled over DSS-14 and DSS-63. Continuous tracking is
scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Learn to recognize the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | inconsequential, then
|_____|/ |_|/ |_____|/ | ignore it.
Article: 2492
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/19/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 20 Nov 1992 12:02:13 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 19, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, real-time commands were sent to turn on the UVS
(Ultraviolet Spectrometer) and configure it for science data collection, as
planned. The UVS is now properly configured for the start of EE-9 (Earth-
Earth 9 sequence). Continuous tracking is scheduled over DSS-14 (Goldstone
70 meter antenna), DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid
70 meter antenna).
Today, November 19, 1992, real-time commands are scheduled to change the
telemetry bit rate to 28.8 Kbps. Also, DACs (Delayed Action Commands) are
scheduled for transmission. These commands will turn ranging off, TWNC on and
off, and then ranging back on to optimize the telecommunications performance
during the Probe Mission Sequence Test on Friday. A delta DOR (Differential
One-way Ranging) pass is scheduled over DSS-14 and DSS-63. Near continuous
tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, the Probe Mission Sequence test and a sun vector update are
scheduled. A delta DOR pass is scheduled over DSS-14 and DSS-43. Continuous
tracking is scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Learn to recognize the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | inconsequential, then
|_____|/ |_|/ |_____|/ | ignore it.
Article: 2495
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/20/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 21 Nov 1992 03:38:05 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
November 12 - 19, 1992
SPACECRAFT
1. On November 13, the Trajectory Correction Maneuver (TCM-16) was performed
on the spacecraft. The maneuver used the spacecraft's lateral thrusters to
impart a predicted total delta velocity of 0.89 m/s. This maneuver was
executed at 1200 bps with the spacecraft pointed approximately 7 degrees off
the Sun.
The spacecraft's performance throughout the activity was nominal. All
RPM (Retro-Propulsion Module) pressures and temperatures and attitude control
indicators were near predicted levels. After the lateral burn segment, the
sequence planned pointing correction was executed; the sequence planned spin
correction was not needed.
2. On November 14, after completion of TCM-16, the Energetic Particle Detector
(EPD) instrument was moved from Sector O (TCM safe position) to Sector 5 and
scanning operation initiated to continue science data collection. The science
scanning mode continued until November 17 at which time the EPD was moved to
Sector 4 and the motor turned off. The EPD instrument is continuing to
collect science data in Sector 4.
3. On November 14 and 15, delta Differenced One-Way range (DOR) passes were
performed over DSS-14/63 (Goldstone/Madrid) and DSS-14/43 (Goldstone/Canberra).
Initial results indicate the four delta DOR passes were successfully performed.
4. On November 16, a periodic RPM 10-Newton thruster maintenance activity was
performed; 10 of the 12 thrusters were "flushed" during the activity. The
P-thrusters were not flushed because they were used to perform science turn
(SITURN) activities on the same day. Spacecraft performance throughout the
activity was normal.
5. On November 16, the spacecraft performed a 13 degree SITURN. The purpose
of the SITURN was to maintain the spacecraft within plus or minus 10 degrees
of the sun at the current solar distance. Real-time commands were also sent to
change the downlink telemetry format back to the Low Rate Science (7.68 kbps)
from the Engineering High Rate 1200bps (automatically selected in the maneuver
PA) to collect a unique near-Earth magnetosphere data.
6. On November 16, the Earth vector and Earth stars were updated to the
spacecraft's current attitude. This change implements the attitude maintenance
strategy required in the case of an AACS (Attitude and Articulation Control
Subsystem) POR (Power-On Reset). If a fault occurs which terminates the
currently executing sequence, the spacecraft will maintain its current
attitude.
7. On November 17, the Relay Radio Hardware (RRH) oscillators No. 1 and 2
were powered on in preparation for the Probe Mission Sequence Test (MST)
scheduled for November 20, 1992. Shortly after turn on the oscillator
temperatures increased to expected values.
8. On November 18, real-time commands were sent to turn the Ultraviolet
Spectrometer (UVS) instrument on, load and readout the UVS memory, and start
the UVS microprocessor. Three memory readouts of the UVS load were completed
and verified prior to turning the UVS microprocessor on. The instrument was
then configured to a nominal state with the master high voltage disabled,
G-channel selected, and the grating stepping. The UVS is now properly
configured for the start of EE-9 (Earth-Earth 9 sequence). The UVS
supplemental heater was turned off to complete the activity.
9. On November 19, real-time commands were sent to increase the telemetry
rate from 7.68 kbps to 28.8 kbps in preparation for the Probe Mission Sequence
Test (MST) on the following day. Additionally, Delayed Action Commands (DACs)
were sent to turn ranging off and two-way non-coherent (TWNC) on prior to the
MST and reconfigure to ranging on and TWNC off after the MST completes. These
actions were taken to optimize telecommunications performance during the Probe
MST.
10. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 15DN to 17DN and now reads 15DN (3.5 volts).
The DC measurement has ranged from 134DN (15.7 volts) to 142DN (16.7 volts)
and now reads 142DN (16.7 volts). These measurement variations are consistent
with the model developed by the AC/DC special anomaly team.
11. The Spacecraft status as of November 19, 1992, is as follows:
a) System Power Margin - 80 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 6 degree
off-sun (leading) and 16 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-28.8kbps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- PWS, PLS, UVS, EPD, MAG, HIC and DDS are powered on
i) Probe/RRH - RRH oscillators powered on, temperatures
within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 260 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-12 Final Profile Design Product was approved by the Project on
November 13. This sequence covers spacecraft activities from January 20, 1993
to January 23, 1993 and from February 8, 1993 to April 12, 1993.
2. The EE-11 Preliminary Sequence and Command Generation products were
approved by the Project on November 17. This sequence covers spacecraft
activities from December 7 to December 28, 1992 including the Earth 2 closest
approach on December 8.
3. The EE-9 Final Sequence and Command Generation package was approved for
transmission by the Project on November 19, 1992. This sequence covers
spacecraft activities from November 23, 1992 to December 5, 1992. The
sequence is scheduled to be sent to the spacecraft on November 21.
GDS (Ground Data Systems):
1. A second SPC-60 (Madrid Signal Processing Center) Telemetry Data Flow test
was conducted on Monday, November 16. The test was successful in establishing
a configuration for the Probe checkouts. This configuration utilized two
Type A TPA's (Telemetry Processing Assemblies) in parallel, one configured to
the 56K full duplex line and one configured to the 224kbps Simplex line, with
Area Routing Assembly (ARA-1) as Prime and ARA-2 as backup. The only drop-outs
with this configuration were associated with "line hits" and were recoverable
on ARA ODR (Original Data Recording) replays. The test also successfully
demonstrated the configuration to be used to support 134.4 kbps High Rate
science at Earth 2. As a result of an excellent effort by DSN (Deep Space
Network) and SPC-60 personnel, data dropouts have been minimal this week.
TRAJECTORY
As of noon Thursday, November 19, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 14,931,800 km (.10 AU)
Distance from Sun 161,989,800 km (1.08 AU)
Heliocentric Speed 118,300 km per hour
Distance from Jupiter 912,828,500 km
Round Trip Light Time 1 minute, 38 seconds
SPECIAL TOPIC
1. As of November 19, 1992, a total of 8684 real-time commands have been
transmitted to Galileo since Launch. Of these, 3660 were initiated in the
sequence design process and 5024 initiated in the real-time command process.
In the past week, 35 real time commands were transmitted: none were initiated
in the sequence design process and 35 initiated in the real time command
process. Major command activities this week included commands to reconfigure
the downlink telemetry data rate to 7.68 kbps, turn the UVS instrument on and
configure it for science data collection, turn the UVS supplemental heater off,
switch the telemetry rate to 28.8 kbps, and configure ranging and the TWNC for
the probe MST.
2. A training rehearsal for the GOPEX experiment operations was successfully
completed November 18th. The rehearsal was supported by elements of the
Galileo Flight Team (MCT, NAV, and SDT), DSN Ops Team and GOPEX operations
Team at Table Mountain Observatory (TMO) and Kirtland AFB.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Learn to recognize the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | inconsequential, then
|_____|/ |_|/ |_____|/ | ignore it.
Article: 2510
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/23/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 24 Nov 1992 05:22:31 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 23, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 28.8 Kbps (28,800 bits/second).
Over the weekend, the EE-9 (Earth-Earth 9) sequence memory load was
uplinked to the spacecraft on Saturday, along with performing delta DOR
(Differential One-way Ranging) passes over DSS-14/43 (Goldstone/Canberra)
and DSS-14/63 (Goldstone/Madrid). DACs (Delayed Action Commands) were also
sent on Saturday to perform wobble compensation on Monday in preparation
for the Earth 2 encounter. Continuous tracking was scheduled over DSS-14,
DSS-43 and DSS-63.
Today, November 23, 1992, the Gaspra data playbacks are scheduled along
with turning on the SSI (Solid State Imaging Camera) and NIMS (Near Infrared
Mapping Spectrometer) instruments, performing science instrument calibrations,
and updating AACS (Attitude and Articulation Control Subsystem) bright body
avoidance parameters. Continuous tracking is scheduled over DSS-14, DSS-43
and DSS-63.
Tomorrow, Gaspra data playbacks are scheduled along with science
instrument calibrations. Continuous tracking is scheduled over DSS-14,
DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Learn to recognize the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | inconsequential, then
|_____|/ |_|/ |_____|/ | ignore it.
Article: 2517
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/24/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 25 Nov 1992 03:30:40 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 24, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 28.8 Kbps (28,800 bits/second).
Yesterday, the Gaspra data playbacks were performed, the SSI (Solid State
Imaging Camera) and NIMS (Near Infrared Mapping Spectrometer) instruments were
turned on, science instrument calibrations were performed, and spacecraft
wobble compenstation and AACS (Attitude and Articulation Control Subsystem)
bright body avoidance parameters updates were performed. Continuous tracking
was scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43 (Canberra
70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, November 24, 1992, Gaspra data playbacks are scheduled along with
science instrument calibration and characterization activities. Continuous
tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, Gaspra data playbacks are scheduled along with routine RPM
(Retro-Propulsion Module) 10-Newton thruster flushing maintainence and science
instrument calibration characterization activities. Continuous tracking is
scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Learn to recognize the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | inconsequential, then
|_____|/ |_|/ |_____|/ | ignore it.
Article: 29013
From: higgins@fnalf.fnal.gov (Bill Higgins-- Beam Jockey)
Newsgroups: sci.space,sci.astro
Subject: New Gaspra data, Earth pix (was Re: Galileo Update - 11/24/92)
Date: 25 Nov 92 01:38:39 GMT
Organization: Fermi National Accelerator Laboratory
In article <1992Nov24.193106.3026@news.arc.nasa.gov>,
baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:
> GALILEO STATUS REPORT
> November 24, 1992
> Yesterday, the Gaspra data playbacks were performed, [...]
> Today, November 24, 1992, Gaspra data playbacks are scheduled [...]
> Tomorrow, Gaspra data playbacks are scheduled along with [...]
Oh, boy, oh boy. I know what should be in there. One low-res
six-color image, and a number of others, showing Gaspra fuzzier than
we've seen it before, but at least some detail on the "back side" we
haven't seen yet. Full infrared imaging spectrometer data, good for
composition analysis and quantitative thermal modeling. Other data
from the Gaspra encounter last year that have been sitting quietly on
Galileo's tape recorder.
Wonder when we'll get to see any of these data?
Earth encounter two coming up on 8 December. Hope Galileo doesn't
smack into Toutatis. We should see more pix of Earth and Moon on TV
in the days afterward, maybe including the movie of their motion
(don't get excited, the Moon will only be a few dozen pixels across;
and it's real dark compared to the Earth, so it will be hard to
capture them in the same scene without overexposing Earth or
underexposing the Moon).
Then in late December and early January, more thermal cycling of the
high-gain antenna mast, combined with "hammering" from the mechanism
that attempts to open the HGA. Maybe the ribs will pop.
Now that I think about it, I suppose they'll probably show us the new
Gaspra images at the post-encounter press conference. Better alert my
pal to fire up his satellite dish and VCR...
Bill Higgins, Beam Jockey |
Fermi National Accelerator Laboratory | "Get the dinosaurs in, Martha,
Bitnet: HIGGINS@FNAL.BITNET | they're predicting comets."
Internet: HIGGINS@FNAL.FNAL.GOV | --Dr. Barry D. Gehm
SPAN/Hepnet: 43011::HIGGINS |
|
| 560.682 | One last trip to Earth | VERGA::KLAES | I, Robot | Wed Dec 02 1992 14:58 | 84 |
| Article: 2833
From: clarinews@clarinet.com (UPI)
Newsgroups: clari.tw.space,clari.local.texas,clari.news.gov.agency
Subject: Space probe to pass Earth
Date: Tue, 1 Dec 92 17:15:29 PST
PASADENA, Calif. (UPI) -- NASA's Galileo space probe will zip past
Earth and the Moon next week to use the planet's gravity to fling it
toward an exploration of Jupiter beginning in three years, officials
said Tuesday.
``We are now just one week from the Earth-II flyby, the gravity
assist, that will send Galileo to Jupiter,'' said project manager
William O'Neil during a briefing at NASA's Jet Propulsion Laboratory.
Galileo will pass within about 68,000 miles of Earth's Moon at 10:58
p.m. EST Dec. 7 and pass within 190 miles of Earth at 10:09 a.m. EST the
next day, he said. The pass will increase the probe's speed by 8,280
mph, whipping it out toward the asteroid belt between Mars and Jupiter
at about 87,190 mph.
Scientists plan to use the pass by the atomic-powered, $1.4 billion
spacecraft to calibrate the probe's instruments by using the various
sensors and cameras to study and photograph the Earth and Moon.
Beginning eight days after passing Earth, the probe will take a
series of color images of both the Earth and Moon that will be compiled
into a short film that will be released Dec. 22, he said.
``When we look back and image the Earth we'll be able to form this
unprecedented view,'' O'Neil said. ``For 14 hours, we'll be able to
construct effectively a movie of the Moon traversing the foreground of
the Earth. We're very much looking forward to this.''
Named after the Italian astronomer credited with discovering
Jupiter's four brightest moons, the 5,990-pound Galileo is the most
sophisticated interplanetary spacecraft ever built, equipped with a
battery of 10 state-of-the-art instruments.
Galileo was launched from the space shuttle Atlantis on Oct. 18,
1989, kicking off a six-year, three-planet celestial billiard shot
requiring the probe to sail once past Venus and twice past Earth for
velocity-boosting gravity-assist flybys required to fling the probe on
to distant Jupiter.
The ringed planet Jupiter, lord of a miniature solar system of 16
whirling moons, is the largest planet in orbit around the sun, a
violent, hostile world of searing lightning, centuries-old storms and
belts of deadly radiation.
The spacecraft zoomed past Venus and Earth in 1990, gaining enough
speed during the second flyby to reach the asteroid belt between Mars
and Jupiter. After passing within 1,000 miles of the asteroid Gaspra
Oct. 29, Galileo fell back into the inner solar system for a second
flyby of Earth.
After passing Earth, Galileo will fly within 600 miles of the
asteroid Ida on Aug. 28, 1993. Finally, on Dec. 7, 1995, Galileo will
flash past the volcanic moon Io at an altitude of just 600 miles, using
the bizarre moon's gravity to help decelerate into the jovian system,
lining up on a trajectory that will carry it over the point where the
entry probe will hit the atmosphere of Jupiter.
If all goes well, the spacecraft will drop an instrumented probe
into Jupiter's stormy atmosphere before the mothership slips into orbit
around the giant planet in December 1995 for a planned 20-month tour.
Assuming it survives the hellish entry, its six instruments will
begin radioing data to the Galileo mothership high overhead for relay
back to scientists on Earth.
Sailing through a ballet of ever-changing orbits, Galileo's
electronic ears and eyes will study Jupiter's atmosphere, its whirling
moons and its space environment in exquisite detail, beaming back close-
up photographs 20 to 1,000 times better than the spectacular pictures
taken by the Voyager probes.
When it past Gaspra, Galileo snaped some 150 pictures to give
scientists their first close-up look at a relic of the solar system's birth.
Technicians, meanwhile, still hope to free the probe's jammed main
``high-gain'' antenna, which limits the speed at which the probe can
transmit data back to Earth.
|
| 560.683 | Wave bye bye | MAYDAY::ANDRADE | The sentinel (.)(.) | Tue Dec 08 1992 13:38 | 5 |
|
I guess no news is good news, Galileo's Earth-II closest aproach
happened about half hour ago. Hope it took a few good photos I
was smilling at the time (-;
|
| 560.684 | | FASDER::ASCOLARO | Anthony Edward, 5/5/92 | Tue Dec 08 1992 15:45 | 3 |
| With Galileo, no news is bad news. News would be that the HGA deploys.
Tony
|
| 560.685 | Galileo cruises by the earth | PRAGMA::GRIFFIN | Dave Griffin | Wed Dec 09 1992 12:12 | 44 |
| Paula Cleggett-Haleim
Headquarters, Washington, D.C. December 8, 1992
James H. Wilson
Jet Propulsion Laboratory, Pasadena Calif.
RELEASE: 92-217
NASA's Galileo spacecraft flew by the Earth this morning at 10:09 a.m.
EST at an altitude of 189 miles (304 kilometers) above the South Atlantic
Ocean, completing a 3- year gravity-assist program and setting a course to
reach Jupiter in December 1995.
This, the third gravity-assist for Galileo, added about 8,300 miles per
hour (13,300 kilometers per hour) to the spacecraft's speed in its solar orbit
and changed its direction slightly so that its elliptical orbit now will reach
to the orbit of Jupiter, about 480 million miles (780 million kilometers) from
the sun.
On its way to the Earth encounter the spacecraft flew about 68,000
miles (110,000 kilometers) north of the moon at 10:58 p.m. EST last night.
Departing from the Earth in a slightly southerly direction, it again crosses
the moon's orbit at about 9:15 p.m. EST today.
The Galileo flight team at NASA's Jet Propulsion Laboratory, Pasadena,
Calif., programmed the spacecraft to measure the near-Earth environment and
observe Earth and the moon during this flyby. Scientists will obtain a great
many images and spectral scans of the northern regions of the moon and of
various areas on Earth over a period lasting several days. This provides
scientific data from new perspectives in some cases and helps the scientists
calibrate their instruments for the Jupiter orbital mission planned for 1995-
1997.
The Galileo orbiter will fly ten different elliptical orbits of Jupiter
with close passes by each of the major satellites and extended observations of
the planet and its magnetosphere. Galileo's atmospheric probe, which will
descend into Jupiter's atmosphere on Dec. 7, 1995 to observe that environment
for the first time, is being checked out during the near-Earth flight.
The Galileo Project is managed for NASA by the Jet Propulsion Laboratory.
The atmospheric probe is provided by Hughes Aircraft Company under contract to
NASA Ames Research Center, Mountain View, Calif.
|
| 560.686 | HGA: No news is no news | KACIE::DEUFEL | Daniel Allen Deufel | Thu Dec 10 1992 14:25 | 10 |
| I seem to recall reading that the upload of the hammering program had
been done but the hammering wasn't scheduled to begin for another
couple of weeks (December 28 sticks in my mind). No attempt was made to
open the HGA during the E-II GA.
So, in this case, there is nothing to report.
Cheers,
-Abdul-
|
| 560.687 | Comments from JPL members | VERGA::KLAES | I, Robot | Thu Dec 10 1992 17:25 | 99 |
| Article: 1485
From: clarinews@clarinet.com (UPI)
Newsgroups: clari.tw.space,clari.local.texas,clari.news.gov.agency
Subject: Galileo space probe passes Earth
Date: Tue, 8 Dec 92 13:59:58 PST
PASADENA, Calif. (UPI) -- The Galileo space probe flashed
past Earth Tuesday, zipping within 189 miles of the southern Atlantic
Ocean as the ``spunky'' craft used the planet's gravity to fling it
toward distant Jupiter.
Skirting closest to Earth at 10:09 a.m. EST, the encounter adjusted
the probe's direction and boosted Galileo's speed by 8,280 mph, whipping
it out on the final leg of its circuitous six-year Jovian journey at
87,190 mph.
``How sweet it is. We are on the way to Jupiter,'' said project
manager William J. O'Neil at a briefing at NASA's Jet Propulsion Laboratory.
Other than a balky antenna, the atomic powered, $1.4 billion craft
was healthy despite having traveled some 1.5 billion miles, collecting
invaluable data along the way, officials said.
``We already owe a lot to this spunky spacecraft for the new science
its given us in this tour so far in the inner solar system,'' said
NASA's Wesley Huntress Jr.
Scientists capitalized on Tuesday's encounter with Earth by using
Galileo's various sensors and cameras to calibrate the instruments by
studying and photographing the Earth and moon.
Before passing Earth, Galileo flew within 68,000 miles of the
moon at 10:58 p.m. Monday, providing researchers with the oportunity
to photograph the moon's north pole for the first time.
Eight days after passing Earth, the probe will take a series of color
images of both the Earth and moon that will be compiled into a short
film that will be released Dec. 22.
The encounter was emotional for many scientists, some of whom have
been working for decades on the project. Mission Director Neal Ausman
stepped outside Monday night to glance at the moon at the moment Galileo
sped by.
``It was a really emotional experience for me, still is,'' Ausman
said. ``I've devoted 15 years of my life to this project. I was struck
at that moment by the fact that in less than 12 hours our spacecraft would
finally be on its way to Jupiter. So last night I said a quiet goodbye.''
Named after the Italian astronomer credited with discovering
Jupiter's four brightest moons, the 5,990-pound Galileo is the most
sophisticated interplanetary spacecraft ever built, equipped with a
battery of 10 state-of-the-art instruments.
Galileo was launched from the space shuttle Atlantis on Oct. 18,
1989, kicking off a six-year, three-planet celestial billiard shot
requiring the probe to sail once past Venus and twice past Earth for
velocity-boosting gravity-assist flybys required to propel the probe on
to distant Jupiter.
The ringed planet Jupiter, lord of a miniature solar system of 16
whirling moons, is the largest planet in orbit around the sun, a
violent, hostile world of searing lightning, centuries-old storms and
belts of deadly radiation.
The spacecraft zoomed past Venus and Earth in 1990, gaining enough
speed during the second flyby to reach the asteroid belt between Mars
and Jupiter. After passing within 1,000 miles of the asteroid Gaspra
Oct. 29, Galileo fell back into the inner solar system for a second
flyby of Earth.
After passing Earth, Galileo will fly within 600 miles of the
asteroid Ida on Aug. 28, 1993. Finally, on Dec. 7, 1995, Galileo will
flash past the volcanic moon Io at an altitude of just 600 miles, using
the bizarre moon's gravity to help decelerate into the Jupiet's system,
lining up on a trajectory that will carry it over the point where the
entry probe will hit the planet's atmosphere.
If all goes well, the spacecraft will drop an instrumented probe
into Jupiter's stormy atmosphere before the mothership slips into orbit
around the giant planet in December 1995 for a planned 20-month tour.
Assuming it survives the hellish entry, its six instruments will
begin radioing data to the Galileo mothership high overhead for relay
back to scientists on Earth.
Sailing through a ballet of ever-changing orbits, Galileo's
electronic ears and eyes will study Jupiter's atmosphere, its whirling
moons and its space environment in exquisite detail, beaming back close-
up photographs 20 to 1,000 times better than the spectacular pictures
taken by the Voyager probes.
When it past Gaspra, Galileo snaped some 150 pictures to give
scientists their first close-up look at a relic of the solar system's birth.
Technicians, meanwhile, still hope to free the probe's jammed main
``high-gain'' antenna. The snag limits the speed at which the probe can
transmit data back to Earth.
|
| 560.688 | | AUSSIE::GARSON | | Thu Dec 10 1992 20:15 | 6 |
| re .687
> The ringed planet Jupiter, lord of a miniature solar system of 16
>whirling moons
Does Jupiter really have rings or do they mean bands?
|
| 560.689 | | HELIX::MAIEWSKI | | Thu Dec 10 1992 20:25 | 10 |
| No, Jupiter, Uranus and Neptune all have rings although no where near as
dramatic as the ones around Saturn. It is almost impossible to see them when
the sun is at your back which is the only way we ever see those planets from
earth.
When the rings were back lit from the perspective of the Voyagers flying
past, then they became visible much as dust on your windshield becomes visible
when back lit from headlights of on coming cars.
George
|
| 560.690 | | FASDER::ASCOLARO | Anthony Edward, 5/5/92 | Thu Dec 10 1992 23:58 | 4 |
| George is exactly right, however, considering it is a, what AP report,
I think they probably mean bands.
Tony
|
| 560.691 | Updates - November 25 to December 10 | VERGA::KLAES | I, Robot | Fri Dec 11 1992 15:29 | 928 |
| Article: 2527
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/25/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 26 Nov 1992 14:16:46 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
November 20 - 25, 1992
SPACECRAFT
1. On November 20, delta Differenced One-Way Range (DOR) passes were
performed over DSS-14/63 (Goldstone/Madrid) and DSS-14/43 (Goldstone/Canberra).
Initial results indicate that both delta DOR passes were successfully
performed.
2. On November 20, a routine sun vector update was performed. This sun
vector is valid through December 3, 1992.
3. On November 20, the Probe Mission Sequence Test (MST) was performed. The
MST throughly tested the actual Probe mission, including the operation of the
data and command processor, and all of the Probe scientific instruments
including the valve actuations of the Neutral Mass Spectrometer (NMS). Initial
results indicate that the Probe and the scientific instruments are operating
nominally. Detailed analysis and test results from Ames and Hughes are
forthcoming.
During the MST, the heaters on the scan platform were cycled off for
several hours to support power requirements for the test. Due to thermal
isolation between the Photopolarimeter-Radiometer (PPR) and the scan platform
structure, the PPR temperatures continued to decrease after the scan platform
heaters were turned back on, violating the GLL-3-210 non-operating Limit of
minus 25 degrees C. No real-time action was taken because the scan platform
was warming and the PPR temperatures were predicted to raise. Analysis of
this anomaly is continuing.
4. On November 21 and 22, delta DOR passes were performed over DSS-14/43 and
DSS-14/63. Initial results indicate that both delta DOR passes were
successfully performed.
5. On November 21, the EE-9 (Earth-Earth 9) sequence memory Load was uplinked
to the spacecraft without incident. This sequence covers spacecraft activities
from November 23, 1992 to December 5, 1992 which is the approach phase of
the Earth 2 encounter.
6. On November 21, Delayed Action Commands (DACs) were sent to perform wobble
compensation on November 23 in preparation for the Earth 2 encounter. The
Linear Boom Actuators (LBAs) were moved to decrease the current spacecraft
wobble from 1.2 milliradians to within 0.5 milliradians to support scan
platform pointing requirements for science data gathering. Initial results
from the wobble ID performed on November 23 indicates the spacecraft wobble is
now approximately 0.35 milliradians.
7. On November 23, the Solid State Imaging (SSI) instrument was turned on and
its memory Loaded nominally along with turning the SSI replacement heater off.
Also, the Near Infrared Mapping Spectrometer (NIMS) instrument was turned on
and its associated replacement heater and shield heater turned off. Initial
indications are that both instrument are operating nominally.
8. On November 23, all of the Gaspra data was played back over DSS-63 (Madrid
70 meter antenna). Initial results indicate that all of the data was received
on the ground. Additional playbacks are scheduled on November 24 and
November 25.
9. On November 23 and 25, No-Op commands were sent to reset the command Loss
timer to 96 hours, its planned value for this mission phase.
10. On November 23, real-time commands were sent to update the AACS (Attitude
and Articulation Control Subsystem) Bright Body Avoidance (BBA) parameters in
preparation for the Earth-2 encounter. The commands were executed on the
spacecraft without incident.
11. On November 23, a Plasma Wave (PWS) calibration was performed. Its
purpose was to determine the sensitivity of the PWS search coil as a function
of frequency with a known input signal. Initial results indicate the PWS
calibration executed nominally. Detailed analyses is in progress.
12. On November 23 and 24, Magnetometer (MAG) scan platform interference
calibrations were performed. The calibration characterized the scan platform
interference at five different cone angles.
13. On November 24, the MAG external Calibration Coil (CALCOIL) was performed
to determine the alignment of the science boom in the remaining four instrument
modes which were not done during the Earth 1 encounter. The CALCOIL was
performed nominally. Analysis of the results are in progress.
14. On November 24, an Energetic Particle Detector (EPD) calibration was
performed which used both an electronic calibration signal (generated within
the instrument) and a radioactive source (mounted on the instrument). The
test was performed nominally and data analysis is in progress.
15. On November 24 and 25, a Plasma Wave (PWS)/Ultraviolet Spectrometer (UVS)
interference map was performed to determine the PWS search coil response to
UVS grating stepping as a function of their relative orientation with respect
to the spacecraft. Simultaneously, a UV map of the anti-sun hemisphere
measuring background Lyman-alpha was collected. The test was performed
without incident and analysis is in progress.
16. On November 25, a Photometric Calibration Target (PCT) calibration was
performed which provided SSI flat field and noise removal information along
with inter-instrument comparison measurements. The Photopolarimeter-Radiometer
(PPR) instrument was turned on in support of the PCT. Analysis of the data is
in progress.
17. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 15DN to 17DN and now reads 17DN (3.9 volts). The
DC measurement has ranged from 133 DN (15.6 volts) to 144 DN (16.9 volts)
and now reads 137 DN (16.1 volts). These measurement variations are
consistent with the model developed by the AC/DC special anomaly team.
18. The Spacecraft status as of November 25, 1992, is as follows:
a) System Power Margin - 73 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/Star Scanner
d) Spacecraft Attitude is approximately 6 degree off
sun (lagging) and 16 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna - 67.2 kbps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science - PWS, PLS, UVS, EPD, MAG, SSI,
HIC, NIMS, and DDS are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 96 hours
Time to initiation - 89 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Trajectory Correction Maneuver (TCM-17) design package was approved
by the Project on November 24, 1992. TCM-17 is a one portion maneuver
scheduled to execute on November 28, consisting of one axial and one lateral
segment. The estimated total delta velocity for TCM-17 is 0.03 m/sec.
TRAJECTORY
As of noon Thursday, November 25, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 10,073,900 km (.07 AU)
Distance from Sun 156,958,200 km (1.05 AU)
Heliocentric Speed 121,200 km per hour
Distance from Jupiter 898,004,200 km
Round Trip Light Time 1 minutes, 6 seconds
SPECIAL TOPIC
1. As of November 25, 1992, a total of 8699 real-time commands have been
transmitted to Galileo since Launch. Of these, 3675 were initiated in the
sequence design process and 5024 initiated in the real-time command process.
In the past week, 15 real time commands were transmitted: 15 were initiated in
the sequence design process and none initiated in the real time command
process. Major command activities this week included commands to uplink the
EE-9 stored sequence memory load, perform wobble compensation, update the AACS
Bright Body Avoidance (BBA) parameters, and to reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Learn to recognize the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | inconsequential, then
|_____|/ |_|/ |_____|/ | ignore it.
Article: 2547
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 11/30/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 1 Dec 1992 06:14:40 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
November 30, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 115.2 Kbps (115,200 bits/second).
Over the weekend, TCM-17 (Trajectory Correction Maneuver #17) executed
normally on Saturday. Real-time commands to update system fault protection
parameters were transmitted on Saturday, as planned. Near continuous tracking
was scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43 (Canberra
70 meter antenna), DSS-61 (Madrid 34 meter antenna) and DSS-63 (Madrid 70
meter antenna).
Today, November 30, 1992, a SITURN of approxiamately 11 degrees is
scheduled along with engineering and science instrument calibration and
characterization activities. The RRH (Relay Radio Hardware) oscillators are
scheduled to be turned on for preparation of the Probe systems functional test
on Wednesday, December 2. Continuous tracking is scheduled over DSS-14,
DSS-43 and DSS-63.
Tomorrow, a sun vector update is scheduled along with continuous science
instrument calibration characterization activities. Continuous tracking will
continue over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Learn to recognize the
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | inconsequential, then
|_____|/ |_|/ |_____|/ | ignore it.
Article: 2555
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/01/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 2 Dec 1992 06:41:36 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 1, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 115.2 Kbps (115,200 bits/second).
Yesterday, a SITURN of approximately 11 degrees was performed along with
engineering and science instrument calibration characterization activities.
The RRH (Relay Radio Hardware) oscillators were turned on for preparation of
the Probe systems functional test on Wednesday, December 2. Continuous
tracking was scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43
(Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, December 1, 1992, a sun vector update is scheduled along with
continuous science instrument calibration characterization activities.
DAC's (Delayed Action Commands) are being sent to authorize telecommuncations
performance for the Probe systems functional test. Continuous tracking is
scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, the Probe system functional test is scheduled. Science
instrument calibration tests will continue. Continuous tracking will continue
over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2558
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/02/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 3 Dec 1992 03:28:14 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 2, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 115.2 Kbps (115,200 bits/second).
Yesterday, a sun vector update was performed along with continued science
instrument calibration characterization activities. DAC's (Delayed Action
Commands) were also sent to authorize telecommuncations performance for the
Probe systems functional test. Continuous tracking was scheduled over
DSS-14 (Goldstone 70 meter antenan), DSS-43 (Canberra 70 meter antenna)
and DSS-63 (Madrid 70 meter antenna).
Today, December 2, 1992, the Probe system functional test is scheduled.
The telemetry switch to 28.8 Kbps (28,800 bit/second) is scheduled for the
test, after which it will go back to 115.2 Kbps. Science instrument
calibration characterization activities will continue. Continuous tracking is
scheduled over over DSS-14, DSS-43 and DSS-63.
Tomorrow, science instrument calibration and characterization activities
will continue. Continuous tracking is scheduled over DSS-14, DSS-43 and
DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2560
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/03/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 4 Dec 1992 06:39:35 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 3, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 115.2 Kbps (115,200 bits/second).
Yesterday, the Probe system functional test was performed, as expected.
The telemetry rate switch to 28.8 Kbps (28,800 bit/second) was scheduled for
the test. Subsequently, the telemetry rate was switched back to 115.2 Kbps.
Science instrument calibration characterization activities continued.
Continuous tracking was scheduled over over DSS-14 (Goldstone 70 meter
antenna), DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter
antenna).
Today, December 3, 1992, science instrument calibration and
characterization activities are continuing. Continuous tracking is scheduled
over DSS-14, DSS-43 and DSS-63.
Tomorrow, part 1 of the EE-11 Earth encounter sequence memory load is
scheduled to be uplinked to the spacecraft. The remainder of the Earth
encounter sequence will be uplinked on December 7. Real-time commands are
scheduled to update as control parameters to enable Bright Body fault
protection and update sun dependent algorithms. Science instrument calibration
and characterization activities are continuing. Continuous tracking is
scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2565
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/04/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 5 Dec 1992 02:22:24 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
November 26 - December 3, 1992
SPACECRAFT
1. During the reporting period, numerous science instrument
calibration/characterization activities were performed to take advantage of
the high telemetry data rates while close to the Earth. Activities included
Magnetometer (MAG) external calibration coil, Scan Actuator Subassembly (SAS)
friction test, Near Infrared Mapping Spectrometer (NIMS) and Ultraviolet
Spectrometer (UVS) star calibrations, MAG slew test, MAG gradiometer tests,
Radiometric calibration, Solid State Imaging (SSI) star calibrations, and a
MAG scan platform interference calibration. All calibration/characterization
activities were performed nominally and data analysis is in progress.
2. On November 26, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
maintenance activity was performed; 10 of the 12 thrusters were "flushed"
during the activity. The P-thrusters were not flushed because they were used
to perform SITURN activities on November 30. Spacecraft performance throughout
the activity was normal.
3. On November 27, Trajectory Correction Maneuver, TCM-17, memory load was
uplinked to the spacecraft without incident. The Energetic Particle Detector
(EPD) instrument was stepped to Sector O which is the predicted least
contaminated position in preparation for the execution of TCM-17 and returned
to Sector 4 after completion of the maneuver.
4. On November 28, real-time commands were sent to change the System Fault
Protection (SFP) AACS-INIT (Attitude and Articulation Control Subsystem)
pointing slot from the Earth to the Sun prior to the TCM-17 activities. This
change allows the spacecraft to return to a sun-pointed attitude if an AACS
Power-on Reset (POR) occurs.
5. On November 28, TCM-17 was performed on the spacecraft. The maneuver
consisted of one axial and one lateral segment imparting a predicted total
delta velocity of 0.03 m/sec. This maneuver was executed at 7.68 kbps
(7680 bits/second) with the spacecraft pointed approximately 8 degrees off
the sun.
The spacecraftUs performance throughout the activity was nominal. All
RPM pressures and temperatures and attitude control indicators were near
predicted levels. After the axial and lateral burn segments, the sequence
planned spin corrections and pointing corrections were not needed.
Preliminary radio navigation data indicates a 0.7 percent overburn for the
axial segment and a 0.4 percent overburn for the lateral segment.
6. On November 28, the Plasma Detector (PLS) regulator temperature monitor
exceeded its preset limit of 35 degrees C by 0.33 degree. This initiated an
internal PLS alarm which automatically requested the CDS (Command Data
Subsystem - Galileo's main computer) to turn off the PLS supplemental heater.
The heater was already off to permit Earth science data collection and remain
within safe thermal limits. After consultation with the PLS science team, it
was determined that the instrument was thermally safe even though the limit
was exceeded. PLS instrument temperature monitoring is continuing.
7. On November 30 and December 1, 2, and 3rd, NO-OP commands were sent to
reset the command loss timer to 72 hours, its planned value during this
mission phase.
8. On November 30, the spacecraft performed a 11.5 degree SITURN. The
purpose of the SITURN was to maintain the spacecraft within plus or minus 10
degrees of the sun at the current solar distance.
9. On November 30, the Relay Radio Hardware (RRH) oscillators No. 1 and 2
were powered on in preparation for the Probe Abbreviated System Functional Test
(ASFT) scheduled for December 2, 1992. Shortly after turn on the oscillator
temperatures increased to expected values. Also, on December 1, Delayed Action
Commands (DACs) were sent to optimize the telecommunications performance for
the Probe ASFT.
10. On December 1, a routine sun vector update was performed. This sun vector
is valid through December 6, 1992.
11. On December 2, the Probe Abbreviated System Functional Test (ASFT) was
performed which consisted of a standard power up and power down with an
11 minute 54 second test to check the battery voltages and to pump out any
unwanted argon gas in the Neutral Mass Spectrometer (NMS) instrument. The
ASFT sequence was performed nominally. Detailed analysis and test results
from Ames and Hughes are forthcoming.
12. On December 3, real-time commands were sent to reconfigure the Energetic
Particle Detector (EPD) Composition Measurement System (CMS) telescope to its
original pre-calibration state in preparation for the Earth 2 encounter.
13. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 16DN to 17DN and now reads 17DN (3.9 volts).
The DC measurement has ranged from 138DN (16.2 volts) to 148DN (17.4 volts)
and now reads 145DN (17.1 volts). These measurement variations are consistent
with the model developed by the AC/DC special anomaly team.
14. The Spacecraft status as of December 3, 1992, is as follows:
a) System Power Margin - 68 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 1 degree
off-sun (lagging) and 28 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna-115.2kbps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- PWS, PLS, UVS, EPD, MAG, SSI, PPR,
NIMS, HIC and DDS are powered on
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 72 hours
Time To Initiation - 70 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Dual Drive Actuator (DDA-5) sequence memory load was approved for
generation by the Project on December 1, 1992. This sequence covers High Gain
Antenna (HGA) motor hammering activities from December 28, 1992 through
January 19, 1993.
2. The EE-11 (Earth-Earth 11) Final Sequence and Command Generation package
was approved by the Project on December 1, 1992. This sequence covers
spacecraft activities from December 7, 1992 to December 28, 1992 and includes
the Earth 2 closest approach on December 8. Part 1 of the EE-11 sequence
memory load is scheduled to be uplinked on December 4, 1992, and Part 2 on
December 7, 1992.
TRAJECTORY
As of noon Thursday, December 3, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 3,838,200 km (.03 AU)
Distance from Sun 150,792,300 km (1.01 AU)
Heliocentric Speed 124,800 km per hour
Distance from Jupiter 877,097,100 km
Round Trip Light Time 0 minutes, 24 seconds
SPECIAL TOPIC
1. As of December 3, 1992, a total of 8712 real-time commands have been
transmitted to Galileo since Launch. Of these, 3681 were initiated in the
sequence design process and 5031 initiated in the real-time command process.
In the past week, 13 real time commands were transmitted: 6 were initiated in
the sequence design process and 7 initiated in the real time command process.
Major command activities this week included commands to uplink the TCM-17
stored sequence memory load, update SFP pointing slot, reset the command Loss
timer, turn ranging off, and reconfigure the EPD.
2. Training for the Earth 2 closest approach operations was successfully
completed with a "walkthrough" of the final SOE on December 1.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2578
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Earth-Moon Flyby Briefing Set For Dec. 8
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 8 Dec 1992 00:17:48 GMT
Paula Cleggett-Haleim
Headquarters, Washington, D.C. December 7, 1992
(Phone: 202/358-0883)
Jim Wilson
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
NOTE TO EDITORS: N92-105
GALILEO EARTH-MOON FLYBY BRIEFING SET FOR DEC. 8
Galileo officials will describe the Earth-Moon flyby at a
briefing on Tuesday, Dec. 8, at 1 p.m. EST. The briefing will
originate from NASA's Jet Propulsion Laboratory (JPL), Pasadena,
Calif. Reporters can participate from the NASA Headquarters
auditorium, 400 Maryland Ave., S.W., Washington, D.C.
NASA's Galileo spacecraft swings past Earth on Dec. 8 for its
last gravity assist on the way to Jupiter, with a closest approach to
Earth at 10:09 a.m. EST.
Project Manager William J. O'Neil and Mission Director Neal
Ausman will describe the flyby, mission plans and Galileo's status.
Project Scientist Torrence V. Johnson and other members of the science
team are expected to discuss ongoing Earth-Moon scientific activities
and present some of the earliest results.
Galileo is scheduled to continue observing Earth and Moon for a
week or more, and a preliminary science briefing at JPL is set for
Dec. 22 at 1 p.m. EST.
A program, called "Blue Room," will provide up-to-date
information on mission and science operations and present sample
images starting at 9:30 a.m. EST. The conference and some of the Blue
Room activity will be carried live on NASA Select television, Satcom
F2R, 72 degrees west longitude, Transponder 13, C-Band.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2579
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/07/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 8 Dec 1992 06:08:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 7, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 115.2 Kbps (115,200 bits/second).
Over the weekend, no spacecraft activity was scheduled.
Continuous tracking was scheduled over over DSS-12 (Goldstone 34 meter
antenna), DSS-14 (Goldstone 70 meter antenna), DSS-42 (Canberra 34 meter
antenna), DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter
antenna).
Today, December 7, 1992, part 2 of the EE-11 Earth encounter sequence
memory load is being uplinked. Moon closest approach will occur at
approximately 7:58 PM PST. The stored sequence controlled Sun vector update
is also scheduled. Continuous tracking is scheduled over DSS-12, DSS-14,
DSS-16 (Goldstone 26 meter antenna), DSS-42, DSS-43, DSS-61 (Madrid 34 meter
antenna) and DSS-63.
Tomorrow, Earth closest approach will occur at approximately 7:09 AM PST.
Real-time commands are scheduled to enable the Sun algorithms, set the Command
Loss Timer to 11 days, and update attitude control bright body vectors.
Near continuous tracking is scheduled over DSS-12, DSS-16, DSS-42, DSS-43,
DSS-46 (Canberra 26 meter antenna) and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2583
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Cruises By Earth
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 9 Dec 1992 03:18:07 GMT
Paula Cleggett-Haleim
Headquarters, Washington, D.C. December 8, 1992
(Phone: 202/358-0883)
James H. Wilson
Jet Propulsion Laboratory, Pasadena Calif.
(Phone: 818/354-5011)
RELEASE: 92-217
GALILEO CRUISES BY THE EARTH
NASA's Galileo spacecraft flew by the Earth this morning at 10:09
a.m. EST at an altitude of 189 miles (304 kilometers) above the South
Atlantic Ocean, completing a 3-year gravity-assist program and
setting a course to reach Jupiter in December 1995.
This, the third gravity-assist for Galileo, added about 8,300
miles per hour (13,300 kilometers per hour) to the spacecraft's speed
in its solar orbit and changed its direction slightly so that its
elliptical orbit now will reach to the orbit of Jupiter, about 480
million miles (780 million kilometers) from the sun.
On its way to the Earth encounter the spacecraft flew about
68,000 miles (110,000 kilometers) north of the moon at 10:58 p.m. EST
last night. Departing from the Earth in a slightly southerly direction,
it again crosses the moon's orbit at about 9:15 p.m. EST today.
The Galileo flight team at NASA's Jet Propulsion Laboratory,
Pasadena, Calif., programmed the spacecraft to measure the near-Earth
environment and observe Earth and the moon during this flyby.
Scientists will obtain a great many images and spectral scans of the
northern regions of the moon and of various areas on Earth over a
period lasting several days. This provides scientific data from new
perspectives in some cases and helps the scientists calibrate their
instruments for the Jupiter orbital mission planned for 1995-1997.
The Galileo orbiter will fly ten different elliptical orbits of
Jupiter with close passes by each of the major satellites and extended
observations of the planet and its magnetosphere. Galileo's
atmospheric probe, which will descend into Jupiter's atmosphere on
Dec. 7, 1995 to observe that environment for the first time, is being
checked out during the near-Earth flight.
The Galileo Project is managed for NASA by the Jet Propulsion
Laboratory. The atmospheric probe is provided by Hughes Aircraft
Company under contract to NASA Ames Research Center, Mountain View, Calif.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2614
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/08/92 (Earth Flyby)
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 9 Dec 1992 11:30:59 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
Earth Flyby
December 8, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 115.2 Kbps (115,200 bits/second).
Yesterday, part 2 of the EE-11 Earth encounter memory load sequence
was uplinked. Moon closest approach occurred at approximately 7:58 PM PST.
The stored sequence controlled Sun vector update was performed. Continuous
tracking was scheduled over DSS-12 (Goldstone 34 meter antenna), DSS-14
(Goldstone 70 meter antenna), DSS-16 (Goldstone 26 meter antenna), DSS-42
(Canberra 34 meter antenan), DSS-43 (Canberra 70 meter antenna), DSS-61
(Madrid 34 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, December 8, 1992, Earth closest approach occurred at approximately
7:09 AM PST. Real-time commands are being sent to enable the Sun algorithms,
set the Command Loss Timer to 11 days, and update attitude control bright body
vectors. Near continuous tracking is scheduled over DSS-12, DSS-16, DSS-42,
DSS-43, DSS-46 (Canberra 26 meter antenna) and DSS-63.
Tomorrow, Earth closest approach and SSI (Solid State Imaging camera)
zoom movie observations are continuing. A GOPEX (Galileo Optical
Communications Experiment from an Earth-based Xmitter) experiment is scheduled
to begin. Tracking is scheduled over DSS-14, DSS-43 and DSS-63.
[Below I've summarized some of the highlights of Galileo's 1992 Earth-Moon
encounter. Ron Baalke]
Dec 7 - Moon observations. Galileo will be passing three times closer
to the Moon than it did in its first Earth flyby two years ago.
It passed over the North Pole of the Moon at a distance of
110,288 km (68,530 miles). Observations include multi-spectral
coverage and mapping of the Moon, and searching for indications
of water at the North Pole.
Earth observations. Examinations of the dark side of the Earth
in search for lightning and aurorae for comparison with Venus
measurements and future Jupiter observations.
Dec 8 - Fields and particles observations of the Earth's magnetosphere
which will be taken over a period of 28 days. Data will be
correlated with those taken by other spacecraft such as Ulysses,
Geotail, IMP-8 and Mars Observer.
Closest approach to Earth over the South Atlantic at an
altitude of 304 km (189 miles).
Obtain multispectral SSI images of the Andes mountain range
shortly after closest approach. This area has been extensively
studied by Earth satellites which provides excellent "ground
truth" comparisons for the Galileo instruments.
Evaluate low light level imaging of the SSI camera by observing
the city lights on Hawaii before dawn. Also observed later
in the day will be the city lights, possible volcanic eruptions,
and lightning from tropical storms over southeast Asia and
Indonesia before dawn.
Detected and characterize the polar stratospheric clouds over
the Antarctic using the NIMS (Near Infrared Mapping Spectrometer).
These clouds are catalysts for the ozone destruction and will
be monitored for changes from the Galileo observations made in
1990.
Acquire SSI coverage of as much as possible of the land area
of the Earth. This will go on for 48 hours and the images will
be assembed to form a time-lapse zoom movie of the receding
Earth.
Dec 9 - GOPEX, an experiment to demonstrate the capability of a
deep space probe to receive and distinguish laser signal from
Earth. A laser will be pulsed at Galileo from the Table Mountain
Observatory near Los Angeles and from the Starfire Optical Range
in New Mexico, and the SSI camera will be shuttered while slewing
across the Earth resulting in a series of illuminated dots in
the image.
Continue acquiring SSI images for the zoom movie.
Dec 10 - Continue GOPEX experiment.
Continue acquiring SSI images for the zoom movie.
Observe Asteroid Toutatis 4179 using the EUV (Extreme
Ultraviolet Spectrometer) instrument.
Dec 11 - Continue GOPEX experiment.
Dec 12 - Continue GOPEX experiment.
Perihelion. Galileo reachest the closest point to the Sun
during this flyby at 0.98 AU.
Dec 14 - Continue GOPEX experiment.
Dec 15 - Continue GOPEX experiment.
Dec 16 - Continue GOPEX experiment.
Obtain periodic 3-filter SSI coverage of the Earth and Moon during
conjunction period, to produce color time-lapse movie sequence.
These images will be taken over a 14 hour period.
SSI Image Summary:
No. of Images
Moon (multi-spectral) 1067
Earth (multi-spectral) 3594
Conjunction Movie (3-color) 168
GOPEX (Green filter) 160
Navigation Images 102
Calibration Images 1722
-----
Total 6813
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2630
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/09/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 10 Dec 1992 03:40:01 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 9, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 115.2 Kbps (115,200 bits/second).
Yesterday, Earth closest approach occurred at approximately
7:09 AM PST. Real-time commands were sent to enable the Sun algorithms,
set the Command Loss Timer to 11 days, update attitude control bright body
vectors, and turn the EPD (Energetic Particles Detector) bias off. Near
continuous tracking was scheduled over DSS-12 (Goldstone 34 meter antenna),
DSS-16 (Goldstone 26 meter antenna), DSS-42 (Canberra 34 meter antenna),
DSS-43 (Canberra 70 meter antenna), DSS-46 (Canberra 26 meter antenna) and
DSS-63 (Madrid 70 meter antenna).
Today, December 9, 1992, Earth closest approach and SSI (Solid State
Imaging camera) zoom movie observations are continuing. The GOPEX (Galileo
Optical Communications Experiment from an Earth-based Xmitter) experiment has
begun. Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna),
DSS-43 and DSS-63.
Tomorrow, a SITURN of -11 degrees is scheduled along with the SSI zoom
movie observations. The GOPEX experiment will continue and is scheduled
through December 16. Continuous tracking is scheduled over DSS-14, DSS-43 and
DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2632
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Moon Image Available
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 10 Dec 1992 07:11:58 GMT
=======================
GALILEO MOON IMAGE
December 9, 1992
=======================
A Galileo image of the north pole of the Moon has been released and
is now available in GIF format (GIF89a). The image was scanned
in from a photograph, and is not the raw data. The caption file
accompanying the image is attached below, and it is also embedded
in the image. The Galileo image is available using anonymous ftp to:
ftp: ames.arc.nasa.gov (128.102.18.3)
user: anonymous
cd: pub/SPACE/GIF
files:
moonpole.gif
moonpole.txt (caption file)
-------------------------------------------------------------------
moonpole.txt
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
PHOTO CAPTION (TOP) P-41432
GLL-EM14
December 9, 1992
This view of the north polar region of the Moon was obtained by
Galileo's camera during the spacecraft's flyby of the Earth-Moon
system on December 7 and 8, 1992. The north pole is to the lower
right of the image. The view in the upper left is toward the horizon
across the volcanic lava plains of Mare Imbrium. The prominent crater
with the central peak is Pythagoras, an impact crater some 130
kilometers (80 miles) in diameter. The image was taken at a distance
of 121,000 kilometers (75,000 miles) from the Moon throught the violet
filter of Galileo's imaging system. According to the team scientists,
the viewing geometry provided by the spacecraft's pass over the north
pole and the low sun-angle illumination provide a unique opportunity
to assess the geologic relationships among the smooth plains, cratered
terrain and impact ejecta deposits in this region of the Moon. JPL
manages the Galileo Project for NASA's Office of Space Science and
Applications.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2638
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/10/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 11 Dec 1992 02:27:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 10, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 67.2 Kbps (67,200 bits/second).
Yesterday, Earth closest approach and SSI (Solid State Imaging camera)
zoom movie observations continued. The GOPEX (Galileo Optical Communications
Experiment from an Earth-based Xmitter) experiment began. Tracking was
scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43 (Canberra 70 meter
antenna) and DSS-63 (Madrid 70 meter antenna).
Today, December 10, 1992, a SITURN of -11 degrees is scheduled along
with the SSI zoom movie observations. The GOPEX experiment will continue and
is scheduled through December 16. Continuous tracking is scheduled over
DSS-14, DSS-43 and DSS-63.
Tomorrow, science instrument calibration characterization activities
are scheduled. Continuous tracking is scheduled over DSS-12 (Goldstone 34
meter antenna), DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
|
| 560.692 | Probe Passes Health Checks | PONIL::J_BUTLER | E pur, si muove... | Tue Dec 15 1992 18:33 | 139 |
|
*** // { Note: Video Animation Telecast info at end of text -jb-} // ***
Article 2672 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!caen!saimiri.primate.wisc.edu!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo's Atmospheric Probe Passes Health Checks
Message-ID: <1992Dec15.170413.6139@news.arc.nasa.gov>
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.3-4
Keywords: Galileo, Jupiter, Ames, JPL
Sender: news@elroy.jpl.nasa.gov (Usenet)
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Reply-To: baalke@kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Wed, 16 Dec 1992 01:01:52 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 117
Paula Cleggett-Haleim
Headquarters, Washington, D.C. December 15, 1992
(Phone: 202/358-0883)
Pete Waller
Ames Research Center, Mountain View, Calif.
(Phone: 415/604-3938)
RELEASE: 92-224
GALILEO'S ATMOSPHERIC PROBE PASSES HEALTH CHECKS
The Galileo spacecraft and its atmospheric probe are now
halfway on their complex trip to Jupiter, and the first full tests
since launch 3 years ago show that the probe is in good shape, say
NASA officials.
"We have, for the first time since launch 3 years ago, checked
out the entire probe spacecraft system and run it through a full
mission sequence," said Benny Chin, Probe Project Manager, NASA's
Ames Research Center, Mountain View, Calif.
"All systems working together, including the seven scientific
instruments, are functioning well and will meet mission
objectives," he said.
The probe is being carried over most of the half billion miles
to Jupiter by the Galileo orbiter. At 51,358,400 miles from the
planet, the probe will separate from the orbiter and fly on by
itself. This will occur on July 10, 1995, 5 months before arrival
at Jupiter.
The probe will make history's first entry into the atmosphere
of an outer planet on Dec. 7, 1995. It will slam into Jupiter's
atmosphere at 115,000 mph, fast enough to jet from Los Angeles to
New York in 90 seconds. Deceleration to about Mach 1 -- the speed
of sound -- will take just a few minutes, causing a buildup of heat
so intense it will be like flying through a nuclear explosion.
The Galileo probe then will plunge 400 miles through the
planet's brilliantly colored cloud layers into the hot, dense
atmosphere below -- making history's first direct measurements of
Jupiter. As it descends, the probe will gather scientific data
about the giant planet's swirling clouds, violent winds and star-
like composition, providing clues to the origin of the solar
system.
Health of the Galileo probe was checked in a mission sequence
test on Nov. 20, 1992, and a functions test on Dec. 2. Data
analysis since then has confirmed that all of the craft's systems
are in good condition. A suspected loss of battery power, for
example, did not occur. Battery voltages are at the levels of
launch day, Oct. 18, 1989.
Entry into Jupiter's atmosphere is the most hazardous in the
solar system because the planet's immense gravitational pull
creates tremendous speeds. At maximum deceleration, as the craft
slows from 115,000 mph to 100 mph, the probe will hurtle against a
force 350 times Earth's gravity.
Its incandescent shock wave will be as bright as the sun and
reach temperatures up to 28,000 degrees Fahrenheit. After entry,
the fore and aft heat shields of the deceleration module will be
shed by deploying a small pilot parachute and then a large main
chute, exposing the descent module to Jupiter's hydrogen/helium
atmosphere.
The probe's total weight is 747 pounds. The deceleration
module weighs 484 pounds. The inner descent module carries seven
scientific instruments, weighing 66 pounds.
"The tests show that all the instrument parameters are within
normal limits," said Ames' Dr. Richard Young, Probe Project
Scientist.
To make the first direct measurements of Jupiter, he said, the
probe carries an atmosphere structure instrument, a mass
spectrometer for atmosphere composition, a cloud instrument, an
energetic particle instrument, a lightning detector, a helium
detector and a radiometer to chart energy flow in the atmosphere.
Together, they will characterize Jupiter's ionosphere and its
atmosphere (composition, temperature, and density), measure wind
speeds, cloud characteristics, lightning, the important ratio of
helium to hydrogen and the atmosphere's energy balance.
"Because of its size, make-up of original solar system
material, and being the biggest of the 'gas giant' outer planets,
Jupiter is a scientific treasure trove," said Young. "On the
science side, everything is fine so far. We can't wait to get
there," he said.
As the probe passes through Jupiter's colored cloud layers,
its computer will receive information, process it and transmit the
coded signal to the Galileo orbiter, which will relay the data by
radio to Earth. The probe descent mission will last about 75
minutes. At this point, a combination of extreme heat, high
pressure and degraded battery power will silence the probe forever.
The probe project is managed by the Ames Research Center. The
overall Galileo mission is managed by NASA's Jet Propulsion
Laboratory, Pasadena, Calif.
- end -
NOTE TO EDITORS: Dramatic mission animation, with new segments on
Jupiter's deep atmosphere will be telecast via NASA-Select on
Tuesday, Dec. 15, 1 p.m. EST and repeated at other times during the
day. This will be carried on Satcom F-2R, Transponder 13, 72
degrees west longitude, 3960 MegaHertz; audio 6.8 MHz, vertical
polarization.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in you life.
|
| 560.693 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Tue Dec 15 1992 19:57 | 4 |
| Gee, I wonder if the probe entry will be visible through a telescope, given that
it is so bright? Or is the geometry wrong?
Burns
|
| 560.694 | NASA laser space communications milestone achieved | PRAGMA::GRIFFIN | Dave Griffin | Wed Dec 16 1992 12:49 | 34 |
| Dwayne C. Brown
Headquarters, Washington, D.C. December 15, 1992
James H. Wilson
Jet Propulsion Laboratory, Pasadena, Calif.
RELEASE: 92-225
A major milestone in space communications was achieved recently when NASA
scientists successfully transmitted laser signals to the Galileo spacecraft at
a distance of 1.3 million miles (2.2 million kilometers).
"This experiment is part of a program to show that future deep space
missions can use laser beams to send back to Earth larger volumes of space-
acquired data than is currently possible using radio signals", said Dr. James
Lesh, Principal Investigator at NASA's Jet Propulsion Laboratory, Pasadena,
Calif.
Laser beams were simultaneously transmitted to Galileo from a 24- inch
(61-centimeter-diameter) telescope at Table Mountain Observatory near
Wrightwood, Calif., and a 60-inch (1.5-meter) telescope at the U.S. Air Force
Phillips Laboratory's Starfire Optical Range near Albuquerque, N.M. The laser
beams from both sites were detected by Galileo's onboard camera.
Called the Galileo Optical Experiment (GOPEX), the experiment began on
Dec. 9 as Galileo flew by Earth on its way to Jupiter. The experiment will
continue through Dec. 16 when the distance of Galileo will be 3.7 million miles
(6 million kilometers).
The experiment is operated by the JPL Telecommunications and Data
Acquisition Technology Development Office, with overall management
responsibility by NASA's Office of Space Communications, Advanced Systems
Program, Washington, D.C.
Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61
|
| 560.695 | Updates - December 11-18 | VERGA::KLAES | I, Robot | Fri Dec 18 1992 17:33 | 469 |
| Article: 2661
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/11/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 12 Dec 1992 06:33:57 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
December 4 - 10, 1992
SPACECRAFT
1. On December 4, real-time commands were sent to change the telemetry rate
from 115.2 kbps to 28.8 kbps so that DSS-12 (Goldstone 34 meter antenna)
could process downlink telemetry. This change was necessary when ground
station problems at DSS-14 (Goldstone 70 meter antenna) caused the Project
to request tracking support at DSS-12. The spacecraft telemetry rate under
stored sequence control was switched back to 115.2 kbps after DSS-12 tracking
support ended. Upon completion of commanding, the CDS (Command Data
Subsystem) command lock counter had increased by 4 which was 2 more than
expected. No unplanned commands were received/processed by the spacecraft.
Analysis of this incident is in progress.
2. On December 4, Part 1 of the EE-11 Earth encounter sequence memory load
was uplinked to the spacecraft without incident. Part 2 of the EE-11 Earth
encounter sequence memory load was uplinked on December 7. This sequence
covers spacecraft activities from December 7, 1992 to December 28, 1992 and
includes the Earth closest approach on December 8, 1992.
The December 7 EE-11 uplink was delayed for approximately 45 minutes
while the ground station transmitter configuration was changed from 18kw with
4db command modulation suppression to 5.5kw with 0.5db command modulation
suppression to eliminate command feedthru degradation of downlink telemetry.
3. During this reporting period, numerous science instrument
calibration/characterization activities were performed to take advantage of
the high telemetry data rates while close to the Earth. Activities included
Magnetometer (MAG) scan platform interference test, Solid State Imaging (SSI)
boomscatter test, and a MAG calibration coil. All calibration/characterization
activities were performed nominally and data analysis is in progress.
4. On December 5, real-time commands were sent to update the gyro drift
parameters using spacecraft gyro data collected on November 29. This update
was performed to meet the scan platform pointing requirements in support
of Earth 2 science data collection when the star scanner shutter was closed.
5. On December 5, real-time commands were sent to disable the AACS (Attitude
and Articulation Control Subsystem) sun-dependent algorithms and enable the
AACS bright body fault protection in preparation for the Earth 2 flyby. The
commands executed nominally on the spacecraft prior to the start of the EE-11
Earth encounter sequence.
6. On December 5 and 6, NO-OP commands were sent to reset the command loss
timer to 72 hours, its planned value during this mission phase.
7. On December 8, Earth closest approach occurred at 7:09:25 AM PST at an
altitude of 303.1 km. The Earth Gravity Assist (EGA) was performed flawlessly.
During the Earth closest approach time period, the Galileo spacecraft took
observations of the magnetosphere, Moon and Earth system.
8. On December 8, approximately three hours after closest approach, real-time
commands were sent to enable the AACS attitude control sun dependent
algorithms to their nominal post fly-by state. Also, the command loss timer
was reset to 11 days in accordance with the EE-11 sequence strategy.
9. On December 8, real-time commands were sent to update the attitude control
bright body vector in the EE-11 Earth encounter sequence to permit star set
acquisition for the December 10 stored-sequence SITURN.
10. On December 8, after approximately 8 hours after closest approach,
real-time commands were sent at PI (Principal Investigator's) request to turn
off the Energetic Particle Detector (EPD) LEMMS-A detector bias.
11. On December 9, the Galileo Optical Communications Experiment from an
Earth-based Xmitter (GOPEX) experiment began. This experiment consists of
pulsing a laser at the Galileo spacecraft from the Table Mountain Observatory
(TMO) and the Starfire Optical Range (SOR). The Solid State Imaging (SSI)
camera is shuttered while slewing across the Earth resulting in a series of
illuminated pixels in the image. The experiment is continuing at the writing
of this report. Preliminary analysis of the data is in progress.
12. On December 10, the spacecraft executed an 11-degree SITURN. The main
purpose of the SITURN was to maintain the spacecraft within plus or minus 10
degrees of the sun at the current solar distance.
13. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 16DN to 17DN and now reads 17DN (3.9 volts).
The DC measurement has ranged from 115DN (13.4 volts) to 148DN (17.4 volts)
and now reads 132DN (15.5 volts). These measurement variations are consistent
with the model developed by the AC/DC special anomaly team.
14. The Spacecraft status as of December 10, 1992, is as follows:
a) System Power Margin - 59 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 4 degree
off-sun (leading) and 95 degrees off-earth (leading)
e) Downlink telemetry rate/antenna-67.2kbps (coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all instruments are powered on except the PPR
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 215 hours
TRAJECTORY
As of noon Thursday, December 10, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 1,583,900 km (.01 AU)
Distance from Sun 147,088,200 km (0.98 AU)
Heliocentric Speed 140,500 km per hour
Distance from Jupiter 857,457,800 km
Round Trip Light Time 0 minutes, 12 seconds
SPECIAL TOPIC
1. As of December 10, 1992, a total of 8786 real-time commands have been
transmitted to Galileo since Launch. Of these, 3753 were initiated in the
sequence design process and 5033 initiated in the real-time command process.
In the past week, 74 real time commands were transmitted: 72 were initiated
in the sequence design process and 2 initiated in the real time command
process. Major command activities this week included commands to change the
telemetry rate, uplink the EE-11 Earth encounter sequence memory load, update
gyro drift parameters, disable sun-dependent algorithms, enable bright body
fault protection, reset the command loss timer, enable the sun-dependent
algorithms, update the bright body vector, and turn the EPD detector bias off.
2. Intermittent telemetry has been observed since Earth closest approach as
a result of a 6db variation in signal levels received at the tracking stations.
The causes for these variations is presently unknown, but is likely the result
of spacecraft boom/structural interference, high telecom cone angles
(>110 degrees) and possibly RF leakage from LGA-2 (Low Gain Antenna #2).
After the SITURN on December 10, the cone angle was approximately 95 degrees
and the ground received signal variations and data degradations were
considerably reduced. Analysis of the trajectory and the stored-sequence
planned SITURN indicates that the cone angle will not again reach 100 degrees.
A stored-sequence SITURN on December 16, prior to the Earth/Moon conjunction
playback, will further reduce the cone angle to less than 85 degrees. At cone
angels less than 85 degrees no boom/structural interferences is possible;
correspondingly telecommunication performance is expected to further improve.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2668
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/14/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 15 Dec 1992 03:09:18 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 14, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Over the weekend, science instrument calibration and characterization
activities were performed. Continuous tracking was scheduled over DSS-12
(Goldstone 34 meter antenna), DSS-14 (Goldstone 70 meter antenna), DSS-43
(Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, December 14, 1992, a sun vector update is scheduled. The GOPEX
experiment is continuing and is scheduled to complete on December 16.
Real-time commands are scheduled to disable attitude control bright body fault
protection, and a NO-OP command to reset the Command Loss Timer. Continuous
tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, the GOPEX experiment is continuing. A SITURN of 14 degrees is
also scheduled. Continuous tracking is scheduled over DSS-14, DSS-43 and
DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The 3 things that children
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/ |_|/ |_____|/ | space, dinosaurs and ghosts.
Article: 2673
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/15/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 16 Dec 1992 02:24:35 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 15, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, a sun vector update was performed. The GOPEX experiment
continued and is scheduled to complete on December 16. Real-time commands
were sent to disable attitude control bright body fault protection, as planned.
Continuous tracking was scheduled over DSS-14 (Goldstone 70 meter antenna),
DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, December 15, 1992, the GOPEX experiment is continuing. A SITURN
of about 14 degrees is also scheduled. Continuous tracking is scheduled over
DSS-14, DSS-43 and DSS-63.
Tomorrow, the Earth/Moon Conjuction movie is scheduled. Continuous
tracking is scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in you life.
Article: 2692
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/16/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 17 Dec 1992 07:33:07 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 16, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, the GOPEX experiment continued. A SITURN of about 14 degrees
was performed, as planned. Real-time commands were sent to configure the
spacecraft telecommunciations subsystems for planned future operations.
Continuous tracking was scheduled over DSS-14 (Goldstone 70 meter antenna),
DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, December 16, 1992, the Earth/Moon Conjuction movie is scheduled.
The GOPEX experiment completed today. Continuous tracking is scheduled over
DSS-14, DSS-43 and DSS-63.
Tomorrow, the Earth/Moon Conjunction movie playback is scheduled to begin.
Real-time commands are scheduled to disable the system fault protection
thruster firing all-clear response and to enable the Plasma detector science
alarm monitor. Near continuous tracking is scheduled over DSS-14, DSS-43 and
DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in you life.
Article: 2699
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/17/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Fri, 18 Dec 1992 06:26:26 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 17, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 7.68 Kbps (7680 bits/second).
Yesterday, the Earth/Moon Conjuction movie was performed, as planned.
Also, the GOPEX experiment completed. Real-time commands were sent to
turn the Plasma detector instrument off. Continuous tracking was scheduled
over DSS-14 (Goldtstone 70 meter antenna), DSS-43 (Canberra 70 meter antenna)
and DSS-63 (Madrid 70 meter antenna).
Today, December 17, 1992, the Earth/Moon Conjunction movie playback is
in progress. Real-time commands are scheduled to disable the system fault
protection thruster firing all-clear response and to enable the Plasma detector
science alarm monitor. Near continuous tracking is scheduled over DSS-14,
DSS-43 and DSS-63.
Tomorrow, the playback of the Earth/Moon Conjunction movie will continue.
A routine RPM (Retro-Propulsion Module) thruster flushing maintainance activity
is also scheduled. Continuous tracking is scheduled over DSS-14, DSS-43 and
DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in you life.
Article: 2703
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/18/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 19 Dec 1992 01:10:48 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
December 11 - 17, 1992
*************************************************************
Merry Christmas and Happy New Year!!
Because of the Christmas Holiday, the Mission Director Report
will not be published next week. The next report will be on
January 7, 1992.
*************************************************************
SPACECRAFT
1. On December 11, real-time commands were sent to turn ranging off in order
to maximize the downlink telemetry performance for the science instrument
calibration activities scheduled later in the day.
2. On December 12, real-time commands were sent to zero out the Bright Body
Avoidance (BBA) vector onboard the spacecraft. This vector was causing the
star scanner shutter to close sooner than expected resulting in infrequent
dropouts of the first star in a two star set. This action was taken to
eliminate the possibility of the star dropouts increasing and causing SEQID
to fail which in turn would have caused the gyros to be selected as the
primary attitude source and would have adversely effected scan platform
priority and the possibility of tripping gyro fault protection.
3. On December 12, real-time commands were sent to turn Two-Way Noncoherent
(TWNC) on prior to the sequence controlled Extreme Ultraviolet Spectrometer
(EUV)/Ultraviolet Spectrometer (UVS) cross calibration activity.
4. On December 13, the spacecraft went through perihelion at a solar distance
of .982 AU. All spacecraft temperatures were near predicted levels.
5. On December 14, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value during this mission phase.
6. On December 14, a routine sun vector update was performed. This sun
vector is valid until December 31, 1992.
7. On December 15, real-time commands were sent to disable the attitude
control bright body avoidance fault protection after the completion of the
Earth 2 flyby.
8. On December 15, real-time commands were sent to turn the TWNC off prior
to the SITURN on December 16 in order to receive two-way doppler data for
navigation purposes.
9. On December 16, the spacecraft executed a 14-degree SITURN which brought
the cone angle down from approximately 95 degrees to 83 degrees. Subsequently,
the telecommunication performance improved prior to the Earth/Moon conjunction
movie playback beginning on December 17 and continuing into December 19.
10. On December 16, the Galileo Optical Communications Experiment from an
Earth-based Xmitter (GOPEX) experiment was completed. This experiment
consisted of pulsing a laser at the Galileo spacecraft from the Table Mountain
Observatory (TMO) and the Starfire Optical Range (SOR). The Solid State
Imaging (SSI) camera was shuttered while slewing across the Earth resulting
in a series of illuminated pixels in the image. Initial results indicate that
laser transmissions were successfully detected from both TMO and SOR. Data
analysis is continuing.
11. On December 17, real-time commands were sent at the direction of the PI
(Principal Investigator) to turn the Plasma Detector (PLS) instrument off
approximately 31 hours before the stored sequence onboard the spacecraft
would have turned the instrument off. The instrument temperature at turn off
was approximately 43.7 degrees C which was less than one degree below the
maximum waived temperature limit of 44.4 degrees C.
12. During the reporting period, numerous science instrument
calibrations/characterization activities were performed to take advantage of
the high telemetry data rates while close to the Earth. Activities included
Near Infrared Mapping Spectrometer (NIMS) partial Photometric Calibration
Target (PCT) calibration, NIMS partial Radiometric Calibration Target (RCT)
calibration, Extreme Ultraviolet Spectrometer (EUV)/Ultraviolet Spectrometer
(UVS) cross calibration, EUV star calibration, UVS syscan, NIMS mirror scan
calibration, Plasma Wave (PWS) calibration, and Solid State Imaging (SSI)
partial PCT. All calibration/characterization activities were performed
nominally and data analysis is in progress.
13. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 13DN to 17DN and now reads 17DN (3.9 volts).
The DC measurement has ranged from 44DN (4.7 volts) to 157DN (18.5 volts) and
now reads 157DN (18.5 volts). These measurement variations are consistent
with the model developed by the AC/DC special anomaly team.
14. The Spacecraft status as of December 17, 1992, is as follows:
a) System Power Margin - 79 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15 rpm/Star Scanner
d) Spacecraft Attitude is approximately 6 degree
off-sun (leading) and 83 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- all instruments are powered on
except the PPR, NIMS, and PLS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 240 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-12 (Earth-Earth 12) Preliminary Sequence and Command Generation
products were approved by the Project on December 16, 1992. This sequence
covers spacecraft activities from January 20, 1993 to January 23, 1993 and
from February 8, 1993 to April 12, 1993.
2. The Dual Drive Actuator (DDA-5) Part A sequence memory load was approved
for transmission by the Project on December 17, 1992. This sequence covers
High Gain Antenna (HGA) motor hammering activities from December 28, 1992
through January 4, 1993. Part B of this sequence will be reviewed for
approval on December 30, 1992, subsequent parts of the overall DDA-5 sequence
will be reviewed and approved as needed after January 4, 1993. The commands
for windup/hammering activities on December 29 and 30 were also reviewed.
Individual sets of hammering/windup commands will be approved as required
immediately prior to being uplinked to the spacecraft.
TRAJECTORY
As of noon Thursday, December 17, 1992, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 6,928,300 km (.05 AU)
Distance from Sun 147,267,200 km (0.99 AU)
Heliocentric Speed 140,300 km per hour
Distance from Jupiter 836,434,500 km
Round Trip Light Time 0 minutes, 48 seconds
SPECIAL TOPIC
1. As of December 17, 1992, a total of 8815 real-time commands have been
transmitted to Galileo since Launch. Of these, 3768 were initiated in the
sequence design process and 5047 initiated in the real-time command
process. In the past week, 29 real time commands were transmitted: 15 were
initiated in the sequence design process and 14 initiated in the real time
command process. Major command activities this week included commands to
turn ranging off, zero out the bright body vector, turn the TWNC on, reset
the command loss timer, turn the TWNC off, disable the bright body avoidance
fault protection, and turn the PLS instrument off.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in you life.
|
| 560.696 | Flyby Earth briefing and mission to Jupiter | VERGA::KLAES | I, Robot | Tue Dec 22 1992 18:12 | 118 |
| Article: 2704
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Earth Flyby Briefing Set For Dec 22
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 19 Dec 1992 03:17:39 GMT
Paula Cleggett-Haleim
Headquarters, Washington, D.C. December 18, 1992
(Phone: 202/358-0883)
Bob MacMillin
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
EDITORS NOTE: N92-109
MEDIA BRIEFING SET ON GALILEO FLYBY EARLY SCIENCE RESULTS
Photographs and video clips from the Galileo spacecraft's flyby of the
Earth and moon will be released at a news conference on Tuesday, Dec. 22.
The briefing will originate from NASA's Jet Propulsion Laboratory, Pasadena,
Calif., beginning at 1 p.m. EST.
The press conference, carried live on NASA Select television, can be
viewed from the NASA Headquarters, auditorium, 400 Maryland Washington, D.C.
In addition to the release of images, Galileo scientists will discuss
observations made during the flyby, which culminated with Galileo's closest
approach to Earth on Dec. 8. Also, scientists will present new results from
Galileo's 1991 flyby of the asteroid Gaspra, as well as the outcome of a recent
laser communications experiment.
Presenters will include Project Manager William J. O'Neil and Project
Scientist Dr. Torrence Johnson.
NASA Select TV is carried on GE Satcom F2R, transponder 13, C
band, 72 degrees west longitude, transponder frequency 3960 MHz, audio
subcarrier 6.8 MHz, vertical polarization.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in you life.
Article: 2708
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo On Course For Jupiter
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Sat, 19 Dec 1992 07:04:21 GMT
From the "JPL Universe"
December 18, 1992
Galileo on course for Jupiter
NASA's Galileo spacecraft flew by the Earth Dec. 8 at 7:09
a.m. PST at an altitude of 304 kilometers (189 miles) above the
South Atlantic Ocean, completing a three-year gravity-assist
program and setting a course to reach Jupiter in December 1995.
"How sweet it is," said Galileo Project Manager William
O'Neil. "We are on the way to Jupiter."
This, the third gravity-assist for Galileo, added about 3.7
kilometers per second (8,300 mph) to the spacecraft's speed in
its solar orbit and changed its direction slightly, so that its
elliptical orbit now will reach to the orbit of Jupiter, about
780 million kilometers (480 million miles) from the sun.
Traveling at over 48,000 kilometers per hour (30,000 mph) on
its way to the Earth encounter, the spacecraft flew 110,000
kilometers (about 68,000 miles) north of the moon at 7:58 p.m.
PST Dec. 7. Departing from the Earth in a slightly southerly
direction, it crossed the moon's orbit at about 6:15 p.m. PST on
Dec. 8.
JPL's Galileo flight team programmed the spacecraft to
measure the near-Earth environment and observe Earth and moon
during this flyby. Scientists will obtain a great many images and
spectral scans of the northern regions of the moon and of various
areas on Earth over a period lasting several days. This provides
scientific data from new perspectives in some cases, and helps
the scientists calibrate their instruments for the Jupiter
orbital mission planned for 1995-97.
O'Neil said the project is very much looking forward to
"unprecedented" views of the Earth and moon, and that color
images, shot about every 15 minutes during a 14-hour period, will
be compiled into a video that is expected to be released Dec. 22.
"For 14 hours, we'll be able to construct effectively a movie of
the moon traversing the foreground of the Earth," he said.
On the way to Jupiter, Galileo will fly within 960
kilometers (600 miles) of the asteroid Ida on Aug. 28, 1993.
The Galileo orbiter will fly 10 different elliptical orbits
of Jupiter, with close passes by each of the major satellites and
extended observations of the planet and its magnetosphere.
Galileo's atmospheric probe, which will descend into Jupiter's
atmosphere on Dec. 7, 1995 to observe that environment for the
first time, is being checked out during the near-Earth flight.
###
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in you life.
|
| 560.697 | Images and films of Earth and Luna released | VERGA::KLAES | I, Robot | Wed Dec 23 1992 18:39 | 61 |
| Article: 1510
From: clarinews@clarinet.com (UPI)
Newsgroups: clari.tw.space,clari.news.gov.agency,clari.tw.aerospace
Subject: NASA releases images of Earth and Moon
Date: Tue, 22 Dec 92 13:01:29 PST
PASADENA, Calif. (UPI) -- NASA Tuesday released a series of
still pictures and three short movies collected by the Galileo space
probe when the craft passed Earth and the Moon earlier this month.
Along with other scientific data, Galileo gathered an array of
images, including detailed pictures of the unexplored north pole of
the Moon and pictures that were compiled into mosaics to make short
films of the Moon and Earth moving through space.
Galileo passed within 189 miles of Earth on Dec. 8 as part of
the craft's circuitous journey to explore Jupiter. Officials used the
close encounter to calibrate the probe's various sensors and cameras
by studying and photographing the Earth and Moon in the most extensive
such observations ever.
Along with pictures, officials released a short tape of sounds
the probe recorded that would suggest the presence of intelligent life
if the probe were exploring Earth as another world. The sounds may
have come from a maritime radio navigation beacon.
``It sounds a little bit like my kids when they were
practicing musical instruments,'' joked project scientist Torrence
Johnson during a briefing at the Jet Propulsion Laboratory.
``But I assure you, had we heard something like that...at some
other planet you would definitely have some real headlines to write
about and we would furiously be trying to decode it,'' he said.
Named after the Italian astronomer credited with discovering
Jupiter's four brightest moons, the 5,990-pound Galileo is the most
sophisticated interplanetary spacecraft ever built, equipped with a
battery of 10 state-of-the-art instruments.
Galileo was launched from the space shuttle Atlantis on Oct. 18,
1989, kicking off a six-year, three-planet celestial billiard shot
requiring the probe to sail once past Venus and twice past Earth for
velocity-boosting gravity-assist flybys required to propel the probe
on to distant Jupiter.
Other than a balky antenna, the atomic-powered, $1.4 billion
craft was healthy despite having traveled some 1.5 billion miles,
officials said.
Galileo will fly within 600 miles of the asteroid Ida on Aug.
28, 1993. Finally, on Dec. 7, 1995, Galileo will flash past the
volcanic moon Io at an altitude of just 600 miles, using the bizarre
moon's gravity to help decelerate into the Jupiter's system, lining up
on a trajectory that will carry it over the point where the entry
probe will hit the planet's atmosphere.
If all goes well, the spacecraft will drop an instrumented
probe into Jupiter's stormy atmosphere before the mothership slips
into orbit around the giant planet in December 1995 for a planned
20-month tour.
|
| 560.698 | HGA Hammering starts today | DECWIN::FISHER | I *hate* questionnaires--Worf | Tue Dec 29 1992 14:14 | 5 |
| Today is the day they start "hammering" HGA. Keep your fingers
crossed!
Burns
|
| 560.699 | Hammering GALILEO to get the HGA fully open | VERGA::KLAES | I, Robot | Tue Dec 29 1992 19:29 | 40 |
| Article: 2902
From: clarinews@clarinet.com (UPI)
Newsgroups: clari.tw.space,clari.local.california
Subject: Effort begins to free space probe's balky antenna
Date: Mon, 28 Dec 92 19:56:53 EST
PASADENA, Calif. (UPI) -- Engineers Monday turned the Galileo space
probe so that the craft's balky antenna faced the sun as the first step
of an effort to free its stuck transmitter.
Ground controllers in Pasadena sent signals to the speeding craft
that adjusted its position by about 45 degrees, placing Galileo's
``high-gain'' antenna into sunlight.
Officials planned to keep the craft in that position and Tuesday
morning begin turning on and off two small electric motors five times
every four seconds in the hopes of popping the antenna free.
The effort is aimed at fully deploying the antenna, which is needed
to transmit priceless data the craft will collect when it begins
exploring Jupiter in 1995.
Galileo was launched from the space shuttle Atlantis on Oct. 18,
1989, kicking off a six-year, three-planet celestial billiard shot
requiring the probe to sail once past Venus and twice past Earth for
velocity-boosting gravity-assist flybys required to propel the probe on
to distant Jupiter.
But after the $1.4 billion craft was launched, ground controllers
were unable to fully deploy the high-gain antenna. The antenna is
constructed like an umbrella, with 18 ribs supporting a wire mesh that
would form a parabolic dish about 15 feet in diameter when fully opened.
Engineers hope that the heat from the sun will stretch the antenna's
mast enough so that the pins will pop loose when the motors are pulsed.
The craft, traveling at about 86,000 mph, is about 9.4 million miles
from Earth and about 93.6 million miles from the sun, the closest point
to the sun since the problem was discovered.
|
| 560.700 | any new yet?? | KAOFS::R_YURKIW | reward those who bring bad news!! | Wed Dec 30 1992 17:43 | 1 |
| WELL????
|
| 560.701 | No News Yet...Tomorrow, maybe... | PONIL::J_BUTLER | E pur, si muove... | Wed Dec 30 1992 18:00 | 12 |
| Nothing yet. I don't expect any reports until tomorrow. They were going
to "hammer" the DDA for about 20 hours, then change back from warming
attitude, then reacquire celestial reference. After all that, then
they'll check for any changes in wobble and check for sensor obscuration.
If it works (even marginally), the champagne will flow on New Years at
JPL! If no movement is detected...well, things will be a bit more
restrained.
Regards,
John B.
|
| 560.702 | First hammering attempt failed | VERGA::KLAES | I, Robot | Wed Dec 30 1992 18:09 | 82 |
| Article: 2909
From: clarinews@clarinet.com (UPI)
Newsgroups: clari.tw.space,clari.news.gov.agency,clari.local.california
Subject: Attempt apparently fails to free space probe's jammed antenna
Date: Wed, 30 Dec 92 8:39:32 PST
PASADENA, Calif. (UPI) -- An attempt to free the Galileo space
probe's jammed main antenna apparently has failed, but NASA technicians
plan to keep trying to salvage the craft's full mission to explore Jupiter,
officials said Wednesday.
About 20 hours of ``hammering'' the balky antenna with onboard
electric motors apparently ended at about 3 a.m. PST Wednesday without
popping the antenna open, said Jim Wilson, a spokesman at NASA's Jet
Propulsion Laboratory.
However, beginning some time next week, engineers planned to
resume working to deploy the antenna fully and will probably repeat
the procedure over the next few weeks, he said. ``They're just going
to continue for several weeks without a deadline,'' Wilson said.
The effort to fully deploy the antenna is needed to transmit
priceless data the craft will collect when it begins exploring Jupiter
in 1995.
At about 7 a.m. Tuesday, technicians activated two small electric
motors on the speeding space probe that control a mechanism designed to
push open the ``high-gain'' antenna.
Two hours later, engineers started a series of attempts to jar loose
the antenna by making the motors repeatedly push on the antenna in quick
succession. Officials continued the routine until about 3 a.m. Wednesday.
Galileo was launched from the space shuttle Atlantis on Oct. 18,
1989, kicking off a six-year, three-planet celestial billiard shot
requiring the probe to sail once past Venus and twice past Earth for
velocity-boosting gravity-assisted flybys required to propel the probe
on to distant Jupiter.
But ground controllers were unable to deploy the $1.4 billion craft's
high-gain antenna fully as planned in 1991. The antenna is constructed
like an umbrella, with 18 ribs supporting a wire mesh that would form a
parabolic dish about 15 feet in diameter when fully opened.
Each rib has a metal pin at the end that held it in place before the
antenna was opened. Two of the pins apparently became stuck, preventing
the antenna from fully opening.
On Monday, ground controllers adjusted the probe's position, placing
the high-gain antenna into sun light. Engineers hope that the heat from
the sun will stretch the antenna's mast enough so that jammed pins will
pop loose when the motors pulsed.
The craft, traveling at about 86,000 mph, is about 9.4 million miles
from Earth and about 93 million miles from the sun, the closest point to
the sun since the problem was discovered.
Several previous attempts using other strategies to free the stuck
antenna failed.
If the antenna is never fully deployed, scientists will have to
use the craft's slower low-gain antenna, which would sharply limit the
amount of data and images the craft will be able to send back to Earth.
The high-gain antenna can transmit data about 1,000 times faster then
the low-gain antenna.
Named after the Italian astronomer credited with discovering
Jupiter's four brightest moons, the 5,990-pound Galileo is the most
sophisticated interplanetary spacecraft ever built, equipped with a
battery of 10 state-of-the-art instruments.
Galileo will fly within 600 miles of the asteroid Ida on Aug.
28, 1993. Finally, on Dec. 7, 1995, Galileo will flash past the
volcanic moon Io at an altitude of just 600 miles, using the bizarre
moon's gravity to help decelerate into Jupiter's system, lining up on
a trajectory that will carry it over the point where the entry probe
will hit the planet's atmosphere.
If all goes well, the spacecraft will drop an instrumented probe
into Jupiter's stormy atmosphere before the mothership slips into orbit
around the giant planet in December 1995 for a planned 20-month tour.
|
| 560.703 | | HELIX::MAIEWSKI | | Wed Dec 30 1992 18:49 | 8 |
| Every report seems to insist that the pins are stuck. I wonder why no one
is considering the possibility that some piece of insulation might have wrapped
itself around the ribs effectively tying them together.
Maybe those sort of theories are discouraged since there would be little
chance of recovering from that type of problem.
George
|
| 560.704 | Galileo Update 12/30/92 | PONIL::J_BUTLER | E pur, si muove... | Thu Dec 31 1992 13:44 | 55 |
| Article 2763 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!enterpoop.mit.edu!usc!sdd.hp.com!saimiri.primate.wisc.edu!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/30/92
Message-ID: <1992Dec30.223543.23648@news.arc.nasa.gov>
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: news@elroy.jpl.nasa.gov (Usenet)
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Wed, 30 Dec 1992 22:34:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 37
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
December 30, 1992
The Galileo spacecraft is operating normally in the dual-
spin mode and is transmitting coded telemetry at 1200 bits per
second. It is about 16.5 million kilometers (10.25 million
miles) from Earth, and about 152 million kilometers (94 million
miles) from the Sun.
Yesterday, December 29, after approximately 20 hours of
warming in sunlight, the antenna-deploy motors were turned on to
"wind up" the system and then pulsed to "hammer" it in an effort
to free the stuck ribs of Galileo's high-gain antenna. The
procedures began at 6:55 a.m. PST and continued until 2:48 a.m.
PST this morning, December 30. A total of 2160 pulses were
executed by the motors during this period. The stuck ribs were
apparently not freed. This morning the spacecraft was returned
from the warming attitude to the normal cruise mode.
No spacecraft activities are scheduled during the holiday
weekend. Activities will resume next week.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
|
| 560.705 | Probably Probabilities.... | PONIL::J_BUTLER | E pur, si muove... | Thu Dec 31 1992 13:55 | 23 |
| Re: .703
My guesses are that the rib problem is either:
1) The most probable cause as indicated by simulation and analysis
of the spare they have on the ground,
or
2) The most probable cause that they have any chance of fixing.
I _still_ would like to see a relay launched (modify a TDRS), but I
believe that solution has been rejected due to cost.
Too bad we couldn't raise a few hundred million dollars and donate
mission funding to NASA! :)
On a positive note, I think there are some gurus at JPL who are going
to learn a lot more about data compression in the years ahead!
Regards,
John B.
|
| 560.706 | Updates - December 22-30 | VERGA::KLAES | I, Robot | Thu Dec 31 1992 17:53 | 366 |
| Article: 2744
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/22/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Mon, 28 Dec 1992 15:20:38 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 22, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, minimal spacecraft activity was scheduled. Continuous
tracking was scheduled over DSS-14, DSS-43 DSS-61 and DSS-63.
Today, December 22, 1992, the DDA-5 (Dual Drive Actuator) part A sequence
memory load is being uplinked. This sequence covers HGA (High Gain Antenna)
warming turn and the motor actuation activities from December 28, 1992 through
January 4, 1993. Continuous tracking is scheduled over DSS-12, DSS-43 and
DSS-61.
Over the holiday period, minimal spacecraft activity is scheduled.
Tracking is scheduled over DSS-14, DSS-43, DSS-61 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2749
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo GIF Images Available
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Mon, 28 Dec 1992 17:21:00 GMT
=======================
GALILEO GIF IMAGES
December 28, 1992
=======================
Five Galileo images released at last week's press conference are now
available in GIF format (GIF89a). The images were scanned in from photographs
and are not the raw data. Caption files accompanying each image are attached
below, and the caption files are also embedded in the image. Make sure
you are in binary mode when downloading the images, and in ascii mode when
downloading the caption files. The Galileo images are available using
anonymous ftp to:
ftp: ames.arc.nasa.gov (128.102.18.3)
user: anonymous
cd: pub/SPACE/GIF
files:
andes.gif - False color mosaic of the Andes Mountains
andes.txt - caption file
earthmo2.gif - Color image of the Earth and Moon
earthmo2.txt - caption file
mideast.gif - Color image of the Middle East including Somalia
mideast.txt - caption file
moonfals.gif - False color mosaic of the northern regions of
the Moon
moonfals.txt - caption file
moongrid.gif - Gray scale Moon image with overlayed grid
moongrid.txt - caption file
-----------------------------------------------------------------------------
andes.txt
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
PHOTO CAPTION GALILEO
December 22, 1992 P-41493
TOP GLL/EM21
This false-color mosaic of the central part of the Andes
mountains of South America (70W, 19S) is made up of 42 images
taken by the Galileo spacecraft from an altitude of about 25,000
kilometers (15,000 miles). The combination of visible and near-
infrared filters (green, 0.76 micron and 1.0 micron) was chosen
for this picture to separate regions with distinct vegetation and
soil types. The mosaic shows the area where Chile, Peru, and
Bolivia meet. North is to the left, and the Pacific coast
(bottom of picture) is in the foreground. Lakes Titicaca and
Poopo are nearly black patches left to right; a large light blue
area below and left of Lake Poopo is Salar de Uyuni, a dry salt
lake some 120 kilometers (75 miles) across. These lakes lie in
the Altiplano, a region between the western and eastern Andes,
which are covered by clouds. The water/ice content of the clouds
is indicated by their shade of pink. The vegetated Gran Chaco
plains east of the Andes are pale green (top of picture). Light
blue patches in the mountains to the north (left) are glaciers.
The Galileo project, whose primary mission is the exploration o.f
the Jupiter system in 1995-97, is managed for NASA's Office of
Space Science and Applications by the Jet Propulsion Laboratory.
-----------------------------------------------------------------------------
earthmo2.txt
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109.
TELEPHONE (818) 354-5011
PHOTO CAPTION GALILEO
December 22, 1992 P-41508
TOP GLL/EM23
Eight days after its encounter with the Earth, the Galileo
spacecraft was able to look back and capture this view of the
Moon in orbit about the Earth, taken from a distance of about 6.2
million kilometers (3.9 million miles), on December 16. The
picture was constructed from images take through the violet, red,
and 1.0-micron infrared filters. The Moon is in the foreground,
moving from left to right. The brightly-colored Earth contrasts
strongly with the Moon, which reflects only about one-third as
much sunlight as Earth. Contrast and color have been computer-
enhanced for both objects to improve visibility. Antarctica is
visible through clouds (bottom). The Moon's far side is seen;
the shadowy indentation in the dawn terminator is the south-
Pole/Aitken Basin, one of the largest and oldest lunar impact
features, extensively studied from Galileo during the first Earth
flyby in December 1990. The Galileo project, whose primary
mission is the exploration of the Jupiter system in 1995-97, is
managed for NASA's Office of Space Science and Applications by
the Jet Propulsion Laboratory.
-----------------------------------------------------------------------------
mideast.txt
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109.
TELEPHONE (818) 354-5011
PHOTO CAPTION GALILEO
December 22, 1992 P-41474
TOP GLL/EM22
This color image of North-East Africa and Arabia was taken from
an altitude of about 500,000 kilometers (300,000 miles) by the
Galileo spacecraft on December 9, 1992, as it left the Earth enroute
to Jupiter. Most of Egypt (center left) including the Nile
Valley, the Red Sea (slightly above center), Israel, Jordan, and
the Arabian peninsula are cloud-free. In the center, below the
cloud on the coast, is Khartoum, at the confluence of the Blue
Nile and the White Nile. Somalia (lower right) is partly cloud-
covered. The Galileo project, whose primary mission is the
exploration of the Jupiter system in 1995-97, is managed for
NASAy's Office of Space Science and Applications by the Jet
Propulsion Laboratory.
-----------------------------------------------------------------------------
moonfals.txt
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
PHOTO CAPTION (TOP) P-41490
GLL/EM17
December 22, 1992
This false-color mosaic was constructed from a series of 53
images taken through three spectral filters by Galileo'simaging
system as the spacecraft flew over the northern regions of the
Moon on December 7, 1992. The part of the Moon visible from
Earth is on the left side in this view. The color mosaic shows
compositional variations in parts of the Moon's northern
hemisphere. Bright pinkish areas are highlands materials, such
as those surrounding the oval lava-filled Crisium impact basin
toward the bottom of the picture. Blue to orange shades indicate
volcanic lava flows. To the left of Crisium, the dark blue Mare
Tranquillitatis is richer in titanium than the green and orange
maria above it. Thin mineral-rich soils associated with
relatively recent impacts are represented by light blue colors;
the youngest craters have prominent blue rays extending from
them. The Galileo project, whose primary mission is the
exploration of the Jupiter system in 1995-97, is managed for
NASA's Office of Space Science and Applications by the Jet
Propulsion Laboratory.
-----------------------------------------------------------------------------
moongrid.txt
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
PHOTO CAPTION (TOP) P-41475
GLL/EM15
December 22, 1992
This mosaic picture of the Moon was compiled from 18 images taken
with a green filter by Galileo's imaging system during the
spacecraft's flyby on December 7, 1992, some 11 hours before its
Earth flyby at 1509 UTC (7:09 a.m. Pacific Standard Time)
December 8. The north polar region is near the top part of the
mosaic, which also shows Mare Imbrium, the dark area on the left;
Mare Serenitatis at center; and Mare Crisium, the circular dark
area to the right. Bright crater rim and ray deposits are from
Copernicus, an impact crater 96 kilometers (60 miles) in
diameter. Computer processing has exaggerated the brightness of
poorly illuminated features near the day/night terminator in the
polar regions, giving a false impression of high reflectivity
there. The digital image processing was done by DLR, the German
aerospace research establishment near Munich, an international
collaborator in the Galileo mission. The Galileo project, whose
primary mission is the exploration of the Jupiter system in 1995-
97, is managed for NASA's Office of Space Science and
Applications by the Jet Propulsion Laboratory.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2751
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/28/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Mon, 28 Dec 1992 18:47:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 28, 1992
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Over the holiday period from Wednesday through Sunday, minimal spacecraft
activity was scheduled. Tracking was scheduled over DSS-14 (Goldstone 70 meter
antenna), DSS-43 (Canberra 70 meter antenna), DSS-61 (Madrid 34 meter antenna)
and DSS-63 (Madrid 70 meter antenna).
Today, December 28, 1992, the HGA (High Gain Antenna) warming to a 45
degree off Sun angle is scheduled in preparation for the DDA-5 (Dual Drive
Actuator #5) windup hammering activities. Real-time commands are scheduled
to update the system fault protection response and to modify attitude control
fault protection precision level in support of the motor acuation activity.
Tracking is scheduled over DSS-43 and DSS-63.
Tomorrow, after approxiamately 28 hours at warming attitude, real-time
motor windup hammering commands are scheduled to be sent beginning at approx
6:56 AM PST for a period of up to 20 hours. Tracking is scheduled over DSS-14,
DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2757
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/29/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 29 Dec 1992 18:24:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
December 29, 1992
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, the HGA (High Gain Antenna) warming turn to an attidue of 45
degree off Sun angle was performed in preparation for the DDA-5 (Dual Drive
Actuator #5) windup/hammering activities. Real-time commands were sent
to update the system fault protection response and to modify attitude control
fault protection presistence level in support of the motor acuation activity.
Tracking was scheduled over DSS-43 (Canberr 70 meter antenna) and DSS-63
(Madrid 70 meter antenna).
Today, December 29, 1992, after approxiamately 20 hours at warming
attitude, real-time commands for motor windup/hammering activities are being
sent to begin at approxiamately 6:56 AM PST for a period of up to 20 hours.
Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43 and
DSS-63.
Tomorrow, the sun acquistion back from warming attitude is scheduled
to begin at 2:48 PST. The star scanner checkout and real-time commands to
reacquire celestial reference are scheduled. Also, real-time commands are to
be sent to reconfigure the spacecraft. Tracking is scheduled over DSS-14,
DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2763
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/30/92
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Wed, 30 Dec 1992 22:34:00 GMT
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
December 30, 1992
The Galileo spacecraft is operating normally in the dual-
spin mode and is transmitting coded telemetry at 1200 bits per
second. It is about 16.5 million kilometers (10.25 million
miles) from Earth, and about 152 million kilometers (94 million
miles) from the Sun.
Yesterday, December 29, after approximately 20 hours of
warming in sunlight, the antenna-deploy motors were turned on to
"wind up" the system and then pulsed to "hammer" it in an effort
to free the stuck ribs of Galileo's high-gain antenna. The
procedures began at 6:55 a.m. PST and continued until 2:48 a.m.
PST this morning, December 30. A total of 2160 pulses were
executed by the motors during this period. The stuck ribs were
apparently not freed. This morning the spacecraft was returned
from the warming attitude to the normal cruise mode.
No spacecraft activities are scheduled during the holiday
weekend. Activities will resume next week.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
|
| 560.707 | New Year off to a bad start | MAYDAY::ANDRADE | The sentinel (.)(.) | Mon Jan 04 1993 09:11 | 23 |
|
New Year NEWS ... Galileo Main Antena Still STUCK ...
Depressing, I was hopping the motor kicking would work. I guess this
means that chances to fully deploy the untena are now about ZERO, I
know that NASA will keep trying until Galileo runs out of gaz, but
this was the last good chance they had.
Hope they at least learned something from it. Antena deployment has
always been a royal pain in the rear. And its about time they came up
with a design that is fail safe. At the very least they should retink
Antena Rib Pins... so that oil or no oil, Venus swing or not the darn
things will not prevent deployment of future Spacecraft Antenas.
Another thing a telescoping combination camera/manipulating arm may not
be a bad idea for future space craft. Nowadays it could be an economic
thing to do, the whole thing need not mass more then half a kilogram,
and it would help in a lot in situations like this. Not to talk about
the great propaganda pictures that it could take of the spacecraft in
flight, against various backgrounds, stars, planets, moons, etc.
Gil
|
| 560.708 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Mon Jan 04 1993 15:48 | 10 |
| It's hard to tell if the "We'll continue to try hammering" is putting on a good
face, or if they really believe there is a chance something will happen when they
try it again.
You can't help but wonder if maybe they got the scenario completely wrong.
("Well Grmbvfcxcz, we really fixed those humans that time! Quick, let's return
the super-glue before Mom notices that it is missing!")
Burns
|
| 560.709 | | HELIX::MAIEWSKI | | Mon Jan 04 1993 16:00 | 15 |
| NASA and mechanical things! I read a report that said the robot only got 20
feet down the volcano in Antarctica and the cable got stuck. It was the Globe
so I'd want to see more before believing it to be true but I wouldn't be
surprised.
Can you imagine what it would be like to see a bunch of NASA guys fishing? I
can invasion this scene full of guys in white shirts, ties, and fishing boots
standing knee deep in a river, some picking away at jammed fishing lines, some
trying to untangle them from trees and others completely wrapped up like
cocoons.
I have a similar scene for a rainy day in Texas when the same bunch walks
out the door after work, hundreds of guys struggling to open their umbrellas.
George
|
| 560.710 | Galileo HGA *did* show some change | DECWIN::FISHER | I *hate* questionnaires--Worf | Mon Jan 04 1993 18:36 | 41 |
| Wrong topic, George. But anyway, Dante got down 20 Ft and the data cable broke
at a kink (antennae and cable reels, huh?). The robot was retrieved.
But anyway, here is an interesting and encouraging bit of news about Galileo:
In article <1993Jan3.182812.13825@elroy.jpl.nasa.gov>, pjs@euclid.jpl.nasa.gov
writes...
>In article <1993Jan2.234235.16100@ee.ubc.ca>, davem@ee.ubc.ca (Dave Michelson)
writes:
>> In article <2JAN199323293310@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron
Baalke) writes:
>> >The hammering sessions will continue all the way through the entire month
>> >of January, if necessary. Even though the first hammering attempt didn't
>> >open up the antenna all the way, it did have a postive effect.
>>
>> !! It did? I sure don't remember seeing reference to that in the last
>> report but I'm glad to hear it.
>>
>> What was the "positive effect"? How was it determined or measured?
>
>The GLL nav team chief told me the other day that although nothing
>had unfurled, the degree of bowing had increased. This was determined
>from sun sensor data. On the premise that any movement is better than
>none, this is a positive effect. They're quite prepared to break the
>HGA if necessary, assuming they can.
The sun sensor data has indicated that the hammering has affected the
antenna in some way. Either the tension on the antenna has been increased
or a rib has sprung loose, it cannot be determined which way at this point.
Some clarification on "breaking the HGA". The two motors may apply enough
force to be able to break the stuck ribs, but having an open High Gain
antenna with a couple of broken ribs is a much better situation than having
to use the Low Gain antenna by itself.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
|
| 560.711 | Did we see a message in here indicating there was a change? | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Mon Jan 04 1993 18:57 | 8 |
| H*ll, hammer it all the way to orbit. If they aren't going to use it partially
unfurled, what have they got to lose. Glad to hear there was some "effect"
Question: Isn't a misshapened, partially unfurled antenna better than the LGA
anyway? can't we do some "Magic" on the recieving end to get better than LGA
speeds off one of the non-symetrical signal lobes? If the transmitter can't
slow down enough, how about sending each bit X times and reconstructing from
the degraded signal?
|
| 560.712 | Better then nothing | MAYDAY::ANDRADE | The sentinel (.)(.) | Tue Jan 05 1993 08:25 | 12 |
|
They sure didn't say anything about any changes in the oficial reports
a few replies back. But boy its nice to hear that something has changed,
even if they break the HGA they will be no worse off then now.
I forget if it has been mentioned in the previous 700 replies, but I
was wondering if the reason that the pins don't move is because they
are vacum welded to their sockets, rather they just stuck. Could the
extra trip to Venus (with no lubrificant) have done that ?
Gil
|
| 560.713 | HGA -- More Information | PONIL::J_BUTLER | E pur, si muove... | Tue Jan 05 1993 14:06 | 42 |
| Article 54393 of sci.space:
Xref: nntpd2.cxo.dec.com sci.astro:30269 sci.space:54393
Newsgroups: sci.astro,sci.space
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!caen!spool.mu.edu!sdd.hp.com!elroy.jpl.nasa.gov!kelvin.jpl.nasa.gov!baalke
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Re: Galileo's antenna
Message-ID: <4JAN199317595383@kelvin.jpl.nasa.gov>
News-Software: VAX/VMS VNEWS 1.41
Sender: news@elroy.jpl.nasa.gov (Usenet)
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
References: <IfG6hqu00XsFRFwEc9@andrew.cmu.edu>
Date: Mon, 4 Jan 1993 17:59:00 GMT
Lines: 25
In article <IfG6hqu00XsFRFwEc9@andrew.cmu.edu>, bluelobster+@CMU.EDU (David O Hunt) writes...
>Is there anyway of telling that the hammering is making progress (aside
>from rib release)?
The sun sensor and wobble measurements are the two main indicators. The
shadow of the antenna falling across the sun sensor is used measure the extent
the antenna is open. Since the stuck ribs cause the antenna to be
more open on one side than the other (asymmetrically deployed) and the
spacecraft is spinning, a slight wobble exists which can be measured.
Also, when the antenna is fully open, a couple of switches will be activated.
After the first antenna hammering last week, the sun sensor and wobble
measurments indicated a change in the antenna, the first change measured
since the initial antenna deployment attempt in April 1991. The recent
sun sensor data indicates that the antenna is "more open", and this is either
due to one of the three stuck ribs popping loose,
or increased tension on the antenna is causing it to bend out more. Several
more hammering sessions are scheduled this month to keep applying more force
on the ballscrew to free the stuck ribs.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
|
| 560.714 | | HELIX::MAIEWSKI | | Tue Jan 05 1993 14:35 | 42 |
| RE <<< Note 560.710 by DECWIN::FISHER "I *hate* questionnaires--Worf" >>>
>Wrong topic, George. But anyway, Dante got down 20 Ft and the data cable broke
>at a kink (antennae and cable reels, huh?). The robot was retrieved.
Not really. I see a big relationship between the HGA and the Robot. When ever
NASA has to do something mechanical they almost always fail. The HGA won't
open, the Robot breaks after going 20 feet, the thethered satellite would only
deploy a fraction of it's distance, the shuttle doors often threaten to jam, a
swivel camera on the moon got stuck looking straight up, etc, etc, etc.
Granted the environment is a difficult one for mechanical devices, but it
seems that considering their poor track record in this area that it needs more
study and attention.
RE Note 560.711 GAUSS::REITH "Jim 3D::Reith MLO1-2/c37 223-2021"
>Question: Isn't a misshapened, partially unfurled antenna better than the LGA
>anyway? can't we do some "Magic" on the receiving end to get better than LGA
>speeds off one of the non-symetrical signal lobes? If the transmitter can't
>slow down enough, how about sending each bit X times and reconstructing from
>the degraded signal?
I think I mentioned this once before but I talked to a bunch of guys from JPL
about the HGA when I was at DECUS in Anaheim. They said that the HGA is useless
in it's current configuration but they felt that the project would be a success
even if they had to use the LGA. They said there were many advances in both the
ground antenna receiving the signal and in data compression that would multiply
the data transmitted over the LGA by several orders of magnitude.
Actually the only thing affected by the antenna are the pictures. All of the
scientific data on the probe and just about all of the other instruments
can be supported with the original baud rate of the LGA. There is plenty of
time left over for a minimal number of pictures. Any increase in baud rate
only increases the number of pictures.
I believe that in general, we will get all the scientific data and we will
see at least a couple pictures of everything that they fly past. What we will
miss if the HGA fails to open is seeing multiple pictures taken from many
different angles.
George
|
| 560.715 | I suspect the HGA has to be pretty much completely open before it is useful | DECWIN::FISHER | I *hate* questionnaires--Worf | Tue Jan 05 1993 15:04 | 32 |
| >Question: Isn't a misshapened, partially unfurled antenna better than the LGA
>anyway? can't we do some "Magic" on the receiving end to get better than LGA
>speeds off one of the non-symetrical signal lobes? If the transmitter can't
>slow down enough, how about sending each bit X times and reconstructing from
>the degraded signal?
I think it depends greatly on HOW partially unfurled it is. If I may crudely
draw:
{
{
{
{
{
----------X
{
{
{
{
{
The actually radio wave emitter is at X, and directed back toward the spacecraft.
They reflect off the parabolic shaped dish and are directed toward earth. If the
antenna is not completely open, there are few places on the dish which would have
a parabolic curve, and therefore very little energy reaches earth. If it opens
all the way, but a couple ribs are broken, then most likely one side of the dish
is not strictly parabolic, but a big part of it is, in which case a significant
amount of the expected energy heads in the direction of earth. So I suspect that
they HAVE to get that jackscrew out darn close to the end before the HGA is
useful at all. However, if they break a few ribs on the way, that is ok.
Burns
|
| 560.716 | | FASDER::ASCOLARO | Anthony Edward, 5/5/92 | Wed Jan 06 1993 00:25 | 18 |
| Re George,
Yea, all they miss without the hga is a few pictures :-)
Come on! Those few pictures are really more like movies they miss.
The data rate with the HGA is something like 100-1000X that of the lga.
this applies to compressed and uncompressed data, so you can say they
will use compression to get more data, and better ground antennas, etc,
but really we are still looking at a major loss of data.
And you can bet your bottom dollar that JPL WANTS movies of the Jupiter
system.
Now that having been said, I am more hopefull with this hammering than
I have been for almost 2 years! It looks like they are getting
somewhere. Will it work, or is it enough? I hope so.
Tony
|
| 560.717 | | HELIX::MAIEWSKI | | Wed Jan 06 1993 12:17 | 17 |
| Tony,
I don't think that you disagreed with anything I said even though your tone
sounds like you did.
I said that all they would lose were pictures and I don't think you disagree.
There are a lot more instruments on the probe and orbiter than just the camera
and as far as I've heard, none are effected by the loss of the antenna.
And there will be pictures. They can be recorded on tape and played back
later as the orbiter cruises between moons.
I think we also agree that it would be great if the antenna were deployed
so that we could see all the pictures.
Do we have some sort of debate here?
George
|
| 560.718 | Rathole... | PRAGMA::GRIFFIN | Dave Griffin | Wed Jan 06 1993 12:55 | 40 |
| Re: .714
>> When ever NASA has to do something mechanical they almost always fail.
>> The HGA won't ...
This is, of course, hyperbole.
90% of what NASA "does" is mechanical. If NASA's mechanical systems
almost always failed then we'd have a situation where rockets would NEVER
get off the ground and satellites wouldn't work at all. This is contrary
to the evidence at hand.
They are producing rather complex devices that are generally on a scale
(size) that people just don't internalize well (as far as the forces,
environmental factors, etc. are concerned). Big, complex things break.
You don't have to look at NASA to find plenty of other examples in
history.
NASA's record on software isn't all that hot either (read the reports for
Magellan, HST, and other vehicles. Bad updates, incorrect data, faulty
programs are a dime-a-dozen.
They do seem to have trajectories worked out pretty good -- but that's all
done on the ground, and is generally immune from Murphy.
NASA's record overall is pretty lousy -- but I'm not sure who to benchmark
them against for how it could be done any better (e.g., what other organization
produces essentially unique (one-of-a-kind) devices/vehicles that operate
unattended in microgravity/vacuum/high-temp-flux/radiation-flux?
When I compare their record against, say. mass-produced laser printers I really
can't feel too much distress at their situation (even though I'm never thrilled
with how they manage to spend my tax dollars).
- dave
p.s. We should move this to a separate note if there's more to discuss on the
general topic (as opposed to HGA wailing).
|
| 560.719 | Galileo images available | PRAGMA::GRIFFIN | Dave Griffin | Wed Jan 06 1993 16:18 | 15 |
| Images from the latest flyby, and some background images are now available
from pragma::public:[nasa]
gal_andes
earth_moon
mideast
moon_false
moon_grid
moon_pole
.gif and .info
- dave
p.s. I'd appreciate off-hour access (U.S. ET)
|
| 560.720 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Tue Jan 12 1993 15:33 | 12 |
| The latest Aviation Week says that JPL's hopes for opening the HGA are pretty
much gone. They figured if the first couple sets of hammering did not get it,
it was unlikely to be gotten. However (as has been reported elsewhere) they
will keep trying.
The article also implied (though it was not 100% clear) that the sun-gate changes
may have been because the drive screw did make one additional turn, and that
would have moved the angle of some of the non-stuck ribs to account for the
change. They said it appeared that light also appeared to be going through some
of the antenna mesh before reaching the sensor.
Burns
|
| 560.721 | Updates - January 4-12 | VERGA::KLAES | I, Robot | Tue Jan 12 1993 20:43 | 504 |
| Article: 2777
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 01/04/93
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 5 Jan 1993 01:31:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 4, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Over the holiday period from Wednesday through Sunday, no spacecraft
activity was scheduled. Tracking was scheduled over DSS-43 (Canberra 70
meter antenna).
Today, January 4, 1993, a routine RPM (Retro-Propulsion Module) thruster
flushing maintainence activity is scheduled, and the DDA-5 (Dual-Drive
Actuator #5) Part B memory load is being uplinked. This sequence covers
HGA (High Gain Antenna) warming turn and motor windup and hammering activities
from January 5, 1993 through January 8, 1993. Tracking is scheduled over DSS-43
and DSS-63 (Madrid 70 meter antenna).
Tomorrow, the warming turn to a 34 degree off sun attitude is scheduled
in preparation for the DDA-5 Part B windup and hammering activities.
Real-time commands are scheduled to modify system fault protection parameters.
Tracking is scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2788
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 01/05/93
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Tue, 5 Jan 1993 23:55:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 5, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, a routine RPM (Retro-Propulsion Module) thruster flushing
maintainence activity was performed. The sequence which covers HGA (High
Gain Antenna) warming turn and motor windup and hammering activities from
January 5, 1993 through January 8, 1993 was uplinked, as planned. Tracking
was scheduled over DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid
70 meter antenna).
Today, January 5, 1993, the warming turn to a 34 degree off sun attitude
is scheduled to begin at 12:01 PM PST and complete at 12:26 PM PST. Real-time
commands are also scheduled to modify system fault protection parameters.
Thereafter, real-time motor hammering commands are scheduled to be sent.
Tracking is scheduled over DSS-43.
Tomorrow, real-time motor windup and hammering commands are scheduled
to be sent. Tracking is scheduled over DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2793
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 01/06/93
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 7 Jan 1993 00:40:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 6, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, the warming turn to a 34 degree off sun attitude
began at 12:01 PM PST and was completed at 12:26 PM PST. Real-time
commands were also sent to modify system fault protection parameters.
Thereafter, real-time motor hammering commands were sent. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70
meter antenna).
Today, January 6, 1993, real-time motor hammering commands are scheduled
beign sent. Tracking is scheduled over DSS-43 and DSS-63.
Tomorrow, real-time motor hammering commands may be sent. Specific plans
are being finalized. Tracking is scheduled over DSS-14 (Goldstone 70 meter
antenna), DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2805
Newsgroups: sci.space.news
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 01/07/93
Sender: news@elroy.jpl.nasa.gov (Usenet)
Organization: Jet Propulsion Laboratory
Date: Thu, 7 Jan 1993 18:51:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 7, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, real-time motor hammering commands were sent. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid
70 meter antenna).
Today, January 7, 1993, real-time motor hammering commands are being sent.
Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43 and
DSS-63.
Tomorrow, real-time motor hammering commands are scheduled to be sent.
Tracking is scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2823
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/08/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Sat, 9 Jan 1993 18:24:00 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
December 18, 1992 - January 7, 1993
SPACECRAFT
1. On December 18, real-time commands were sent to disable the system fault
protection thruster flushing all clear response. With the Plasma Detector
(PLS) and the Photopolarimeter-Radiometer (PPR) instruments being turned off,
the thruster flushing all clear response was no longer needed and was disabled
to eliminate unnecessary PPR heater cycles which would otherwise occur during
thruster firing activities.
2. On December 18, real-time commands were sent to enable the Plasma Detector
(PLS) science alarm monitor after it had tripped on November 28 when the PLS
temperature exceeded 35 degrees C. This monitor was reset in order for it to
be functional for the next PLS instrument on time.
3. On December 18, Delayed Action Commands (DACs) were sent to turn the
S-Band ranging on December 19 which is the original background state of EE-11
(Earth-Earth #11 sequence).
4. On December 18, the playback of the Earth/Moon conjunction movie was
completed. This playback consisted of a 14-hour period showing the Moon
passing by as the Earth slowly rotated beneath it. All the data was received
and processed on the ground.
5. On December 18, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
maintenance activity was performed; 10 of the 12 thrusters were "flushed"
during the activity. The P-thrusters were not "flushed" because they were used
to perform SITURN activities on December 16. Spacecraft activity throughout
the period was normal.
6. On December 21, a NO-OP command was sent to reset the command loss timer
to 264 hours, its planned value during this mission phase.
7. On December 22, the Dual Drive Actuator (DDA-5) Turn A sequence memory load
was uplinked to the spacecraft without incident. This sequence covered
spacecraft activities from December 28, 1992 to January 4, 1993 and included a
DDA windup/hammer window opportunity on December 29-30 for approximately 20
hours (see Special Topic No. 2).
8. On December 22, real-time commands were sent to set the command loss timer
to 96 hours. NO-OP commands were sent on December 24 and 26 to reset the
command loss timer to 96 hours, its planned value during this mission phase.
9. On December 28, as part of the DDA-5 Turn A sequence activities, the
warming turn to a 45-degree off-sun attitude started at approximately
1816 UTC and completed at 1854 UTC. After turn completion, real-time commands
were sent to modify the Retro-Propulsion Module (RPM) thermal safing response.
Also, real-time commands were sent to modify the attitude control Fault Monitor
(FM) 2 persistence level from two hours to 55 minutes (see Special Topic No. 2).
10. On December 29, after approximately 20 hours at the warming attitude, the
DDA-5 windup/hammering activities commenced at 1455 UTC. A total of 2160
hammer pulses were executed along with three 20 second windup sequences. Data
analysis indicated the ballscrew rotated approximately 360 degrees for a total
ballscrew rotation beginning with the initial deployment attempt of
approximately 6.4 rotations. There was no indication of a rib release
(see Special Topic No. 2).
11. On December 30, the spacecraft, under stored sequence control, was
commanded back to a 5 degree off-sun attitude at approximately 1048 UTC.
After the sun acquisition, sun gate data was collected to determine if an
antenna rib is still obscuring the sun gate signal. Preliminary data
analysis indicates that the sun gate field of view is still obscured although
the signature appears to have changed. Initial analysis indicates that rib
No. 2 may have moved out to a 43 degree angle. Also, preliminary results may
indicate that the antenna mesh is covering the sun gate field of view.
Additionally, real-time commands were sent to open the star scanner (SS)
shutter, reacquire celestial reference, and select scan type 6 to perform
precise wobble estimation. The wobble estimate indicated a change of 0.3
milliradians which collaborated the motor current data indicating that no
ribs released (see Special Topic No. 2).
12. On December 30, real-time commands were sent to set the command loss timer
to 144 hours, its planned value for this mission phase. On January 4, NO-OP
commands were sent to reset the command loss timer to 144 hours.
13. On January 4, a periodic RPM 10-N thruster maintenance activity was
performed; 10 of the 12 thrusters were "flushed" during the activity. The
P-thrusters were not "flushed" because they are being used during the DDA-5
turn sequence activities. Spacecraft activity throughout the period was
nominal.
14. On January 4, the Dual Drive Actuator (DDA-5) Turn B sequence memory load
was uplinked to the spacecraft without incident. This load set the command
loss timer to 120 hours. This sequence covers spacecraft activities from
January 5, 1993 to January 8, 1993 and includes DDA windup/hammer window
opportunities throughout the period (see Special Topic No. 3).
15. On January 5, as part of the DDA-5 Turn B sequence activities, the warming
turn to a 34-degree off-sun attitude started at approximately 2001 UTC and
completed at 2026 UTC. After the turn completion, real-time commands were
sent to modify the Retro-Propulsion Module (RPM) thermal safing response in
the event of sequence termination. Specifically, the change included turning
the external shunt heaters and bus distribution 2 heaters on while turning off
the NIMS (Near Infrared Mapping Spectrometer) shield heater and despun heaters.
After approximately two hours at the warming attitude, hammering of the
HGA (High Gain Antenna) motors commenced. Five 180 hammer pulse sequences
were sent beginning at 2225 UTC and ending at 0442 UTC. The motor hammering
sequences were executed with the HGA motor temperature at 19.3 degrees C,
29.8 degrees C, 34.4 degrees C, 36.2 degrees C, and 40.6 degrees C.
Preliminary analysis indicated that the ballscrew was stalled with no
appreciable ballscrew rotation. There was some suggestion of minor rotation
with the HGA motor temperature at 29.8 degrees C. There was no indication of
a rib release (see Special Topic No. 3).
16. On January 6, HGA motor hammering started at 1800 UTC. Two 180 hammer
pulse sequences were sent and the activity completed at 1958 UTC. These motor
hammering sequences were executed with the HGA motor temperature at 47.2
degrees C. Data analysis is in process (see Special Topic No. 3).
17. On January 7, two 180 hammer pulse sequences were sent while the HGA
motor temperature was at 47.2 degrees C. Data analysis is in process
(see Special Topic No. 3).
18. The AC/DC bus imbalance measurements exhibited some change. The AC
measurement has ranged from 16DN to 19DN and now reads 18DN (4.1 volts).
The DC measurement has ranged from 62DN (6.9 volts) to 157DN (18.5 volts) and
now reads 150DN (17.7 volts). These measurement variations are consistent
with the model developed by the AC/DC special anomaly team.
19. The Spacecraft status as of January 7, 1993, is as follows:
a) System Power Margin - 16 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.9 rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 32 degrees
off-sun (leading) and 41 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the EUV,
EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 120 hours
Time To Initiation - 118 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Dual Drive Actuator (DDA)-5 Part B sequence memory load was approved
for transmission by the Project on December 30, 1992. This sequence covers
High Gain Antenna (HGA) motor windup/hammering activities from January 5, 1993
through January 8, 1993. Individual sets of hammering/windup commands were
approved as required immediately prior to being uplinked to the spacecraft.
2. The Dual Drive Actuator (DDA-5) Part C sequence memory load was approved
for transmission by the Project on January 7, 1993. This sequence covers
High Gain Antenna (HGA) motor windup/hammering activities from January 11,
1993 to January 14, 1993. As with previous windup/hammering activities,
individual sets of hammering/windup commands will be approved as required
prior to being uplinked to the spacecraft.
GDS:
1. A Galileo MVT (Mission Verification Test) was performed on
December 20, 1992, from 00:00:00 to 05:00:00 GMT, using DSS-12 (Goldstone
34 meter antenna). The purpose of the test was to evaluate the new Station
Communications Processor's (SCP) ability to support Galileo. This test
exercised telemetry, monitor, and command for Galileo. All telemetry rates
were to be tested, however due to resource and time constraints only two rates
were successfully run, (134.4 kbps HRW and 40 bps ESS [uncoded]). The SCP
worked well for the two telemetry rates, monitor, and nominal command portions
of the MVT. Galileo will run all remaining telemetry data rates through the
new SCP interface before any demo passes and/or the SCP is placed in SOAK.
The next available date for a SCP MVT is January 14, 1993.
TRAJECTORY
As of noon Thursday, January 7, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 22,107,500 km (0.15 AU)
Distance from Sun 156,587,900 km (1.05 AU)
Heliocentric Speed 135,300 km per hour
Distance from Jupiter 772,250,300 km
Round Trip Light Time 2 minutes, 30 seconds
SPECIAL TOPIC
1. As of January 7, 1993, a total of 25059 real-time commands have been
transmitted to Galileo since Launch. Of these, 20010 were initiated in the
sequence design process and 5049 initiated in the real-time command process.
In the past three weeks, 16244 real time commands were transmitted: 16242 were
initiated in the sequence design process and 2 initiated in the real time
command process. Major command activities included commands to modify system
fault protection response, enable science alarm monitor, turn S-Band ranging
on, reset the command loss timer, uplink DDA-5A sequence memory load, modify
attitude control fault monitor persistence level, windup and hammer the HGA,
open the star scanner shutter, reacquire celestial reference and select scan
Type 6.
2. The Dual Drive Actuator (DDA) pulse mini-sequence No. 5A covered spacecraft
activities from December 28, 1992 to January 4, 1993. The warming turn to a
45-degree off-sun attitude occurred on December 28. The spacecraft remained at
the warming attitude for approximately 40 hours. The motor windup/hammering
activities began approximately 20 hours at the warming attitude and continued
for 20 hours. A total of 2160 hammer pulses were executed along with three 20
second windup sequences. The sun acquisition back to approximately a 5-degree
off-sun attitude occurred on December 30. Sun gate data was collected on
December 30. The star scanner checkout along with collection of wobble data
was conducted on December 30.
3. The Dual Drive Actuator (DDA) pulse mini-sequence No. 5B covers spacecraft
activities from January 5, 1993 to January 8, 1993. The warming turn to a
34-degree off-sun attitude occurred on January 5, 1993. The spacecraft will
remain at this warming attitude until January 11, 1993 at which time DDA pulse
mini-sequence No. 5C is scheduled to begin. The motor windup/hammering
activities began approximately two hours after reaching the warming attitude.
A total of ten 180 pulse motor hammering sequences are scheduled which will
execute 1800 motor hammering pulses on the spacecraft. The star scanner
checkout along with collection of wobble data is scheduled for January 8, 1993.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2824
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update #2 - 01/08/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Sat, 9 Jan 1993 18:26:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
News-Software: VAX/VMS VNEWS 1.41
GALILEO STATUS REPORT
January 8, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, real-time motor hammering commands were sent. Tracking was
scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43 (Canberra 70 meter
antenna) and DSS-63 (Madrid 70 meter antenna).
Today, January 8, 1993, real-time motor hammering commands are being sent.
Real-time command are also scheduled to reacquire celestial reference.
Thereafter, the next sequence which covers HGA (High Gain Antenna) warming turn
and motor hammering activities from January 11, 1993 through January 13, 1993,
is scheduled to be uplinked. Tracking is scheduled over DSS-14, DSS-43 and
DSS-63.
Over the weekend, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43 and DSS-63.
Keywords: Galileo, JPL
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2833
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/11/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Mon, 11 Jan 1993 19:13:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 11, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna).
Today, January 11, 1993, real-time commands are being sent to update
system fault protection prior to start of the warming turn. The warming turn
to a 45 degree off-sun attitude is scheduled to begin at 11:41 AM PST and
complete at 11:52 AM PST. Real-time commands are then scheduled to modify
the thermal safing response to system fault protection. Real-time motor
hammering commands are then scheduled to be sent. Tracking is scheduled over
DSS-43 and DSS-63 (Madrid 70 meter antenna).
Tomorrow, real-time motor hammering commands are scheduled to be sent.
Tracking is scheduled over DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2836
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/12/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Tue, 12 Jan 1993 19:59:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 12, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, real-time commands were sent to update system fault protection
prior to start of the warming turn. The warming turn to a 45 degree off-sun
attitude began at 11:41 AM PST and completed at 11:52 AM PST. Real-time
commands were then sent to modify the thermal safing response to system fault
protection. Real-time motor hammering commands were then sent. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter
antenna).
Today, January 12, 1993, three 180 pulse hammering pulse sequence using
different hammering frequencies are scheduled prior to the scheduled sun
acquisition to a 5 degree off-sun attitude at 12:13 PM PST. After completion
of the sun acquisition, seven 360 pulse hammering sequences are scheduled.
The 360 pulse hammering sequences combine the previouly used 180 pulse
hammering sequences. Tracking is scheduled over DSS-43 and DSS-63.
Tomorrow, one 360 pulse hammering sequence is scheduled. Real-time
commands to reacquire celestial reference and to update system fault
protection are scheduled. The next sequence which covers HGA warming turn and
motor hammering activities from January 14, 1993, to January 19, 1993, is then
scheduled to be uplinked. Tracking is scheduled over DSS-14 (Goldstone 70
meter antenna), DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
|
| 560.722 | Galileo Chronology Prior to Launch | TINCUP::J_BUTLER | E pur, si muove... | Thu Jan 14 1993 18:48 | 72 |
| Article 55076 of sci.space:
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From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro,alt.sci.planetary
Subject: Galileo's History (Was Re: Galileo Stuck Ribs / Remote Manipulator?)
Date: 14 Jan 1993 19:43 UT
Organization: Jet Propulsion Laboratory
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References: <C0tBAt.8un@zoo.toronto.edu> <justin.726989647@mik.uky.edu> <20999@ksr.com> <1993Jan14.161958.10711@gn.ecn.purdue.edu>
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In article <1993Jan14.161958.10711@gn.ecn.purdue.edu>, mechalas@gn.ecn.purdue.edu (John P. Mechalas) writes...
>...you'd be amazed at what the designers of Galileo had to put up
>with...it's amazing the program is still alive.
That's an understatement. Here's a history of what the Galileo mission had
to go through before it was finally launched.
1975 - NASA decides that the proposed Jupiter Orbiter Mission (JOM)
will be the first planetary spacecraft launched on the Space Shuttle.
The mission was later renamed to Galileo.
1977 - Congress nearly cancels the Galileo program, but it survives and
is approved for launch in 1982 and arrival in 1985. A new IUS
(Interim Upper Stage) is to be built that will propel Galileo
directly to Jupiter.
1980 - The Space Shuttle program falls far behind schedule and Galileo's
launch is slipped to 1984 with arrival delayed until 1986. Since the
1984 trajectory is unfavorable NASA decides on a major engineering
change. The spacecraft is split in two, an orbiter section and an
atmospheric probe section, and are to be launched separately. The
spacecraft and the mission are completely redesigned.
1981 - The IUS (now cleverly renamed to Inertial Upper Stage) cannot meet
its design specs and cannot propel Galileo directly to Jupiter.
NASA opts for the more powerful liquid fueled Centaur stage.
The probe and orbiter are recombined for a single launch, and the
spacecraft and mission are redesigned once again. The launch date is
slipped to 1985.
1982 - David Stockman cancels the Galileo program. The program is restored
by Congress.
1984 - Problems with the Space Shuttle and Centaur delay the launch again
to 1986 with arrival in 1988.
1986 - Challenger explodes just four months before Galileo was to have
been launched. The Centaur program is cancelled for safety reasons.
Without a launch vehicle to get the spacecraft to Jupiter, the
mission is once again on the verge of cancellation.
1987 - The VEEGA trajectory is developed and can get Galileo to Jupiter
using the IUS. Galileo is scheduled again for launch in 1989.
Cruise time to Jupiter with the VEEGA trajectory is six years.
Arrival time is late 1995, ten years after the original arrival date.
1989 - Galileo is finally launched from the Space Shuttle with the IUS.
___ ______ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
|
| 560.723 | Updates - January 13-15 | VERGA::KLAES | I, Robot | Fri Jan 15 1993 19:23 | 246 |
| Article: 2844
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/13/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Wed, 13 Jan 1993 18:15:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 13, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, three 180 pulse hammering pulse sequences using
different hammering frequencies were sent prior to the scheduled sun
acquisition to a 5 degree off-sun attitude at 12:13 PM PST. After completion
of the sun acquisition, seven 360 pulse hammering sequences were sent.
The 360 pulse hammering sequences combine the previouly used 180 pulse
hammering sequences. Tracking is scheduled over DSS-43 (Canberra 70 meter
antenna) and DSS-63 (Madrid 70 meter antenna).
Today, January 13, 1993, one 360 pulse hammering sequence is scheduled.
Real-time commands to reacquire celestial reference and to update system fault
protection are scheduled. The next sequence which covers HGA (High Gain
Antenna) warming turn and motor hammering activities from January 14, 1993,
to January 17, 1993, is then scheduled to be uplinked. Tracking is scheduled
over DSS-14 (Goldstone 70 meter antenna), DSS-43 and DSS-63.
Tomorrow, the warming turn to a 26 degree off-sun attitude is scheduled
to begin at 12:02 PM PST and complete at 12:17 PM PST. Real-time commands are
then scheduled to update system fault protection parameters. Seven 360 pulse
hammer sequences are then scheduled to be sent. Tracking is scheduled over
DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2859
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/14/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Thu, 14 Jan 1993 22:09:00 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
January 8 - 14, 1993
SPACECRAFT
1. On January 8, one 180 hammer pulse sequence was sent while the HGA (High
Gain Antenna) motor temperature was at 45.0 degrees C. This hammer sequence
utilized a pulse duration of 0.267 seconds with a 33.3 percent duty cycle
(1.25 hertz).
2. On January 8, real-time commands were sent to reacquire celestial
reference at the completion of the star scanner checkout.
3. On January 8, the Dual Drive Actuator (DDA-5) Turn C sequence memory load
was uplinked to the spacecraft without incident. This sequence covers
spacecraft activities from January 11, 1993 through January 13, 1993 and
includes DDA hammer window opportunities throughout the period.
4. On January 9, Delayed Action Commands (DACs) were sent to turn the gyro
heaters on January 11 for approximately one hour to ensure the gyro
temperatures are above 5 degrees C (minimum 3-210 gyro operating limit) for
the scheduled warming turn later in the day.
5. On January 11, prior to the execution of the warming turn, real-time
commands were sent to update the system fault protection AACS-INIT-SLOT to the
sun. This change will cause the spacecraft to point towards the sun in the
event of an AACS (Attitude and Articulation Control Subsystem) Power On Reset
(POR).
6. On January 11, as part of the DDA-5 Turn C sequence activities, the
warming turn to a 45-degree off-sun attitude started at approximately
1941 UTC and completed at 1952 UTC. After turn completion, real-time commands
were sent to modify the Retro-Propulsion Module (RPM) thermal safing response
in the event of sequence termination.
After approximately one hour at the warming attitude, hammering of the
HGA motors commenced. Five 180 hammer pulse sequences were sent beginning at
2100 UTC and ending at 0111 UTC. The motor hammering sequences were executed
with the HGA motor temperature at 42.8 degrees C. These hammer sequences
utilized a pulse duration of 0.267 seconds with a 33.3 percent duty cycle
(1.25 hertz).
7. On January 12, three 180 pulse hammer sequences were sent prior to the
sun acquisition when the HGA motor temperature was at 45.0 degrees C. These
hammer sequences utilized a pulse duration of 0.267 seconds with a 50 percent
duty cycle (1.875 hertz).
The sun acquisition to a 5-degree off-sun attitude began at approximately
2013 UTC and completed at 2043 UTC. Approximately one hour later, a series of
seven 360 pulse hammer sequences were sent beginning at 2130 UTC and ending at
0439 UTC. These hammer sequences utilized two different hammer frequencies;
one with a pulse duration of 0.267 seconds with a 33.3 percent duty cycle
(1.25 hertz), and the other with a pulse duration of 0.267 seconds with a
50 percent duty cycle (1.875 hertz). These motor hammering sequences were
executed with the HGA motor temperature at 38.4 degrees C, 34.0 degrees C,
27.6 degrees C, 25.5 degree C, 21.4 degrees C, 19.3 degrees C, and 15.2
degrees C.
8. On January 13, one 360 pulse hammer sequence was executed with the HGA
motor temperature at 5.2 degrees C. Then real-time commands were sent to
reacquire celestial reference and select Scan Type 6 for the collection of
precise wobble data. The analysis of the wobble data is currently in progress.
Real-time commands were then sent to update the System Fault Protection (SFP)
AACS-INIT-SLOT to Earth in preparation for the DDA-5 Turn D sequence
activities.
9. On January 13, the Dual Drive Actuator (DDA-5) Turn D sequence memory load
was uplinked to the spacecraft without incident. This sequence covers
spacecraft activities from January 14, 1993 to January 17, 1993 and includes
DDA hammer window opportunities throughout the period.
10. On January 14, as part of the DDA-5 Turn D sequence activities, the
warming turn to a 26-degree off-sun attitude started at approximately 2002 UTC
and completed at 2017 UTC. After the turn completion, real-time commands
were sent to modify the Retro-Propulsion (RPM) thermal safing response in the
event of sequence termination.
After approximately two hours at the warming attitude, hammering of the
HGA motors commenced using the two different frequencies (1.25 hertz and
1.875 hertz). Seven 360 pulse hammer sequences are being sent beginning at
2200 UTC and are in progress at the time of this writing.
Motor current profiles throughout this reporting period indicate
minuscule ballscrew rotation on occasional, random pulses. There has been no
substantial rotation since the major hammering on December 29, 1992.
11. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18DN
(4.1 volts). The DC measurement reads 151DN (17.8 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
12. The Spacecraft status as of January 14, 1993, is as follows:
a) System Power Margin - 23 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.9rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 26 degrees
off-sun (leading) and 40 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the EUV,
EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 120 hours
Time To Initiation - 120 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Dual Drive Actuator (DDA-5) Part D sequence memory load was approved
for transmission by the Project on January 12, 1993. This sequence covers
High Gain Antenna (HGA) motor hammering activities from January 14, 1993 to
January 17, 1993. As with previous hammering activities, individual sets of
hammering commands will be approved as required prior to being uplinked to the
spacecraft.
2. The EE-12 (Earth-Earth #12) Final Sequence and Command Generation products
were approved by the Project on January 12, 1993. This sequence covers
spacecraft activities from January 20, 1993 to January 23, 1993 and from
February 8, 1993 to April 12, 1993.
TRAJECTORY
As of noon Thursday, January 14, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 26,870,100 km (0.18 AU)
Distance from Sun 162,207,200 km (1.09 AU)
Heliocentric Speed 132,400 km per hour
Distance from Jupiter 751,299,000 km
Round Trip Light Time 3 minutes, 0 seconds
SPECIAL TOPIC
1. As of January 14, 1993, a total of 45639 real-time commands have been
transmitted to Galileo since Launch. Of these, 40586 were initiated in the
sequence design process and 5053 initiated in the real-time command process.
In the past week, 19773 real time commands were transmitted: 19769 were
initiated in the sequence design process and 4 initiated in the real time
command process. Major command activities included commands to hammer the
HGA motors, reacquire celestial reference, uplink DDA-5C sequence memory load,
turn the gyro heaters on, update system fault protection, modify RPM thermal
safing response, select Scan Type 6, and uplink DDA-5D sequence memory load.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
Article: 2867
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/15/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Fri, 15 Jan 1993 18:20:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 15, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, the warming turn to a 26 degree off-sun attitude began
at 12:02 PM PST and completed at 12:17 PM PST. Real-time commands were
then sent to update system fault protection parameters. Seven 360 pulse
hammer sequences were then sent. Tracking was scheduled over
DSS-14 (Goldstone 70 meter antenna), DSS-43 (Canberra 70 meter antenna)
and DSS-63 (Madrid 70 meter antenna).
Today, January 15, 1993, the next sequence which covers the HGA (High
Gain Antenna) warming turn and motor hammering activities from
January 18, 1993, to January 20, 1993, is being uplinked. One 360 pulse
hammer sequence is then scheduled to be sent. Tracking is scheduled over
DSS-43.
Over the weekend, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Choose a job you love, and
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/ |_|/ |_____|/ | a day in your life.
|
| 560.724 | Gaspra images references | VERGA::KLAES | I, Robot | Mon Jan 18 1993 17:23 | 27 |
| Article: 30747
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.astro,sci.space
Subject: Re: GASPRA article in Jan. 1 Science
Date: 18 Jan 1993 16:51 UT
Organization: Jet Propulsion Laboratory
In article <1993Jan18.074128.1@sscl.uwo.ca>, stooke@sscl.uwo.ca writes...
>There is a nice (but brief) article on Gaspra in the Jan. 1 issue
>of SCIENCE - editorial section, not a science team report, but it
>includes a nice montage of images showing almost a full rotation...
The same images are also shown on the cover of the January 5 issue of
EOS. The montage consists of 11 images, with the smallest image taken
when Galileo was 164,000 km from the asteroid (6 hours prior to
closest approach), and the best image was taken from a distance of
16,000 km (30 minutes from closest approach). Gaspra rotates about
every 7 hours.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
|
| 560.725 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Wed Jan 20 1993 20:14 | 6 |
| JPL has finished hammering the Galileo HGA, with still no luck. The only thing
else that they will try before giving up is spinning up the s/c to 10 RPM (don't
know if they will try hammering while it is spinning or not). But they don't
believe it is likely to work.
Burns
|
| 560.726 | dreaming | AUSSIE::GARSON | | Wed Jan 20 1993 23:48 | 8 |
| re .-1
Perhaps one day someone on an interplanetary freighter arriving at
Jupiter will hop into a pod and go take a look so we will know
definitively what went wrong and satisfy my curiosity...which leads me
to ask what the long term prognosis for Galileo is i.e. when is nominal
end of mission? where is the craft going to be "parked" afterwards?
what is expected life of propellant? RTGs?
|
| 560.727 | | DECWIN::FISHER | I *hate* questionnaires--Worf | Thu Jan 21 1993 15:48 | 8 |
| I don't know the answers to your questions. However, given that its orbit is
planned to allow examination of several moons, I would guess that it is probably
within the gravitational influence of several moons and would probably get
jerked around quite a bit. I don't know if that would lead to a likely early
demise, or if it would be more likely just to find a stable orbit that did not
resonate with nearby moons.
Burns
|
| 560.728 | RE 560.726 | VERGA::KLAES | I, Robot | Thu Jan 21 1993 18:06 | 8 |
| There was an old article in CANOPUS (See Topic 335) which discussed
one option for the end of GALILEO: Send it crashing into the moon Io.
Why they wanted to do this it did not say. Perhaps to get some closeup
data before the probe is destroyed, like the RANGER 6-9 series did with
Luna back in 1964-1965?
Larry
|
| 560.729 | | HELIX::MAIEWSKI | | Fri Jan 22 1993 20:10 | 9 |
| I can see it now. Galileo comes flashing down in a blur ***CRASH*** right
next to a volcano on Io with parts flying off in every direction. Most of the
craft is demolished beyond recognition with the exception of one part thrown
miraculously off to the side which lands ***THUNK*** on the ground.
Suddenly .... *** POP *** TWANG *** ... and the High Gain Antenna pops open
and sits fully deployed on a flat rock surface.
George
|
| 560.730 | Good one... | VIDEO::WALL | | Mon Jan 25 1993 14:42 | 3 |
|
Well at least it survived the shock and vibration test ;- )
|
| 560.731 | | CXDOCS::J_BUTLER | E pur, si mouve... | Mon Jan 25 1993 18:07 | 4 |
| Someone tell Gary Larson...I be he'd make a good Far Side panel out of
_that_ scenario!
jb
|
| 560.732 | Galileo Laser Test Successful | PRAGMA::GRIFFIN | Dave Griffin | Mon Jan 25 1993 21:43 | 132 |
| From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Date: 23 Jan 1993 06:33 UT
Organization: Jet Propulsion Laboratory
From the "JPL Universe"
December 30, 1992
GOPEX reaches Galileo via laser beam
By Mark Whalen
JPL researchers took advantage of Galileo's recent pass by
Earth to achieve a major milestone in space communications, by
successfully transmitting laser beams fired from the ground to
the spacecraft at distances of up to 6 million kilometers (3.7
million miles).
"This experiment is part of a program to show that future
deep space missions can use laser beams to send back to Earth
larger volumes of space-acquired data than is currently possible
using radio signals," said Dr. James Lesh, supervisor of the
Optical Communications Group and principal investigator for the
Galileo Optical Experiment (GOPEX).
The experiment's objectives, said Lesh, were to show that an
uplink beacon laser -- required as a reference for pointing a
return beam back to Earth -- could be successfully pointed to a
distant spacecraft based only on the navigational predicts of the
spacecraft trajectory. To do this, the distortions produced by
Earth's atmosphere had to be predicted and accommodated.
The GOPEX demonstration began on Dec. 9 (one day after
Galileo made its closest Earth approach on its way to Jupiter) at
600,000 kilometers (370,000 miles), and continued through Dec.
16. Laser beams were simultaneously transmitted to the spacecraft
from a 61-centimeter (24-inch-diameter) telescope at the Table
Mountain Observatory near Wrightwood, Calif. and from a 1.5-meter
(60-inch) telescope at the U.S. Air Force Phillips Laboratory's
Starfire Optical Range near Albuquerque, N.M.
The transmissions, which were detected by Galileo's onboard
camera, established a record for the farthest known transmission
and reception of a laser beam, a final distance of 6 million
kilometers.
"GOPEX was extremely successful," said Lesh. "A real
pleasant surprise in the experiment was that we conducted the
experiment so repeatedly. Each day we made transmissions, we had
extremely reliable detections on the spacecraft camera.
"We would predict ahead of time, `on this frame, we're going
to see a series of pulses about so high on the picture,' and as
soon as we got the image back, sure enough, there they were," he
said.
Spacecraft signals produced by current radio-frequency
systems are used for three purposes, according to Lesh --
communications, navigation and science investigations. "There are
completely analogous applications in the laser area," he said.
"We can communicate at substantially higher rates while
occupying much less room on the spacecraft," said Lesh. "The
antenna is the main feature on the spacecraft with radio
frequencies, often reaching diameters in excess of four meters.
At laser frequencies, 10-50 centimeter telescopes are quite
adequate.
"We can also use optical beams for navigation," Lesh
continued. "When viewed from Earth, the light beam from a
spacecraft will look like a blinking star. We can view it in the
context of the stellar grid, or relative to target bodies we are
approaching. That information can be used to derive angular
coordinates of the spacecraft.
"Laser signals also can be used to determine the
spacecraft's range, which, together with the angle information,
can be used to locate the spacecraft," said Lesh.
As far as science investigations are concerned, Lesh claims
that scientists could use optical signals to probe phenomena such
as planetary atmospheres, to measure scattering from the
interplanetary dust particle distribution, or to make spatially
selective measurements of planetary ring systems using very short
wavelengths (below one micron).
"Also," Lesh added, "optical signals are not corrupted by
solar wind fluctuations, like radio frequencies are. Some past
investigations of gravitational bending of radio waves have been
limited by charged particle fluctuations in the solar wind."
Lesh also said laser communications technology will yield a
data rate increase "of about one-to-two orders of magnitude" over
radio frequencies.
The idea of testing a laser uplink is not a new one. Lesh
said that the GOPEX demonstration was originally proposed in June
1984, but was rejected at the time because there were no plans
for Galileo to view Earth on its way to Jupiter.
But the 1986 Space Shuttle Challenger accident prompted
changes in Galileo's launch system and necessitated a new flight
path, which included two gravity-assisted flybys of Earth. "At
the same time," he said, "Earth viewing became part of Galileo's
priorities, and the climate became much more receptive to our
doing the experiment, subject to us demonstrating beyond any
doubt that we would not damage any instrument on board the
spacecraft."
In that regard, preperations were made to conduct GOPEX
during the Earth-1 encounter in December 1990. But inconclusive
data turned up on a test to determine if the experiment might
harm the Galileo orbiter's Near-Infrared Mapping Spectrometer, so
"about three days before the experiment, we were waved off," said
Lesh. In the intervening two years, testing of the effects of
laser signals on the NIMS and Solid State Imaging Camera
detectors concluded that "we were safe to substantially higher
levels than we would ever produce at the spacecraft," said Lesh.
What's next for the program? Lesh said proposed plans call
for a flight experimental terminal to be flown aboard a space
shuttle in the latter half of the 1990s. "We are developing the
base technology for this now," he said, "and are trying to
augment the base program with some new flight experiment monies
that will allow us to do the (shuttle) demonstration."
Operational use of this technology is anticipated some time
after the year 2000, Lesh added.
"We expect that the first deep space mission to fly optical
will fly it as a mission enhancement experiment," said Lesh,
"although this could change with the new emphasis on low-cost
microspacecraft.
"I believe that there are missions that can be best served
by laser frequencies, and there are those that are best served by
radio frequencies," he said. "Laser beams do require a certain
amount of pointing, for example. If you have large uncertainty
about the spacecraft pointing direction, it may be better to use
radio waves. However, most missions currently flying or on the
drawing boards provide adequate attitude control to use laser
communications.
"Nevertheless," said Lesh, "I don't see us de-implementing
any capabilities in the future; I see us providing an additional
capability that will allow future missions to plan for and make
best use of the available technologies."
###
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
|
| 560.733 | Updates - January 18-25 | VERGA::KLAES | I, Robot | Tue Jan 26 1993 17:18 | 362 |
| Article: 2884
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 01/18/93
Date: 18 Jan 93 22:45:00 GMT
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 18, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna).
Today, January 18, 1993, one 360 pulse hammer sequence has been sent.
Real-time commands to reacquire celestial reference has also been
transmitted. The EE-12A (Earth-Earth 12) sequence memory load which covers
spacecraft activities from January 20 to January 23 is also scheduled to be
uplinked. Tracking is scheduled over DSS-43.
Tomorrow, the turn to a 9 degree off-Sun attitude is scheduled to begin
at 10:02 AM PST and complete at 10:22 AM PST. Approximately one hour later,
real-time commands are scheduled to continue the HGA (High Gain Antenna)
motor hammering pulse. Real-time commands to reacquire celestial reference
are also scheduled. Tracking is scheduled over DSS-43 and DSS-63 (Madrid
70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
Article: 2894
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/19/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Tue, 19 Jan 1993 18:21:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 19, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, one 360 pulse hammer sequence was sent. Real-time commands
to reacquire celestial reference were also transmitted. The EE-12A
(Earth-Earth #12) sequence memory load which covers spacecraft activities
from January 20 to January 23 was also uplinked. Tracking was scheduled
over DSS-43 (Canberra 70 meter antenna).
Today, January 19, 1993, the turn to a 9 degree off-Sun attitude is
scheduled to begin at 10:02 AM PST and complete at 10:22 AM PST.
Approximately one hour later, real-time commands are scheduled to continue
the HGA (High Gain Antenna) motor hammering pulses. Real-time commands to
reacquire celestial reference are also scheduled. Tracking is scheduled over
DSS-43 and DSS-63 (Madrid 70 meter antenna).
Tomorrow, a routine RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity and SITURN are scheduled. Tracking is
scheduled over DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
Article: 2904
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/20/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Wed, 20 Jan 1993 18:01:00 GMT
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
January 20, 1993
The Galileo spacecraft is almost 31 million kilometers, or
about 19.2 million miles, from the Earth, receding at more than a
quarter of a million miles each day. It is 1.12 astronomical
units (104.3 million miles) from the Sun, and has traveled almost
2.6 billion kilometers (1.6 billion miles) since launch, or two-
thirds of its total path to Jupiter.
The spacecraft is in the dual-spin mode, spinning at just
over 3 rpm with the lower part fixed in orientation. It is
transmitting coded telemetry at 1200 bits per second over the
low-gain antenna. Except for the fact that the high-gain antenna
remains undeployed, Galileo's health and performance are excellent.
Yesterday the flight team sent commands to pulse the antenna
deploy motors 1800 times, concluding ten days of motor hammering
this year. Counting the hammering session of December 29-30,
1992, a total of 13,320 pulses have been executed in the latest
attempt to free the three stuck antenna ribs. Although there has
been some motion in the deployment system and in the antenna, the
ribs have not yet been freed. The last remaining action in the
plan for the stuck antenna is to spin up the spacecraft to 10 rpm
in March; there is little expectation that this will help. Very
shortly the Project plans to focus on doing the Galileo mission
with the low-gain antenna.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
Article: 2913
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/21/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Thu, 21 Jan 1993 22:46:00 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
January 15 - 21, 1993
SPACECRAFT
1. On January 15, the Dual Drive Actuator (DDA-5) Turn E sequence memory load
was uplinked to the spacecraft without incident. This sequence covers
spacecraft activities from January 18, 1993 through January 20, 1993 and
includes DDA hammer window opportunities throughout the period.
2. On January 15, one 360 pulse hammer sequence was executed with the HGA
(High Gain Antenna) motor temperature at 36.2 degrees C. This hammer sequence
utilized two different hammer frequencies (1.25 hertz and 1.875 hertz).
3. On January 18, one 360 pulse hammer sequence was executed with the HGA
motor temperature at 34.0 degrees C. This hammer sequence utilized two
different hammer frequencies (1.25 hertz and 1.875 hertz). Real-time commands
were then sent to reacquire celestial reference at the completion of the star
scanner checkout.
4. On January 18, the EE-12A (Earth-Earth #12A) sequence memory load was
uplinked to the spacecraft without incident. This sequence covers spacecraft
activities from January 20, 1993 through January 23, 1993.
5. On January 19, as part of DDA-5 Turn E sequence activities, the turn to a
9-degree off-sun attitude started at approximately 1802 UTC and completed at
1822 UTC. After approximately one hour at the new attitude, hammering of the
HGA motors commenced. Five 360 hammer pulse sequences were sent beginning at
1935 UTC and ending at 2349 UTC. The motor hammering sequences were executed
with the HGA motor temperature at 25.5 degrees C, 21.4 degrees C,
19.3 degrees C, 17.2 degrees C, and 15.2 degrees C. These hammer sequences
utilized two different hammer frequencies (1.25 hertz and 1.875 hertz). There
continues to be no substantial ballscrew rotation since the major hammering on
December 29, 1992. Approximately 5 hours after the motor hammering activity
terminated, real-time commands were sent to reacquire celestial reference after
the star scanner checkout completed.
6. On January 20, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
maintenance activity was performed; all 12 thrusters were "flushed" during the
activity. Spacecraft activity throughout the period was normal.
7. On January 20, a SITURN was scheduled in the EE-12 sequence. The
purpose of the SITURN was to ensure the spacecraft was at the EE-12
attitude in the event that the DDA-5 Turn E sequence was not executed
on the spacecraft.
8. During the period from January 20 through January 21, a navigation cycle
was performed. This navigation cycle provided near-continuous acquisition of
two-way doppler and ranging data during four consecutive passes of the
spacecraft over DSS-43 (Canberra 70 meter antenna), DSS-63 (Madrid 70 meter
antenna), DSS-14 (Goldstone 70 meter antenna), and then back to DSS-43.
9. On January 20, real-time commands were sent to enable the master critical
enable and to lift AACS (Attitude and Articulation Control Subsystem) write
protects in preparation for the sequence controlled Clock System Identification
(CLKSYSID) activity. Upon completion of the CLKSYSID, real-time commands were
then sent to restore the AACS write protects and to disable the master
critical enable.
10. On January 21, Cruise Science Memory Readouts (MROs) were
performed for the Extreme Ultraviolet Spectrometer (EUV). Preliminary
analysis indicates the data was received properly.
11. On January 21, numerous attitude control subsystem calibrations were
performed including a Star Scanner A calibration, wobble identification, gyro
drift calibration, spin detector A calibration, Spin Bearing Assembly (SBA)
drag torque calibration, accelerometer calibration, and a Scan Actuator
Subassembly (SAS) friction test. The data was collected nominally and
analysis is in progress.
12. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18DN
(4.1 volts). The DC measurement reads 153DN (18.0 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
13. The Spacecraft status as of January 21, 1993, is as follows:
a) System Power Margin - 74 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 8 degrees
off-sun (leading) and 39 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the EUV,
EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within acceptable range
j) CMD Loss Timer Setting - 120 hours
Time To Initiation - 96 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Dual Drive Actuator (DDA-5) Part E sequence memory load was approved
for transmission by the Project on January 15, 1993. This sequence covered
High Gain Antenna (HGA) motor hammering activities from January 18, 1993 to
January 20, 1993. As with previous hammering activities, individual sets of
hammering commands were approved as required prior to being uplinked to the
spacecraft.
2. The EJ-1 (Earth-Jupiter #1) Cruise Plan was approved by the Project on
January 19, 1993. This plan covers spacecraft activities from April 12, 1993
to June 15, 1993.
GDS (Ground Data Systems):
1. A Galileo MVT (Mission Verification Test) was performed on January 14, 1993,
using DSS-14 (Goldstone). The purpose of the test was to evaluate the new
Station Communications Processor's (SCP) ability to support Galileo. This test
exercised telemetry and monitor for Galileo. The SCP worked well for all
Galileo telemetry rates and monitor. Two liens were identified during MVT
testing: (1) unable to perform dual stream 134.4 kbps data test due to
unavailability of DSN (Deep Space Network) resources; (2) unable to use MCCC
(Mission Control and Computing Center) SIM long loop due to ARAs (Area Routing
Assembly) being prime. These liens will be demonstrated as working in SOAK by
performing GDS tests on the specific lien. The SCP is expected to go into SOAK
for Galileo support on February 5, 1993.
TRAJECTORY
As of noon Thursday, January 21, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 31,623,600 km (0.21 AU)
Distance from Sun 168,800,400 km (1.13 AU)
Heliocentric Speed 129,300 km per hour
Distance from Jupiter 730,891,900 km
Round Trip Light Time 3 minutes, 32 seconds
SPECIAL TOPIC
1. As of January 21, 1993, a total of 64682 real-time commands have been
transmitted to Galileo since Launch. Of these, 59329 were initiated in the
sequence design process and 5053 initiated in the real-time command process.
In the past week, 18743 real time commands were transmitted: 18743 were
initiated in the sequence design process and none initiated in the real time
command process. Major command activities included commands to uplink DDA-5E
sequence memory load, hammer the HGA motors, reacquire celestial reference,
uplink the EE-12A sequence memory load, and perform CLKSYSID activities.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
Article: 2919
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/22/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Sat, 23 Jan 1993 06:29:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 22, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, AACS (Attitude and Articultion Control Subsystem)
calibrations were performed, as planned. Tracking was scheduled over DSS-14
(Goldstone 70 meter antenna) and DSS-43 (Canberra 70 meter antenna).
Today, January 22, 1993, real-time commands were sent to power cycle the
UVS (Ultraviolet Spectrometer) on/off to exercise the drive mechanism.
Real-time commands are also scheduled to perform planned system fault
protection updates. Stored sequence planned cruise science MROs (Memory
Readouts) were completed as scheduled. Also, the planned USO (Ultra Stable
Oscillator) test was performed. The PWS (Plasma Wave) instrument is also
scheduled to be turned on from the stored sequence. Tracking is scheduled
over DSS-43.
Over the weekend, no spacecraft activity or tracking is scheduled.
The AACS inflight mode is scheduled to begin on Monday, January 25, 1993.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
Article: 2935
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/25/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Tue, 26 Jan 1993 01:57:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 25, 1993
The Galileo Spacecraft is operating normally in the all-spin mode at
2.9 rpm, and is transmitting coded telemetry at 1200 bps (bits/second).
Over the weekend, no spacecraft activity or tracking was scheduled.
Today, January 25, 1993, the AACS (Attitude and Articulation Control
Subsystem) inflight mode related activites have begun and are proceeding
nominally. Tracking is scheduled DSS-14 (Goldstone 70 meter antenna),
DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Tomorrow, the AACS inflight mode related activities will continue with
a nominal completion date of January 29, 1993. Tracking is scheduled
over DSS-14, DSS-43 and DSS-63
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
|
| 560.734 | | FASDER::ASCOLARO | Anthony Edward, 5/5/92 | Tue Jan 26 1993 23:10 | 10 |
| Is there any reason they cannot hammer all the way to Jupiter?
Seems like there continues to be SOME (albeit limited) 'ballscrew
rotation'. Seems to me that with 2.5 years to go they could settle for
some rotation. Might pass a critical point at any time. You guys know
what I mean, if you have ever changed a tire. At some point, the nut
gets dramatically easier to turn. Am I way off base on this? Or is it
possible that it could open at any time?
Tony
|
| 560.735 | Galileo Update -- 01/26/93 | PONIL::J_BUTLER | E pur, si muove... | Wed Jan 27 1993 12:58 | 46 |
| Article 2944 of sci.space.news:
Newsgroups: sci.space.news
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/26/93
Message-ID: <27JAN199301152610@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 26, 1993
The Galileo Spacecraft is operating normally in the all-spin mode at
2.9 rpm, and is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, the AACS (Attitude and Articulation Control Subsystem)
in-flight mode related activites began and proceeded nominally. Tracking was
scheduled DSS-14 (Goldstone 70 meter antenna), DSS-43 (Canberra 70 meter
antenna) and DSS-63 (Madrid 70 meter antenna).
Today, January 26, 1993, the AACS in-flight mode related activities are
continuing with a nominal completion date of January 29, 1993. Tracking is
scheduled over DSS-14, DSS-43 and DSS-63
Tomorrow, the AACS in-flight mode related activities will continue with
the loading of the memory A with AACS 12.0 flight software, as scheduled.
Tracking is scheduled over DSS-14, DSS-43 and DSS-63
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
|
| 560.736 | | HELIX::MAIEWSKI | | Wed Jan 27 1993 13:29 | 16 |
| As I understand, the ballscrew rotation that they saw was due to the fact
that they bent the ribs as far as they could by hammering. None of the stuck
ribs released. According to their calculations they don't fell they can bend
the ribs any more. If they do keep hammering it would be to either pop one or
more ribs loose or to break one or more ribs.
They have obviously come up with models of what might be wrong and it may be
that by hammering they have eliminated some of the easier to fix choices. It
could be that their calculations show that none of the models that are left
will respond to hammering alone.
The other factor in down playing the hammering is that it seems that they are
increasing their confidence in what can be accomplished with the low gain
antenna.
George
|
| 560.737 | Galileo Update -- 01/27/93 | PONIL::J_BUTLER | E pur, si muove... | Fri Jan 29 1993 13:10 | 47 |
| Article 2952 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!caen!spool.mu.edu!agate!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/27/93
Message-ID: <28JAN199301151469@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 27, 1993
The Galileo Spacecraft is operating normally in the all-spin mode at
2.9 rpm, and is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, the AACS (Attitude and Articulation Control Subsystem)
in-flight mode related activities continued with a nominal completion date of
January 29, 1993. Tracking was scheduled over DSS-14 (Goldstone 70 meter
antenna), DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter
antenna).
Today, January 27, 1993, the AACS in-flight mode related activities are
continuing with the loading of the memory A with AACS 12.0 flight software in
progress. Tracking is scheduled over DSS-14, DSS-43 and DSS-63
Tomorrow, the AACS in-flight mode related activities will continue
with the loading of memory B with AACS 12.0 flight software scheduled.
Tracking is scheduled over DSS-14, DSS-43 and DSS-63
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
|
| 560.738 | Galileo Update -- 01/28/93 | PONIL::J_BUTLER | E pur, si muove... | Fri Jan 29 1993 13:12 | 49 |
| Article 2960 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!decwrl!purdue!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/28/93
Message-ID: <29JAN199302204644@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Fri, 29 Jan 1993 02:20:00 GMT
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Lines: 30
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 28, 1993
The Galileo Spacecraft appears to be operating normally in the all-spin
mode at 2.9 rpm, and is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, the AACS (Attitude and Articulation Control Subsystem)
in-flight mode related activities continued with the loading of the memory A
with the AACS 12.0 flight software completed, as planned. Tracking is
scheduled over DSS-14 (Goldstone 70 meter antenna), DSS-43 (Canberra 70 meter
antenna) and DSS-63 (Madrid 70 meter antenna).
Today, January 28, 1993, after swapping to memory A with the AACS 12.0
flight software, an anomaly occurred that indicated that the scan platform was
slewed. Loading of memory B with AACS 12.0 flight software has been temporarily
suspended pending investigation of this anomaly. Tracking is scheduled over
DSS-14, DSS-43 and DSS-63.
Tomorrow, loading of memory B with the AACS 12.0 flight software is
scheduled to continue pending the results of the anomaly investigation.
Tracking is scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
|
| 560.739 | I figured I'd post this direct reply | 3D::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Fri Jan 29 1993 13:33 | 20 |
| I had some questions about whether the relay satellite mission was being
persued in the background. The following response is what I recieved back.
Jim,
There will be no relay satellite for Galileo. There will be a spinup
test in March, but after that we have an encounter with an asteroid to
take of.
Ron Baalke
% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% Received: by enet-gw.pa.dec.com; id AA03579; Wed, 27 Jan 93 21:12:52 -0800
% Date: Thu, 28 Jan 1993 5:11:47 GMT+0000
% From: BAALKE@KELVIN.JPL.NASA.GOV (Ron Baalke)
% Message-Id: <930128051147.24c04379@KELVIN.JPL.NASA.GOV>
% Subject: RE: Galileo antenna problem. What remains?
% To: 3d::reith
% X-Vmsmail-To: SMTP%"reith@3d.enet.dec.com"
|
| 560.740 | Galileo Mission Director Status Report - 01/29/93 | PONIL::J_BUTLER | E pur, si muove... | Mon Feb 01 1993 14:18 | 146 |
| Article 2967 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 01/29/93
Message-ID: <29JAN199319483136@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
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Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
January 22 - 28, 1993
SPACECRAFT
1. On January 22, real-time commands were sent to turn the Ultraviolet
Spectrometer (UVS) on for approximately one hour to exercise its grating
drive mechanism. Additionally, the Plasma Wave (PWS) instrument was turned
on from the stored sequence and remains on.
2. On January 22, real-time commands were sent to modify the System Fault
Protection (SFP) for science instruments. Specifically, the Energetic
Particle Detector (EPD) science alarm monitor was modified to turn the EPD
replacement heater on instead of the EPD supplemental heater. Also, the
SFP was modified to turn the Plasma Wave (PWS) and Heavy Ion Counter (HIC) on.
These changes were primarily necessitated by the changing thermal environment
as the spacecraft exceeds 1.2 solar AU.
3. On January 22, cruise science Memory Readouts (MROs) were performed for
the Extreme Ultraviolet Spectrometer (EUV), Magnetometer (MAG) and Dust
Detector (DDS) instruments. Preliminary analysis indicates the data was
received properly.
4. On January 22, an Ultra Stable Oscillator (USO) test was performed to
verify the health status of the USO and collect gravitational red shift
experiment data; long term trend analysis is continuing.
5. On January 25, the AACS (Attitude and Articulation Control Subsystem)
12.0 inflight load activities commenced. Real-time commands were first sent
to turn ranging off and the Two-Way Noncoherent (TWNC) on in order to maximize
the telecommunications performance. Then, the spacecraft was configured to a
quiescent state in preparation for the inflight load which included disabling
AACS system fault protection and setting the command loss timer to 18 hours.
Commands were then sent to load the "memory test" into the A memory which was
then used to validate the B memory. Upon successful validation of the
B memory, the original AACS 10.3 flight software was loaded into the B memory
and verified to be correct via Memory Readouts (MROs).
6. On January 26, approximately seven hours after the AACS B memory was
verified to be correct, commands were sent to swap to the B memory. Commands
were then sent to load the "memory test" into the B memory which was then
used to validate the A memory. Upon successful validation of the A memory,
the original AACS 10.3 flight software was loaded into the A memory and
verified to be correct via Memory Readouts (MROs).
Approximately seven hours later, real-time commands were sent to set the
command loss timer to 36 hours and to enable AACS system fault protection for
the intermediate wait period (approximately 23 hours) prior to loading the
new AACS flight software. Additionally, real-time commands were sent to turn
the Two-Way Noncoherent (TWNC) off for the purpose of collecting two-way
doppler data for navigation purposes. During the wait period, a NO-OP
command was sent to reset the command loss timer to 36 hours.
7. On January 27, after approximately a 23 hour wait period, real-time
commands were sent to set the command loss timer to 18 hours and to disable
the AACS system fault protection. The uplinking of the AACS 12.0 Flight
Software into memory A then began and continued for approximately 12 hours.
Memory Readouts (MROs) were performed to verify the uplink.
8. On January 28, after approximately 6 hours from the time of the AACS
12.0 Flight Software MROs of memory A, commands were sent to swap to the A
memory. Immediately after the swap, a Scan Actuator Subassembly (SAS) anomaly
occurred indicating that SAS slew rate errors occurred. The uplinking of the
AACS 12.0 flight software into memory B was temporarily suspended pending
anomaly resolution. Commands were then sent to reset the command loss timer
to 18 hours at 1530 UTC and 2245 UTC. Anomaly resolution is continuing at
the time of this writing.
9. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18DN
(4.1 volts). The DC measurement reads 142DN (16.7 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
10. The Spacecraft status as of January 28, 1993, is as follows:
a) System Power Margin - 74 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89 rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 7 degrees
off-sun (lagging) and 36 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 18 hours
Time To Initiation - 17 hours
TRAJECTORY
As of noon Thursday, January 28, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 36,574,100 km (0.24 AU)
Distance from Sun 176,192,200 km (1.18 AU)
Heliocentric Speed 125,900 km per hour
Distance from Jupiter 711,152,400 km
Round Trip Light Time 4 minutes, 6 seconds
SPECIAL TOPIC
1. As of January 28, 1993, a total of 64758 real-time commands have been
transmitted to Galileo since Launch. Of these, 59699 were initiated in the
sequence design process and 5059 initiated in the real-time command process.
In the past week, 376 real time commands were transmitted: 370 were initiated
in the sequence design process and six initiated in the real time command
process. Major command activities included commands to turn the UVS on/off,
turn the PWS on, modify SFP, turn ranging off, turn TWNC on, disable AACS SFP,
reset the command loss timer, enable the AACS SFP, turn the TWNC off, and
upload the AACS 12.0 flight software.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
|
| 560.741 | Galileo Update -- 01/29/93 | PONIL::J_BUTLER | E pur, si muove... | Mon Feb 01 1993 14:20 | 51 |
| Article 2968 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update #2 - 01/29/93
Message-ID: <29JAN199319501830@kelvin.jpl.nasa.gov>
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
January 29, 1993
The Galileo Spacecraft is operating normally in the all-spin mode at
2.9 rpm, and is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, after swapping to memory A with the AACS (Attitude and
Articulation Control Subsystem) 12.0 flight software, an anomaly occurred in
which the scan platform was unexpectedly slewed. Loading of memory B with
AACS 12.0 flight software has been temporarily suspended pending an
investigation of this anomaly. Tracking was scheduled over DSS-14 (Goldstone
70 meter antenna), DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid
70 meter antenna).
Today, January 29, 1993, loading of memory B with the AACS 12.0 flight
software was resumed. The problem associated with the unexpected slewing of
the scan platform has been resolved, and will recquire a patch to the AACS
12.0 flight software after the loading the the B memory has been completed.
Tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, the reconfiguration of the spacecraft following the completion
of the AACS 12.0 in-flight mode is scheduled. Tracking is scheduled over
DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while,
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/ |_|/ |_____|/ |
|
| 560.742 | Galileo Update -- 02/01/93 | PONIL::J_BUTLER | E pur, si muove... | Mon Feb 01 1993 19:04 | 45 |
| Article 2983 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/01/93
Message-ID: <1FEB199319402068@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 1, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 1200 bps (bits/second).
Over the weekend, the reconfiguration of the spacecraft following the
completion of the AACS (Attitude and Articulation Control Subsyste) 12.0
in-flight mode was completed on Saturday. Tracking is scheduled over
DSS-14 (Goldstone 70 meter antenna), DSS-43 (Canberra 70 meter antenna)
and DSS-63 (Madrid 70 meter antenna).
Today, February 1, 1993, no spacecraft activity is scheduled. Tracking
is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled over
DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never yell "Movie!" in a
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | crowded fire station.
|_____|/ |_|/ |_____|/ |
|
| 560.743 | Galileo Update -- 02/04/93 | PONIL::J_BUTLER | E pur, si muove... | Mon Feb 08 1993 18:38 | 122 |
| Article 3016 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/04/93
Message-ID: <8FEB199307465009@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
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Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
January 29 - February 4, 1993
SPACECRAFT
1. On January 29, the scan platform slew anomaly had been thoroughly
investigated and clearly understood. The anomaly was caused by a software
design problem present since before launch involving the improper setting of a
crucial variable needed to control the position of the scan platform. The
unintended scan platform slewing will only occur following the loading of new
flight software or in situations (Heartbeat Loss) in which the memories are
swapped and the off-line memory value of this variable is not consistent with
the then current position of the scan platform.
With the scan platform slew anomaly fully understood, the flight
software load process resumed with the uplinking of the AACS (Attitude and
Articulation Control Subsystem) 12.0 Flight Software into Memory B. Memory
Readouts (MROs) were then performed to verify the uplink.
2. On January 30, following the loading of the AACS 12.0 Flight Software
into Memory B, real-time commands were sent to patch the software to assure
that this crucial variable is set to a proper value (153 degrees). The
scan platform will remain at the 153 degree safe position until a permanent
software change is implemented, tested, and uplinked.
Additionally, real-time commands were sent to enable AACS system fault
protection, set the command loss timer to 10 days, configure the spacecraft for
the start of the EE-12B (Earth-Earth 12B) sequence memory load, and to update
several parameters for the AACS 12.0 Flight Software.
3. On February 1, a NO-OP command was sent to reset the command loss timer
to 10 days, its planned value during this mission phase.
4. On February 4, real-time commands were sent to turn the gyros on for
approximately two hours in order to collect gyro drift data. Data analysis
is in progress.
5. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18DN
(4.1 volts). The DC measurement reads 148DN (17.4 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
6. The Spacecraft status as of February 4, 1993, is as follows:
a) System Power Margin - 67 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 11 degrees
off-sun (lagging) and 34 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 237 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EE-12B prime sequence memory load was approved for transmission by
the Project on February 4, 1993. This sequence covers spacecraft activities
from February 8, 1993 to April 12, 1993. Scan platform activities were
removed from the EE-12B sequence due to the scan platform slew anomaly on
January 28 and renamed EG-12B prime.
TRAJECTORY
As of noon Thursday, February 4, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 41,961,000 km (0.28 AU)
Distance from Sun 184,221,200 km (1.23 AU)
Heliocentric Speed 122,500 km per hour
Distance from Jupiter 692,159,700 km
Round Trip Light Time 4 minutes, 42 seconds
SPECIAL TOPIC
1. As of February 4, 1993, a total of 64977 real-time commands have been
transmitted to Galileo since Launch. Of these, 59902 were initiated in the
sequence design process and 5075 initiated in the real-time command process.
In the past week, 219 real time commands were transmitted: 203 were initiated
in the sequence design process and 16 initiated in the real time command
process. Major command activities included commands to upload the AACS 12.0
Flight Software, patch the AACS 12.0 Flight Software, enable the AACS SFP,
reset the command loss timer, configure the spacecraft for the EE-12B
sequence, update AACS parameters, and turn the gyros on/off.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never yell "Movie!" in a
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | crowded fire station.
|_____|/ |_|/ |_____|/ |
|
| 560.744 | Galileo Update -- 02/08/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Feb 09 1993 12:25 | 44 |
| Article 3022 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/08/93
Message-ID: <9FEB199300481516@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 8, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 1200 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna) on Saturday.
Today, February 8, 1993, a routine RPM (Retro-Propulsion Module) 10-Newton
thruster flushing maintenance activity, SITURN, USO (Ultra-Stable Oscillator)
tests, and cruise science MROs (Memory Readouts) are scheduled. Real-time
commands to modify system fault protection parameters are also scheduled.
Tracking is scheduled over DSS-43 and DSS-63 (Madrid 70 meter antenna).
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never yell "Movie!" in a
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | crowded fire station.
|_____|/ |_|/ |_____|/ |
|
| 560.745 | Galileo Update -- 02/09/93 | PONIL::J_BUTLER | E pur, si muove... | Wed Feb 10 1993 13:24 | 48 |
| Article 3033 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/09/93
Message-ID: <10FEB199300122691@kelvin.jpl.nasa.gov>
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 9, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, a routine RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity, SITURN, USO (Ultra-Stable Oscillator) tests,
and cruise science MROs (Memory Readouts) were performed, as planned.
Real-time commands to modify system fault protection parameters were also
sent. Tracking was scheduled over DSS-43 (Canberra 70 meter antenna) and
DSS-63 (Madrid 70 meter antenna).
Today, February 9, 1993, no spacecraft activity or tracking is scheduled.
Tomorrow, real-time commands are scheduled to turn the UVS (Ultraviolet
Spectrometer) on and modify the system fault protection. Tracking is scheduled
over DSS-43 and DSS-63.
[NOTE: Today is the 3rd anniversary of Galileo's flyby of Venus. Ron Baalke].
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never yell "Movie!" in a
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | crowded fire station.
|_____|/ |_|/ |_____|/ |
|
| 560.746 | Galileo Update -- 02/11/93 | PONIL::J_BUTLER | E pur, si muove... | Mon Feb 15 1993 19:03 | 137 |
| Article 3059 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/11/93
Message-ID: <12FEB199304062790@kelvin.jpl.nasa.gov>
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Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
February 5 - 11, 1993
SPACECRAFT
1. On February 5, the EE-12B (Earth-Earth) prime sequence memory load was
uplinked to the spacecraft without incident. This sequence covers spacecraft
activities from February 8, 1993 to April 12, 1993.
2. On February 8, real-time commands were sent to modify the system fault
protection such that if spacecraft safing executes, the Plasma Wave Subsystem
(PWS) supplemental heater will be turned on. This change was necessitated by
the increasing solar AU distances.
3. On February 8, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
maintenance activity was performed; all 12 thrusters were "flushed" during the
activity. Spacecraft activity throughout the period was normal.
4. On February 8, the spacecraft performed a 31.5 degree SITURN for the
purpose of attitude maintenance. The Z thrusters were used during the
activity. After the SITURN completed, the Near Infrared Mapping Spectrometer
(NIMS) shield temperature increased to 51.8 degrees C which was 1.8 degrees C
above the 3-210 non-operating limit. A waiver was generated and approved by
the Project for a non-operating temperature limit to 55 degrees C.
5. On February 8, an Ultra-Stable Oscillator (USO) test was performed to
verify the health status of the USO and to collect gravitational red shift
experiment data; long term trend analysis is continuing.
6. On February 8, cruise science Memory Readouts (MROs) were performed for
the Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and
Magnetometer (MAG) instruments. Preliminary analysis indicates the data
was received properly.
7. During the period from February 10 through February 11, a navigation cycle
was performed. This navigation cycle provided near-continuous acquisition of
two-way doppler and ranging data during four consecutive passes of the
spacecraft over DSS-43 (Canberra 70 meter antenna), DSS-63 (Madrid 70 meter
antenna), DSS-14 (Goldstone 70 meter antenna), and then back to DSS-43.
8. On February 10, real-time commands were sent to turn the Ultraviolet
Spectrometer (UVS) on to exercise its grating drive mechanism and the
instrument remains on. The UVS high voltage was also commanded off to
properly configure the instrument for the Earth-Jupiter cruise phase.
9. On February 10, real-time commands were sent to modify the System Fault
Protection (SFP). Specifically, the Relay/JOI (Jupiter Orbit Insertion)
System Fault Protection (SFP) was patched for use during non-critical spin-up
activities. During commanding, radiation terminated due to bit verify errors.
Remaining command radiation was resumed without incident. Analysis of this
anomaly is in progress.
10. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19DN
(4.3 volts). The DC measurement reads 146DN (17.2 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
11. The Spacecraft status as of February 11, 1993, is as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 16 degrees
off-sun (leading) and 7 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 212 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The LGA-2 (Low Gain Antenna #2) Swing Test sequence memory load was
approved for generation by the Project on February 8, 1993. This sequence
includes Low Gain Antenna (LGA)-2 deploy/retract activities on
February 17, 1993, and wobble identification activities on February 25-26,
1993.
TRAJECTORY
As of noon Thursday, February 11, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 48,015,000 km (0.32 AU)
Distance from Sun 192,745,800 km (1.29 AU)
Heliocentric Speed 119,100 km per hour
Distance from Jupiter 673,957,200 km
Round Trip Light Time 5 minutes, 22 seconds
SPECIAL TOPIC
1. As of February 11, 1993, a total of 65027 real-time commands have been
transmitted to Galileo since Launch. Of these, 59952 were initiated in the
sequence design process and 5075 initiated in the real-time command process.
In the past week, 50 real time commands were transmitted: 50 were initiated in
the sequence design process and none initiated in the real time command
process. Major command activities included commands to uplink the EE-12B
prime sequence memory load, modify system fault protection, turn the UVS
instrument on, and turn the UVS high voltage off.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never yell "Movie!" in a
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | crowded fire station.
|_____|/ |_|/ |_____|/ |
|
| 560.747 | | SKYLAB::FISHER | I *hate* questionnaires--Worf | Tue Feb 16 1993 15:41 | 7 |
| Anyone know anything about the LGA? I sort of thought it was an omni antenna,
and not retract/deployable. The "LGA Swing Test" in .746 kind of shows that idea
to be bogus. (Do they REALLY want to retract the LGA????)
It also sounds like there may be more than 1 LGA?
Burns
|
| 560.748 | | PRAGMA::GRIFFIN | Dave Griffin | Tue Feb 16 1993 16:36 | 16 |
| Galileo has 4 antennas (not counting radio-science stuff, which are, technically,
antennas).
o HGA - Big sucker that isn't working.
o LGA - Smaller, directional antenna that is at the end of the HGA
center section boom.
o LGA - Even smaller, probably omni, antenna attached to one of the RTG booms.
This looks more like a whip antenna than dish.
o Probe/Relay - "Small" antenna (smaller than the first LGA) that presumably
only chats with the atmospheric probe.
When I was at JPL a few months ago I took a few pictures of the full-size
model they have in the lobby. I'll see if I can spot any obvious mechanisms
in the larger LGA.
- dave
|
| 560.749 | | HELIX::MAIEWSKI | | Tue Feb 16 1993 18:37 | 4 |
| Just curious, on the full scale model at JPL is the HGA open, closed, or
partly open with 3 stuck ribs?
George
|
| 560.750 | | PRAGMA::GRIFFIN | Dave Griffin | Tue Feb 16 1993 18:50 | 5 |
| Heh, heh...
Open.
- dave
|
| 560.751 | | FASDER::ASCOLARO | Anthony Edward, 5/5/92 | Wed Feb 17 1993 17:02 | 6 |
| Isn't this LGA thingie the 'last ditch effort' to open the HGA?
I thought they had talked about some kind of swinging stuff to open it,
no?
Tony
|
| 560.752 | | PRAGMA::GRIFFIN | Dave Griffin | Wed Feb 17 1993 17:17 | 8 |
| Re: .748
Nothing in the photos I have as far as mechanisms. The LGA was in the
shadows and somewhat far away (Galileo is BIG!). Most areas have (thermal?)
blankets around them as well, which tend to hide mechanical gizmos.
- dave
|
| 560.753 | Galileo Update -- 02/17/93 | PONIL::J_BUTLER | E pur, si muove... | Mon Feb 22 1993 18:33 | 46 |
| Article 3096 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/17/93
Message-ID: <18FEB199301245217@kelvin.jpl.nasa.gov>
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 17, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, transmission of the LGA-2 (Low Gain Antenna #2) swing
mini-sequence was uplinked. No other spacecraft activity was scheduled.
Tracking was scheduled over DSS-43 (Canberra 70 meter antenna) and
DSS-14 (Goldstone 70 meter antenna).
Today, February 17, 1993, LGA-2 deployment/retraction was accomplished
as planned. Tracking is scheduled over DSS-14, DSS-43 and DSS-63 (Madrid
70 meter antenna).
Tomorrow, the AACS (Attitude and Articulation Control Subsystem) flight
software patch is scheduled to be uplinked. Tracking is scheduled
over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If you don't stand for
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/ |_|/ |_____|/ | for anything.
|
| 560.754 | Galileo Update -- 02/18/93 | PONIL::J_BUTLER | E pur, si muove... | Mon Feb 22 1993 18:36 | 116 |
| Article 3109 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/18/93
Message-ID: <19FEB199316570228@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
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Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
February 12 - 18, 1993
SPACECRAFT
1. On February 15, a NO-OP command was sent to reset the command loss timer
to 240 hours, its planned value during this mission phase.
2. On February 16, the Low Gain Antenna (LGA-2) deploy/retract mini-sequence
was uplinked to the spacecraft without incident. This mini-sequence includes
LGA-2 deploy/retract activities on February 17, 1993 and wobble identification
activities on February 25-26, 1993. Additionally, Delayed Action Commands
(DACs) were sent to disable portions of the internal attitude control subsystem
fault protection prior to the deploy/retract activities and to re-enable FM 31
after the activities had completed.
3. On February 17, the LGA-2 was deployed/retracted three times beginning at
1633 UTC and completing at 1723 UTC. Real-time commands were then sent to
reacquire celestial reference at the completion of the star scanner checkout.
4. On February 18, a permanent software patch was uplinked to the spacecraft
to fix the AACS (Attitude and Articulation Control Subsystem) 12.0 flight
software design problem involving the improper setting of a crucial variable
needed to control the position of the scan platform. The patch was uplinked
nominally. This design problem was encountered during the AACS 12.0 inflight
load and reported initially in the Mission Director's Report
January 22-28, 1993.
5. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 20DN
(4.5 volts). The DC measurement reads 139DN (16.3 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
6. The Spacecraft status as of February 18, 1993, is as follows:
a) System Power Margin - 71 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 11 degrees
off-sun (leading) and 7 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 233 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The LGA-2 deploy/retract mini-sequence memory load was approved for
transmission by the Project on February 16, 1993. This sequence includes
Low Gain Antenna (LGA-2) deploy/retract activities on February 17, 1993, and
wobble identification activities on February 25-26, 1993.
2. The EJ-1 (Earth-Jupiter #1) Final Profile Design was approved by the
Project on February 17, 1993. This sequence covers spacecraft activities
from April 12, 1993 to June 14, 1993.
TRAJECTORY
As of noon Thursday, February 18, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 54,954,200 km (0.37 AU)
Distance from Sun 201,645,400 km (1.35 AU)
Heliocentric Speed 115,700 km per hour
Distance from Jupiter 656,560,300 km
Round Trip Light Time 6 minutes, 8 seconds
SPECIAL TOPIC
1. As of February 18, 1993, a total of 65048 real-time commands have been
transmitted to Galileo since Launch. Of these, 59958 were initiated in the
sequence design process and 5090 initiated in the real-time command process.
In the past week, 21 real time commands were transmitted: 6 were initiated in
the sequence design process and 15 initiated in the real time command process.
Major command activities included commands to reset the command loss timer,
uplink the LGA-2 deploy/retract mini-sequence load, disable/enable FM 31,
reacquire celestial reference, and uplink the AACS 12.0 flight software patch.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If you don't stand for
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/ |_|/ |_____|/ | for anything.
|
| 560.755 | CD-ROMs of GALILEO images | VERGA::KLAES | Life, the Universe, and Everything | Tue Feb 23 1993 18:40 | 50 |
| From: DECWRL::"baalke@kelvin.Jpl.Nasa.Gov" "Ron Baalke" 21-FEB-1993
19:34:34.95
To: sci-space-news@ames.arc.nasa.gov
CC:
Subj: Galileo CD-ROMs
=====================
GALILEO CD-ROMs
February 21, 1993
=====================
Five Galileo CD-ROMs (volumes 2 through 6) have been released by the
Galileo project. These CD-ROMs contains the raw images taken by the Galileo
spacecraft on its Venus flyby in February 1990 and its first flyby of
the Earth and Moon in December 1990.
The CD-ROMs can be obtained from the National Space Science Data Center
(NSSDC) at the Goddard Space Flight Center. The charge for the CD-ROMs is $20
for the first CD-ROM, and $6 for any additional CD-ROM in an order. The
charges can be waived in certain hardship cases, contact NSSDC for
more details on this.
NSSDC's address is:
National Space Science Data Center
Goddard Space Flight Center
Greenbelt, Maryland 20771
Phone: (301) 286-6695
Email address: request@nssdca.gsfc.nasa.gov
You can also reach NSSDC by logging on to their computer. To log
onto the NSSDC computer, telnet to NSSDC.GSFC.NASA.GOV and give the
username "NSSDC". You will then be connected to a menu system which
allows you to use the "Master Directory". You can also leave
questions and orders for the NSSDC staff. If this is the first time
you have used the NSSDC "NODIS" system, it will ask you for
information (name, address, ...) to keep a database of NSSDC users.
Software the display the images on an IBM PC or Macintosh is available
from NSSDC ($9 shipping and handling charge). The software is also available
using anonymous ftp to ames.arc.nasa.gov in the pub/SPACE/SOFTWARE directory.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If you don't stand for
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/ |_|/ |_____|/ | for anything.
|
| 560.756 | Galileo Update -- 02/24/93 | CXDOCS::J_BUTLER | E pur, si muove... | Thu Feb 25 1993 14:32 | 43 |
| Article 3131 of sci.space.news:
Newsgroups: sci.space.news
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/24/93
Message-ID: <24FEB199319000180@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 24, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, February 24, 1993, real-time commands are scheduled to perform a
scan actuator subassembly friction test. Tracking is scheduled over DSS-14,
DSS-42 (Canberra 34 meter antenna) and DSS-63.
Tomorrow, a wobble identification is scheduled. Tracking is scheduled
over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If you don't stand for
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/ |_|/ |_____|/ | for anything.
|
| 560.757 | GALILEO Earth-Moon Animation | VERGA::KLAES | Life, the Universe, and Everything | Sun Feb 28 1993 20:15 | 62 |
| From: DECWRL::"baalke@kelvin.Jpl.Nasa.Gov" "Ron Baalke" 28-FEB-1993
To: sci-space-news@ames.arc.nasa.gov
CC:
Subj: Galileo Earth-Moon Animation
==============================
GALILEO EARTH-MOON ANIMATION
February 27, 1993
==============================
The Galileo Earth-Moon Conjunction animation is now available at the Ames
Space Archives. This animation is courtesy of Paul Geissler and Larry Kendall
from the University of Arizona, with permission from Mike Belton, Galileo
Imaging Team Leader. The animation was formed from 46 images taken by Galileo
spaecraft shortly after its Earth flyby on December 16, 1992, and is in a
compressed PICT format to be used with the NIH Image software on the Macintosh.
Efforts to convert the animation to other formats is currently in progress.
The animation is available using anonymous ftp to:
ftp: ames.arc.nasa.gov (128.102.18.3)
user: anonymous
cd: pub/SPACE/ANIMATION
files:
Earth_Moon_Movie.Hqx
Earth_Moon_Movie.txt
--------------------------------------------------------------------------
Earth_Moon_Movie.txt
Earth_Moon_Movie.Hqx is in BinHex format for the Macintosh. The
unHexed file can be opened as a stack and animated by NIH Image,
a public domain package available from Wayne Rasband at the
National Institutes of Health. When uncompressed, the movie takes
up about 6 Mb of memory.
This is a time-lapse sequence taken by the Galileo spacecraft on
December 16, 1992, eight days after its flyby of the Earth/Moon system
en route to Jupiter. The 46 frames span 15 hours of motion by the Earth,
Moon and spacecraft. These images were acquired with the 0.968 micron
filter so that both vegetated and unvegetated land masses appear bright
in contrast to the oceans. South is at top. Visible are the Pacific basin,
Australia, Southeast Asia, India, and finally Arabia and the horn of Africa.
A remarkable feature of this time-lapse sequence is the specular reflection
or sun glint from the sea surface. Depending on the roughness of the water
the extent of specular reflection varies rapidly, expanding over rough
waters and contracting to a point over still oceanic pools such as near
the west coast of Australia.
Source: Paul Geissler and Larry Kendall, University of Arizona, with
permission of M.J.S. Belton
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If you don't stand for
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/ |_|/ |_____|/ | for anything.
% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
% Subject: Galileo Earth-Moon Animation
|
| 560.758 | Galileo Update -- 02/24/93 | PONIL::J_BUTLER | E pur, si muove... | Mon Mar 01 1993 13:14 | 87 |
| Article 3131 of sci.space.news:
Newsgroups: sci.space.news
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/24/93
Message-ID: <24FEB199319000180@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 24, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, February 24, 1993, real-time commands are scheduled to perform a
scan actuator subassembly friction test. Tracking is scheduled over DSS-14,
DSS-42 (Canberra 34 meter antenna) and DSS-63.
Tomorrow, a wobble identification is scheduled. Tracking is scheduled
over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If you don't stand for
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/ |_|/ |_____|/ | for anything.
Article 3131 of sci.space.news:
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/24/93
Message-ID: <24FEB199319000180@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
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Lines: 24
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
February 24, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, February 24, 1993, real-time commands are scheduled to perform a
scan actuator subassembly friction test. Tracking is scheduled over DSS-14,
DSS-42 (Canberra 34 meter antenna) and DSS-63.
Tomorrow, a wobble identification is scheduled. Tracking is scheduled
over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If you don't stand for
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/ |_|/ |_____|/ | for anything.
|
| 560.759 | Galileo Status Report -- 19-25 Feb 1993 | PONIL::J_BUTLER | E pur, si muove... | Mon Mar 01 1993 13:58 | 134 |
| Article 3135 of sci.space.news:
Newsgroups: sci.space.news
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 02/25/93
Message-ID: <25FEB199323335230@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
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Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
February 19 - 25, 1993
SPACECRAFT
1. On February 22, a NO-OP command was sent to reset the command loss timer
to 240 hours, its planned value during this mission phase.
2. During the period from February 23 through February 24, a navigation cycle
was performed. This navigation cycle provided near-continuous acquisition of
two-way doppler and ranging data during four consecutive passes of the
spacecraft over DSS-63 (Madrid 70 meter antenna), DSS-14 (Goldstone 70 meter
antenna), DSS-42 (Canberra 34 meter antenna), and then back to DSS-63.
3. On February 24, real-time commands were sent to perform a Scan Actuator
Subassembly (SAS) friction calibration to verify that the friction level has
not changed; analysis of the data is in progress.
4. On February 25, a wobble angle identification (ID) activity was performed
in the all-spin mode with the scan platform cone angle at 0 degrees and in the
dual-spin mode with the scan platform cone angle at 153 degrees; analysis of
the data is in progress.
5. On February 25, Delayed Action Commands (DACs) were sent to turn the
Photometric Calibration Target (PCT) No. 1 heater on March 2 in accordance
with the Retro-Propulsion Module (RPM) pressure profile strategy.
6. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19DN
(4.3 volts). The DC measurement reads 141DN (16.6 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
7. The Spacecraft status as of pin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 7 degrees
off-sun (leading) and 7 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 236 hours
GDS (Ground Data Systems):
1. A review of the Phase 1 Telemetry Software Requirements Document (SRD)
was completed on February 24th. No significant problems were identified.
A final version incorporating comments received at the meeting will be
published next week. Phase 1 capabilities support the new mission baseline
through successful return of the Probe data and loading of the Phase 2 Flight
Software for orbital operations in April 96.
2. Galileo participated in the DSN (Deep Space Network) Version 1.5 GCF
(Ground Communications Facility) upgrade data flow test on February 24, 1993
from 19:00 to 01:00 GMT using DSS-10. The purpose of this test was to
demonstrate telemetry data flow path through the DSN SFOC Gateway (SG) to the
Error Correction and Switching (ECS) subsystem; the current data flow is the
External User Gateway (EUG) to the ECS. This test exercised telemetry data
for Galileo only. The test failed due to blocks of data being dropped between
the SG and the ECS. The cause of this problem is unknown and is under
investigation. A test report is expected from the DSN GCF cognizant engineer
during the week of March 1. A retest of telemetry flow plus testing of
command, monitor and tracking data flow through the SG to ECS interface will
be performed prior to March 15, 1993. The Version 1.5 GCF upgrade is
scheduled to be operational on March 15, 1993.
3. The IBM 3090/200 to IBM ES/9000 transition certification testing
activities began on February 22. Initial testing by the Data Management Team
(DMT) has uncovered job control default parameter differences between the two
machines which require modifications to runstreams used by the DMT. Flight S/W
certification testing is expected to begin during the week of March 1. Galileo
certification testing activities will continue thru March/April 1993.
Following successful completion of certification testing Galileo will
transition from the current IBM 3090/200 to the new IBM ES/9000-6121/610.
TRAJECTORY
As of noon Thursday, February 25, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 62,966,500 km (0.42 AU)
Distance from Sun 210,819,800 km (1.41 AU)
Heliocentric Speed 112,400 km per hour
Distance from Jupiter 639,964,600 km
Round Trip Light Time 07 min. 02 sec.
SPECIAL TOPIC
1. As of February 25, 1993, a total of 65066 real-time commands have been
transmitted to Galileo since Launch. Of these, 59961 were initiated in the
sequence design process and 5105 initiated in the real-time command process.
In the past week, 18 real time commands were transmitted: 3 were initiated in
the sequence design process and 15 initiated in the real time command process.
Major command activities included commands to reset the command loss timer,
perform a Scan Actuator Subassembly (SAS) friction test, and a DAC to turn on
the PCT No. 1 heater.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If you don't stand for
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/ |_|/ |_____|/ | for anything.
|
| 560.760 | Galileo Update -- 03/01/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Mar 02 1993 13:07 | 45 |
| Article 3172 of sci.space.news:
Newsgroups: sci.space.news
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/01/93
Message-ID: <1MAR199323053180@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
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Lines: 26
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 1, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 1200 bps (bits/second).
Over the weekend, no spacecraft activity or tracking was scheduled.
Today, March 1, 1993, a routine RPM (Retro-Propulsion Module) 10-Newton
thruster flushing maintanence activity, SITURN, USO (Ultra Stable Oscillator)
test and cruise science memory readouts are scheduled. Additionally, the AACS
(Attitude and Articulation Control Subsystem) cone controller update
mini-sequence is scheduled to be uplinked. Tracking is scheduled over DSS-63
(Madrid 70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Tomorrow, the downlink telemetry rate is scheduled to change to 40 bps
uncoded. Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | If you don't stand for
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | something, you'll fall
|_____|/ |_|/ |_____|/ | for anything.
|
| 560.761 | Galileo Update -- 03/02/93 | PONIL::J_BUTLER | E pur, si muove... | Wed Mar 03 1993 14:39 | 47 |
| Article 3179 of sci.space.news:
Newsgroups: sci.space.news
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/02/93
Message-ID: <2MAR199321582750@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 2, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Yesterday, a routine RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintanence activity, SITURN, USO (Ultra Stable Oscillator) test and
cruise science memory readouts were performed, as scheduled. Additionally,
the AACS (Attitude and Articulation Control Subsystem) cone controller update
mini-sequence was uplinked. Tracking was scheduled over DSS-63 (Madrid
70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, March 2, 1993, the downlink telemetry rate was changed to 40 bps
uncoded. Tracking was performed over DSS-14.
Tomorrow, the downlink telemetry rate is scheduled to change to 1200 bps
coded. Real-time commands are scheduled to update the AACS cone controller
and spin detector parameters. Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | It's kind of fun to do
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | the impossible.
|_____|/ |_|/ |_____|/ | Walt Disney
|
| 560.762 | Re: .757 | PRAGMA::GRIFFIN | Dave Griffin | Thu Mar 04 1993 17:10 | 8 |
| The earth_moon_movie is available from the archives at:
pragma::public:[nasa]
I'll put the PC version there asap after it is announced.
- dave
|
| 560.763 | Gaspra animation | VERGA::KLAES | Life, the Universe, and Everything | Sat Mar 06 1993 18:15 | 59 |
| Article: 32850
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro,alt.sci.planetary
Subject: Gaspra Animation
Date: 6 Mar 1993 05:44 UT
Organization: Jet Propulsion Laboratory
==============================
GASPRA ANIMATION
March 5, 1993
==============================
A Gaspra animation is now available at the Ames Space Archives.
This animation is courtesy of Jeff Alu. The animation was formed from
11 images taken by the Galileo spaecraft shortly before its closest
approach to the asteroid in October 1991. The animation is in FLI
format. Using anonymous ftp, the animation can be obtained from:
ftp: ames.arc.nasa.gov (128.102.18.3)
user: anonymous
cd: pub/SPACE/ANIMATION
files:
gaspra.fli
gaspra.txt (see below)
--------------------------------------------------------------------------
gaspra.txt
This animation consists of 11 images taken by the Galileo
spacecraft as it flew by the asteroid 951 Gaspra on October 29, 1991.
The animation shows Gaspra growing progressively larger in the field
of view of Galileo's solid-state imaging camera as the spacecraft
approached the asteroid. Sunlight is coming from the right. Gaspra is
roughly 17 kilometers (10 miles) long, 10 kilometers (6 miles) wide.
The first frame of the animation (smallest image) was taken 5 3/4
hours before closest approach when the spacecraft was 164,000
kilometers (102,000 miles) from Gaspra, the last frame (largest image)
at a range of 16,000 kilometers (10,000 miles), 30 minutes before
closest approach.
Gaspra spins once in roughly 7 hours, so these images capture
almost one full rotation of the asteroid. Gaspra spins
counterclockwise; its north pole is to the upper left, and the "nose"
which points upward in the first image, is seen rotating back into
shadow, emerging at lower left, and rotating to upper right. Several
craters are visible on the newly seen sides of Gaspra, but none
approaches the scale of the asteroid's radius. Evidently, Gaspra lacks
the large craters common on the surfaces of many planetary satellites,
consistent with Gaspra's comparatively recent origin from the
collisional breakup of a larger body.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | It's kind of fun to do
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | the impossible.
|_____|/ |_|/ |_____|/ | Walt Disney
|
| 560.764 | Galileo Update -- 03/05/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Mar 09 1993 13:38 | 157 |
| Article 3193 of sci.space.news:
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!parc!biosci!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 03/05/93
Keywords: Galileo, JPL
Message-ID: <6MAR199301094510@kelvin.jpl.nasa.gov>
Date: 6 Mar 93 01:09:00 GMT
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Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
February 25 - March 4, 1993
SPACECRAFT
1. On March 1, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
maintenance activity was performed; all 12 thrusters were flushed during the
activity. There was a small change in velocity caused by imbalances in the
firings of the S-thrusters. This effect was first noticed during the RPM
thruster flushing activity on February 8, 1993.
2. On March 1, a SITURN was scheduled in the EE-12B (Earth-Earth #12B) prime
sequence. The purpose of the SITURN was to ensure the spacecraft was at the
EE-12B prime attitude after the close of the spacecraft contingency window.
3. On March 1, the Attitude and Articulation Control Subsystem (AACS) cone
controller parameter update mini-sequence was uplinked to the spacecraft
without incident. This sequence which executed on March 3 verified the cone
controller performance with the current gains, updated the cone controller
gains, verified the cone controller performance with the updated gains, and
updated spin detector parameters.
4. On March 2, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect gravitational red shift experiment
data; long term trend analysis is continuing.
5. On March 2, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer
(MAG) instruments. Preliminary analysis indicates the data was received
properly.
6. On March 3, real-time commands were sent to update the attitude control
subsystem cone controller and spin detector parameters in support of the AACS
mini-sequence uplinked on Monday.
7. On March 4, real-time commands were sent to turn the Radioisotope
Thermoelectric Generator (RTG) boom heaters on and enable their temperature
control monitors in accordance with the Retro-Propulsion Module (RPM) pressure
profile strategy and to prepare for the 10.5 rpm spin up wobble compensation
scheduled for March 10.
8. On March 4, the Energetic Particle Detector (EPD) motor maintenance
exercise was performed which stepped the motor through its eight operating
positions and then returned to the normal position (No. 4). Later the EPD
shade was retracted nominally via the spacecraft stored sequence. Retraction
was confirmed via EPD detector temperature telemetry.
9. On March 4, a command threshold test was performed. Data analysis is in
progress at the writing of this report.
10. On March 4, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV). Analysis indicates the data was
received properly.
11. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19DN
(4.3 volts). The DC measurement reads 141DN (16.6 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
12. The Spacecraft status as of March 4, 1993, is as follows:
a) System Power Margin - 40 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.88 rpm/Star Scanner
d) Spacecraft Attitude is approximately 3 degrees
off-sun (leading) and 8 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna- 40bps(uncoded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 239 hours
GDS (Ground Data Systems):
1. Galileo participated in a re-test of the DSN (Deep Space Network)
Version 1.5 GCF (Ground Communications Facility) upgrade data flow test on
3 March. The purpose of this test was to demonstrate a new Galileo data flow
path through the DSN SFOC Gateway (SG) to the Error Correction and Switching
(ECS) subsystem. The 3 March test exercised telemetry, monitor and tracking
data for Galileo only. The test failed due to blocks of data being dropped
between the SG and the ECS for 134.4 KBPS. The cause of this problem is
unknown and is under investigation. Another retest will be performed prior
to March 15, 1993. In addition, Galileo participated in a CMD data flow test
on 2 March. The purpose of this test was to verify the CMD flow through the
SG and ECS interface. This test was canceled at the beginning of the test
period due to the unavailability of the necessary communication resources.
A retest of the CMD data flow will be rescheduled prior to 15 March. The
Version 1.5 GCF upgrade is scheduled to go into operations on 15 March.
2. A MOSO System Test for GLL MGDS V18 Command was performed 2 March from
20:00 to 00:00 GMT using MGDS SIM. The purpose of this test was to exercise
the connectivity of V18 CMD with a simulated DSN station (and CPA). This test
was unsuccessful due to a configuration (setup) problem between the MGDS CMD
and the Project Database (PDB). The configuration problems were resolved on
3 March. Another MOSO System Test of V18 CMD will be performed prior to
8 March. The System Test Review for V18 CMD is scheduled for 8 March.
TRAJECTORY
As of noon Thursday, March 4, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 72,166,500 km (0.48 AU)
Distance from Sun 220,187,100 km (1.47 AU)
Heliocentric Speed 109,300 km per hour
Distance from Jupiter 624,151,800 km
Round Trip Light Time 8 minutes, 4 seconds
SPECIAL TOPIC
1. As of March 4, 1993, a total of 65099 real-time commands have been
transmitted to Galileo since Launch. Of these, 59993 were initiated in the
sequence design process and 5106 initiated in the real-time command process.
In the past week, 33 real time commands were transmitted: 32 were initiated
in the sequence design process and 1 initiated in the real time command
process. Major command activities included commands to uplink the AACS cone
controller parameter update mini-sequence, update the cone controller and
spin detector parameters, reactivate the HGA unlatch function, and turn the
RTG boom heaters on and enable their temperature control monitors.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | It's kind of fun to do
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | the impossible.
|_____|/ |_|/ |_____|/ | Walt Disney
|
| 560.765 | Galileo Update -- 03/08/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Mar 09 1993 13:39 | 48 |
| Article 3208 of sci.space.news:
Newsgroups: sci.space.news
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From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/08/93
Message-ID: <8MAR199319293350@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
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Date: Mon, 8 Mar 1993 19:29:00 GMT
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Lines: 29
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 8, 1993
The Galileo Spacecraft is operating normally in the all-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Over the weekend, telecommunications tests and cruise science memory
readouts were scheduled on Sunday. Tracking was scheduled over DSS-63
(Madrid 70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, March 8, 1993, the TCM-19 (Trajectory Correction Maneuver #19)
memory load is scheduled to be uplinked. Real-time commands are also
scheduled to update acquisition sensors parameters. Cruise science memory
readouts are also scheduled. Tracking is scheduled over DSS-14, DSS-42
(Canberra 34 meter antenna) and DSS-63.
Tomorrow, the TCM-19 is scheduled to execute. Also, the 10 rpm spinup
mini-sequence is scheduled to be uplinked, along with real-time commands to
update attitude control subsystem parameters for the spinup.
Tracking is scheduled over DSS-14, DSS-42 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | It's kind of fun to do
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | the impossible.
|_____|/ |_|/ |_____|/ | Walt Disney
|
| 560.766 | Galileo Update - 03/09/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Mar 16 1993 15:02 | 47 |
| Article 3212 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!elroy.jpl.nasa.gov!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/09/93
Message-ID: <9MAR199318343550@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
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Date: Tue, 9 Mar 1993 18:34:00 GMT
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Lines: 28
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 9, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Yesterday, the TCM-19 (Trajectory Correction Maneuver #19) memory load
was uplinked, as planned. Real-time commands were also sent to update
acquisition sensors parameters. Cruise science memory readouts were also
scheduled. Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna),
DSS-42 (Canberra 34 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, March 9, 1993, the TCM-19 is scheduled to execute. Also, the
10 rpm spinup mini-sequence is scheduled to be uplinked, along with real-time
commands to update attitude control subsystem parameters for the spinup.
Tracking is scheduled over DSS-14, DSS-42 and DSS-63.
Tomorrow, under stored sequence control, the spacecraft will spinup to
10.5 rpm. Tracking is scheduled over DSS-14, DSS-42 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | It's kind of fun to do
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | the impossible.
|_____|/ |_|/ |_____|/ | Walt Disney
|
| 560.767 | Galileo Updates 1 & 2 - 03/10/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Mar 16 1993 15:04 | 76 |
| Article 3216 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/10/93
Message-ID: <10MAR199323562373@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
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Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 10, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Yesterday, the TCM-19 (Trajectory Correction Maneuver #19) executed,
as planned. Also, the 10 rpm spinup mini-sequence was uplinked, following
real-time commands to update attitude control subsystem parameters for the
spinup. Tracking was scheduled over DSS-14 (Goldstone 70 meter antenna),
DSS-42 (Canberra 34 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, March 10, 1993, the spacecraft, under stored sequence control,
is scheduled to spinup to 10.5 rpm. Tracking is scheduled over DSS-14,
DSS-42 and DSS-63.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-14, DSS-42 and DSS-63.
{Footer and next header deleted - JEB}
GALILEO MISSION STATUS
March 10, 1993
The Galileo spacecraft is 81 million kilometers (51 million
miles) from Earth, travelling in its orbit at 29.6 kilometers per
second or about 66,000 miles per hour. It is headed out away
from the Sun (at almost a million miles per day), toward its
flyby of the asteroid Ida on August 28, 1993 and its arrival in
Jupiter orbit on December 7, 1995.
The spacecraft health and performance continue to be
excellent, except that the high-gain antenna is still only partly
deployed. It is transmitting telemetry at 1200 bits per second
over its low-gain antenna.
Galileo's spin rate was increased to 10.5 rpm today to
demonstrate the high spin rate required for probe release (July
1995) and subsequent activities using the large, 400-newton
rocket engine. The spin rate will be returned to 3.15 rpm on
Friday.
Yesterday Galileo carried out a trajectory-correction
maneuver (about 2.1 meters per second or 4.7 mph) to target it
for the Ida encounter.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | It's kind of fun to do
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | the impossible.
|_____|/ |_|/ |_____|/ | Walt Disney
|
| 560.768 | Galileo Update -- 03/11/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Mar 16 1993 15:16 | 199 |
| Article 3241 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/11/93
Message-ID: <12MAR199301145780@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
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Date: Fri, 12 Mar 1993 01:14:00 GMT
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Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
March 5 - 11, 1993
SPACECRAFT
1. On March 5, a Radio Frequency Subsystem Tracking Loop Capacitor (RFSTLC)
test was performed over DSS-63 (Madrid 70 meter antenna). Preliminary
analysis indicates the capacitors continue to operate normally.
2. On March 7, cruise science Memory Readouts (MROs) were performed for the
Magnetometer (MAG) instrument. Preliminary analysis indicates the data was
received properly.
3. On March 7, a Command Detector Unit Signal-to-Noise Ratio (CDUSNR) test
was performed using LGA-1 (Low Gain Antenna #1) over DSS-63. Detailed
analysis of the data is in progress.
4. On March 8, a Radio Frequency Subsystem Automatic Gain Control (RFSAGC)
test was performed using LGA-1 over DSS-43 (Canberra 70 meter antenna).
Quick look analysis indicates the test went well. Detailed analysis is in
progress.
5. On March 8, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV). The MROs were received without
incident.
6. On March 8, the Trajectory Correction Maneuver (TCM-19) sequence memory
load was uplinked to the spacecraft without incident. The Energetic Particle
Detector (EPD) instrument was stepped to Sector 0 which is the predicted least
contaminated position in preparation for the execution of TCM-19 and returned
to Sector 4 after completion of the maneuver.
7. On March 8, real-time commands were sent to update the Acquisition Sensor
(AS) parameter for a solar distance of 1.5 AU. The AS parameter is updated
periodically due to the changing spacecraft to sun distance.
8. On March 9, TCM-19 was performed on the spacecraft. The maneuver
consisted of two axial segments imparting a total delta velocity of 2.12 m/sec.
This maneuver was executed at 1200 bps with the spacecraft pointed
approximately three degrees off the sun.
All RPM (Retro-Propulsion Module) pressures and temperatures and attitude
control indicators were near predicted levels. After the axial burn segments,
the sequence planned spin correction executed but the pointing correction was
not needed. Preliminary radio navigation data indicates a 0.25 percent
overburn.
9. On March 10, Delayed Action Commands (DACs) were sent to perform a wobble
compensation prior to the scheduled spacecraft spinup to 10.5 RPM. The DACs
to slew the Radioisotope Thermoelectric Generator (RTG) booms executed prior
to turning the RTG boom heaters off.
10. On March 10, real-time commands were sent to turn the RTG boom heaters off
and to update the attitude control subsystem parameters required to spin the
spacecraft up to 10.5 RPM.
11. On March 10, the 10 RPM spinup mini-sequence was uplinked to the
spacecraft without incident. The spacecraft under stored sequence control
initiated the spinup at approximately 2047 UTC and completed at 2118 UTC for a
duration of 31 minutes. After the spinup completed, real-time commands were
sent to lower the star scanner threshold in order to obtain star data for
attitude and wobble determination.
12. On March 10, while the spacecraft was at high spin (10.5 rpm), real-time
commands were sent to warmup the High Gain Antenna (HGA) motors and to hammer
the motors for 540 pulses at 1.25 hertz at a 33.3 percent duty cycle.
Subsequent analysis of motor current data indicated no change to the HGA
configuration.
13. From the period from March 9 to March 11, a navigation cycle was performed.
This navigation cycle provided near-continuous acquisition of two-way doppler
and ranging data during four consecutive passes of the spacecraft over DSS-14,
(Goldstone 70 meter antenna), DSS-42 (Canberra 34 meter antenna), DSS-63, and
then back to DSS-14.
14. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 20 DN
(4.5 volts). The DC measurement reads 140 DN (16.4 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
15. The Spacecraft status as of March 11, 1993, is as follows:
a) System Power Margin - 64 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 10.5rpm/Acquisition Sensor
d) Spacecraft Attitude is approximately 4 degrees
off-sun (lagging) and 8 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna- 1200bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, SSI, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 219 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Trajectory Correction Maneuver (TCM-19) sequence memory load was
approved for transmission by the Project on March 5, 1993. TCM-19 is a one
portion maneuver scheduled to execute on March 9, 1993 consisting of two
axial segments. The estimated total delta velocity for TCM-19 is 2.12 m/sec.
2. The EJ-1 (Earth-Jupiter #1) preliminary sequence and command generation
package was approved by the Project on March 9, 1993. This sequence covers
spacecraft activities from April 12, 1993 to June 14, 1993 and includes the
Radio Relay Antenna (RRA) slew test on April 28, 1993.
GDS (Ground Data Systems):
1. A Galileo GCF (Ground Communication Facility) 1.5 Upgrade Flow Test (CMD)
was performed on March 11, 1993, from 15:00:00 to 17:00:00 GMT using CTA-21
(Compatibility Test Area 21) . The purpose of this test was to perform a
command flow through the SFOC Gateway (SG) to the Error Correction and
Switching (ECS) instead of through the External User Gateway (EUG). This
test exercised command only for Galileo. The MCCC command system
successfully sent commands (directives) to the CPA (Command Processor
Assembly) with performance as expected. The Galileo SCO participated
in this test and reported the flow through the 1.5 GCF upgrade performed
nominally. A retest of the telemetry portion of the GCF 1.5 Upgrade testing
is still planned to take place prior to DSN's (Deep Space Network)
March 15 on-line date.
A Galileo SCP (Station Commuication Processor) test was performed
March 9, 1993, from 08:00:00 to 12:00:00 GMT using CTA-21. The purpose of
this test was to perform a command, telemetry, monitor and tracking flow
through the new version of SCP software that is supporting the GCF 1.5 upgrade.
This test exercised command, telemetry, monitor, and tracking for Galileo.
The test was successful in flowing all data through the new SCP. Performance
was nominal and supported low and high rate telemetry.
A MOSO System test for Galileo MGDS V18.0 Command was performed
March 9, 1993, from 20:00:00 to 01:00:00 GMT using DSS-65 (Madrid 34 meter
antenna). The purpose of this test was to exercise the connectivity of
V18.0 CMD with an actual station (and CPA). The test was successful and
commands and directives were sent to the CPA by MGDS CMD. Approximately 75%
of the MOSO system test objectives were completed and passed; 25% of the test
objectives could not be tested at this time and are scheduled for inclusion
in V18.1. The GLL SCO participated in the test and reported satisfactory
results (including performance). The STR for V18 was held March 10, 1993
and was approved to be used for UAT/GDS testing.
TRAJECTORY
As of noon Thursday, March 11, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 82,596,500 km (0.55 AU)
Distance from Sun 229,680,800 km (1.54 AU)
Heliocentric Speed 106,300 km per hour
Distance from Jupiter 609,095,400 km
Round Trip Light Time 9 minutes, 14 seconds
SPECIAL TOPIC
1. As of March 11, 1993, a total of 67580 real-time commands have been
transmitted to Galileo since Launch. Of these, 62474 were initiated in the
sequence design process and 5106 initiated in the real-time command process.
In the past week, 2481 real time commands were transmitted: 2481 were
initiated in the sequence design process and none initiated in the real time
command process. Major command activities included commands to uplink the
TCM-19 sequence memory load, update acquisition sensor parameters, perform a
wobble compensation, turn the RTG boom heaters off, update AACS parameters,
uplink the 10 rpm spinup mini-sequence, and hammer the HGA motors.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | It's kind of fun to do
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | the impossible.
|_____|/ |_|/ |_____|/ | Walt Disney
|
| 560.769 | Galileo Update -- 03/12/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Mar 16 1993 15:17 | 46 |
| Article 3249 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/12/93
Message-ID: <13MAR199301175296@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Sat, 13 Mar 1993 01:17:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 27
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 12, 1993
The Galileo Spacecraft is operating normally in the all-spin mode at
10.5 rpm, and is transmitting coded telemetry at 1200 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-14 (Goldstone 70 meter antenna), DSS-42 (Canberra 34 meter antenna)
and DSS-63 (Madrid 70 meter antenna).
Today, March 12, 1993, the spacecraft under stored sequence control is
scheduled to spin down to 2.9 rpm. Tracking is scheduled over DSS-14 and
DSS-63.
Over the weekend, spacecraft activity to map the High Gain Antenna
receive gain pattern is scheduled on Saturday. Tracking is scheduled
over DSS-61 (Madrid 34 meter antenna), DSS-14 and DSS-15 (Goldstone 34 meter
antenna) on Saturday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | It's kind of fun to do
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | the impossible.
|_____|/ |_|/ |_____|/ | Walt Disney
|
| 560.770 | Galileo Update -- 03/15/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Mar 16 1993 15:20 | 43 |
| Article 3274 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/15/93
Message-ID: <16MAR199306201799@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Tue, 16 Mar 1993 06:20:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 24
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 15, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Over the weekend, spacecraft activity to map the High Gain Antenna
receive gain pattern was performed on Saturday, as planned. Tracking was
scheduled ver DSS-42 (Canberra 34 meter antenna), DSS-61 (Madrid 34 meter
antenna), DSS-14 (Goldstone 70 meter antenna) and DSS-15 (Goldstone 34 meter
antenna) on Saturday.
Throughout the week ending March 19, 1993, no spacecraft activity is
scheduled. Tracking each day is scheduled over DSS-63 (Madrid 70 meter
antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't ever take a fence
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | down until you know the
|_____|/ |_|/ |_____|/ | reason it was put up.
|
| 560.771 | | SKYLAB::FISHER | That's right...you were there for the grovelling | Wed Mar 17 1993 15:27 | 6 |
| BTW, Ron Baalke said later that the HGA receive pattern test was to see if
the HGA was usable at all given that the hammering had apparently changed
something albeit slightly. There is not much hope that it will be usable,
but they are going to test it.
Burns
|
| 560.772 | Galileo Mission Director Status Rpt 12-18 Mar 93 | CXDOCS::J_BUTLER | E pur, si muove... | Tue Mar 23 1993 14:46 | 112 |
| Article: 3303
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/19/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Fri, 19 Mar 1993 16:46:00 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
March 12 -18, 1993
SPACECRAFT
1. On March 12, as part of the 10 rpm spinup activities, real-time commands
were sent to open the Star Scanner shutter and collect attitude and wobble
data before transitioning to low spin. Commands were then sent to update the
attitude control subsystem parameters to the low spin values.
The spacecraft, under stored sequence control, initiated the spin down
at approximately 2123 UTC and completed at 2149 UTC for a duration of 26
minutes. After the spin down to 2.84 RPM, real-time commands were sent to
enable spin corrects and reduce the spin rate deadband, complete the attitude
control subsystem parameter updates, perform a wobble compensation, and return
to cruise mode (dual-spin at 3.15 RPM). During the spin down, the minus S1A
thruster temperature exhibited an unusual profile. Specifically, approximately
six minutes after the spin-down began, the minus S1A thruster increased in
temperature by 25 degrees C (171.8 degrees C) over approximately three minutes
and then stabilized and subsequently decreased slightly prior to soakback.
The temperatures, however, were well within the safe operating range of the
thrusters.
2. On March 13, the High Gain Antenna (HGA) calibration mini-sequence was
transmitted to the spacecraft without incident. This mini-sequence covered
spacecraft activities on March 14, 1993.
3. On March 14, the HGA uplink RF (Radio Frequency) test activities were
performed on the spacecraft. An X-band uplink signal was transmitted to the
spacecraft with the X-band to S-band Down Converter subsystem (XSDC) turned on.
As the spacecraft turned from 5 to 17 degrees off the Earth, uplink S-band
AGC (Automatic Gain Control) data was collected to determine the presence of
any antenna gain pattern. Analysis of the RF data is in process.
4. On March 15, a NO-OP command was sent to reset the command loss timer to
240 hours, its planned value during this mission phase.
5. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 20 DN
(4.5 volts). The DC measurement reads 144 DN (16.9 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
6. The Spacecraft status as of March 18, 1993, is as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 7 degrees
off-sun (lagging) and 8 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna- 40bps(uncoded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 162 hours
GDS (Ground Data Systems):
1. The March System Engineers Monthly Report (SEMR) review was conducted
Thursday, March 11. A review of current Project and Institutional (DSN and
MOSO) system status was conducted. Near-term delivery schedules, past months
accomplishments and potential problem areas were discussed. No significant
schedule changes or significant problems were reported.
TRAJECTORY
As of noon Thursday, March 18, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 94,267,000 km (0.63 AU)
Distance from Sun 239,247,000 km (1.60 AU)
Heliocentric Speed 103,500 km per hour
Distance from Jupiter 594,763,900 km
Round Trip Light Time 10 minutes, 32 seconds
SPECIAL TOPIC
1. As of March 18, 1993, a total of 67634 real-time commands have been
transmitted to Galileo since Launch. Of these, 62528 were initiated in the
sequence design process and 5106 initiated in the real-time command process.
In the past week, 54 real time commands were transmitted: 54 were initiated
in the sequence design process and none initiated in the real time command
process. Major command activities included commands to open the star scanner,
collect attitude and wobble data, update attitude control subsystem parameters,
enable spin corrects and reduce the spin rate deadband, perform a wobble
compensation, uplink the HGA RF test mini-sequence and reset the command loss
timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't ever take a fence
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | down until you know the
|_____|/ |_|/ |_____|/ | reason it was put up.
|
| 560.773 | Galileo Update -- 03/22/93 | CXDOCS::J_BUTLER | E pur, si muove... | Tue Mar 23 1993 14:47 | 32 |
| Article: 3320
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/22/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Mon, 22 Mar 1993 19:47:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 22, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft or tracking was scheduled.
Today, March 22, 1993, the joint gravity wave experiment with Mars
Observer and Ulysses is scheduled to begin, and will continue through April 12.
Tracking is scheduled over DSS-63 (Madrid 70 meter antenna) and DSS-14
(Goldstone 70 meter antenna).
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-14 and DSS-63 with the gravity wave experiment continuing.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't ever take a fence
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | down until you know the
|_____|/ |_|/ |_____|/ | reason it was put up.
|
| 560.774 | Galileo Update -- 03/24/93 | PONIL::J_BUTLER | E pur, si muove... | Thu Mar 25 1993 13:49 | 46 |
| Article 3332 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/24/93
Message-ID: <24MAR199319384401@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Wed, 24 Mar 1993 19:38:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 27
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
March 24, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting uncoded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid 70
meter antenna).
Today, March 24, 1993, a routine RPM (Retro-Propulsion Module) 10-Newton
thruster flushing maintainence activity and cruise science memory readouts are
scheduled. Real-time commands to switch to 40 bps coded telemetry are also
scheduled. The Gravity Wave Experiment also continues. Tracking is scheduled
over DSS-14 and DSS-63.
Tomorrow, real-time commands are scheduled to update CDS (Command & Data
Subsystem) flight software. Tracking is scheduled over DSS-14 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't ever take a fence
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | down until you know the
|_____|/ |_|/ |_____|/ | reason it was put up.
|
| 560.775 | Mission Director Status Rpt - 19-25 Mar 93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Mar 26 1993 10:46 | 106 |
| Article: 3346
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 03/25/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Fri, 26 Mar 1993 00:31:00 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
March 19 - 25, 1993
SPACECRAFT
1. On March 22 and March 24, a NO-OP command was sent to reset the command
loss timer to 240 hours, its planned value during this mission phase.
2. On March 22, the joint gravity wave experiment with Mars Observer (MO)
and Ulysses (ULS) began. The experiment is scheduled to continue throughout
the EE-12 (Earth-Earth #12) sequence and complete on April 12, 1993.
3. On March 24, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
maintenance activity was performed; all 12 thrusters were flushed during the
activity. Thruster performance throughout the activity was nominal.
4. On March 24 real-time commands were sent to switch from 40 bps uncoded
telemetry to 40 bps coded telemetry. These commands were sent to improve the
data quality of the downlink telemetry.
5. On March 25, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer
(MAG) instruments. Preliminary analysis indicates the data was received
properly.
6. On March 25, real-time commands were sent to update the Command and Data
Subsystem (CDS) flight software. Specifically, the change allows the memory
readout command to perform consecutive memory readouts at 10 bps. The change
modified the number of minor frames each block of data is collected when a
memory readout command is issued.
7. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19 DN
(4.3 volts). The DC measurement reads 148 DN (17.4 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
8. The Spacecraft status as of March 25, 1993, is as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 10 degrees
off-sun (lagging) and 8 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 234 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-1 (Earth-Jupiter #1) preliminary sequence and command generation
package was approved by the Project on March 19, 1993. This sequence covers
spacecraft activity from April 12, 1993 to June 14, 1993 and includes the
Radio Relay Antenna (RRA) slew test on April 28, 1993.
TRAJECTORY
As of noon Thursday, March 25, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 107,167,000 km (0.72 AU)
Distance from Sun 248,844,400 km (1.66 AU)
Heliocentric Speed 100,700 km per hour
Distance from Jupiter 581,121,600 km
Round Trip Light Time 12 minutes, 0 seconds
SPECIAL TOPIC
1. As of March 25, 1993, a total of 67692 real-time commands have been
transmitted to Galileo since Launch. Of these, 62585 were initiated in the
sequence design process and 5107 initiated in the real-time command process.
In the past week, 58 real time commands were transmitted: 57 were initiated
in the sequence design process and one initiated in the real time command
process. Major command activities included commands to reset the command
loss timer, switch to 40 bps coded telemetry and update the CDS flight
software.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't ever take a fence
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | down until you know the
|_____|/ |_|/ |_____|/ | reason it was put up.
|
| 560.776 | Galileo Update -- 04/01/93 | PONIL::J_BUTLER | E pur, si muove... | Fri Apr 02 1993 21:52 | 92 |
| Article 1091 of alt.sci.planetary:
Xref: nntpd2.cxo.dec.com sci.space:60326 sci.astro:34162 alt.sci.planetary:1091
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!dbased.nuo.dec.com!e2big.mko.dec.com!pa.dec.com!decwrl!elroy.jpl.nasa.gov!kelvin.jpl.nasa.gov!baalke
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro,alt.sci.planetary
Subject: Galileo Update - 04/01/93
Date: 2 Apr 1993 00:34 UT
Organization: Jet Propulsion Laboratory
Lines: 75
Distribution: world
Message-ID: <2APR199300342027@kelvin.jpl.nasa.gov>
NNTP-Posting-Host: kelvin.jpl.nasa.gov
Keywords: Galileo, JPL
News-Software: VAX/VMS VNEWS 1.41
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
March 26 - April 1, 1993
SPACECRAFT
1. On March 29, a NO-OP command was sent to reset the command loss timer to
240 hours, its planned value during this mission phase.
2. Throughout this week, there was no spacecraft sequence controlled activity
planned. This period had previously been set aside for possible High Gain
Antenna rib release activities of which none were scheduled.
3. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19 DN
(4.3 volts). The DC measurement reads 151 DN (17.8 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
4. The Spacecraft status as of April 1, 1993, is as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 13 degrees
off-sun (lagging) and 8 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 163 hours
TRAJECTORY
As of noon Thursday, April 1, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 121,242,900 km (0.81 AU)
Distance from Sun 258,439,300 km (1.73 AU)
Heliocentric Speed 98,200 km per hour
Distance from Jupiter 568,132,700 km
Round Trip Light Time 13 minutes, 34 seconds
SPECIAL TOPIC
1. As of April 1, 1993, a total of 67693 real-time commands have been
transmitted to Galileo since Launch. Of these, 62586 were initiated in the
sequence design process and 5107 initiated in the real-time command process.
In the past week, one real time command was transmitted: one was initiated in
the sequence design process and none initiated in the real time command
process. Major command activities included commands to reset the command
loss timer.
2. The Galileo Preliminary Mission/System Design Review for implementation
with the Low Gain Antenna (LGA) was held on March 31, 1993. A comprehensive
and well organized review of the science/mission requirements, and the
spacecraft and ground system design efforts to meet those requirements were
presented.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Being cynical never helps
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to correct the situation
|_____|/ |_|/ |_____|/ | and causes more aggravation
| instead.
|
| 560.777 | | FASDER::ASCOLARO | Anthony Edward, 5/5/92 | Fri Apr 02 1993 22:02 | 5 |
| Have they 100% given up on opening the stuck ribs?
Does anyone know?
Tony
|
| 560.778 | | PONIL::J_BUTLER | E pur, si muove... | Fri Apr 02 1993 22:09 | 7 |
| Re -.1
The special topic #2 in .776 implies that they hold little hope of
freeing the HGA. They'll probably try a few more things, but put
most of their R & D into improving results with the LGA.
JB
|
| 560.779 | Galileo Update -- 04/06/93 | PONIL::J_BUTLER | E pur, si muove... | Wed Apr 07 1993 14:41 | 44 |
| Article 3425 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!elroy.jpl.nasa.gov!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/06/93
Message-ID: <6APR199322594971@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
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Date: Tue, 6 Apr 1993 22:59:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 25
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 6, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft was scheduled. Tracking was schedule over
DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid 70 meter antenna).
Today, April 6, 1993, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-14 and DSS-63.
Tomorrow, real-time commands are scheduled to update a system fault
protection parameter. Also, the LGA (Low Gain Antenna) deploy/retract
mini-sequence is scheduled to be uplinked. Tracking is scheduled over
DSS-14 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Being cynical never helps
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to correct the situation
|_____|/ |_|/ |_____|/ | and causes more aggravation
| instead.
|
| 560.780 | Possible Galileo "Target"...Comet Orbits Jupiter | PONIL::J_BUTLER | E pur, si muove... | Fri Apr 09 1993 14:29 | 211 |
| 0 -- Here's an interesting item Galileo *might* be able able to observe.
--
-- The following exchange took place on USENET in alt.sci.planetary.
-- I have shortened _some_ of the headers and sig files, but (hopefully)
-- left enough to give each author proper recognition.
--
-- Darn, I wish they could open that HGA!
Regards,
John B.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Article 1102 of alt.sci.planetary:
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Comet in Temporary Orbit Around Jupiter?
According the IAU Circular #5744, Comet Shoemaker-Levy 1993e, may be
temporarily in orbit around Jupiter. The comet had apparently made a
close flyby of Jupiter sometime in 1992 resulting in the breakup of the
comet. Attempts to determine the comet's orbit has been complicated by
the near impossibility of measuring the comet's center of mass.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Being cynical never helps
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to correct the situation
|_____|/ |_|/ |_____|/ | and causes more aggravation
| instead.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Article 1106 of alt.sci.planetary:
From: seale@possum.den.mmc.com (Eric H Seale)
Subject: Re: Comet in Temporary Orbit Around Jupiter?
Organization: Martin Marietta Astronautics, Denver
baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:
>According the IAU Circular #5744, Comet Shoemaker-Levy 1993e, may be
>temporarily in orbit around Jupiter. The comet had apparently made a
>close flyby of Jupiter sometime in 1992 resulting in the breakup of the
>comet.
Ooooh -- who would have thought that Galileo would get the chance to
check out a comet TOO?!?
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Article 1108 of alt.sci.planetary:
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Re: Comet in Temporary Orbit Around Jupiter?
Date: 6 Apr 1993 14:57 UT
In article <1993Apr6.061329.25582@den.mmc.com>, seale@possum.den.mmc.com (Eric H Seale) writes...
>baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:
>>According the IAU Circular #5744, Comet Shoemaker-Levy 1993e, may be
>>temporarily in orbit around Jupiter. The comet had apparently made a
>>close flyby of Jupiter sometime in 1992 resulting in the breakup of the
>>comet.
>
>Ooooh -- who would have thought that Galileo would get the chance to
>check out a comet TOO?!?
Comet Gehrels 3, which was discovered in 1977, was determined to have
been in a temporary Jovian orbit from 1970 to 1973. Comet Shoemaker-Levy 1993e
may remain in orbit around Jupiter long enough to allow Galileo to
make some closeup observations. The orbital trajectory for Comet
Shoemaker-Levy is still being determined.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Being cynical never helps
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to correct the situation
|_____|/ |_|/ |_____|/ | and causes more aggravation
| instead.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Article 1110 of alt.sci.planetary:
From: prb@access.digex.com (Pat)
Subject: Re: Comet in Temporary Orbit Around Jupiter?
Date: 6 Apr 1993 13:40:39 -0400
Organization: Express Access Online Communications USA
In article <6APR199314571378@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:
|Comet Gehrels 3, which was discovered in 1977, was determined to have
|been in a temporary Jovian orbit from 1970 to 1973. Comet Shoemaker-Levy 1993e
|may remain in orbit around Jupiter long enough to allow Galileo to
|make some closeup observations. The orbital trajectory for Comet
|Shoemaker-Levy is still being determined.
What about positional uncertainties in S-L 1993e? I assume we know where
and what Galileo is doing within a few meters. But without the
HGA, don't we have to have some pretty good ideas, of where to look
before imaging? If the HGA was working, they could slew around
in near real time (Less speed of light delay). But when they were
imaging toutatis???? didn't someone have to get lucky on a guess to
find the first images?
Also, I imagine S-L 1993e will be mostly a visual image. so how will
that affect the other imaging missions. with the LGA, there is a real
tight allocation of bandwidth. It may be premature to hope for answers,
but I thought i'd throw it on the floor.
pat
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Article 1111 of alt.sci.planetary:
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Re: Comet in Temporary Orbit Around Jupiter?
Date: 6 Apr 1993 19:04 UT
Organization: Jet Propulsion Laboratory
In article <1psfan$pj0@access.digex.net>, prb@access.digex.com (Pat) writes...
>In article <6APR199314571378@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:
>|Comet Gehrels 3, which was discovered in 1977, was determined to have
>|been in a temporary Jovian orbit from 1970 to 1973. Comet Shoemaker-Levy 1993e
>|may remain in orbit around Jupiter long enough to allow Galileo to
>|make some closeup observations. The orbital trajectory for Comet
>|Shoemaker-Levy is still being determined.
>
>What about positional uncertainties in S-L 1993e?
If Comet Shoemaker-Levy 1993e is in Jovian orbit, and if the comet
is still hanging around when Galileo arrives, then I'm sure it will
be added to the list of targets. We'll have by then over two years
of Earth-based observations to help narrow down the positions of the
pieces of the comet. It probably won't be too much different than
what was done with Gaspra.
>But when they were
>imaging toutatis?
Galileo did not image Toutatis. That came from Earth-based radar.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Being cynical never helps
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to correct the situation
|_____|/ |_|/ |_____|/ | and causes more aggravation
| instead.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Article 1113 of alt.sci.planetary:
From: anita@astro.as.utexas.edu (Anita Cochran)
Subject: Re: Comet in Temporary Orbit Around Jupiter?
Organization: Univ. of Texas McDonald Observatory
Date: Wed, 7 Apr 1993 20:00:08 GMT
In article <1pq0jkINNams@news.aero.org>, shag@aero.org (Rob Unverzagt) writes:
> In article <5APR199318045045@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:
> > According the IAU Circular #5744, Comet Shoemaker-Levy 1993e, may be
> > temporarily in orbit around Jupiter. The comet had apparently made a
> > close flyby of Jupiter sometime in 1992 resulting in the breakup of the
> > comet. Attempts to determine the comet's orbit has been complicated by
> > the near impossibility of measuring the comet's center of mass.
> >
>
> Am I missing something -- what does knowing the comet's center
> of mass do for you in orbit determination?
Well, it is the center of mass which is in orbit around anything and normally
that is the cometary nucleus. In normal situations, even though there
is a big bright coma, we can tell where the nucleus is to approximately
1 or 2 arcsec. However, Shoemaker-Levy is not a normal comet but
is one that has been ripped apart by Jupiter (pretty unusual).
The image it presents is cigar shaped about 1 arcmin by 11 arcsec.
There are some discernible knots of brightness but the question is
which is the "nucleus". Actually, they will all continue to orbit
the sun and so we now have multiple mini-comets, all of which need
orbits (they will not stay bound together probably). For previous
split comets, the pieces were more unequal in size so we kept track
of the brightest, presumed biggest.
Now at Jupiter's distance (5au), an object that is 1 arcmin long is
more than 200,000km long. So it is quite relevant to our orbit
calculations that we know where in that 200,000km the nucleus is (are?).
All of the orbit calculations to date have assumed it is in the center,
even though the brightest condensations are not in the center.
If the pieces were to stay together, the dominant error would be
in the perihelion date but since they won't, all bets are off.
--
Anita Cochran uucp: !utastro!anita
arpa: anita@astro.as.utexas.edu
snail: Astronomy Dept., The Univ. of Texas, Austin, TX, 78712
at&t: (512) 471-1471
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Article 1114 of alt.sci.planetary:
From: carl@SOL1.GPS.CALTECH.EDU (Carl J Lydick)
Subject: Re: Comet in Temporary Orbit Around Jupiter?
Date: 8 Apr 1993 05:27:33 GMT
Organization: HST Wide Field/Planetary Camera
In article <1993Apr7.200008.11750@astro.as.utexas.edu>, anita@astro.as.utexas.edu (Anita Cochran) writes:
=The image it presents is cigar shaped about 1 arcmin by 11 arcsec.
Y'know, that description would fit an object with dimensions 1x4x9, if it were
seen from the proper angle. Nah, couldn't be :-).
--------------------------------------------------------------------------------
Carl J Lydick | INTERnet: CARL@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|
| 560.781 | Mission Director Status Rpt -- 2-8 Apr 93 | PONIL::J_BUTLER | E pur, si muove... | Fri Apr 09 1993 20:36 | 132 |
| Article 3460 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/08/93
Message-ID: <9APR199316115490@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
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Lines: 113
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
April 2 - 8, 1993
SPACECRAFT
1. On April 5, a NO-OP command was sent to reset the command loss timer to
240 hours, its planned value during this mission phase.
2. On April 7, real-time commands were sent to modify the system fault
protection in preparation for the Radio Relay Antenna (RRA) slew test
scheduled for April 28. Specifically, a data table was modified to turn the
RRA motors off in the event of unexpected sequence termination.
3. On April 7, the Low Gain Antenna (LGA-2)/Dual Drive Actuator (DDA) hammer
mini-sequence was uplinked to the spacecraft without incident. This
mini-sequence covered spacecraft activities on April 8 and included three
deploy/retracts of the LGA-2 along with a DDA actuation window which began
immediately following the LGA-2 activity.
4. On April 8, under stored sequence control, the LGA-2 was deployed/retracted
three times beginning at 1052 PDT and completing at 1142 PDT. Immediately
following, real-time commands were sent to warm up the High Gain Antenna
(HGA) motors and to hammer the motors for 540 pulses at 1.25 hertz for a
33.3 percent duty cycle. Preliminary analysis of motor current data indicated
no change to the HGA configuration.
5. On April 8, a routine sun vector update was performed. This sun vector is
valid through May 30, 1993.
6. The AC bus imbalance measurement has not exhibited significant change
(greater than 25 DN) throughout this period but the DC bus imbalance
measurement has. The AC measurement reads 19 DN (4.3 volts). The DC
measurement has ranged from 151 DN (17.8 volts) to 63 DN (1.1 volts) and
currently reads 117 DN (13.6 volts). These measurements are consistent with
the model developed by the AC/DC special anomaly team.
7. The Spacecraft status as of April 8, 1993, is as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 16 degrees
off-sun (lagging) and 7 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 240 hours
Time To Initiation - 238 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-2 (Earth-Jupiter #2) Cruise Plan was approved by the Project on
April 6, 1993. This plan covers spacecraft activities from July 6, 1993 to
August 27, 1993 and includes the IDA optical navigation images and the IDA
approach Trajectory Correction Maneuvers (TCMs) number 20 and 21.
2. The EJ-1 sequence memory load was approved for transmission by the Project
on April 8, 1993. This sequence covers spacecraft activities from
April 12, 1993 to June 14, 1993 and includes a window for the RRA slew test on
April 28, 1993.
GDS (Ground Data Systems):
1. Galileo participated in DSN (Deep Space Network) acceptance testing for the
DSN Telemetry Phase 3 Upgrade on April 1, 1993, from 19:00:00 to 23:00:00 GMT,
using CTA-21 (Compatibility Test Area 21). The purpose of this activity was
to test the flow of Galileo telemetry data through the new Telemetry Group
Controller (TGC) and the Telemetry Channel Assembly (TCA). The TGC/TCA
is the replacement for the current Telemetry Processing Assembly (TPA). The
test was started late due to the prior Voyager test running overtime. A TSA
(Telmetry Simulation Assembly) problem delayed the flow of data further, and
consequently only one telemetry rate was run (40 bps ESS) along with monitor
data. A retest is scheduled for April 13, 1993. MVT (Mission Verification
Test) of this system is expected to begin May 16, 1993.
TRAJECTORY
As of noon Thursday, April 8, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 136,414,000 km (0.91 AU)
Distance from Sun 268,004,800 km (1.79 AU)
Heliocentric Speed 95,700 km per hour
Distance from Jupiter 555,761,800 km
Round Trip Light Time 15 minutes, 14 seconds
SPECIAL TOPIC
1. As of April 8, 1993, a total of 70177 real-time commands have been
transmitted to Galileo since Launch. Of these, 65070 were initiated in
the sequence design process and 5107 initiated in the real-time command
process. In the past week, 2484 real time commands were transmitted: 2484
were initiated in the sequence design process and none initiated in the real
time command process. Major command activities included commands to reset the
command loss timer, modify system fault protection, load the LGA/DDA hammer
mini-sequence, warm up and hammer the HGA motors, and update the sun vector.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Being cynical never helps
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to correct the situation
|_____|/ |_|/ |_____|/ | and causes more aggravation
| instead.
|
| 560.782 | Galileo Update -- 04/12/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Apr 13 1993 16:46 | 43 |
| Article 3486 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!elroy.jpl.nasa.gov!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/12/93
Message-ID: <12APR199321015205@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Mon, 12 Apr 1993 21:01:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 24
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 12, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid
70 meter antenna).
Today, April 12, 1993, cruise science memory readouts along with an
USO (Ultra Stable Oscillator) test are scheduled. Tracking is scheduled over
DSS-63.
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Being cynical never helps
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to correct the situation
|_____|/ |_|/ |_____|/ | and causes more aggravation
| instead.
|
| 560.783 | Galileo Update -- 04/14/93 | PONIL::J_BUTLER | E pur, si muove... | Thu Apr 15 1993 13:29 | 42 |
| Article 3497 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!elroy.jpl.nasa.gov!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/14/93
Message-ID: <14APR199318303066@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
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Lines: 23
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 14, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity or tracking was scheduled.
Today, April 14, 1993, a mod index telecommunications test is scheduled.
Tracking is scheduled over DSS-61 (Madrid 34 meter antenna).
Tomorrow, cruise science memory readouts along with a routine RPM
(Retro-Propulsion Module) thruster flushing maintainence activity are
scheduled. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Being cynical never helps
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to correct the situation
|_____|/ |_|/ |_____|/ | and causes more aggravation
| instead.
|
| 560.784 | What if???? | KAOFS::R_YURKIW | reward those who bring bad news!! | Thu Apr 15 1993 15:25 | 11 |
| Interesting thought.
Given the problems with the HGA what would the mission impact be if the
probe failed to detach when it comes time. If I understand correctly
the probe sits right over the braking motor for orbital insertion.
would this mean that they would fly right on past jupiter if the probe
was in the way?
Just a thought. hopefully not a prediction of things to come.
Roger
|
| 560.785 | | HELIX::MAIEWSKI | | Thu Apr 15 1993 17:03 | 12 |
| RE <<< Note 560.784 by KAOFS::R_YURKIW "reward those who bring bad news!!" >>>
> would [a stuck probe] mean that they would fly right on past Jupiter if the
> probe was in the way?
Yes you are correct. The probe is in the way of the breaking motor. A stuck
probe would mean a rather undramatic fly by.
While anything is possible, that's pretty unlikely. NASA has had very few
problems staging.
George
|
| 560.786 | Mission Director Status Rpt 9-15 Apr 93 | TINCUP::J_BUTLER | E pur, si muove... | Mon Apr 19 1993 15:48 | 132 |
| Article 3506 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!purdue!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/15/93
Message-ID: <15APR199321175725@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
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Date: Thu, 15 Apr 1993 21:17:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 113
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
April 9 - 15, 1993
SPACECRAFT
1. On April 9, real-time commands were sent, as planned, to reacquire
celestial reference after completion of the Low Gain Antenna (LGA-2)
swing/Dual Drive Actuator (DDA) hammer activities.
2. On April 9, the EJ-1 (Earth-Jupiter #1) sequence memory load was uplinked
to the spacecraft without incident. This sequence covers spacecraft activity
from April 12, 1993 to June 14, 1993 and includes a window for the Radio Relay
Antenna (RRA) slew test on April 28, 1993. The command loss timer was set to
11 days as a part of this sequence memory load.
3. On April 12 and 15, a NO-OP command was sent to reset the command loss
timer to 264 hours, its planned value during this mission phase.
4. On April 12, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer
(MAG) instruments. Preliminary analysis indicates the data was received
properly.
5. On April 12, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect gravitational red shift experiment
data; long term trend analysis is continuing.
6. On April 14, a 40bps modulation index test was performed to determine the
optimal Signal-to-Noise Ratio (SNR) when transmitting at 40bps. Preliminary
analysis of the data suggests that the present pre-launch selected modulation
index is near the optimal level.
7. On April 15, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV) and Magnetometer (MAG) instrument.
Preliminary analysis indicates the data was received properly.
8. On April 15, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed; all 12 thrusters were flushed
during the activity. Thruster performance throughout the activity was nominal.
9. The AC/DC bus imbalance measurements have not exhibited significant
changes (greater than 25 DN) throughout this period. The AC measurement reads
19 DN (4.3 volts). The DC measurement reads 111 DN (12.9 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
10. The Spacecraft status as of April 15, 1993, is as follows:
a) System Power Margin - 60 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 18 degrees
off-sun (lagging) and 6 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 260 hours
GDS (Ground Data Systems):
1. Galileo participated in a second DSN (Deep Space Network) acceptance test
for the DSN Telemetry Phase 3 Upgrade on April 13, 1993, using CTA-21
(Compatibility Test Area 21). The purpose of this test was to verify
the flow of Galileo telemetry data through the new Telemetry Group Controller
(TGC) and the Telemetry Channel Assembly (TCA). The TGC/TCA is the replacement
for the current Telemetry Processing Assembly (TPA). Seven different telemetry
rates were run for this test; all ran well on both the MTS (MCCC Telemetry
Subsystem) and the AMMOS MGDS V18.0 GIF with the exception of 10bps. The
10bps rate had some trouble staying in lock; it appears the TGC/TCA was
not metering the data correctly. Further comparisons between the MGDS and MTS
data from this test are being conducted. MVT (Mission Verification Test) of
the TGC/TCA system is expected to begin May 16, 1993.
TRAJECTORY
As of noon Thursday, April 15, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 152,606,000 km (1.02 AU)
Distance from Sun 277,519,800 km (1.86 AU)
Heliocentric Speed 93,400 km per hour
Distance from Jupiter 543,973,900 km
Round Trip Light Time 17 minutes, 4 seconds
SPECIAL TOPIC
1. As of April 15, 1993, a total of 70184 real-time commands have been
transmitted to Galileo since Launch. Of these, 65076 were initiated in the
sequence design process and 5108 initiated in the real-time command process.
In the past week, 7 real time commands were transmitted: 6 were initiated in
the sequence design process and one initiated in the real time command process.
Major command activities included commands to reacquire celestial reference,
uplink the EJ-1 sequence memory load, and reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Being cynical never helps
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | to correct the situation
|_____|/ |_|/ |_____|/ | and causes more aggravation
| instead.
|
| 560.787 | Galileo Update -- 04/19/93 | PONIL::J_BUTLER | E pur, si muove... | Wed Apr 21 1993 14:03 | 42 |
| Article 3533 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/19/93
Message-ID: <19APR199318390368@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Mon, 19 Apr 1993 18:39:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 23
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 19, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking
was scheduled over DSS-63 (Madrid 70 meter antenna).
Today, April 19, 1993, telecommunication tests along with cruise science
memory readouts are scheduled. Tracking is scheduled over DSS-61 (Madrid 34
meter antenna) and DSS-63.
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The aweto from New Zealand
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | is part caterpillar and
|_____|/ |_|/ |_____|/ | part vegetable.
|
| 560.788 | | IAMNRA::SULLIVAN | Stephanie! quantum mutatus ab illo | Wed Apr 21 1993 14:35 | 7 |
| A while back there was something about getting a pattern of radiation from the
high-gain antenna. I don't recall seeing any results, but wondered if it might
be at least somewhat usable even though not fully deployed... maybe at least
a little better than the low gain antenna... ?
Thanks,
-SES
|
| 560.789 | Galileo Update -- 04/21/93 | PONIL::J_BUTLER | E pur, si muove... | Fri Apr 23 1993 17:30 | 42 |
| Article 3535 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/21/93
Message-ID: <21APR199318512672@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Wed, 21 Apr 1993 18:51:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 23
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 21, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity or tracking was scheduled.
Today, April 21, 1993, a suppressed carrier DSN (Deep Space Network)
advanced receiver test is scheduled. Tracking is scheduled over DSS-14
(Goldstone 70 meter antenna).
Tomorrow, a delta-DOR (Differential One-Way Ranging) pass is scheduled
over DSS-14 and DSS-63 (Madrid 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The aweto from New Zealand
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | is part caterpillar and
|_____|/ |_|/ |_____|/ | part vegetable.
|
| 560.790 | Galileo Update -- 04/22/93 | PONIL::J_BUTLER | E pur, si muove... | Fri Apr 23 1993 17:35 | 43 |
| Article 3538 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/22/93
Message-ID: <22APR199317021464@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
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Date: Thu, 22 Apr 1993 17:02:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 25
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 22, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, a suppressed carrier DSN (Deep Space Network) advanced receiver
test was performed, as planned. Tracking was scheduled over DSS-14
(Goldstone 70 meter antenna).
Today, April 22, 1993, a delta-DOR (Differential One-Way Range) pass is
scheduled over DSS-14 and DSS-63 (Madrid 70 meter antenna).
Tomorrow, a cruise science memory readout and power spare relay set
activities are planned. Also, a delta-DOR pass is scheduled. Tracking is
schedule over DSS-63, DSS-14 and DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The aweto from New Zealand
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | is part caterpillar and
|_____|/ |_|/ |_____|/ | part vegetable.
|
| 560.791 | Mission Director Status Rpt 16-22 Apr 93 | PONIL::J_BUTLER | E pur, si muove... | Fri Apr 23 1993 17:37 | 101 |
| Article 3540 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update #2 - 04/22/93
Message-ID: <22APR199322595405@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
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Date: Thu, 22 Apr 1993 22:59:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 84
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
April 16 - 22, 1993
SPACECRAFT
1. On April 19, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer
(MAG) instruments. Preliminary analysis indicates the data was received
properly.
2. On April 19, a Command Detector Unit Signal-to-Noise Ratio (CDUSNR) test
and a Radio Frequency Subsystem Automatic Gain Control (RFSAGC) test were
performed using the LGA-1 (Low Gain Antenna #1) over DSS-63 (Madrid 70 meter
antenna) and DSS-61 (Madrid 34 meter antenna), respectively. Data analysis
is in process. These tests are periodically performed to provide detailed
information relative to the telecom command hardware integrity.
3. On April 19, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value during this mission phase.
4. On April 21, the first of two suppressed carrier/DSN (Deep Space Network)
advanced receiver characterization tests was performed over DSS-14 (Goldstone
70 meter antenna). The spacecraft modulation index was varied from 43 degrees
to 90 degrees for a range of ground receiver bandwidth settings.
5. The AC bus imbalance measurement has not exhibited significant change
(greater than 25 DN) throughout this period but the DC bus imbalance
measurement has. The AC measurement reads 20 DN (4.5 volts). The DC
measurement has ranged from 43 DN (4.6 volts) to 138 DN (16.2 volts) and
currently reads 138 DN (16.2 volts). These measurements are consistent with
the model developed by the AC/DC special anomaly team.
6. The Spacecraft status as of April 22, 1993, is as follows:
a) System Power Margin - 68 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 21 degrees
off-sun (lagging) and 5 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 184 hours
TRAJECTORY
As of noon Thursday, April 22, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 169,747,800 km (1.14 AU)
Distance from Sun 286,967,900 km (1.92 AU)
Heliocentric Speed 91,200 km per hour
Distance from Jupiter 532,735,900 km
Round Trip Light Time 18 minutes, 58 seconds
SPECIAL TOPIC
1. As of April 22, 1993, a total of 70185 real-time commands have been
transmitted to Galileo since Launch. Of these, 65077 were initiated in the
sequence design process and 5108 initiated in the real-time command process.
In the past week, one real time command was transmitted: one was initiated in
the sequence design process and none initiated in the real time command
process. The only command activity was a command to reset the command loss
timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The aweto from New Zealand
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | is part caterpillar and
|_____|/ |_|/ |_____|/ | part vegetable.
|
| 560.792 | Galileo Update -- 04/26/93 | PONIL::J_BUTLER | E pur, si muove... | Tue Apr 27 1993 13:42 | 44 |
| Article 3597 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/26/93
Message-ID: <26APR199320550972@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
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Date: Mon, 26 Apr 1993 20:55:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 27
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 26, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna).
Today, April 26, 1993, cruise science memory readouts are scheduled.
The Radio Relay Antenna is scheduled to be moved forward and then reversed in
preparation for the Radio Relay Antenna slew test scheduled for April 28.
The sequence memory load for the April 28 test is then scheduled for uplink.
Tracking is scheduled over DSS-63 (Madrid 70 meter antenna)and DSS-14
(Goldstone 70 meter antenna).
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-14, DSS-43 and DSS-61 (Madrid 34 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The aweto from New Zealand
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | is part caterpillar and
|_____|/ |_|/ |_____|/ | part vegetable.
|
| 560.793 | Galileo Update -- 04/28/93 | CXDOCS::J_BUTLER | E pur, si muove... | Thu Apr 29 1993 14:41 | 43 |
| Article 3620 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/28/93
Message-ID: <28APR199317310061@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
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Date: Wed, 28 Apr 1993 17:31:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 24
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
April 28, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-14 (Goldstone 70 meter antenna) and DSS-43 (Canberra 70 meter
antenna).
Today, April 28, 1993, the Radio Relay Antenna slew test sequence is
scheduled to execute. Tracking is scheduled over DSS-63 (Madrid 70 meter
antenna) and DSS-61 (Madrid 34 meter antenna).
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The aweto from New Zealand
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | is part caterpillar and
|_____|/ |_|/ |_____|/ | part vegetable.
|
| 560.794 | Mission Director Status Rpt 23-29 Apr 1993 | PONIL::J_BUTLER | E pur, si muove... | Mon May 03 1993 14:26 | 154 |
| Article 3633 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 04/29/93
Message-ID: <29APR199321583849@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
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Date: Thu, 29 Apr 1993 21:58:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 135
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
April 23 - 29, 1993
SPACECRAFT
1. On April 22 and 23, delta Differenced One-way Range (DOR) passes were
performed over DSS-14/63 (Goldstone/Madrd 70 meter antennas) and DSS-14/43
(Goldstone/Canberra 70 meter antennas), respectively. Initial results
indicate the delta DOR pass on April 22 was unsuccessful due to ground
station hardware problems but the one on April 23 was successfully performed.
2. On April 23, a cruise science Memory Readout (MRO) was performed for the
Magnetometer (MAG) instrument. Analysis indicates the data was received
properly.
3. On April 23, the spare power relay contacts were commanded closed via the
spacecraft stored sequence. These relays were commanded closed by the CDS
(Command Data Subsystem) prior to launch and were again commanded closed to
preclude the possibility at Jupiter of the PPS relays/wiring being a
source of internal electrostatic charge (IESD).
4. On April 26, cruise science Memory Readouts (MRO) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer
(MAG) instruments. Preliminary analysis indicates the data was received
properly.
5. During the period from April 26 to April 27, a navigation cycle was
performed. This navigation cycle provided near-continuous acquisition of
two-way doppler and ranging data during three consecutive passes of the
spacecraft over DSS-63, DSS-14, and DSS-43.
6. On April 26, real-time commands were sent to test slew the Radio Relay
Antenna (RRA) in preparation for the mini-sequence slew test on April 28.
The RRA was slewed from approximately 3.5 degrees from stow to approximately
20.3 degrees. Preliminary analysis indicated the antenna slewed to about 18
degrees which was well within the predicted range. The RRA was commanded back
to approximately 15.2 degrees from stow. Preliminary analysis indicated the
antenna reached about 15.8 degrees also well within the predicted range. The
RRA motor temperature was at 1 degree C at the start of the activity and had
increased to 1.6 degrees C at its completion.
After verifying proper RRA slewing, the RRA slew test mini-sequence was
uplinked to the spacecraft for execution on April 28. Upon successful uplink,
a Delayed Action Command (DAC) was sent which will reposition the stator on
May 4 to its initial pre-test position. Also, a DAC was sent to turn the
Two-Way Noncoherent (TWNC) on April 28 prior to the start of the RRA slew test
mini-sequence.
7. On April 27, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value during this mission phase.
8. On April 28, the RRA slew test executed nominally. The spacecraft under
stored sequence control performed six RRA slews starting at about 16 degrees
from stow and going to 53 degrees, back to 25 degrees, then to 51 degrees,
back to 22 degrees, then to 48 degrees and then back to 21 degrees. All of
the slews were well within the predicted range. The RRA motor temperature was
at 2.3 degrees C at the start of the activity and had increased to 4.4
degrees C at its completion. After completion of the RRA slews, real-time
commands were sent to reconfigure back to the pre-test configuration.
9. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 17 DN
(3.9 volts). The DC measurement reads 134 DN (15.7 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
10. The Spacecraft status as of April 29, 1993, is as follows:
a) System Power Margin - 75 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 23 degrees
off-sun (lagging) and 4 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 203 hours
GDS (Ground Data Systems):
1. The first Galileo-GDS test of the MGDS V18.0 Command System (CMD) took
place April 27, 1993 with DSS-61 (Madrid 34 meter antenna). The test went
well and demonstrated that the new command system interfaced with the new DSN
(Deep Space Network) Group 5 Command Processor Assembly (CPA). The test was
successful and the next test for V18.0 CMD is scheduled for May 1, 1993 with
DSS-15 (Goldstone 34 meter antenna).
2. The April System Engineers Monthly Report(SEMR)/Ground System Development
Office (GSDO) MMR was conducted Thursday, April 29. A review of current
Project and Institutional (DSN and MOSO) system status was conducted. On-going
cruise development plus the GSDO Phase 1 and 2 delivery schedules, past months
accomplishments and potential problem areas were discussed. No significant
schedule changes or significant problems were reported.
TRAJECTORY
As of noon Thursday, April 29, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 187,745,300 km (1.26 AU)
Distance from Sun 296,335,800 km (1.98 AU)
Heliocentric Speed 89,100 km per hour
Distance from Jupiter 522,015,800 km
Round Trip Light Time 20 minutes, 58 seconds
SPECIAL TOPIC
1. As of April 29, 1993, a total of 70259 real-time commands have been
transmitted to Galileo since Launch. Of these, 65150 were initiated in the
sequence design process and 5109 initiated in the real-time command process.
In the past week, 74 real time commands were transmitted: 73 were initiated
in the sequence design process and one initiated in the real time command
process. Major command activities included commands to perform the initial
RRA slew test, uplink the RRA slew test mini-sequence, DACs to reposition the
stator and turn the TWNC on, reset the command loss timer, and execute the
RRA slew test.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The aweto from New Zealand
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | is part caterpillar and
|_____|/ |_|/ |_____|/ | part vegetable.
|
| 560.795 | Galileo Update -- 05/03/93 | PONIL::J_BUTLER | E pur, si muove... | Tue May 04 1993 13:43 | 44 |
| Article 3674 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/03/93
Message-ID: <3MAY199322132181@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
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Date: Mon, 3 May 1993 22:13:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 25
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 3, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-14 (Goldstone 70 meter antenna) on Saturday. No tracking
was scheduled on Sunday.
Today, May 3, 1993, cruise science memory readouts and a USO (Utra-
Stable Oscillator) test are scheduled. Tracking is scheduled over DSS-63
(Madrid 70 meter antenna).
Tomorrow, a routine RPM (Retro-Propulsion Module) thruster flushing
maintenance is scheduled. Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Once a year, go someplace
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you've never been before.
|_____|/ |_|/ |_____|/ |
|
| 560.796 | Galileo Update -- 05/04/93 | PONIL::J_BUTLER | E pur, si muove... | Wed May 05 1993 14:03 | 43 |
| Article 3683 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/04/93
Message-ID: <4MAY199323490903@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Tue, 4 May 1993 23:49:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 24
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 4, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, cruise science memory readouts and a USO (Utra-Stable
Oscillator) test were performed. Tracking was scheduled over DSS-63 (Madrid
70 meter antenna).
Today, May 4, 1993, a routine RPM (Retro-Propulsion Module) thruster
flushing maintenance and SITURN is scheduled. Tracking is scheduled over
DSS-63.
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Once a year, go someplace
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you've never been before.
|_____|/ |_|/ |_____|/ |
|
| 560.797 | Mission Director Status Rpt -- 30 Apr - 6 May 93 | PONIL::J_BUTLER | E pur, si muove... | Thu May 06 1993 19:30 | 126 |
| Article 3700 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/06/93
Message-ID: <6MAY199318210774@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Thu, 6 May 1993 18:21:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 107
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
April 30 - May 6, 1993
SPACECRAFT
1. On April 30, a cruise science Memory Readout (MRO) was performed for the
Magnetometer (MAG) instrument. Analysis indicates the data was received
properly.
2. On April 30, a command threshold test and a Radio Frequency Subsystem
Tracking Loop Capacitor (RFSTLC) test were performed over DSS-63 (Madrid
70 meter antenna). Data analysis is in progress. These tests are periodically
performed to provide detailed information relative to the telecom command
hardware integrity.
3. On May 3, a NO-OP command was sent to reset the command loss timer to 264
hours, its planned value for this mission phase.
4. On May 3, cruise science Memory Readouts (MROs) were performed for the
Magnetometer (MAG) and Dust Detector (DDS) instruments. Preliminary analysis
indicates the data was received properly.
5. On May 3, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect gravitational red shift experiment
data; long term trend analysis is continuing.
6. On May 4, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed; all 12 thrusters were flushed
during the activity. Thruster performance throughout the activity was nominal.
7. On May 4, the spacecraft under stored sequence control performed about a
six-degree unbalanced SITURN for the purpose of attitude maintenance. The Z
thrusters were used during the activity.
8. On May 4, a cruise science Memory Readout (MRO) was performed for the
Extreme Ultraviolet Spectrometer (EUV) instrument. Analysis indicates the
data was received properly.
9. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 144 DN (16.9 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
10. The Spacecraft status as of May 6, 1993, is as follows:
a) System Power Margin - 73 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 20 degrees
off-sun (lagging) and 6 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 184 hours
GDS (Ground Data Systems):
1. Two Galileo GDS tests of MGDS V18.0 CMD took place May 1, 1993, with
DSS-61 (Madrid 34 meter antenna) and May 3, 1993, with CTA-21 (Compatibility
Test Area lab at JPL). The test with DSS-15 (Goldstone 34 meter antenna) was
canceled due to configuration problems on the MOSO test string. The second
test with CTA-21 was unsuccessful due to GCF (Ground Communications
Facility) or CTA-21 problems causing command files to have checksum errors
upon transmission to the CPA (Command Processor Assembly). Resolution of the
CTA-21 test problem is expected during the Friday, May 7 retest with CTA-21.
The next GDS tests for V18.0 CMD will be May 7, 1993 with DSS-42 (Canberra
34 meter antenna) and CTA-21.
TRAJECTORY
As of noon Thursday, May 6, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 206,494,200 km (1.38 AU)
Distance from Sun 305,613,600 km (2.04 AU)
Heliocentric Speed 87,100 kour
Distance from Jupiter 511,783,400 km
Round Trip Light Time 23 minutes, 4 seconds
SPECIAL TOPIC
1. As of May 6, 1993, a total of 70260 real-time commands have been
transmitted to Galileo since Launch. Of these, 65151 were initiated in the
sequence design process and 5109 initiated in the real-time command process.
In the past week, one real time command was transmitted and was initiated in
the sequence design process. Major command activities included a command to
reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Once a year, go someplace
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you've never been before.
|_____|/ |_|/ |_____|/ |
|
| 560.799 | Re.-1 Wrong note | MAYDAY::ANDRADE | The sentinel (.)(.) | Fri May 07 1993 14:41 | 1 |
| Mars Observer ... isn't this the Galileo note !!!
|
| 560.800 | Identity Crisis! | PONIL::J_BUTLER | E pur, si muove... | Fri May 07 1993 15:07 | 15 |
| MRO failure! SITURN needed!!! Momentum wheel desat!!
<SET_COMMAND_LOSS_TIMER>(ZERO)
<SET_CONTINGENCY_MODE>(ON)
Now THAT was a REAL LOS (Loss of Signal!)
Sorry! I deleted 560.799 and moved it to 528.155.
Now EVERYONE knows why I'm not a neurosurgeon! :) :)
Regards,
John B.
|
| 560.801 | Galileo Update -- 05/07/93 | PONIL::J_BUTLER | E pur, si muove... | Mon May 10 1993 13:43 | 44 |
| Article 3712 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/07/93
Message-ID: <7MAY199322573065@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Fri, 7 May 1993 22:57:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 25
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 7, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity or tracking was scheduled.
Today, May 7, 1993, a cruise science memory readout was performed. The
second suppressed carrier DSN (Deep Space Network) advanced receiver test is
scheduled. Tracking is scheduled over DSS-43 (Canberra 70 meter antenna),
DSS-14 (Goldstone 70 meter antenna) and DSS-15 (Goldstone 34 meter antenna).
Over the weekend, the suppressed carrier DSN advanced receiver test is
scheduled to complete on Saturday morning. Tracking is scheduled over DSS-14
and DSS-15.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Once a year, go someplace
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you've never been before.
|_____|/ |_|/ |_____|/ |
|
| 560.802 | Galileo Update -- 05/10/93 | PONIL::J_BUTLER | E pur, si muove... | Tue May 11 1993 13:32 | 44 |
| Article 3722 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/10/93
Message-ID: <10MAY199321022800@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Mon, 10 May 1993 21:02:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 25
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 10, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode
and is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, the suppressed carrier DSN (Deep Space Network)
advanced receiver test was completed on Saturday morning, as planned.
Tracking was scheduled over DSS-14 (Goldstone 70 meter antenna) and DSS-15
(Goldstone 34 meter antenna).
Today, May 10, 1993, cruise science memory readouts are scheduled.
Also, and USO (Ultra-Stable Oscillator) test is scheduled. Tracking is
scheduled over DSS-63 (Madrid 70 meter antenna).
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Once a year, go someplace
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you've never been before.
|_____|/ |_|/ |_____|/ |
|
| 560.803 | Mission Director Status Report -- 07-13 May 1993 | CXDOCS::J_BUTLER | E pur, si muove... | Fri May 14 1993 16:49 | 108 |
| Article: 3745
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/13/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Thu, 13 May 1993 22:51:00 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
May 7 - 13, 1993
SPACECRAFT
1. On May 7, a cruise science Memory Readout (MRO) was performed for the
Magnetometer (MAG) instrument. Analysis indicates the data was received
properly.
2. On May 7, the second of two suppressed carrier/DSN (Deep Space Network)
advanced receiver characterization tests was performed over DSS-14 and DSS-15
(Goldstone 70 and 34 meter antennas). The spacecraft modulation index was
varied from 43 degrees to 90 degrees for a range of ground receiver bandwidth
settings. The test ran nominally and data analysis is in progress.
3. On May 10, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
4. On May 10, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer
(MAG) instruments. Preliminary analysis indicates the data was received
properly.
5. On May 10, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect gravitational red shift experiment
data; long term trend analysis is continuing.
6. On May 13, a cruise science Memory Readout (MRO) was performed for the
Magnetometer (MAG) instrument. Preliminary analysis indicates the data was
received properly.
7. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19 DN
(4.3 volts). The DC measurement reads 148 DN (17.4 volts). These measurements \
are consistent with the model developed by the AC/DC special anomaly team.
8. The Spacecraft status as of May 13, 1993, is as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 22 degrees
off-sun (lagging) and 5 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 184 hours
GDS (Ground Data Systems) :
1. Two Galileo Ground Data System (GDS) tests of MGDS V18.0 CMD took place
May 7, 1993 with DSS-42 (Canberra 34 meter antenna) and CTA-21 (Compatibility
Test Area at JPL). The test with V18.0 CMD over DSS-42 was successful. The
second test with CTA-21 was unsuccessful due to GCF (Ground Communications
Facility) routing problems causing command files to have checksum errors upon
transmission to the CPA (Command Processor Assembly). This routing problem
caused two blocks to be transmitted to CTA-21 from the CCP. This was strictly
a GCF configuration problem with CTA-21 only. This problem was not seen on
tests with actual DSS stations.
2. A test review of GDS testing for V18.0 was conducted on May 11, 1993.
A formal GDS test report for GDS/UAT testing will be released by May 21, 1993.
TRAJECTORY
As of noon Thursday, May 13, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 225,906,200 km (1.51 AU)
Distance from Sun 314,793,300 km (2.11 AU)
Heliocentric Speed 85,200 km per hour
Distance from Jupiter 502,010,500 km
Round Trip Light Time 25 minutes, 14 seconds
SPECIAL TOPIC
1. As of May 13, 1993, a total of 70261 real-time commands have been
transmitted to Galileo since Launch. Of these, 65152 were initiated in the
sequence design process and 5109 initiated in the real-time command process.
In the past week, one real time command was transmitted and was initiated in
the sequence design process. Major command activities included a command to
reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Once a year, go someplace
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | you've never been before.
|_____|/ |_|/ |_____|/ |
|
| 560.804 | Galileo Update -- 05/18/93 | CXDOCS::J_BUTLER | E pur, si muove... | Wed May 19 1993 16:28 | 32 |
| Article: 3766
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/18/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Tue, 18 May 1993 20:17:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 18, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, cruise science memory readouts were performed, as planned.
Tracking was scheduled over DSS-63 (Madrid 70 meter antenna).
Today, May 18, 1993, no spacecraft activity or tracking is scheduled.
Tomorrow, real-time commands are scheduled to reposition the Radio Relay
Antenna from approximately 18 degrees to 5 degrees from the stow position and
to reconfigure system fault protection parameters. Tracking is scheduled over
DSS-63 and DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never laugh at anyone's
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | dreams.
|_____|/ |_|/ |_____|/ |
|
| 560.805 | Galileo Update -- 05/19/93 | CXDOCS::J_BUTLER | E pur, si muove... | Thu May 20 1993 14:00 | 33 |
| Article: 3776
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/19/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Wed, 19 May 1993 23:14:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 19, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity or tracking was scheduled.
Today, May 19, 1993, real-time commands are being sent to reposition the
Radio Relay Antenna from approximately 18 degrees to 5 degrees from the stow
position and to reconfigure system fault protection parameters. Tracking is
scheduled over DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone 70
meter antenna).
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never laugh at anyone's
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | dreams.
|_____|/ |_|/ |_____|/ |
|
| 560.806 | Mission Director Status Report - 14-20 May 1993 | CXDOCS::J_BUTLER | E pur, si muove... | Fri May 21 1993 20:47 | 103 |
| Article: 1327
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space,sci.astro,alt.sci.planetary
Subject: Galileo Update - 05/21/93
Date: 21 May 1993 20:20 UT
Organization: Jet Propulsion Laboratory
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
May 14 - 20, 1993
SPACECRAFT
1. On May 17, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer
(MAG) instruments. Preliminary analysis indicates the data was received
properly.
2. On May 17, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
3. During the period from May 19 to May 21, a navigation cycle was performed.
This navigation cycle is providing near-continuous acquisition of two-way
doppler and ranging data during four consecutive passes of the spacecraft over
DSS-63 (Madrid 70 meter antenna), DSS-14 (Goldstone 70 meter antenna), DSS-43
(Canberra 70 meter antenna), and then back to DSS-63.
4. On May 19, in preparation for repositioning the Radio Relay Antenna (RRA),
real-time commands were sent to turn the Two-Way Noncoherent (TWNC) on for the
activity. Commands were then sent to update the variable telemetry packets.
Commands were then sent to slew the RRA from about 18.5 degrees from stow to
approximately 5 degrees from stow. The slew executed nominally. Preliminary
analysis indicates the RRA is between 5.5 and 7.0 degrees from stow. After
completion of the slew, real-time commands were sent to reconfigure back to the
original spacecraft configuration. Commands were also sent to restore a
System Fault Protection (SFP) table to its pre-RRA potentiometer calibration
activity state.
5. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19 DN
(4.3 volts). The DC measurement reads 150 DN (17.7 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
6. The Spacecraft status as of May 20, 1993, is as follows:
a) System Power Margin - 72 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 24 degrees
off-sun (lagging) and 3 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 240 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-2 (Earth-Jupiter #2) Final Profile Design was approved by the
Project on May 20, 1993. This sequence covers spacecraft activities from
July 6, 1993 to August 27, 1993 and includes the IDA optical navigation
images and the IDA approach Trajectory Correction Maneuvers (TCMs) Nos. 20
and 21.
TRAJECTORY
As of noon Thursday, May 20, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 245,899,200 km (1.64 AU)
Distance from Sun 323,869,100 km (2.17 AU)
Heliocentric Speed 83,400 km per hour
Distance from Jupiter 492,670,100 km
Round Trip Light Time 27 minutes, 26 seconds
SPECIAL TOPIC
1. As of May 20, 1993, a total of 70361 real-time commands have been
transmitted to Galileo since Launch. Of these, 65250 were initiated in the
sequence design process and 5111 initiated in the real-time command process.
In the past week, 100 real time commands were transmitted; 98 were initiated
in the sequence design process and 2 initiated in the real-time command
process. Major command activities included commands to reset the command loss
timer, turn the TWNC on and off, reposition the RRA, and update a SFP table.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never laugh at anyone's
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | dreams.
|_____|/ |_|/ |_____|/ |
|
| 560.807 | | FASDER::ASCOLARO | Mountain Jam | Fri May 21 1993 22:49 | 7 |
| I sort of hate to keep asking this, but is there ANY effort going on to
free the HGA?
It is beginning to look like to me that they have stopped 100% trying
to open it.
Tony
|
| 560.808 | The Focus is on the LGA now | CXDOCS::J_BUTLER | E pur, si muove... | Mon May 24 1993 13:41 | 14 |
| From what I hear they have (more or less) written off the HGA and
are putting their efforts into getting the most out of the LGA.
Most of the science data will be returned, including all of the
probe data, but less than 40% of the planned images will be accomplished.
...unless they can figure out how to increase the useful rate of the LGA
or pack more data into 40 bps.
Disappointing, but not a bust by any means!
Regards,
John B.
|
| 560.809 | Mission Director Status Report - 14-20 May 1993 | CXDOCS::J_BUTLER | E pur, si muove... | Mon May 24 1993 13:44 | 113 |
| Article 3783 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/21/93
Message-ID: <21MAY199320195679@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Fri, 21 May 1993 20:19:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 96
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
May 14 - 20, 1993
SPACECRAFT
1. On May 17, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer
(MAG) instruments. Preliminary analysis indicates the data was received
properly.
2. On May 17, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
3. During the period from May 19 to May 21, a navigation cycle was performed.
This navigation cycle is providing near-continuous acquisition of two-way
doppler and ranging data during four consecutive passes of the spacecraft over
DSS-63 (Madrid 70 meter antenna), DSS-14 (Goldstone 70 meter antenna), DSS-43
(Canberra 70 meter antenna), and then back to DSS-63.
4. On May 19, in preparation for repositioning the Radio Relay Antenna (RRA),
real-time commands were sent to turn the Two-Way Noncoherent (TWNC) on for the
activity. Commands were then sent to update the variable telemetry packets.
Commands were then sent to slew the RRA from about 18.5 degrees from stow to
approximately 5 degrees from stow. The slew executed nominally. Preliminary
analysis indicates the RRA is between 5.5 and 7.0 degrees from stow. After
completion of the slew, real-time commands were sent to reconfigure back to the
original spacecraft configuration. Commands were also sent to restore a
System Fault Protection (SFP) table to its pre-RRA potentiometer calibration
activity state.
5. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19 DN
(4.3 volts). The DC measurement reads 150 DN (17.7 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
6. The Spacecraft status as of May 20, 1993, is as follows:
a) System Power Margin - 72 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 24 degrees
off-sun (lagging) and 3 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 240 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-2 (Earth-Jupiter #2) Final Profile Design was approved by the
Project on May 20, 1993. This sequence covers spacecraft activities from
July 6, 1993 to August 27, 1993 and includes the IDA optical navigation
images and the IDA approach Trajectory Correction Maneuvers (TCMs) Nos. 20
and 21.
TRAJECTORY
As of noon Thursday, May 20, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 245,899,200 km (1.64 AU)
Distance from Sun 323,869,100 km (2.17 AU)
Heliocentric Speed 83,400 km per hour
Distance from Jupiter 492,670,100 km
Round Trip Light Time 27 minutes, 26 seconds
SPECIAL TOPIC
1. As of May 20, 1993, a total of 70361 real-time commands have been
transmitted to Galileo since Launch. Of these, 65250 were initiated in the
sequence design process and 5111 initiated in the real-time command process.
In the past week, 100 real time commands were transmitted; 98 were initiated
in the sequence design process and 2 initiated in the real-time command
process. Major command activities included commands to reset the command loss
timer, turn the TWNC on and off, reposition the RRA, and update a SFP table.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never laugh at anyone's
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | dreams.
|_____|/ |_|/ |_____|/ |
|
| 560.810 | Galileo Update -- 05/24/93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon May 24 1993 21:53 | 33 |
| Article: 3793
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/24/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Mon, 24 May 1993 18:04:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 24, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-63 (Madrid 70 meter antenna) on Saturday. No tracking was
scheduled on Sunday
Today, May 24, 1993, a scan platform over-travel test is scheduled.
Cruise science memory readouts and an USO (Ultra Stable Oscillator) test is
also scheduled. Tracking is scheduled over DSS-63.
Tomorrow, memory readout of scan platform over-travel test data is
scheduled. Tracking is again scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never laugh at anyone's
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | dreams.
|_____|/ |_|/ |_____|/ |
|
| 560.811 | Galileo Update -- 05/25/93 | CXDOCS::J_BUTLER | E pur, si muove... | Wed May 26 1993 17:12 | 42 |
| Article 3799 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!pa.dec.com!decwrl!elroy.jpl.nasa.gov!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/25/93
Message-ID: <25MAY199317270507@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Tue, 25 May 1993 17:27:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 23
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 25, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, a scan platform over-travel test was performed, as planned.
Cruise science memory readouts and an USO (Ultra Stable Oscillator) test were
also scheduled. Tracking was scheduled over DSS-63 (Madrid 70 meter antenna).
Today, May 25, 1993, memory readouts of the scan platform over-travel
test is scheduled. Tracking is scheduled over DSS-63.
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never laugh at anyone's
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | dreams.
|_____|/ |_|/ |_____|/ |
|
| 560.812 | Galileo Update -- 05/26/93 | CXDOCS::J_BUTLER | E pur, si muove... | Thu May 27 1993 14:29 | 44 |
| Article 3811 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/26/93
Message-ID: <26MAY199322083052@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Wed, 26 May 1993 22:08:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 25
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
May 26, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, memory readouts of the scan platform over-travel test data
was performed, as planned. Tracking is scheduled over DSS-63 (Madrid 70
meter antenna).
Today, May 26, 1993, no spacecraft activity or tracking is scheduled.
Tomorrow, cruise science memory readouts, routine RPM (Retro-Propulsion
Module) 10-Newton thruster flushing maintenance activity and a EPD (Energetic
Particle Detector) motor maintenance activity are scheduled. Tracking is
scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never laugh at anyone's
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | dreams.
|_____|/ |_|/ |_____|/ |
|
| 560.813 | Mission Director Status Report - 21-27 May 1993 | CXDOCS::J_BUTLER | E pur, si muove... | Wed Jun 02 1993 21:36 | 136 |
| Article: 3821
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 05/28/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Fri, 28 May 1993 21:53:00 GMT
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
May 21 - 27, 1993
SPACECRAFT
1. On May 21, a cruise science Memory Readout (MRO) was performed for the
Magnetometer (MAG) instrument. Preliminary analysis indicates the data was
received properly.
2. On May 24, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
3. On May 24, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Dust Detector (DDS), and Magnetometer
(MAG) instruments. Preliminary analysis indicates the data was received
properly.
4. On May 24, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect gravitational red shift experiment
data; long term trend analysis is continuing.
5. On May 24, a scan platform overtravel test was performed to collect Scan
Actuator Subassembly (SAS) friction data between 153 degrees and 209.6 degrees.
The test was performed nominally and the data was received without incident.
Analysis of the data is in progress.
6. On May 27, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV) and Magnetometer (MAG) instruments.
Preliminary analysis indicates the data was received properly.
7. On May 27, a routine sun vector update was performed. This sun vector is
valid through August 14, 1993.
8. On May 27, an Energetic Particle Detector (EPD) motor maintenance exercise
was performed which stepped the motor through its eight operating positions
and then returned to the normal position (Sector 4). The motor maintenance
exercise was successfully verified by Memory Readout (MRO).
9. On May 27, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed; all 12 thrusters were flushed
during the activity. Thruster performance throughout the activity was normal.
10. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 151 DN (17.8 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
11. The Spacecraft status as of May 27, 1993, is as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 26 degrees
off-sun (lagging) and 1 degree off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 183 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-3 (Earth-Jupiter #3) Cruise Plan was approved by the Project on
May 26, 1993. This sequence covers spacecraft activity from August 27, 1993
to September 27, 1993, and includes IDA closest approach and early return of
some high priority IDA science observations.
GDS (Ground Data Systems):
1. Galileo participated in a MOSO System Test for MGDS V18.1 Command on
May 20, using DSS-43 (Canberra 70 meter antenna). The test was only
partially successful due to a configuration problem with the GCF (Ground
Communications Facility) and the MOSO test string. The configuration problem
was resolved and the Ulysses portion of the test was conducted with the
station. Due to lack of test time, Galileo used the SIM CPA (Command
Processor Assembly) and was able to translate, interact with the MOSO PDB,
transmit to the SIM CPA, and radiate a command file. The test also
demonstrated the new DTV displays for Command V18.1. The next MOSO System
Test is scheduled for May 27, with DSS-42 (Canberra 34 meter antenna).
2. The April System Engineers Monthly Report(SEMR)/Ground System Development
Office (GSDO) MMR was conducted Thursday, May 27. A review of current Project
and Institutional (DSN and MOSO) system status was conducted. On-going cruise
development plus the GSDO Phase 1 and 2 delivery schedules, past months
accomplishments and potential problem areas were discussed. No significant
schedule changes or problems were reported.
TRAJECTORY
As of noon Thursday, May 27, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 266,373,500 km (1.78 AU)
Distance from Sun 332,836,400 km (2.23 AU)
Heliocentric Speed 81,600 km per hour
Distance from Jupiter 483,737,200 km
Round Trip Light Time 29 minutes, 44 seconds
SPECIAL TOPIC
1. As of May 27, 1993, a total of 70362 real-time commands have been
transmitted to Galileo since Launch. Of these, 65251 were initiated in the
sequence design process and 5111 initiated in the real-time command process.
In the past week, one real time command was transmitted; one was initiated in
the sequence design process and none initiated in the real-time command
process. Major command activities included a command to reset the command
loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never laugh at anyone's
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | dreams.
|_____|/ |_|/ |_____|/ |
|
| 560.814 | Galileo Update -- 06/01/93 | TINCUP::J_BUTLER | E pur, si muove... | Thu Jun 03 1993 14:36 | 43 |
| Article 3890 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 06/01/93
Message-ID: <2JUN199300094061@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Wed, 2 Jun 1993 00:09:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 24
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 1, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, a cruise science memory readout was performed, as planned.
was performed, as planned. Tracking was scheduled over DSS-63 (Madrid 70
meter antenna).
Today, June 1, 1993, cruise science memory readouts are scheduled.
Tracking is again scheduled over DSS-63.
Tomorrow, AACS (Attitude and Articulation Control Subsystem) calibration
data collection is scheduled. Tracking is again scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.815 | More on the HGA | CXDOCS::J_BUTLER | E pur, si muove... | Thu Jun 03 1993 22:23 | 76 |
|
{an interesting exchange on the HGA situation}
{I deleted some of the repetitious remarks to save space}
{ jb }
Article 63727 of sci.space:
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!caen!nigel.msen.com!sdd.hp.com!elroy.jpl.nasa.gov!kelvin.jpl.nasa.gov!baalke
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space
Subject: Re: Galileo's HGA?
Date: 27 May 1993 03:13 UT
Organization: Jet Propulsion Laboratory
Lines: 21
Distribution: world
Message-ID: <27MAY199303132491@kelvin.jpl.nasa.gov>
References: <1u0fi3INN613@lynx.unm.edu> <C7no6I.63E@zoo.toronto.edu>
NNTP-Posting-Host: kelvin.jpl.nasa.gov
News-Software: VAX/VMS VNEWS 1.41
In article <C7no6I.63E@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes...
>In article <1u0fi3INN613@lynx.unm.edu> lyons@us17501.mdc.com writes:
>>What's the status of the high gain antenna?
>
>They've given up on it as hopeless.
At the present time, the Galileo mission is being planned using the Low Gain
Antenna. Attempts to open the High Gain Antenna (HGA) have not been abandoned,
and will continue though not as aggressively as in the past. The HGA is
partially open, and a High Gain uplink test was performed a couple of months
ago to characterize the HGA. The results of this test were, shall we
say, very interesting. A downlink test to follow up on this is scheduled for
next month. The project is commited to using the Low Gain for the Ida
encounter, which is only three months away.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Never laugh at anyone's
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | dreams.
|_____|/ |_|/ |_____|/ |
Article 63749 of sci.space:
From: cshotton@oac.hsc.uth.tmc.edu (Chuck Shotton)
Newsgroups: sci.space
Subject: Re: Galileo's HGA?
Followup-To: sci.space
Date: 27 May 1993 12:15:14 GMT
{repetitious material deleted --jb}
What does "very interesting" mean? Were they able to transfer data? I would
have thought a downlink test would have been more valuable to perform
first, since it would give an idea if any useable bandwidth was available
for science data return, etc. Was there some fear of cranking up
transmitters on a partially deployed antenna?
Article 63758 of sci.space:
From: jfw@ksr.com (John F. Woods)
Newsgroups: sci.space
Subject: Re: Galileo's HGA?
Date: 27 May 93 10:36:57 EDT
{repetitious material deleted -- jb}
Antennas have a property called "reciprocity"; they function exactly as well
receiving as transmitting. Therefore, they could certainly obtain some
characterization of the antenna by having it receive. Since Galileo's
receivers are probably not as good as those on the ground, it would, indeed,
be a less accurate test than transmitting, but they probably did fear damaging
the transmitter with an antenna whose impedance could be any random value.
If "very interesting" means something like "hey, it looks like it has a
noticable major lobe in a useful direction (rather than pointing at a solar
panel, say), and probably is open enough that it isn't too far off the design
impedance", then they may figure it is safe and useful to use the transmitter
to gain a more accurate characterization. Let's all keep our fingers crossed.
|
| 560.816 | Galileo Update -- 06/02/93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jun 04 1993 14:34 | 42 |
| Article 3896 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 06/02/93
Message-ID: <2JUN199317340283@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Wed, 2 Jun 1993 17:34:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 23
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 2, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, cruise science memory readouts were performed, as planned.
Tracking was scheduled over DSS-63 (Madrid 70 meter antenna).
Today, June 2, 1993, AACS (Attitude and Articulation Control Subsystem)
calibration data collection is scheduled. Tracking is scheduled over DSS-63.
Tomorrow, AACS calibration data collection is scheduled to continue.
Tracking is again scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.817 | Galileo Update -- 06/03/93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Jun 07 1993 14:51 | 43 |
| Article 3902 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 06/03/93
Message-ID: <3JUN199320202800@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Thu, 3 Jun 1993 20:20:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 24
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 3, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, AACS (Attitude and Articulation Control Subsystem) calibration
data collection was performed, as scheduled. Tracking was scheduled over
DSS-63 (Madrid 70 meter antenna).
Today, June 3, 1993, the AACS calibration data collection is continuing.
Tracking is again scheduled over DSS-63.
Tomorrow, cruise science memory readouts are scheduled. Tracking is
scheduled over DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.818 | Mission Director Status Rpt -- 28 May-03 Jun '93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Jun 07 1993 14:54 | 125 |
| Article 3904 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!nntpd.lkg.dec.com!news.crl.dec.com!deccrl!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update #2 - 06/03/93
Message-ID: <4JUN199300193730@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Organization: Jet Propulsion Laboratory
Date: Fri, 4 Jun 1993 00:19:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 106
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
May 28 - June 3, 1993
SPACECRAFT
1. On May 31, cruise science Memory Readouts (MRO) were performed for the
Magnetometer (MAG) instrument. Preliminary analysis indicates the data was
received properly.
2. On June 1, at the beginning of the DSS-63 (Madrid 70 meter antenna) pass,
the CDU (Command Data Unit) lock count had unexpectedly increased 2 DN from
its previous value the day before. This change apparently occurred between
the DSS-63 end of track on May 31 and the DSS-63 beginning of track on June 1.
3. On June 1, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
4. On June 1, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV) and Dust Detector (DDS) instruments.
Preliminary analysis indicates the data was received properly.
5. On June 2 and 3, Attitude and Articulation Control Subsystem (AACS)
calibration data was collected on the spin detector, gyros, wobble, spin
bearing assembly drag, and accelerometers.
6. On June 3, a Delayed Action Command (DAC) was transmitted which will turn
ranging on Friday, June 4, 1993. This command was sent to support checkout of
new ground hardware and software modifications at DSS-14 (Goldstone 70 meter
antenna).
7. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19 DN
(4.3 volts). The DC measurement reads 143 DN (16.8 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
8. The Spacecraft status as of June 3, 1993, is as follows:
a) System Power Margin - 70 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 28 degrees
off-sun (lagging) and 2 degree off-earth (lagging)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 260 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The High Gain Antenna (HGA) downlink test mini-sequence was approved by
the Project on June 3, 1993. This mini-sequence covers spacecraft activities
from June 22 to June 25, 1993.
GDS (Ground Data Systems):
1. Galileo participated in a successful MOSO System Test of MGDS V18.1
Command on May 27, using DSS-42 (Canberra 34 meter antenna). Galileo was
able to translate, interact with the MOSO PDB, transmit to the CPA (Command
Processor Assembly), and radiate command files. Monitor 5-9 data was
displayed and appeared correct. Monitor 5-15 data were not tested; the
DSN (Deep Space Network) NOCC (Network Operations Control Center) upgrade to
support the Galileo interface is scheduled for June 7. The MOSO Functional
Area and System Test Reviews (FATR/STR) for MGDS Command V18.1 is scheduled
for June 15, 1993.
TRAJECTORY
As of noon Thursday, June 3, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 287,221,300 km (1.92 AU)
Distance from Sun 341,692,100 km (2.29 AU)
Heliocentric Speed 80,000 km per hour
Distance from Jupiter 475,188,300 km
Round Trip Light Time 32 minutes, 2 seconds
SPECIAL TOPIC
1. As of June 3, 1993, a total of 70364 real-time commands have been
transmitted to Galileo since Launch. Of these, 65252 were initiated in the
sequence design process and 5112 initiated in the real-time command process.
In the past week, two real time commands were transmitted; one was initiated
in the sequence design process and one initiated in the real-time command
process. Major command activities included commands to reset the command loss
timer and to turn ranging on.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.819 | This is stupidity! | VERGA::KLAES | Quo vadimus? | Tue Jun 08 1993 14:47 | 33 |
| Newsgroups: sci.space.news
>From: davem@ee.ubc.ca (Dave Michelson)
Subject: Summary: Galileo budget to be cut....
Originator: yee@atlas.arc.nasa.gov
Organization: University of BC, Electrical Engineering
Date: Tue, 8 Jun 1993 10:46:46 GMT
The Long Arm of NASA Beancounters
---------------------------------
(summarized from "Science" 260, p 1227, 28 May 1993)
NASA has requested that managers slash an additional $20 million from
Galileo's scientific program due to shortfalls in the 1994 NASA budget.
(Managers had already trimmed $60 million from Galileo's budget through 1998
with the expectation that would be sufficient.)
Galileo programs that might be dropped include:
* a study of the magnetic field associated with Jupiter and its moons
* remote sensing studies of Jupiter's atmosphere in UV
* "retooling" of Galileo's transmission equipment to compensate for
the loss of the HGA
The proposed cuts stem from a new NASA policy that more money should be
spent on new projects and less on operating old ones.
The move has been compared to "killing your children to get pregnant again"
by an unnamed NASA official.
|
| 560.820 | Future Historian: "Think of What Might Have Been..." | CXDOCS::J_BUTLER | E pur, si muove... | Tue Jun 08 1993 17:58 | 19 |
| <sigh>
"The proposed cuts stem from a new NASA policy that more money should
be spent on new projects and less on operating old ones."
Great. THAT'S the ticket! Soon we'll just have "fire and forget"
missions.
This is like a farmer who plants his crop, then saves money by not
fertilizing or watering so he can buy more seed next year!
(That reminds me of something my father said (He worked for Hercules,
Inc. on the Polaris and Poseidon contracts) "The best thing that
ever happened to the US Space program was Sputnik!")
Regards,
John B.
|
| 560.821 | | SKYLAB::FISHER | Violence is the last refuge of the incompetent | Tue Jun 08 1993 20:36 | 5 |
| I've already fired off a letter to V.P. Gore about this.
VICE.PRESIDENT@WHITEHOUSE.GOV gets it there.
Burns
|
| 560.822 | | TROOA::BALDOCK | Chris Baldock | Tue Jun 08 1993 22:16 | 6 |
|
Why don't they just cut back on the part of the project that will
return images. i.e. The loss of the HGA is already forcing them
to do this, but don't tell them that. They may just buy it. ;-)
Chris
|
| 560.823 | | AUSSIE::GARSON | nouveau pauvre | Wed Jun 09 1993 03:41 | 17 |
| re .?
> "The proposed cuts stem from a new NASA policy that more money should
> be spent on new projects and less on operating old ones."
Wouldn't it make more sense, if you *have* to cut, to cut or cancel or
postpone new or future projects?
Something can go wrong anytime in the challenging environment of space
so the fact that Galileo has survived for three years now, has
negotiated all of its gravity assists and the bugs (HGA, bus imbalance)
are at least known about, should mean that it is worth supporting to
maximise the return. Moving money to a new unknown project (that itself
may in the end not even get off the launch pad due to further future
cuts) just seems crazy to me. [Hence I would really like to see a fully
funded further cycle for Magellan. It's up there. It's working. Let's
get the most out of it.]
|
| 560.824 | Galileo Update -- 06/04/93 | CXDOCS::J_BUTLER | E pur, si muove... | Wed Jun 09 1993 14:33 | 44 |
| Article 3906 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 06/04/93
Message-ID: <4JUN199317394852@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
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Date: Fri, 4 Jun 1993 17:39:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 25
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 4, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, AACS (Attitude and Articulation Control Subsystem)
calibration data collection was performed, as planned. Tracking was
scheduled over DSS-63 (Madrid 70 meter antenna).
Today, June 4, 1993, cruise science memory readouts are scheduled.
Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna).
Over the weekend, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-63 on Saturday. No tracking is scheduled on Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.825 | Galileo Update -- 06/07/93 | CXDOCS::J_BUTLER | E pur, si muove... | Thu Jun 10 1993 14:34 | 47 |
| Article 3926 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 06/07/93
Message-ID: <7JUN199320551196@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
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Date: Mon, 7 Jun 1993 20:55:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 28
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 7, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. However,
tracking was scheduled over DSS-63 (Madrid 70 meter antenna) on Saturday.
Today, June 7, 1993, cruise science memory readouts are scheduled, along
with a USO (Ultra Stable Oscillator) test. Real-time commands are scheduled
to update the acquisition sensor parameters. A tape recorder conditioning
activity is also scheduled. Delta DOR (Differential One-way Range) passes are
scheduled over DSS-14 (Goldstone 70 meter antenna) and DSS-63, and DSS-14 and
DSS-43 (Canberra 70 meter antenna). Tracking is scheduled over DSS-63,
DSS-14 and DSS-43.
Tomorrow, a HIC (Heavy Ion Counter) memory readout is scheduled.
Tracking is scheduled over DSS-14, DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.826 | Galileo Update -- 06/08/93 | CXDOCS::J_BUTLER | E pur, si muove... | Thu Jun 10 1993 14:35 | 48 |
| Article 3950 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 06/08/93
Message-ID: <8JUN199321381034@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
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Date: Tue, 8 Jun 1993 21:38:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 29
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 8, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, cruise science memory readouts were performed, along
with an USO (Ultra Stable Oscillator) test. Real-time commands were sent
to update the acquisition sensor parameters. A tape recorder conditioning
activity was also performed. Delta DOR (Differential One-way Range) passes
were performed over DSS-14 (Goldstone 70 meter antenna) and DSS-63 (Madrid
70 meter antenna), and DSS-14 and DSS-43 (Canberra 70 meter antenna).
Tracking was scheduled over DSS-63, DSS-14 and DSS-43.
Today, June 8, 1993, a HIC (Heavy Ion Counter) engineering memory readout
is being performed. Tracking is scheduled over DSS-14, DSS-43 and DSS-63.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.827 | Mission Director Status Report - 4-10 June 1993 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Jun 14 1993 14:12 | 126 |
| Article 3972 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 06/11/93
Message-ID: <11JUN199318400788@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Fri, 11 Jun 1993 18:40:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 107
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
June 4 - 10, 1993
SPACECRAFT
1. On June 4, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV) and Magnetometer (MAG) instruments.
Preliminary analysis indicates the data was received properly.
2. On June 7, cruise science Memory Readouts (MROs) were performed for the
Magnetometer (MAG) and Dust Detector (DDS) instruments. Analysis indicates
the data was received properly.
3. On June 7, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect gravitational red shift experiment
data; long term trend analysis is continuing.
4. On June 7, real-time commands were sent to update an Acquisition Sensor
(AS) parameter for a solar distance greater than 2.0 AU. The AS parameters
are updated periodically due to the changing spacecraft to sun distance.
5. On June 7, a periodic Data Management Subsystem (DMS) conditioning activity
was performed. The tape recorder was rewound and positioned to a different
location. This activity executed nominally.
6. On June 7, delta Differenced One-way Range (DOR) passes were performed
over DSS-14/63 (Goldstone/Madrid 70 meter antennas) and DSS-14/43
(Goldstone/Canberra 70 meter antennas). Initial results indicate that both
delta DOR passes were successful.
7. On June 8, a Heavy Ion Counter (HIC) engineering Memory Readout (MRO) was
performed. HIC engineering data was received and data analysis is in progress.
8. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 19 DN
(4.3 volts). The DC measurement reads 144 DN (16.9 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
9. The Spacecraft status as of June 10 1993, is as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 29 degrees
off-sun (lagging) and 4 degree off-earth (lagging)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 185 hours
GDS (Ground Data Systems):
1. A Galileo MVT (Mission Verification Test) was performed on June 8, 1993,
from 13:20:00 to 21:00:00 GMT, using DSS-15 (Goldstone 34 meter antenna).
The purpose of the test was to evaluate the new Type A Telemetry Group
Controller (TGC) and Telemetry Channel AssemblyUs (TCA) ability to support
Galileo. This test exercised telemetry, and monitor for Galileo on both
MCCC (MTS) and the V18.1 MGDS. At 10 bps metering problem was discovered in
the new TCA which caused the MCCC (MTS) system to lose data due to time-outs.
This problem was seen on the MGDS system, but the GIF (Gatway Interface
between GCF (Ground Communications Facility) and SFOC(Space Flight Operations
Center)) was able to compensate for the problem by extending its
time-out values. The problem was also seen at 40 bps (coded and uncoded), but
did not cause the MCCC (MTS) system to time-out (however the MTS was running
marginally, and close to time-out values). Due to this metering problem, the
MVT was declared unsuccessful. At the present time the DSN (Deep Space
Network) is working on a fix (or work around) for this anomaly. The Type A
TGC/TCA was expected to go into SOAK by June 18, 1993.
TRAJECTORY
As of noon Thursday, June 10, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 308,352,700 km (2.06 AU)
Distance from Sun 350,433,700 km (2.34 AU)
Heliocentric Speed 78,400 km per hour
Distance from Jupiter 467,001,100 km
Round Trip Light Time 34 minutes, 24 seconds
SPECIAL TOPIC
1. As of June 10, 1993, a total of 70382 real-time commands have been
transmitted to Galileo since Launch. Of these, 65270 were initiated in the
sequence design process and 5112 initiated in the real-time command process.
In the past week, 18 real time commands were transmitted; 18 were initiated in
the sequence design process and none initiated in the real-time command
process. Major command activities included commands to update an Acquisition
Sensor (AS) parameter.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.828 | June 14 status report: Spacecraft emergency | SKYLAB::FISHER | Violence is the last refuge of the incompetent | Mon Jun 14 1993 17:40 | 28 |
|
GALILEO STATUS REPORT
Spacecraft Emergency
June 14, 1993
A spaceraft emergency was declared by the Galileo project on June 11,
1993 at 2040Z. DSS-63 (Madrid 70 meter antenna) did not lock up on the
telemetry from the spacecraft on the nominal subcarrier of 22.5 khz after
acquistion of the signal at 17:45Z. The subcarrier was found to be the
high subcarrier of 360 khz, indicating the spacercraft was in safe mode.
The reason for the safemode is unknown. The project commanded the spacecraft
back to low subcarrier at 2141Z with Traveling Wave Non-Coherent mode on.
The station then locked up on the telemetry and the project was able process
the data from the spacecraft.
The Galileo emergency was lifted at 2110Z on June 12. DSS-63 acquired
the signal at 13:25 for support activities necessary to condition, restart
and clear the CDS-A (Command Data Subsystem) string and obtain memory
readouts which will confirm the spacecraft's health and status. The spacecraft
looks to be in nominal condition and telemetry was being processed from the
A side of the spacecraft. DSS-63 was released from support at 2115Z.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.829 | Galileo Update (#2) -- 06/14/93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Jun 14 1993 19:31 | 44 |
| Article 3984 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update #2 - 06/14/93
Message-ID: <14JUN199317315776@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Keywords: Galileo, JPL
Sender: digester@news.arc.nasa.gov
Nntp-Posting-Host: kelvin.jpl.nasa.gov
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Date: Mon, 14 Jun 1993 17:31:00 GMT
Approved: sci-space-news@ames.arc.nasa.gov
Lines: 25
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 14, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, real-time commands were sent to reconfigure the
spacecraft after a safing event was detected on Friday. Tracking was
scheduled over DSS-63 (Madrid 70 meter antenna).
Today, June 14, 1993, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-63.
Tomorrow, real-time commands are scheduled to uplink the CDS (Command
Data Subsystem) 80 byte memory readout software patch. Tracking is scheduled
over DSS-63 and DSS-14 (Goldstone 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The tuatara, a lizard-like
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | reptile from New Zealand,
|_____|/ |_|/ |_____|/ | has three eyes.
|
| 560.830 | Galileo Update -- 06/15/93 | CXDOCS::J_BUTLER | E pur, si muove... | Thu Jun 17 1993 13:59 | 31 |
| Article 4005 of sci.space.news:
Newsgroups: sci.space.news
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 15, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-63 (Madrid 70 meter antenna).
Today, June 15, 1993 real-time commands are scheduled to uplink the CDS
(Command Data Subsystem) 80 byte memory readout software patch. Tracking is
scheduled over DSS-63 and DSS-14 (Goldstone 70 meter antenna).
Tomorrow, real-time commands are scheduled to update system fault
protection response, uplink the CDS IM4 imaging software patch, and turn the
tweak off and S-band ranging on. Tracking is scheduled over DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't outlive your money.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.831 | Galileo Update -- 06/16/93 | CXDOCS::J_BUTLER | E pur, si muove... | Thu Jun 17 1993 14:00 | 35 |
| Article 4006 of sci.space.news:
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 16, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, real-time commands were sent to uplink the CDS (Command Data
Subsystem) 80 byte memory readout software load, as planned. Tracking is
scheduled over DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone 70
meter antenna).
Today, June 16, 1993, real-time commands are scheduled to modify the
system fault protection downlink response, uplink the CDS IM4 imaging
software patch, and turn the tweak off and S-band ranging on. A mini-sequence
is also scheduled for uplink to execute a thruster flushing maintenance
activity and a SITURN tomorrow. Tracking is scheduled over DSS-63 and DSS-14.
Tomorrow, a thruster flushing maintenance activity and SITURN are
scheduled. A mini-sequence is also scheduled to be uplinked which will
reconfigure the spaceraft to its pre-safing state in preparation for the
beginning of the EJ-2 (Earth-Jupter #2) sequence. Tracking is scheduled over
DSS-63, DSS-14 and DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't outlive your money.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.832 | Mission Director Status Report 11-17 Jun 1993 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Jun 21 1993 13:53 | 164 |
| Article 4034 of sci.space.news:
Newsgroups: sci.space.news
Path: nntpd2.cxo.dec.com!pa.dec.com!decwrl!ames!dont-send-mail-to-path-lines
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 06/18/93
Message-ID: <18JUN199316185598@kelvin.jpl.nasa.gov>
To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
News-Software: VAX/VMS VNEWS 1.41
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
June 11 - 17, 1993
SPACECRAFT
1. At the beginning of the DSS-63 (Madrid 70 meter antenna) track on
June 11, the DSN (Deep Space Network) was unable to lock up on the spacecraft
low frequency subcarrier. After approximately 30 minutes of troubleshooting,
the DSN locked up on the high frequency subcarrier with no telemetry being
processed. These responses indicated the spacecraft had entered safing
and the Command and Data Subsystem (CDS) string RAS was down. Real-time
commands were sent to reconfigure downlink telemetry to the CDS RBS string.
Subsequently, telemetry lock was achieved and the data confirmed that the
spacecraft had entered safing and the CDS RAS string was down. Subsequent
real-time commands were sent to reset the CDS telemetry indicator, thus
confirming the expectations that the RAS string down was caused by a spurious
transient bus reset signal similar to that observed on March 26, May 2 and
July 19, 1991. Analysis of spacecraft telemetry data indicated that the
anomaly occurred at about 1000 PDT on June 10 during a non-track period.
On June 12, real-time commands were sent to reconfigure the CDS RAS
string for recovery and restart. All commands were properly received and
executed by the spacecraft and the CDS RAS string was brought back "on-line"
and fully redundant CDS operation was restored within 28 hours of anomaly
detection on the ground. Near the end of the recovery and restart activity,
the CDS RAS string was selected as the prime string as it was prior to the
anomaly.
2. On June 14, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
3. On June 15, real-time commands were sent to patch and load new code
modules for the 80 byte Memory Readout (MRO) capability. Commands were first
sent to the CDS RAS string, updates verified by checksums and then 80 byte
MROs performed on the changes. Then the same procedure was performed on the
CDS RBS string. Both strings were "on-line" during the activity with the CDS
RAS string selected as prime.
4. On June 16, real-time commands were sent to modify the System Fault
Protection (SFP) downlink response for low data rates (10 bps and 40 bps).
Specifically, the SFP downlink response was changed from selecting the high
frequency subcarrier and a S-Band 10 bps modulation index of 19 to selecting
the low frequency subcarrier and a S-band 10 bps modulation index of 29.
5. On June 16, real-time commands were sent to patch the CDS flight software
in order to correct the IM4 imaging timing race condition. Specifically, the
modification delays the CDS transfer of SSI (Solid State Imaging camera) data
to the DMS (tape recorder) by an additional 3.85 msec. This change was
implemented to support data return for the IDA encounter (closest approach
will occur on August 28, 1993).
6. On June 16, real-time commands were sent to turn the Two-Way Non-Coherent
(TWNC) off and the S-band ranging on. These commands will allow the
collection of ranging data for navigation purposes.
7. On June 16, a mini-sequence was uplinked to the spacecraft which included
a periodic RPM (Retro-Propulsion Module) 10-Newton thruster flushing
maintenance activity and SITURN. This mini-sequence was required as a result
of the spacecraft safing event on June 10 which terminated the on-board
sequence EJ-1 (Earth-Jupiter #1) .
8. On June 17, a periodic RPM 10-N thruster flushing maintenance activity
was performed. At approximately 1140 PDT during the RPM flushing activity,
spacecraft telemetry lock was lost while the DSN had good SNR. Initial anomaly
signature indicates a CDS RAS string bus reset occurred. The spacecraft is
in a safe state. Troubleshooting, fault isolation, and recovery are in
progress.
[ The spacecraft went into safe mode at approximately 1141 PDT for an
unknown reason while tracking with DSS-63 (Madrid 70 meter antenna).
The 40 bps coded telemetry was unusable through the end of track at
1441 PDT. When DSS-14 (Goldstone 70 meter antenna) was brough online
at 1541 PDT, the spacecraft was commanded to turn telemetry on from CDS-B.
The signal was acquired from the spacecraft and 40 bps coded telemetry was
in-lock at 1638 PDT with a SNR of 27 db.
Ron Baalke
]
9. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 17 DN
(3.9 volts). The DC measurement reads 147 DN (17.3 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
10. The Spacecraft status as of June 17 1993, is as follows:
a) System Power Margin - 61 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 31 degrees
off-sun (lagging) and 6 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EPD, SSI, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 239 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-2 (Earth-Jupiter #2) Preliminary sequence and command generation
package was approved by the Project on June 11, 1993. This sequence covers
spacecraft activities from July 6, 1993 to August 27, 1993 and includes the
IDA optical navigation images and the IDA approach Trajectory Correction
Maneuvers (TCMs).
2. The High Gain Antenna (HGA) downlink test mini-sequence was approved for
transmission by the Project on June 17, 1993. This mini-sequence covers
spacecraft activities from June 22 to June 25, 1993.
TRAJECTORY
As of noon Thursday, June 17, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 329,684,200 km (2.21 AU)
Distance from Sun 359,059,800 km (2.40 AU)
Heliocentric Speed 76,900 km per hour
Distance from Jupiter 459,155,000 km
Round Trip Light Time 36 minutes, 46 seconds
SPECIAL TOPIC
1. As of June 17, 1993, a total of 70984 real-time commands have been
transmitted to Galileo since Launch. Of these, 65523 were initiated in the
sequence design process and 5461 initiated in the real-time command process.
In the past week, 602 real time commands were transmitted; 253 were initiated
in the sequence design process and 349 initiated in the real-time command
process. Major command activities included commands to bring the CDS RAS
string up after a spurious bus reset signal, reset the command loss timer,
patch and load new code modules for the 80 byte MRO, modify the SFP downlink
response, patch the CDS flight software for the IM4 timing race condition,
turn the TWNC off and S-band ranging on, and uplink a mini-sequence to perform
thruster flushing and a SITURN.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't outlive your money.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.833 | Galileo Update -- 06/21/93 | CXDOCS::J_BUTLER | E pur, si muove... | Tue Jun 22 1993 14:34 | 29 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 21, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, a thruster flushing maintenance activity and SITURN
were executed, as planned. Tracking was scheduled over DSS-63 (Madrid 70
meter antenna) and DSS-14 (Goldstone 70 meter antenna) on Saturday, and DSS-14
on Sunday.
Today, June 21, 1993, the HGA (High Gain Antenna) X-band downlink test
mini-sequence is being uplinked. Delayed Action Commands are also scheduled to
turn the PCT (Photometric Calibration Target) heater on and off, and turn the
UVS (Ultraviolet Spectrometer) supplemental heater on. Tracking is scheduled
over DSS-63.
Tomorrow, the HGA X-band downlink test is scheduled to begin. Tracking
is scheduled over DSS-63, DSS-14 and DSS-43 (Canberra 70 meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't outlive your money.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.834 | | SKYLAB::FISHER | Violence is the last refuge of the incompetent | Tue Jun 22 1993 16:00 | 8 |
| I wish they would not be so close-mouthed about this HGA test (and the previous
HGA uplink test)!
Does anyone know whether the HGA was normally to be communicating using X-band?
I'm wondering if this test is trying to use the HGA in a different way (e.g. if
it is not opened would it have a better impedance match with a higher frequency).
Burns
|
| 560.835 | Galileo Update -- 06/22/93 | CXDOCS::J_BUTLER | E pur, si muove... | Tue Jun 22 1993 21:38 | 29 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 22, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, the HGA (High Gain Antenna) X-band downlink test mini-sequence
was uplinked, as planned. Delayed Action Commands were also sent to turn the
PCT (Photometric Calibration Target) heater on and off, and turn the UVS
(Ultraviolet Spectrometer) supplemental heater on. Tracking was scheduled
over DSS-63 (Madrid 70 meter antenna).
Today, June 22, 1993 , the HGA X-band downlink test is in progress.
Tracking is scheduled over DSS-63, DSS-14 (Goldstone 70 meter antenna) and
DSS-43 (Canberra 70 meter antenna).
Tomorrow, the HGA X-band downlink test is schedule to continue. Tracking
is scheduled over DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't outlive your money.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.836 | Some HGA Information... | CXDOCS::J_BUTLER | E pur, si muove... | Tue Jun 22 1993 22:12 | 25 |
| From: n4hy@wahoo.ccr-p.ida.org (Bob McGwier)
From the USENET:
Newsgroups: sci.space
Subject: Re: Galileo Update - 06/21/93 (Antenna)
Date: 22 Jun 93 11:41:33
Organization: IDA Center for Communications Research
In-reply-to: wa2ise@netcom.com's message of Tue, 22 Jun 1993 03:49:30 GMT
They ran a RECEIVE test and it showed that it was deployed enough to have
at least a lobe in its antenna pattern with usable gain. This is to be
tested in the reverse direction to see if the antenna produces usable gain
without harming the transmitter along the same lobe. If so, then the data
rate can be increased, and more useful science done. The antenna still has
not deployed COMPLETELY.
Bob
--
------------------------------------------------------------------------------
Robert W. McGwier | n4hy@ccr-p.ida.org
Center for Communications Research | Interests: amateur radio, astronomy,golf
Princeton, N.J. 08520 | Asst Scoutmaster Troop 5700, Hightstown
|
| 560.837 | Galileo Update -- 06/23/93 | CXDOCS::J_BUTLER | E pur, si muove... | Wed Jun 23 1993 19:35 | 24 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
June 23, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, the HGA (High Gain Antenna) X-band downlink test proceeded,
as planned. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna),
DSS-14 (Goldstone 70 meter antenna) and DSS-43 (Canberra 70 meter antenna).
Today, June 23, 1993, the HGA X-band downlink test is scheduled to
continue. Tracking is scheduled over DSS-43 and DSS-63.
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't outlive your money.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.838 | Mission Director Status Report - 18-24 Jun 93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Jun 28 1993 14:35 | 163 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
June 18 - 24, 1993
SPACECRAFT
1. On June 17, after the spacecraft entered safing and the Command and Data
Subsystem (CDS) String A went down about 1140AM PDT, real-time commands were
sent to reconfigure the CDS A string for recovery and restart. All commands
were properly received and executed by the spacecraft and the CDS A string was
brought back on-line and fully redundant CDS operation was restored within 12
hours of anomaly detection on the ground. Additional commanding to configure
the spacecraft for the High Gain Antenna (HGA) X-band downlink test and start
of the EJ-2 (Earth-Jupiter #2) sequence were being planned. This anomaly was
caused by a spurious transient bus reset signal similar to that observed on
March 26, May 2, and July 19, 1991; and more recently the anomaly on June 11,
1993.
2. On June 18, the remainder of the commands for reconfiguring the CDS A
string were sent which included Memory Readouts (MROs) for the Dust Detector
(DDS), Plasma Subsystem (PLS), Energetic Particle Detector (EPD), and Solid
State Imaging (SSI) instruments. All of the EPD MRO and a portion of the SSI
MRO data was not received due to a lightning strike at DSS-63 (Madrid 70 meter
antenna). Real-time commands were then sent to turn the SSI instrument off
and its replacement heater on. Commands were also sent to turn the Two-Way
Non-Coherent (TWNC) off and S-band ranging on for navigation purposes.
Real-time commands were then sent to switch the high rate telemetry to the
CDS B string and the low rate telemetry to the CDS A string. This change was
made to prevent the disruption of spacecraft telemetry in the event of another
spurious transient CDS bus A reset.
3. On June 19, a mini-sequence was uplinked and subsequently executed a
periodic RPM (Retro-Propulsion Module) 10-Newton thruster flushing maintenance
activity and a SITURN. This mini-sequence was required as a result of the
spacecraft safing event on June 10 which terminated the EJ-1 sequence and the
spacecraft safing event on June 17 which terminated the recovery flushing and
SITURN mini-sequence. Eight of the twelve thrusters were flushed; the
S-thrusters were flushed on June 17 prior to the safing event. Thruster
performance throughout the activity was nominal. The spacecraft then executed
about an 8-degree unbalanced SITURN for the purpose of attitude maintenance.
The Z-thrusters were used for the SITURN activity.
4. On June 21, the High Gain Antenna (HGA) X-band downlink test mini-sequence
was uplinked to the spacecraft without incident. This mini-sequence reset
the command loss timer to 72 hours, its planned value during this test.
Delayed Action Commands (DACs) were also sent to turn the Photometric
Calibration Target (PCT) heater on and off and turn the Ultraviolet
Spectrometer (UVS) supplemental heater on for power management.
5. On June 22 and 23, a NO-OP command was sent to reset the command loss
timer to 72 hours, its planned value for the HGA downlink test. Additionally,
the HGA downlink mini-sequence set the command loss timer back to 264 hours
at the end of the test on June 23. Another NO-OP was then sent to reset the
command loss timer to 264 hours.
6. On June 22, as part of the HGA downlink test, the X-band transmitter was
turned on in the low power mode with the S-Band transmitter in high power
using the Low Gain Antenna (LGA). Sixteen HGA corrections were performed
which stepped the spacecraft pointing in 0.25 degree increments from 0 degrees
to 4 degrees off the minus Z axis. All telemetry indications were per
predicts. DSS-63 locked up intermittently on the X-band carrier during the
test. Data analysis is in process.
7. On June 23, the HGA downlink test continued. Three SITURNS were performed
to map 20 degrees off the minus Z axis. The first SITURN went from 4 degrees
to 20 degrees off the minus Z axis, the second went from 20 degrees through
the Earth to 20 degrees on the other side, and the third went from 20 degrees
to 1.75 degrees off the minus Z axis (which was the initial attitude prior to
the test). The test was performed nominally and all telemetry indications were
per predicts. DSS-63 locked up intermittently on the X-band carrier during
the test. Data analysis is in progress.
8. On June 23, real-time commands were sent to turn the Heavy Ion Counter
(HIC) high voltage on in order to protect the detectors. These commands are
required because after the safing events on June 10 and 17, the instrument was
reconfigured with the HIC on and the high voltage off.
9. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 149 DN (17.5 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
10. The Spacecraft status as of June 24, 1993, is as follows:
a) System Power Margin - 76 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 25 degrees
off-sun (lagging) and 2 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EPD, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 236 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-2 final sequence and command generation package was reviewed by the
Project on June 22, 1993. Approval is pending generation of the final
SEQTRAN products. This sequence covers spacecraft activities from July 6, 1993
to August 27, 1993 and includes the IDA optical navigation images and the IDA
approach Trajectory Correction Maneuvers (TCMs).
GDS (Ground Data Systems):
1. A Galileo Ground Data System (GDS) test of MGDS V18.1 Command (CMD) was
conducted on June 18 using DSS-45 (Canberra 34 meter antenna). The test went
well and no problems were seen commanding with V18.1 CMD. This test also
validated the flow of monitor 5-15 data through the MGDS. Limited success
with the monitor 5-15 displays were achieved during the test due to a monitor
decom map problem. This problem was resolved after the conclusion of the test
and the monitor data was displayed using V18.1 Data Monitor and Display (DMD)
capabilities. Even though all functional test objectives were achieved, the
test was not conducted using the actual Galileo operational LAN and hardware
(H/W) configuration due to the unavailability of MOSO provided H/W. The
new H/W is in the procurement cycle and is expected to be installed and
configured for Galileo by August 1. The extent of GDS retesting following
this installation is TBD. The next GDS test of V18.1 CMD is scheduled for
June 27 with DSS-12 (Goldstone 34 meter antenna).
TRAJECTORY
As of noon Thursday, June 24, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 351,116,100 km (2.35 AU)
Distance from Sun 367,569,400 km (2.46 AU)
Heliocentric Speed 75,400 km per hour
Distance from Jupiter 451,630,500 km
Round Trip Light Time 39 minutes, 8 seconds
SPECIAL TOPIC
1. As of June 24, 1993, a total of 71294 real-time commands have been
transmitted to Galileo since Launch. Of these, 65530 were initiated in the
sequence design process and 5764 initiated in the real-time command process.
In the past week, 310 real time commands were transmitted; 7 were initiated
in the sequence design process and 303 initiated in the real-time command
process. Major command activities included commands to bring the CDS A string
up after a spurious bus reset signal, turn the TWNC off and S-band ranging on,
switch the high rate telemetry to the CDS B string and the low rate telemetry
to the CDS A string, uplink a mini-sequence to perform thruster flushing and
a SITURN, uplink the HGA X-band downlink test mini-sequence, turn the PCT
heater on and off, turn the UVS supplemental heater on, turn the HIC high
voltage on, and reset the command loss timer.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't outlive your money.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.839 | Mission Director Status Report - 25 Jun-01 Jul 93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 02 1993 14:19 | 106 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
June 25 - July 1, 1993
SPACECRAFT
1. On June 25, as part of the High Gain Antenna (HGA) X-band downlink test,
Memory Readouts (MROs) of the attitude control subsystem high rate data were
performed to collect position data at one and one-third second intervals for
the SITURNS executed on June 23. The data was received without incident and
detailed analysis is in progress.
2. On June 28, a mini-sequence was uplinked and subsequently executed which
configured the spacecraft for the start of the EJ-2 (Earth-Jupiter #2)
sequence. This mini-sequence was required due to the spacecraft safing events
which occurred on June 10 and June 17, 1993.
3. On June 30, the EJ-2 sequence memory load was uplinked to the spacecraft
without incident. This sequence covers spacecraft activities from July 6, 1993
to August 27, 1993 and includes the IDA optical navigation images and the IDA
approach Trajectory Correction Maneuvers (TCMs).
4. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 153 DN (18.0 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
5. The Spacecraft status as of July 1, 1993, is as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 26 degrees
off-sun (lagging) and 3 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 236 hours
Significant Spacecraft ISAs: None
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-2 sequence memory load was approved for transmission by the Project
on June 29, 1993. This sequence covers spacecraft activities from July 6, 1993
to August 27, 1993.
2. The EJ-3 final profile design package was reviewed by the Project on
June 30, 1993. Approval is pending NIMS/PPR (Near Infrared Mapping
Spectrometer/Photopolarimeter Radiometer) team review of constraint checking
products. This sequence covers spacecraft activities from August 27 to
September 27, 1993 and includes the IDA closest approach on August 28 and the
initial return of science data.
GDS (Ground Data Systems):
1. A Galileo Ground Data System (GDS) test of MGDS V18.1 Command (CMD) was
conducted on June 27, using DSS-12 (Goldstone 34 meter antenna). The test
went well and no problems were seen commanding with V18.1 CMD. This test
also validated the flow of monitor 5-15 data through the MGDS. Even though
all functional test objectives were achieved, the test was not conducted using
the actual Galileo operational LAN and hardware (H/W) configuration due to the
unavailability of MOSO provided H/W. A MOSO proposed solution to this H/W
configuration problem was accepted by the Projects on June 30. The next GDS
test of V18.1 CMD, which will be performed in the operational configuration,
is scheduled for July 8, with DSS-45 (Canberra 34 meter antenna).
TRAJECTORY
As of noon Thursday, July 1, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 372,540,700 km (2.49 AU)
Distance from Sun 375,962,200 km (2.51 AU)
Heliocentric Speed 74,000 km per hour
Distance from Jupiter 444,409,100 km
Round Trip Light Time 41 minutes, 30 seconds.
SPECIAL TOPIC
1. As of July 1, 1993, a total of 71294 real-time commands have been
transmitted to Galileo since Launch. Of these, 65530 were initiated in the
sequence design process and 5764 initiated in the real-time command process.
In the past week, no real time commands were transmitted. Major command
activities included commands to uplink a mini-sequence to configure the
spacecraft for the EJ-2 sequence, and uplink of the EJ-2 sequence memory load.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't outlive your money.
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 |
|_____|/ |_|/ |_____|/ |
|
| 560.840 | Galileo Update -- 07/06/93 | CXDOCS::J_BUTLER | E pur, si muove... | Wed Jul 07 1993 12:43 | 27 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 6, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the 4th of July holiday weekend, no spacecraft activity was
scheduled. Tracking was scheduled over DSS-63 (Madrid 70 meter antenna) on
Friday, Saturday and Sunday. No tracking was scheduled on Monday.
Today, July 6, 1993, the EJ-2 (Earth-Jupiter #2) sequence is scheduled
to begin. Tracking is scheduled over DSS-63.
Tomorrow, a routine 10-Newton thruster flushing maintenance activity
and SITURN are scheduled. Science memory readouts are also scheduled.
Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There is no such thing as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a "temporary" tax increase.
|_____|/ |_|/ |_____|/ |
|
| 560.841 | Galileo Update -- 07/07/93 | CXDOCS::J_BUTLER | E pur, si muove... | Wed Jul 07 1993 20:09 | 27 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 7, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, the EJ-2 (Earth-Jupiter #2) sequence began. Tracking was
scheduled over DSS-63 (Madrid 70 meter antenna).
Today, July 7, 1993, a routine 10-Newton thruster flushing maintenance
activity and SITURN are being performed. Science memory readouts were also
scheduled. Tracking is scheduled over DSS-63.
Tomorrow, real-time commands are scheduled to modify system fault
protection parameters. A USO (Ultra Stable Oscillator) test is also scheduled.
Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There is no such thing as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a "temporary" tax increase.
|_____|/ |_|/ |_____|/ |
|
| 560.842 | Galileo Update -- 07/08/93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 09 1993 15:13 | 29 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 8, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, a routine 10-Newton thruster flushing maintenance activity
and SITURN was performed, as planned. Science memory readouts were also
scheduled. Tracking was scheduled over DSS-63 (Madrid 70 meter antenna).
Today, July 8, 1993, real-time commands are scheduled to modify system
fault protection parameters. A USO (Ultra Stable Oscillator) test is also
scheduled. Tracking is scheduled over DSS-63.
Tomorrow, the SSI (Solid State Imaging camera) is scheduled to be turned
on for the upcoming optical navigation activities. Collection of acquisition
sensor data is also scheduled. Tracking is scheduled over DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There is no such thing as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a "temporary" tax increase.
|_____|/ |_|/ |_____|/ |
|
| 560.843 | Mission Director Status Report - 2-8 July '93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 09 1993 15:15 | 96 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 2 - 8, 1993
SPACECRAFT
1. On July 6, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
2. On July 7, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed; all 12 thrusters were flushed
during the activity. Thruster flushing throughout the activity was nominal.
3. On July 7, the spacecraft, under stored sequence control, performed about
a 12-degree unbalanced SITURN for the purpose of attitude maintenance. The Z
thrusters were used during the activity.
4. On July 7, cruise science Memory Readouts (MROs) were performed for the
Extreme Ultraviolet Spectrometer (EUV), Magnetometer (MAG), and Dust Detector
(DDS) instruments. Preliminary analysis indicates the data was received
properly.
5. On July 8, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect gravitational red shift experiment
data; long term trend analysis is continuing.
6. On July 8, real-time commands were sent to modify System Fault Protection
(SFP) parameters and to turn the bay C/D shunt heater on. Specifically, the
SFP parameters were modified to turn the bay C/D shunt heater on and the
Photometric Calibration Target (PCT) heater No. 2 off in the event of sequence
termination.
7. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 156 DN (18.4 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
8. The Spacecraft status as of July 8, 1993, is as follows:
a) System Power Margin - 58 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 15 degrees
off-sun (lagging) and 7 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 259 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-3 (Earth-Jupiter #3) final profile design package was approved by
the Project on July 6, 1993. This sequence covers spacecraft activities
from August 27 to September 27, 1993 and includes the IDA closest approach
on August 28 and the initial return of science data.
TRAJECTORY
As of noon Thursday, July 8, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 393,869,200 km (2.63 AU)
Distance from Sun 384,238,100 km (2.57 AU)
Heliocentric Speed 72,700 km per hour
Distance from Jupiter 437,473,800 km
Round Trip Light Time 43 minutes, 54 seconds
SPECIAL TOPIC
1. As of July 8, 1993, a total of 71303 real-time commands have been
transmitted to Galileo since Launch. Of these, 65531 were initiated in the
sequence design process and 5772 initiated in the real-time command process.
In the past week, 9 real time commands were transmitted; 1 was initiated in
the sequence design and 8 were initiated in the real-time command process.
Major command activities included commands to reset the command loss timer and
modify system fault protection parameters.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There is no such thing as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a "temporary" tax increase.
|_____|/ |_|/ |_____|/ |
|
| 560.844 | Galileo Update -- 07/09/93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 09 1993 19:20 | 28 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 9, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, real-time commands were sent to modify system fault protection
parameters. A USO (Ultra Stable Oscillator) test was also performed, as
planned. Tracking was scheduled over DSS-63 (Madrid 70 meter antenna).
Today, July 9, 1993, the SSI (Solid State Imaging camera) is scheduled
to be turned on for the upcoming optical navigation activities. Collection of
acquisition sensor data is also scheduled. Tracking is scheduled over DSS-63.
Over the weekend, cruise science memory readouts are scheduled on
Sunday. No spacecraft activity is scheduled on Saturday. Tracking is
scheduled over DSS-14 (Goldstone 70 meter antenna) on Saturday and DSS-63 on
Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There is no such thing as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a "temporary" tax increase.
|_____|/ |_|/ |_____|/ |
|
| 560.845 | Galileo Update -- 07/12/93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Jul 12 1993 21:12 | 23 |
|
GALILEO STATUS REPORT
July 12, 1993
On July 10, 1993 after DSS-14 (Goldstone 70 meter antenna) had
acquired the signal from the Galileo spacecraft at 2105Z, it was discovered
that the spacecraft had entered safemode. It was determined that the
CDS-A (Command and Data Subsystem A) had failed and the spacecraft had
swapped to CDS-B. The cause of this event was a transient signal as in the
previous safing events. The spaceraft is being reconfigured to the state
required to perform the EJ-2 (Earth-Jupiter #2) sequence. The current
spacecraft configuration as of July 12, 1993 1400Z: LGA-1 (Low Gain Antenna),
22.5 KHZ telemetry subcarrier, TWNC (Traveling Wave Non Coherent) on, and
ranging channel off.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There is no such thing as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a "temporary" tax increase.
|_____|/ |_|/ |_____|/ |
|
| 560.846 | Galileo Update #2 -- 07/12/93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Jul 12 1993 21:13 | 29 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 12, 1993
The Galileo Spacecraft appears to have entered safing with the CDS-A
(Command and Data Subsystem A) string down.
Over the weekend, at the beginning of the DSS-14 (Goldstone 70 meter
antenna) track on Saturday, telemetry had indicated that the spacecraft had
entered safing and the CDS-A string had gone down. Commands were sent to
reconfigure the CDS-A string for recovery and restart. Full redundant CDS
operations were restored by Sunday afternoon. Tracking was scheduled on
DSS-14 on Saturday and DSS-63 (Madrid 70 meter antenna) on Sunday.
Today, July 12, 1993, at the beginning of the DSS-63 track, data appears
to indicate that the spacecraft has again has entered safing and the CDS-A
string has gone down. In this particular configuration, telemetry data cannot
be processed. Commands are currently being planned to reconfigure the CDS-A
string for recovery and restart. Tracking is scheduled over DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There is no such thing as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a "temporary" tax increase.
|_____|/ |_|/ |_____|/ |
|
| 560.847 | Galileo Update -- 07/13/93 | CXDOCS::J_BUTLER | E pur, si muove... | Wed Jul 14 1993 21:10 | 27 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 13, 1993
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, at the beginning of the DSS-63 (Madrid 70 meter antenna) track,
data indicated that the spacecraft had again entered safing and the CDS-A
(Command and Data Subsystem A) string had gone down. Commands were sent to
reconfigure the CDS-A string for recovery and restart. Full redundant CDS
operation was restored Monday evening. Tracking was scheduled over DSS-63
and DSS-14 (Goldstone 70 meter antenna).
Today, July 13, 1993, no spacecraft activity is scheduled. Tracking is
scheduled over DSS-14.
Tomorrow, no spacecraft activity or tracking is scheduled.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There is no such thing as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a "temporary" tax increase.
|_____|/ |_|/ |_____|/ |
|
| 560.848 | Galileo Update -- 07/15/93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 16 1993 13:40 | 25 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 15, 1993
The Galileo Spacecraft is operating in the dual-spin mode and is
transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity or tracking was scheduled.
Today, July 15, 1993, a navigation cycle is scheduled to begin.
Tracking is scheduled over DSS-63 (Madrid 70 meter antenna), DSS-14
(Goldstone 70 meter antenna) and DSS-43 (Canberra 70 meter antenna).
Tomorrow, real-time commands are scheduled to update AACS (Attitude
and Articulation Control Subsystem) parameters and to perform memory readouts
for the SSI (Solid State Imaging camera). Tracking is scheduled over
DSS-63 and DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | There is no such thing as
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | a "temporary" tax increase.
|_____|/ |_|/ |_____|/ |
|
| 560.849 | Mission Director Status Report - 7-15 Jul 1993 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 16 1993 16:59 | 136 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 9 - 15, 1993
SPACECRAFT
1. On July 9, the Solid State Imaging (SSI) camera was powered on in
preparation for the optical navigation activities scheduled to begin the
following week. The instrument memories were readout and verified to be
nominal.
2. On July 9, Acquisition Sensor (AS) data was collected and is being analyzed
for a possible AS parameter update scheduled for July 16.
3. At the beginning of the DSS-14 (Goldstone 70 meter antenna) track on
July 10, numerous telemetry channels were in alarm. Further analysis of the
telemetry channels indicated the spacecraft had entered safing and the Command
and Data Subsystem (CDS) A string was down. Real-time commands were sent to
reset the CDS telemetry indicator which confirmed the expectations that the A
string down was caused by a spurious transient bus reset signal similar to
those observed on March 26, 1991; May 2, 1991; July 19, 1991; June 11, 1993;
and June 17, 1993. Analysis of spacecraft telemetry data indicated that the
anomaly occurred at about 1316 PDT on July 10 during a non-track period.
Real-time commands were then sent to reconfigure the CDS A string for
recovery and restart. All commands were properly received and executed by
the spacecraft and the CDS A string was brought back on-line and fully
redundant CDS operation was restored at approximately 1200 PDT on July 11,
1993. Real-time commands were also sent to turn the Heavy Ion Counter
(HIC) high voltage on to protect its detectors.
4. On July 12, at the beginning of the DSS-63 (Madrid 70 meter antenna) pass,
the DSN (Deep Space Network) locked up on the low frequency subcarrier but no
telemetry was being processed. These responses indicated the spacecraft had
again entered safing and the CDS String A was down. Real-time commands were
sent to reconfigure downlink telemetry to the CDS B string. Subsequently,
telemetry lock was achieved and the data confirmed that the spacecraft had
entered safing and the CDS A string was down. Subsequent real-time commands
were sent to reset the CDS telemetry indicator, thus confirming the A string
down was caused by another spurious transient bus reset signal. Analysis of
spacecraft telemetry data indicated that the anomaly occurred at about 1837 PDT
on July 11 during a non-track period.
Real-time commands were then sent to reconfigure the CDS A string for
recovery and restart. All commands were properly received and executed by the
spacecraft and the CDS A string was brought back on-line and fully redundant
CDS operation was restored at approximately 2000 PDT on July 12, 1993.
Real-time commands were also sent to turn the Heavy Ion Counter (HIC) high
voltage on to protect its detectors. The high rate telemetry was switched to
the CDS B string and the low rate telemetry to the CDS A string. This change
will prevent the disruption of spacecraft telemetry in the event of another
spurious transient CDS Bus A reset. Real-time commands were sent to turn the
Two-Way Non-Coherent (TWNC) off and Delayed Action Commands (DACs) were sent
to turn S-band ranging on and off on July 15.
5. On July 15, a navigation cycle began and will complete on July 16 providing
near-continuous acquisition of two-way doppler and ranging during four
consecutive passes of the spacecraft over DSS-63, DSS-14, DSS-43 (Canberra
70 meter antenna), and then back to DSS-63.
6. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 159 DN (18.8 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
7. The Spacecraft status as of July 15, 1993, is as follows:
a) System Power Margin - 59 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 17 degrees
off-sun (lagging) and 5 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EPD, SSI, HIC and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 195 hours
GDS (Ground Data Systems):
1. Galileo Ground Data System (GDS) tests of MGDS V18.1 Command (CMD) were
conducted on July 8 and July 14 with DSS-45 and DSS-42 (Canberra 34 meter
antennas), respectively. The tests went well with V18.1 CMD being exercised
thoroughly. During the test with DSS-45 a problem with the CPA (Command
Processor Assembly) was observed. The CPA was reloaded and the rest of the
test proceeded without incident. These tests also validated the flow of
monitor 5-15 data through the MGDS. Even though all functional test objectives
were achieved, the tests were not conducted using the actual Galileo
operational PBD and CMD central hardware (H/W) configuration. The July 14
test was the last scheduled GDS test prior to the August 1 start of MCCC/MGDS
Command parallel operations, but due to the lack of a complete flight
configuration additional GDS tests are being scheduled. The first of these
additional GDS tests are scheduled for July 19 with DSS-42.
TRAJECTORY
As of noon Thursday, July 15, 1993, the Galileo Spacecraft trajectory
status was as follows:
Distance from Earth 415,018,900 km (2.78 AU)
Distance from Sun 392,397,500 km (2.62 AU)
Heliocentric Speed 71,400 km per hour
Distance from Jupiter 430,808,300 km
Round Trip Light Time 46 minutes, 14 seconds
SPECIAL TOPIC
1. As of July 15, 1993, a total of 71892 real-time commands have been
transmitted to Galileo since Launch. Of these, 65531 were initiated in the
sequence design process and 6361 initiated in the real-time command process.
In the past week, 589 real time commands were transmitted of which all were
initiated in the real-time command process. Major command activities included
commands to bring the CDS A string up after spurious bus reset signals, turn
the HIC high voltage on, switch the high rate telemetry to the CDS B string
and the low rate telemetry to the CDS A string, and turn the TWNC off and
the S-band ranging on and off.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Common sense is not very
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | common.
|_____|/ |_|/ |_____|/ |
|
| 560.850 | Galileo Update -- 07/19/93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Jul 19 1993 20:27 | 30 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 19, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and is
transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna), DSS-63 (Madrid 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna) on Saturday, and over
DSS-14 on Sunday.
Today, July 19, 1993, a science reconfiguration mini-sequence is scheduled
to be uplinked. Real-time commands are scheduled to turn on the PWS (Plasma
Wave) calibration tones, and switch the tape recorder back to track 2.
DAC's (Delayed Action Commands) are also scheduled to turn on the PCT
(Photometric Calibration Target) heater #1 to off and heater #2 to on.
Tracking is scheduled over DSS-14.
Tomorrow, the science reconfiguration mini-sequence is scheduled to
execute. Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Common sense is not very
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | common.
|_____|/ |_|/ |_____|/ |
|
| 560.851 | Galileo Update -- 07/21/93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 23 1993 01:30 | 29 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 21, 1993
IDA -38 Days
The Galileo Spacecraft is operating in the all-spin mode and is
transmitting coded telemetry at 40 bps (bits/second).
Yesterday, the science reconfiguration mini-sequence was executed, as
planned. Tracking was scheduled over DSS-14 (Goldstone 70 meter antenna).
Today, July 21, 1993, the EJ-2 (Earth-Jupiter #2) sequence memory load
is scheduled to be uplinked. DAC's (Delayed Action Commands) are scheduled to
return to the dual-spin mode for the optical navigation #2 shuttering
activities. Real-time commands are scheduled to perform a memory readout for
the SSI (Solid State Imaging) camera. Tracking is scheduled over DSS-63
(Madrid 70 meter antenna) and DSS-14.
Tomorrow, optical navigation #2 is scheduled to be shuttered.
Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Common sense is not very
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | common.
|_____|/ |_|/ |_____|/ |
|
| 560.852 | Galileo Update -- 07/22/93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 23 1993 01:30 | 30 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 22, 1993
IDA -37 Days
The Galileo Spacecraft is operating in the all-spin mode and is
transmitting coded telemetry at 40 bps (bits/second).
Yesterday, the EJ-2 (Earth-Jupiter #2) sequence memory load was uplinked,
as planned. DAC's (Delayed Action Commands) were sent to reconfigure the
spacecraft to the dual-spin mode just prior to the optical navigation #2
activities, and back to all-spin after the shutter activity completes.
Real-time commands were sent to perform a memory readout for the SSI (Solid
State Imaging) camera. Tracking was scheduled over DSS-63 (Madrid 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, July 22, 1993, optical navigation #2 is scheduled to be shuttered,
and memory readouts of the data will begin. Tracking is scheduled over DSS-14.
Tomorrow, memory readouts of optical navigation #2 data is scheduled to
continue. Tracking is scheduled over DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Common sense is not very
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | common.
|_____|/ |_|/ |_____|/ |
|
| 560.853 | Mission Director Status Report - 15-22 Jul 1993 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 23 1993 16:46 | 150 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 16 - 22, 1993
SPACECRAFT
1. On July 16, real-time commands were sent to update the attitude control
subsystem flight software parameters for the acquisition sensor. These
parameters were updated using the acquisition sensor data gathered on July 9.
Additionally, the spin rate and pointing deadbands were returned to their
EJ-2 (Earth-Jupiter) sequence values. The Spacecraft safing changes the
spin rate and pointing deadbands. Before sequence controlled operations can be
resumed the values must be consistent.
2. On July 16, real-time commands were sent to change the spacecraft spin
configuration from the dual-spin to the all-spin mode. This action was taken
to reduce the likelihood of another transient bus reset signal since all
related information to date suggests that the spacecraft in the dual-spin
mode is more susceptible to this anomaly.
3. On July 19, in preparation for the EJ-2 prime sequence memory load, a
science instrument mini-sequence was uplinked to reconfigure the spacecraft to
its appropriate state which had changed as a result of the Command and Data
Subsystem (CDS) bus reset anomalies on July 10 and 11. The mini-sequence was
uplinked and executed on the spacecraft without incident.
4. On July 19, Delayed Action Commands (DACs) were sent to turn the
Photometric Calibration Target (PCT) heater No. 1 off and PCT heater No. 2 on.
This heater configuration is required to preclude PCT contamination when
thrusters are fired in the EJ-2 prime sequence and to maintain the planned
power margin for Retro-Propulsion Module (RPM) tank temperature and pressure
control.
5. On July 19, real-time commands were sent to turn on a calibration tone for
the Plasma Wave Subsystem (PWS) B-antenna. This will provide B-antenna
performance information which will be used in the upcoming Jupiter sequence
planning.
6. On July 19, real-time commands were sent to select Track 2 for the DMS
(tape recorder). This configured the tape recorder for the start of the EJ-2
prime sequence and the upcoming optical navigation No. 2 activities.
7. On July 21, Delayed Action Commands (DACs) were sent to reconfigure the
spacecraft from the all-spin to the dual-spin mode on July 22 just prior to
the optical navigation No. 2 activities and then back to all-spin after the
shuttering activity had completed. The time in the dual-spin mode was
minimized to reduce the likelihood of another CDS bus reset anomaly.
8. On July 21, the EJ-2 prime sequence memory load was uplinked to the
spacecraft without incident. This sequence covers spacecraft activities from
July 22, 1993 to August 27, 1993 and includes IDA optical navigation images
No. 2 through 5 and the IDA approach Trajectory Correction Maneuvers (TCMs).
Additionally, Memory Readouts (MROs) were performed for the Solid State
Imaging (SSI) camera to verify its status prior to the start of optical
navigation activities. The MROs indicated the SSI was operating nominally.
9. On July 22, the EJ-2 prime sequence memory load went active and optical
navigation No. 2 activities are in progress at the writing of this report.
Memory Readouts (MROs) of optical navigation No. 2 data are scheduled
through July 26, 1993.
10. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 153 DN (18.0 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
11. The Spacecraft status as of July 22, 1993, is as follows:
a) System Power Margin - 56 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89rpm/Star Scanner
d) Spacecraft Attitude is approximately 18 degrees
off-sun (lagging) and 3 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, SSI, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 235 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-2 prime sequence memory load was approved by the Project on
July 20, 1993. The use of prime is a naming convention which distinguishes
the original EJ-2 sequence from the EJ-2 prime sequence. Changes to the
EJ-2 sequence only eliminated events which had been previously accomplished
or which had been lost because of safing. This sequence covers spacecraft
activities from July 22, 1993 to August 27, 1993.
GDS (Ground Data Systems):
1. Galileo Ground Data System (GDS) tests of MGDS V18.1 Command (CMD) were
conducted on July 19 and July 21 with DSS-42 (Canberra 34 meter antenna).
The first test failed due to a MGDS System Monitor and Control (SMC) disk
fragmentation error. The test on July 21 went well with V18.1 CMD being
exercised thoroughly. This test also validated the flow of MON 5-9 and
MON 5-15 data through the MGDS. The test outcome was only partially
successful due to a LAN problem at the end of the test period. Analysis of
the LAN problem is underway and a Failure Report will be generated. All
functional test objectives were achieved and the test was conducted using the
actual Galileo operational software and hardware configuration. The next
GDS test is scheduled for Saturday, July 24 with DSS-15 (Goldstone 34 meter
antenna).
TRAJECTORY
As of noon Thursday, July 22, 1993, the Galileo Spacecraft trajectory
status is as follows:
Distance from Earth 435,892,200 km (2.92 AU)
Distance from Sun 400,440,900 km (2.68 AU)
Heliocentric Speed 70,100 km per hour
Distance from Jupiter 424,397,300 km
Round Trip Light Time 48 minutes, 34 seconds
SPECIAL TOPIC
1. As of July 22, 1993, a total of 71927 real-time commands have been
transmitted to Galileo since Launch. Of these, 65546 were initiated in the
sequence design process and 6381 initiated in the real-time command process.
In the past week, 35 real time commands were transmitted; 15 were initiated in
the sequence design process and 20 initiated in the real-time command process.
Major command activities included commands to update the attitude control
subsystem flight software parameters, reset the spin rate and pointing
deadbands, switch from dual-spin to all-spin, uplink a science instrument
mini-sequence, turn the PCT No. 1 heater off and PCT No. 2 heater on, turn
the PWS calibration tone on, select the tape recorder Track 2, reconfigure
from all-spin to dual-spin and back to all-spin, uplink the EJ-2 prime
sequence memory load, and perform an SSI MRO.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Common sense is not very
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | common.
|_____|/ |_|/ |_____|/ |
|
| 560.854 | Galileo Update -- 07/23/93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 23 1993 21:33 | 28 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 23, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, optical navigation #2 was shuttered and memory readouts of
the data began, as planned. Tracking was scheduled over DSS-14 (Goldstone
70 meter antenna).
Today, July 23, 1993, memory readouts of optical navigation #2 data
is continuing. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna)
and DSS-14.
Over the weekend, memory readouts of optical navigation #2 data is
scheduled to continue. Tracking is scheduled over DSS-63 and DSS-14
on Saturday, and over DSS-14 on Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Common sense is not very
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | common.
|_____|/ |_|/ |_____|/ |
|
| 560.855 | half way there(?) | AUSSIE::GARSON | nouveau pauvre | Sat Jul 24 1993 06:40 | 7 |
| re .853
Notice that Galileo is now closer to Jupiter than to Earth.
I guess that this is the first time that this is the case. It is not
obvious to me whether this will be the case from now on (probably it
will), although obviously it definitely will be eventually.
|
| 560.856 | Galileo Update -- 07/26/93 | CXDOCS::J_BUTLER | E pur, si muove... | Tue Jul 27 1993 15:01 | 29 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 26, 1993
IDA -43 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, memory readouts of optical navigation #2 data continued,
as planned. Tracking was scheduled over DSS-63 (Madrid 70 meter antenna) and
DSS-14 (Goldstone 70 meter antenna) on Saturday, and over DSS-14 on Sunday.
Today, July 26, 1993, memory readouts of optical navigation #2 data was
completed, as planned. MAG (Magnetometer) and SSI (Solid State Imagining
camera) memory readouts are being performed. DACs (Delayed Action Commands)
are also scheduled to be sent to perform dual to all-spin transition through
August 21, 1993. Tracking is scheduled over DSS-63 and DSS-14.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Common sense is not very
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | common.
|_____|/ |_|/ |_____|/ |
|
| 560.857 | Galileo Update -- 07/28/93 | CXDOCS::J_BUTLER | E pur, si muove... | Fri Jul 30 1993 14:14 | 31 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
July 28, 1993
IDA -31 Days
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, no spacecraft activity was scheduled. Tracking was scheduled
over DSS-14 (Goldstone 70 meter antenna).
Today, July 28, 1993, a routine RPM (Retro-Propulsion Module) thruster
flushing maintenance activity and cruise science memory readouts are scheduled.
The spacecraft will be in the dual-spin mode for approximately 3 hours and
15 minutes for the thruster flushing maintenance activity, and then will return
to the all-spin mode. DACs (Delayed Action Commands) are being sent to turn
ranging on and off. Tracking is scheduled over DSS-63 (Madrid 70 meter
antenna).
Tomorrow, telecommunication tests are scheduled. Memory readouts are
also scheduled for the SSI (Solid State Imaging camera) and MAG (Magnetometer)
instruments. Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Common sense is not very
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | common.
|_____|/ |_|/ |_____|/ |
|
| 560.858 | Mission Director Status Report -- 23-29 Jul 93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Aug 02 1993 19:22 | 140 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 23 - 29, 1993
SPACECRAFT
1. On July 23, cruise science Memory Readouts (MROs) were performed for the
Magnetometer (MAG) and Extreme Ultraviolet Spectrometer (EUV) instrument.
Preliminary analysis indicates the data was received properly.
2. The tape recorder (DMS) playback of optical navigation No. 2 was performed
on July 22, 23, 24, 25 and completed on July 26, 1993 with all image data
retrieved.
3. On July 26 and 29, cruise science Memory Readouts (MROs) were performed
for the Magnetometer (MAG) instrument. Analysis indicates the data was
received properly.
4. On July 26 and 29 Memory Readouts (MROs) were performed for the Solid
State Imaging (SSI) camera. The MRO on July 26 was not received due to a
delayed ground station transmitter on-time which subsequently caused data
dropouts during the SSI MRO. The second SSI MRO indicated the camera was
operating normally.
5. On July 26, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
6. On July 26, Delayed Action Commands (DACs) were sent to reconfigure the
spacecraft from the all-spin to the dual-spin mode for required EJ-2 (Earth-
Jupiter #2) prime sequence activities and then back to all-spin for activities
through August 21, 1993. The time in the dual-spin mode is being minimized
to reduce the likelihood of another CDS (Command and Data Subsystem) bus reset
anomaly.
7. On July 28, a periodic RPM (Retro-Propulsion Module) 10-Newton thruster
flushing maintenance activity was performed; all 12 thrusters were flushed
during the activity. Thruster flushing throughout the activity was nominal.
The spacecraft was in the dual-spin mode for approximately 3 hours and 15
minutes for the thruster flushing maintenance activity and then returned to
the all-spin mode.
8. On July 28, Delayed Action Commands (DACs) were sent to turn ranging on
July 30 and back off August 1 for the purpose of collecting navigation data.
During transmission of the DACs, two Command Detection Unit (CDU) lock change
counts were observed but the commands were not received by the Command and
Data Subsystem (CDS) due to a ground station hardware problem. The DACs were
retransmitted and received by the spacecraft without further incident.
9. On July 28, cruise science Memory Readouts (MROs) were performed for the
Dust Detector (DDS) instrument. Data analysis is in progress.
10. On July 29, a command threshold test and Radio Frequency Subsystem
Automatic Gain Control (RFSAGC) test were performed over DSS-14 (Goldstone
70 meter antenna). Data analysis is in progress. These tests are
periodically performed to provide detailed information relative to the
telecom command hardware integrity.
11. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 155 DN (18.3 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
12. The Spacecraft status as of July 29, 1993, is as follows:
a) System Power Margin - 53 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89rpm/Star Scanner
d) Spacecraft Attitude is approximately 19 degrees
off-sun (lagging) and 2 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, SSI, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 232 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-3 Preliminary Sequence and Command Generation package was approved
by the Project on July 23, 1993. This sequence covers spacecraft activities
from August 27 to September 27, 1993 and includes the IDA closest approach on
August 28 and the initial return of science data.
2. The EJ-4/5/6 Cruise Plan was approved by the Project on July 29, 1993 and
covers spacecraft activities from September 27, 1993 to September 6, 1994.
GDS (Ground Data Systems):
1. Galileo Ground Data System (GDS) test of MGDS V18.1 Command (CMD) was
conducted on July 24 with DSS-15 (Goldstone 34 meter antenna). This was the
fifth GDS test with V18.1 CMD and the second test in the actual Galileo
flight configuration. The central command computer (SMC3) being used by
Galileo failed during the test and the backup computer (SMC4) was brought up
in less than 5 minutes and was used throughout the rest of the test. The
remainder of the test went well with V18.1 CMD being exercised thoroughly.
This test also validated the flow of MON 5-9 and MON 5-15 data through the
MGDS. All functional test objectives were achieved and the test was conducted
using the actual Galileo operational software and hardware configuration.
The next GDS test is scheduled for Thursday, July 29 with DSS-42 (Canberra
34 meter antenna).
TRAJECTORY
As of noon Thursday, July 29, 1993, the Galileo Spacecraft trajectory
status is as follows:
Distance from Earth 456,383,300 km (3.05 AU)
Distance from Sun 408,369,200 km (2.73 AU)
Heliocentric Speed 68,900 km per hour
Distance from Jupiter 418,226,500 km
Round Trip Light Time 50 minutes, 50 seconds
SPECIAL TOPIC
1. As of July 29, 1993, a total of 71945 real-time commands have been
transmitted to Galileo since Launch. Of these, 65547 were initiated in the
sequence design process and 6398 initiated in the real-time command process.
In the past week, 18 real time commands were transmitted; one was initiated in
the sequence design process and 17 initiated in the real-time command process.
Major command activities included commands to reset the command loss timer,
reconfigure from all-spin to dual-spin and back to all-spin, and turn ranging
on and off.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Common sense is not very
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | common.
|_____|/ |_|/ |_____|/ |
|
| 560.859 | Galileo Update -- 08/02/93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Aug 02 1993 22:55 | 32 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 2, 1993
IDA -26 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, DAC's (Delay Action Commands) executed on Sunday which
turned ranging off. Tracking was scheduled over DSS-63 (Madrid 70 meter
antenna) on Sunday. No tracking was scheduled for Saturday.
Today, August 2, 1993, cruise science memory readouts were scheduled
along with the SSI (Solid State Imaging camera) memory readouts. Delta-DOR's
(Differntial One-way Range) passes were also scheduled for DSS-14/DSS-63
(Goldstone/Madrid) and DSS-14/DSS-43 (Goldstone/Canberra). Tracking was
scheduled over DSS-14. At this time, due to Mars Observer problems, the DSS-14
pass has been cancelled, along with the DSS-14/DSS-63 Delta-DOR and the
DSS-14/DSS-43 Delta-DOR. Plans are in the works to try to save the
DSS-14/DSS-43 Delta-DOR.
Tomorrow, a USO (Ultra Stable Oscillator) test is scheduled. Tracking is
scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.860 | Galileo Update -- 08/03/93 | CXDOCS::J_BUTLER | E pur, si muove... | Tue Aug 03 1993 21:34 | 27 |
| Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 3, 1993
IDA -25 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, cruise science memory readouts and a SSI (Solid State Imaging
camera) memory readout were performed on the spacecraft but not recieved on
the ground due loss of DSN (Deep Space Network) station coverage which was
reassigned to the Mars Observer project in support of a spacecraft safing
anomoly. The scheduled Delta-DOR (Differntial One-way Range) passes were
also cancelled.
Today, August 3, 1993, a USO (Ultra Stable Oscillator) test is scheduled.
Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna).
Tomorrow, a 40 bps telemetry performance test is scheduled. Tracking is
scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.861 | Galileo Update -- 08/04/93 | TINCUP::J_BUTLER | E pur, si muove... | Mon Aug 09 1993 14:50 | 27 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 4, 1993
IDA -24 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, a USO (Ultra Stable Oscillator) test was performed, as planned.
Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna).
Today, August 4, 1993, a 40 bps telemetry performance test is scheduled.
Tracking is scheduled over DSS-14.
Tomorrow, DACs (Delayed Action Commands) are scheduled to be sent to
perform an all-spin transition on August 11. A SSI (Solid State Imaging
camera) memory readout and wobble identification are also scheduled.
Tracking is scheduled over DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.862 | Galileo Update -- 08/05/93 | TINCUP::J_BUTLER | E pur, si muove... | Mon Aug 09 1993 14:51 | 30 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 5, 1993
IDA -19 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, a 40 bps telemetry performance test was performed, as planned.
Tracking is scheduled over DSS-14 (Goldstone 70 meter antenna).
Today, August 5, 1993, DACs (Delayed Action Commands) are scheduled to
be sent to perform an all-spin transition on August 11. A SSI (Solid State
Imaging camera) memory readout and wobble identification are also scheduled.
The spacecraft will be in the dual-spin mode for approximately 3 hours and
30 minutes for the wobble identification activity and then will return to
the all-spin mode. Tracking is scheduled over DSS-14.
Tomorrow, a cruise science memory readout is scheduled. Tracking is
scheduled over DSS-43 (Canberra 70 meter antenna) and DSS-63 (Madrid 70 meter
antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.863 | Mission Director Status Report -- 30 Jul - 5 Aug 93 | TINCUP::J_BUTLER | E pur, si muove... | Mon Aug 09 1993 14:53 | 124 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
July 30 - August 5, 1993
SPACECRAFT
1. On August 2, delta Differenced One-Way Range (DOR) passes were scheduled
over DSS-14/63 (Goldstone/Madrid 70 meter antenna) and DSS-14/43 (Goldstone/
Canberra 70 meter antennas). The delta DOR activity was not performed due to
loss of DSN (Deep Space Network) station coverage which was reassigned to the
Mars Observer Project in support of a spacecraft safing anomaly.
2. On August 2 and 5, Memory Readouts were performed for the Solid State
Imaging (SSI) camera. The MRO on August 2 was not received due to loss of DSN
station coverage which was reassigned to the Mars Observer Project as discussed
above. The MRO on August 5 indicated the camera was operating normally.
3. On August 2, cruise science Memory Readouts (MROs) were performed for the
Dust Detector (DDS), Magnetometer (MAG), and Extreme Ultraviolet Spectrometer
(EUV) instruments. The data was not received on the ground due to loss of
DSN station coverage which was reassigned to the Mars Observer Project as
discussed above.
4. On August 3, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase. This command was
originally scheduled on August 2 and was changed when DSN station coverage was
reassigned to the Mars Observer Project as discussed above.
5. On August 3, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect gravitational red shift experiment
data; long term trend analysis is continuing.
6. On August 4, a 40 bps telemetry performance test was conducted. The ground
station transmitters were stepped through a range of power outputs to determine
the effects on the received downlink telemetry signal. Analysis of the data is
in progress.
7. On August 5, Delayed Action Commands (DACs) were sent to transition to
cruise mode after optical navigation No. 3 on August 11, turn the gyros off and
transition to the all-spin mode. The commands were received without incident.
8. On August 5, the spacecraft transitioned to dual-spin mode, gyros were
turned on and the wobble identification activity is in progress at the writing
of this report. The spacecraft is expected to be in the dual-spin mode for
approximately 3 hours 30 minutes to perform the wobble identification
activities.
9. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 156 DN (18.4 volts). These
measurements are consistent with the model developed by the AC/DC special
anomaly team.
10. The Spacecraft status as of August 5, 1993, is as follows:
a) System Power Margin - 38 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.15rpm/Star Scanner
d) Spacecraft Attitude is approximately 20 degrees
off-sun (lagging) and 3 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, SSI, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 260 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-3 (Earth-Jupiter #3) Final Sequence and Command Generation package
was approved by the Project on August 5, 1993. This sequence covers spacecraft
activities from August 27 to September 27, 1993 and includes the IDA closest
approach on August 28 and the initial return of science data.
GDS (Ground Data Systems):
1. The Galileo Readiness Review for MGDS Version 18.1 was conducted on
August 5. The major Galileo support function provided by MGDS Version 18.1 is
the uplink command capability replacing the current MCCC Command System. The
Project concluded that MGDS Version 18.1 was ready to start parallel operations
during which the AMMOS/MGDS Command System will be used for flight support as
much as possible, but the MCCC Command Systems will still be available. At
the end of parallel operations (planned for October 93), assuming no
significant MGDS problems are discovered, the MCCC Command System support will
be decommitted.
TRAJECTORY
As of noon Thursday, August 5, 1993, the Galileo Spacecraft trajectory
status is as follows:
Distance from Earth 476,406,000 km (3.19 AU)
Distance from Sun 416,183,200 km (2.78 AU)
Heliocentric Speed 67,800 km per hour
Distance from Jupiter 412,282,300 km
Round Trip Light Time 53 minutes, 4 seconds
SPECIAL TOPIC
1. As of August 5, 1993, a total of 71950 real-time commands have been
transmitted to Galileo since Launch. Of these, 65548 were initiated in the
sequence design process and 6402 initiated in the real-time command process.
In the past week, 5 real time commands were transmitted; one was initiated in
the sequence design process and 4 initiated in the real-time command process.
Major command activities included commands to reset the command loss timer,
and transition to the all-spin mode.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.864 | Galileo Update -- 08/09/93 | TINCUP::J_BUTLER | E pur, si muove... | Tue Aug 10 1993 13:44 | 30 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 9, 1993
IDA -19 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, no spacecraft activity was scheduled. Tracking was
scheduled over DSS-63 (Madrid 70 meter antenna) on Sunday, and no tracking
was scheduled on Saturday.
Today, August 9, 1993, cruise science memory readouts were scheduled
along with SSI (Solid State Imaging camera) memory readouts. The memory
readouts were not received due to tracking over DSS-63 being delayed due to
Ulysses project investigation of a spacecraft anomaly.
Tomorrow, real-time commands are scheduled to modify telemetry maps in
support of the upcoming optical navigation activities. Tracking is scheduled
over DSS-63, DSS-14 (Goldstone 70 meter antenna) and DSS-43 (Canberra 70
meter antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.865 | Galileo Update -- 08/10/93 | TINCUP::J_BUTLER | E pur, si muove... | Wed Aug 11 1993 15:02 | 31 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 10, 1993
IDA -18 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, cruise science memory readouts were performed along with SSI
(Solid State Imaging camera) memory readouts. The memory readouts were not
received due to tracking over DSS-63 (Madrid 70 meter antenna) being delayed
due to support the Ulysses project investigation of a spacecraft anomaly.
Today, August 10, 1993, real-time commands are scheduled to modify
telemetry maps in support of the upcoming optical navigation activities.
Tracking is scheduled over DSS-63, DSS-14 (Goldstone 70 meter antenna) and
DSS-43 (Canberra 70 meter antenna).
Tomorrow, cruise science memory readouts are scheduled along with SSI
memory readouts. A SITURN is also scheduled. Optical navigation #3 is
scheduled to be shuttered along with a start of a navigation cycle.
Tracking is scheduled over DSS-43, DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.866 | Galileo Update -- 08/12/93 | TINCUP::J_BUTLER | E pur, si muove... | Fri Aug 13 1993 14:34 | 35 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 12, 1993
IDA -16 Days
The Galileo Spacecraft is operating in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second). The CDS-A (Command
& Data Subsystem) string is being recovered from a CDS bus reset signal which
caused the spacecraft to enter safing.
Yesterday, cruise science memory readouts was performed for the MAG
(Magnetometer) instrument. At approximately 3:32 PM PDT, one minute after
transitioning from all-spin to dual-spin mode, a bus reset signal occurred
which caused the spacecraft to enter safing and the A string to go down.
Commands were sent to begin reconfiguration of CDS-A string for recovery and
restart. Tracking was scheduled over DSS-43 (Canberra 70 meter antenna),
DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, August 12, 1993, commands are scheduled to complete the recovery
and restart of CDS-A string. Real-time commands are also scheduled to perform
power reconfigurations. Memorys load are also scheduled to e uplinked to
perform TCM-20 (Trajectory Correction Maneuver #20) and a SITURN. Tracking is
scheduled over DSS-43, DSS-63 and DSS-14.
Tomorrow, the SITURN and TCM-20 are scheduled to execute. Tracking is
scheduled over DSS-43, DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.867 | Mission Director Status Report -- 06-12 Aug 1993 | TINCUP::J_BUTLER | E pur, si muove... | Mon Aug 16 1993 13:59 | 134 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 6 - 12, 1993
SPACECRAFT
1. On August 6 and 11, a cruise science Memory Readout (MRO) was performed
for the Magnetometer (MAG) instrument. Preliminary analysis indicates the
data was received properly.
2. On August 6, at the beginning of the DSS-63 (Madrid 70 meter antenna)
track, the station was having difficulty locking up on the spacecraft downlink
signal. Troubleshooting was initiated to attempt to isolate the problem. At
approximately 7:02 AM PDT, one minor frame of telemetry data was processed
which indicated the spacecraft was operating normally. At approximately
8:45 AM PDT, a steady signal was acquired and telemetry processed after the
station reloaded its antenna pointing predicts. Further analysis of the
telemetry data indicated the spacecraft was operating nominally.
3. On August 9, a Memory Readout (MRO) was performed for the Solid State
Imaging (SSI) camera. The MRO was not received due to loss of DSN (Deep
Space Network) station coverage which was reassigned to the Ulysses Project in
support of a spacecraft anomaly.
4. On August 9, cruise science Memory Readouts (MROs) were performed for the
Dust Detector (DDS) and Magnetometer (MAG) instruments. The data was not
received on the ground due to loss of DSN station coverage which was reassigned
to the Ulysses Project as discussed above.
5. On August 9, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
6. On August 10, real-time commands were sent to modify telemetry Map 3 in
support of the optical navigation playback activities scheduled for August 13
through 15.
7. On August 10, real-time commands were sent to perform a cruise science
Memory Readout (MRO) for the Dust Detector (DDS) instrument. This MRO was
sent to collect the DDS cruise science data originally scheduled on August 9
which was not received as discussed above. Analysis indicates the data was
received properly.
8. On August 11, approximately one minute after the Delayed Action Command
(DAC) executed to transition the spacecraft from the all-spin to the dual-spin
mode in preparation for the scheduled SITURN, telemetry channels indicated the
spacecraft had entered safing and the Command and Data Subsystem (CDS) A string
was down. Real-time commands were sent to reset the CDS telemetry indicator
which confirmed the expectation that the A string down was caused by a
transient bus reset signal. This anomaly occurred at approximately 3:32 PM PDT
on August 11, 1993.
Real-time commands were then sent to reconfigure the CDS A string for
recovery and restart. During the transmission of recovery Package E, a bit
verify error occurred while transmitting Element 34. The Command Processor
Assembly (CPA) at the DSN ground station was reloaded and recovery Package E
retransmitted without further incident. The CDS A string was brought back
on-line and fully redundant CDS operation was restored at approximately
10:36 AM PDT on August 12, 1993. Recovery Package F data analysis was
complete at 11:25 AM PDT. Real-time commands were then sent to switch high
rate telemetry to the CDS B string and low rate telemetry to the CDS A string.
Real-time commands were also sent to perform power reconfigurations and to
turn the Two-Way Non-Coherent (TWNC) off. Memory loads were then uplinked for
execution of a SITURN and Trajectory Correction Maneuver (TCM) No. 20 on
August 13, 1993.
9. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 158 DN (18.6 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
10. The Spacecraft status as of August 12, 1993, is as follows:
a) System Power Margin - 33 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.14rpm/Star Scanner
d) Spacecraft Attitude is approximately 21 degrees
off-sun (lagging) and 5 degrees off-earth (lagging)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EPD, SSI, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 263 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Trajectory Correction Maneuver (TCM) No. 20 sequence memory load was
approved for transmission by the Project on August 11, 1993. TCM-20 is a
one-portion maneuver scheduled to execute on August 13, 1993 consisting of
one axial and one lateral segment. The estimated total delta velocity is
0.62 m/sec.
GDS (Ground Data Systems): Nothing significant to report this week
TRAJECTORY
As of noon Thursday, August 12, 1993, the Galileo Spacecraft trajectory
status is as follows:
Distance from Earth 495,880,900 km (3.32 AU)
Distance from Sun 423,884,000 km (2.84 AU)
Heliocentric Speed 66,700 km per hour
Distance from Jupiter 406,551,900 km
Round Trip Light Time 55 minutes, 12 seconds
SPECIAL TOPIC
1. As of August 12, 1993, a total of 72263 real-time commands have been
transmitted to Galileo since Launch. Of these, 65549 were initiated in the
sequence design process and 6714 initiated in the real-time command process.
In the past week, 313 real time commands were transmitted; one was initiated
in the sequence design process and 312 initiated in the real-time command
process. Major command activities included commands to reset the command loss
timer, modify telemetry Map 3, perform a cruise science MRO, reconfigure and
restart the CDS A string, switch the high rate telemetry to the CDS B string
and low rate telemetry to the CDS A string, perform power reconfigurations,
turn the TWNC off, and uplink a SITURN and TCM-20 sequence memory load.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.868 | Galileo Update -- 08/16/93 | TINCUP::J_BUTLER | E pur, si muove... | Mon Aug 16 1993 19:39 | 33 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 16, 1993
IDA -12 Days
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, the uplink of EJ-2'' (Earth-Juptiter) sequence memory
load and real-time commands to perform engineering reconfigurations were
performed on Sunday, as planned. Tracking was scheduled over DSS-43 (Canberra
70 meter antenna), DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone
70 meter antenna).
Today, August 16, 1993, a routine RPM (Retro-Propulsion Module) thruster
flushing maintenance activity is scheduled. The NIMS (Near Infrared Mapping
Spectrometer) instrument is scheduled to be power on. Tracking is scheduled
over DSS-14.
Tomorrow, optical navigation #4 is scheduled to be shuttered, along with
the start of data playback. A cruise science memory readout and SSI (Solid
State Imaging camera) memory readout are scheduled. Wobble compensation and
identification are also scheduled. Tracking is scheduled over DSS-63, DSS-14
and DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | When given a choice between
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | two exciting things, choose
|_____|/ |_|/ |_____|/ | the one you haven't tried.
|
| 560.869 | Galileo Update -- 08/17/93 | TINCUP::J_BUTLER | E pur, si muove... | Wed Aug 18 1993 19:46 | 33 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 17, 1993
IDA -11 Days
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, a routine RPM (Retro-Propulsion Module) thruster flushing
maintenance activity was performed, as planned. The NIMS (Near Infrared
Mapping Spectrometer) instrument was powered on. Tracking was scheduled
over DSS-14 (Goldstone 70 meter antenna).
Today, August 17, 1993, optical navigation #4 is scheduled to be
shuttered, along with the start of data playback. A cruise science memory
readout and SSI (Solid State Imaging camera) memory readout are scheduled.
Wobble compensation and identification activities are also scheduled.
Transitioning to the all-spin mode and flushing the S thrusters are also
planned. Tracking is scheduled over DSS-63 (Madrid 70 meter antenna), DSS-14
and DSS-43 (Canberra 70 meter antenna).
Tomorrow, the playback of optical navigation #4 data is scheduled to
continue. A USO (Ultra Stable Oscillator) test is also scheduled Tracking is
scheduled over DSS-43, DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.870 | Galileo Updates 1 & 2 -- 08/18/93 | TINCUP::J_BUTLER | E pur, si muove... | Wed Aug 18 1993 19:46 | 70 |
|
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
August 18, 1993
The Galileo spacecraft is 512 million kilometers (318
million miles) from Earth and 430 million kilometers (267 million
miles) from the Sun, preparing for its second asteroid encounter
on August 28.
Galileo will fly about 2,400 kilometers (1,500 miles) from
the asteroid Ida, at a relative speed of 12.4 km per second
(almost 28,000 mph), at 9:52 a.m. PDT on Saturday, August 28;
radio signals indicating the event will take almost 30 minutes to
reach Earth.
Yesterday afternoon the spacecraft obtained its second
optical navigation image (a long exposure of the sky showing Ida
and background stars) to refine knowledge of Ida's location; one
more is planned. The data are being played back this week. Last
Friday Galileo performed the first of two trajectory-correction
maneuvers designed to refine the flight path for the desired Ida
flyby. The second maneuver is scheduled for August 26, just two
days before the encounter.
The spacecraft is communicating through its low-gain antenna
at 40 bits per second, and its health and performance are good.
*********
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT (#2 jb)
August 18, 1993
IDA -10 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, optical navigation #4 was shuttered along with the start of
data playback, as planned. A cruise science memory readout and SSI (Solid
State Imaging camera) memory readout were performed. Wobble compensation and
identification activities were also executed. Transitioning to the all-spin
mode and flushing the S-thrusters were also completed. Tracking was scheduled
over DSS-63 (Madrid 70 meter antenna), DSS-14 (Goldstone 70 meter antenna)
and DSS-43 (Canberra 70 meter antenna).
Today, August 18, 1993, the playback of optical navigation #4 data is
continuing. A USO (Ultra Stable Oscillator) test is also scheduled. Tracking
is scheduled over DSS-43, DSS-63 and DSS-14.
Tomorrow, the playback of optical navigation #4 data is scheduled to
continue. Real-time commands are scheduled to transition from the all-spin to
the dual-spin mode and to turn off the Plasma Wave calibration tone. A science
reconfiguration mini-sequence is also scheduled to be uplinked. Tracking is
scheduled over DSS-43, DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.871 | Galileo Update -- 08/19/93 | PONIL::J_BUTLER | E pur, si muove... | Fri Aug 20 1993 13:26 | 33 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 19, 1993
IDA -9 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, the playback of optical navigation image #4 data continued, as
planned. A USO (Ultra Stable Oscillator) test was also performed. Tracking
was scheduled over DSS-43 (Canberra 70 meter antenna), DSS-63 (Madrid 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, August 19, 1993, the playback of optical navigation #4 data is
continuing. Real-time commands are scheduled to transition from the all-spin
to the dual-spin mode and to turn off the Plasma Wave calibration tone. A
science reconfiguration mini-sequence is also scheduled to be uplinked. DACs
(Delayed Action Commands) to transition from the dual-spin to the all-spin mode
after shuttering optical navigation image #5 are also scheduled. Tracking is
scheduled over DSS-43, DSS-63 and DSS-14.
Tomorrow, the playback of optical navigation image #4 is scheduled to
complete. The science reconfiguration mini-sequence is scheduled to execute.
Tracking is scheduled over DSS-43 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.872 | Bit Rate Information | PONIL::J_BUTLER | E pur, si muove... | Fri Aug 20 1993 13:56 | 59 |
|
In article <N4HY.93Aug19140359@harder.ccr-p.ida.org>, n4hy@harder.ccr-p.ida.org (Bob McGwier) writes...
>
>What will be the bit rate at Jupiter?
Galileo will be transmitting at 10 bits/second from Jupiter. However, the
images will be compressed by a factor of 10, and improvements in the Deep
Space Network give another 10x improvement, so the effective bit rate will be
1000 bps.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
********
In article <19AUG199320563271@kelvin.jpl.nasa.gov>
baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:
>Galileo will be transmitting at 10 bits/second from Jupiter. However, the
>images will be compressed by a factor of 10, and improvements in the Deep
>Space Network give another 10x improvement, so the effective bit rate will be
>1000 bps.
How can DSN improvements cause higher data rates without Galileo increasing
its transmission rate? Should I read this as "Galileo would transmit at 10
bps if we used the current system, but the improved system will allow it
to transmit at 100 bps"?
--
John Carr (jfc@athena.mit.edu)
******
In article <250sjo$18l@senator-bedfellow.MIT.EDU>, jfc@athena.mit.edu (John F Carr) writes...
>In article <19AUG199320563271@kelvin.jpl.nasa.gov>
> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:
>
>>Galileo will be transmitting at 10 bits/second from Jupiter. However, the
>>images will be compressed by a factor of 10, and improvements in the Deep
>>Space Network give another 10x improvement, so the effective bit rate will be
>>1000 bps.
>
>How can DSN improvements cause higher data rates without Galileo increasing
>its transmission rate? Should I read this as "Galileo would transmit at 10
>bps if we used the current system, but the improved system will allow it
>to transmit at 100 bps"?
>
That's correct, I just phrased it wrong.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.873 | Mission Director Status Report -- 13-19 Aug 1993 | PONIL::J_BUTLER | E pur, si muove... | Mon Aug 23 1993 13:37 | 181 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 13 - 19, 1993
SPACECRAFT
1. On August 13, an Energetic Particle Detector (EPD) motor maintenance
exercise was performed which stepped the instrument through its eight sector
positions and then to Sector 0 which is the predicted least contamination
position in preparation for the execution of TCM-20 (Trajectory Correction
Maneuver #20). The EPD instrument was returned to Sector 4 on August 15, 1993
via real-time commanding.
2. On August 13, the spacecraft, under stored sequence control, performed
approximately a 10-degree unbalanced SITURN for the purpose of attitude
maintenance. The Z thrusters were used during the activity.
3. On August 13, Trajectory Correction Maneuver (TCM) No. 20 was performed
on the spacecraft. The maneuver consisted of one axial and one lateral
segment imparting a total delta velocity of approximately 0.62 m/sec. This
maneuver was executed at 40 bps with the spacecraft pointed approximately
12 degrees off the sun.
All RPM (Retro-Propulsion Module) pressures and temperatures and attitude
control indicators were near predicted levels. The sequence planned spin and
pointing corrections were not executed because they were not needed.
Preliminary radio navigation data indicates a 0.1 percent overburn in the
axial segment.
4. On August 15, real-time commands were sent to turn the Near-Infrared
Mapping Spectrometer (NIMS) heater off in preparation for the NIMS instrument
being turned on August 16 and subsequent data gathering activities.
5. On August 15, the EJ-2 (Earth-Jupiter #2) double prime sequence memory load
was uplinked to the spacecraft without incident. This sequence covers
spacecraft activities from August 16, 1993 to August 27, 1993 and includes IDA
optical navigation images No. 4 through 5 and a window for the IDA approach
Trajectory Correction Maneuver (TCM) No.21.
6. On August 15, Delayed Action Commands were sent to perform a wobble
compensation on August 17, 1993. The DACs to slew the Radioisotope
Thermoelectric Generator (RTG) booms executed just prior to the execution of
the sequence controlled wobble identification activity. Initial analysis
indicates the wobble changed from 0.57 mrad to 0.17 mrad.
7. On August 16, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
8. On August 16, a periodic RPM 10-Newton thruster flushing maintenance
activity was performed. Ten of the twelve thrusters were flushed; the
S-thrusters were flushed on August 17 as the spacecraft transitioned to the
all-spin mode for the playback of the optical navigation No. 4 image data.
9. On August 17, a cruise science Memory Readout (MRO) was performed for the
Magnetometer (MAG) instrument. Preliminary analysis indicates the MRO executed
properly.
10. On August 17, the optical navigation No. 4 image was shuttered. Memory
Readouts (MROs) of the data is scheduled to complete on August 20, 1993.
Additionally, after the shuttering activity, Memory Readouts (MROs) were
performed for the Solid State Imaging (SSI) camera which indicated the camera
was operating nominally.
11. On August 17, Delayed Action Commands (DACs) were sent to turn the
Photometric Calibration Target (PCT) heater No. 1 on in preparation for the
S-thruster flushing mini-sequence activity and then back off the following day.
12. On August 17, a mini-sequence was uplinked to transition the spacecraft
from the dual-spin to the all-spin mode at 7:00 PM PDT and to flush the
S-thrusters.
13. On August 18, an Ultra-Stable Oscillator (USO) test was performed to
verify the health status of the USO and to collect gravitational red shift
experiment data; long term trend analysis is continuing.
14. On August 19, real-time commands were sent to transition the spacecraft
from the all-spin to the dual-spin mode at approximately 2:32 PM PDT in
preparation for shuttering the optical Navigation image No. 5 on August 21,
1993. The time of this mode transition was optimized to receive the majority
of the optical navigation No. 4 image playback and still provide recovery time
prior to shuttering the optical navigation No. 5 image in the event of a CDS
(Command & Data Subsystem) transient bus reset anomaly during or shortly after
the transition.
15. On August 19, Delayed Action Commands (DACs) were sent to transition the
spacecraft from the dual-spin to the all-spin mode on August 21 after the
optical navigation image No. 5 is shuttered. This action is taken to reduce
the likelihood of a CDS transient bus reset anomaly as discussed above.
16. On August 19, a science reconfiguration mini-sequence was uplinked to the
spacecraft without incident. This mini-sequence will turn on science
instruments in preparation for the IDA encounter and turns off the Spin
Bearing Assembly (SBA) supplemental heater No. 1.
17. On August 19, real-time commands were sent to turn the Plasma Wave (PWS)
instrument calibration tone off. This reconfigured the PWS instrument for
the upcoming IDA encounter.
18. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 157 DN (18.5 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
19. The Spacecraft status as of August 19, 1993, is as follows:
a) System Power Margin - 69 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.14rpm/Star Scanner
d) Spacecraft Attitude is approximately 13 degrees
off-sun (lagging) and 3 degrees off-earth (leading)
e) Downlink telemetry rate/antenna- 40bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EPD, SSI, HIC, NIMS, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 263 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-2 double prime sequence memory load was approved by the Project on
August 13, 1993. The use of double prime is a naming convention which
distinguishes the EJ-2 and EJ-2 prime sequences from the EJ-2 double prime
sequence. Changes to the EJ-2 sequence included eliminating events which had
previously executed or which had been lost due to safing. Also, the RPM
thruster flushing maintenance activity was modified to remove the flushing of
the S-thrusters. This sequence covers spacecraft activities form August 16,
1993 to August 27, 1993.
GDS (Ground Data Systems):
1. The Galileo and MOSO Change Boards approved the on-line request for
MGDS V18.1.1 on Thursday August 12 and Tuesday, August 17, respectively.
The MGDS V18.1.1 updates corrected two failures (Ref. FR 80506) in the MGDS
Command Subsystem which (1) precluded the proper printing of Single Frame
Messages, and (2) did not print DAC messages with correct SCET and SCLK
values. Without the fix, both errors represented arduous workarounds in
the command validation process.
TRAJECTORY
As of noon Thursday, August 19, 1993, the Galileo Spacecraft trajectory
status is as follows:
Distance from Earth 514,714,900 km (3.44 AU)
Distance from Sun 431,472,800 km (2.89 AU)
Heliocentric Speed 65,600 km per hour
Distance from Jupiter 401,023,200 km
Round Trip Light Time 57 minutes, 18 seconds
SPECIAL TOPIC
1. As of August 19, 1993, a total of 72280 real-time commands have been
transmitted to Galileo since Launch. Of these, 65551 were initiated in the
sequence design process and 6729 initiated in the real-time command process.
In the past week, 17 real time commands were transmitted; two were initiated
in the sequence design process and 15 initiated in the real-time command
process. Major command activities included commands to turn the NIMS shield
heater off, uplink the EJ-2 double prime sequence memory load, perform a
wobble compensation, return the EPD to Sector 4, reset the command loss timer,
uplink the S-thruster flushing mini-sequence, turn the PCT heater No. 1 on
and off, turn the PWS calibration tone off, transition to the dual-spin mode,
uplink a science reconfiguration mini-sequence, and transition to the
all-spin mode.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.874 | More Information on DSN Upgrades... | PONIL::J_BUTLER | E pur, si muove... | Mon Aug 23 1993 13:40 | 80 |
|
In article <2560sb$ctt@access.digex.net> prb@access.digex.net (Pat) writes:
>In article <wa2iseCC4D78.6Ks@netcom.com> wa2ise@netcom.com (Robert Casey)
>writes:
>|>>Sorry if this has been explained before, but precisely how will the
>|>>DSN upgrades realize the 10x improvement? Receiver performance is
>|>I suppose that NASA and JPL will borrow some big radio astromony dishes, like
>|>the VLA (I think they used it for Voyager 2 at Uranus and Neptune).
>
>I've seen some pictures of the DSN antennas being re-skinned and increased
>in diameter. I thought that was for the Galileo support activity.
Note followups directed out of sci.astro.
Re what they're doing to increase the data return from Galileo,
here are my notes from the relevant portion of the JPL press
conference in June '92.
Jon
__@/
----
Dr. Leslie Deutsch
Manager of Telecommunications, [Data something]
Will be using 4 separate techniques:
Slide: Array Antennas to capture more of the signal that gets
to Earth.
New developments since we used similar techniques to support
Voyager at Neptune. Can array at higher efficiency and more
antennas. Array within as well as between DSN complexes.
Slide: Increase the sensitivity of our Antennas
Photo - 70m Australia antenna
Australian antenna most important since Galileo appears in
Southern hemisphere during entire mission. Will be upgrading and
installing a low-noise amplifier. In addition, all antennas will
be equipped with a new set of receivers. Already planned to be
installed by Galileo tour period, but will be using in a new
configuration that will achieve 2x data rate.
Slide: Use more powerful error correcting codes.
With new codes, Galileo will be able to operate at a much
lower error rate while also allowing 50% higher data rate.
Error codes were first developed for use in deep space missions.
Basic point is to protect data so when it's corrupted by noise or
low signal strength, can still recover initial bits. Algorithm
appends a code word and transmits. On ground, decoder looks to see
what code word could have been, strip off extra bits and return
original bits to user. Galileo already has coders on board, but
new codes we will program will allow several magnitudes better
error correction while allowing 50% higher data rate.
Slide: Compression will allow information from Galileo to be
transmitted to Earth with many fewer bits.
Image compression - [looks like a discrete cosine
transform] - approximate transforms and send them to
Earth. Negligible loss of fidelity.
Lossless compression of other science data. Look for
patterns in data.
Compression ratio turns out to be 1.5-2:1 for lossless
compression. Much greater gains for imaging compression - 10-20:1.
In summary, would improve communications system using these four
techniques. Bottom line is a factor of 100 increase in science
information returned from Jupiter compared to current capability.
All these techniques come from ongoing research that will be used
in future missions.
--
Jon Leech (leech@cs.unc.edu) __@/
``One never knows... Deacon now wants to conduct population
explosion tests *underground*.'' - Molester Mole
|
| 560.875 | Galileo at Ida | PONIL::J_BUTLER | E pur, si muove... | Mon Aug 23 1993 16:26 | 50 |
|
Paula Cleggett-Haleim
Headquarters, Washington, D.C. August 23, 1993
Phone: 212/358-0883
Jim Wilson
Jet Propulsion Laboratory, Pasadena, Calif.
Phone: 818/354-5011
RELEASE: 93-149
HEADING FOR JUPITER, GALILEO TO ENCOUNTER ITS SECOND ASTEROID
NASA's Galileo spacecraft will encounter its second asteroid, called
Ida, Saturday morning, Aug. 28, on Galileo's flight to explore Jupiter.
Galileo made the world's first asteroid encounter -- with Gaspra -- in
October 1991.
At 12:52 p.m. EDT, Galileo will race through a closest approach
distance of 1,500 miles (2,400 kilometers) from Ida. Relative speed between
Galileo and Ida will be almost 28,000 miles per hour (12.4 kilometers per
second). Radio signals confirming the encounter will reach mission
controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., 30 minutes
later.
Galileo's camera and other scientific instruments will record
observations from several hours before to several minutes after the closest
point of approach to Ida. Because Galileo must use its low-gain antenna for
all communications, the pictures and other data will be played back, slowly,
in September and in the spring of 1994.
"However," Project Manager William J. O'Neil said, "we will have a data
set as good as the Gaspra encounter -- or even better."
Ida is a stony body, irregular in shape and about 20 miles (31 kilometers)
long. Ida is larger than Gaspra and orbits farther from the Sun. Ida is
believed to belong to the same asteroid type as Gaspra, though Ida is younger
and of slightly different composition.
Galileo will reach Jupiter in December 1995 to study its satellites and
its magnetosphere, using an atmospheric probe and an orbiter scheduled for a
10-orbit, 23-month survey.
- end -
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.876 | Galileo Update -- 08/23/93 | CXDOCS::J_BUTLER | E pur, si muove... | Tue Aug 24 1993 11:12 | 33 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 23, 1993
IDA -5 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, the optical navigation image #5 was shuttered on
Saturday along with DACs (Delay Action Commands) to transition from dual-spin
to the all-spin mode. Cruise science memory readouts were also performed on
Saturday. Over 25% of the optical navigation image #5 playback data was
received and processed on the ground. The remainder of the optical navigation
image #5 playback data and the USO (Ultra Stable Oscillator) test data were
not received due to loss of DSN (Deep Space Network) station coverage which
was reassigned to the Mars Observer project in support of a spacecraft anomaly.
Tracking was performed over DSS-43 (Canberra 70 meter antenna) , DSS-63 (Madrid
70 meter antenna) and DSS-14 (Goldstone 70 meter antenna) on Saturday, and over
DSS-14 on Sunday.
Today, August 23, 1993, real-time commands are scheduled to switch the
downlink data rate to 10 bps. Tracking is scheduled over DSS-63 and DSS-14.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.877 | Galileo Update -- 08/24/93 | TINCUP::J_BUTLER | E pur, si muove... | Tue Aug 24 1993 21:21 | 30 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 24, 1993
IDA -4 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 10 bps (bits/second).
Yesterday, real-time commands were sent to switch the downlink data rate
to 10 bps, as planned. The EJ-3A (Earth-Jupiter #3A) sequence memory load
was also uplinked. Tracking was scheduled over DSS-63 (Madrid 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, August 24, 1993, DACs (Delayed Action Commands) are scheduled to
be sent which will perform all-spin and dual-spin mode transitions early in
the EJ-3A and EJ-3B sequence. Tracking is scheduled over DSS-63 and DSS-43
(Canberra 70 meter antenna).
Tomorrow, the EJ-3B sequence memory load is scheduled to be uplinked.
Tracking is scheduled over DSS-14 and DSS-43.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.878 | Galileo Update -- 08/25/93 | TINCUP::J_BUTLER | E pur, si muove... | Thu Aug 26 1993 14:52 | 30 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 25, 1993
IDA -3 Days
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 10 bps (bits/second).
Yesterday, DACs (Delayed Action Commands) were sent which will perform
all-spin and dual-spin mode transitions early in the EJ-3A (Earth-Jupiter #3A)
and EJ-3B sequence. Tracking was scheduled over DSS-63 (Madrid 70 meter
antenna) and DSS-43 (Canberra 70 meter antenna).
Today, August 25, 1993, the EJ-3B sequence memory load is scheduled to
be uplinked. Tracking is scheduled over DSS-43.
Tomorrow, the DAC to transition from the all-spin to the dual-spin mode
in preparation for the Ida encounter is scheduled to execute at 6:29 AM PDT.
Tracking is scheduled over DSS-43, DSS-63 and DSS-14 (Goldstone 70 meter
antenna).
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.879 | Galileo Update -- 08/26/93 | TINCUP::J_BUTLER | E pur, si muove... | Thu Aug 26 1993 19:22 | 28 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 26, 1993
IDA -2 Days
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 10 bps (bits/second).
Yesterday, the EJ-3B (Earth-Jupiter #3B) sequence memory load was
uplinked, as planned Tracking is scheduled over DSS-43 (Canberra 70 meter
antenna).
Today, August 26, 1993, the DAC (Delayed Action Command) to transition
from the all-spin to the dual-spin mode in preparation for the Ida encounter
executed at 6:29 AM PDT. Tracking is scheduled over DSS-43, DSS-63 (Madrid
70 meter antenna) and DSS-14 (Goldstone 70 meter antenna).
Tomorrow, the EJ-3A sequence memory load is scheduled to start. Tracking
is scheduled over DSS-43, DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.880 | Mission Director Status Report -- 20-26 Aug 1993 | PONIL::J_BUTLER | E pur, si muove... | Thu Aug 26 1993 22:07 | 131 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 20 - 26, 1993
SPACECRAFT
1. On August 20, Memory Readouts (MROs) of the optical navigation image No. 4
were completed as scheduled. Additionally, the science reconfiguration
mini-sequence executed in preparation for the upcoming Ida encounter.
2. On August 21, cruise science Memory Readouts (MROs) were performed for the
Dust Detector (DDS), Magnetometer (MAG), and Extreme Ultraviolet Spectrometer
(EUV) instruments. Preliminary analysis indicates the data was received
nominally.
3. On August 21, optical navigation image No. 5 was shuttered. Memory
Readouts (MROs) of the data began and over 25 percent of the data was received
and processed on the ground. The remainder of the data was not received due
to loss of DSN (Deep Space Network) station coverage which was reassigned to
the Mars Observer Project in support of a spacecraft anomaly. Additionally,
after the shuttering activity, Memory Readouts (MROs) were performed for the
Solid State Imaging (SSI) camera which indicated the camera was operating
nominally. Delayed Action Commands (DACs) also executed at 1132 AM PDT to
transition the spacecraft from the dual-spin to the all-spin mode to reduce
the likelihood of a CDS (Command and Data Subsystem) bus reset anomaly during
the MRO data collection activity.
4. On August 22, an Ultra-Stable Oscillator (USO) test was performed to verify
the health status of the USO and to collect gravitational red shift experiment
data. The data was not received due to loss of DSN station coverage as
discussed above.
5. On August 23, real-time commands were sent to switch the downlink data
rate from 40 to 10 bps in accordance with telecom predicts which indicated
the 40 bps (coded) downlink capability would soon not be available at the
planned spacecraft attitude.
6. On August 23, the EJ-3A (Earth-Jupiter #3A) sequence memory load was
uplinked to the spacecraft over DSS-14 (Goldstone 70 meter antenna). The load
was not verified as being received by the spacecraft due to the limited ground
station coverage as a result of the Mars Observer spacecraft anomaly. The load
was subsequently verified over the DSS-63/43 (Madrid/Canberra 70 meter antenna)
tracks on August 24, 1993.
7. On August 24, Delayed Action Commands (DACs) were sent to perform
dual-spin/all-spin mode transitions through August 28, 1993. The time of the
transitions were chosen to maximize the time in the all-spin mode while still
providing recovery time prior to the Ida encounter in the event of a CDS
transient bus reset anomaly during or shortly after the transition to dual-spin
in preparation for encounter operations. Also, Memory Readouts (MROs) were
performed for the Solid State Imaging (SSI) camera which indicated the camera
was operating nominally.
8. On August 25, the EJ-3B sequence memory load was uplinked to the spacecraft
without incident. The load was not completely verified as being received by
the spacecraft due to the limited ground station coverage as discussed above.
The load was subsequently verified over the DSS-63 track on August 26, 1993.
9. On August 26, the spacecraft transitioned from the all-spin to the
dual-spin mode at 6:29 AM PDT in preparation for the Ida encounter which will
occur August 28, 1993.
10. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 18 DN
(4.1 volts). The DC measurement reads 159 DN (18.8 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
11. The Spacecraft status as of August 26, 1993, is as follows:
a) System Power Margin - 59 watts
b) Spin Configuration - Dual-Spin
c) Spin Rate/Sensor - 3.14rpm/Star Scanner
d) Spacecraft Attitude is approximately 14 degrees
off-sun (lagging) and 0 degrees off-earth
e) Downlink telemetry rate/antenna- 10bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, SSI, HIC, NIMS, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 241 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The EJ-3 sequence memory load was approved for transmission by the Project
on August 20, 1993. This sequence covers spacecraft activities from August 27
to September 27, 1993 and includes the Ida closest approach on August 28 and
the initial return of science data.
GDS (Ground Data Systems): Nothing significant to report.
TRAJECTORY
As of noon Thursday, August 26, 1993, the Galileo Spacecraft trajectory
status is as follows:
Distance from Earth 532,806,900 km (3.56 AU)
Distance from Sun 438,950,800 km (2.94 AU)
Heliocentric Speed 64,500 km per hour
Distance from Jupiter 395,684,800 km
Round Trip Light Time 59 minutes, 18 seconds
SPECIAL TOPIC
1. As of August 26, 1993, a total of 72292 real-time commands have been
transmitted to Galileo since Launch. Of these, 65554 were initiated in the
sequence design process and 6738 initiated in the real-time command process.
In the past week, 12 real time commands were transmitted; three were initiated
in the sequence design process and 9 initiated in the real-time command
process. Major command activities included commands to switch from 40 to
10 bps downlink data rate, uplink the EJ-3A sequence memory load, perform
dual-spin/all-spin mode transitions, and uplink the EJ-3B sequence memory
load.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.881 | Galileo Update -- 08/27/93 | PONIL::J_BUTLER | E pur, si muove... | Fri Aug 27 1993 19:08 | 34 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 27, 1993
IDA -1 Day
The Galileo Spacecraft is operating normally in the dual-spin mode and
is transmitting coded telemetry at 10 bps (bits/second).
Yesterday, the DAC (Delayed Action Command) to transition from the
all-spin to the dual-spin mode in preparation for the Ida encounter executed
at 6:29 AM PDT. Tracking was scheduled over DSS-43 (Canberra 70 meter
antenna), DSS-63 (Madrid 70 meter antenna) and DSS-14 (Goldstone 70 meter
antenna).
Today, August 27, 1993, the EJ-3A (Earth-Jupiter #3A) sequence memory
load went active. A SITURN is scheduled this evening to position the
spacecraft's attitude for the Ida encoutner. Tracking is scheduled over
DSS-43, DSS-63 and DSS-14.
Over the weekend, Ida's closest approach is scheduled to occur at
9:52 AM PDT on Saturday. A SITURN is scheduled after closest approach on
Saturday. DACs are also scheduled to be uplinked on Saturday which will
perform mode transitions throughout the remainder of the EJ-3 sequence.
Tracking is schedule over DSS-43, DSS-63 and DSS-14 on Saturday and Sunday.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.882 | Galileo Update -- 08/28/93 -- Good News for Galileo | CXDOCS::J_BUTLER | E pur, si muove... | Sun Aug 29 1993 04:57 | 17 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 28, 1993
IDA Flyby
Real-time engineering data confirms that the Galileo spacecraft
successfully accomplished the Ida encouter on Saturday, August 28, 1993.
The science data will be played back over the next several weeks using
the Low Gain Antenna.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.883 | Long Reply Warning: Galileo at Ida Encounter Notebook | PONIL::J_BUTLER | E pur, si muove... | Mon Aug 30 1993 19:38 | 8 |
| The next note is the "Galileo at Ida Encounter Notebook."
It is over 1000 lines long, so DECwindows Notes users may have time
for a quick lunch while waiting to read it... :)
Regards,
John B.
|
| 560.884 | Galileo at Ida Encounter Notebook | PONIL::J_BUTLER | E pur, si muove... | Mon Aug 30 1993 19:38 | 1001 |
|
GALILEO IDA ENCOUNTER NOTEBOOK
August 1993
1.0 INTRODUCTION
The Galileo spacecraft's Venus-Earth-Earth gravity assist (VEEGA)
trajectory provided two opportunities to make close observations
of asteroids. On October 29, 1991, Galileo encountered the first
of these asteroids, Gaspra, at a distance of 1,601 km. Most of
the data gathered at Gaspra were recorded for playback in
November 1992 when the spacecraft was again in the vicinity of
Earth.
The opportunity to visit Gaspra and Ida was not the result of
celestial good fortune but was in fact the result of careful
trajectory design. A NASA policy put into effect after the start
of the Galileo program required that all missions which pass
through the asteroid belt make a close observation of an asteroid
if at all possible. This policy was applied retroactively to the
Galileo program. The asteroid belt (defined here as that region
lying between the orbits of Mars and Jupiter where the vast
majority of discovered asteroids reside) extends from
approximately 2 to 3.5 astronomical units (AU) from the Sun (one
AU equals Earth's mean distance from the Sun). Galileo would
pass through this region twice -- during the Earth-Earth leg when
it encountered Gaspra, and during the Earth-Jupiter leg when it
will encounter Ida.
The orbits of more than 4,000 asteroids were checked for possible
candidates which would allow for a successful VEEGA transfer to
Jupiter with acceptable propellant consumption to achieve a close
asteroid flyby. Few of these candidates survived the first look,
however, due to the strict timing requirements for a successful
VEEGA trajectory. Remaining candidate asteroids were then
processed with trajectory optimization software to determine
which would be the best targets. Gaspra and Ida were chosen due
to their accessibility and the low propellant cost required to
divert Galileo to them.
1.1 Organization of Document
The basics of the Ida encounter, not including the details of
experiment design and science objectives, are provided in
Sections 1.0 through 3.0. Section 4.0 provides a summary of the
science objectives and a comprehensive description of each
instrument.
1.2 Background
Galileo was launched from the Kennedy Space Center aboard the
space shuttle Atlantis on October 18, 1989. Correct alignment of
all the planets involved required that Galileo be launched
between October 12 and November 21, 1989. In the sometimes
backwards and upside-down world of orbital mechanics, it is often
necessary to slow down in order to go faster. The Inertial Upper
Stage (IUS) actually expended most of its energy to slow Galileo
down from the Earth's orbital velocity which it shared so that it
would fall in towards the Sun. The spacecraft made its closest
approach to Venus on February 10, 1990 at which time the planet's
orbital energy provided a net increase in speed relative to the
Sun of 2.2 km/sec or approximately 5,000 mph. This sent Galileo
on a trajectory that carried it around the Sun and back to Earth.
Galileo passed 960 km (596 mi) from Earth's surface on December
8, 1990. Earth provided an additional speed increase of 5.2
km/sec or approximately 11,600 mph. During its Earth-Earth leg,
Galileo passed 1,601 km (995 mi) from the center of Gaspra on
October 19, 1991. Galileo continued on its Earth-Earth
trajectory and returned to Earth for the last time on December 8,
1992 passing 303 km (188 mi) over the South Atlantic. At that
time, Galileo received an additional boost of 3.7 km/sec (8,300
mph), enough energy to reach Jupiter as planned on December 7th,
1995. Ida will be Galileo's final detour before reaching the
veils of the largest planet in our solar system.
1.3 The Study of Asteroids
Asteroids have fascinated astronomers since their discovery
almost 200 years ago. There are many questions which scientists
hope to answer through studying asteroids, questions which extend
far beyond the esoteric realm of pure science and answers that
may help us understand the forces that shaped the solar system
and life on Earth.
One of the most important reasons scientists are so interested in
asteroids is that they are believed to represent "leftovers" from
early planetary formation. Current theory holds that asteroids
are, or are remnants of, planetesimals, the small accumulations
of material from which the planets were formed. Four and a half
billion years ago, processes of accretion led to fewer but larger
planetesimals. In time, some of these became massive enough that
their gravity began to draw other planetesimals to them. Once
this point was reached, they quickly gathered up most of the
remaining planetesimals and nebular material to become the
planets we now know.
In the region between Mars and Jupiter, however, the
planetesimals never became large enough to form a planet. This
is most likely due to the strong gravitational influence of
Jupiter. Asteroids, therefore, are composed of some of the
oldest material left in the solar system and can provide an
invaluable tool for understanding the processes that went into
planetary formation, as well as the composition and physical
state of the young solar system. They are believed to be a major
source of meteorites, from which we have received much of our
knowledge about the age of the solar system and chemical
composition of the early solar nebula.
Scientists are interested in the question of why no planet formed
between Mars and Jupiter, and how the asteroids and their region
of the solar system have changed. Asteroids are continually
being bombarded and in many cases broken up into smaller
asteroids through collisions. Their surfaces have recorded aeons
of this disruption and reaccretion. By analyzing this record,
scientists can learn much about the distribution of asteroids and
comets in the past.
The study of asteroids has evolved rapidly in the last two
centuries due largely to the advancement of observing techniques.
The first ground-based observations of an asteroid were made in
1801 when Ceres, the largest asteroid, was discovered. (The
following year, William Herschel, the discoverer of Uranus,
christened this type of planetesimal an "asteroid.") Seventy-
five years later, the first asteroid-sized satellites, Phobos and
Deimos, were discovered orbiting Mars. This was followed in 1892
with the discovery of a third asteroid-sized satellite, Amalthea,
orbiting Jupiter. In 1983, the study of asteroids made
significant strides when the Infrared Astronomical Satellite
(IRAS) was launched into Earth orbit. For the following year,
the spacecraft measured nearly 2,000 asteroids as part of its
asteroid-comet survey. In 1989, the first radar images of an
asteroid, 4769 Castalia, were made. (An asteroid is assigned a
number as soon as its orbit is determined accurately enough for
its position to be predicted and verified. Thus, Castalia was
the 4,769th asteroid with a known orbit.) In December 1992,
further advances were made when JPL scientists obtained the
highest resolution images of an Earth-approaching asteroid by
beaming a radio transmission from Goldstone's 70m antenna to the
asteroid, 4179 Toutatis. At the time, the asteroid was 4 million
kilometers (2.5 million miles) from Earth. Echoes reflected back
to Goldstone's 34m antenna from Toutatis were relayed to the 70m
station where they were decoded and processed into images. The
images revealed that Toutatis is a "contact binary" asteroid
consisting of two irregularly shaped objects with an average
diameter of about 4 and 2.5 kilometers (2.5 and 1.6 miles).
Toutatis is the most irregularly-shaped solar system object yet
seen.
Interest in, and the study of, asteroids is no longer limited to
astronomers and planetary geologists but now includes
paleontologists and biologists. There is considerable geologic
evidence that impacts by asteroids and comets played an important
role in the evolution of life on Earth and may have had a hand in
determining which species survived, and which perished. In the
last two decades, geologists have discovered that our world has
been struck by asteroids or comets many times over during its
recent past (within the last 500 million years or so). These
impacts have been recorded in layers of clay containing high
concentrations of iridium, an element not commonly found on the
Earth's surface but relatively abundant in asteroids and comets.
The iridium layer coincides closely with the extinction
approximately 65 million years ago of the dinosaurs and a large
number (perhaps 75 percent) of other life forms. The catastrophe
apparently indiscriminately affected all parts of Earth --
sparing no continent or climatic belt. Indeed, asteroids may
have even played a role in the rise of the dinosaurs: Some
scientists believe that another mass extinction of many of
Earth's species occurred 215 million years ago due to the impact
of a massive asteroid. Dinosaurs, somehow spared from this
catastrophe, may have rapidly evolved to fill the resulting
ecological void (only to suffer the same fate 150 million years
later).
Galileo may have the unique opportunity to actually witness a
series of planetary impacts during its voyage to Jupiter. In
July 1994, comet Shoemaker-Levy is expected to collide with the
giant planet. The comet was shattered into a dozen or so chunks
last year by Jupiter's gravitational tidal forces when it passed
nearby the planet. The impact could be as powerful as the one
scientists believe occurred 65 million years ago on Earth. The
force of the impact could create an unbelievable light show for a
few days as each remnant of the comet collides with Jupiter.
Galileo will be in a fortuitous position to watch these fireworks
-- the event is expected to happen on the limb of Jupiter as seen
by Galileo (but on the far side as viewed from Earth) at that
time. At this time, no firm plan exists to use Galileo to record
this event.
By teaching us about the orbital interactions and periodic
bombardments which asteroids undergo, Galileo's experiments may
be able to shed some light on many critical questions pertaining
to the origin, evolution and extinction of life. Eventually, the
study of asteroids may lead to the use of asteroidal materials in
a variety of endeavors which may prove to be of economic benefit.
1.4 What we learned at Gaspra
On October 29, 1991, a small and highly elongated asteroid 2.20
AU from the Sun made history. On that day, the asteroid known as
Gaspra became the first to be imaged at close range by a
spacecraft. Galileo shuttered a total of 16 images of Gaspra
during its encounter. By November 1992, all of the data acquired
at Gaspra had been returned to Earth.
Gaspra's highly irregular shape -- 19 by 12 by 11 kilometers (12
by 7.5 by 7 mi) -- indicates that it is a fragment of a parent
body (most likely a larger asteroid) which suffered a
catastrophic collision. Its asymmetry is not surprising since
small celestial bodies tend to be less symmetric than large ones.
Until Toutatis was imaged by ground-based radar in December 1992,
Gaspra held the distinction of being the most irregularly-shaped
object yet observed. (Comparisons of shape are measured by how
large the object's limb profile deviates from the best elliptical
fit.)
Gaspra's mean radius of about 7 km (4.2 mi) places its size
between those of the Martian satellites, Deimos and Phobos. It
has fewer craters per unit area than most planetary satellites
and no intermediate or large craters (2 to 6 km in diameter). In
addition to craters, linear features 200 to 400 m wide and up to
several kilometers long were discovered. If similar to grooves
as seen on Phobos, they are likely evidence of nearly
catastrophic impacts. Other possibilities are that the linear
features are trough-like or coalescing elongated depressions.
Gaspra's age is estimated to be 200 million years based on the
assumptions that it has a primarily rocky composition and that a
certain number of projectiles, as evidenced by the number of
visible craters, would have impacted it during its lifetime.
Most celestial objects Gaspra's size have an expected lifetime of
half a billion years; thus, Gaspra has not yet reached midlife if
the assumptions used in calculating its age are correct.
However, if the asteroid's interior is metallic rather than
rocky, its age could be significantly greater -- several billions
of years; or, if the projectile impact rate was underestimated,
Gaspra could be younger.
Measurements made by Galileo's magnetometer during the encounter
revealed that the interplanetary magnetic field was distorted
around Gaspra from 1 minute before the flyby until 2 minutes
afterward. The readings support a surprising (although still
speculative) conclusion -- Gaspra is magnetized! Two processes
which may have enabled Gaspra to achieve this state are: (1) A
molten core could have been created in Gaspra or its parent body
by heat from the decay of radioactive isotopes within the parent
body, and magnetization could have resulted from the creation of
a dynamo due to convection within the core; or (2) a strong
magnetic field (as existed early in the Sun's history) could have
magnetized Gaspra or its parent body if either solidified or was
abruptly shocked while within the field's reach.
One of the primary objectives of the Gaspra and Ida encounters is
to determine if S-class asteroids, the class to which both Gaspra
and Ida belong, are the parent bodies of either the ordinary
chondrite meteorites or the stony-iron meteorites. This is known
as the "S-asteroid debate." Ordinary chondrite meteorites are
considered primitive in comparison with the stony-iron meteorites
because the stony-irons are rich in metal and other compounds due
to the extensive melting and geochemical fractionation they
underwent within their respective parent bodies. S-class
asteroids are one of the most common type of asteroids. Their
defining feature is their surface composition -- varying
proportions of olivine and pyroxene and iron-nickel metal.
Unfortunately, a key source of data to resolve this debate -- the
mass of Gaspra -- could not be determined because mission safety
precluded the flyby distance at Gaspra being small enough to make
accurate mass measurements. However, further study of data from
Galileo's near-infrared mapping spectrometer taken at Gaspra may
help resolve this debate since it will permit searches for marked
compositional heterogeneity across the asteroid's surface. And,
since Ida is also an S-class asteroid, the likelihood of
resolving this debate grows as the Ida encounter approaches.
2.0 WHAT WE KNOW ABOUT IDA
The asteroid 243 Ida was discovered on September 29, 1884 by J.
Palisa in Vienna. The asteroid was named by a Viennese, Herr von
Kuffner, presumably due to the mythological association between
Ida and Jupiter -- Ida was a nymph who cared for the infant
Jupiter while Jupiter was in hiding from his father, Saturn, who
had threatened to eat him.
Ida, like Gaspra, is an S-type asteroid. Approximately one-sixth
of the asteroids fall within this classification. S-type
asteroids are reddish objects with moderate albedos implying that
they are composed of a mixture of pyroxene, olivine and iron.
Ida is slightly pyroxene-dominated whereas Gaspra is richer in
olivine. The significance of the pyroxene-olivine ratio is that
olivine-rich asteroids are not ordinary chondrites. This is an
important factor in the S-asteroid debate as discussed earlier.
By mapping composition units on Ida with Galileo's cameras and
its near-infrared mapping spectrometer and comparing them with
similar data from Gaspra, the S-asteroid debate could be
resolved.
Ida is a member of the Koronis family of asteroids. This implies
that some time ago a large asteroid, Koronis, suffered a
catastrophic collision and broke into many remnants (children) of
which Ida is one. Ida and the other members of this "family"
share nearly identical orbital elements -- thus meeting the
qualification of being an asteroid family. The benefit to
studying families is that by studying the offspring one is
provided with a glimpse of the interior of the parent body.
Models of the Koronis family suggest that the collision giving
rise to Ida happened only tens of millions of years ago.
During the time of closest approach, Ida will appear from Earth
to be located at right ascension 196.7 degrees, declination -8.0
degrees toward the constellation Virgo. Ida will be 3 to 4
degrees northwest of Spica, Virgo's brightest star.
Ida's known characteristics are summarized in the following table
(Gaspra's characteristics are provided as a comparison):
IDA vs. GASPRA
A Brief Comparison
-- Ida is almost twice as large in diameter and eight times as
large in volume (Ida can be represented as a triaxial ellipsoid
with the following dimensions: 53 km by 23 km by 18 km with a
mean diameter of 28 km (17.4 mi) vs. 19 km by 12 km by 11 km with
a mean diameter of 14 km (8.4 mi)) for Gaspra)
-- Ida is in the middle of the asteroid belt (Gaspra is located
in the inner edge)
-- Ida has a more rapid spin rate (Ida's spin period = 4.63
hours; Gaspra's spin period = 7.04 hours)
-- Ida is thought to have a more irregular shape
-- Ida is a member of the Koronis family of asteroids (Gaspra is
in the Flora family)
-- Ida may be much younger than Gaspra (tens of millions of
years as opposed to 200 million years for Gaspra)
-- Ida is possibly an ordinary chondrite (most common meteorite)
parent body (Gaspra is possibly a stony-iron meteorite parent
body)
3.0 PREPARING FOR THE ENCOUNTER
The three main challenges in planning for a successful encounter
at Ida were (1) to identify Ida's position with respect to the
Galileo spacecraft with as high a degree of certainty as
possible; (2) to prepare the spacecraft to point the instruments
on target; and (3) to develop a data return strategy which will
optimize the science return. The first two objectives were
especially challenging due to Ida's small size and ephemeris
uncertainty. The third objective, an optimized data return
strategy, was also challenging due to data rate limitations and
constraints on the use of the non-redundant onboard tape
recorder.
3.1 Navigating to Ida
Precise knowledge of Ida's orbit only became of interest to
astronomers after it was selected as a flyby target for Galileo.
Thus, a long-term record of regular Ida observations which the
navigation team could rely on to assist in the determination of
Ida's orbit did not exist. Instead, ground-based observations of
Ida combined with Doppler and range measurements of the
spacecraft are being used to narrow the position uncertainty of
both Ida and Galileo. Additionally, star-position data acquired
by the Hipparcos spacecraft was used to update Ida's apriori
ephemeris. The uncertainty in the position of Galileo relative
to Ida can be represented by an ellipsoidal volume of space no
larger than 530 km by 420 km by 210 km (330 by 260 by 130 mi)
(95-percent probability). Further reductions in Ida's position
uncertainty will be made by the Galileo Navigation Team prior to
closest approach through the use of optical navigation and a
technique known as single-frame mosaicking which was first
employed at Gaspra.
Optical Navigation
Optical navigation (OPNAV) consists of a series of photographs
taken by the spacecraft's imaging system of a target body against
a star background. OPNAV pictures give information on the
apparent position of the target body when compared to the known
positions of the background stars. OPNAV pictures were used by
Galileo for orbit determination purposes for the first time at
Gaspra.
Prior to the encounter, Galileo will take a total of four optical
navigation images of Ida on July 22, August 12, August 17 and
August 21 (all dates UTC) beginning with OPNAV 2. (Originally,
five OPNAV pictures were planned; however, OPNAV 1 was cancelled
due to a spacecraft safing event.) After all of the data from
the preceding OPNAV has been played back, the next OPNAV image
will be shuttered. As of this document's deadline date, OPNAV 2
has already been processed.
OPNAV 5 originally was scheduled to occur 5 days prior to
encounter but was moved back 2 days (to -7 days) in order to
accommodate the Mars Observer orbit insertion which required the
Deep Space Network 70m antennas at the same time. As a result,
OPNAV 5 will be executed and played back before the final Ida-
encounter trajectory correction maneuver (TCM 21). Thus, data
from OPNAV 5 (and OPNAV 4) will be used to adjust Galileo's
trajectory through design revisions of TCM 21.
Single-Frame Mosaicking
In order to ensure that adequate data would be returned in each
OPNAV image to allow extraction of position measurements, the
single-frame mosaic technique was conceived. This technique,
first used at Gaspra, involves performing several small scan
platform slews while the solid-state imaging instrument's camera
shutter is open. It enables several sets of Ida and star images
to be acquired in one frame. Single-frame mosaicking has 3 main
advantages over the routine OPNAV method in that it (1) decreases
the sensitivity to data outages because multiple sets of Ida and
star images can be distributed over different lines of the same
picture; (2) provides the capability to use different exposure
times for each mosaic position since the stop times between the
mosaic slews can be varied; and (3) allows an area larger than
the size of the camera field-of-view to be covered by scan
platform motions.
3.2 Instrument Pointing
Galileo will fly by Ida in the southern hemisphere (75 degrees
south ecliptic latitude) on the asteroid's dark side, passing
approximately 2,400 km (1,500 mi) from the center of the asteroid
while traveling at a speed relative to the asteroid of 12.4
km/sec (27,700 mph). The volume of space corresponding to Ida's
position uncertainty, when projected onto the plane normal to the
pointing direction of the scan platform, represents an ellipse-
shaped area within which the asteroid may be found at some level
of probability. For science planning purposes, the elliptical
region of sky searched was chosen so that there would be a 95-
percent probability of capturing the asteroid within the
boundaries of the ellipse. The scan platform instruments, which
would normally be aimed directly at an object of interest,
instead must scan the entire area of position uncertainty and
record data for the entire region in order to be certain of
capturing Ida. This is a difficult task given that the target is
moving at such a high relative velocity.
Without any further improvement on the apriori knowledge of Ida's
position, it would be highly improbable to capture an image of
the asteroid greater than several dozen pixels. Fortunately,
position data obtained from OPNAV pictures can be used to
decrease significantly the position uncertainty of Ida. As
mentioned previously, the final two OPNAV pictures (OPNAV #4 and
OPNAV #5) will be used to update the design of the final pre-Ida
trajectory correction maneuver (TCM-21) in order to achieve the
best possible trajectory delivery accuracy. TCM-21 will be
executed two days prior to closest approach.
3.3 Data Return Strategy at Ida
The data return strategy developed for the Ida encounter was
designed so as to ultimately return the key science observations
at Ida -- primarily solid-state imaging and near-infrared mapping
spectrometer observations of Ida, the magnetometer search for
Ida's interaction with the solar wind, and a minimal set of
calibrations. The strategy reflects the key constraint of
limiting the tape recorder start/stop cycles required to play
back recorded data. The other Ida experiments have been designed
to use only the data that will be embedded in the return of the
solid-state imaging, near-infrared mapping spectrometer and
magnetometer observations, including the ultraviolet spectrometer
and the photopolarimeter-radiometer experiments.
There are three ways to return data collected during the Ida
encounter. The first two, unloading data which have been
transferred to the command and data subsystem from the tape
recorder (data memory subsystem memory readouts) and real-time
memory readouts of certain instruments, have been used previously
during the Galileo mission. The third method, known as the
command and data subsystem buffering technique, will be used to
acquire data from the magnetometer instrument only. This
technique, conceived of for the Ida encounter, was first employed
earlier this year for engineering purposes. It involves
immediately transferring data acquired from 1 hour before to 1
hour after closest approach to the command and data subsystem
buffer for later playback. Due to this technique, it will be
possible to obtain the magnetometer data since otherwise it would
have had to have been extracted from the solid-state imaging data
stream -- a prohibitive task.
Return of the Ida data must be apportioned between the month-long
period beginning one day after closest approach and a four-month
long period (March-June) in 1994 when the Earth is again between
the Sun and Galileo. The challenge of the data return activity
is in determining the location of data on the tape recorder
primarily due to uncertainties in both Ida's location and in scan
platform pointing. A special survey technique, known as the
"jailbar search," has been developed for Ida which allows for
sampling 2 camera lines out of every 330. Upon inspection,
packets which contain Ida data, as opposed to "black sky" data,
will be identified. Based upon the known tape recorder location
of each packet, the spacecraft will be instructed to download the
selected frames. This technique guarantees locating Ida in the
highest resolution images; thus, it will greatly reduce the
playback time needed to download the highest priority encounter
data. The total science data return at Ida is expected to be
comparable to that achieved at Gaspra.
4.0 SCIENCE OBJECTIVES AT IDA
There are four primary science objectives for the Ida encounter.
The first is to characterize global properties such as size and
shape. The second objective is to characterize surface
morphology and particle size, search for geologic and
evolutionary processes and obtain crater frequency distributions
for collisional history and relative ages. The third objective
is to characterize compositional properties such as surface
composition, chemical composition and surface mineralogy. The
fourth objective is to characterize possible magnetic field
effects by conducting a magnetometer search for field
perturbations, especially solar wind whistler wing effects, such
as apparently detected at Gaspra. Achievement of these
objectives will give scientists a basis for comparative analyses
of other asteroids and small bodies throughout the solar system.
The following is a description of the Galileo instruments to be
used during the Ida encounter.
4.1 SSI
The solid-state imaging instrument (SSI) uses a 176.5mm aperture
Cassegrain telescope to focus incident light from an object or
body of interest onto a solid-state image-detector array known as
a charge-coupled device (CCD). The focal array has a resolution
of 800 lines by 800 elements. By comparison, this is
approximately twice the resolution of conventional television.
SSI will obtain many images during the encounter, including at
least one high-resolution image of the asteroid. Galileo's
closing speed and uncertainties remaining in the orbital
parameters will make it necessary to mosaic an area that is
significantly larger than Ida itself in order to capture the
asteroid's image. While Galileo is still far enough away to
capture the entire error ellipse (at 95-percent confidence) in
one frame, SSI will take a series of 75 individual images
covering 1.08 of Ida's rotation (known as Ida's "rotation
movie"). The first 33 images will be comprised of 5 clear-filter
images, three 6-filter sets, and two 5-filter sets that are
spaced to record every 30 degrees of longitude. The remaining 42
images are contained in seven 6-filter sets shuttered every 15
degrees of longitude. These images will be most useful in
characterizing Ida's size and shape. Following completion of the
Ida rotation movie, SSI will take a series of four mosaics
representing the highest priority observations. The first mosaic
includes a 6-color single image and a 2x2 series through 4
filters. This will provide the highest resolution multispectral
imaging of Ida and will abe used to study detailed compositional
variations across the surface of the asteroid. The second mosaic
is comprised of SSI clear-filter images shuttered while the near-
infrared mapping spectrometer obtains a chemical map of Ida.
This mosaic will be used in conjunction with the following high-
resolution image to provide stereo coverage of Ida which will
assist greatly in determining its shape and size. The third
mosaic, also clear filter, will provide the highest resolution
imagery of Ida for which capture of the entire asteroid is
guaranteed. Its 30 frames will cover the entire 95-percent error
ellipse and will be acquired between 5.5 and 1 minute(s) before
closest approach. Depending upon which frames in the mosaic
actually capture the asteroid, the resolution may lie anywhere
between 26 and 48 m/pixel, with a most probable resolution of
about 40 m/pixel. The highest resolution possible in this mosaic
(26 m/pixel) is twice that achieved at Gaspra (54 m/pixel). The
final mosaic, a 15-frame clear-filter, will cover only the center
region of the error ellipse giving a 50-percent probability that
the center of the asteroid will be captured. It will start at 1
minute prior to closest approach and finish at 1 minute after
closest approach. If acquired, it will be the highest resolution
SSI data obtained at Ida (24 to 26 m/pixel). Out of all 15
images in this mosaic, Ida may appear in as many as six. At the
range the final SSI mosaic is shuttered, approximately 2,400 km,
Ida will stretch across almost three SSI fields of view. These
final two mosaics were designed so that an additional coverage of
the region of most probable capture occurs at closest approach.
These images will reveal details of Ida's surface morphology,
crater size and distribution, as well as any surface processes
which may be at work. In all, SSI will record 150 frames from
which 21 individual views of Ida could be acquired. All of the
mosaics will be taken in the last 15 minutes before closest
approach.
The imaging at Ida will provide great improvements in spatial
resolution as well as spectral coverage as compared with the
Gaspra encounter imaging. The highest possible multispectral
resolution at Ida will be twice that achieved at Gaspra (87
m/pixel at Ida compared to 160 m/pixel at Gaspra). Even more
impressive is the fact that at Ida it will be possible to achieve
more than twice the highest clear-filter resolution obtained at
Gaspra (24 m/pixel vs. 54 m/pixel). This is because at Ida
imaging will continue through periapsis until 1 minute after
closest approach; whereas the final image at Gaspra was taken 8
minutes before closest approach. Also, two additional filters
have been included in the color sequences. There are many 6-
color sets at Ida as compared to 4-color sequences at Gaspra.
This will give additional insight into the understanding of the
surface composition on Ida.
4.2 NIMS
The near-infrared mapping spectrometer (NIMS) provides imaging
and spectroscopic data for the infrared region of the spectrum
(0.7 to 5.2 micrometers wavelength). This portion of the
spectrum is important because it provides information regarding
composition, temperature and geology. The NIMS is a "push-broom
imager" (so called for the way it scans images). Its principal
components are a 9-inch Ritchey-Chretien telescope, a scanning
mirror assembly, a diffraction spectrometer with a scanning
grating, and a 17-detector focal plane array. It has wavelength
resolution capabilities of 0.027 micrometers for wavelengths
greater than 1 micrometer, and 0.014 micrometers for 0.7 to 1.0
micrometers. The NIMS is a scanning-type instrument which
creates an image by repeatedly sampling what amounts to a three-
dimensional array in X, Y and wavelength. The combination of a
diffraction grating, scan mirror and scan platform motion allow
NIMS to measure and generate images in up to 408 separate
wavelengths.
NIMS will "sweep out" mosaics to ensure imaging of the asteroid
near closest approach. During its closest approach and high
resolution observations of Ida, NIMS will scan back and forth
across the region where the asteroid is located to be certain to
capture the asteroid. (During its other observations, NIMS will
"stop and shoot.") NIMS will be performing several different
types of measurements, all of which cover the spectral range of
0.7 to 5.2 micrometers. During approach, NIMS will collect a
spectral lightcurve of Ida. The instrument will sample the Ida
surface every 90 degrees of rotation in 204 wavelengths, every 30
degrees in 102 wavelengths, and every 15 degrees in 102
wavelengths. With the combined wavelength samples it is possible
to compose a hemispherically-resolved chemical heterogeneity map
for one full rotation of the asteroid. NIMS's highest-priority
is to obtain the best possible spatial resolution of Ida's
surface with 17 wavelength samples while the instrument is in its
fixed grating mode. This is done during a collaborative SSI/NIMS
mosaic occurring at 5 minutes prior to closest approach.
NIMS data will provide information about what minerals are
present on Ida's surface, one of the clues to the asteroid's
origin. Infrared images are frequently able to discern features
which have no contrast in pictures taken in the visible spectrum.
NIMS will be able to provide more complete spectral information
on the asteroid than possible from Earth because of the
atmospheric absorption characteristics and limited spatial
resolution available. NIMS will be able to extend the range of
wavelengths sampled at Ida including measurements in the thermal
region of the spectrum. All of this will provide a better
understanding of the regolith characteristics, surface
composition and chemical heterogeneity of Ida.
4.3 UVS and EUV
The ultraviolet spectrometer (UVS) measures wavelengths between
113 and 432 nanometers. The UVS is a narrow field-of-view
scanning-type instrument like the NIMS and the photopolarimeter-
radiometer (PPR) and is mounted on the scan platform. The
instrument uses a 250-mm aperture Cassegrainian telescope coupled
with an Ebert-Fastie monochromator using three photomultipliers
as detectors. The instrument can operate in a single wavelength
monitoring mode or can record the entire spectrum between 113 and
432 nanometers. The extreme-ultraviolet spectrometer (EUV) is a
modification to the ultraviolet spectrometer instrument flown on
the Voyager spacecraft. The modifications allow the instrument
to gather spectral data in the 54 to 128 nanometer range. The
EUV is a concave objective grating spectrograph mounted on the
spun section of the spacecraft. As Galileo spins, the EUV
observes a narrow annular ribbon of space.
During the encounter, the UVS will "piggyback" with the SSI and
NIMS observations. Approximately five hours before closest
approach, the UVS will begin obtaining ultraviolet spectra over
the range 162-323 nanometers, piggybacked on fixed SSI pointing.
Two additional measurement cycles with fixed pointing, when Ida
is much smaller than the UVS field of view, follow at about -4
hours and -3 hours. The final four measurements made in the 1.5
hours before closest approach piggyback on SSI and/or NIMS
mosaics covering the Ida error ellipse. The last three of these
measurements span 113-323 nanometers. These UVS measurements
obtain data on the asteroid and its near-space environment.
The EUV will be recording data on the region near Ida as Galileo
passes by it. It cannot be predicted that Ida itself will be
captured within the field of view of the EUV. EUV will be
looking at the hydrogen, helium and oxygen spectrum of the
interplanetary background in the vicinity of Ida, while UVS will
be looking at the asteroid and its vicinity.
The UVS will attempt to measure more accurately the albedo, color
and scattering properties of Ida. The EUV and UVS will be used
to determine the presence and amount of atomic and ionic emission
from the asteroid and any associated atmosphere. An atmosphere
of a sort could be created on a body as small as Ida through
interactions with the solar wind and cosmic rays which knock
surface atoms free. Limited outgassing could also generate an
extremely thin atmosphere.
4.4 PPR
The photopolarimeter-radiometer (PPR) is a descendent of an
instrument flown on the Pioneer Venus spacecraft. It uses a 10-
cm Cassegrain Dall-Kirkham telescope to focus incident light from
the object of interest through a filter wheel. The filter wheel
determines which wavelengths are passed and which are blocked.
For polarimetry, light must pass through both a half-wave
retarder plate and a spectral filter, while for photometry the
light is passed through only the spectral filter. A second
optics path obtains background light. Light from this path is
not passed unless the instrument is performing radiometry. When
the instrument is performing photopolarimetry, the incident light
passes through the filter to a prism which splits the light into
its two separate polarization components and directs these
separate beams to two silicon photodiodes. During radiometry, an
optical chopper operating at 30 Hz alternately directs flux from
the scene-view and the space-view telescopes onto a lithium-
tantalate detector. Photometry is measured in bands centered at
618, 633, 646, 789, 830, 841 and 891 nanometers, while
polarimetry measures 410, 679 and 945 nanometers. The lithium-
tantalate radiometry detector measures incident (scene-view) and
reference (space-view) infrared radiation at 17, 21, 27, 37 and
greater than 42 micrometers.
At Ida, the PPR will measure the intensity and polarization of
reflected sunlight in the visible region of the spectrum. The
PPR will also measure thermal infrared radiation. PPR will
attempt to make observations very near closest approach
(beginning at +1 minute). To do this, it will scan the center of
the error ellipse at high resolution, then the whole ellipse at
lower resolution. On the outbound side, heading away from Ida,
PPR will map the entire 95-percent confidence ellipse as a
polarimetry study in two filter wheel positions.
Radiometric observations will result in brightness temperatures
which can be converted into thermal inertias for the regolith.
This, in turn, provides information on the size of the particles
which make up this surface layer. Polarimetry analysis of how
the particles which cover Ida polarize reflected light will
provide further information on the physical properties of the
regolith.
4.5 DDS
The dust detection subsystem (DDS) is designed to measure the
mass, electric charge and velocity of incoming particles ranging
in size from 10^-16 to 10^-7 grams (less than a ten-millionth of
a pound) and speeds between 1 and 70 km/sec. The instrument has
a fairly wide field of view, approximately 140 degrees, and is
mounted on the spun portion of the orbiter to allow it to sample
direction as well as density.
Since the DDS is mounted on the spinning portion of Galileo, it
has no specific pointing requirements for making observations
during the encounter. While Galileo is in the vicinity of Ida,
DDS will be recording impact rate, particle mass, velocity,
charge and impact direction. This data will be used to determine
particle orbits and distributions.
Data obtained by the DDS will provide additional insight on the
near-asteroid environment. Scientists hope to discover if
asteroids are accompanied by accumulations of small particles,
and whether these particles are captured by the asteroid, or are
coming from the asteroid. Because data obtained by the DDS is
stored in the instrument's memory, it will be much easier to
return to Earth. Even at the transmission rate available at
Ida's distance from Earth, return of DDS data by memory readout
will be completed within 34 hours after the encounter, making it
some of the first Ida data available for analysis.
4.6 MAG
The magnetometer (MAG) is composed of two sets of sensors mounted
on the 11-meter boom. One set is mounted at the end of the boom
and the other about 6.9 meters from the spacecraft spin axis.
This boom is located on the spinning portion of the Galileo
orbiter. The outer sensor will be used at Ida and will be
operated in the approximately nano-Tesla range. It is capable of
sensing changes in the magnetic field to hundredths of a nano-
Tesla. By way of example, the Earth's magnetic field is
approximately 50,000 nano-Teslas measured at sea level.
The MAG need not be pointed at a particular target for its
observations. Instead it sweeps through space sampling magnetic
field strength and orientation as Galileo spins. Throughout
Galileo's recent interplanetary cruise, the magnetometer has been
sampling the magnetic fields at two-hour averages. As the Ida
encounter approaches, the sampling rate will be increased. At
approximately 16 hours before closest approach, the MAG will
increase its sampling rate to sample at 1-minute averages. This
data will be stored in the instrument's memory and returned to
Earth via memory readout. For approximately 2 hours in the
immediate vicinity of Ida, MAG will operate in a special mode
with 1.33-second resolution. This data will be stored in a
command and data subsystem buffer and will be returned by memory
readouts starting 19 hours after the encounter. An additional 29
minutes of normal high-resolution data (0.22-sec resolution) will
be recorded starting 1 minute after closest approach. This data
will be played back in 1994.
The MAG will provide data on how Ida interacts with the solar
wind. The presence and strength of any magnetic field, as seen
at Gaspra, would provide additional information on Ida's history
and internal structure.
4.7 PLS
The plasma science (PLS) instrument uses electrostatic analysis
to measure the directional intensities of ions and electrons with
energy per unit charge between 0.8 and 52 keV. The instrument
employs two spherical section electrostatic analyzers to measure
the energy per charge and three sets of miniature magnets provide
the mass per unit charge of the plasma. The PLS is mounted on
the spun section of the spacecraft near the base of the
magnetometer boom. As with all fields and particles instruments
such as the DDS and MAG, the PLS sweeps through space as the
spacecraft spins, sampling in all directions successively. This
provides almost complete coverage of charged particle velocity
vectors at the spacecraft position.
PLS measurements will start at about closest approach and will
run until approximately 30 minutes past closest approach. The
PLS will analyze the plasma for a range of radial distances from
Ida.
PLS will provide measurements of the solar wind and search for
evidence of solar wind and asteroid interactions. This
information, combined with that from the other fields and
particles instruments, will provide additional understanding of
the space physics of the solar environment around Ida. Also, the
PLS will test and calibrate modes intended for the Jupiter
mission.
4.8 EPD
The energetic particle detector (EPD) can detect electrons and
ions from hydrogen to iron. It can detect ions with energies
between 20 keV and 55 MeV, electrons with energies between 15 KeV
and 11 MeV, and can determine elemental species with energies
between 10 keV and 15 MeV. The EPD consists of two separate, bi-
directional telescopes, the composition measuring system and the
low-energy magnetospheric measuring system. The instrument is
mounted on a stepping platform which is in turn located on the
spun portion of the spacecraft near the base of the magnetometer
boom. This allows the EPD to view the entire region of space
around Galileo.
The EPD will be activated approximately 20 hours prior to Ida
closest approach. The stepping platform will be activated
approximately 30 minutes before closest approach. The EPD will
scan until about 30 minutes after closest approach. The EPD will
search for energetic particles produced in the interaction
between the solar wind and the asteroid.
4.9. PWS
The plasma-wave subsystem (PWS) is used to study electric and
magnetic fields. It uses an electric dipole antenna mounted at
the end of the magnetometer boom to measure electric fields and
two search coil magnetic antennas mounted on Galileo's high-gain
antenna central post to measure magnetic fields. Spectral
characteristics of electric fields between 5 Hz and 5.6 MHz and
magnetic fields between 5 Hz and 160 kHz can be measured. High
time-resolution measurements are provided by a wideband receiver
capable of waveform measurements over bandwidths of 1 kHz, 10 kHz
and 80 kHz. Both portions of the PWS are mounted on the spun
portion of the spacecraft to more effectively measure field
strength and orientation.
PWS measurements will begin approximately at closest approach and
will continue until approximately 30 minutes after. The PWS, as
with the MAG, PLS and EPD, will look for evidence of an Ida/solar
wind interaction.
REFERENCES
"An Overview of Asteroids," by R. P. Binzel, _Asteroids II_,
edited by R. P. Binzel, T. Gehrels, M. S. Matthews, University of
Arizona Press, 1989.
"Asteroid Families: Physical Properties and Evolution," by C. R.
Chapman, P. Paolicchi, V. Zappala, R. P. Binzel, J. F. Bell,
_Asteroids II_, edited by R. P. Binzel, T. Gehrels, M. S.
Matthews, University of Arizona Press, 1989.
"Asteroid Taxonomy," by D. J. Tholen, _Asteroids II_, edited by
R. P. Binzel, T. Gehrels, M. S. Matthews, University of Arizona
Press, 1989.
"Asteroids," by Clark Chapman, _The New Solar System_, edited by
J. Kelly Beatty, Brian O'Leary, and Andrew Chaikin, (Sky
Publishing Co: Cambridge, Mass, 1981).
"Fact Sheet for the First Galileo Asteroid Target, 951 Gaspra,"
by C. R. Chapman, 1990.
"Fundamentals of Astrodynamics," by R. R. Bate, D. D. Mueller, J.
E. White, Dover Publications, 1971.
"Galileo Encounter with 951 Gaspra: First Pictures of an
Asteroid," Science, vol. 257, 18 September 1992.
"Galileo: Exploration of Jupiter's System," (NASA SP-479) by C.
M. Yeates, T. V. Johnson, L. Colin, F. P. Fanale, L. Frank, D. N.
Hunten, Scientific and Technical Information Branch, National
Aeronautics and Space Administration, 1985.
"Galileo Orbit Determination for the Gaspra Asteroid Encounter,"
by P. H. Kallemeyn, R. J. Haw, V. M. Pollmeier, F. T. Nicholson,
AIAA/AAS Astrodynamics Conference, 1992.
"Galileo Photopolarimeter/Radiometer (PPR) Experiment," by E. F.
Russell, F. G. Brown, R. A. Chandos, W. C. Fincher, L. F. Kubel,
A. A. Lacis, L. D. Travis, 1990.
"Galileo Ultraviolet Experiment," by C. W. Hord, W. E.
McClintock, A. F. Stewart, C. A. Barth, L. W. Esposito, G. E.
Thomas, B. R. Sandel, D. M. Hunter, A. L. Broadfoot, D. E.
Shemansky, J. M. Ajello, A. L. Lane, R. A. West.
"Galileo Ultraviolet Spectrometer Experiment," by C. W. Hord, et
al., Laboratory for Atmospheric and Space Physics, University of
Colorado.
"Gaspra Encounter Notebook" by Ian Claypool, Jet Propulsion
Laboratory, JPL D-9052, 1991.
_McGraw-Hill Encyclopedia of Science and Technology_, McGraw-
Hill, Inc., 1987.
"Mission Plan. Ida Encounter Cruise Activity Plan," by P. J.
Guske, Jet Propulsion Laboratory, JPL D-2347, 1993.
"OPNAV Delivery Schedule for the Galileo Ida Encounter,"
Interoffice Memorandum from P. Halamek, Jet Propulsion
Laboratory, 1993.
"Optical Navigation for the Galileo Gaspra Encounter," by R. M.
Vaughan, J. E. Riedel, R. P. Davis, W. M. Owen, Jr., S. P.
Synnott, AIAA/AAS Astrodynamics Conference, 1992.
"Origin of the Asteroid Belt," by G. W. Wetherill, _Asteroids
II_, edited by R. P. Binzel, T. Gehrels, M. S. Matthews,
University of Arizona Press, 1989.
"Physical Constants for Asteroid 243 Ida, Revision C,"
Interoffice Memorandum by B. McLaughlin, Jet Propulsion
Laboratory, 1993.
"Primitive Solar System Objects: Asteroids and Comets," by Lucy-
Ann McFadden, _Encyclopedia of Astronomy and Astrophysics_,
edited by Robert A. Meyers, (Academic Press: San Diego, 1989).
"Reevaluation of the Ida Encounter Uncertainties based upon the
latest EJ-2 Timeline," Interoffice Memorandum from P. Antreasian,
Jet Propulsion Laboratory, 1993.
"Regolith Development and Evolution on Asteroids and the Moon,"
by K. R. Housen, L. L. Wilkening, C. R. Chapman, R. J. Greenberg,
_Asteroids_ edited by T. Gehrels, University of Arizona Press,
1979.
"Revised Science Planning Package for Gaspra (1600 km Flyby; LGA
Option)," Interoffice Memorandum by J. R. Johannesen, J. L.
Pojman, Jet Propulsion Laboratory, 1991.
"Spacecraft Exploration of Asteroids: The 1988 Perspective," by
J. Veverka, Y. Langevin, R. Farquhar, M. Fulchignoni, _Asteroids
II_, edited by R. P. Binzel, T. Gehrels, M. S. Matthews,
University of Arizona Press, 1989.
"Galileo 1989 VEEGA Mission Description," by L. D'Amario, L.
Bright, D. Byrnes, J. Johannesen, J. Ludwinski, AAS/AIAA
Astrodynamics Specialist Conference, Vermont, August 1989, AAS
Paper 89-431.
- end -
|
| 560.885 | Galileo Update -- 08/31/93 | PONIL::J_BUTLER | E pur, si muove... | Wed Sep 01 1993 00:10 | 38 |
|
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
August 31, 1993
Galileo successfully completed its encounter with the
asteroid Ida on Saturday morning, gathering a tape load of image
frames and other scientific data. The flight team is studying
telemetry and selected lines of taped science data and has
verified the presence of an Ida picture on tape. Playback of the
first images is planned to begin soon, and will continue for most
of September and then resume in the spring of 1994.
Spacecraft health and performance are excellent. The
spacecraft is spinning at about 2.9 rpm, transmitting at 40 bits
per second over the low-gain antenna.
Galileo is now 3 million kilometers (almost 2 million miles)
past Ida; it came within about 2400 kilometers on Saturday. The
spacecraft is more than 444 million kilometers (276 million
miles) from the Sun, and 545 million kilometers (339 million
miles) from Earth.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.886 | Galileo Update #2 -- 08/31/93 | CXDOCS::J_BUTLER | E pur, si muove... | Wed Sep 01 1993 10:45 | 29 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
August 31, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, real-time commands were sent to switch the downlink data rate
to 40 bps. The NIMS (Near Infrared Spectrometer) and SSI (Solid State Imaging
camera) were turned off. The tape recorder was selectively read out to
determine which frames contain the Ida imaging data to help in planning
subsequent data return. Ida data was visible in two of twelve partial frames
returned on August 30. Radiometric calibration target data was also returned,
as planned. Tracking was scheduled over DSS-43 (Canberra 70 meter antenna)
and DSS-14 (Goldstone 70 meter antenna).
Today, August 31, 1993, the tape recorder search is scheduled to complete.
Tracking is scheduled over DSS-43 and DSS-14.
Tomorrow, no spacecraft activity is scheduled. Tracking is scheduled
over DSS-43, DSS-63 (Madrid 70 meter antenna) and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | The hardest thing to learn
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in life is which bridge to
|_____|/ |_|/ |_____|/ | cross and which to burn.
|
| 560.887 | Galileo Update -- 09/01/93 | PONIL::J_BUTLER | E pur, si muove... | Wed Sep 01 1993 18:26 | 28 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 1, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, the tape recorder search to determine which frames contain
Ida imaging data to help in planning subsequent data return was completed,
as planned. Tracking was scheduled over DSS-43 (Canberra 70 meter antenna)
and DSS-14 (Goldstone 70 meter antenna).
Today, September 1, 1993, no spacecraft activity is scheduled. Tracking
is scheduled over DSS-43, DSS-63 (Madrid 70 meter antenna) and DSS-14.
Tomorrow, real-time commands are scheduled to switch the downlink data
rate to 10 bps. Real-time commands are also scheduled to position the tape
recorder for subsequent Ida data playback scheduled to begin on Friday
(September 3). Tracking is scheduled over DSS-43 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Nobody notices when things
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | go right.
|_____|/ |_|/ |_____|/ |
|
| 560.888 | Mission Director Status Report -- 27 Aug - 02 Sep 93 | PONIL::J_BUTLER | E pur, si muove... | Fri Sep 03 1993 13:17 | 176 |
|
Forwarded from Neal Ausman, Galileo Mission Director
GALILEO
MISSION DIRECTOR STATUS REPORT
POST-LAUNCH
August 27 - September 2, 1993
SPACECRAFT
1. On August 27, Memory Readouts (MROs) were performed for the Solid State
Imaging (SSI) camera which indicated the camera was operating nominally.
2. Beginning on August 27 and continuing through August 30, Memory Readouts
(MROs) were performed for the Dust Detector instrument. Preliminary analysis
indicates the data was received properly.
3. On August 27, approximately 11 hours prior to IDA closest approach, the
spacecraft performed about a 29 degree unbalanced SITURN to establish the
spacecraft's attitude for the Ida encounter. The Z thrusters were used during
the activity.
4. On August 28, at approximately 1:00 AM PDT, three Plasma Detector (PLS)
telemetry readings went into alarm. The temperature readings went below the
3-210 operating limits but did not exceed the qualification limits. The
temperature changes leveled out and it was determined that no real-time
commanding was necessary.
5. On August 28, at approximately 5:06 AM PDT, it was determined that attitude
control subsystem fault protection had tripped. The gyros and the
accelerometers were autonomously turned off, the scan platform safed (to 153
degrees), and the spacecraft transitioned from inertial to cruise mode. The
fault monitor counts indicated high rates were being seen on both gyros. The
cause of the anomaly is unknown and still under investigation. Real-time
commands were developed and sent which repositioned the scan platform for
encounter observations starting at the Ida rotation movie No. 3. At the time,
the Project believed that the fault protection trip caused the loss of the
majority of the distant Ida rotation movie No. 1 and 2 observations; but the
remainder of the encounter observations starting with rotation move No. 3 were
captured. Post event telemetry analysis indicates that the rotation movie No. 2
observations may not have been lost. Data analysis is still underway. After
the fault monitor trip, the remainder of the encounter observations were taken
in cruise mode with the gyros off.
After Ida closest approach, real-time commands were sent to turn the gyros
on prior to the scheduled SITURN. The 27 degree unbalanced SITURN performed
nominally with the Z thrusters being used. Real-time commands were then sent
to turn the Bay B replacement heater on to minimize the Bay A thermal cycle as
a result of the accelerometers going off. The estimated actual Bay A thermal
cycle was about 6 degrees. Later in the evening, real-time commands were sent
to configure the spacecraft to its original configuration with the
accelerometers on and the Bay B replacement heater off. Delayed Action Commands
(DACs) also executed which maximized the time in the all-spin mode to reduce the
likelihood of a CDS (Command and Data Subsystem) transient bus reset.
6. On August 28 through 30, Memory Readouts (MROs) were performed from the
Magnetometer instrument memory and the Command and Data Subsystem (CDS) memory
to collect Magnetometer (MAG) data associated with the Ida encounter.
Magnetometer data in the CDS was very high sample rate data to cover the period
approximately plus or minus one hour around closest approach. Preliminary
analysis indicates the data was received nominally.
7. During the period from August 28 through 30, a navigation cycle was
performed. The navigation cycle provided near-continuous acquisition of doppler
data during four consecutive passes of the spacecraft over DSS-43 (Canberra 70
meter antenna), DSS-63 (Madrid 70 meter antenna), DSS-14 (Goldstone 70 meter
antenna), and then back to DSS-43.
8. On August 28, Delayed Action Commands (DACs) were sent to perform
dual-spin/all-spin mode transitions through the end of the EJ-3
(Earth-Jupiter #3) sequence. The time of the transitions were chosen to
maximize the time in the all-spin mode as discussed above. Command verification
was accomplished via Memory Readouts (MROs).
9. On August 30, a NO-OP command was sent to reset the command loss timer to
264 hours, its planned value for this mission phase.
10. On August 30, Delayed Action Commands (DACs) executed which put the
spacecraft in the dual-spin mode for a Near-Infrared Mapping Spectrometer (NIMS)
Radiometric Calibration Target (RCT) calibration and then returned the
spacecraft to the all-spin mode. The time in dual-spin was approximately two
hours.
11. On August 30, the Near-Infrared Mapping Spectrometer (NIMS) and the Solid
State Imaging (SSI) camera were turned off.
12. On August 30, real-time commands were sent to switch the downlink data rate
from 10 to 40 bps as planned in the EJ-3 sequence.
13. On August 27, 28 and 30, Memory Readouts were performed for the Extreme
Ultraviolet Spectrometer (EUV) instrument. Analysis indicates the data was
received properly.
14. On August 30 and 31, a special data playback survey technique, known as the
jailbar search, was executed which sampled approximately every three camera
lines out of 330. The SSI/NIMS high resolution observation (95 percent
confidence) was located in Frames 11, 12 13, 14, and 21.
15. On September 2, real-time commands were sent to switch the downlink data
rate from 40 to 10 bps in accordance with the planned EJ-3 sequence activities.
16. The AC/DC bus imbalance measurements have not exhibited significant change
(greater than 25 DN) throughout this period. The AC measurement reads 17 DN
(3.9 volts). The DC measurement reads 156 DN (18.4 volts). These measurements
are consistent with the model developed by the AC/DC special anomaly team.
17. The Spacecraft status as of September 2, 1993, is as follows:
a) System Power Margin - 56 watts
b) Spin Configuration - All-Spin
c) Spin Rate/Sensor - 2.89rpm/Star Scanner
d) Spacecraft Attitude is approximately 12 degrees
off-sun (lagging) and 1 degree off-earth (Leading)
e) Downlink telemetry rate/antenna- 10bps(coded)/LGA-1
f) General Thermal Control - all temperatures within
acceptable range
g) RPM Tank Pressures - all within acceptable range
h) Orbiter Science- Instruments powered on are the PWS,
EUV, UVS, EPD, MAG, HIC, and DDS
i) Probe/RRH - powered off, temperatures within
acceptable range
j) CMD Loss Timer Setting - 264 hours
Time To Initiation - 259 hours
UPLINK GENERATION/COMMAND REVIEW AND APPROVAL:
1. The Reserve Box Sequence (RBS) for the playback of the high resolution Ida
observation was approved for transmission by the Project on September 2, 1993.
Data playback will begin on September 3 and continue through September 22, 1993.
GDS (GROUND DATA SYSTEMS):
1. Galileo Ground Data System (GDS) test of MGDS V18.1.1 Command (CMD) was
conducted on August 28, 1993 with the Galileo Testbed. This was the first GDS
test using V18.1.1 CMD and the Galileo Testbed. The Testbed command workstation
successfully translated files into GCMDs. Two Testbed command flows were
successfully tested: 1) direct transition of GCMDs into the CDS (via the CDS
LTS support equipment), and 2) transition of GCMDs to the CDS LTS 9 track tape
for storage. Both Command and MSS generated GCMDs were used during the test.
Two configuration problems were identified during the test and will be corrected
prior to the next GDS test.
TRAJECTORY
As of noon Thursday, September 2, 1993, the Galileo Spacecraft trajectory
status is as follows:
Distance from Earth 550,077,100 km (3.68 AU)
Distance from Sun 446,319,300 km (2.99 AU)
Heliocentric Speed 63,500 km per hour
Distance from Jupiter 390,525,700 km
Round Trip Light Time 61 minutes, 14 seconds
SPECIAL TOPIC
1. As of September 2, 1993, a total of 72331 real-time commands have been
transmitted to Galileo since Launch. Of these, 65563 were initiated in the
sequence design process and 6768 initiated in the real-time command process.
In the past week, 39 real time commands were transmitted; nine were initiated
in the sequence design process and 30 initiated in the real-time command
process. Major command activities included commands to reposition the scan
platform, turn the gyros on, turn the Bay B replacement heater on and off, turn
the accelerometers on, clear the AACS fault protection status bits, perform
dual-spin/all-spin mode transitions, reset the command loss timer, switch to 40
bps, and switch to 10 bps.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Nobody notices when things
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | go right.
|_____|/ |_|/ |_____|/ |
|
| 560.889 | Biased Media | VERGA::KLAES | Quo vadimus? | Fri Sep 03 1993 16:33 | 6 |
| It is a shame that the media did not bother to cover only the
second planetoid flyby in history with the same effort that they
did with the Mars Observer failure.
Larry
|
| 560.890 | The Galileo/Voyager/Shoemaker-Levy connection | SKYLAB::FISHER | Carp Diem : Fish the Day | Fri Sep 03 1993 17:05 | 56 |
| Article 21987 of sci.space:
From: gam@csi.jpl.nasa.gov (Glenn Macala)
Newsgroups: sci.space,sci.astro,alt.sci.planetary
Subject: Re: JPL Mission Updates - 09/01/93
Date: 3 Sep 1993 16:39:34 GMT
Organization: Jet Propulsion Laboratory
Lines: 39
Distribution: world
Message-ID: <267s06$qfj@csi.jpl.nasa.gov>
References: <2SEP199322253174@kelvin.jpl.nasa.gov>
<1993Sep3.064528.10370@sfu.ca> <1993Sep3.071939.11913@ee.ubc.ca>
NNTP-Posting-Host: keaggy.jpl.nasa.gov
Xref: jac.nuo.dec.com sci.space:21987 sci.astro:15507 alt.sci.planetary:2185
In article <1993Sep3.071939.11913@ee.ubc.ca>, davem@ee.ubc.ca (Dave Michelson)
writes:
|> In article <1993Sep3.064528.10370@sfu.ca> Leigh Palmer <palmer@sfu.ca> writes:
|> >
|> >>Rumour has it that Voyager may be able to image the shoemaker
|> >>Levy impact string at Jupiter.
|> >>
|> >>Anyone know more?
|> >
|> >I don't think Voyager 1 is capable of "imaging" the impact.
|> >It's too far away from Jupiter to take exciting pictures.
|> >What I hope is that it can detect the impact.
|>
The following was garnered from informal conversations at JPL:
Predictions are that Shoemaker-Levy will impact Jupiter on the side of the
planet not facing the Earth. However, the Galileo spacecraft will be in
a position to possibly see it on the limb of the planet. The plan would be to
schedule a series of photos around the predicted time of impact. However,
since Galileo's high gain is still useless, transmission of all the photos back
to Earth would be too excessive a demand on DSN resources.
In comes the Voyager connection. The camera would be turned on around the
predicted impact time. The S/C would begin a long exposure along with a very
slow turn. This would cause Jupiter to appear as a streak in the image. When
the comet hits Jupiter, the streak would brighten up. Since there are many
pieces of the comet, many brightenings may be seen.
The Voyager picture would then be used, among other things, to predict which
of the Galileo photos stored on the tape recorder would have seen the impact.
Only this small set would need to be transmitted to Earth.
As stated earlier, this info is not taken from official JPL plans, but from
talking to people working the problem. There may be problems with turn on the
Voyager cameras. I've heard people say no one on the current ops team knows
how to run them anymore.
|
| 560.891 | | DCOPST::TONYSC::SCOLARO | One Way out | Fri Sep 03 1993 18:54 | 23 |
| re .889
Sorry,
1) I frankly feel that NASA doesn't want any more coverage of Galileo right
now, that stuck HGA is not something I'd want to advertise.
2) Complaining about lack of news coverage is inapropriate at this point. NASA
doesn't even know the amount of scuccess they had because of 1)
3) It is human nature to be more interested in failure than success.
The press' actions in the case of these two occurances are, in my opinion,
natural, understandable and possibly unavoidable. Also, FWIW, press coverage of
the two events is probably right in keeping with the amount of coverage I want.
I have been hanging on hearing something from MO for 10 days, I would rather
hear that it was still dumb, if not <substitute appropriate word for lack of
time sence> than not hear anything.
I have plenty of time to hear about the encounter at IDA and see the pictures in
Astronomy Magazine.
Tony
|
| 560.892 | | DCOPST::TONYSC::SCOLARO | One Way out | Fri Sep 03 1993 18:57 | 9 |
| Also, the scal is totally different.
The Galileo is a minor portion of the mission, not in the origial mission plan.
With MO, it is nearly a total loss.
To assume equal coverage would be required is not logical at all.
Tony
|
| 560.893 | RE 560.892 | VERGA::KLAES | Quo vadimus? | Fri Sep 03 1993 20:07 | 7 |
| I agree with your comments, but I still feel that more should
be made about a planetoid flyby, especially since we aren't doing
them on a regular basis yet. Maybe I just grew up in the space
exploration heyday when everything seemed wonderful.
Larry
|
| 560.894 | Galileo Update -- 09/03/93 | 8817::J_BUTLER | E pur, si muove... | Mon Sep 06 1993 13:27 | 28 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 3, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 10 bps (bits/second).
Yesterday, real-time commands were sent to switch the downlink data rate
from 40 bps to 10 bps. Tracking was scheduled over DSS-43 (Canberra 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, September 3, 1993, a Reserve Box sequence was uplinked which will
control the playback of the Ida high resolution image data starting this
evening and continuing through September 22, 1993. Real-time commands
are scheduled to switch the downlink data rate to 40 bps. Tracking is
scheduled DSS-63, DSS-14 and DSS-43 (Canberra 70 meter antenna).
Over the weekend, playback of the Ida high resolution image data is
scheduled to continue. Tracking is scheduled over DSS-43, DSS-63 and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Nobody notices when things
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | go right.
|_____|/ |_|/ |_____|/ |
|
| 560.895 | Galileo Update -- 09/07/93 | CXDOCS::J_BUTLER | E pur, si muove... | Tue Sep 07 1993 21:04 | 33 |
|
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 7, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Over the weekend, playback of the Ida high resolution image data
continued. Real-time commands were sent to replay image data loss due to a
DSN (Deep Space Network) ground station transformer problem. Tracking was
scheduled over DSS-43 (Canberra 70 meter antenna), DSS-63 (Madrid 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, September 7, 1993, playback of the Ida high resolution image data
is continuing. Real-time commands were sent to replay image data loss due
to a DSN ground station transformer problem. Real-time commands are also
scheduled to switch the downlink data rate to 10 bps and then back to 40 bps.
A routine RPM (Retro-Propulsion Module) thruster flushing maintenance activity
is scheduled. DACs (Delayed Action Commands) are scheduled to transition the
spacecraft to the dual-spin mode for RPM maintenance activity and then return
to all-spin mode. Tracking is scheduled DSS-63 and DSS-14.
Tomorrow, playback of the Ida high resolution image data is scheduled to
continue. Tracking is scheduled over DSS-14 and DSS-63.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Nobody notices when things
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | go right.
|_____|/ |_|/ |_____|/ |
|
| 560.896 | Update - September 8 | VERGA::KLAES | Quo vadimus? | Thu Sep 16 1993 02:52 | 41 |
| Article: 4598
Newsgroups: sci.space.news
From: baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke)
Subject: Galileo Update - 09/08/93
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Wed, 8 Sep 1993 17:53:00 GMT
Forwarded from Bill O'Neil, Galileo Project Manager
GALILEO STATUS REPORT
September 8, 1993
The Galileo Spacecraft is operating normally in the all-spin mode and
is transmitting coded telemetry at 40 bps (bits/second).
Yesterday, playback of the Ida high resolution image data continued.
Real-time commands were sent to replay image data loss due to a DSN (Deep
Space Network) ground station transformer problem. Real-time commands were
also sent to switch the downlink data rate to 10 bps and then back to 40 bps.
A routine RPM (Retro-Propulsion Module) thruster flushing maintenance activity
was performed. DACs (Delayed Action Commands) executed which transitioned the
spacecraft to the dual-spin mode for the RPM maintenance activity and then
return to all-spin mode. Tracking was scheduled DSS-63 (Madrid 70 meter
antenna) and DSS-14 (Goldstone 70 meter antenna).
Today, September 8, 1993, playback of the Ida high resolution image data
is continuing. Tracking is scheduled over DSS-14 and DSS-63.
Tomorrow, playback of the Ida high resolution image data is scheduled to
continue. Real-time commands are also scheduled to switch the downlink data
rate to 10 bps and then back to 40 bps. Tracking is scheduled over DSS-63
and DSS-14.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Nobody notices when things
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | go right.
|_____|/ |_|/ |_____|/ |
|
| 560.897 | Ida image available | VERGA::KLAES | Quo vadimus? | Wed Sep 22 1993 17:36 | 76 |
| From: US1RMC::"newsdesk@jplpost.jpl.nasa.gov" "JPL Public Information"
22-SEP-1993 13:20:57.35
To: sci-space-news@uunet.uu.net
CC:
Subj: First Galileo Ida GIF image available
A GIF version of the first released image of the asteroid Ida
taken by the Galileo spacecraft is now available at the JPL Info
public access computer site.
The file, IDA.GIF, may be obtained by the following methods:
-- Over Internet by anonymous ftp to jplinfo.jpl.nasa.gov
(137.78.104.2), in directory /news.
-- By dialup modem to +1 (818) 354-1333, library NEWS.
Shareware/freeware software that allows viewing of the image on
most computer types is also available at the JPL Info site in the
directory /software.
For questions, contact newsdesk@jplpost.jpl.nasa.gov by Internet
electronic mail.
-----------------
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CA 91109. PHONE (818) 354-5011
PHOTO CAPTION P-42964
GLL/IDA1
September 22, 1993
This view of the asteroid 243 Ida is a mosaic of five image
frames acquired by the Galileo spacecraft's solid-state imaging
system at ranges of 3,057 to 3,821 kilometers (1,900 to 2,375
miles) on August 28, 1993, about 3-1/2 minutes before the
spacecraft made its close approach to the asteroid. Galileo flew
about 2,400 kilometers (1,500 miles) from Ida at a relative
velocity of 12.4 km/sec (28,000 mph). Asteroid and spacecraft
were 441 million kilometers (274 million miles) from the Sun.
Ida is the second asteroid ever encountered by a spacecraft. It
appears to be about 52 kilometers (32 miles) in length, more than
twice as large as Gaspra, the first asteroid observed by Galileo
in October 1991. Ida is an irregularly shaped asteroid placed by
scientists in the S class (believed to be like stony or stony-
iron meteorites). It is a member of the Koronis family, presumed
fragments left from the breakup of a precursor asteroid in a
catastrophic collision.
This view shows numerous craters, including many degraded craters
larger than any seen on Gaspra. The extensive cratering seems to
dispel theories about Ida's surface being geologically youthful.
This view also seems to rule out the idea that Ida is a double
body. The south pole is believed to be in the dark side near the
middle of the asteroid.
The camera's clear filter was used to produce this extremely
sharp picture. Spatial resolution is 31 to 38 meters (roughly
100 feet) per pixel. A 30-frame mosaic was taken to assure
capturing Ida; its position was somewhat uncertain before the
Galileo encounter. Galileo shuttered and recorded a total of 150
images in order to capture Ida 21 different times during a five-
hour period (about one rotation of the asteroid). Color filters
were used at many of these times to allow reconstruction of color
images. Playback to Earth of the remaining images is planned for
April through June 1994.
The Galileo project, whose primary mission is the exploration of
the Jupiter system in 1995-97, is managed for NASA's Office of
Space Science by the Jet Propulsion Laboratory.
|
| 560.898 | Ida image in public area | VERGA::KLAES | Quo vadimus? | Wed Sep 22 1993 17:56 | 9 |
| Ida image available at:
PRAGMA::PUBLIC:[NASA]GAL_IDA_1.*
In some ways Ida is more impressive-looking than Gaspra, but of
course Ida is almost 20 miles larger.
Larry
|
| 560.899 | More on the HGA Problem | CXDOCS::J_BUTLER | E pur, si muove... | Wed Sep 22 1993 19:05 | 60 |
| Newsgroups: sci.space
From: gary@ke4zv.atl.ga.us (Gary Coffman)
Subject: Re: Can neural nets help Galileo?
Organization: Destructive Testing Systems
Date: Wed, 22 Sep 1993 15:26:07 GMT
In article <1993Sep17.154650.1@joyl.joensuu.fi> hounsell@joyl.joensuu.fi writes:
>Subject: Can the damaged high gain antenna of the Galileo probe be used?
>
> Please forgive my ignorance in these areas. I freely admit to having
>very little knowledge in these areas, and we know how dangerous a little
>knowledge can be. Here is my question and I would appreciate anyone
>with the knowledge as to why this will not work.
>
> Can a neural network be used to get information back from
> Galileo probe using the damaged high gained antenna?
>
> Let me explain my idea:
> Do with Galileo what NASA is doing with Hubble but use
> a neural network because we don't know what the exact shape of
> the high gain antenna (HGA) is. If the HGA is even able to
> transmit some energy towards Earth. Would NASA be able to get
> more information back than through the low gain antenna (LGA)?
> My experience is a little with optics and none with antennae
> but with each bit transmitted shouldn't we get a bad case of
> ghosting as the transmitted pulse bounces around the unfurled
> part of the antenna. If even 10% of the of the energy of the
> transmission pulse gets directed towards Earth would this not
> allow more information than is possible from the LGA. NASA could
> send known patterns so a neural network to learn how the ghosting
> of the antenna works. Also the LGA could be used to send error
> correction code if the LGA can transmit on a different frequency
> than the HGA.
>
> Since NASA is not trying this can somebody give me a solid
>scientific/engineering reason why this can not work? Please don't flame
>my ignorance, we all have to learn sometime.
NASA has experimented to see if the HGA could give useful gain in it's
present condition. The conclusion was that it could not. Remember that
Hubble isn't useful for the weak sources it was intended to be able to
image because it's malformed mirror limits the gain of the system.
Post-processing can use Hubble with bright sources because the distortion
is understood and can be corrected, but there's a minium level of signal
required to be able to do post processing. With the HGA that's also a
function of residual usable gain, and there isn't enough. Most of the
transmitted energy goes into sidelobes that aren't pointing at Earth,
or any other common point. The shape error isn't on the order of a human
hair, it's really grossly malformed with at least one rib stuck in the
furled position. If the energy doesn't reach Earth, no amount of post-
processing helps. The LGA is in effect the high gain array now on Galileo.
The HGA is just a twisted mass of junk.
Gary
--
Gary Coffman KE4ZV |"If 10% is good enough | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | for Jesus, it's good | uunet!rsiatl!ke4zv!gary
534 Shannon Way | enough for Uncle Sam."| emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244 | -Ray Stevens |
|
| 560.900 | | AUSSIE::GARSON | nouveau pauvre | Fri Sep 24 1993 03:12 | 11 |
| 560.901 | How to convert?? | CSC32::HADDOCK | Don't Tell My Achy-Breaky Back | Fri Sep 24 1993 16:01 | 9 |
|
Can anyone give me some pointer on how to convert the .gif file.
I copied it over from PRAGME::PUBLIC:[NASA] and tried to run it
throught the XV converter, but I'm getting "not in a recognized
format". I tried copying it both with $COPY (gave me fixed-length
512 byte record file) and $EXCHANGE COPY (gave me variable-length
maximum 512 byte record). Is there any other coverter for VMS
that would be better?
fred()
|
| 560.902 | looks like nojoy on the file | CSC32::HADDOCK | Don't Tell My Achy-Breaky Back | Fri Sep 24 1993 16:45 | 6 |
|
I copied PRAGMA:PUBLIC:[NASA]MGN_VOLCANO_TAIL.GIF and ran it throught
the XV converter ok, I also copied PRAGMA:TOOLKIT:XGIF.exe and it
gave me the same sort of format error on GAL_IDA_1.GIF. Looks
like there may be something wrong with the GAL_IDA_1.GIF file.
fred();
|
| 560.903 | | AUSSIE::GARSON | Hotel Garson: No Vacancies | Sun Sep 26 1993 06:12 | 19 |
| re .901
> Can anyone give me some pointer on how to convert the .gif file.
You're not supposed to be converting it.
XV works just fine for me. I have V2.21 (REV: 4/29/92). You can grab
that from AUSSIE::SYS$PUBLIC:[IMAGE_STUFF]XV.EXE if you don't have it.
>I tried copying it both with $COPY (gave me fixed-length 512 byte record file)
COPY is goodness. FIX 512 is an acceptable result.
>I also copied PRAGMA:TOOLKIT:XGIF.exe and it gave me the same sort of format
>error on GAL_IDA_1.GIF.
'Tis true. There are two kinds of GIF files. GIF87 and GIF89.
GAL_IDA_1.GIF is a GIF89 file and my copy of XGIF at least cannot
handle that.
|
| 560.904 | | CSC32::HADDOCK | Don't Tell My Achy-Breaky Back | Tue Sep 28 1993 14:38 | 5 |
| re -1
Got the new XV. Looks great. Looks like that is what the problem
was. Thanks.
fred();
|
| 560.905 | Ida GIF (JPG) image | VERGA::KLAES | Quo vadimus? | Thu Sep 30 1993 19:11 | 104 |
| Article: 43961
Newsgroups: sci.astro
From: stooke@sscl.uwo.ca
Subject: further remarks on Ida
Organization: Social Science Computing Laboratory
Date: Tue, 28 Sep 1993 20:58:47 GMT
Sender: news@julian.uwo.ca (USENET News System)
A few comments on the Ida image - since others have appeared here.
First, as Bill Higgins pointed out, the actual resolution of the original
image is twice as good as that of the GIF, so we will see more in it
eventually.
Second, part of Ida is covered by a higher resolution frame, about 24 m
per pixel compared with this 31-35 m resolution image, so there we will
see even more.
Third, the object is being viewed from approximately 30 degrees south
of the equator (which parallels the limb). THe terminator is about 60 deg.
south (very rough estimate from a preprint by Binzel et al. on its way
to Icarus). The south pole is in darkness near the centre of the length
of the terminator. Rotation is probably retrograde, so the earlier approach
views will look into the big 'kazoo' crater at the left end, and will
also show far more of the north side than we can see here.
Now for the features. There appear to me to be a few small crater chains,
notably near the top centre and at both the extreme right and extreme left.
It is not easy to be sure that they are more than chance clusters
of random impacts. Gaspra had a few very obvious grooves, this does not.
Other views may clarify this. There are more obvious degraded craters
with overlapping impacts than were obvious on Gaspra, but this may not
be much more than a resolution effect. The few large craters on Gaspra
were not well seen in the highest resolution view. Gaspra looked a
bit smoother, but that might just be a resolution effect.
It is impossible to draw useful conclusions about overall shape until the
other pictures trickle down. Incidentally, an upcoming issue of Icarus
will be devoted to Gaspra papers, and some great stuff on shape modelling
and mapping will be presented by those wizards at Cornell. Ground-based
modelling suggests possible albedo variations (a north-south split, not
very strong but interesting).
Bill suggested something about crater rays in the upper right. I am
sure that these radial marks are topographic, not albedo.
=============
Just to be sure, I am not privy to the discussions of the camera team
and have only looked at the GIF image. This is where we can all play
instant science for once.
Phil Stooke
Article: 43981
Newsgroups: sci.astro
From: apryan@vax1.tcd.ie
Subject: Re: further remarks on Ida
Sender: usenet@news.tcd.ie (USENET News System)
Organization: Trinity College Dublin
Date: Wed, 29 Sep 1993 02:47:35 GMT
In article <1993Sep28.165847.1@sscl.uwo.ca>, stooke@sscl.uwo.ca writes:
> A few comments on the Ida image - since others have appeared here.
>
> First, as Bill Higgins pointed out, the actual resolution of the original
> image is twice as good as that of the GIF, so we will see more in it
> eventually.
>
> Second, part of Ida is covered by a higher resolution frame, about 24 m
> per pixel compared with this 31-35 m resolution image, so there we will
> see even more.
Although this GIF was made from data that may have your 31-35m
resolution, it clearly shows the 52km long Ida at about 600 pixels
long so 1 pixexl approx. 90m, not 30m!
Also, it is a scan of a photographic print. Apart from errors in the scanner
(and taking lessons from CCDs, these must reduce the integrity of 256
grey levels to who knows, perhaps 100?), displaying more than 100 grey
scales on a print is not even physically possible I believe. I remember
reading that whereas film itself can perhaps record 100,000 grey levels,
a print can only do about 100. Anyway, the human eye is said to be only able
to distinguish 60ish grey scales at once, however, by manipulating the
image we could see 60ish levels of gray in the brightly sunlit areas
and 60 completely different (lower) levels of grey near the dimmer
terminator.
So, adding all the low-res (both pixels and grey scales) problems you
can see that there's a lot left for a real digital image to show us.
And that's on these images let alone the higher res stillbeing
sent back!
Has anyone asked NASA folk when they'll release digital version of this
mosaic?
-Tony Ryan, ASTRONOMY & SPACE magazine published by:
Astronomy Ireland, P.O.Box 2888, Dublin 1, Ireland. VISA/MC accepted.
(ONE OF WORLD'S LARGEST ASTRO. SOC. per capita - email re any larger! 0.043%)
^
growing fast! up another 5 notches by early July 1993!-----^
Tel: 0 8 9 1 - 8 8 - 1 9 - 5 0 for U.K. Hotline (new message Mondays)
(dial 1550-111-442 in Republic of Ireland)
|
| 560.906 | Galileo Update -- 10/04/93 | CXDOCS::J_BUTLER | E pur, si muove... | Mon Oct 11 1993 13:34 | 39 |
|
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
October 4, 1993
The Galileo spacecraft is beginning a five-day trajectory
correction maneuver to aim it directly for Jupiter for the first
time in the flight. The maneuver will entail a total of about
10,000 pulses from the lateral thrusters to change the velocity
by 38.6 meters per second (about 86 miles per hour), partly
increasing the speed and partly changing the direction.
The maneuver is being performed in five portions, one each
day today through Friday, October 8. The daily sessions are
commanded from the Deep Space Network station near Canberra,
Australia, and are scheduled to take place over the stations at
Goldstone, Calif., and at Canberra.
Galileo is almost 479 million kilometers (297 million miles)
from the Sun, and its speed in orbit is 16.5 kilometers per
second (nearly 37,000 mph). The spacecraft has gone about 55
million kilometers since its encounter with asteroid Ida; there
are still 663 million to go to reach Jupiter. The spacecraft and
Earth are more than 616 million kilometers (383 million miles)
apart.
The spacecraft is in dual-spin mode, in which part of the
craft spins at 3.15 rpm and part is fixed in relation to space;
it is transmitting coded telemetry at 10 bits per second over the
low-gain antenna. Galileo's health and performance are
excellent.
|
| 560.907 | Galileo Detects Magnetic Field Around Asteroid Ida | CXDOCS::J_BUTLER | E pur, si muove... | Tue Oct 26 1993 08:54 | 63 |
|
Paula Cleggett-Haleim
Headquarters, Washington, D.C. October 22, 1993
(Phone: 202/358-0883)
James H. Wilson
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
RELEASE: 93-193
GALILEO DETECTS MAGNETIC FIELD AROUND ASTEROID IDA
NASA's Galileo spacecraft detected changes in the interplanetary
magnetic field as it passed the asteroid Ida on Aug. 28, scientists reported
today.
Dr. Margaret Kivelson, Principal Investigator of the Galileo
magnetometer and a physicist at the University of California at Los Angeles,
reported that the instrument measured several field rotations as it had 2 years
ago while flying by the asteroid Gaspra.
Magnetic field rotations, in which the direction of the magnetic field
swings or shifts, are commonly observed in interplanetary space.
"The team believes these observed rotations were produced by the
interaction of the solar wind with Ida," Kivelson said. However, several
interactions could cause the field to rotate. Thus, the observations do not
necessarily show that the asteroid has a magnetic field.
Kivelson said that in the case of the smaller asteroid Gaspra, the
measurements provided indirect evidence of an asteroid magnetic field for the
first time.
Before Galileo's Gaspra encounter in October 1991, small asteroids
generally were not expected to possess their own magnetic fields, though some
meteorites -- believed to be fragments of asteroids -- have measurable fields.
Analysis of data from Galileo's Ida flyby has not progressed far enough
for Kivelson's team to speculate on whether this asteroid also is magnetized,
she said.
Kivelson presented the results at the annual meeting of the Division of
Planetary Sciences of the American Astronomical Society in Boulder, Colo.
Galileo's magnetometer and other instruments have been collecting data
on the solar wind and the space environment since shortly after the
spacecraft's launch in October 1989.
Ida represented the fifth encounter for Galileo, said Project Scientist
Dr. Torrence Johnson. The spacecraft flew once by Venus and twice by the
Earth and the moon for gravity assists and scientific observation, in addition
to encountering the asteroids Gaspra and Ida.
Galileo is now on its way to Jupiter where in 1995, it will direct its
instrumented probe into the atmosphere and then go into orbit to conduct a 2-
year survey of Jupiter, its satellites and its magnetosphere.
Project Galileo was developed and is managed for NASA's Office of Space
Science, Headquarters, Washington, D.C., by the Jet Propulsion Laboratory,
Pasadena, Calif.
|
| 560.908 | Moon images may suffer | VERGA::KLAES | Quo vadimus? | Tue Nov 16 1993 20:21 | 28 |
| Article: 2728
Newsgroups: alt.sci.planetary
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: GALILEO antenna problems?
Date: Sat, 13 Nov 1993 06:45:55 GMT
Organization: U of Toronto Zoology
I wrote:
>...The flybys of Jupiter's moons should not suffer much, because they are
>spread out enough that the pictures can be stored on the tape recorder and
>played back in between flybys.
Correction: my spies tell me that this isn't quite true. JPL always
planned to make some use of the tape recorder for the flybys, because
even the big antenna's data rate wasn't enough for the close parts
with the camera snapping pictures madly... but the flyby plans were
rather fancy, with more than one tape-recorder-full of data returned
from each. The new plans are necessarily rather simpler, with fewer
images, less color, and lower resolution for the full-coverage mosaics.
They will also lose some image quality with the drastic data compression.
This is still a rather happier situation than the one the atmosphere
people are facing.
--
Study it forever and you'll still | Henry Spencer @ U of Toronto Zoology
wonder. Fly it once and you'll know. | henry@zoo.toronto.edu utzoo!henry
|
| 560.909 | How to return data with the LGA | VERGA::KLAES | Quo vadimus? | Wed Nov 24 1993 16:16 | 104 |
| Article: 78266
From: steven@spri.Levels.UniSA.Edu.Au (Steven Pietrobon)
Newsgroups: sci.space,alt.sci.planetary
Subject: Re: Galileo Antenna Problems Questions
Date: 23 Nov 1993 22:30:28 GMT
Organization: Co-operative Research Centre for Sensor Signal and Information
Processing.
Sender: steven@igor (Steven Pietrobon)
Justin D. Paola of the University of Arizona
(paola@dialipc-gw.ece.arizona.edu) wrote on 23 Nov 1993 19:40:45 GMT
asking some questions about Galileo's low gain mission and how it is
to be achieved.
You can find some information in
K.-M. Cheung, D. Divsalar, S. Dolinar, I. Onyszchuk, F. Pollara, and
L. Swanson, "Changing the coding system on a spacecraft in flight,"
IEEE International Symposium on Information Theory, San Antonio, TX,
p. 381, 17-22 January 1993.
I asked the authors for more detailed information than given in the
one page that was published, but none was forthcoming (I am interested
in the error control coding that is going to be used). This is what
they said on the image compression algorithm.
"Until now, data compression algorithms for deep-space have been
limited to lossless compression, and thus to about 3.6 bits/pixel,
while slightly lossy algorithms like the proposed Joint Photographic
Experts Group (JPEG) standard show almost no visual degradation at
less than 1 bit/pixel, compared to our original 8 bits/pixel. Because
the communications rate with the low gain antenna is so low, many of
the planned images would not be sent at all, and so the small
distortions introduced by data compression are now much more
attractive to scientists.
A JPEG standard 8x8 Discrete Cosine Transform (DCT) is not possible
within our constrained memory and computer resources, but we intend to
implement a similar multiplication-free integer transform, the Integer
Cosine Transform (ICT), which can compress a typical planetary image
10:1 with an RMS error of 1 (out of 256) gray level, (peak SNR 48 dB),
or 20:1 with an RMS error of 2, with memory requirements of 4K bytes
for code and 7K bytes for buffer, using 32 adds and 12 shifts for each
8-point DCT. This algorithm will be used on Galileo's images if a
low-gain mission is required."
As Justin pointed out, the information bit rate from Galileo will be
100 bit/s, which when combined with image compression gives an
effective bit rate of 1 kbit/s.
--
Steven S. Pietrobon, Australian Space Centre for Signal Processing
Signal Processing Research Institute, University of South Australia
The Levels, SA 5095, Australia. steven@spri.levels.unisa.edu.au
Article: 78272
Newsgroups: sci.space,alt.sci.planetary
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Galileo Antenna Problems Questions
Date: Tue, 23 Nov 1993 22:20:09 GMT
Organization: U of Toronto Zoology
In article <2ctovt$7qn@organpipe.uug.arizona.edu>
paola@dialipc-gw.ece.arizona.edu (Justin D. Paola) writes:
>8) Another thing I haven't heard mentioned in the slightest is the use
> of Galileo beyond the 23 month mission. Again, I'm assuming that
> the thing won't just be abandoned at that point...
Galileo is a little different from something like Magellan. The
"primary mission" for Magellan was defined somewhat arbitrarily, and
there was every intention, barring massive equipment failure, of
continuing the mission for a considerably longer period to get more data.
Galileo is different. It will be burning fuel steadily, setting up
for one moon encounter after another. The end of its primary mission
was defined, as I understand it, by the time when (under some fairly
conservative assumptions) its tanks will be dry and it will lose
attitude control. When its tanks go dry, its mission is *over*.
In practice, fuel consumption is running better than predicted, and
some modest extended mission will probably be possible. But I'd guess
we're talking about a few months at most, not years and years. There
was some discussion of possible grand finales, as I recall, including
a proposal for a kamikaze dive to an Io impact (Io is deep enough in
Jupiter's Van Allen belts that Galileo will risk visiting it only
once, to minimize radiation damage, and a second look -- especially a
good close one :-) -- would be welcome). The antenna situation is
clearly going to constrain such ideas considerably; notably, the Io
dive isn't going to be possible without real-time picture transmission.
One radical thought does occur to me, though... Galileo is
spin-stabilized, so its attitude will change only slowly once it runs
out of fuel, and since the high-gain antenna is useless there is no
obvious need to keep the whole craft pointed in one particular
direction. Could Galileo fly a lengthy extended mission without
attitude control? With no maneuvering fuel it isn't going to do any
more flybys, but I'd think one could still do a good fields-and-particles
mission. There may be other subsystems, like thermal control, that would
be fouled up by loss of attitude control, but I don't immediately know
how bad it would be.
--
Belief is no substitute | Henry Spencer @ U of Toronto Zoology
for arithmetic. | henry@zoo.toronto.edu utzoo!henry
|
| 560.910 | | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Wed Nov 24 1993 16:32 | 4 |
| I would think that the obvious "extended mission" would be the
trickling back of as much of the data as possible. Keeping the
recorders playing back and the LGA transmitter going as long as
possible.
|
| 560.911 | Galileo HGA Information | CXDOCS::J_BUTLER | E pur, si muove... | Sat Nov 27 1993 10:10 | 78 |
|
From USENET:
...
Recently I've been reading alot about Galileo's antenna problems
and how the mission will proceed with the low gain antenna.
So far I've seen alot of "final" numbers (ie, 70% of this part of
the original mission and 80% of that part will be completed), but very
little detail in any of the literature concerning how the problem
will be tackled. It's interesting to note that before they even tried
unfurling the antenna someone at JPL (I forget who, this was in
a back issue of Astronomy) said if the high gain antenna didn't deploy
they'd be dead in the water. Its funny that now that it hasn't, they seem
to be saying they can still do most of what they wanted.
Anyway, this is what I know of the problem (and have gathered from several
sources):
The high gain antenna is useless.
The low gain antenna is capable of 10 bits/sec at the distance of
Jupiter with the current Deep Space Network equipment.
The tape drive on the spacecraft is on the order of a gigabit (?).
Now, one of the quotes I have seen goes something like this:
"With image compression algorithms and improvements in the Deep Space
Network transmission rates of 100 bps will be achieved".
This is a very vague statement in that 1) It doesn't separate the raw
bit rate capability of the LGA-DSN link (ie, how much over 10 bps will that
alone be improved) from the compression technique,
and 2) It doesn't indicate what kind of image compression is being considered.
My particular interest in this problem is the image compression aspect.
It seems to me that lossless compression could be used to compress the
most important images (ie, high-resolution satellite imagery) and achieve
25 to 50% compression. The atmospheric images (ie, for creating Jupiter
waether movies, etc) could be compressed using JPEG or even MPEG where
compression rates of 10:1 or even 100:1 are possible. I'm assuming
that the computer on board Galileo is capable of these kinds of algorithms.
My questions to anyone out there (JPL people??) are:
1) What is the capacity of the tape drive?
2) What is the computing capability of the Galileo computer(s)?
3) What are the current plans for image compression?
4) What will the nominal bit rate be (ie, the LGA-DSN link) without
compression?
5) Are there going to be different algorithms or lossy compression
quality levels for different types of imagery?
6) How often can the DSN be used for data collection from Galileo?
I'm assuming that one major limiting factor will be the DSN's
availability - ie, it can't be used 24 hours a day 365 days a year
in order to collect maximum data.
7) How much noise is inherent in the downlink? I've been examining
the Galileo cruise CD's from NSSDC and there seems to be a great
deal of errors. Presumably more noise will be introduced in the
process because the low gain antenna will be pushed to its
maximum usage and signal to noise ratio will be low.
8) Another thing I haven't heard mentioned in the slightest is the use
of Galileo beyond the 23 month mission. Again, I'm assuming that
the thing won't just be abandoned at that point, especially with its
antenna problems hampering data collection. Someone posted on the
net a week or so ago that the antenna problems will cause the
satellite mapping to lose some resolution. If JPL chooses this route,
it seems this is a grave
mistake since who knows how many more years it will be before another
spacecraft makes it out to Jupiter again. Maximum resolution ought
to be obtained even if it means doing it over 4 or 5 years and using
lossy compression (although it would be nice to avoid that as well).
The question is, does Galileo have enough in its thrusters to allow
for significant continued operations? Presumably JPL has already worked
out the details of the extended mission. Any details on this?
Justin Paola
University of Arizona
Department of Electrical and Computer Engineering
|
| 560.912 | Commentary and Replies re: 560.911 | CXDOCS::J_BUTLER | E pur, si muove... | Sat Nov 27 1993 10:18 | 372 |
|
A series of replies and comments re: 560.911 from USENET:
...
Justin D. Paola of the University of Arizona (paola@dialipc-gw.ece.arizona.edu)
wrote on 23 Nov 1993 19:40:45 GMT asking some questions about Galileo's low
gain mission and how it is to be achieved.
You can find some information in
K.-M. Cheung, D. Divsalar, S. Dolinar, I. Onyszchuk, F. Pollara, and L. Swanson,
"Changing the coding system on a spacecraft in flight," IEEE International
Symposium on Information Theory, San Antonio, TX, p. 381, 17-22 January 1993.
I asked the authors for more detailed information than given in the one page
that was published, but none was forthcoming (I am interested in the error
control coding that is going to be used). This is what they said on the image
compression algorithm.
"Until now, data compression algorithms for deep-space have been limited to
lossless compression, and thus to about 3.6 bits/pixel, while slightly lossy
algorithms like the proposed Joint Photographic Experts Group (JPEG) standard
show almost no visual degradation at less than 1 bit/pixel, compared to our
original 8 bits/pixel. Because the communications rate with the low gain antenna
is so low, many of the planned images would not be sent at all, and so the small
distortions introduced by data compression are now much more attractive to
scientists.
A JPEG standard 8x8 Discrete Cosine Transform (DCT) is not possible within our
constrained memory and computer resources, but we intend to implement a similar
multiplication-free integer transform, the Integer Cosine Transform (ICT), which
can compress a typical planetary image 10:1 with an RMS error of 1 (out of 256)
gray level, (peak SNR 48 dB), or 20:1 with an RMS error of 2, with memory
requirements of 4K bytes for code and 7K bytes for buffer, using 32 adds and 12
shifts for each 8-point DCT. This algorithm will be used on Galileo's images if a
low-gain mission is required."
As Justin pointed out, the information bit rate from Galileo will be 100 bit/s,
which when combined with image compression gives an effective bit rate of
1 kbit/s.
--
Steven S. Pietrobon, Australian Space Centre for Signal Processing
Signal Processing Research Institute, University of South Australia
The Levels, SA 5095, Australia. steven@spri.levels.unisa.edu.au
In article <2ctovt$7qn@organpipe.uug.arizona.edu> paola@dialipc-gw.ece.arizona.edu (Justin D. Paola) writes:
>8) Another thing I haven't heard mentioned in the slightest is the use
> of Galileo beyond the 23 month mission. Again, I'm assuming that
> the thing won't just be abandoned at that point...
Galileo is a little different from something like Magellan. The "primary
mission" for Magellan was defined somewhat arbitrarily, and there was every
intention, barring massive equipment failure, of continuing the mission for
a considerably longer period to get more data.
Galileo is different. It will be burning fuel steadily, setting up for one
moon encounter after another. The end of its primary mission was defined,
as I understand it, by the time when (under some fairly conservative
assumptions) its tanks will be dry and it will lose attitude control.
When its tanks go dry, its mission is *over*.
In practice, fuel consumption is running better than predicted, and some
modest extended mission will probably be possible. But I'd guess we're
talking about a few months at most, not years and years. There was some
discussion of possible grand finales, as I recall, including a proposal
for a kamikaze dive to an Io impact (Io is deep enough in Jupiter's Van
Allen belts that Galileo will risk visiting it only once, to minimize
radiation damage, and a second look -- especially a good close one :-) --
would be welcome). The antenna situation is clearly going to constrain
such ideas considerably; notably, the Io dive isn't going to be possible
without real-time picture transmission.
One radical thought does occur to me, though... Galileo is spin-stabilized,
so its attitude will change only slowly once it runs out of fuel, and since
the high-gain antenna is useless there is no obvious need to keep the whole
craft pointed in one particular direction. Could Galileo fly a lengthy
extended mission without attitude control? With no maneuvering fuel it
isn't going to do any more flybys, but I'd think one could still do a good
fields-and-particles mission. There may be other subsystems, like thermal
control, that would be fouled up by loss of attitude control, but I don't
immediately know how bad it would be.
--
Belief is no substitute | Henry Spencer @ U of Toronto Zoology
for arithmetic. | henry@zoo.toronto.edu utzoo!henry
Henry.
stodgy, fields and particles missions are always done by Ames.
you know that.
i was of the opinion, if the HGA is shot, forget the imaging mission
except of jupiter, and just fly a fields and particles mission.
Do moon flybys only when they are in particularly advantageous locations.
that way, one can maximise the mission duration, and do the best
with he parts that are left.
pat
--
-----------------------------------------------------------------------------
The greatest mistake you can make in life is to be continually
fearing that you will make one -- Elbert Hubbard.
I wrote:
>In practice, fuel consumption is running better than predicted, and some
>modest extended mission will probably be possible. But I'd guess we're
>talking about a few months at most, not years and years...
I'm told I may have been too pessimistic here. The fuel-consumption
estimates used to define the primary mission length are looking *quite*
conservative, and if care is taken and the luck holds out, it might be
possible to fly a fairly substantial extended mission.
>... Galileo is spin-stabilized...
>... [with no HGA] there is no obvious need to keep the whole
>craft pointed in one particular direction. Could Galileo fly a lengthy
>extended mission without attitude control? ...
>... There may be other subsystems, like thermal
>control, that would be fouled up by loss of attitude control, but I don't
>immediately know how bad it would be.
I'm told that at Jupiter's distance there should be no thermal problems.
The star-sensing system used to monitor attitude contains an implicit
assumption that Galileo's axis isn't pointing too far from the Sun, but
there's a reasonable chance that one could either program around it or
just ignore the problem.
--
Belief is no substitute | Henry Spencer @ U of Toronto Zoology
for arithmetic. | henry@zoo.toronto.edu utzoo!henry
In article <CGyu1M.DB0@zoo.toronto.edu>,
Henry Spencer <henry@zoo.toronto.edu> wrote:
>>8) Another thing I haven't heard mentioned in the slightest is the use
>> of Galileo beyond the 23 month mission. Again, I'm assuming that
>> the thing won't just be abandoned at that point...
>Galileo is different. It will be burning fuel steadily, setting up for one
>moon encounter after another. The end of its primary mission was defined,
>as I understand it, by the time when (under some fairly conservative
>assumptions) its tanks will be dry and it will lose attitude control.
The tanks will not be quite that dry: The mission will end when there
is not enough fuel left for another flyby. There will still be some
fuel left in the tanks for attitude control (at least for a while.)
Compared to orbital maneuvers, attitude control doesn't use
all that much fuel.
>When its tanks go dry, its mission is *over*.
True, but there is some time between the end of the nominal mission
and the tanks running completely dry. That time is of no use at all
to the Satellite Working Group, but an extended mission during this
time would be of use to the Plasma Working Group and the Jupiter
Working Group.
>In practice, fuel consumption is running better than predicted, and some
>modest extended mission will probably be possible. But I'd guess we're
>talking about a few months at most, not years and years.
It depends on how the fuel is used. If fuel consumption remains low,
we might have enough fuel for a few more targeted flybys of moons
(i.e. a few months of dramatic, extended mission.) On the other hand,
the fuel could be used exclusively for attitude control, leaving
Galileo on a fixed orbit. At that rate, an extended mission could
last for years. The Jupiter Working Group could take high resolution
images of Jupiter over a very long period of time; the Plasma
Working Group could do an extended survey of the planet's magnetosphere.
>...The antenna situation is clearly going to constrain
>such ideas considerably; notably, the Io dive isn't going to be possible
>without real-time picture transmission.
I'm not so sure about that: We aren't doing a second Io flyby because
the spacecraft _might_ not survive the radiation. But there is also a
good chance that it would. The odds aren't good enough to bet a
working spacecraft on in the middle of its mission. But at the end
of the mission, when we have very little to loose, an Io flyby
might be worth it. The data could not be sent back in real time, but
if the spacecraft survived, we would have plenty of time to
send the data back. Essentially, it would be a gamble; but at the
end of the mission it might not be a bad bet.
>One radical thought does occur to me, though... Galileo is spin-stabilized,
>so its attitude will change only slowly once it runs out of fuel, and since
>the high-gain antenna is useless there is no obvious need to keep the whole
>craft pointed in one particular direction. Could Galileo fly a lengthy
>extended mission without attitude control?
It depends on what you want to do with it. Some instruments are very
sensitive to pointing (e.g. magnetometers), some are completely
insentsitive (e.g. high energy particle detectors). Most of the
imaging systems do have a limited field of view and have to be
pointed in the right direction. The SSI, the primary imaging
instrument, has a 3 deg. field of view; the NIMS, the IR spectrometer/
camera has a 0.6 x 0.03 deg field. To some extent you could do that
with the scan platform. I'm not sure how far the platform can track,
but the rest of the spacecraft blocks about 75% of its view. You
have to maintain enough attitude control to keep Jupiter (or whatever
you want to image) in that part of the sky. In dual spin mode,
that shouldn't be hard; some fuel would be required but it could
be kept to a very low consumption rate.
Frank Crary
CU Boulder
In article <2ctovt$7qn@organpipe.uug.arizona.edu>,
Justin D. Paola <paola@dialipc-gw.ece.arizona.edu> wrote:
>My particular interest in this problem is the image compression aspect.
>It seems to me that lossless compression could be used to compress the
>most important images (ie, high-resolution satellite imagery) and achieve
>25 to 50% compression. The atmospheric images (ie, for creating Jupiter
>weather movies, etc) could be compressed using JPEG or even MPEG where
>compression rates of 10:1 or even 100:1 are possible.
I'm not sure about the imaging instruments, but the Plasma Working
Group will be using a routine similar to JPEG and also compressing
the data enough to loose some resolution. The instruments' data
from the two Earth flybys and theoretical models of the expected data from
Jupiter were used to determine an acceptable level of loss.
>My questions to anyone out there (JPL people??) are:
Well, a grad student working for one of the IDSs...
>2) What is the computing capability of the Galileo computer(s)?
That's hard to say: It has 19 separate computers. Six control the
spacecraft itself and the rest are built into on instrument or
another. Some of the instrument computers can cooperate with
the main computers, some can only do so in a limited manner.
Altogether, the spacecraft has 320k of RAM and 41k of ROM. The
six main computers are built around the 1802 microprocessor and
share a set of four memory units. Their total capacity is about
120k plus 32k in two other units dedicated to housekeeping. The
system's synchronization clock runs at 806.4 kHz, but for some
operations the system runs at about half that speed.
>4) What will the nominal bit rate be (ie, the LGA-DSN link) without
> compression?
The data rate will be between 8 and 14 bits per second, depending on
the relative positions of Earth and Jupiter.
>5) Are there going to be different algorithms or lossy compression
> quality levels for different types of imagery?
I don't know if different algorithms will be used; given the limited
on-board memory, I doubt it. Most instruments will not, however,
be using loss free compression. The level of compression, and the
amount of data lost, will be determined for each instrument
separately. The various Working Groups will decide on the best
level of loss, based on the available data rate and what they expect
to see (e.g. are they better off with two, noisy images of different
things or one clean image?)
> ...Maximum resolution ought
> to be obtained even if it means doing it over 4 or 5 years and using
> lossy compression (although it would be nice to avoid that as well).
Unfortunately, we don't have four or five years. All of the flyby
data has to be stored on tape and sent back before the next
flyby (otherwise, there would be no room to record the next flyby.)
That means we have only about a month to send back each tape full
of data.
Frank Crary
CU Boulder
Frank Crary (fcrary@ucsu.Colorado.EDU) wrote:
: Unfortunately, we don't have four or five years. All of the flyby
: data has to be stored on tape and sent back before the next
: flyby (otherwise, there would be no room to record the next flyby.)
: That means we have only about a month to send back each tape full
: of data.
Without the HGA, the ability to return most of the scientific data
relies on the operation of the single tape recorder onboard Galileo.
Earlier in the mission, before the first attempt to open the HGA, a
few images of Venus were returned at low rate using the DMS MRO technique.
At the time, there was reluctance to use that technique very much due
to wear and tear on the tape recorder.
But now things have changed, and we have no choice but to rely on the tape
recorder and DMS MRO to return ALL scientific data.
Are there any estimates as to how long the tape recorder will hold up
under the new mode of operation?
If the tape recorder fails, what scientific operations will still be
possible?
--
Steve Derry
<s.d.derry@larc.nasa.gov>
In article 2G3@cnsnews.Colorado.EDU, fcrary@ucsu.Colorado.EDU (Frank Crary) writes:
>>...The antenna situation is clearly going to constrain
>>such ideas considerably; notably, the Io dive isn't going to be possible
>>without real-time picture transmission.
>
>I'm not so sure about that: We aren't doing a second Io flyby because
>the spacecraft _might_ not survive the radiation. But there is also a
>good chance that it would. The odds aren't good enough to bet a
>working spacecraft on in the middle of its mission. But at the end
>of the mission, when we have very little to loose, an Io flyby
>might be worth it. The data could not be sent back in real time, but
>if the spacecraft survived, we would have plenty of time to
>send the data back. Essentially, it would be a gamble; but at the
>end of the mission it might not be a bad bet.
>
> Frank Crary
> CU Boulder
The fact that you mentioned a second Io flyby, does this mean it is being
considered? If so, what extra data would we gain and who would make the
final decision whether to do it or not and at what stage of the mission is
this decision most like to be made.
I suppose, to answer my question about what extra data would we gain, a
second flyby of Io would give us better resolution and detailed info that
the first flyby may miss due to the HGA being out of action. Is this correct?
Mark
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+
|Mark Slater | E-mail : etlmksr@etlxd30.ericsson.se |
|Ericsson Ltd, Burgess Hill, UK | Tel : (0444) 234403 (day) |
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+
In article <1993Nov25.083558.5280@ericsson.se> etlmksr@etlxd30.ericsson.se writes:
>... you mentioned a second Io flyby, does this mean it is being
>considered? If so, what extra data would we gain and who would make the
>final decision whether to do it or not and at what stage of the mission is
>this decision most like to be made.
I'm sure it's in the pot with all the other extended-mission ideas. They
probably won't make a firm decision until fairly late in the primary mission,
because they can't pick an extended mission without knowing how much fuel
will be left for it and what kind of shape the spacecraft (especially the
tape recorder) will be in. The results from the early part of the primary
mission are certainly going to influence the priorities, too -- notably, the
results from the first Io flyby are surely going to be a major factor in
the priority assigned to a second Io flyby. I'd expect that the highest
priority for an extended mission would be filling in any gaps in the data
from the primary mission (either data lost due to problems, or places where
a little more data would help make sense of the primary-mission data).
As for who makes the decision, I couldn't quote you the names of the
committees off the top of my head, but basically the science people will
make recommendations, based on their priorities and what the engineering
people tell them about feasibility, and JPL will make the final choice,
subject to approval from NASA and funding from Congress.
As for what would be gained: basically, a second look at Io. :-) Among
other considerations, remember that only one side of Io will be sunlit
during the first flyby, which means there will be little imaging of the
other side.
--
Belief is no substitute | Henry Spencer @ U of Toronto Zoology
for arithmetic. | henry@zoo.toronto.edu utzoo!henry
|
| 560.913 | End of Mission | VERGA::KLAES | Quo vadimus? | Thu Dec 09 1993 19:33 | 60 |
| Article: 78551
From: lad@charybdis.JPL.NASA.gov (Lou D'Amario)
Newsgroups: sci.space
Subject: Galileo: End of Mission
Date: 29 Nov 1993 18:37:34 GMT
Organization: Jet Propulsion Laboratory, NASA/Caltech
The 23-month duration for the Galileo Jupiter orbital mission
was determined by purely budgetary constraints. The final encounter in
the satellite tour occurs on November 6, 1997, 23 months after arrival
at Jupiter on December 7, 1997. It didn't work out that way by luck -
we designed the satellite tour that way. In actuality, the mission
will end when either one the following conditions is satisfied:
1. Congress fails to appropriate funds to continue the mission.
2. On board propellant used to control the spacecraft trajectory
and attitude is exhausted. (By the way, the correct term is
*propellant* not *fuel*; we could, have lots of fuel left
but if there isn't any oxidizer left, it won't be of any use.)
3. A spacecraft hardware or software failure precludes continued
operation of the spacecraft. (The intense Jupiter radiation
environment will eventually cause hardware failures.)
Current propellant margin calculations predict that there will
be 5 kg of usable propellant remaining at the end of the baseline
23-month mission at the 90% probability level. The 90% probability
level is what is used for mission planning purposes. (At 50%
probability, the propellant margin is 17 kg.) The propellant margin
calculation allows 13 kg of propellant for Project Manager Reserves
and 13 kg of propellant for *science turns*. Science turns are
spacecraft turns for observing particular targets that are
unobservable given the nominal near-Earth-pointed attitude of the
spacecraft. One satellite encounter requires about 5-10 kg of propellant.
Of course, Galileo will continue to orbit Jupiter even after
the *mission* ends and the spacecraft trajectory is no longer being
controlled. Sometime between several hundred to several thousand years
after the end of the mission, Galileo will probably impact either one
of the Galilean satellites (Io, Europa, Ganymede, or Callisto) or
Jupiter itself due to trajectory perturbations from chance encounters
with the Galilean satellites. It is much less likely that Galileo will
be ejected from the Jupiter system.
The most recent paper on the status of the Galileo mission is
IAF Paper 93.Q.5.411, *Performing the Galileo Jupiter Mission with the
Low-Gain Antenna and an Enroute Progress Report*, by W. O'Neil et al,
presented at the 44th IAF Congress, October 16-22, 1993 in Graz, Austria.
Hope this information clears up any misconceptions on what
*end of mission* means for Galileo.
Louis A. D'Amario
Galileo Deputy Navigation Team Chief
Jet Propulsion Laboratory
"NASA turns dreams into realities and makes science fiction
into fact." -- Daniel S. Goldin, NASA Administrator
|
| 560.914 | Why no camera on the drop probe | VERGA::KLAES | Quo vadimus? | Thu Dec 23 1993 17:19 | 72 |
| Article: 80333
Newsgroups: sci.space
From: malin@esther.la.asu.edu (Mike Malin)
Subject: Re: Why no Camera on the Galileo Probe
Sender: news@ennews.eas.asu.edu (USENET News System)
Organization: Mars Observer TES Project, ASU, Tempe AZ
Date: Wed, 22 Dec 1993 02:49:36 GMT
Just to amplify on Henry Spencer's response: I was the PI on
the proposal for a camera on the Galileo Probe. As Henry noted, the
available technology would have limited us to a few 256 X 256 pixel
images in three color bands. This is primarily because the original
bandwidth was 44 bits per second for about 30 minutes, to be shared
with all instruments. We asked for 1/4, which works out to ~20 Kb.
We used an 1802 microprocessor and eight 48 kbit RAM to do 12:1 lossy
multispectral compression (never done at the time) and were able to get
two 256 X 256 images in three colors. We noted that for each
additional 30 minutes and 11 bps, we could take another image.
Compare this to Huygens ca. 8000 bps for ca. 3 hrs, 70% of which goes
to DISR (60.5 Mbits), and you can see the difference (of order 3000).
I beg to differ with Robert Dempsey, who argues in his response:
Ever fly through a cloud in a plane? Not much to image. its better
to put good camera's on the orbiter rather than waste weight on the
atm probe for cameras that would deliver a couple of pictures than
be useles (and thdestroyed).
Images of cloud structures would be very useful. Not all images of
clouds are necessarily taken from WITHIN clouds. By judicious use of
on-board processing, you can eliminate sending images without scene
content and send back images with something in them. Also, depending
on the camera, even relatively featureless images of, for example, the
anti-solar direction, could tell things (e.g., about aerosol size,
state, etc.) that other instruments might not address.
The particular sequence we proposed for Galileo had the camera take
four partial frames during approach and just prior to atmospheric entry,
clearly above the clouds and looking obliquely at the entry location,
and then one or more images after entry while descending on the parachute,
this time looking out mostly to the side.
There are several reasons why we weren't selected: this was my first
mission instrument proposal as PI (I was 26) and I didn't put enough
effort in recruiting a science team to work up the justification, the
review panel balked at the cost (roughly a million dollars per picture
in 1977 dollars) and the relative use of data rate (it has since gone
up so much it wouldn't have been a problem), and the design was, like
everything else I have done, significantly ahead of its time (i.e., so
no one believed we could do it). I believe we were ranked 40 out of
41 proposals. However, I sill maintain they would have been pretty
spectacular pictures (and I think we would have probably gotten a
dozen or so).
Mike Malin
Ex-Mars Observer Camera Principal Investigator
Unsuccessful proposer of Jupiter Orbiter/Probe 1981 Mission (later to
become Galileo) Probe Imaging Experiment (PIE) (1976)
Unsuccessful proposer of Cassini Orbiter/Huygens Titan Probe 1997
Mission Descent Imaging Spectrometer/High Resolution Camera
(DISC) (1990)
...Its not because I don't try...
Art thou pale for weariness
Of climbing heaven, and gazing on the earth,
Wandering compassionless
Among the stars that have a different birth,-
And ever changing, like a joyless eye
That finds no object worth its constancy? -- Shelley
|
| 560.915 | February 17 | VERGA::KLAES | Quo vadimus? | Fri Feb 18 1994 18:34 | 42 |
| Article: 5373
Newsgroups: sci.space.news
From: Admin@ccmail.jpl.nasa.gov (JPL Public Information)
Subject: Galileo status 2/17/94
Sender: digester@news.arc.nasa.gov
Organization: Jet Propulsion Laboratory
Date: Thu, 17 Feb 1994 19:47:01 GMT
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
February 17, 1994
This week the Galileo spacecraft completed a very small
trajectory correction maneuver (velocity change 0.1 meter per second,
or about one quarter of a mile per hour), to adjust its flight path
for the probe entry into Jupiter's atmosphere on December 7, 1995,
almost two years from now. The principal maneuver to target for
Jupiter completed last October took five days and changed the
spacecraft velocity by about 38 meters per second. Opportunities for
additional corrections are scheduled for next year. In July 1995 the
probe will be released to continue in this flight path; shortly after
that the orbiter spacecraft will be re-targeted to go into Jupiter orbit.
Tuesday night the spacecraft began surveying its tape- recorded
data on the asteroid Ida to search for Ida images to be played back in
the next few months. The Ida science playback will be transmitted at
40 bits per second beginning in March when Earth and Galileo come close
enough (for the last time) to support that rate over the low-gain antenna.
The spacecraft is operating normally in the all-spin mode,
rotating at about 2.9 rpm. Its health and performance are excellent.
Galileo is about 592 million kilometers (368 million miles) from the
Sun, and almost the same distance from Earth. It has traveled about
3.3 billion kilometers (2 billion miles) in its complex, looping
trajectory since it was launched in October 1989. The spacecraft's
speed relative to the sun is almost 13 kilometers per second (29,000 mph).
|
| 560.916 | Possible moon orbiting planetoid Ida | VERGA::KLAES | Quo vadimus? | Thu Mar 03 1994 20:34 | 49 |
| From: US3RMC::"ASTRO%GITVM1.BITNET@uga.cc.uga.edu" "Astronomy Discussion
List" 3-MAR-1994 16:39:21.67
To: Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
CC:
Subj: Possible Moon Observed by Galileo Around Asteroid
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Contact: Franklin O'Donnell
FOR IMMEDIATE RELEASE March 3, 1994
NASA's Galileo spacecraft observed what is probably a
natural satellite of the asteroid Ida -- which would be the first
moon of an asteroid ever sighted -- during its flyby last August
28, scientists have reported.
The object is revealed in data samples now being transmitted
by the spacecraft and analyzed by scientists at the Jet
Propulsion Laboratory.
Sampled data from both Galileo's solid-state imaging system
and its near-infrared mapping spectrometer give indications of
the object.
Because Galileo has been transmitting data back to Earth at
a low rate of 40 bits per second, a complete image of the
suspected moon will first become available in about three weeks.
Galileo has completed nearly 90 percent of its 3.8-billion-
kilometer (2.4-billion-mile) journey to Jupiter. It will go into
orbit around the giant planet after exploring the atmosphere with
an instrumented probe on December 7, 1995. JPL manages the
Galileo project for NASA's Office of Space Science.
#####
% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% Date: Thu, 3 Mar 1994 19:39:03 +0000
% Sender: Astronomy Discussion List <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
% From: Ron Baalke <BAALKE@KELVIN.JPL.NASA.GOV>
% Subject: Possible Moon Observed by Galileo Around Asteroid
% X-To: astro@gitvm1.bitnet
% To: Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
|
| 560.917 | Trying to transmit data at 160 bps | JVERNE::KLAES | Be Here Now | Mon Mar 07 1994 20:34 | 45 |
| Article: 3217
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: alt.sci.planetary
Subject: Re: Possible Moon Observed by Galileo Around Asteroid
Date: 5 Mar 1994 03:57 UT
Organization: Jet Propulsion Laboratory
In article <CM63KI.M8p@cix.compulink.co.uk>,
johnorourke@cix.compulink.co.uk ("John O'Rourke") writes...
>You mentioned that Galileo is only sending data back at 40 bps. Is this
>a technical limitation or is it due to the distances involved or is it
>because it doesn't need to be any quicker because it's not passing very
>much of interest for most of its journey so a low transfer rate will do?
The High Gain Antenna on Galileo didn't open up all the way, so the
spacecraft is sending back all of the data through its Low Gain
Antenna. The next three months will be the last window of opportunity
for Galileo to transmit at 40 bps with the current DSN capabilities.
The second portion of the Ida data will be played back during that
time, including the new moon images. In July, Galileo will record the
Jupiter/comet observations to its tape recorder. At that time it will
be then limited to a 10 bps telemetry rate using the DSN's 70 meter
antenna. I don't know what the plan is to send back the comet/Jupiter
data.
I'm working on the Galileo S-Band project that is making the
improvements to the DSN so that Galileo can transmit the data back up
to 160 bps. However, our system isn't due to go online until early
1996, to playback the probe and Io data after Galileo has arrived at
Jupiter. We're making excellent progress and have already recorded
data with our prototype system from Galileo. Two days ago we've
cross-correlated Galileo's signal from two different antennas at
Goldstone. However, we do still have a long way to go. There has
been some inquiries from above about using our system for the
Jupiter/comet playback but it is hard to tell right now. We'll just
have to wait and see.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ Galileo S-Band | A mind stretched by a new
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | idea can never go back to
|_____|/ |_|/ |_____|/ | its original dimensions.
|
| 560.918 | Ida moon image to be released March 23 | JVERNE::KLAES | Be Here Now | Tue Mar 22 1994 21:02 | 53 |
| From: VERGA::US1RMC::"ASTRO%GITVM1.BITNET@uga.cc.uga.edu" "Astronomy
Discussion List 22-Mar-1994 1722" 22-MAR-1994 17:18:27.31
To: Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
CC:
Subj: Ida Moon Press Conference
Sarah Keegan
Headquarters, Washington, D.C.
March 22, 1994
(Phone: 202/358-1547)
Franklin O'Donnell
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
EDITORS NOTE: N94-25
ASTEROID MOON PHOTO TO BE RELEASED AT PRESS CONFERENCE
The first ever photograph of a moon of an asteroid, taken by
NASA's Galileo spacecraft, will be released at a press conference
Wednesday, March 23.
The press conference, beginning at 1 p.m. EST, will originate
from NASA's Jet Propulsion Laboratory, Pasadena, Calif., and will be
carried live on NASA Select television with two-way question and
answer capability.
Discussing the major discovery will be William O'Neil, Galileo
project manager; Dr. Torrence Johnson, Galileo project scientist; Dr.
Michael Belton, team leader for Galileo's imaging system; Dr. Robert
Carlson, principal investigator for Galileo's near-infrared mapping
spectrometer; and Dr. Clark Chapman, a member of the Galileo imaging team.
Galileo took pictures of and collected other data on the small
moon of the asteroid Ida during its flyby last Aug. 28. The images
were not received on Earth until recently because the spacecraft is
transmitting over its low-gain antenna at a very slow rate.
NASA Select is available on Spacenet 2, transponder 5, channel
9, 69 degrees West, transponder frequency is 3880 MHz, audio
subcarrier is 6.8 MHz, polarization is horizontal.
-end-
% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% Date: Tue, 22 Mar 1994 21:39:22 +0000
% Sender: Astronomy Discussion List <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
% From: Ron Baalke <BAALKE@KELVIN.JPL.NASA.GOV>
% Subject: Ida Moon Press Conference
% X-To: astro@gitvm1.bitnet
% To: Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
|
| 560.919 | Ida's moon revealed | JVERNE::KLAES | Be Here Now | Wed Mar 23 1994 19:48 | 175 |
| From: VERGA::US1RMC::"ASTRO%GITVM1.BITNET@uga.cc.uga.edu" "Astronomy
Discussion List 23-Mar-1994 1645" 23-MAR-1994 16:40:04.30
To: Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
CC:
Subj: Ida's Moon
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Contact: Franklin O'Donnell
FOR IMMEDIATE RELEASE March 23, 1994
The first-ever photograph of a moon of an asteroid, sent to Earth
by NASA's Galileo spacecraft, was released by the space agency today.
The photo, of asteroid 243 Ida and its newly discovered natural
satellite, was taken by Galileo as the spacecraft flew past Ida last
August 28. It was not transmitted to Earth until recently because the
spacecraft is sending back data at a very slow rate.
According to team scientists at NASA's Jet Propulsion Laboratory,
the image together with data from Galileo's near- infrared mapping
spectrometer are the first conclusive evidence that natural satellites
of asteroids exist.
The discovery gives scientists an intriguing new clue in deciphering
the origins and evolution of these ancient, rocky bodies, most of which
orbit the sun in the main asteroid belt between Mars and Jupiter.
Even so, many pieces of information on the newly found moon --
where it came from, how it came to be orbiting Ida and the details of
that orbit -- are still unclear.
"It was previously thought that natural satellites of asteroids
could form, but they probably weren't common," said Dr. Torrence
Johnson, Galileo project scientist. "Having found one fairly quickly,
we can say that they're probably more common than previously thought."
From the photo and spectrometer data, team scientists estimate
that the natural satellite is about 1.5 kilometer (1 mile) across in
this view, and appears to be at a distance of about 100 kilometers (60
miles), plus or minus 50 kilometers (30 miles), from Ida's center.
The position will be more accurately determined as new data are
analyzed. Ida itself is about 56 by 24 by 21 kilometers (35 by 15 by
13 miles) in size.
As yet they do not know the parameters of the object's orbit --
critical information that can reveal Ida's mass. Combined with
measurements of Ida's size and volume, that can tell scientists the
asteroid's density, offering more clues as to what it is made of.
The data from Galileo's near-infrared mapping spectrometer --
which scans space objects at a variety of wavelengths to reveal their
chemical composition -- suggest that Ida's moon is made more or less
from the same kind of material as Ida. As an S-type asteroid, Ida is
composed mostly of silicate rocks.
Scientists are certain, in any event, that the moon's surface is
not composed mostly of carbonaceous material, as are the many asteroids
that are termed C-type asteroids.
Further information on the object's composition will become
available as color pictures and more detailed data from the
spectrometer are transmitted to Earth over the next few months.
Galileo scientists believe the moon may have been created at the
same time as Ida -- when an older, larger asteroid was shattered in a
collision with another asteroid, giving birth to dozens of smaller
asteroids.
Ida is a member of the Koronis family of asteroids, which
scientists believe was created when a larger body perhaps 200 to 300
kilometers (120 to 180 miles) in diameter was smashed relatively
recently -- at least considerably after the solar system formed some
4.5 billion years ago. (The family was named for Koronis, one of the
asteroids that belongs to it.)
Alternatively, it is possible that Ida was hit by a smaller
object even more recently, leaving a crater on the asteroid and
throwing off the material that became the small moon.
"Ida's age is baffling, because the craters visible on its
surface suggest that it is old, but being a part of the Koronis family
suggests it is younger," said Johnson.
"In any event, we don't believe that Ida and its moon could go
back to the formation of the solar system," he added. "It's generally
thought that a small object like that moon could not survive this
long; sooner or later it would itself be broken up in a high-speed
collision with an even smaller object."
Galileo scientists also believe it is virtually impossible
that the moon is a "captured object," something created completely
separately from Ida that happened to wander near the asteroid and be
caught by its gravitational field. According to the laws of celestial
mechanics, such an event would deflect the smaller object, but it
would not be captured into orbit unless a third force of some kind
slowed it down.
"Once we have determined the object's orbit, we can estimate time
scales and make better guesses as to where it came from," said Johnson.
Launched in October 1989, Galileo made its closest approach to
Ida at a distance of 2,400 kilometers (1,500 miles) last August while
flying through the asteroid belt en route to its final destination --
the giant planet Jupiter, where it will go into orbit in December 1995.
Because Galileo is sending data back to Earth through its
low-gain radio antenna, it must transmit at slow rates. One portrait
of Ida -- a mosaic of five separate frames -- was received shortly after
the flyby, but later pictures had to wait because telecommunications
conditions became unfavorable as Galileo's distance from Earth increased.
In the meantime they were stored on Galileo's onboard tape recorder,
awaiting playback this spring.
Scientists say that the newly found moon was outside the
boundaries of the picture of Ida released last September.
Ground controllers instructed Galileo to send back more portions
of photos and other data beginning in February as the spacecraft's
distance from Earth decreased and radio communications with the
spacecraft improved.
In preparation for complete playback, they commanded the
spacecraft to transmit strips of each image -- called "jail bars" by
the project's engineers and scientists -- so that they could locate
Ida accurately in images stored on Galileo's recorder. Later, portions
of an image containing Ida could be selected for playback in their
entirety.
On February 17 -- a day after the first of these "jail bars" was
sent back from Galileo -- evidence of the natural satellite was noticed
in one set of image strips by Ann Harch, a Galileo imaging team associate
at JPL. It took several days to verify that what appeared to be a moon
was not, in fact, an artificial effect of some kind.
On February 23, scientists examining similar preliminary data
from a chemical map obtained by the near-infrared mapping spectrometer
discovered an unusual object in their data. By February 28, scientists
from both the camera and spectrometer teams concluded that they had a
confirmation.
Amateur astronomers for many years have observed the light of
stars blinking off and on as objects such as asteroids pass in front
of them in events called stellar occultations. Some have reported
"blinkouts" that suggest that some asteroids have moons, but such
reports have never been confirmed by definite second sightings.
Galileo's discovery is thus the first unambiguous evidence of an
asteroid moon.
Other images that may show the asteroid moon are still stored on
Galileo's tape recorder, and will be played back later this spring.
Among them is an image that is expected to be at least three times
sharper than the first image received.
The newly found moon has been provisionally designated "1993
(243) 1" -- meaning that it is the first natural satellite discovered
in 1993 at Ida, which was the 243rd asteroid discovered over the past
two centuries. The moon will be formally named later by the
International Astronomical Union.
JPL manages the Galileo Project for NASA's Office of Space Science.
% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% Date: Wed, 23 Mar 1994 21:20:14 +0000
% Sender: Astronomy Discussion List <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
% From: Ron Baalke <BAALKE@KELVIN.JPL.NASA.GOV>
% Subject: Ida's Moon
% X-To: astro@gitvm1.bitnet
% To: Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
|
| 560.920 | Ida Moon images available | JVERNE::KLAES | Be Here Now | Wed Mar 23 1994 20:26 | 41 |
| Article: 54866
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.astro,alt.sci.planetary
Subject: Ida Moon Images Available
Date: 23 Mar 1994 21:05 UT
Organization: Jet Propulsion Laboratory
GIF files of images of the newly discovered moon of the asteroid Ida
taken by NASA's Galileo spacecraft are available at the JPL Info
public access computer site.
The files are:
IDAMOON.GIF 45K Ida and moon P-43731
IDAMOON2.GIF 24K Closeup of asteroid moon P-43732
The files are in the directory `news'; after about a month they
are moved to the directory `images'.
The JPL Info site may be accessed via Internet using anonymous ftp
to jplinfo.jpl.nasa.gov (137.78.104.2); or by dialup modem to
+1 (818) 354-1333, parameters N-8-1, up to 14.4 kbps speed.
Hardcopy prints of the images may be ordered using the "P-#"
reference numbers shown above from the following contractor firm:
Newell Color Lab
221 N. Westmoreland Avenue
Los Angeles, CA 90064
USA
telephone +1 (213) 380-2980
fax +1 (213) 739-6984
[end]
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ Galileo S-Band | A mind stretched by a new
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | idea can never go back to
|_____|/ |_|/ |_____|/ | its original dimensions.
|
| 560.921 | From the regular media | SPARKL::KLAES | Be Here Now | Thu Mar 24 1994 14:27 | 69 |
| Article: 3878
From: clarinews@clarinet.com (Reuters)
Newsgroups: clari.local.los_angeles,clari.tw.space
Subject: Nasa Scientists Discover Asteroid has a Moon
Date: Wed, 23 Mar 94 15:50:09 PST
PASADENA, Calif. (Reuter) - NASA's Galileo spacecraft has
sent back photographs showing for the first time an asteroid
orbited by its own moon, scientists said Wednesday.
``There have been hints of satellites in the past that have
been detected by ground-based observers. But this is the first
confirmed and clear detection of a satellite of an asteroid,''
Clark Chapman, a member of the Galileo imaging team, said.
Project scientist Torrence Johnson hailed the discovery of
the moon as a tremendous accomplishment.
``I'm sorry if that sounds like an Academy Award acceptance
speech, but when you find something like this it sort of feels
like that,'' Johnson told a news conference.
NASA's Jet Propulsion Laboratory in Pasadena released black
and white photographs showing the asteroid Ida accompanied by a tiny
moon, which project scientists have provisionally baptized Ida 2.
Scientists said the discovery gives them a new clue in
deciphering the origins and evolution of asteroids, most of
which are found in the asteroid belt between Mars and Jupiter.
Galileo, launched in October 1989, is on a 2.4 billion mile
voyage to Jupiter, the biggest planet in the solar system, where
it is expected to go into orbit in December 1995. The project
has cost more than $1 billion.
The space probe photographed Ida when it passed by at a
distance of about 1,500 miles last August.
But the images were not received on Earth until recently
because the spacecraft has been transmitting at a very slow rate
the last few months due to its great distance from Earth.
The discovery was made February 17 when a laboratory
assistant noticed a very bright object on one photograph.
Data from another experiment on Galileo -- a near-infrared
mapping spectrometer -- confirmed the object was in fact a moon
of the asteroid.
The asteroid is about 35 miles long and about 12 miles wide,
while the moon, which is about 60 miles from Ida, is about one mile across.
The scientists hope to get higher resolution images of Ida
and its moon as more data are sent back to Earth.
Michael Belton, team leader from Galileo's imaging system,
said the team would search for more satellites of asteroids.
``If you find one, this is probably not the only one that is
there. We'll have to see,'' he said.
Chapman said the discovery may permit scientists to find out
Ida's density and lead to insights into planetary geology.
There are several theories regarding the satellite's origin. The
preferred one is that Ida and its moon may be fragments of a larger
asteroid that broke up hundreds of millions of years ago and that one
fragment went into orbit around Ida, he said.
|
| 560.922 | IDA gifs available for a limited time. | SKYLAB::FISHER | Carp Diem : Fish the Day | Thu Mar 24 1994 15:32 | 7 |
| You can get idamoon.gif and idamoon2.gif from BULOVA::SYS$TRANSFER for a limited
time. idamoon is GORGEOUS! It is a shot of ida with the Ida II off to one
side. Idamoon2 is a of the moon itself. Looks like it might be a blow-up of
the moon section of idamoon; it is quite blurry. You can make out its shape
much better, however.
Burns
|
| 560.923 | | PRAGMA::GRIFFIN | Dave Griffin | Thu Mar 24 1994 16:24 | 12 |
| Via the Web: I have a pointer in the Space Archives home page
(http://www-space.lkg.dec.com/space-archives.html), it's under New Information
for now. Eventually they'll migrate to the Galileo images page.
Via good ol' DECnet: pragma::public:[nasa]gal_idamoon1.gif , ...2.gif
- dave
p.s. Thanks for retrieving Burns.. I didn't have time yesterday.
|
| 560.924 | | SKYLAB::FISHER | Carp Diem : Fish the Day | Thu Mar 24 1994 17:04 | 5 |
| Ok, I'll delete mine.
Thanks Dave.
Burns
|
| 560.925 | How they know Ida's moon is Ida's moon | JVERNE::KLAES | Be Here Now | Wed Mar 30 1994 15:57 | 29 |
| From: VERGA::US4RMC::"ASTRO%GITVM1.BITNET@uga.cc.uga.edu" "Astronomy
Discussion List 30-Mar-1994 0132" 30-MAR-1994 01:28:04.76
To: Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
CC:
Subj: Re: Photos of Ida's Moon Released
>One question has bugged me on this - how do they know the "moon" is in
>fact orbiting Ida? I know the chances are slim, but could it be just
>an "Ida-crossing" asteroid?
Excellent question. The moon's position was initially derived by
comparing the image data against the NIMS data. Since the two data
sets were taken about 6 minutes apart, the moon's position could be
triangulated and was determined to be about 100 km from Ida and
slightly in the foreground. It was also determined that the moon was
moving slowly relative to Ida, and based on this the odds were very
heavily in favor that the object was in orbit. Based on this data
there is something like 1 out of 10 million chance that the object
could just happen to be flying by Ida without being in orbit.
% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% Date: Wed, 30 Mar 1994 06:22:55 +0000
% Reply-To: Astronomy Discussion List <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
% Sender: Astronomy Discussion List <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
% From: Ron Baalke <BAALKE@KELVIN.JPL.NASA.GOV>
% Subject: Re: Photos of Ida's Moon Released
% X-To: astro@gitvm1.bitnet
% To: Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
|
| 560.926 | More images of Ida's moon | MTWAIN::KLAES | Keep Looking Up | Wed May 25 1994 18:12 | 108 |
| From: US4RMC::"baalke@kelvin.jpl.nasa.gov" "Ron Baalke" 25-MAY-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: New Galileo Asteroid Moon Images Released
Michael Braukus
Headquarters, Washington, D.C. May 25, 1994
(Phone: 202/358-1547)
James H. Wilson
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
RELEASE: 94-83
NEW GALILEO ASTEROID MOON IMAGES, DATA RELEASED
New pictures of the asteroid 243 Ida and its newly discovered
moon taken by NASA's Galileo spacecraft were released today by mission
scientists.
New data from Galileo suggest that although Ida and its
natural satellite -- the first asteroid moon ever photographed --
are similar in color and brightness, they appear to be composed of
different types of material, the scientists said.
The scientists also reported that new results show that Ida
is more irregular in shape than Gaspra, another asteroid which the
Galileo spacecraft encountered two years earlier.
Galileo took multiple images of Ida seen from different
angles as the asteroid rotated during the spacecraft encounter.
Scientists also used the images to begin estimating an orbit
for the asteroid's tiny moon. Its motion, in the same direction as
Ida's rotation, appears to be in a plane viewed nearly edge-on by the
spacecraft -- making it difficult to determine the exact orbital shape
and period.
"A circular orbit at 60 miles (90 kilometers), nearly in Ida's
equatorial plane, with a period of about one Earth day, appears to fit
the observations we have now," said Kenneth P. Klaasen, a member of
the imaging team.
"However, a range of elliptical orbits cannot be ruled out
yet," he added. "Other observations that are still on Galileo's
onboard tape recorder -- to be played back next month -- should permit
us to improve the calculation."
There are different explanations for the origin of Ida's one
mile-diameter (1.5-kilometer) moon. It might be a large block thrown
off during an impact that formed one of the large craters visible on
Ida's surface.
"More likely," said imaging team member Dr. Clark Chapman,
"the moon was formed during the cataclysmic fragmentation and
disruption of a larger asteroid in which Ida itself was formed.
"In this scenario, the little moon was ejected from the
explosion in practically the same orbit as Ida, and was captured in
the larger object's gravitational field," Chapman continued, "while
most other fragments went into independent orbits around the Sun."
Galileo's near-infrared mapping spectrometer, which initially
confirmed the discovery of Ida's moon, provided the data for thermal
and mineralogical maps of the surface of Ida and mineralogical studies
of its moon.
"We have good data on what minerals make up these bodies, "
said Dr. Robert Carlson, principal investigator for the spectrometer.
"The areas on Ida's surface where we have our best data appear to be
predominantly olivine, with a bit of orthopyroxene -- while its moon
is quite different, with a roughly equal mixture of olivine,
orthopyroxene, and clinopyroxene."
"This suggests the moon is not a chip off the asteroid."
These and other results from the Ida encounter will be
discussed by the Galileo scientists in a special session of the
American Geophysical Union's spring 1994 meeting in Baltimore, Md.,
on Thursday, May 26.
Ida orbits the Sun at an average distance of 270 million miles
(440 million kilometers) in about the middle of the asteroid belt
between Mars and Jupiter. The asteroid is about 36 miles (58
kilometers) long and 14 miles (23 kilometers) wide, and rotates once
every 4 hours, 40 minutes. One of only two asteroids ever observed
close-up, it was encountered Aug. 28, 1993, by the Galileo spacecraft
on its way to Jupiter.
Pictures and other scientific data taken during the flyby were
stored on Galileo's onboard tape recorder; playback is still underway.
Ida's moon was discovered in data played back and analyzed in
February and March 1994.
Galileo executed its other asteroid flyby, of the rocky body
Gaspra, on Oct. 29, 1991.
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages
the Galileo project for NASA's Office of Space Science, Washington, D.C.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | JPL/Telos |
___| | | | |__) |/ | | |__ Galileo S-Band | I stare into space for a
/___| | | | ___/ | |/__ /| Pasadena, CA | living.
|_____|/ |_|/ |_____|/ |
|
| 560.927 | New Ida images available at JPL | MTWAIN::KLAES | Keep Looking Up | Wed Jun 01 1994 17:25 | 29 |
| From: US4RMC::"baalke@kelvin.jpl.nasa.gov" "Ron Baalke" 1-JUN-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: New Ida Images Available at JPL
GIF versions of Ida images released last week are now are available at
the Jet Propulsion Laboratory's public access computer site.
The site may be accessed over Internet by anonymous ftp to
jplinfo.jpl.nasa.gov (137.78.104.2), or by dialup modem to
+1 (818) 354-1333.
The files, in the directory `news', are as follows:
idahires.gif - High resolution of a portion of Ida.
idamnclr.gif - False color image of Ida and its moon.
idarotat.gif - Six low resolution images of Ida from different angles
Caption files describing the images in more detail are embedded in the
images (GIF89a format).
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | JPL/Telos |
___| | | | |__) |/ | | |__ Galileo S-Band | I stare into space for a
/___| | | | ___/ | |/__ /| Pasadena, CA | living.
|_____|/ |_|/ |_____|/ |
|
| 560.928 | Update - June 2 | MTWAIN::KLAES | Keep Looking Up | Tue Jun 07 1994 03:15 | 43 |
| From: US4RMC::"yee@atlas.arc.nasa.gov" "Peter Yee" 3-JUN-1994 21:02:17.19
To: usenet-space-news@arc.nasa.gov
CC:
Subj: Galileo Status for 06/02/94 (Forwarded)
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
June 2, 1994
The Galileo spacecraft is now well beyond the asteroid belt,
heading for its mid-July observations of Comet Shoemaker-Levy-9's
impact with the night side of Jupiter. The spacecraft is still
transmitting scientific observations and images stored onboard
from its August 28, 1993, flyby of the asteroid Ida and its newly
discovered moon. The science team reported preliminary analyses
of Ida and the moon late last month.
The flight team is planning to have Galileo observe Comet
Shoemaker-Levy-9's multiple impacts from a distance of 240
million kilometers (150 million miles). The spacecraft will be
the only observer in a position to image the impact sites, which
will be out of view of Earth. The data will be stored on
Galileo's onboard tape recorder for later playback.
Almost a year later, in July 1995, the spacecraft will
release its Jupiter atmospheric entry probe. From that point,
the orbiter and probe will fly separately to Jupiter. Probe
entry, atmospheric data relay and orbit insertion will all occur
on December 7, 1995. The orbiter will then collect data about
Jupiter, its major moons and its magnetosphere for the next two years.
The Galileo spacecraft is operating normally, spinning at 3
rpm and transmitting over the low-gain antenna at 40 bits per
second. It is currently 678 million kilometers (421 million
miles) from the sun, about 570 million kilometers (350 million
miles) from Earth, and now less than 250 million kilometers (155
million miles) from Jupiter.
|
| 560.929 | Probe will observe 16 of the 21 impacts | MTWAIN::KLAES | Keep Looking Up | Tue Jun 07 1994 19:05 | 57 |
| From: US4RMC::"baalke@kelvin.jpl.nasa.gov" "Ron Baalke" 5-JUN-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: Galileo Set to Observe Comet Shoemaker/Levy Impacts
From the "JPL Universe"
June 3, 1994
Galileo set to observe 16 of 21 `pearls' in Shoemaker-Levy-9 string
JPL's Galileo spacecraft is scheduled to observe 16 of the
21 possible impacts of the fragments of Comet Shoemaker-Levy-9
with Jupiter this July, according to project scientist Dr.
Torrence Johnson.
Speaking at the 1994 spring meeting of the American
Geophysical Union in Baltimore last month, Johnson described
plans for the only observation platform actually able to
photograph the impact sites.
"Galileo's imaging system and its near-infrared mapping
spectrometer will divide up most of the opportunities," Johnson
said, "while the photopolarimeter observes several other events."
Galileo's ultraviolet spectrometer, plasma-wave sensors and
dust detector will also be involved in the effort, as will other
distant spacecraft and many observers on Earth. Galileo's camera
will be used in several different ways, including time-lapse
sequences with and without color filters, slow scans and very
long, sweeping scans with an open shutter.
"We're hoping that one or more of our observational schemes
will succeed in recording observations of the impact events
themselves with their immediate consequences, possibly including
large hot fireballs produced by the explosion of comet fragments
as they are stopped by Jupiter's atmosphere," Johnson said.
"Theories of what happens in such large atmospheric
impacts," he continued, "are important to an understanding of the
evolution of the early Earth and other planets, as well as the
later Cretaceous-Tertiary extinctions (of dinosaurs and many
other species). We hope for the first time to provide actual
observations that can test and improve these theories."
Galileo will be about 240 million kilometers (150 million
miles) from Jupiter, at an angle from which part of the night
side, including the comet impact site, is visible. All the
fragments will impact on the far side of Jupiter relative to the
Earth and sun.
The spacecraft will tape-record its images and other science
data, Johnson said, and play them back slowly over the next
several months. Playback of selected Shoemaker-Levy data from
Galileo may continue until the end of January 1995, using a
sample-and-select approach like that employed with the pictures
of asteroids Gaspra and Ida.
###
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | JPL/Telos |
___| | | | |__) |/ | | |__ Galileo S-Band | If you follow the herd, you
/___| | | | ___/ | |/__ /| Pasadena, CA | will eventually end up in the
|_____|/ |_|/ |_____|/ | slaughter house.
|
| 560.930 | Ida's moon may not be an "offspring" | MTWAIN::KLAES | Keep Looking Up | Tue Jun 07 1994 19:07 | 76 |
| From: US4RMC::"baalke@kelvin.jpl.nasa.gov" "Ron Baalke" 5-JUN-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: New Data on Ida's Moon
From the "JPL Universe"
June 3, 1994
New data from Galileo show Ida's moon not a chip off the old asteroid
New data from JPL's Galileo spacecraft suggest that although
asteroid 243 Ida and its newly discovered moon--the first
asteroid moon ever photographed--are similar in color and
brightness, they appear to be composed of different types of
material, mission scientists said.
The scientists also reported that new results show that Ida
is even more irregular in shape than Gaspra, another asteroid
which the Galileo spacecraft encountered two years earlier.
Galileo took multiple images of Ida seen from different
angles as the asteroid rotated during the spacecraft encounter.
Scientists also used the images to begin estimating an orbit
for the asteroid's tiny moon. Its motion, in the same direction
as Ida's rotation, appears to be in a plane viewed nearly edge on
by the spacecraft--making it difficult to determine the exact
orbital shape and period.
"A circular orbit at 90 kilometers (about 60 miles) nearly
in Ida's equatorial plane, with a period of about one Earth day,
appears to fit the observations we have now," said imaging team
member Kenneth Klaasen of the Imaging Systems Section 381.
"However, a range of elliptical orbits cannot be ruled out
yet," he added. "Other observations that are still on Galileo's
onboard tape recorder--to be played back later this month--should
permit us to improve the calculation."
Ida's 1.5-kilometer-diameter (1-mile) moon might be a large
block thrown off during an impact that formed one of the large
craters visible on Ida's surface.
"More likely," said imaging team member Dr. Clark Chapman,
"the moon was formed during the cataclysmic fragmentation and
disruption of a larger asteroid in which Ida itself was formed.
"In this scenario, the little moon was ejected from the
explosion in practically the same orbit as Ida, and was captured
in the larger object's gravitational field," Chapman continued,
"while most other fragments went into independent orbits around
the sun."
Galileo's near-infrared mapping spectrometer (NIMS), which
initially confirmed the discovery of Ida's moon, provided the
data for thermal and mineralogical maps of the surface of Ida and
mineralogical studies of its moon.
"We have good data on what minerals make up these bodies,"
said Dr. Robert Carlson, NIMS team leader. "The areas on Ida's
surface where we have our best data appear to be predominantly
olivine, with a bit of orthopyroxene--while its moon is quite
different, with a roughly equal mixture of olivine, orthopyroxene
and clinopyroxene.
"This suggests the moon is not a chip off the asteroid."
Ida orbits the sun at an average distance of 440 million
kilometers (270 million miles) in about the middle of the
asteroid belt between Mars and Jupiter. The asteroid is about 58
kilometers (36 miles) long and 23 kilometers (14 miles) wide, and
rotates once every four hours, 40 minutes. One of only two
asteroids ever observed close up, it was encountered Aug. 28,
1993, by Galileo on its way to Jupiter.
Pictures and other scientific data taken during the flyby
were stored on Galileo's onboard tape recorder; playback is still
under way. Ida's moon was discovered in data played back and
analyzed in February and March 1994.
Galileo executed its other asteroid flyby--of the rocky body
Gaspra--on Oct. 29, 1991.
###
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | JPL/Telos |
___| | | | |__) |/ | | |__ Galileo S-Band | If you follow the herd, you
/___| | | | ___/ | |/__ /| Pasadena, CA | will eventually end up in the
|_____|/ |_|/ |_____|/ | slaughter house.
|
| 560.931 | More Ida moon images available | MTWAIN::KLAES | Keep Looking Up | Tue Jun 28 1994 21:16 | 127 |
| From: US4RMC::"Admin@ccmail.Jpl.Nasa.Gov" "MAIL-11 Daemon" 27-JUN-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: JPL/New Galileo Ida moon images available
NEW GALILEO ASTEROID MOON IMAGES AVAILABLE
The highest-resolution images of the recently discovered moon of
the asteroid Ida taken by NASA's Galileo spacecraft have been released
by the space agency.
The images include a higher-resolution version of a picture of
the asteroid moon released in March 1994. The illuminated and dark
parts of the moon are shown in separate pictures.
The pictures were taken by Galileo as it flew by the asteroid on
August 28, 1993, and were played back by the spacecraft in early June 1994.
The image files are:
IDAMNHI.GIF 25K Highest-res Galileo image of Ida moon P-44297
IDAMN1ST.GIF 31K Galileo's first glimpse of Ida moon P-44298
The files are available online via the following methods:
-- By Internet using the World Wide Web system, they may be
accessed from JPL's home page at the address http://www.jpl.nasa.gov,
under the feature "News flashes."
-- By Internet using anonymous file transfer protocol (ftp) to
the address jplinfo.jpl.nasa.gov (137.78.104.2); the files are in the
directory `news.'
-- Users with a computer and modem may call +1 (818) 354-1333;
the files are in the directory NEWS.
The files' captions are appended to this announcement.
_____________________________________________________________________
idamnhi.gif:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
PHOTO CAPTION P-44297
June 27, 1994
This image is the most detailed picture of the recently
discovered natural satellite of asteroid 243 Ida taken by the
Galileo spacecraft's solid-state imaging camera during its
encounter with the asteroid on August 28, 1993. Shuttered
through the camera's broadband clear filter as part of a 30-frame
mosaic designed to image the asteroid itself, this frame
fortuitously captured the previously unknown moon at a range of
about 3,900 kilometers (2,400 miles), just over 4 minutes before
the spacecraft's closest approach to Ida. Each picture element
spans about 39 meters (125 feet) on the surface of the moon.
More than a dozen craters larger than 80 meters (250 feet) in
diameter are clearly evident, indicating that the moon has
suffered numerous collisions from smaller solar system debris
during its history. The larger crater on the terminator is about
300 meters (1,000 feet) across. The satellite is approximately
egg-shaped, measuring about 1.2 by 1.4 by 1.6 kilometers (0.75 by
0.87 by 1 mile). At the time this image was shuttered, Ida was
about 90 kilometers (56 miles) away from the moon, outside this
frame to the left and slightly below center. This image was
relayed to Earth from Galileo on June 8, 1994.
The Galileo project, whose primary mission is the exploration of
the Jupiter system in 1995-97, is managed for NASA's Office of
Space Science by the Jet Propulsion Laboratory.
#####
_________________________________________________________________
idamn1st.gif:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
PHOTO CAPTION P-44298
June 27, 1994
Within seconds of its closest approach to the asteroid 243 Ida on
August 28, 1993, the Galileo spacecraft's solid-state imaging
camera caught this glimpse of Ida's previously unknown moon
orbiting the asteroid. One frame of a 15-image set designed to
capture a view of Ida at the highest possible resolution landed
by chance with its edge right on the little moon. The range from
the spacecraft was about 2,400 kilometers (1,500 miles), and each
picture element spans about 24 meters (80 feet) on the surface of
the moon.
Only a small sliver of the sunlit crescent is visible at the edge
of the frame, which was shifted inward toward the center in this
representation. Ida itself is outside this frame to the left and
slightly below center, roughly 90 kilometers (56 miles) away.
The dark side of this moon is illuminated by light reflected from
the sunlit side of Ida, in the same way that Earthshine brightens
the dark part of Earth's moon when it shows only a thin sunlit
crescent, near "new moon". The smoothly curving shape of the
dark edge Ida's moon can be seen on the left. The asteroid
moon's observed dark side was just barely detectable by Galileo's
camera; computer enhancement has made it easier to see in this
picture. The visibility of the moon's dark limb has provided
valuable information on the size and shape of the tiny moon,
which measures about 1.2 by 1.4 by 1.6 kilometers (0.75 by 0.87
by 1 mile).
The little moon's relatively smooth egg shape contrasts markedly
with the highly irregular shape of its parent, the asteroid Ida.
This image was relayed to Earth from the Galileo spacecraft on
June 8, 1994.
The Galileo project, whose primary mission is the exploration of
the Jupiter system in 1995-97, is managed for NASA's Office of
Space Science by the Jet Propulsion Laboratory.
|
| 560.932 | July 1 | MTWAIN::KLAES | Houston, Tranquility Base here... | Fri Jul 01 1994 16:53 | 45 |
| From: US4RMC::"Admin@ccmail.Jpl.Nasa.Gov" "MAIL-11 Daemon" 30-JUN-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: Galileo status 7/1/94
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
July 1, 1994
The Galileo spacecraft is now 246 million kilometers (153
million miles) from Jupiter, and in about two weeks it will begin
observing the impact of Comet Shoemaker-Levy 9 with the night
side of Jupiter.
Galileo will be the only observer in a position directly to
image the impact sites, which will be out of view of Earth until
some time after the impacts. The data will be recorded on the
spacecraft's onboard tape recorder for later transmission to
Earth. Galileo's camera, near-infrared mapping spectrometer,
ultraviolet spectrometer, photopolarimeter radiometer and plasma
wave instrument will collect data during various impact events.
Galileo completed its playback of data from the August 1993
encounter with the asteroid Ida -- and its discovery of Ida's
moon -- late in June, and high-resolution images of the moon were
processed and published.
In July 1995 the spacecraft will release the Jupiter
atmospheric entry probe. From that point, the orbiter and probe
will fly independently to Jupiter. On December 7, 1995, the
probe will enter the atmosphere and relay its data to the
orbiter, which will maneuver into an orbit around Jupiter that
day. The orbiter will then collect data about Jupiter, its major
satellites and the magnetosphere for the next two years.
The Galileo spacecraft is operating normally, spinning at
about 3 rpm and transmitting data at 10 bits per second. It is
moving toward its rendezvous with Jupiter at a speed (relative to
the Sun) of about 10.4 kilometers per second (23,400 mph).
|
| 560.933 | | HELIX::MAIEWSKI | | Fri Jul 01 1994 17:22 | 13 |
| So is there any word anywhere on what, if anything, is going on with the High
Gain Antenna?
Last I heard, (last winter or the one before, I forget), they were doing
heating and cooling turns. They were convinced that the pins were binding and
that they could be released. Then they tried that "hammer" move with the motor
and suddenly we didn't hear another word about the HGA.
Can we assume that they gave up?
Is there any sort of final theory as to why it's stuck?
George
|
| 560.934 | | PRAGMA::GRIFFIN | Dave Griffin | Fri Jul 01 1994 21:21 | 32 |
| The HGA is stuck, and stuck bad. The mission has been replanned
to run without the HGA.
The various heating and cooling turns did not solve the problem (I'm
not sure anyone was "convinced" that any procedure would fix the
defect, but they had varying levels of optimism).
Hammering went through various phases (changing the frequency and
duration of the cycles). No significant changes.
Last I heard, another round of trials will be done (probably without
fanfare) only because it is worth the try -- but now good luck is
all they are expecting. In a sense, yes, they have given up
(as far as intense analysis, more experiments, etc.).
The only theory I have heard that had any longevity to it is probably
articulated much better somewhere in this note: lubrication on the
center pole was worn out due to the various trips between JPL and KSC
before it flew in '89 -- the antenna bound up on one area. There
is/was some speculation that the trip in and around Venus didn't help
matters here at all -- possibly evaporating (or whatever) additional
lubricant or possibly deforming the structure in some other manner.
[Please remember that Galileo was not designed to head *closer* to the
sun, and had additional covers, etc placed on it during that early part
of the VEEGA orbit. Opening of the HGA had to be delayed because of
this trajectory change, and the design probably failed to fully account
for all the environmental changes.]
- dave
|
| 560.935 | August 1 | MTWAIN::KLAES | Houston, Tranquility Base here... | Mon Aug 01 1994 20:07 | 54 |
| From: US4RMC::"Admin@ccmail.Jpl.Nasa.Gov" "MAIL-11 Daemon" 31-JUL-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: Galileo status 8/1/94
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
August 1, 1994
The Galileo spacecraft captured an extensive range of data
on the impacts of the fragments of Comet Shoemaker-Levy 9 on
Jupiter July 16 through 22. Because of its position 240 million
kilometers (150 million miles) from Jupiter and in the direction
of the impact sites on the planet's night side, Galileo was able
to make unique direct observations of the impact events which
were not visible from Earth.
The data from Galileo's science instruments were stored on
the spacecraft's onboard tape recorder. Science teams are now
carefully evaluating data stored on tape to select portions to be
transmitted to Earth starting in August.
The spacecraft's photopolarimeter-radiometer has already
obtained and transmitted light-intensity readings from the
impacts of comet fragments H, L and Q on Jupiter's far side. The
B impact did not produce a significant indication; data from
fragment P was recorded on tape for later playback.
Engineering telemetry indicated that Galileo's computer
directed the imaging system, the near-infrared spectrometer, the
ultraviolet spectrometer and plasma wave instrument to observe
the impacts as planned. The camera observed the fragment D, E,
K, N, V and W events, the infrared instrument the C, F, G and R
impacts. Their observations are stored on tape, intended for
gradual transmission to Earth beginning this month and continuing
through January 1995.
The spacecraft continues to operate normally, spinning at
about 3 rpm and transmitting at 10 bits per second to ground
stations of the NASA/JPL Deep Space Network. Galileo is about
640 million kilometers (400 million miles) from Earth, so that a
command takes 36 minutes to reach Galileo, and the response
another 36 minutes to return. The spacecraft will reach Jupiter
on December 7, 1995, when its probe will descend into the Jovian
atmosphere and the orbiter spacecraft will begin two years of
observation and measurement of the planet, its moons and magnetosphere.
#####
|
| 560.936 | Why no relay satellite and the fixes | MTWAIN::KLAES | No Guts, No Galaxy | Wed Aug 03 1994 21:06 | 87 |
| Article: 3942
Newsgroups: sci.astro,alt.sci.planetary
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Galileo - why not send a re-transmitter?
Date: Mon, 1 Aug 1994 05:00:56 GMT
Organization: U of Toronto Zoology
In article <31hp3d$n1e@news.u.washington.edu> aberman@u.washington.edu
(Andrew Berman) writes:
>How much would it cost to send something out to Jupiter that does
>nothing but collect Galileo's data and re-transmit it with a more
>powerful antenna? The craft would be far less complicated than
>the Clementine mission, so the cost would mostly be in the propulsion,
>right?
Even that would not be a grave problem, actually. Remember that
Galileo took a rather roundabout path to Jupiter. A relatively small
relay satellite could have been launched on a much more direct
trajectory, at about the time of Galileo's second Earth flyby.
There was serious talk of doing this. The major problem was that it
required fast action -- a significant lump of funding inserted into
NASA's budget plans *immediately* -- and NASA just is not geared to do
that kind of thing. The political difficulties involved in getting
rapid funding, even of a rather modest amount, were formidable. The
death blow was the development of a strategy to preserve a good bit of
the Galileo science return without a relay satellite. Given that, the
political support needed to push the relay satellite funding through
in a hurry just wasn't there.
--
"We must choose: the stars or the dust.| Henry Spencer @ U of Toronto Zoology
Which shall it be?" -H.G.Wells | henry@zoo.toronto.edu utzoo!henry
Article: 3976
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.astro,alt.sci.planetary
Subject: Re: Galileo - why not send a re-transmitter?
Date: 2 Aug 1994 15:31 UT
Organization: Jet Propulsion Laboratory
In article <wa2iseCtvI19.AvA@netcom.com>, wa2ise@netcom.com (Robert
Casey) writes...
>I think that NASA spent some money upgrading the recieve sites on Earth
>to help increase data thruput. Making the recieving antenna bigger
>helps compensate for a weak transmitter out in space. And you get to
>use those bigger recieve dishes on the ground for other probes or
>do some radio astronomy. I think they did this for Voyager's Neptune
>encounter, and borrowed the use of a big radio astronomy site during
>the encounter. I suppose NASA could do that again for Galileo.
To maximize the data output from Galileo using the Low Gain Antenna,
the following enhancements will be performed. The software onboard
the spacecraft will be modified in the two computers (CDS and AACS) to
add algorithms to compress images and to implement changes in the
error correction codes. The Deep Space Network (DSN) will be
augmented to array multiple antennas, add new error-correction codes,
allow for frequent changes in the data rate and to provided the
capability to recover most of the data during periods of acquisition
and reacquistion. Also, an S-Band Ultracone will be installed in the
70-meter antenna at Canberra to provide a lower System Noise Temperature.
Without these enhancements, Galileo will only be able to trasnsmit
from Jupiter at 10 bits/second. Once the enhancement are in place,
the bit rate will vary between 8 bps to 160 bps, depending on the
distance to Earth, which DSN station is tracking, and which antennas
are being arrayed. The bit rate will be changed from 6 to 8 times
during a typical 24 hour DSN tracking pass. The 160 bps rate is
achieved when the signal from the Madrid 70-meter antenna is arrayed
with the three Madrid 34-meter antennas and the 70-meter Goldstone
antenna.
Assuming an image compression of 10, the "effective" bit rate will
range from 80 bps to 1600 bps.
The Parkes antenna in Australia was only recently included into the
DSN array for this task, and will increase the overall data return by
10% to 20%.
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | JPL/Telos |
___| | | | |__) |/ | | |__ Galileo S-Band | You cannot achieve the
/___| | | | ___/ | |/__ /| Pasadena, CA | impossible without attempting
|_____|/ |_|/ |_____|/ | the absurd.
|
| 560.937 | September 1 | MTWAIN::KLAES | No Guts, No Galaxy | Thu Sep 01 1994 20:40 | 45 |
| Article: 6335
From: Admin@ccmail.Jpl.Nasa.Gov
Newsgroups: sci.space.news
Subject: Galileo status 9/1/94
Date: 1 Sep 1994 10:57:14 -0700
Organization: Jet Propulsion Laboratory - Pasadena CA
Sender: daemon@news.arc.nasa.gov
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
September 1, 1994
Galileo's first images of the July impacts of comet
Shoemaker-Levy 9 on Jupiter were released during August. These were
partial photometric scans of the fragment K event and a four-image
sequence of the arrival of fragment W. This week the team is
concluding a long-planned series of engineering activities, including
preparations for software changes that will ready the spacecraft for
its Jupiter approach, atmospheric probe entry and relay, and orbit
insertion activities late next year.
On September 9, the Galileo flight team will transmit the next
operating sequence to Galileo, commanding the spacecraft to resume
transmitting Shoemaker-Levy data stored on Galileo's onboard tape
recorder. This will continue, with an interruption for solar
conjunction, through January 1995. The transmissions may include more
views of fragment W and more photometric scans on fragment K.
Scientists will also be seeing infrared, ultraviolet and photometric
data on the very large fragment G impact, permitting comparison with
Earth-based observatory measurements.
Galileo is now 708 million kilometers (440 million miles) from
the sun, a distance increasing by more than 400,000 kilometers (a
quarter-million miles) each day. It is 222 million kilometers (138
million miles) from Jupiter, and a little more than 15 months from
arrival at the giant planet. The spacecraft is operating normally,
spinning at about 3 rpm, transmitting at 10 bits per second.
#####
|
| 560.938 | Making sacrifices to save the mission | MTWAIN::KLAES | No Guts, No Galaxy | Wed Sep 14 1994 20:37 | 172 |
| Article: 3405
From: steven@igor.Levels.UniSA.Edu.Au (Steven Pietrobon)
Newsgroups: sci.space.tech
Subject: Re: Galileo questions
Date: 9 Sep 1994 02:06:23 GMT
Organization: Co-operative Research Centre for Sensor Signal and
Information Processing.
Richard Keaney (richardk@mpce.mq.edu.au) in article
<34ekk7$1vs@sunb.ocs.mq.edu.au> writes:
> I have several questions regarding the Galileo space probe mission:
>
> 1) Is there any hope of the high gain antenna being freed, or have all
> of the proposed manoeuvres to unstick it been tried and failed?
The one last hope is that the action of firing the retrorocket to put
Galileo into orbit around Jupiter (provided that the propellant tanks
successfully pressurise after over six years in space) will provide
enough vibration and force to shake the antenna free. I think that
Galileo will also be spun up more than usual to provide a little extra
force on the antenna during the orbit insertion burn.
> 2) Why is the data rate from the low gain antenna so low, and what causes it
> to vary from 10 to 40 bit/s? Is this is power budget limitation?
The data rate changes are due to varying distance between Galileo and
the Earth. Galileo is currently near the apogee of its orbit and is
moving fairly slowly. When the Earth is closest to Galileo, the rate
increases to 40 bit/s and when the Earth is furthest (about 6 months
later) the data rate drops to 10 bit/s. At its current distance I
think that only 10 bit/s can be managed despite where the Earth is.
The data rate is so low because the Low Gain Antenna (LGA) is an
omnidirectional antenna. The LGA was meant only for commanding and
receiving some telemetry data from Galileo when the High Gain Antenna
(HGA) wasn't pointed at the Earth.
> 3) Do the links using the low gain antennae employ the same forward error
> correction coding as that proposed for the high gain link (ie rate 1/4 K=15
> convolutional coding) or is some other FEC scheme employed?
The Low Gain Antenna (LGA) has the standard (2,1,6) convolutional
code, with polynomials
133 171
hard wired to the LGA and could not be switched out (what a mistake
that was). To get a more powerful inner code they concatenated a
(2,1,10) code with the (2,1,6) code to obtain a (4,1,13) code. The
(2,1,10) code has polynomials
3403 2423
and the concantenated (4,1,13) code has polynomials
26042 36575 25715 16723
This is a really weird code as the distance leaving and entering a
state is 3 instead of 4 which slightly reduces the performance of the
code. That's the price that is paid for hard wiring the (2,1,6) code.
I'm not exactly sure how the (2,1,10) code was found, but I was told
that it was not found by an exhaustive search due to lack of time. The
size of 13 was chosen by some dumb software engineers who said they
could only implement a (2,1,10) code. They later found out that could
have done a (2,1,11) code but by then the code was set in concrete and
couldn't be changed.
The Reed Solomon outer code is of length 255 using GF(2^8) arithmetic.
The number of parity bytes is varied in the pattern
(94,10,30,10,60,10,30,10) giving an average rate of 223.25/255. The
concatenated code still performs pretty well as they can get an Eb/No
of 0.6 dB at a BER of 1e-7 using iterative decoding. At Jupiter this
gives a maximum data rate of 100 bit/s when all the best antennas on
Earth are used. Normally though, the rate will drop to about 50 bit/s
due to non-ideal antenna arrangements. The new (255,223.25) RS encoder
and (2,1,10) convolutional encoder will be implemented in software
using one of the computers on Galileo. Due to the large software
change this will require, the data from the atmospheric probe will be
sent at 10 bit/s for several months. When all the atmospheric probe
data has been successfully received (and this may take several
transmissions) the new software will be sent up and the higher data
rate achieved.
The decoding for the LGA data will be performed using several
workstations working in parallel. I got a lot of the above information
from talking to some engineers who worked on the LGA mission so some
of it may be incorrect.
Steven S. Pietrobon, Australian Space Centre for Signal Processing
Signal Processing Research Institute, University of South Australia
The Levels, SA 5095, Australia. steven@spri.levels.unisa.edu.au
Article: 3407
From: James.C.Marr-IV@jpl.nasa.gov (jim marr)
Newsgroups: sci.space.tech
Subject: Re: Galileo questions
Date: Fri, 09 Sep 1994 09:51:15 -0800
Organization: JPL
In article <8SEP199416214115@kelvin.jpl.nasa.gov>,
baalke@kelvin.jpl.nasa.gov (Ron Baalke) wrote:
> In article <34ekk7$1vs@sunb.ocs.mq.edu.au>, richardk@mpce.mq.edu.au
(Richard Keaney) writes...
> >I have several questions regarding the Galileo space probe mission:
> >
<snip>
> >3) Do the links using the low gain antennae employ the same forward error
> >correction coding as that proposed for the high gain link (ie rate 1/4 K=15
> >convolutional coding) or is some other FEC scheme employed?
>
> The same coding algorithms are being used (14, 1/4 convolutional). A
> four-level Reed Solomon error correction will be added in.
Ron's almost right. The Galileo currently uses a rate 1/2, constraint
length 7 (i.e. a (7, 1/2) ) convolutional encoder (the NASA standard)
that is implemented in hardware within the Telemetry Modulation Unit
(TMU) of the spacecraft's (S/C's) Modulation Demodulation Subsystem
(MDS). The new Galileo software which is being developed for load
onto the S/C for the Orbital Tour portion of the mission, which occurs
after Jupiter Orbit Insertion (JOI), will include an additional (11,
1/2) convolutional encoder implemented in software within the Command
and Data Subsystem (CDS) and which operates on the data after it has
been Reed-Solomon encoded (as described above by Ron) but before being
sent through the MDS hardware encoder. The result of combining the
software (11, 1/2) encoder and the hardware (7, 1/2) encoder is the
(14, 1/4) code mentioned by Ron.
Thus, the S/C will operate (as it has since launch) with (7, 1/2)
encoding up until the Orbital Operations software is loaded in roughly
March 1996, after which time it will operate with the Reed-Solomon
outer code followed by the (14, 1/4) inner code for the remaining 2
years of the nominal mission.
This more elaborate coding scheme is required to keep the downlink bit
error rate below 10E-7 which is needed to allow recovery of the
compressed data (also a new S/C capability) since bit errors within a
block of compressed data make the whole block unrecoverable.
-Jim james.c.marr@jpl.nasa.gov
Article: 3417
From: fcrary@rintintin.Colorado.EDU (Frank Crary)
Newsgroups: sci.space.tech
Subject: Re: Galileo questions
Date: 10 Sep 1994 03:23:02 GMT
Organization: University of Colorado, Boulder
In article <james.c.marr-0909940951150001@137.78.212.100>,
jim marr <James.C.Marr-IV@jpl.nasa.gov> wrote:
>Ron's almost right. The Galileo currently uses a rate 1/2, constraint
>length 7 (i.e. a (7, 1/2) ) convolutional encoder (the NASA standard) that
>is implemented in hardware within the Telemetry Modulation Unit (TMU) of
>the spacecraft's (S/C's) Modulation Demodulation Subsystem (MDS). The new
>Galileo software which is being developed for load onto the S/C for the
>Orbital Tour portion of the mission, which occurs after Jupiter Orbit
>Insertion (JOI), will include...
An important side note here is that these changes will take some time
to upload and verify through the low-gain antenna. The change means
that we are going to loose most of the G1 orbit (the first after the
J0/JOI orbit.) That has a very negative impact on the science. For
example, a period of observation during the outbound leg of G1 would
be one the most favorable ones for many of the particles and fields
instruments. We are going to have to sacrifice this and live with the
somewhat less valuable but similar period of the G2 orbit.
Frank Crary
CU Boulder
|
| 560.939 | Ida's moon gets a name | MTWAIN::KLAES | No Guts, No Galaxy | Wed Sep 21 1994 19:15 | 90 |
| From: US1RMC::"DHILL@pao.hq.nasa.gov" "HILL, DIANNE" 20-SEP-1994 19:23:17.04
CC:
Subj: 94-158 ASTEROID MOON DISCOVERED BY GALILEO SPACECRAFT IS NAMED
Douglas Isbell
Headquarters, Washington, D.C.
September 20, 1994
(Phone: 202/358-1753)
James H. Wilson
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-5011)
RELEASE: 94-158
ASTEROID MOON DISCOVERED BY GALILEO SPACECRAFT IS NAMED
The International Astronomical Union (IAU) has approved the
name Dactyl for the tiny moon discovered this year in orbit
around the asteroid Ida by NASA's Galileo mission.
The IAU also approved names for surface features on another
asteroid, Gaspra, which became the first asteroid ever visited by
a spacecraft when Galileo flew by it on Oct. 29, 1991.
Dactyl is the first natural satellite of an asteroid ever
discovered and photographed. The tiny moon, about one mile (1.5
kilometers) across, appeared in images obtained by the Galileo
spacecraft during its flyby of the asteroid on Aug. 28, 1993.
Dactyl was discovered in data analyzed in March 1994 by
members of Galileo's imaging and infrared science teams. The
project recommended the name to the IAU, which is responsible by
international agreement for the formal naming of Solar System bodies.
The name is derived from the Dactyli, a group of
mythological beings who lived on Mount Ida, where the infant Zeus
was hidden -- and raised, in some accounts -- by the nymph Ida
and protected by the Dactyli. Other mythological accounts say
that the Dactyli were Ida's children by Zeus.
Three regions on Gaspra were named for scientists associated
with the asteroid. Neujmin Regio was named for G. Neujmin, the
Ukrainian astronomer who discovered the asteroid in 1916. Yeates
Regio honors the late Dr. Clayne M. Yeates, who was Galileo
Science Manager and Science and Mission Design Manager until his
death in 1991. Dunne Regio was named in honor of the late
Dr. James A. Dunne, who served as Galileo Science and Mission
Design Manager until late 1992.
"Clayne Yeates and Jim Dunne both contributed immensely to
the Galileo project and to the Gaspra encounter in particular,"
said Galileo Project Manager William J. O'Neil at NASA's Jet
Propulsion Laboratory (JPL), Pasadena, Calif.
The surfaces of Gaspra and Ida are covered with impact
craters like those on Earth's Moon. Gaspra was named by Neujmin
for a resort on the Crimean peninsula. Consequently, many of the
asteroid's craters have been named for resorts and spas worldwide.
The Galileo spacecraft is on its way to Jupiter, where it
will send a probe into the atmosphere on Dec. 7, 1995, and then
go into orbit for a two-year scientific tour of the planet, its
satellites and its magnetosphere. JPL manages the Galileo
project for NASA's Office of Space Science, Washington, D.C.
- end -
NOTE TO EDITORS: Color and black and white images of Dactyl are
available to news media by faxing your request to the NASA
Headquarters Broadcast and Imaging Branch on 202/358-4333. Photo
numbers are: 94-HC-160 and 94-H-170.
NASA press releases and other information are available
automatically by sending an Internet electronic mail message to
domo@hq.nasa.gov. In the body of the message (not the subject
line) users should type the words "subscribe press-release" (no
quotes). The system will reply with a confirmation via E-mail of
each subscription. A second automatic message will include
additional information on the service. Questions should be
directed to (202) 358-4043.
% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% From: "HILL, DIANNE" <DHILL@pao.hq.nasa.gov>
% Subject: 94-158 ASTEROID MOON DISCOVERED BY GALILEO SPACECRAFT IS NAMED
% Date: Tue, 20 Sep 94 15:48:00 PDT
% Message-Id: <2E7F6742@ms.hq.nasa.gov>
% Sender: press-release-Owner@hq.nasa.gov
|
| 560.940 | | AUSSIE::GARSON | achtentachtig kacheltjes | Thu Sep 22 1994 02:36 | 3 |
| re .-1
Harumph. Well I liked Besida.
|
| 560.941 | Mission Status Dec 1/94 | TROOA::SKLEIN | Nulli Secundus | Wed Jan 04 1995 17:04 | 52 |
| From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Subject: Galileo Update - 12/01/94
Date: 12 Dec 1994 11:56:23 -0800
Organization: Jet Propulsion Laboratory
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
December 1, 1994
The Galileo spacecraft last month transmitted to Earth a new
image of Comet Shoemaker-Levy 9's collision with Jupiter last
July showing the impact of comet fragment N.
At its peak brightness, the fragment N impact was about half
as bright as the peak of the fragment K impact, or about 4
percent of the total brightness of Jupiter as seen through the
Galileo camera's methane-band filter. Preliminary
interpretations suggest that we are seeing primarily the meteor
(bolide) phase of the event and little of the ensuing fireball,
probably because this event was less energetic than others
observed by Galileo.
Other Shoemaker-Levy data stored on Galileo's on-board tape
recorder will be transmitted to Earth through January.
Data collection on the solar wind experiment is scheduled to
continue through December 28. This experiment is designed to
measure the charged-particle environment very near the Sun by
measuring the effect of those particles on the radio signal
beamed form Galileo to Earth.
As of December 1, the spacecraft has entered solar
conjunction. The Sun-Earth-spacecraft angle is about 0.2 degree,
meaning that the Sun lies almost directly between Earth and
Galileo.
Galileo continues to operate normally, spinning at about 3
rpm and transmitting at 10 bits per second to ground stations of
the NASA/JPL Deep Space Network. The spacecraft is currently 891
million kilometers (535 million miles) from Earth, and 184
million kilometers (110 million miles) from Jupiter. It will
reach Jupiter on December 7, 1995, when its descent probe will
enter into the Jovian atmosphere and the orbiter spacecraft will
begin two years of observation and measurement of the planet, its
moons and magnetosphere.
#####
|
| 560.942 | Galileo Update - 02/01/95 | BARCOD::DEUFEL | Oh Bother | Wed Feb 15 1995 01:02 | 54 |
| Article: 6896
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update - 02/01/95
Date: 10 Feb 1995 17:24:17 -0800
Organization: Jet Propulsion Laboratory
Sender: daemon@news.arc.nasa.gov
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
February 1, 1995
In January, Galileo completed its playback of the comet
Shoemaker-Levy 9 observations, including the rest of the time-
lapsed pictures of the fragment W impact, which appeared to last
about 26 seconds. The science teams have also collected and begun
to analyze data on fragment R's impact from the photopolarimeter
radiometer, infrared and ultraviolet instruments.
Starting January 30 and continuing into March, the Galileo
flight team is installing new flight software on the spacecraft in
preparation for arrival at Jupiter. Like the operating system of
a personal computer, the flight software translates commands from
the ground and from a stored flight sequence into the actions of
the spacecraft.
The new flight software will operate onboard the spacecraft
through the rest of this year and into early 1996. Some critical
maneuvers will take place during this time, including deployment
of the atmospheric probe, Galileo's approach to Jupiter and its
observations of Io and other satellites during approach, receiving
and storing the probe's transmitted data and going into orbit
around Jupiter on December 7, 1995. The flight software will
provide backup storage for probe data and increased options for
attitude control and communications, some of which will be used
before the spacecraft arrives at Jupiter. Once in orbit the same
software will operate the initial data playbacks and orbital
operations until March 1996, when even more enhanced flight
software will be installed to conduct orbital operations and data
return.
The spacecraft continues to operate normally, spinning at
about three revolutions per minute and transmitting data at 10
bits per second to the NASA/JPL Deep Space Network. Currently the
spacecraft's signals take almost 47 minutes to reach Earth and
commands take the same time to be uplinked. The spacecraft is 845
million kilometers (525 million miles) from Earth and 157 million
kilometers (97.6 million miles) from Jupiter.
#####
|
| 560.943 | Galileo Update from the Project Manager | BARCOD::DEUFEL | Oh Bother | Wed Feb 15 1995 01:02 | 256 |
| Article: 6903
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo Update from the Project Manager
Date: 12 Feb 1995 18:04:55 -0800
Organization: Jet Propulsion Laboratory
Sender: daemon@news.arc.nasa.gov
From the "Galileo Messenger"
December 1994
(The Galileo Messenger is also available on the World Wide Web at the
following URL: http://www.jpl.nasa.gov/galileo/mess35/TOC.html)
--------------------------------------------------------------------
From The Project Manager
We are now just one year from Jupiter arrival on December 7, 1995. All our
interplanetary targets of opportunity are well behind us and each was observed
with grand success. Ida data return was completed as planned in June. Galileo's
unique direct observations of Comet Shoemaker-Levy 9 fragment impacts in July
are providing invaluable additions to the Earth-based observations' data set.
The exact impact time and evolution of several of the major events have been
determined by Galileo data. Data return is now suspended for three weeks around
our December 1 solar conjunction. The balance of the planned return will be
between mid-December and the end of January. The Deep Space Network (DSN) has
captured over 98 percent of the Galileo SL9 data downlinked to date!
SL9 data return was also suspended as planned from mid-August to mid-September
to perform a check of the functionality of every memory cell in Galileo's
Command and Data Subsystem (CDS) extended memories and the Attitude and
Articulation Control Subsystem (AACS) spare memory before loading new Flight
Software (FSW) in these memories early next year. Every cell was found
functional. Ironically, just weeks later on September 13, a cell failure caused
the data return sequence to be aborted; it took two weeks to fully diagnose what
had happened and resume playback. It is encouraging that this is the first
Galileo memory cell failure; the prelaunch prediction was that quite a number of
cells would have failed by now and, accordingly, we have always had workarounds
in our plans. Now, based upon the flight experience of Galileo and Magellan, we
should see no more than a few cells fail, which should be quite tractable.
We are delighted that NASA and Australia's Commonwealth Scientific Industrial
Research Organization (CSIRO) are now proceeding to modify the Parkes 64-m Radio
Astronomy Antenna in Australia in order to include it in the DSN/Galileo S-band
antenna array for the orbital tour data return. Parkes will improve our data
return by nearly 20 percent for the orbits that most need improvement and will
contribute very substantially to the overall mission, just as it did for
Voyager.
Calendar year 1995 is the crucial year for Galileo. Beginning in February and
through mid-March, we will be uplinking the new FSW that provides backup capture
of Probe data in the CDS and vital new autonomous fault-protection algorithms.
The final checkout of the Probe will be performed next using the new software to
buffer and return checkout data.
The Probe Release is scheduled for July 13 following a week of painstaking
operations. Final prerelease Trajectory Correction Maneuvers (TCMs) for refining
the Probe trajectory will be April 12 and June 23, 1995.
On July 20, the Galileo Orbiter 400-N main rocket engine will be used for the
first time to perform the Orbiter Deflection Maneuver (ODM) that aims the
Orbiter to its required Io flyby point, which properly establishes the Orbiter's
trajectory for Relay and the Jupiter Orbit Insertion (JOI) maneuver.
In 1995, virtually all spacecraft activity will involve preparations for Jupiter
arrival. And the large majority of arrival preparation effort on the ground will
be in preparing for contingencies. If we could count on everything going as
planned, we would be nearly ready right now. The big job is to determine what
problems to prepare for and program the spacecraft to detect and correct such
problems or, if time permits, safe itself and wait for corrective commands from
the ground.
When performing the Probe Relay and Jupiter Orbit Insertion, all fault
protection must be autonomous since each of these events occurs in less than the
nearly 2-hour round-trip light time making ground interaction out of the
question without even considering think-time and commanding reliability. Our
goal is to require no ground commanding during the last 21 days before arrival
except for TCMs and setting the command loss timer. Throughout the life of the
Project, arrival contingency planning has been a continuing process. Now in the
home stretch, with five years of flight experience and some new insights to
potential vulnerabilities, we will be doing everything we reasonably can to
maximize the reliability of Relay and JOI.
In parallel with our arrival preparations, work on the orbital mission will
continue in full swing. The new Orbital Phase FSW must be completed and
thoroughly tested and detailed orbital sequences for many of the orbits
generated. We are currently facing a substantial schedule challenge to be ready
for the first orbital tour satellite encounter--Ganymede 1 (G1)--on July 4,
1996. Our Spacecraft System Testbed planning is being streamlined and the
planning staff increased to ensure our G1 readiness.
Happy holidays to the friends of Galileo everywhere and let us all look forward
to 1995 culminating in the successful arrival of Galileo at Jupiter!!!
Bill O'Neil
Project Manager
-----------------------------------------------------------------------------
Up To Date
During the last six months (June 6 to November 25, 1994), the spacecraft
finished data return from the Ida encounter, recorded and returned data from the
Comet Shoemaker-Levy 9 collision with Jupiter, continued a solar wind
scintillation experiment, attempted to free the stuck ribs on the High Gain
Antenna, and performed operational activities associated with health, attitude
maintenance, and telecommunications link characterization.
Ida Encounter
Ida science data return was completed on June 26, 1994. Overall, 98.7 percent of
the Ida science data transmitted by the spacecraft were successfully received
and processed through the ground data system during the 1994 Ida data playback
campaign.
SL9 Observations/Data Return
Please see the feature article, The Brilliant Death of Comet SL9, for a complete
summary of SL9 activities.
Dust Stream From Jupiter?
On June 25, the Galileo Dust Detector Subsystem (DDS) registered an increase in
the rate of dust impacts reminiscent of the 11 dust streams that Ulysses
detected coming from Jupiter. The particles had a mean impact speed of 17 km/s.
Observations will continue and further analysis is planned.
Solar Wind Scintillation Experiment
Data collection on the solar wind experiment is scheduled to continue through
December 28, 1994. This experiment is designed to measure the charged-particle
environment very near the Sun by measuring the effect of those particles on the
radio signal beamed from Galileo to Earth.
Routine Operations and Testing
Several routine Retropropulsion Module 10-N maintenance flushing activities were
completed. Regular science data acquisition from the Extreme Ultraviolet
Spectrometer, DDS, and Magnetometer has continued successfully in parallel with
SL9 data return, using the Command and Data Subsystem (CDS) Memory Readout (MRO)
technique. Several Data Management Subsystem conditioning activities were
performed.
Ultrastable Oscillator
Seven Ultrastable Oscillator tests were performed to verify the instrument's
health and to collect gravitational red-shift experimental data. Long-term trend
analysis is continuing.
Acquisition Sensor
The Acquisition Sensor was routinely calibrated.
EPD Motor Maintenance
Two Energetic Particle Detector motor maintenance exercises were performed,
which stepped the motor through its eight operating positions and then returned
it to the normal position (Sector 4). The motor maintenance was successfully
verified by an MRO.
Command Tests
Conjunction command tests were performed at Sun-Earth-spacecraft (SEC) angles
ranging from 10.0 to 6.0 degrees. The command modulation was turned on at the
station (DSS-63) and the spacecraft-received signal was monitored to see if the
Command Detector Unit (CDU) locked up and maintained lock. Preliminary results
show that the CDU stayed in lock throughout the tests, though further analysis
is planned.
Telecommunications
Five Block V Receiver tests were performed over DSS-14. The Block V Receiver
successfully acquired and tracked the fully suppressed carrier signal, and
flowed telemetry and Doppler data to JPL. Full Spectrum Recorder (FSR) tests
were also performed over DSS-14 and -43. A detailed test result briefing is
scheduled with the Project on December 20, 1994.
Anomaly Status
CDS Anomaly
On September 13, 1994, the Galileo spacecraft experienced its first computer
memory cell failure in five years of interplanetary flight. This corresponds to
one failed word out of about a half-million words in Galileo's aggregate
computer memories.
During development of Galileo's advanced computer memory, it was recognized that
perhaps dozens of cells would randomly fail over the eight-year mission
lifetime. Engineers have been very surprised that no failures occurred earlier!
To protect against such failures, special fault protection was included on board
the spacecraft. Immediately upon detecting the failure on September 13, the
fault-protection software executed as planned, stopping the ongoing sequence
(which was playing back SL9 science data) and reconfiguring the spacecraft
elements to a safe state.
Galileo engineers have isolated the exact location of the memory failure. In the
near term, the Project will stop using 80 bytes of memory surrounding the one
failed byte--a very small loss when compared to the almost 400,000-byte capacity
of the spacecraft central computer. The sequence team has rewritten the
background sequences, adjusting for lost time and working around the bad memory
cell. Following verification and transmission of the "new" sequence, the
spacecraft was back in full operation on September 25. Other than a small loss
of some SL9 data, the memory failure should have no long-term effects on the
Jupiter mission.
High-Gain Antenna
A special minisequence was transmitted August 26 to configure the spacecraft for
the High-Gain Antenna (HGA) motor "hammer" activity on August 29. On that day,
the HGA dual-drive motors were pulsed 1080 times in an attempt to free the stuck
ribs. Prior to this activity, the motors were last pulsed in early 1993.
Telemetry measurements indicate that the ribs are still stuck and there was no
evidence of change in the antenna configuration. A routine Star Scanner checkout
followed the hammering activity. There was no expectation that the HGA ribs
would release, but this hammering was done as a final pre-Jupiter arrival check.
AC/DC Bus Imbalance
The AC/DC bus imbalance measurements have not exhibited significant change
throughout this period.
Uplink Generation
The EJ-8 Final Sequence and Command Generation package was approved on October
10, 1994. The sequence covers spacecraft activities from October 17, 1994, to
January 30, 1995, and includes the SL9 science data return, solar wind
experiment, and Block V receiver and conjunction tests, as well as FSR and
command conjunction tests.
The Project has approved the AACS 13.0 In-Flight Load (IFL) package for command
generation. This IFL uses the time period from February 14 to 23, 1995.
Also approved was the Jupiter Orbit Encounter (JOE) Final Sequence and Command
Generation package. This sequence covers spacecraft activities from December 3,
1995, to January 3, 1996, and includes windows for the Europa and Io encounters,
Probe Relay, JOI, Probe symbol return, and Orbit Trim Maneuvers (OTMs) 1 and 2.
The Project also approved the JOCB Orbit Profile package. This orbit profile
covers spacecraft activities from May 14 to June 29, 1996. The primary activity
in JOCB is the playback of the arrival day science data (which includes the Io,
Europa, and Torus observations). It also includes windows for OTMs 4 and 5, as
well as real-time and playback collection of science data.
The Ganymede 1 (G1) Orbit Activity Plan was approved by the Project. This plan
covers spacecraft activities from June 29 to September 1, 1996, and includes
windows for OTMs 6, 7, 8, and 9, as well as a targeted encounter with G1 and
completion of Jupiter Approach (JA)/JOE science playback data.
Ground Data System
As a result of a meeting held to review the status of parallel operations, the
Mission Telemetry System (MTS) support of Galileo was fully decommitted
effective August 19, six weeks before the target date established in 1993. MTS
is the original system that supported Voyager, Ulysses, Magellan, and earlier
projects. All future telemetry operations will use the more powerful, compact,
and cost-effective Advanced Multimission Operations System/Mission Ground Data
System.
|
| 560.944 | | AUSSIE::GARSON | achtentachtig kacheltjes | Wed Feb 15 1995 03:53 | 8 |
| re .943
>Galileo engineers have isolated the exact location of the memory failure. In
>the near term, the Project will stop using 80 bytes of memory surrounding the
>one failed byte
Anyone have any theories why if the exact location is known, 80 bytes
around the dead byte will no longer be used?
|
| 560.945 | | 52331::ANDRADE | The sentinel (.)(.) | Wed Feb 15 1995 06:35 | 7 |
| re.944
Probably due to memory page sizes, if the memory page size is 80 bytes,
all they would have to do would be to add that page to some kind of
bad pages list. Insuring that noting else will allocate/use it.
Gil
|
| 560.946 | | SKYLAB::FISHER | Indecision is the key to flexibility! | Wed Feb 15 1995 15:59 | 13 |
| I assume that it was a page thing, or possibly something to do with the
structure of the memory (these 80 bytes share something or other?), but why 80?
Unless it is really 80 hex. It's a pretty unround number by computer standards!
Also, there was a bit of an implication that they had to do a lot of
reprogramming to avoid the 80 bytes in question. If it were a page issue, then
it should just be a matter of changing the page mapping.
Odd and interesting anyway. I wonder what happens if they loose a cell during
JOI? Sounds like bad news! Or maybe the fault routines somehow can start and
stop the engine autonomously (i.e. without the computer's help)?
Burns
|
| 560.947 | | RANGER::REITH | | Wed Feb 15 1995 16:10 | 15 |
| >I assume that it was a page thing, or possibly something to do with the
>structure of the memory (these 80 bytes share something or other?), but why 80?
>Unless it is really 80 hex. It's a pretty unround number by computer
>standards!
Nah, they just need to avoid reading that "card" in the stack! 8^)
Remember, this computer technology is 20+ years old and harkens back to the 80
column punchcard and the 80 character screen width days...
>Odd and interesting anyway.
Agreed.
Jim
|
| 560.948 | | AUSSIE::GARSON | achtentachtig kacheltjes | Wed Feb 15 1995 20:44 | 10 |
| re .946
(re: Losing a memory cell during JOI)
I think that previous posting did address that issue - where it makes
the point that several things *must* happen within an interval of time
less than the light round trip time and hence completely autonomous
operation is required. Needless to say I hope the fault handling stuff
that they will be putting in place precisely for this only ever gets
"tested" on the ground!
|
| 560.949 | | SKYLAB::FISHER | Indecision is the key to flexibility! | Thu Feb 16 1995 12:11 | 12 |
| Yes, I saw that bit about it being completely autonomous, but I juxtaposed that
in my mind with the fault routine that they apparently have now for a memory
cell failure, which seemed to stop what it was doing and go to safe mode.
I just wonder what constitutes "safe mode" when you are in the harsh radiation
environment of Jupiter and where if you stop the engine at the wrong time, you
either go flying out into the great unknown, or crashing into the King Planet or
one of its courtiers.
Not code that I would like to be in charge of writing!
Burns
|
| 560.950 | | AUSSIE::GARSON | achtentachtig kacheltjes | Thu Feb 16 1995 19:45 | 3 |
| re .949
I'ld rather be responsible for writing it than testing it. ;-)
|
| 560.951 | Galileo Prove ready to descent into Jupiter's Atmos | NETCAD::CORTES | | Thu Mar 23 1995 13:25 | 102 |
| Douglas Isbell
Headquarters, Washington, DC March 22, 1995
(Phone: 202/358-1753)
Peter Waller
Ames Research Center, Mountain View, CA
(Phone: 415/604-3938)
RELEASE: 95-34
TESTS SHOW GALILEO PROBE SET FOR FLIGHT TO JUPITER
Key operational tests of the atmospheric probe on
NASA's Jupiter-bound Galileo spacecraft have been
successfully completed, demonstrating that the probe is in
good health and ready for the first-ever descent into the
atmosphere of an outer planet this December.
The just-completed testing followed NASA's first
interrogation of the atmospheric probe in 27 months, and "it
went perfectly," said Marcie Smith, Galileo probe project
manager at NASA's Ames Research Center, Mountain View, CA.
The probe now stands ready to separate from the Galileo
orbiter spacecraft in July and then fly the remaining 50
million miles of its flight to Jupiter on a solo trajectory.
"We wanted to be sure the power system was in good
shape, and it was," Smith said, "and so were the other probe
systems."
"The recent probe tests showed that each of its three
lithium battery modules were operating normally," said
Charles Sobeck, probe engineering manager. Both
accelerometers of the atmosphere structure experiment were
normal. The sampling chamber of the Neutral Mass
Spectrometer, which will analyze the composition of
Jupiter's atmosphere, was pumped out in preparation for
descent.
"Engineers also conducted an end-to-end test of the
probe data compression system, and it worked very well,"
Sobeck said. Command systems for the two redundant data
systems worked without a flaw, as did the data return link
for the primary system.
Further data on the operation of the probe radio
receiver aboard the orbiter will be returned and analyzed in
coming weeks.
Upon its arrival at Jupiter on December 7, 1995, the
probe will make the first entry into the atmosphere of one of
the solar system's giant gas planets. This will be the most
difficult planetary entry ever attempted, with the probe
expected to reach a speed of 106,000 mph before it
encounters deceleration forces of up to 350 G's (350 times
Earth gravity) through friction with Jupiter's atmosphere.
After entry, the probe will descend about 400 miles
into the planet's complex atmosphere, making the first
direct measurements of its clouds, lightning, winds and
other features.
Jupiter is the largest planet in the solar system, with
about 300 times the mass of the Earth. The planet has its
own internal heat source, and its spectacular banded
appearance and many other active cloud features such as the
Great Red Spot make its atmosphere a topic of great
scientific interest.
NASA engineers last communicated with the probe in
November and December 1992. At that time, it was in
"excellent shape," Smith said. While the vacuum of space is
considered a safe environment for non-operating spacecraft,
"it will be six years after the batteries were built before
they get used to power the probe," she explained, "so we
wanted to check them one more time before release."
After deploying the probe, the Galileo orbiter will
change its course to pass 133,000 miles above Jupiter's
clouds, while the probe continues on and descends into the
atmosphere. The probe will radio its data to the orbiter,
which will store it for later transmission to Earth before
beginning two years of orbital-based observations of
Jupiter, its moons and its powerful magnetosphere.
"We are delighted that the probe checkout went so
well," said Galileo Project Manager William J. O'Neil of
NASA's Jet Propulsion Laboratory, Pasadena, CA. The
successful probe checkout was the first activity to be
carried out under new Galileo flight software that was
transmitted to the spacecraft in January and February,
indicating that all of the major elements of the mission are
ready for the start of its encounter with Jupiter.
The Galileo probe project is managed by NASA Ames. The
overall Galileo mission is managed by NASA's Jet Propulsion
Laboratory. The probe was built by Hughes Aircraft Co., El
Segundo, CA.
|
| 560.952 | Galileo gets a successful lobotomy! :-) | NETCAD::BATTERSBY | | Fri Mar 24 1995 13:08 | 63 |
| Article: 7070
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.news
Subject: Galileo's Flight Software Reprogrammed
Date: 14 Mar 1995 15:45:44 -0800
Organization: Jet Propulsion Laboratory
Sender: daemon@news.arc.nasa.gov
From the "JPL Universe"
March 10, 1995
Galileo Revitalizes Its Operating System on the Fly
For the past two weeks the Galileo spacecraft has been living a
new life, in the software sense.
The flight software, or operating system, for the command and
data system, along with the attitude and articulation control
system, was completely replaced during the previous 3-1/2 weeks.
The command and data system actually make up Galileo's central
computer, and attitude and articulation control orients the
spacecraft, points the scan platform, and controls the propulsion
system.
"I believe this is the first time any planetary project has
replaced its spacecraft's entire operating system during its
primary mission," said Jan Ludwinski, mission planning chief.
The new flight software is, in effect, a redesign of Galileo to
allow it to carry out the first part of its mission at Jupiter
using the low-gain antenna for communications.
The new software will be in place until March 1996, covering
such critical activities as checkout and deployment of the
atmospheric probe, the approach to Jupiter (with all necessary
trajectory correction maneuvers), Io flyby, the capture, storage
and playback of the probe's scientific data, and Jupiter orbit
insertion. It will also increase the communications and attitude
control options for the spacecraft on the way to Jupiter.
Loading and checking the computer memory loads was accomplished
from Jan. 30 to Feb. 24, although project planners had allowed
until March 13 to get it all done.
"Given the tremendous complexity, it was reasonable to expect
problems and significant delays ... It's mind-boggling that the team
loaded these computers flawlessly within a day of the nominal
plan," said Galileo Project Manager Bill O'Neil. "Everyone
involved in the process deserves the very highest praise."
Of course, the redesign began long before January. The Galileo
development office developed new computer code for the two flight
computers and the orbiter engineering team made up command
packages, with support from the sequence team, and tested them on
the Galileo Testbed before the mission control team actually sent
the software to the spacecraft. "They did the redesign in less
time than it took to do the original flight software," said Gary
Kunstmann, deputy manager of Galileo's engineering office.
On March 13, the spacecraft will begin working according to a
new flight sequence. In simplest terms, the flight sequence--or a
series of direct commands from Earth--will tell the spacecraft, day
by day and even minute by minute, what to do; the flight software
tells how to do it, bit by bit.
A year from now, when the spacecraft is in its first orbit
around Jupiter and the probe's scientific data have all been sent
to Earth, Galileo's flight team will load another new flight
software. Then the spacecraft will be able do data compression and
other advanced functions, completing its orbital operations and
maximizing the science return from the Jovian system.
###
|
| 560.953 | Galileo's jupitor probe umbilical cut last night, release tomorrow | skylab.zko.dec.com::FISHER | How may I be honest with you today?-Tuvok | Tue Jul 11 1995 13:52 | 9 |
| Galileo was sent the final command to cut the umbilical cable between the probe
and the main spacecraft yesterday, and the actual pyro firing to cut the cable
was to have happened last night. No word yet (to us) as to whether it happened
successfully, although controllers should have gotten telemetry confirmation at
about 10:30PM PDT last night.
The probe is scheduled to be released from the spacecraft tomorrow.
Burns
|
| 560.954 | Cable cut, release is tonight at 10:30 PM (PDT) | skylab.zko.dec.com::FISHER | How may I be honest with you today?-Tuvok | Wed Jul 12 1995 13:12 | 14 |
| Cable cut has been confirmed. The three temp readings from the probe (which go
through the umbilical) suddenly went to 255DN (i.e. the highest possible
reading) indicating an open circuit.
The whole thing seems a bit crude, but I guess effective. The pyro firing
drives a "guillotine" through the cable; the firing is confirmed by probe data
dropout. Of course this does not prove that the cable is COMPLETELY cut
through, but I guess they are confident that it will either happen right or not
at all.
They made no mention of turning off the transmitter during the pyro firing, btw
:-)
Burns
|
| 560.955 | I'll make a wish... | 19472::petert | rigidly defined areas of doubt and uncertainty | Wed Jul 12 1995 15:50 | 8 |
| There's a very low chance that the release of the probe will jar the
main antenna open, but I don't think anyone is counting on it. I think
they are all resigned to living with the lower transmisson rate, and
making the best of it. 'Twould be nice though. Original plan was for
about 50,000 images of Jupiter over the orbiters lifetime. Now they are
hoping to squeeze 7000 through.
PeterT
|
| 560.956 | | skylab.zko.dec.com::FISHER | How may I be honest with you today?-Tuvok | Wed Jul 12 1995 16:23 | 6 |
| In fact, they are going to try to open the HGA one more time after JOI. They
figure there is some slight possibility that the probe release, the upcoming
course correction burn or the JOI burn itself may jog something since that will
be the greatest acceleration that the probe has experienced since liftoff.
Burns
|
| 560.957 | And if it opens? | MSCDEV::BOERS | The Moscow software center | Thu Jul 13 1995 09:57 | 7 |
| I wonder what will happen if the HGA opens indeed. Would it be
operational quickly, or would they have to reload masses of
software, since they changed so much to accomodate the bandwith
limitations?
Rob
|
| 560.958 | | skylab.zko.dec.com::FISHER | How may I be honest with you today?-Tuvok | Thu Jul 13 1995 14:18 | 9 |
| A guess? They might be able to use the HGA in fairly short order. Ok, so they
compress stuff before they send it...no big deal.
But they probably would wait a bit till they have a few days of breathing room
to check out the HGA before shifting over to it. And then it would take a
longer time to replan the sequences to capture more data. Surely they would not
be able to gather more data on the first few things.
Burns
|
| 560.959 | Galileo detect a large dust storm! | HANNAH::WALL | | Wed Aug 30 1995 15:06 | 97 |
|
FROM THE:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Contact: James H. Wilson
FOR IMMEDIATE RELEASE August 29, 1995
GALILEO FLYING THROUGH INTENSE DUST
STORM ON WAY TO JUPITER
NASA's Galileo spacecraft is plowing through the most intense
interplanetary dust storm ever measured as it closes in on Jupiter
after a six-year journey to reach the giant planet, scientists report.
This is the latest and greatest of several large dust storms encountered
by Galileo since December 1994, when the spacecraft was still almost 110
million miles (about 175 million kilometers) from Jupiter. The current
storm has lasted more than three weeks. The spacecraft, launched in October
1989, is now about 39 million miles (63 million kilometers) from the planet.
Galileo will enter orbit around Jupiter on December 7, 1995.
During the current dust storm, Galileo has counted up to 20,000 particles
per day, compared to the normal interplanetary rate of about one particle
every three days, said Dr. Eberhard Grun, principal investigator on the
spacecraft's dust detector experiment.
The particles, scientists say, are apparently emanating from somewhere in
the Jovian system and may be the product of volcanoes on Jupiter's moon,
Io, or could be coming from Jupiter's faint two-ring system. The dust
particles, probably no larger than those found in cigarette smoke, may
also be leftover material from Comet Shoemaker- Levy, which impacted
Jupiter last year.
Scientists believe the particles are electrically charged and then
accelerated by Jupiter's powerful magnetic field. They have calculated
that the dust is speeding through interplanetary space at between nearly
90,000 and 450,000 miles per hour (40 and 200 kilometers per second),
depending on particle size. Even at such high speeds, these tiny
particles pose no danger to the Galileo spacecraft, scientists say.
Galileo's dust detector, one of 10 instruments on the spacecraft, is
about the size of a large kitchen colander. It counts particle impacts
and observes their direction and energy. From these measurements scientists
can estimate particle size and speed.
Grun, a scientist at the Max-Planck Institute for Nuclear Physics in
Heidelberg, Germany, also has dust detectors aboard the Ulysses spacecraft
that flew by Jupiter in 1992 on its way to study the Sun, and on the
Cassini spacecraft scheduled for launch to Saturn in 1997. His team first
discovered dust emanating from Jupiter using the Ulysses instrument in
1992.
The Galileo instrument first observed dust coming from Jupiter in June
1994. Although both Ulysses and Galileo were able to show that the dust
storms seem to come from Jupiter, the intensity and timing of Galileo's
recent storms differ from those detected by Ulysses.
Chances of understanding the nature of these dust storms are improving
since, after the onset of the current storm, Galileo flight engineers
commanded the spacecraft to collect and transmit dust data as often as
three times a day, according to Dr. Carol Polanskey, team chief for the
dust instrument subsystem at NASA's Jet Propulsion Laboratory (JPL),
Pasadena, Calif. The normal collection rate had been twice per week.
In addition, the instrument was reprogrammed in July 1994, "to take
advantage of the knowledge gained from the Ulysses experience and just in
time to observe the start of the series of storms Galileo has seen,"
said Polanskey. The reprogramming also endowed the instrument with new
data compression and other improvements, she added.
"This puts us in an excellent position to view the dust phenomena as
Galileo moves toward Jupiter," she said. "We're looking forward to
determining the source of the dust storms once we get into the Jovian
system."
When Galileo arrives at Jupiter this December, it will receive and
relay the data from the atmospheric probe, which was targeted toward
Jupiter and separated from the main spacecraft in July. Galileo will then
begin a two-year, 11-orbit survey of Jupiter, its satellites, magnetosphere
and the dust environment.
JPL manages the Galileo project for NASA's Office of Space Science.
Germany is a scientific and engineering partner in Galileo. JPL also
manages the U.S. portion of the Ulysses project, a joint effort of NASA
and the European Space Agency.
|
| 560.960 | Tape recorder problem | skylab.zko.dec.com::FISHER | I've advocated term limits for 19 years! - Rep Bob Dornan | Fri Oct 13 1995 11:46 | 51 |
| Galileo appears to have a problem with its tape recorder. Here is the press
release:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Contact: Franklin O'Donnell
FOR IMMEDIATE RELEASE October 12, 1995
GALILEO SPACECRAFT ANOMALY BEING INVESTIGATED
Engineering data returned from NASA's Jupiter-bound
Galileo spacecraft last night indicate a problem with the
spacecraft's tape recorder, project officials report.
The problem was detected shortly after Galileo took an
image of Jupiter and its major moons from 36 million
kilometers (22 million miles) away. After taking the three
images required for a color photograph to be produced, the
tape recorder used to store the data was commanded to
rewind. Data received from Galileo suggest the tape
recorder did not stop as expected after rewinding.
Galileo engineers have commanded the tape recorder to a
standby mode while they investigate further, said Galileo
Project Manager William J. O'Neil of NASA's Jet Propulsion
Laboratory (JPL), Pasadena, CA. Project engineers are
proceeding slowly and cautiously to understand the problem,
according to O'Neil, and are avoiding sending unnecessary
commands to the spacecraft. In addition to analyzing
spacecraft telemetry, engineers are working with an
identical tape recorder in a laboratory spacecraft mockup on
the ground.
Project officials say a week or more may be required
for the problem to be isolated or well-understood, but that
the spacecraft remains otherwise healthy and in contact with
controllers on Earth. "The next scheduled spacecraft
operation that we need to perform is a routine thruster
flushing in about two weeks," said O'Neil. "We want to take
the time in the interim to understand this problem in
detail."
#####
10-12-95 FOD
#9569
|
| 560.961 | not what I wanted to hear... | 19472::petert | rigidly defined areas of doubt and uncertainty | Fri Oct 13 1995 13:58 | 7 |
| So, if the tape recorder fails, and the main antenna doesn't miraculously
deploy, are we SOL on Galileo? Or is there a backup recorder?
Sigh....
PeterT
|
| 560.962 | | skylab.zko.dec.com::FISHER | I've advocated term limits for 19 years! - Rep Bob Dornan | Fri Oct 13 1995 15:35 | 14 |
| Pure guesswork and interpolation:
>tape recorder used to store the data was commanded to
>rewind. Data received from Galileo suggest the tape
>recorder did not stop as expected after rewinding.
It's not clear whether this means that they got some telemetry indicating that
the TR did not do the right thing, or if the data played back from the TR
indicated that it had wound back to the end of the tape instead of to the right
place. I hope it's the latter. (I also don't know if you can wind the TR to
specific places, but I would assume so. Otherwise tape management would be a
nightmare!
Burns
|
| 560.963 | Hopefully the TR problem is s/w | skylab.zko.dec.com::FISHER | I've advocated term limits for 19 years! - Rep Bob Dornan | Thu Oct 19 1995 14:36 | 37 |
|
This is a summary of an article titled "Galileo Recorder Jams" that appeared
on the front page of the October 16-22 issue of Space News.
o A problem was discovered with Galileo's tape recorder on October 11.
Galileo's reel-to-reel tape recorder appears to be stuck in reverse.
o The problem may turn out to be a software problem that can be fixed
from the ground.
o Without the tape recorder, only about 150 images can be returned.
o Galileo chief engineer, Matt Landano, is working with a mockup of the
tape recorder to diagnose the problem and come up with a solution.
o It appears that all of the atmospheric probe data can be stored in
memory of Galileo's computers.
o The Galileo tape recorder was built by Odetics, and this type of problem
was never seen in other tape recorder provided by Odetics.
o The same model of the tape recorder was used on the Magellan, GRO
and other spacecraft.
o Cassini will carry two digital tape recorders. Cassini was at one time
slated to carry a mechanical, reel-to-reel tape recorder, but that idea
was abandoned.
o Quotes from Bill O'Neil, Galileo project manager:
"We'd like to think it's software related. If it's hardware, it's not
very likely to be recoverable. In that circumstance, we would be
hard pressed to send back images"
"You might be surprised, but [the Galileo] people are not real down in
the mouth. They are just working hard. We just won't let anything
bring us down. So everybody is just doing everything they can to get
through this"
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ Pasadena, CA | You can never do merely
/___| | | | ___/ | |/__ /| | one thing.
|_____|/ |_|/ |_____|/ |
|
| 560.964 | | SLEEPR::MAIEWSKI | | Thu Oct 19 1995 16:18 | 3 |
| This thing is jinxed.
George
|
| 560.965 | | skylab.zko.dec.com::FISHER | I've advocated term limits for 19 years! - Rep Bob Dornan | Thu Oct 19 1995 17:55 | 3 |
| Slightly less jinxed than Mars Observer at this point, but not much...
Burns
|
| 560.966 | | SLEEPR::MAIEWSKI | | Fri Oct 20 1995 12:23 | 18 |
| Well the Mars Observer blew up, or something, in one swell foop. One minute
it looked fine, the next it was gone. That's not normally associated with a
jinx.
This thing, on the other hand, can't seem to do anything right. It's been one
problem after another since day one.
First they couldn't launch the dam thing. Then they found good thing they
couldn't, the thrusters were bad. They were replaced. Then it finally did get
off the ground and the antenna wouldn't open. Now the tape recorder. One thing
after another.
Still the probe alone makes it worth the trip and it appears all the stuff
they need to relay that data back is working. At least at the moment it is
working. Also I believe that data relay happens before they light the main
engine which was when they lost the Mars Explorer.
George
|
| 560.967 | | skylab.zko.dec.com::FISHER | I've advocated term limits for 19 years! - Rep Bob Dornan | Fri Oct 20 1995 12:52 | 14 |
| > Still the probe alone makes it worth the trip and it appears all the stuff
>they need to relay that data back is working. At least at the moment it is
>working. Also I believe that data relay happens before they light the main
>engine which was when they lost the Mars Explorer.
Actually, ME was lost when they blew the pyrovalves in preperation for firing
the engine a few days before MOI. They've already done that on Galileo. Not
but what I'm disagreeing with your jinxian assessment.
Also, I *think* that they don't relay the probe data back till after JOI, though
(1) I maybe be totally wrong and (2) there may be some quick-look data sent
back. I'll try to find out.
Burns
|
| 560.968 | | MPGS::REITH | Jim (MPGS::) Reith - DTN 237-3045 SHR3-1/U32 | Fri Oct 20 1995 13:37 | 4 |
| At the current low baudrate, it'll take a while to transmit the probe
information. I'm sure it would overlap JOI in any case.
Jim
|
| 560.969 | | SLEEPR::MAIEWSKI | | Fri Oct 20 1995 14:12 | 11 |
| I guess it will take a while but from what I've heard the probe does not
generate a large quantity of data the way a camera does. From very early on
they've been saying that the antenna problem would not impact the probe because
the quantity of data was so small.
One thing I'm wondering about is what kind of power supply the probe carries.
Seems it's making a good 4-5 month trip from the time of separation until it
arrives at Jupiter. If it's running on batteries I hope it's got one like the
pink bunny carries.
George
|
| 560.970 | | skylab.zko.dec.com::FISHER | I've advocated term limits for 19 years! - Rep Bob Dornan | Fri Oct 20 1995 15:52 | 22 |
| It is batteries, George. However, it is shut down, except for a timer ticking
away somewhere in its guts (a little 555?? :-). When the timer goes off only a
one instrument is turned on (the lightning, radio, energetic particle detector).
It takes samples, but stores them internally.
About 3 hours later, the Orbiter reaches perijove and the Probe hits the top o
the atmosphere. In two minutes it slows from Mach 75 to Mach 1 (local...I don't
know what that is in M or Kph) and releases its parachute.
Only know does the transmitter come on (if I am reading the description
correctly). It transmits for about 75 minutes before either the batteries die
or the signal gets blocked by the thickening atmosphere or something give out in
the 465K heat and 30 bar pressure. Besides, the orbiter can only listen for 75
minutes anyway, apparently due to JOI prep and/or reaching the end of the
tracking range of the probe relay antenna.
The thing I'm reading "Galileo's longest day" in "The Galileo Messenger"
available at http://www.jpl.nasa.gov/galileo/mess37/Arrival.htm, does not say
exactly when the probe data is returned on the nominal time line, but it seems
quite clear that it was INTENDED to be recorded on the TR.
Burns
|
| 560.971 | The tape recorder works (at least partially...) | skylab.zko.dec.com::FISHER | I've advocated term limits for 19 years! - Rep Bob Dornan | Mon Oct 23 1995 13:00 | 152 |
| PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
October 21, 1995
A test of the tape recorder onboard the Galileo spacecraft
conducted Friday, October 20, was successful, project officials
report. On command, the tape recorder moved and read its tape in
a normal manner.
The investigation team will now focus on developing a
conditioning plan and new constraints for use of the tape
recorder that will maximize its reliability for future
operations. "The recorder's performance has been anomalous and,
therefore, substantial new efforts must now be taken to protect
against future difficulties," said Galileo Project Manager
William J. O'Neil.
#####
****************************************************************************
The following is an earlier press release that explains more of the background
for the test whose result was (partially) announced above.
Burns
****************************************************************************
FOR IMMEDIATE RELEASE October 20, 1995
GALILEO SPACECRAFT TAPE RECORDER TO BE TESTED
Engineers will transmit a series of commands to NASA's
Jupiter-bound Galileo spacecraft today in an effort to assess the
state of its balky onboard tape recorder.
The flight team, meanwhile, was buoyed by a preliminary
assessment from Galileo's science team reporting that at least
half the mission's original scientific objectives could be
obtained in the event the tape recorder is found to be unusable.
The tape recorder, which is mainly used for onboard storage
of imaging and spectral data from Galileo's instruments,
apparently malfunctioned October 11. The problem was detected
shortly after Galileo, due to reach Jupiter on December 7, took
three consecutive images through different filters to produce a
color image of Jupiter and its major moons. The tape recorder
failed to stop rewinding as expected after recording the imaging
data. Commands were sent to halt the tape recorder, which has
since remained in a standby mode.
"For the past week, we've looked in detail both at data from
the spacecraft and from an identical tape recorder in the testbed
laboratory here," said Galileo Project Manager William J. O'Neil
at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA. "We've
identified a number of both mechanical and electrical failures in
the tape recorder system that could explain this problem. Our
efforts today and in coming days will help us determine whether
the tape recorder can be restored to operation."
Commands will be radioed to the spacecraft this afternoon to
play back a small sample of data stored on the tape recorder.
The tape-recorded data, along with engineering data reporting on
the recorder's performance, first will be stored in memory
located in Galileo's central data subsystem, then transmitted to
the receiving stations of NASA's Deep Space Network this evening.
"By early next week, we will be in a position to report the
results of our efforts to operate the tape recorder," said
O'Neil. "Successful commanding of the device would still mean
additional assessment and troubleshooting." Work concurrently
continues on a backup plan to preserve the return of imaging and
spectral data in the event the tape recorder cannot be used, he
added.
Galileo's tape recorder and the spacecraft's guidance
control computer were called into service as data compression and
storage links in a sophisticated alternative method devised to
maximize data return from Jupiter after Galileo's main high-gain
antenna failed to open properly. Loss of the high-gain antenna
meant that all spacecraft communications must be conducted at
much lower data rates through a low-gain antenna.
New techniques have been developed to edit, compress and
encode Galileo's data, including images, in the spacecraft's
computers, then store that data for playback to Earth.
Additionally, new hardware and software changes at ground
receiving stations have been installed to further increase the
amount of data transmitted from Galileo's low-gain antenna.
Project Scientist Dr. Torrence Johnson of JPL reported that
at least 50 percent of the mission's original science objectives
could still be achieved if the tape recorder is found not to be
working.
"The impact of a possible loss of the tape recorder is not
as bad as people assumed when we first heard about the problem,"
said Johnson. "Even without the tape recorder, we have an
exciting mission that allow us to address all our primary
objectives. Although the total number of pictures and spectra we
receive would be lower than with a tape recorder, we would still
have enough to do the job."
According to Johnson, among the mission's three major areas
of science investigations, it is the data return from remote
sensing instruments such as cameras and spectrometers that would
be impacted most by loss of the tape recorder. Data from these
instruments can be saved by re-routing them directly to memory
areas in the flight computer.
"The mission will still study all aspects of the Jovian
system -- Jupiter's atmosphere, its moons and its magnetic
environment -- and we plan to make a majority of the scientific
measurements that had already been planned," said Johnson.
One hundred percent of the atmospheric probe's science
objectives can be achieved without the tape recorder, in addition
to all of the Galileo orbiter's survey of the Jovian magnetic and
charged-particle environment, Johnson said.
"The principal loss of data, if the tape recorder is not
usable, would be the number of images and other high-rate
spectral data that could be returned by the spacecraft," said
Johnson. Galileo spacecraft and software engineers, however, are
devising new backup methods to store imaging and spectral data in
available memory areas within the spacecraft's central data
processor.
Preliminary assessments indicate that at least 150 to 300
high-resolution images of the Galilean moons of Jupiter and
additional hundreds of Jupiter and Io volcanoes-monitoring images
could be returned over the course of Galileo's two-year orbital
tour.
The Galileo mission consists of an orbiter spacecraft and an
atmospheric probe, which was released from the orbiter in July.
The probe will parachute into and directly sample Jupiter's
atmosphere on December 7. Its data will be radioed to the
Galileo orbiter overhead. Also on December 7, shortly after the
completion of the probe's mission, the Galileo orbiter's rocket
engine will fire to brake the spacecraft into orbit around
Jupiter, beginning a two-year detailed study of the Jovian
system.
#####
10/20/95 MBM
#9570
|
| 560.972 | | SLEEPR::MAIEWSKI | | Mon Oct 23 1995 14:19 | 14 |
| Re the Probe.
This sort of sounds like a recent episode of "this old house" where Norm
built a wall in a house starting with the baseboard. Steve kept asking "Where
are the studs, where is the dry wall? Starting with the baseboard?"
Same here, don't they have to do thing like course corrections on the probe?
Seems reentry is usually a delicate thing where if you are too shallow you
miss, too steep you burn up. Also, how they point the heat shield forward and
the parachute back without attitude control? What about electronics for the
pyros that release the parachute?
What? Starting with the baseboard?
George
|
| 560.973 | | skylab.zko.dec.com::FISHER | I've advocated term limits for 19 years! - Rep Bob Dornan | Mon Oct 23 1995 15:55 | 48 |
| > Same here, don't they have to do thing like course corrections on the probe?
Nope. It has no course-changing capabilities. They got all of Galileo on the
Jupitor-intersect trajectory that the probe wanted (minus 2 fps or so) and then
they blow the pyros to separate the probe. Springs push it away from the
orbiter (making up the 2 fps). A few days later the orbitor fires its engine to
move from the intercept to the enter orbit trajectory (the ODM or orbiter
deflection maneuver).
>Seems reentry is usually a delicate thing where if you are too shallow you
>miss, too steep you burn up.
I suspect that this is really a lot less delicate than the press made out at the
time of Apollo. Especially when you are aiming at a big thing like Jupiter and
you don't have a ship waiting for you at a specific point on the surface. I
think any landing point on Jupiter within a few million square km would be fine.
Besides it's going to blow all over heck anyway...one of the experiments is
doppler measurement of the probe signal to track the wind.
>Also, how they point the heat shield forward and
>the parachute back without attitude control? What about electronics for the
>pyros that release the parachute?
Guesswork on my part: The probe's shape has only one stable position moving
through a fluid. It is shaped like a blunt cone with a rounded base with the
heat shield on the front (pointy) end and the 'chute on the back.
About the 'chute release, perhaps .970 was a bit unclear. The timer goes off
before the probe hits the atmosphere. It turns on only a couple of science
instruments at that point, but I assume there are other mission timer things
going on. I have not been able to find out whether the 'chute is popped based
on a decelleration profile or on pure time, but regardless, the probe is alive
during the initial plunge through the atmosphere. It just does not turn on the
radio transmitter until after the chute is out.
I've also been unable to tell if we can determine anything about the probe
before it starts to transmit. The item I was reading said something about the
DSN "monitoring" the probe sequences, but I don't see that that is possible till
the probe turns on its transmitter. OTOH, I suppose it might be possible to see
the probe's plunge in some band-or-other (with HST or with Galileo's own
instruments). We've got some major plasma and light being generated there
(15,500 C, brighter than the sun's surface).
> What? Starting with the baseboard?
Sorry, I don't get this. I don't do houses :-)
Burns
|
| 560.974 | ? current status | NETCAD::BIRO | | Wed Nov 29 1995 18:09 | 4 |
| Last I knew taht Galileo should entery Jupiter orbit on the
7th of Dec. Has anyone heard any news as to Galileo status?
john
|
| 560.975 | | MPGS::REITH | Jim (MPGS::) Reith - DTN 237-3045 SHR3-1/U32 | Wed Nov 29 1995 18:56 | 7 |
| The Galileo homepage is at: http://www.jpl.nasa.gov/galileo/
it claims 7 days and 20 hours as I write this. The last status is from the
17th and says just the oxidizer and tape recorder problems are open and both
are managable.
Jim
|
| 560.976 | | skylab.zko.dec.com::FISHER | Minister of Acronyms, Holder of Past Knowledge, DNRC | Thu Nov 30 1995 15:43 | 77 |
| They now believe that the tape got stuck on one of the tape guides because of
some binder in the tape or something. This seems to be confirmed by a hunk of
bad data at just that point.
They are concerned about 2 things with the TR now:
1) The area on the tape where the capstan was spinning for umpteen
hours may have been worn and weakened. Tape breakage would be a
unrecoverable (for the TR), so would up 25 turns of tape on the hub
at that area and declared that part of the tape offlimits.
2) The tape might stick again. It failed before while attempting to
run at high speed. They got it to work at low speed. Thus, until
they can do some careful testing (not before JOI) they will only
run the tape at low speed
1) Means that they can't use the end-of-tape detector at that end of the tape
and of course, that they have less tape than expected. I have not heard
whether/if that is very important.
2) means that they will not be doing any images of Io as Galileo enters the
Jovian system, since images must be done at high speed, plus they are using
computer memory space that held the instructions for imaging Io to hold probe
data as a backup to the TR. They *will* be doing other Io experiments, though
(fields, plasma, etc I think). This is all unfortunate, since they will never
be so close to Io again (it is a high-radiation area so they don't want to go
there more than once) unless they do a suicide pass at the end of the mission.
But as far as JOI is concerned, everything is fine. We know nothing about the
probe's status, be we assume all is well. And BTW, I was informed that it is
unlikely that any big telescopes would look for the plasma trail of the probe
entering J's atmosphere because (1) the entry path is almost straight away from
us, so we would see only a cross sections, (2) it would be just barely visible
anyway, and (3) J will be too close to the sun to use Hubble at least, and maybe
others as well.
BTW, here is the schedule (times are PST [UTC-8] Earth Received Time):
Dec 7:
6:00:28 Eurpoa closest approach
10:37:41 Io closest approach
11:07:41 Configure the Galileo to receive probe data
11:31:41 Configuration complete
14:45:27 Jupiter closest approach
14:56:25 Probe entry (nominal)
14:59:24 Probe data start (nominal)
15:28:25 Relay Radio Antenna (RRA) repositioning (to keep pointing at
probe)
15:30:43 End primary probe data, start secondary data
15:38:25 Second RRA repositioning
15:48:25 Third RRA repositioning
15:58:25 Fourth RRA repositioning
16:14:25 Probe relay end (remember nominal probe mission is only 60 min)
16:14:29 RRH Power off (bye, probie...it was nice talking...)
16:16:53 RRH stow
16:38:30 Spinup to 10.5 RPM to stabilize during orbit insertion burn
17:19:25 400 Newton engine firing starts
18:08:04 Nominal end of burn (actual cutoff is calculated in real-time
based on integrating the results from an on-board accelerometer)
18:10:00 Begin party <oops, sorry, that was an editorial comment>
December 8
03:26:17 Earth occultation by Jupiter
17:52:00 Begin probe "symbol MRO"
I think the "symbol MRO" is the memory readout of actual data sent by the probe.
The quantity of this data is relatively small and is stored in Galileo's memory.
There is a bunch of other data which is also collected from the receiver...stuff
like the frequency vs time of the probe's signal (which will give them wind
velocity). As I understand it, this data is stored only on the tape recorder,
and will not be played back until Jupiter has passed behind the sun and back out
again.
Burns
|
| 560.977 | | VMSSPT::FRIEDRICHS | Ask me about Young Eagles | Thu Dec 07 1995 15:19 | 7 |
| Has anyone heard any status??
I have not been able to get to their WWW page all day.
Thanks,
jeff
|
| 560.978 | Don't think there would be that much to report just yet. Soon... | 19472::petert | rigidly defined areas of doubt and uncertainty | Thu Dec 07 1995 16:04 | 9 |
| Well, the probe is supposed to hit the atmosphere of Jupiter at 5:56PM EST,
and I believe that it is in radio silence until that time. So I doubt
we'll really hear much about it till the news tonight (and the news I
watched this morning did show a NASA animation of the entry, so I suspect
they will go into it somewhat.)
Fingers crossed.
PeterT
|
| 560.979 | How to fry electronics w/ astronomical amounts of radiation | NETCAD::BATTERSBY | | Thu Dec 07 1995 16:26 | 14 |
| I was on the JPL web page last night and it was obvious that they
were getting a lot of hits on the page. The amout of radiation that
Galileo is expected to take is astounding. It's expected to be in
the range of 35,000-40,000 rads when it passes between Jupiter and
IO, and 1,000 rads will kill a human rather quickly. The Galileo team
is crossing their fingers too that they put in enough shielding.
BTW there was a special on the Discovery Channel sunday night, and
there was also an article in the Boston Globe Science section on
Monday. I expect that maybe we'll get some more media coverage over
the next couple of days on this.
It takes 52 minutes for the telemetry to reach earth, so they won't
know immediately what happens.
Bob
|
| 560.980 | | MPGS::REITH | Jim (MPGS::) Reith - DTN 237-3045 SHR3-1/U32 | Thu Dec 07 1995 17:19 | 2 |
| I got on the page this morning just before lunch and they expected to get
status about 6pm PST
|
| 560.981 | | ERMTRD::CLIFFE | I'll warp my own space-time ... | Fri Dec 08 1995 06:28 | 10 |
| on UK news this morning :-
Probe entered the atmosphere succesfully and was transmitting data back
for about an hour until it's demise.
Galileo fired it's rockets, and now is in orbit around Jupiter.
I've also had LOTS of trouble getting WWW pages, and I'm in UK
so it's very early in the morning - here and there !.
(8.15am UK)
|
| 560.982 | A last - got through to a page ! | ERMTRD::CLIFFE | I'll warp my own space-time ... | Fri Dec 08 1995 07:02 | 34 |
| Galileo Status Report
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
GALILEO MISSION STATUS
December 7, 1995
3:15 p.m.
Radio transmissions indicate Galileo's Jupiter atmospheric probe
mission has succeeded, with confirmation that the probe signal has been
received by the orbiter as the probe began parachuting into Jupiter's
clouds.
"At 3:10 p.m. PST, we received data from the Galileo orbiter showing
the radio link between the probe and Galileo had been achieved as
planned," said Galileo Project Manager Bill O'Neil. The data we
received is a status indicator to show us that the probe was working
and that it was transmitting data to the mothership."
A sampling of data from the probe mission will start being played back
to Earth Sunday.
Galileo engineers now await the start the of the spacecraft's critical
49-minute rocket firing that will start at 5:19 p.m. PST and is
scheduled to end at 6:08 p.m. PST The engine burn will brake Galileo
and allow it to enter orbit around Jupiter for its two-year mission.
|
| 560.983 | In orbit ! | ERMTRD::CLIFFE | I'll warp my own space-time ... | Fri Dec 08 1995 07:05 | 27 |
| Galileo Status Report
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
GALILEO MISSION STATUS
December 7, 1995
6:10 p.m.
NASA's Galileo spacecraft has successfully entered orbit around Jupiter
after its six-year trip through the solar system.
Project engineers report the spacecraft's rocket fired on time at 5:20
p.m. PST and stopped after 49 minutes as planned at 6:08 p.m. PST,
enabling the spacecraft to enter orbit around the giant planet and
begin its two-year mission of scientific studies.
Launched October 18, 1989, Galileo has traveled 3.7 billion kilometers
(2.3 billion miles) in a looping path through the solar system to reach
Jupiter, which is 934 million kilometers (580 million miles) away from
Earth.
|
| 560.984 | My observatons of the live coverage on NASA Select | NETCAD::BATTERSBY | | Fri Dec 08 1995 13:31 | 27 |
| When I got home last night, NASA Select was broadcasting from
JPL live as the probe entered the Jovian atmosphere.
There were a lot of happy faces at JPL when the probe sent back
its link telemetry to the orbiter indicating it was still healthy.
Later in the evening when the Galileo orbiter gently fired its retro
rockets for the 49 minutes & something seconds, there was more joy.
They showed periodically a real time doppler shift diagram of the
telemetry as it shifted as the orbiter slowed down and entered JOI.
The real time plot started out as a straight horizontal line, and
when the rocket fired, the plot started down in a diagonal line
left to right towards a time marker where the rocket would cease
firing roughly 49 minutes later. They said that there would be probe
data sent back from the orbiter later this weekend to early next week.
One of the JPL labs they showed on-camera even had an old VT100
on a table next to a SUN workstation, and it was still being used! :-)
There was another shot of another group of engineers sitting around
another workstation that looked like a DECstation 5000.
They also mentioned that the only obvious impact of the harsh radiation
belt are that the orbiter had to travel through between Jupiter and
IO was that its star tracker went off-line for a while, but I believe
they said it recovered once the orbiter left the region of high
radiation. They also said however that the gyro platform remained rock
solid along with all the other electronics during the excursion thru
the high radiation belt area, so they were pleased to see that they had
provided sufficient shielding.
Bob
|
| 560.985 | GALILEO MISSION STATUS December 8, 1995 | ERMTRD::CLIFFE | I'll warp my own space-time ... | Mon Dec 11 1995 06:59 | 35 |
| PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF.
91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
December 8, 1995
With their spacecraft on time and on target, Galileo engineers have
canceled tomorrow's planned maneuver to fine-tune Galileo's orbital
path around Jupiter. The achieved orbit needs no adjustment.
The reduction in spacecraft velocity from the gravity effects of
yesterday's 892-kilometer (555-mile) flyby of the moon Io translates
into a savings in propellant usage for the spacecraft, said Project
Manager Bill O'Neil at JPL. It also means Galileo will carry out its
first flyby of a jovian moon, Ganymede, on June 27, 1996, a week
earlier than the July 4 flyby previously scheduled.
Transmission of data collected from Galileo's now-vaporized companion
probe will begin Sunday at 4:17 a.m. PST and continue with playbacks
from Galileo's onboard computer memory to the antennas of NASA's global
Deep Space Network through December 13. Results of quick-look analysis
of the science data received next week will be announced at a press
briefing scheduled for December 19 at 10 a.m. PST at NASA's Ames
Research Center, Mountain View, CA.
In addition to the 40 minutes of probe data stored in Galileo's
computer memory, the entire set of probe data, up to 75 minutes' worth,
was recorded on Galileo's tape recorder. That information will be
played back to Earth beginning in February following multiple returns
of all the data stored in Galileo's computer memory.
|
| 560.986 | GALILEO MISSION STATUS December 10, 1995 | ERMTRD::CLIFFE | I'll warp my own space-time ... | Mon Dec 11 1995 07:01 | 86 |
| PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF.
91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
December 10, 1995
4:20 a.m.
NASA's Galileo spacecraft, now in orbit around the planet Jupiter, this
morning began the first scheduled return of data from its companion
atmospheric probe that parachuted into the jovian atmosphere last
Thursday.
Receipt of probe data from the spacecraft began at 4:15 a.m. PST and is
scheduled to continue throughout the day.
This afternoon at the Jet Propulsion Laboratory in Pasadena CA, Galileo
scientists will check this first batch of data to assess the quality of
the information collected by the probe, said Galileo Project Scientist
Dr. Torrence Johnson.
The probe data is the first-ever direct measurement of the giant
planet's atmosphere and should reveal details of Jupiter's composition,
climate and circulation. Forty minutes of data collected by the probe
stored in the orbiter's onboard computer memory will be radioed to
Earth over the next four days and presented to Galileo scientists for
analysis. In early February, the full collection of probe data stored
on Galileo's tape recorder, up to 75 minutes' worth, will be played
back to receivers on Earth.
Preliminary analysis of the probe data will be presented at a press
briefing December 19 at NASA's Ames Research Center, Mountain View, CA.
The Galileo orbiter's mission, meanwhile, is to conduct two years of
detailed studies of Jupiter, its moons and the planet's magnetic
environment. The project is managed by JPL.
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
December 10, 1995
5 p.m. PST
Preliminary indications are that NASA's Galileo Jupiter atmospheric
probe transmitted its data to the Galileo orbiter mothership for 57
minutes during the probe's suicidal plunge into Jupiter's atmosphere
last Thursday, project officials report.
"We are all absolutely ecstatic that our tremendously ambitious,
first-ever penetration of an outer planet atmosphere has been so
wonderfully successful," said Bill O'Neil, Galileo Project Manager at
NASA's Jet Propulsion Laboratory in Pasadena, CA. "It's especially
gratifying because so many of us have worked so hard for nearly two
decades to get this first true taste of Jupiter's atmosphere."
The first scientific results from the probe data are to be presented in
a press briefing on December 19 at NASA's Ames Research Center,
Mountain View, CA. The Ames center, supported by Hughes Space and
Communications Co., was responsible for development and operations of
the atmopsheric probe and is the lead NASA center for analysis of the
probe scientific data, with Marcie Smith as probe manager and Dr. Rich
Young as probe scientist. They are leading a team of about 50
scientists who will interpret the first-ever direct measurements of
Jupiter.
The Galileo orbiter continues to perform perfectly in orbit around
Jupiter, said O'Neil. Given the spacecraft's precise targeting, he said
he expects no "orbit trim" adjustments will be required to alter
Galileo's orbital path prior to the so-called perijove raise maneuver,
the third and last burn of the spacecraft's 400-Newton main engine
scheduled for March 1996. That long-planned maneuver is designed to
lift Galileo's orbit out of the high-radiation environment of Jupiter's
charged- particle belts which could damage the spacecraft's
electronics.
|
| 560.987 | | skylab.zko.dec.com::FISHER | We're Star Fleet officers: Weird is part of the job! -Janeway | Thu Apr 04 1996 16:16 | 5 |
| They tried the final hammering of the high gain antenna, but to no avail.
Sigh.
Burns
|
| 560.988 | Galileo Status 12/10/96 | NETCAD::BATTERSBY | | Thu Dec 12 1996 15:27 | 49
|