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| Title: | Space Exploration |
| Notice: | Shuttle launch schedules, see Note 6 |
| Moderator: | PRAGMA::GRIFFIN |
|
| Created: | Mon Feb 17 1986 |
| Last Modified: | Thu Jun 05 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 974 |
| Total number of notes: | 18843 |
886.0. "Pluto Fast Flyby Project" by KACIE::DEUFEL (Daniel Allen Deufel) Mon Jan 17 1994 00:27
I didn't see a topic wrt. the Pluto Fast Flyby project. If
something exists under a different title please feel free to
move this.
Otherwise, this is the beginning of the Pluto FFB discussion.
Cheers,
-Abdul-
-----
Xref: ryn.mro4.dec.com sci.space.science:65 sci.space.tech:423
Path: ryn.mro4.dec.com!nntpd.lkg.dec.com!crl.dec.com!crl.dec.com!decwrl!nntp.crl.com!kelvin.jpl.nasa.gov!baalke
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.science,sci.space.tech
Subject: Pluto Mission Progress Report
Date: 15 Jan 1994 22:49 UT
Organization: Jet Propulsion Laboratory
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Keywords: Pluto, JPL
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This has already been submitted to Spacelink at MSFC by the Pluto Fast
Flyby project, and I'm posting it to this newsgroup. Lot of good information
here.
Ron Baalke
--------------------------------------------------------------------------
PLUTO MISSION PROGRESS REPORT: LOWER MASS AND FLIGHT TIME THROUGH ADVANCED
TECHNOLOGY INSERTION
November 9, 1993
The following paper was presented at the 44th Congress of the
International Astronautical Federation held at Graz, Austria, October
16-22, 1993.
by
Robert L. Staehle *, Stephen Brewster, Doug Caldwell, John Carraway,
Paul Henry, Marty Herman, Glen Kissel, Shirley Peak, Chris Salvo, Leon Strand,
Richard Terrile, Mark Underwood, Beth Wahl, Stacy Weinstein.
Jet Propulsion Laboratory,
California Institute of Technology
Pasadena, CA 91109 USA
&
Elaine Hansen
Colorado Space Grant Consortium
University of Colorado
Boulder, CO 80309 USA
* Robert Staehle is the preproject manager for the Pluto Mission at JPL.
ABSTRACT
A development team at the Jet Propulsion Laboratory (JPL) and other facilities
is designing a mission to send two very small spacecraft to Pluto and Charon to
complete the initial recon- naissance of our Solar System. The two probes, each
carrying four science instruments, will obtain data on both hemispheres of
Pluto and Charon in the form of visual images, infrared and ultraviolet data,
and radio science. This paper briefly describes the mission design and
spacecraft instrumentation and subsystems, and reports on the current progress
to implement advanced technology in reducing spacecraft mass and power
requirements. Cost, schedule and performance, in that priority, are the
primary design drivers. The goal of the mission is to deliver two 120 kg class
spacecraft costing less than $400M for both, on direct trajectories to the
Pluto-Charon system taking approximately 7-10 years to arrive well before the
collapse of Pluto's atmosphere and the impending polar shadow that will reduce
the global science coverage. Contract and in-house work has been in progress
to provide breadboard proof-of-concept hardware and software contributing
toward the lower mass goal. Results are reported for candidate scientific
payload instruments, a composite structure, advanced antenna, significantly
smaller electronics packaging, high efficiency thermal-to-electric converters
for the radioisotope power sources and other candidate areas for mass, power
and size reduction within strict cost limits.
MISSION BACKGROUND
Referred to as the double-planet with its satellite Charon, Pluto is the only
known planet in our Solar System that has yet to have a spacecraft encounter
reveal some of its secrets.
In 1991, artist Ron Miller created a set of ten United States postage stamps
commemorating spacecraft voyages to eight planets and Earth's Moon. The tenth
stamp in the set showed the artist's rendition of Pluto with the statement, -
PLUTO - NOT YET EXPLORED. Sending a spacecraft to Pluto was not a new idea, but
it was from this inauspicious reminder in October, 1991 that the current
mission to Pluto was born.
There have been other attempts at designing missions to visit the outer planets
including Pluto, so why hasn't Pluto been explored? The answer lies in the
fact that Pluto is the "Mount Everest" of Solar System exploration. It is the
farthest, coldest and hardest planet to get to. It was thought that with the
present technology and economic environment, the end-to-end mission would take
too long and cost too much to be successful. A mission of this scope indeed
presents many challenges.
A proposal to investigate the mission concept was accepted and funded by NASA's
Solar System Exploration Division in January, 1992.
The Outer Planets Science Working Group (OPSWG), a NASA chartered group of
leading planetary scientists, looked at small and large missions to Pluto and
reported their findings to the National Aeronautics and Space Administration
(NASA) as early as May, 1991. In subsequent meetings with NASA, OPSWG and
NASA's Solar System Exploration Subcommittee (SSES) formally endorsed the JPL
concept of a dual Pluto flyby with very small spacecraft. In April, 1992, in
response to increasing economic stresses and social concerns, Daniel S. Goldin,
NASA's new administrator, asked its members to find faster, better and cheaper
ways of doing the business of space science. NASA would need to find new ways
to produce good science for fewer dollars. Upon learning of the exciting new
Pluto mission with its tiny spacecraft, fast trajectory and attractive price
tag, Goldin gave it his enthusiastic endorsement but warned that a spacecraft
in the 164 kg mass class would most likely not receive funding. This directive
from NASA headquarters - to reduce spacecraft mass would become the driver for
adopting and developing new technologies that would enable a 100 kg class
spacecraft to do the same science as a more massive one, and to do it for less
cost to the tax payers. Some of the new technologies might then spin off into
other space missions and into the private sector providing broader benefits.
Deliveries of prototype hardware and software began in August 1993 for key
spacecraft components to achieve mass reduction goals. This permits cruise to
Pluto in less than 10 years using Titan, Proton, or the Shuttle with various
upper stages.
FY92 BASELINE AND BEYOND
The preliminary Fiscal Year 1992 baseline for the Pluto mission was designed to
return valuable global scientific data from Pluto and Charon as soon as
possible and to do it within a strict development cost cap.
Plans are to launch two spacecraft on separate vehicles in 1999 and/or 2000 on
direct trajectories to pass within ~15,000 km of Pluto and Charon in 2007-2010,
obtain scientific data and transmit that data to Earth following the encounter.
The cost cap for this mission is $400M (FY92) for the mission development.
Two spacecraft with their science payloads and mission operations from launch
through 30 days after launch appear feasible. Cost caps for mission operations
during the cruise and encounter stages have yet to be determined but will be
kept down by limiting the size of the operations crew and by not performing
cruise science. Additional costs will be incurred for the launch vehicles, the
radioisotope power source (RPS), mission operations, data analysis, and
tracking by the Deep Space Net (DSN). All NASAborne costs from the time NASA
commits to the mission until the initial data analysis is complete comprise the
life cycle cost (LCC). Prior planetary missions have typically been measured
by their development cost, excluding the launch vehicle, some portions of the
radioisotope thermoelectric generator (RTG - when flown), and all costs
incurred after 30 days post-launch. These other substantial expenditures have
typically been borne out of multiprogram accounts. Voyager 1-2 and Pioneer
10-11 development costs by the earlier accounting method were $716M and $342M,
respectively, measured in FY92 $US. This compares to the Pluto FY92 $400M
development cost cap, also for a two- spacecraft mission.
Pluto is to be among the first planetary missions to shift to a life cycle cost
accounting method, where different phases and the total are expected to be
capped. Development cost of the FY92 baseline was estimated at FY92 $363M
including 40% reserves, and the FY93 baseline total was almost identical, in
spite of changes in several amounts comprising the total.
Life cycle cost for the FY93 baseline was estimated at $1,100M, which still
compares favorably with Voyager, Galileo, and Cassini. Because of expected US
Federal budget cuts to assist in deficit reduction, the challenge now is to
bring life cycle cost substantially below FY93 $1100M, while retaining the same
science payload, increasing data return, and maintaining reliability suitable
for a decade-long mission. In a mission redesign effort begun in September,
all aspects of the mission are being reevaluated for possible savings and for
possible consequences of changes in such areas as the need for early
developmental funding, science yield, mission reliability, development costs
and schedule risk, time of flight, and value to industrial, educational, and
government agency partners.
As part of this mission redesign, cost-saving partnerships will be considered
with agencies in other countries for such mission elements as launch vehicles,
science collaboration, instruments, subsystems, and tracking.
To come to fruition, the mission must maintain an exciting science content,
early launch, and an attractive life cycle cost and cost profile during today's
fiscally austere environment. This is the challenge of our present mission
development activity, which remains funded at a level similar to the past year
to permit substantial prototype hardware and software development, reducing
cost and schedule risk when a final budgetary commitment must be made. Simply
stated, if the costs exceed that amount which Congress initially approves, the
entire effort can be expected to be canceled. NASA will choose when to submit
the Pluto mission for a "new start" at which time it will be included as a line
item in the Federal budget.
ADVANCED TECHNOLOGY INSERTION
The so-called FY92 Baseline Pluto spacecraft was designed at a mass of 165 kg,
including reserves and propellant. It was felt that this relatively
conservative design approach would benefit from more advanced technology to
perform the same functions at lower mass, shortening trip time and stimulating
new technology applications for deep space missions.
NASA's Office of Advanced Concepts and Technology (OACT) is funding research
and demonstration of new technologies that will benefit the Pluto mission in
meeting its goals. Within a process called Advanced Technology Insertion
(ATI), the mission development team in November, 1992 issued a request for
information (RFI) and invited over 1200 contacts in industry, academia, and
Federal laboratories to look at the mission constraints of cost, schedule and
reduced mass and to help identify candidate new technologies that might be
included in the conceptual design efforts. Team leaders made it clear to the
contracting companies that paper studies were not the desired product. The
team wanted proof-of-concept hardware or software showing promise that a
particular technology could be developed for incorporating into the Pluto
mission within strict cost and performance goals. Preliminary ATI work has
resulted in the delivery of the first breadboard products in August, with
subsequent deliveries through June, 1994. New technologies for the Pluto
mission will be rigorously pursued to about mid-1995 when a technology freeze
will be imposed.
The remainder of this paper illustrates specific areas in the mission
development where advanced technology is expected to show benefits. In some
cases, technology demonstration work now under contract will not produce
hardware of sufficient maturity to constitute an acceptable cost and schedule
risk for the mission within available resources. In these cases, to be decided
over the next several months, certain technologies may be left to others to
bring to flight status, as they may benefit later missions.
SCIENCE INSTRUMENTS
In April, 1992 the OPSWG defined science goals for the mission, arranging and
prioritizing them into three classes [Table 1]. The first, class 1a,
represents the "must do" science objectives for this mission. These include
the characterization of Pluto's and Charon's global geology and morphology,
surface compositional mapping, and the characterization of Pluto's neutral
atmosphere. Class 1b and 1c objectives will be attempted if still within the
project constraints.
The focused Class 1a science objectives are a marked departure from the trend
in planetary exploration over the past decades. Likewise, the science
instrument complement for this mission reflects these limitations and has
distinct similarities to earlier Mariner and Pioneer missions where the science
payload was chosen to explore specific aspects of the planet in question.
Later missions broadened the range of science addressed with a consequent sharp
rise in development time, flight time, payload complexity and cost. The
Pluto-Charon mission, with some degree of time urgency and a cost cap, has no
such luxury; payload development will require both science teams and instrument
designers to maintain a very strict discipline.
TABLE 1
Table 1: PLUTO FAST FLYBY CORE SCIENCE OBJECTIVES
(No prioritization within categories)
Category Ia
Characterize Global Geology and Morphology
Surface Composition Mapping
Characterization of Neutral Atmosphere Structure and
Composition
Category Ib
Surface and Atmosphere Time Variability
Stereo Imaging
High Resolution Terminator Mapping
Selected High Resolution Surface Composition Mapping
Characterization of Pluto's Ionosphere and Solar
Wind Interaction
Search for Neutral Species Including: H, H2, HCN,
CxHy, and other Hydrocarbons and Nitriles in
Pluto's Upper Atmosphere.
Obtain Isotope Discrimination Where Possible
Search for Charon's Atmosphere
Determination of Bolometric Bond Albedos
Surface Temperature Mapping
Category Ic
Characterization of the Energetic Particle
Environment
Refinement of Bulk Parameters (Radii, Masses,
Densities)
Magnetic Field Search
Additional Satellite and Ring Search
Because of the need to shorten flight system development time, the science
payload design must depend on technologies that are relatively mature.
However, the very ambitious mass and power allocations for the payload (7 kg,
6W) drive the design toward materials and architectures that have not been
widely applied previously in planetary exploration and for which little or no
flight experience exists.
Through a NASA Research Announcement and related Planetary Instrument
Definition and Development Program (PIDDP), "strawman" instrument components
are being developed by several teams as noted in Table 3. Achieving the
delicate balance between bold application of new technology and acceptable risk
will be a principle challenge of science payload development for the
PlutoCharon mission.
The breadboard hardware produced from the ATI effort will illustrate concepts
that employ advanced materials and electronics, novel optical arrangements,
shaped optics and highly integrated packaging. To better understand the
opportunities and implications of the adaptation of advanced materials and
architectures for the Pluto mission, a NASA Research Announcement (NRA) was
issued early in l993 for Pluto instrument concepts, the purpose of which is to
insert advanced technology into the Pluto instrument design process. The end
result of the contracts issued under this NRA will be the mitigation of risk
incurred later in the instrument development process by the inclusion of
advanced technologies, and an increased confidence that the instrument
complement necessary to achieve the science objectives can be accommodated
within the constraints of the Pluto mission.
TABLE 2
Pluto Spacecraft
BASELINE MASS COMPARISON
FY92 (kg) ATI Goal (kg) FY93 (kg)
Telecom 25.2 16.8 12.75
Electrical Power 23.2 12.5 19.4
Attitude Control 2.7 2.1 6.65
Spacecraft Data 7.0 4.5 6.5
Structure 20.0 14.6 14.6
Propulsion 20.1 13.1 9.9
Thermal Control 4.0 3.5 3.7
Science 9.0 7.0 7.0
Total 111.2 74.1 80.5
Contingency 29.5 20.1 31.3
26.5% 38.9%
Total Dry s/c 140.7 94.2 111.8
Propellant 24.6 16.1 6.9
(delta-V m/s) (350) (350) (130)
Total Wet s/c 165.3 110.3 118.7
Breadboard hardware of critical instrument elements are being fabricated much
earlier than usual in an effort to sort out the advantages and limitations of
advanced materials and technologies for their application to deep-space
planetary exploration. The experience gained will be available for application
to the flight payload development.
The most demanding element of an IR system is the detector. The most mature
detector technologies are indium antimonide (InSb) and mercury cadmium
telluride (HgCdTe or MCT). Either technology is applicable to this mission.
However, recent advances in MCT focal plane arrays (FPA) show better operating
characteristics at temperatures above those required for InSb (77 K). A higher
-operating temperature is desirable since it reduces the required size of the
focal plane array cooling radiator and therefore reduces the mass. A 256 x 256
pixel MCT array with 40 micron pixel size has been developed for use on the
Hubble telescope upgrade. This array, known as NICMOS III, would be suitable
for a Pluto IR instrument, although other larger arrays may also be available
in the timeframe required for the Pluto mission.
The degree to which all the science instruments on-board the spacecraft will
need to be combined into a single, highly integrated payload package is a
matter that should be resolved by the ATI investigations. On the one hand, the
sharing of various structural, optical and electronic elements among the
optical instruments would seem to be highly desirable to meet the mass and
power allocations and several investigators are pursuing such highly integrated
approaches. On the other hand, if the adaptation of advanced materials and
packaging techniques prove successful, mass may become less of a problem than
other factors such as compromised performance, schedule, and cost "ripple"
effects likely to arise in a highly integrated payload. If the latter factors
become the dominant consideration, then a more modular approach would be
preferable. In some cases, the adoption of an advanced material or design in
one area may result in an undesirable effect in another area. An example is
that light-weight structural material provides less radiation shielding than
say, aluminum, thereby requiring the possible addition of more shielding
material around sensitive electronic components, in turn, off-setting some of
the mass advantages of the lightweight material.
SPACECRAFT SUBSYSTEMS
The Pluto mission spacecraft has seven subsystems: Telecommunications (Radio
Frequency), Electrical Power and Pyrotechnics, Attitude Control, Spacecraft
Data, Structures, Propulsion, and Thermal Control. The spacecraft team and the
science instrument team coordinate to develop a complete spacecraft and
instrument flight system.
The design of the spacecraft has been mainly driven by three requirements
embodying cost, schedule, and performance, in that order. The first driver,
cost, is clearly the most important. If at any time during the course of the
mission development it becomes apparent to NASA that the $400M cost cap is
going to be exceeded, the Pluto mission team can expect the project to be
canceled. This not only means that the spacecraft designers must control the
cost of the spacecraft development, but that they must also cooperate with the
rest of the team to minimize the total cost. For example, it is necessary to
consider ground operations impacts in the spacecraft design to ensure that
decisions are made which reduce the combined cost of development and
operations.
The second spacecraft driver is the need to get to Pluto as quickly as
possible. This requisite stems from the OPSWG science objectives and the
implication of a short development cycle and cruise both contributing to lower
cost. Getting to Pluto faster impacts the spacecraft design in conflicting
ways. The reduced development schedule limits the use of advanced technology,
but advanced, lightweight technology could help to reduce the spacecraft mass
and shorten the flight time. A balance must be struck between development cost
and schedule, and operations cost and flight time.
The third spacecraft driver, obtaining the scientific objectives, defines the
primary function of the spacecraft. The scientific objectives of the mission
define what the spacecraft has to be capable of doing. From these objectives
come performance requirements on the spacecraft. These include electrical
power generation, data storage, communications capability, propulsive
capability, thermal control, pointing control, and a long list of other
resources or capabilities which the spacecraft must provide to the instruments.
These three drivers (cost, schedule, performance) are not independent
variables. Given the cost-schedule-performance priority for the Pluto
spacecraft, the design approach must be very sensitive to cost, and allow
capability within cost and schedule to define the performance, in this case the
science return. Science requirements and cost-driven capabilities must find a
sort of middle ground where adequate performance can be achieved for a
reasonable cost. The objectives are focused and the resulting baseline science
payload and spacecraft capability are modest; a result of cost-driven design.
>From the FY92 baseline spacecraft wet mass of 164 kg, ATI work has brought the
mass to <120 kg (wet) for the FY93 baseline (Table 2). Selection of
technologies for incorporation into each subsystem was driven by the following
criteria:
Reduce mass
Reduce power consumption
Reduce flight time
Keep cost and risk within the mission context
Level of existing activity in a technology area
TELECOMMUNICATIONS
The Telecommunications subsystem consists of a 1.5 m diameter high gain antenna
(HGA), and the radio frequency (RF) electronics. In the 1992 baseline design
the mass of the subsystem is 25.2 kg, and power consumption is 28 Watts while
transmitting. Both the transmit (downlink) and receive (uplink) signals
operate at X-band (~8 GHz). Nominal downlink rate is about 40 bits/second at
Pluto encounter range to a 34 m Deep Space Network (DSN) station. A higher
rate of ~160 bits/second is possible using the larger 70 m antennas of the DSN.
Advanced technology incorporated into the 1993 baseline includes a lighter
composite structure antenna, high density electronics packaging, and higher
efficiency RF amplifiers. These advances could reduce the mass of the
subsystem to 12.75 kg and the power consumption to 22 Watts while transmitting.
In addition, through the use of Ka-band (~32 GHz) some improvement in downlink
rate may be achieved.
A Ka-band solid state PHEMT amplifier module was constructed by Martin Marietta
Astro with substantially improved DC-to-RF efficiencies over current best
practice, measured over operating temperature range. Ka-band could speed data
return, reducing operating costs.
Advanced monolithic microwave integrated circuit (MMIC) and multi-chip module
(MCM) packaging technologies are the key to reducing the receiver portion of
the transponder mass by 50% and increasing functionality to include the Command
Detector Unit, eliminating a separate physical module. Prime power may be
reduced by elimination of unnecessary functions, intelligent frequency
planning, new device technology and the possibility of using a transceiver
versus a transponder. The latter is a navigation issue being addressed where
coherent, two-way ranging might be replaced with less precise ranging plus
greater reliance on optical navigation.
SPACECRAFT DATA
The Spacecraft Data subsystem includes the central computer and its memory, the
mass storage memory, and the necessary input/output devices for gathering data
from and commanding other subsystems. The computer executes algorithms for
attitude control, sequencing, propulsive maneuvers, fault protection,
engineering data browse and reduction, and other data management functions.
The mass memory is used to store all of the near encounter science data for
transmission to Earth post-encounter, and to store engineering data between
ground communications cycles during the entire mission. In the 1992 baseline
the subsystem had aggressive mass and power targets of 7.0 kg and 6.0 Watts
during encounter. Total science data storage volume was 400 Mbits. Use of
advanced technology in electronics packaging and low power interface drivers
allowed a small mass reduction for the 1993 baseline design while increasing
science data storage volume to as much as 2 Gbits.
ATTITUDE CONTROL
The Attitude Control subsystem includes sun and star sensing devices, an
inertial reference unit (IRU), electronics for interfacing with the central
computer in the Spacecraft Data subsystem, and electronics and switches to
drive the thrusters in the Propulsion subsystem. The star sensing device or
star camera, with its software, can determine the spacecraft's three
dimensional orientation by imaging star fields and comparing them with a
catalog of stars in the computer's memory. The sun sensors are used to help
determine orientation in the event of a star camera failure. By commanding the
small cold gaseous nitrogen thrusters in the Propulsion subsystem, the Attitude
Control subsystem can change or maintain the spacecraft's orientation. The
1992 baseline design has a mass of 2.7 kg and consumes 11.5 Watts of power.
New technology for a star tracker camera weighing <500 grams is feasible by May
1995 with a substantial development commitment now. Related star camera
activities are currently underway at Lawrence Livermore National Laboratory for
the Clementine Project and it is hoped that lessons learned there and
technologies developed can be applied to the Pluto flyby. As a reserve against
the possibility that micro star cameras may prove inadequate or difficult to
qualify for Pluto, the FY93 baseline ACS mass rose to 6.65 kg.
A Honeywell laser inertial reference unit (IRU), developed for ballistic
missile intercept vehicles, is currently on loan by Lawrence Livermore National
Laboratory to JPL for testing to Pluto mission parameters.
Additional savings in mass and power consumption are currently being
investigated in the breadboard stage elsewhere for a low- mass IRU, while test
and design qualification activities are planned for the micro star camera.
PROPULSION
The propulsion subsystem consists of a monopropellant hydrazine thruster set
for providing the required trajectory corrections, plus cold-gas thruster
attitude control equipment. A hybrid, blow- down system was adapted using a
portion of the hydrazine tank pressurant gas as the working fluid for the
cold-gas thrusters.
A tiny nitrogen gas thruster is in test to demonstrate 30,000 cycle life
required for precise control of the Pluto spacecraft orientation over a
long-term mission. 24 such 11 gm thrusters would be used, together using 1.5 kg
of gas over the entire mission.
The principal ATI objectives in the RFI were reductions in subsystem mass, gas
leakage, and power consumption. From industry responses to the Request for
Information, it became apparent that reductions in mass up to factor of five
could be realized in several components. Miniaturization of the pressure
regulators and valves (service and latch), use of a composite over- wrapped
pressurant/propellant tank as used in the fourth stage of the air-launched
Pegasus, and a surface tension propellant management device (PMD) were
identified as technologies of interest for the Pluto mission. Also identified
was a miniature (0.0045 N) cold-gas thruster with improved internal leakage
(factor of ten decrease) and cycle life (29,000 increase) specifications with a
wider operating temperature range specification. Thruster valve actuation and
holding power would also both be reduced. Based on prototype hardware
completed for Pluto, a mass reduction from 20 to 9.9 kg appears achievable.
The miniature cold-gas thruster approach meets the thrust, response time, and
minimum impulse bit requirements for the Pluto mission and the GN2 exhaust
minimizes potential spacecraft impingement problems. The ATI internal leakage
and cycle life requirements will have to be further demonstrated for the
approach to be considered a viable one.
With improvements in the injection accuracy, through 3-axis stabilization of
the upper stages, plus reductions of the rest of the spacecraft mass, reduction
in the mass of hydrazine monopropellant is possible from 24.6 to 6.9 kg.
STRUCTURE
The Structure subsystem includes the primary and secondary structure of the
spacecraft, electrical and data busses, and separation systems. The structure
must support all of the spacecraft components during the vibration and
acceleration of launch and injection by the upper stages. The structure helps
shield the electronics from the natural and RPS-induced radiation environment.
The FY92 baseline features an all aluminum primary structure with a mix of
aluminum and graphite-epoxy composite members in the secondary structure
utilizing technologies with proven procedures and processes in space
applications.
The ATI contractor delivered a composite bus structure weighing 5 kg, allowing
the structure subsystem mass to drop from 20 to 14.6 kg.
THERMAL CONTROL
This subsystem is basically passive, consisting of blankets, louvers,
radiators, and other thermal control paths and insulators. The Radioisotope
Power Source (RPS) provides heat to the delta-V thrusters and is situated to
help keep the spacecraft warm during cruise. Multilayer insulation (MLI)
blankets made from embossed Kapton (tm) or Mylar (tm) material will minimize
undesirable thermal energy transfer between elements of the spacecraft.
Thermal conduction control, such as the thermal isolation between the
spacecraft and the antenna, and thermal enhancement allowing more effective
energy conduction from the electronics to radiators that are designed to
transfer excess heat from the RPS, keep all the subsystems within tolerable
temperatures. Mechanical louvers actuated by a bimetallic device have good
radiative properties in the open position and help to hold heat in when in the
closed position. "Thermal zoning" design of the spacecraft eliminates the need
for small, separate radioisotope heater units, and minimizes the need for
controllable electrical heaters.
A composite prototype bus, designed at JPL and constructed at Composite Optics
Inc., weighs less than the aluminum baseline, carries most components inside,
and is designed in thermal zones to ease the radiation of waste RTG heat away
from the spacecraft, keep hydrazine propellant above freezing, allow
electronics to run cool, and keep sensitive detectors far enough from RTG
radiation.
In the 1992 baseline design the mass of the subsystem is 4.0 kg. Power
consumption will not exceed 1 Watt for heaters. The use of advanced
technology, like high conductivity coatings and structural materials, may help
to reduce the mass and decrease the temperature transients experienced by the
subsystems. Subsystem mass has been reduced slightly, to 3.7 kg, from the FY92
baseline.
POWER
The Electrical Power and Pyrotechnics subsystem consists of a radioisotope
power source (RPS) to generate power, power electronics for voltage conversion,
regulation, transient peak power output, switching and fusing, and pyrotechnic
device initiation (explosive bolts, pyro-valves, etc.).
The 1992 baseline design has a mass of 25.2 kg and generates 63.8 Watts of
power after 9 years of operation. Power is generated by a radioisotope
thermoelectric generator (RTG) which uses five general purpose heat source
(GPHS) modules. Power consumption of 64.4 Watts during the encounter mode
includes 20% contingency for expected power growth as the design matures.
Approximately 15 Watts is lost in DC-DC conversion and regulation inefficiency
during the highest power modes. The current best estimate for power
consumption during downlinking post-encounter (the highest power mode) is 52.31
Watts leaving a meager 22% contingency and margin within the 63.8 Watts power
capability. An additional 10% margin is needed in most modes to account for
uncertainties in the design process, the decay of the power source and the
aging of the spacecraft as a whole.
Advanced technology which was considered for the 1993 baseline design could
reduce the mass of the subsystem to ~14 kg for the same power output.
Technologies such as alkali metal thermo- electric converters (AMTEC) were
considered to dramatically increase the efficiency of the RPS, generating the
same amount of electrical power using two (GPHS) modules. A prototype AMTEC
cell producing 3W with 10% efficiency was developed and delivered to the Pluto
team at JPL. Through additional development, a 3W, 16% efficient cell is
expected to be delivered by the end of fiscal 1993. Other work is on-going
with thermophotovoltaic (TPV) converters that convert infrared radiation from
the hot surfaces of two GPHSs to electricity using low bandgap photovoltaics.
A number of lifetime and risk issues need to be resolved with TPVs before
incorporation into the baseline. To begin addressing these concerns, the Pluto
ATI program is sponsoring the first scale model demonstration of a simulated
GPHS/TPV system. Tests should be complete by the end of 1993. Both AMTEC and
TPV systems require a substantial development commitment to be available for
the Pluto project by the 1995 technology freeze date.
Because such a commitment was not possible within today's funding profile,
neither AMTEC nor TPV were selected for the FY93 baseline, in spite of
substantial Pluto ATI-funded progress. A more conservative application of
unicouple converters, as on Galileo, Ulysses and planned for Cassini, was
selected, permitting a modest mass reduction from 23.2 to 19.4 kg.
MISSION OPERATIONS
Two possible low cost approaches to Pluto mission operations are being
investigated during the ATI phase.
The first approach uses a migration of function approach by utilizing the
Voyager flight team to fly the two Pluto spacecraft as well. The Voyager team
has proven their ability to conduct successful planetary flyby operations and
would be supplemented with selected Pluto specialists in the areas of mission
planning, navigation, instruments, and spacecraft. This combined approach
would draw heavily on JPL's Advanced Multimission Operations System (AMMOS)
which is supporting current Voyager operations. The second low cost operations
approach being evaluated has been developed under a JPL contract at the
University of Colorado (CU), Boulder based on experience with Solar Mesosphere
Explorer. [11] In this approach, JPL would provide Deep Space Network (DSN)
tracking and navigation, and CU would develop a simple and unified mission
operations data system as a network of operations stations at JPL,
universities, and science investigator facilities. Many routine operations
would be accomplished by a remote-site operations team of students and
professionals with JPL experts extending the operations team for critical or
anomalous events and advising the university students. The primary, JPL-based,
control center would direct the encounter and other critical events, and each
site would serve as a backup to the other.
Additional reductions in operations costs can be realized by applying
technological advances in the development phases of the strawman instrument
package, spacecraft, mission and ground operations design that permits long
periods of unattended operations during cruise. Eight hours of tracking and
data collection per week would be made using the DSN to check up on the two
spacecraft with the following attributes:
-a spacecraft engineering data return strategy that takes advantage of on-board
data processing and analysis to minimize the amount of
engineering data that needs to be downlinked and analyzed
-spacecraft command and control capabilities that allow cruise commands to be
uplinked without simulations and elaborate constraint checking
-an encounter/flyby command sequence that is pre-planned and tested during
cruise and is only "tweaked" immediately before closest approach to allow for
mosaic retargeting and arrival time uncertainties
-capable on-board data management that permits capture and storage of all the
science data collected during flyby and allows for on-board selection,
-compression, and return over a limited downlink (40 to 160 bps) via daily DSN
passes for up to a year after the flyby
-early and continued interaction among the operations and data system design
teams, the science investigator team, and the spacecraft design team to ensure
that the Pluto mission operations and data system is specifically tailored,
developed, and evolved to meet the needs of its users at lowest possible cost
-a progressive development philosophy where the basic mission operations and
data system is developed at the start of the project; used to support prelaunch
development, subsystem test, spacecraft test, calibration, and post-launch
operations; and progressively grown to meet the needs of these project phases
and users, and
-a unified operations system architecture that facilitates the migration of
functions from the ground to space and enables trades between flight- and
ground-based functions by including both flight and ground data systems as part
of the integrated end-to-end mission operations and data system.
Further developments of a single ground data system will allow using the same
terminals and workstations which can be configured to operate either of the two
spacecraft throughout their life cycle.
STUDENT INVOLVEMENT
University students have already been involved in the initial preproject
development stages and will continue to be an important part of the Pluto team
through to the end of the mission.
Students from Caltech and other institutions built the first full- scale mockup
of the spacecraft as the very first deliverable hardware. A competition among
universities to design an adapter that unites the spacecraft to the upper stage
solid rocket motors (SRMs) was recently concluded, with students at Georgia
Institute of Technology providing the winning entry, based on Japanese/American
developments of the Institute of Space and Aeronautical Sciences. Mockups of
the upper stage SRMs with their adapters have also been delivered by students.
Visualization tools from CU and Occidental College students are currently in
production. Other student activities are summarized on Table 4.
SUMMARY AND CONCLUSIONS
A scientifically exciting initial reconnaissance of Pluto and Charon is
possible within a strict cost cap. Technologies pioneered for small Earth
orbiters, and in some cases advanced further through NASA support for the Pluto
mission, enable spacecraft mass and operations cost reductions far below what
was thought possible as little as two years ago. Present efforts are focused
on demonstrating the viability of new subsystem and instrument components, and
an innovative development, test and operations approach, through procurement
and testing of proof-of-concept hardware and software. Mission resource
constraints are being tightened even further, so recent work represents a head
start toward reaching aggressive goals of life cycle cost and technology
improvement within a first- class scientific mission to unexplored Pluto and
Charon.
ACKNOWLEDGEMENTS
The work described here was carried out at the Jet Propulsion Laboratory,
California Institute of Technology under sponsorship of NASA's Office of Space
Science and the Office of Advanced Concepts and Technology.
The authors are grateful to all the Pluto Team members and contributors, and
for the considerable assistance from their respective institutions, including
NASA Lewis Research Center, U.S. Department of Defense, U.S. Department of
Energy, Southwest Research Institute, Martin Marietta Corporation, University
of Colorado, Boulder, University of California, Los Angeles, University of
Baltimore, University of Arizona, Occidental College, Harvey Mudd College, Utah
State University and all the other organizations noted in Table 3, members of
the Technology Challenge Team chaired by Dr. Lew Allen, and the Outer Planets
Science Working Group, chaired by S. Alan Stern.
Kapton and Mylar are registered trademarks of E.I. DuPont de Nemours & Co.
REFERENCES
1. David H. Collins, "Pluto Flyby Study," Presentation to the Discovery
Program Science Working Group, (internal document), Washington, DC, 16 May
1990.
2. Robert Farquhar, S. Alan Stern, "Pushing Back the Frontier: A Mission to
the Pluto-Charon System," The Planetary Report, July/August 1990.
3. Ross M. Jones, "Small Spacecraft Activities at JPL," Utah State University
Conference on Small Satellites, Logan, Utah, August 26, 1991.
4. R.L. Staehle, D.S. Abraham, J.B. Carraway, P.J. Esposito, E. Hansen, C.G.
Salvo, R.J. Terrile, R.A. Wallace, S.S. Weinstein, "Exploration of Pluto,"
IAF-92-0558, 43rd Congress of the International Astronautical Federation,
Washington, DC., August 28 - September 5, 1992.
5. Robert L. Staehle, John B. Carraway, Christopher G. Salvo, Richard J.
Terrile, Stacy S. Weinstein and Elaine Hansen, "Exploration of Pluto: Search
for Applicable Satellite Technology," Sixth Annual AIAA/Utah State University
Conference on Small Satellites, Logan, Utah, September 21-24, 1992.
6. Robert L. Staehle, Douglas S. Abraham, Roy R. Appleby, Stephen C. Brewster,
Richard S. Caputo, John B. Carraway, Robert B. Crow, Margaret B. Easter, Paul
K. Henry, Richard P. Rudd, Christopher G. Salvo, Michael D. Taylor, Richard J.
Terrile, Stacy S. Weinstein, "Spacecraft Missions to Pluto and Charon," Pluto
and Charon, Space Science Series, University of Arizona Press, In press, 1993.
7. Glen J. Kissel, "Attitude Control for the Pluto Fast Flyby Spacecraft,"
SPIE/International Symposium and Exhibition on Optical Engineering and
Photonics in Aerospace and Remote Sensing, Orlando, Florida, April 12-16, 1993.
8. C.G. Salvo, "Small Spacecraft Conceptual Design for a Pluto Fast Flyby
Mission," AIAA-93-1003, AIAA/AHS/ASEE Aerospace Design Conference, Irvine,
California, February 16-19, 1993.
9. S. Weinstein, "Pluto Flyby Mission Design Concepts for Very Small and
Moderate Spacecraft," AIAA-92-4372, AIAA/AAS Astrodynamics Conference, Hilton
Head Island, South Carolina, August 10-12, 1992.
10. Robert L. Staehle, Stephen Brewster, Doug Caldwell, John Carraway, Paul
Henry, Marty Herman, Glen Kissel, Shirley Peak, Vince Randolph, Chris Salvo,
Leon Strand, Rich Terrile, Mark Underwood, Beth Wahl, Stacy Weinstein, "Pluto
Mission Progress: Incorporating Advanced Technology," Seventh Annual AIAA/Utah
State University Conference on Small Satellites, Logan, Utah, September 13-16,
1993.
11. E. R. Hansen, "Lowering the Costs of Satellite Operations: Lessons Learned
from the Solar Mesosphere Explorer (SME) Mission," Paper AIAA-88-0549, A 26th
Aerospace Sciences Meeting, Reno, Nevada, January 11-14, 1988.
-- End-of-File --
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ Galileo S-Band | Failure is success if we
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | learn from it.
|_____|/ |_|/ |_____|/ | Malcom Forbes
| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 886.1 | | AUSSIE::GARSON | Hotel Garson: No Vacancies | Mon Jan 17 1994 01:56 | 5 |
| re .0 Which topic?
The Pluto Fast Flyby has been discussed previously in topic 565 "Fire
and Ice" although it is my belief that "Fire and Ice" is a different
proposed mission (and no doubt now defunct).
|
| 886.2 | !what! | MAYDAY::ANDRADE | The sentinel (.)(.) | Mon Jan 17 1994 15:43 | 19 |
| The things you go tru to reduce mass in space missions, double for
this one.
Better if the mass-to-space-costs were brought down once and for all,
so that all space missions would benefit. And performance and
reliability were priotized over mass issues... !!! *only a wish*
*if only, the space shuttle costs had stayed within specs*
*if only, NASP or DC-Y got off the ground, and delivered the promised
cost savings*
*if only I was a bilionaire ... oooops, let that one slip by*
Any way, my impresion was that regardless of mass reductions the
no Pluto flyby was in the cards ? Certainly I didn't expect to see
any budget at all for it at least until the year 2000 and something!
Gil
|
| 886.3 | Deleted duplicate report | CXDOCS::J_BUTLER | E pur, si muove... | Tue Jan 18 1994 14:55 | 8 |
| Oops! I deleted the report that _used_ to be here...it was the same as
the base note.
Sorry 'bout that!
Regards,
JB
|
| 886.4 | Possible ETI message on Pluto probes | VERGA::KLAES | Quo vadimus? | Tue Jan 18 1994 15:26 | 25 |
| Article: 81429
From: jfoust@ATHENA.MIT.EDU (Jeffrey A Foust)
Newsgroups: sci.space
Subject: Re: Pluto Mission Progress Report
Date: 17 Jan 1994 07:07:00 GMT
Organization: Massachusetts Institute of Technology
In article <CJr7B6.Bny@athena.ulaval.ca> dutil@leo.ulaval.ca writes:
>Does someone want to place a SETI plate spacecraft like the Pionners and
>Voyagers?
Versions of the project plan I have seen have made mention of an
allowance for a small, light (no more than a few hundred grams) plaque
or something similar for this purpose, so long as the plaque was
provided by an outside group (i.e, JPL didn't have to pay for it).
Right now, though, that's not a concern high up the minded of the
project planners... they're more concerned about getting funding. ;-)
--
Jeff Foust
EAPS Dept., MIT | "We'll sell you a car no matter what planet
jeff@astron.mit.edu | you're from." -- from a TV ad for a used car
jfoust@mit.edu | dealership in Council Bluffs, Iowa.
|
| 886.5 | GIF images | VERGA::KLAES | Quo vadimus? | Wed Feb 02 1994 17:04 | 20 |
| Article: 82356
From: Admin@ccmail.Jpl.Nasa.Gov
Newsgroups: sci.space
Subject: JPL/Pluto Fast Flyby GIFs available
Date: 1 Feb 1994 12:52:49 -0800
Organization: Jet Propulsion Laboratory - Pasadena CA
Sender: daemon@netline-fddi.jpl.nasa.gov
The following GIF image files are available at the JPL public
access computer site:
PLUTREND.GIF 117K Pluto Fast Flyby encounter rendering P43417 2/1/94
PLUTDEV.GIF 109K Pluto Fast Flyby development model P40883 2/1/94
PLUTSIZE.GIF 52K Pluto Fast Flyby size comparison 2/1/94
The site may be accessed via Internet by anonymous ftp to
jplinfo.jpl.nasa.gov (137.78.104.2), or by dialup modem to +1
(818) 354-1333. New files are placed in the directory `news',
and then are moved in 30 to 60 days to the directory `images'.
|
| 886.6 | Update - January 1994 | VERGA::KLAES | Quo vadimus? | Fri Feb 04 1994 15:35 | 141 |
| Article: 153
From: baalke@kelvin.jpl.nasa.gov (Ron Baalke)
Newsgroups: sci.space.science,sci.space.tech
Subject: Pluto Fast Flyby Update - January 1994
Date: 4 Feb 1994 01:18 UT
Organization: Jet Propulsion Laboratory
This is forwarded with permission from Robert Staehle, Pluto Preproject Manager
-------------------------------------------------------------------
Pluto Mission Development--January Summary
Covering 1993 December 23 through 1994 January 26
Accomplishments
o Preliminary "cost" estimated of added mission risk of failure
as result of added duration. Assuming 94% total mission reliability
(i.e., probability that at least one spacecraft will complete
encounter and playback), this amounts to ~FY94$3M/year, or ~1/2 of
cruise MO&DA cost rate. This will be used along with other cost terms
in life cycle cost tradeoff analyses.
o Tentative date of May 17-18 for JPL Project Capabilities
Review (PCR), combining some of traditional System Requirements Review
(SRR) and Preliminary Design Review (PDR) activities with review of
first Flight System Testbed component results.
o Expect HQ request for Preliminary Non-advocate Review (PNAR)
to be held in June to support FY97 new start.
o Boeing delivered final report on thermophotovoltaic (TPV)
converter breadboard built for Pluto. First time TPV converter up to
1283K. Achieved component operating efficiency of 13.3% for
cell/filter arrangement, matching modeled predictions. While TPV has
been dropped from Pluto consideration, Boeing hoping to proceed using
DOE assistance, with optimized components, long duration cavity tests,
and detailed systems design for future space and commercial applications.
o Alan Stern/OPSWG chair presented Pluto mission science
rational, development status and cost summary at Solar System
Exploration Subcommittee (SSES) strategic planning workshop.
o Consideration of single spacecraft mission dropped at SSES urging.
o Alan Stern/OPSWG chair completed exploratory visit in Moscow
sounding for science interest in Pluto mission cooperation at IKI,
Moscow Aviation Institute, and Moscow State University.
o Instrument data interface options laid out, ranging from
"dumb" instruments with bit stream into spacecraft data subsystem
(SDS), to "smart" instruments with fully packetized data interface.
Former probably requires less power and mass, latter requires less
complex interface and less expensive software. FY93 baseline ("dumb"
instruments with separate science data processor) to be reevaluated in
terms of life cycle and development cost.
o Held 2 Encounter Scenario Workshops to focus on complex,
interacting spacecraft, instrument, and ground system needs. Results
after further analysis to be presented at February 22-23 OPSWG meeting.
o Pluto Team requested co-location quarters for ~49 pre-project
personnel and associated equipment and facilities next to JPL Flight
System Testbed. Preproject activity at JPL currently running ~21 FTE,
with 35 individuals @>0.2FTE.
o Inertial Reference Unit (IRU)of type provided by LLNL for
Clementine baselined for Pluto based on LLNL, Honeywell, and JPL test
data and analysis based on unit loaned to JPL by LLNL. Specific
qualification issues identified and plans in progress to address.
o Public lectures to local Explorers Post and Rancho Cucamonga
3rd-5th grade classes.
o Preliminary list of frequent NASA center, industry and
university contacts by key Pluto preproject people provided at Murray
Hirschbein's request.
o Shawn Goodman replaces Beth Wahl as Structure Subsystem
cognizant engineer. Beth took MESUR-Pathfinder position.
o Clementine successfully launched, spacecraft command language
(SCL) rule and script functions apparently operating OK. SCL, star
cameras, IRUs, and other hardware and software considered candidates
or baselined for Pluto.
o LeRC started work on 3-stage propulsion stack configuration
required for Shuttle-launched flight time <10 years and Shuttle/Proton
commonality.
o Mars Observer failure reports beginning to be taken under
consideration in Pluto mission development work.
o Information received at Albuquerque space nuclear symposium
on Russian nuclear payload safety practices.
o Various preproject personnel attended SwRI "mock PDR" for
their strawman integrated UV-VIS-IR instrument under NRA contract.
o Collaboration with JPL Microspacecraft effort will now permit
funding of industry star camera prototype to compare with Clementine
camera later in year.
o Galileo fault protection algorithms provided for part of SCL
evaluation for Pluto. Some Galileo and/or Voyager algorithms to be
written in SCL code.
o High-precision commercial "Inchworm" actuator tested to 190K
for possible application to Pluto scan or secondary mirror, to
possibly alleviate some attitude control requirements for high
resolution mapping data which are difficult to meet with present
attitude control subsystem. GSFC has qualified and flown Inchworms of
older design for Telsat at room temperature. Pluto would require
150-160K if used without active thermal control. Contract let to UCLA
for student work as part of this task.
o Product assurance work for spacecraft and instruments ranked
in priority for FY94 work on a few areas thought to be applicable to
other subsystems and instruments, selected based on limited resources.
o SCL software installed at Flight System Testbed.
o Pluto advocacy opinion piece in 1/10 Space News, mention in
12/21 New York Times profile of Dan Goldin, 1/10 AW&ST.
Erratum
o December report indicated that Martin Marietta delivered to
LeRC ROM cost estimate for 3-stage stack. This was in fact a JPL WAG.
Problems & Concerns
o Cost of carrying dual launch options.
-------------------------------------------------------------------------
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ Galileo S-Band | Failure is success if we
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | learn from it.
|_____|/ |_|/ |_____|/ | Malcom Forbes
|
| 886.7 | DSPSE camera ideas for PFF | MTWAIN::KLAES | Keep Looking Up | Tue Jun 07 1994 16:04 | 68 |
| Article: 2500
From: malin@esther.la.asu.edu (Mike Malin)
Newsgroups: sci.space.policy
Subject: Re: Whose camera...
Date: 3 Jun 94 18:20:30
Organization: TES Project, ASU, Tempe AZ
I'm afraid I missed Pat's posting regarding one of my messages from
last week--I was out-of-town and the ASU server seems to be purged
several times a day! Anyway, I gather from Bill Higgins' response
that Pat was suggesting using the DSPSE cameras on a Pluto mission,
and that stereoscopic observations could be achieved using two
cameras. Bill wasn't sure that bolting two cameras onto a small
spacecraft was the right way to acquire these data.
For Pluto Fast Flyby, several very advanced instruments are under
development by such diverse organizations as Ball Aerospace (teamed
with Southwest Research Institute to build a UV to near-IR high
spatial/high spectral resolution imaging spectrometer), JPL (building
a similar device), University of Colorado (building an advanced UV
instrument), and Goddard Space Flight Center (building an advanced NIR
instrument). These instruments, which will weigh in the ballpark of
the DSPSE payload (i.e., ~10 kg), will consume tiny amounts of power
(a few W), and will be moderately to very "smart," are at least as
advanced technically as anything "accessible" from BMDO, and will have
MUCH better science performance. Indeed, they all owe some heritage
to BMDO technology investments. The majority of their mass comes from
the optics needed to photograph Pluto and Charon from far enough to
cover most of the visible part of these bodies during the extremely
short (<<1 day) near-encounter (remember, whatever is sent to Pluto is
going to be moving really fast). Both line-scanners and framing
instruments are being developed.
Typically, stereo can be acquired either by a single, framing camera
taking successive images from different viewing angles, by a single
camera taking simultaneous observations looking in two or more
directions (and using spacecraft or body motion to move the target so
that the stereo overlap is established), or by two (or more) cameras
taking data in multiple directions (and again requiring motion to move
the target to establish the stereo overlap). The first is the most
often used: from the nadir pointing but large field of view Lunar
Orbiter framing cameras, through the Apollo Metric camera, though all
stereo observations from Mariner, Viking, and Voyager spacecraft.
Earth orbiting spacecraft typically use this technique, too, although
some have used line-scan or whisk-broom systems and either spacecraft
re-orientation or orbital sidelap coverage. Recent advances in stereo
imaging techniques use a single optical system to acquire multi-angle
views of the surface: the German High Resolution Stereo Camera on Mars
'9X uses three line-array detectors (foward, nadir, aft) to create
closed stereogrammetric solutions. No one, to my knowledge, has
proposed a binocular camera recently, although it should be remembered
that the very high resolution Apollo Panoramic Camera was a three
optical system (fore, nadir, aft) system of considerable
sophistication and quality.
The DSPSE cameras might not be too well for stereogrammetry, since
they have very small detectors. The best stereogrammetric solutions
come from the correlation of individual frames--mosaics are hard to
work with (the camera angles keep changing in known by odd ways across
a mosaic), and very small mismatches look like topography. Since I
don't have Pat's original message, I'm not sure what aspect of his
design drove him to a binocular system, but a good system, equal to if
not better than the DSPSE cameras, would not be difficult to make.
Mike Malin
Principal Investigator
Mars Global Surveyor Orbiter Camera
|
| 886.8 | Learning from Clementine | MTWAIN::KLAES | Keep Looking Up | Wed Jun 22 1994 21:45 | 72 |
| From: US4RMC::"baalke@kelvin.jpl.nasa.gov" "Ron Baalke" 22-JUN-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: Re: Space news from March 7 AW&ST
Henry Spencer writes:
>Editorial urging the administration to stifle its "not invented here"
>reaction to Clementine. Both Pentagon and NASA management have given
>it lukewarm support at best, and it deserves better. At the very least,
>Goldin should accept BMDO's offer to tour the Clementine operations
>center -- which is only a few minutes from his office -- to see how a
>bare-bones mission is done. Then JPL should be asked how it would
>staff a comparable mission.
Rob Staehle, the Pluto Fast Flyby Preproject Manager at JPL, wrote a
letter to Aviation Week in response to this editorial. A truncated
version of his letter appeared in the April 11 issue. With Rob's
permission, I'm posting the letter here in its entirety.
Ron Baalke
--------------------------------------------------------------------
David M. North, Managing Editor March 22, 1994
Aviation Week and Space Technology
1200 G Street
Suite 922
Washington, DC 20005
Re: Your Editorial, "NIH vs Faster, Better, Cheaper," of March 7
Dear Mr. North,
Clementine team members deserve our applause, and have set examples
worth emulating. Even before launch, Clementine work was beneficial
in Pluto mission developement. We requested, and Clementine managers
agreed, to a visit to their flight operations. JPL representatives
attended their PDR and CDR, bringing back ideas we have adopted. With
NASA's encouragement, we funded Lawrence Livermore National Laboratory
(LLNL) to support our mission development, and one of their staff
members attends our weekly meetings (by conference call) and most of
our reviews as a Pluto team member.
We borrowed for testing, and received extensive design and
qualification information on the Clementine inertial reference unit
and star camera. We are observing their experience with Spacecraft
Command Language, which could save operations and development costs.
Our planned Pluto operations team size is <30 people during cruise,
including project manager and secretary. Clementine is helping
validate our assertion two years ago that such a size would be
adequate to support our mission, as it was for JPL's Solar Memosphere
Explorer launched in 1981.
Differences in our missions account for some cost differences: our
two Pluto spacecraft must launch with a much higher energy, operate
for all of approximately ten years, transmit and navigate from 31 AU,
and acquire a very specific set of data during a brief encounter.
Pluto projected life cycle cost for our two spacecraft mission is less
than a third of Galileo, and comparable to Mariner 3/4, Mariner 10,
and Pioneer 10/11, while delivering dramatically greater science
capability with a smaller spacecraft to a more distant destination.
You are right to highlight the need for a "new, leaner approach to
missions" and the need to "put intramural rivalries aside." With
support from Dan Goldin and other far-sighted NASA managers, we have
been, and continue to improve, there necessary facets of "faster,
better, and cheaper."
Sincerely,
Robert L. Staehle, Manager
Pluto Fast Flyby Preproject
|
| 886.9 | Update - June 2 | MTWAIN::KLAES | Keep Looking Up | Thu Jun 23 1994 17:16 | 80 |
| From: US4RMC::"baalke@kelvin.jpl.nasa.gov" "Ron Baalke" 22-JUN-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: Pluto Fast Flyby Update - 06/02/94
Forwarded from Rob Staehle, Pluto Fast Flyby Preproject Manager
Pluto Mission Development--May Summary
Covering 1994 April 27 through June 2
o Pluto Options Review at HQ May 25: non-RTG and cost reduction
options. Based on extensive examination of non-RTG and cost reduction
options for spacecraft, launch system, EEMOS and operations. Cost
reductions ~$90M possible for RTG options, with longer flight times
and more robust early funding. Development cost increases of $70-100M,
plus reserves, plus ops cost increases for non-RTG implementations.
o Hughes Danbury Optical Systems (HDOS) contract executed and work
started for Planetary Micro Tracker (aka Star Camera) demonstration &
assessment.
o Video conference and information exchange with potential Russian
collaborators May 12: Drop Zond, Protons, Propulsion & Power. Pluto
s/c wet mass will increase substantially with Drop Zond: probe mass,
interface hardware, deflection maneuver propellant.
o EEMOS Design Workshop May 17 defined inputs, functions and outputs
for key elements to enable low cost MOS development and flight
operations. Onboard automated creation of informative engineering
data summaries is a key technical challenge to meet infrequent, low
rate downlink sessions.
o SCL-to-LabView software bridge written at CU, installed & verified
in Flight System Testbed. Key to simulated equipment running in Testbed
using software which will grow into ATLO and flight applications.
o Contract signed by JPL with U of Cincinnati for fault protection
simulation and evaluation. Part of EEMOS development.
o Contract add-on awarded to UCLA to modify design, procure,
assemble & test prototype "inchworm" microactuator to 150K.
o Pluto Integrated Camera System (PIDDP-funded) prototype hardware unveiled.
o Two new ~40AU objects suggest increasing potential for Kuiper Belt
object flyby post-Pluto. (1994 ES2 and 1994 EV3)
o Highest resolution to date Pluto images taken with Hubble (HST) faint
object camera.
o Outreach: Omni, Space-Time Continuum, video Out of the
Darkness--Mission to Pluto premiered at Toronto Int'l Space Dev.
Conf., JPL Student Shadow Day (5/ 19), JPL Industry Day(5/12), Frank
D. Parent Elementary School in Inglewood CA, Space News (5/2), NASA
Educational Horizons, Boy Scout and Cub Scout Testbed tours.
Former JPL co-op student with Pluto experience, Lilac Mueller/
MIT, hired full time. Former JPL/Pluto summer student Clark Snowdall
now CU grad student working at JPL full time for summer on EEMOS. 3
new undergrads @ CU working on Pluto EEMOS for academic credit.
o Rep. George Brown's proposed NASA authorization bill shows desired
FY96 Pluto new start.
o Papers at Low Cost Planetary Missions conference (mission, telecom,
integrated instrument), IEEE Conf. on Microwave Systems, Int'l Space &
Science Technology Conf (fs/c paper incl. Pluto, not paid by Pluto).
o No-cost extension granted on LLNL work for Pluto on star camera,
IMU and related efforts.
Rob Staehle
___ _____ ___
/_ /| /____/ \ /_ /| 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.
|
| 886.10 | PFF Preproject Summary | MTWAIN::KLAES | Keep Looking Up | Thu Jun 23 1994 17:16 | 288 |
| From: US4RMC::"baalke@kelvin.jpl.nasa.gov" "Ron Baalke" 22-JUN-1994
To: usenet-space-news@arc.nasa.gov
CC:
Subj: Pluto Fast Flyby Preproject Summary
Forwarded from Rob Staehle, Pluto Fast Flyby Preproject Manager
Pluto Fast Flyby Preproject
Challenge Summary
March 1994
The Mission
Current plans are to launch two spacecraft on separate vehicles
in 2000 or 2001 on direct trajectories to pass within about 15,000
kilometers of Pluto and Charon in 2007-2010. Development costs cannot
exceed $400 million in FY92 dollars. Total mission costs, including
spacecraft, instruments, launch vehicle, mission operations and data
analysis are not to exceed $750 million. The science payload was
chosen to explore specific aspects of the planet, much like the very
successful approach of Mariner and Pioneer missions in the past. The
core science objectives are to characterize Pluto and Charon geology
and morphology, map surface composition, and define the structure and
composition of Pluto's neutral atmosphere. This knowledge would
revolutionize our understanding of Pluto and Charon.
Challenges
Technical
o Pluto is the "Mount Everest" of planetary exploration. It is the
farthest, coldest, and hardest planet to get to. Earlier attempts to
design a Pluto mission concluded that the tough technical challenges
would be coupled with much higher costs. The exciting JPL proposal
currently funded by NASA's Solar System Exploration Division and
Office of Advanced Concepts and Technology is developing new
technologies and new management approaches to meet the technical and
political challenges of Pluto exploration.
Scientific
o Pluto and its moon Charon are unique: Pluto is the last
unexplored planet in our solar system. Pluto is neither like Earth and
the other terrestrial planets nor like Jupiter and the other gas
giants. Because Pluto is so different, it is an important piece of
the comparative planetology puzzle that offers breakthroughs in
understanding the origin and evolution of our solar system.
Political
o Budgets are tight, competition for NASA funding is high, arrival
at Pluto takes years.
Pluto Preproject Responds to the Challenges
o The Pluto Fast Flyby Preproject team is determined to create a
smaller, cheaper, faster, and better space science mission. Innovative
responses to the technical, scientific and political challenges of the
mission have been solicited from many sources:
o university students
o industry
o government agencies
o scientists
o educators
o engineers
o NASA
o Creative teaming is paying off
o Lower mass, lower power requirements, increased computer and
memory capabilities, and successful defense conversion have been achieved
through these collaborations.
o The Pluto team has earned high visibility through creative and
energetic outreach.
Students
o Over twenty colleges and universities have already participated, with
over 50 students significantly involved.
o Students in a variety of disciplines are getting hands-on experience in
developing new technology and other opportunities for involvement in the
mission and its results.
Industry
o Industry has responded to technical challenges with leading-edge
prototype hardware on rapid turnaround, always within allocated cost.
o Significant leverage has been obtained in synergy with recent and
ongoing DOD projects, enhancing defense conversion.
Other Government Agencies and Laboratories
o Department of Energy, Lewis Research Center, Marshall Space Flight
Center, and Lawrence Livermore National Laboratory all have important
roles, with assistance from their industry partners and contractors.
PFF is demonstrating "a new way of doing business"
o The Pluto mission is taking advantage of highly miniaturized
instrumentation: At 120-140 kg, the spacecraft weighs about a tenth of the
Galileo spacecraft; the capability of several Galileo instruments is packed
into 7 kg (18 lbs.)
o "Breadboards" (or prototypes) of critical instrument and subsystem elements
are being fabricated and tested much earlier than usual so that the
advantages and limitations of advanced materials and technologies can be
understood and that experience applied to flight equipment development.
o Students form a portion of the mission development team doing real and
original work in ways that help prepare them to be tomorrow's experienced
leaders.
o Cost estimates for the dual Pluto flyby indicate the mission can be built,
launched and flown to Pluto for about one quarter of the cost in 1994
dollars of Galileo.
o Industry has identified numerous ways in which their NASA funded Pluto
technology development work has advanced their competitiveness and may
improve society's quality of life.
Pluto Beckons
"It is the only true double planet known. It likely was created by a
collision of two planets and it is the only real analogy ever
discovered to the origin of the Earth-moon system. It is the only
planet with an atmosphere which, like a comet, builds up and then
collapses each orbit. It is the largest and most accessible relic of
the hundreds or thousands of small, icy planets believed to have
formed in the ancient outer solar system. It is sometimes called
Pluto, other times, the Pluto-Charon binary. It is the last world we
know of before the great gulf to the stars, and it has never been
explored by spacecraft..." Alan Stern, Southwest Research Institute,
San Antonio TX
Smaller, cheaper, faster, and better.
o Better alignment with the U.S. national needs for inspired education and
technical competitiveness: innovative, proactive management and outreach are
paying off in a widely distributed network of schools and companies.
"Rarely, does a new space program allow or even encourage completely new
ideas and design to be used in the project. ...The six students that
participated in the design, building, and testing of the adapter learned
more about engineering than (in) any single course they took. ...a real
chance to do something useful with their education"
Kurt Gramoll, Assistant Professor, Georgia Institute of Technology
"We believe that affording grants and cooperating with Historically Black
Colleges and Universities such as CSU (Central State University) will
greatly enhance the...creativity and competitiveness...of our undergraduate
minority students."
Arthur E. Thomas, President, CSU Wilberforce, OH
"Our manufacturing processes are advancing to cope with the demands of the
technology of our micro packaged computer...baselined for the Pluto flyby
mission. This advance in technology may well prompt our next major
commercial expansion."
Richard A. Holloway, Sr. Vice President, SCI Systems, Inc., Huntsville, AL
"We...are utilizing the Pluto miniaturized instrument technology toward
inexpensive remote sensing systems for potential commercial application."
David A. Roalstad, Director of Business Development, Ball Aerospace &
Communications Group, Boulder CO
"...involvement of our young engineers and scientists in exciting projects
such as the Pluto Fast Flyby mission...is exactly what attracted them to
space exploration in the first place, and unless we can continue to provide
such opportunities we will lose our brightest talent."
John M. Klineberg, Director of Goddard Space Flight Center, Greenbelt MD
"Hopes are high at the Colorado Space Grant Consortium...that students and
faculty may someday be involved in controlling the Pluto spacecraft..."
Jim Scott, Office of Public Relations, University of Colorado at Boulder,
Boulder, CO
o Better emphasis on lower cost, quicker development of cutting edge
technology: limits are inspiring innovative technology such as highly
miniaturized instrumentation.
"PFF, more so than the traditional Voyager-type missions, can be expected
to enhance our industrial competitiveness because it seeks to decrease
dramatically the time scale and the cost of developing and fielding systems
on the cutting edge of technology. ...The miniaturization of the
instruments and spacecraft systems that will be required for the Pluto
mission...will also be applicable to commercial systems from communication
and weather satellites to automobiles."
Martin Goland, President, Southwest Research Institute, San Antonio TX
"The Pluto Isogrid structures...provide light, strong, high reliability
aerospace structures (for) spacecraft, airplanes, automobiles and many
other products...improving the quality, reliability, safety and cost..."
Dr. Bartell Jensen, President, Utah State University, Logan UT
"...advanced digital receiver technology--like that being developed for
PFF--will be very much in demand...this technology will ensure U.S.
leadership in providing replacement(s) for ...U.S. communications,
meteorological, earth monitoring, military reconnaissance and treaty
verification satellites."
Frederick S. Brown, Vice President of Marketing, TRW Space & Electronics
Group, Redondo Beach CA
"Both Boeing Pluto activities have potential for commercialization. The
antenna concept ...maintains the high RF performance and ultra light weight
expected, but provides a remarkable cost reduction...the power conversion
concept...enabled us to propose a dual-use defense conversion program for
...commercial applications of low-cost clean electrical power production"
Dennis D. Smith and Ed Horne, Project Managers, Boeing Defense and Space
Group, Seattle WA
"ERIM is developing an efficient, light weight, and compact heat to
electricity AMTEC generator designed for the Pluto mission. ...AMTEC power
conversion...holds the promise of significantly reduced mass, higher
efficiency and lower cost than current RTG technology. ERIM believes that
in addition to its potential value for the Pluto mission, AMTEC holds
extraordinary potential for public benefit."
Thomas K. Hunt, Environmental Research Institute of Michigan (ERIM),
Ann Arbor, MI
o Better contracts: Agreements concerning size, mass, cost, and schedule
are clearly defined with absolute limits.
"We enthusiastically embrace and commit to, not only the contractual
objectives of our segment of the Pluto mission, but the project's broader
goals and philosophy..."
Richard A. Holloway, SCI Systems, Inc., Huntsville, AL
"We support the premise that contracts should be performed within the
contractual cost commitments. We are pleased that Boeing's two Pluto
mission projects...will be delivered...on schedule and within cost...You
can be assured that we will do everything possible to continue to perform
within cost in the future, thus assisting the government in meeting their
fiscal responsibilities as well as improving Boeing's competitive
position."
Dennis D. Smith and Ed Horne, Project Managers, Boeing Defense & Space
Group, Seattle, WA
"We are delivering the prototype service valves for the Pluto Fast Flyby ATI
Program...a full two weeks ahead of our schedule and over two months before
the need date shown in your specification. ...We are currently proposing a
(service valve) to a company in the midwest who is building natural gas
conversion kits for automobiles...its having been qualified for space
applications should convince them of its reliability."
Dean G. Giles, Project Manager, Futurecraft Corporation, City of Industry,
CA
"Ultra-Low Power CMOS technology...is extremely attractive not only for
Pluto but for the booming lap-top and mobile communication
industry...(further) research and development of low-power technology may
open up new industries and application areas such as in the electric
automobile industry as well as enable new low-power space missions."
Leon Alkalaj, JPL Robotics Section, Pasadena, CA
The Case for a Pluto Mission
"Each time we have looked at a planet with new eyes we see something
totally unanticipated. Can there be any doubt that this will be the
case with Pluto? Surely completing our solar system reconnaissance is
something we must do. Continuing to lead in planetary exploration is
part and parcel of being a vigorous, productive and stimulating society."
K. Michael Henshaw, Vice President, Martin Marietta Space Group, Bethesda, MD
___ _____ ___
/_ /| /____/ \ /_ /| 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.
|
| 886.11 | Latest Pluto info from The Planetary Report | MTWAIN::KLAES | No Guts, No Galaxy | Fri Aug 26 1994 20:53 | 43 |
| Article: 69174
From: billa@netcom.com (Bill Arnett)
Newsgroups: sci.astro
Subject: Pluto facts?
Date: Wed, 24 Aug 1994 13:56:03 -0700
Organization: Arnett, Arnett and Dunshee
The latest issue of "The Planetary Report" (published by The Planetary
Society) contains an article on page 8 by Alan Stern which very briefly
states some facts about Pluto:
- Pluto's orbit is chaotic over astronomical timescales
- Pluto is covered with exotic, super-volitile snows of nitrogen,
methane and carbon-dioxide
- Charon is encased in run-of-the-mill water ices
- various features have been seen on Pluto's surface: polar caps, hot
spots, other distinct markings
- Pluto's atmosphere is rapidly escaping
- Some of Pluto's atmosphere probably spills over into orbit about Charon
- Pluto is very likely a leftover mini-planet, the largest of the
1000-plus ice dwarf mini-planets, which seem now to make up the most
populous class of planetary bodies our solar system has produced.
Can anyone confirm or shed any further light on these statements?
--
Bill Arnett homepage: ftp://ftp.netcom.com/pub/billa/billa.html
email: billa@netcom.com
"Trying to define yourself is like trying to bite your own teeth."
- Alan Watts
"Talent is what you possess; genius is what possesses you."
- Malcolm Cowley
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