Conference 7.286::space

How come there's so much talk about non-power-glide landings ?

It's not that it doesn't make sense to me.  The shuttle does it.
I guess it's been proven to work.

But if it's so great, why aren't jet planes designed to land that
way ?

/Eric

    last may when i was in wash. i was at the air and space mueseum.
    there they had and exhibit of precursers to the shuttle, the first
    model there was a wind tunnel model of Saenger's space plane.
    the exhibit said that they had gotten as far as designing the
    propulsion system and had done some limited tests before the war
    ended, i was really amazed that the german's had such visionaries
    in the 1940's but then again it was probably meant to bomb 
    new york with guess what kind of bomb that was also being reseached.
    we were lucky if they had more time it could have been....
    SPRINGTIME FOR HITLER AND GER-MAN-EEEE.

    RE: .1
    
    The reason for non-power glide landings is weight saving from not
    having to carry the fuel.  The reason that jet planes do not employ
    the same method is because of safety.
                            
    Added weight, on a spacecraft, adds mucho bucks to the cost of the
    craft and the cost of flying it.  This is not as noticable on an
    aircraft, as it is designed to carry its own fuel during atmospheric
    flight (The shuttle is not - again, to make it so would add too
    much weight).  Also there is the safety factor.  The shuttle, and
    similar craft, MUST land on the first try -- no fuel for a second
    attempt.  You wouldn't get *ME* on a jet that only had one shot at
    a landing....         
    
    jim
    

    Jim is correct in .3. The shuttle was originally planned to jet
    engines for final approach and landing but that got canned, mostly
    for cost reasons.
    
    As it exists now, the shuttle's descent is carefully planned by
    a computer program called Energy Management System (runs on a VAX)
    that determines the glide path so that the shuttle will alnd at
    the right place with the right velocity. There is a very narrow
    margin between stall speed and max safe landing speed. Any unplanned
    flight deviation could result in significant landing damage to the
    orbiter.
    
    Yes it works. But it is not at all fault tolerant.
    
    gary

This idea of having just ONE CHANCE to do the powerless landing sounds quite
dangerous.

If powerless landings are rejected for aircraft due to safety, then in light
of the Challenger loss and increased safety awareness, will NASA still be
able to get away with powerless landings in the next shuttle flight ?

/Eric

    re .5
    
    In this case economy is better regarded then safety. Just think,
    how much it would cost the U.S. to give the shuttle just a second
    landing option.
    
    And in this point in time I agree with them, just as long as they
    crew it with people who know the risks and are paid to take them.

    Us sailplane pilots have been living with the idea of just one shot
    at landing for years,often in an unknown field with just a quick
    look from the air to size the correct approach path etc (then we're
    only doing 60 kts)
    
    			Dennis
    

    Yeah, but most of your garden variety sailplanes have at least
    an order of magnitude better glide ratio than the shuttle, and
    have no where NEAR the inertia built up.  The shuttle is, to be
    succinct, a flying brick.  (I remember hearing figures for the
    glide ratio of 1 foot of forward travel for 10 feet in drop in
    altitude, or somewhere in that area.)
    
    Oh, I also suspect your approach speed is a small fraction of
    the shuttle's.
    

       1 in 10 ain't that bad. The average club sailplane has about 1 in
    25,the hot ships around 1 in 40. As for inertia,who cares when you've
    got Edwards AFB to dissipate it in. What makes an unpowered approach
    easy or difficult is the amount of approach control that the vehicle
    has. I don't know how good the shuttle's approach control is but the flaps
    and airbrakes certainly LOOK big enough. The point of 304.7 is not to
    say that unpowered approaches are easy but to express the opinion
    that with craft such as the Shuttle, Hotol etc the unpowered approach
    is one of the lesser hazards.

No, the glide ratio of the shuttle, using your terminology is 10
in 1; the previous reply said that the shuttle travels 1 foot
forward for every 10 feet of drop.   Or, are you saying that a
glider drops 25 feet for each foot forward?

By the way -- and I know this is a tempting rat-hole; but I saw
the IMAX (kind of a very large screen cinemascope) show up in
Denver a few weeks ago where  they showed a sailplane film.  They
put the camera in the cockpit and gave you a real pilot's eye
view.  Never knew the sailplanes were capable of such high
performance!   Must be a blast...

       10 in 1 ohhhmygod,a rubber stamp does better than that,can anyone
    confirm this? It certainly seems to flair O.K.
    	To follow down the rathole,modern sailplanes do have a very
    good performance. I've been to 20,000ft and been round a 300 kilometer
    triangle (not at the same time) and there are a lot better pilots
    than me around.
    
    			Dennis
    

    re: .many...
    
    the 10 in 1 glide configuration is correct, though stated out of
    context.
    
    The shuttle enters what is known as 'glide configuration' at a very
    high altitude (shortly after reentry).  'Glide configuration' is
    that time when the shuttles control surfaces are activated and
    effective.  This mode is entered at about Mach 11 to Mach 12.  This
    is when the 10 in 1 glide ratio is seen.  As the shuttle enters
    denser air, the glide ratio levels out to something more in line
    with that of a gliding craft.
    
    Rest assured that the shuttle does NOT make a landing approach with
    a 10 to 1 glide (drop?) ratio!!!
    
    jim
    

    This will sound outrageous, but the figure 4-1 sticks out in my
    mind. I will have to look this up. Yes, talk about lead balloons!
    

       4 in 1 still sounds a bit drastic. Watching on the box it looks
    about 1 in 5 which is about the same as the average Spam Can(Piper
    Cherokee etc). This again is not to bad with proper approach control,
    Student pilots studying for a British PPL (Private Pilots Licence)
    are expected to demonstrate a successful simulated engine failure
    as part of the general handling test,the power failure being applied
    unexpectedly by the examiner.
    	The actual landings carried out by the various shuttle pilots
    are certainly impressive whatever the performance of the vehicle
    (I didn't know I had landed until I heard the applause).
    
    			Dennis

    On final approach to the Cape, the glide ratio is about 4.7:1, i.e.
    1 foot down for every 4.7 feet forward. Airspeed is about 210 mph.
    This may be with a payload.
    
    As the shuttle enters appraoch and landing phase, i.e. lined up
    with the runway and at about 20,000 feet it enters a steep descent
    phase with a glide slope of 22 degrees. During this phase, its vertical
    speed is over 140 mph. It would overtake a skydiver in free fall!
    (usual terminal velocity of a skydiver is about 120 mph)

    gary

    I have seen the shuttle land at Edwards AFB (Columbia, Spacelab
    I), and I can confirm from visual observation that it is indeed
    heading for the ground hell-bent-for-leather.  I have a photo which
    is quite incredible.  I remember keeping the camera level, but of
    course there are no landmarks in the picture, so I could have been
    faking it.
    
    A little babbling:  If you remember, Spacelab I was the flight where
    one of the GPCs (computers) died just before they were planning
    to reenter, so they were waved off.  It took more than one or 2
    orbits to get it fixed, so EAFB had rotated out from under the orbit
    too far.  However, Spacelab had a larger inclination than EAFB's
    lattitude, which meant that after a few hours, EAFB came into range
    of the *decending* segment of the orbit.  This is the way they landed.
    The significance of this is that the shuttle approached EAFB from
    the NORTHwest rather than the SOUTHwest and ended up doing nearly
    a full circle around  the HAC (heading alignment circle) rather
    than just a fraction.  This meant that they went *right* *over*
    the parking lot where I was.  What a view!
    
    Burns (viewer of STS-1 liftoff and SL-1 landing and hoping for more)
    

        1:10 sounds quite wrong to me, Jim. That would be almost a
        vertical dive. I don't think they ever come down THAT steep. My
        recollection is that the shuttle has a 2:1 glide ratio, and on
        final aproach it pulls back to the 5:1 number that Gary refered
        to. 2:1 would be close to Gary's 22 degree figure. Some of this
        improvement is from ground effect; you can see how the shuttle
        just hangs above the runway and slowly drops in its last few
        seconds before touchdown. 

    RE: .17
    1:10 is correct.  But understand that this is at the begining of
    the glide, when the craft is in *very* sparse air.  In fact, from
    what I have heard, the ratio does a complete flip sometimes durring
    the landing (eg: at times the glide is 10:1)  Probably the greatest
    glide delta of any craft known.
    
    jim
    

VNS MAIN NEWS:                            [Richard De Morgan, Chief Editor, VNS]
==============                            [Basingstoke, England                ]

    UK News
    -------

    ZIRCON spy satellite project abandoned over fears that technology would
    be obsolete when it was completed. Meanwhile, British space projects have
    been thrown into disarray by the resignation of the Director-General of
    the BNSC: ESA warn that industrial contracts are dependent on upfront
    money from countries; the BAe/Rolls Royce HOTOL project, which could have
    cut launch costs by 80%, will probably be transferred to the US.

  <><><><><><><>   VNS Edition : 1375    Thursday  6-Aug-1987   <><><><><><><>

From: bob@its63b.ed.ac.uk (ERCF08 Bob Gray)
Newsgroups: sci.space
Subject: There's hope yet
Date: 7 Mar 88 17:42:54 GMT
Organization: I.T. School, Univ. of Edinburgh, U.K.
 
    Just when you thought the UK space effort was dead and buried...
 
    One of the UK's computer trade newspapers "Computer weekly"
carried a front page article on Feb 25th edition entitled: 

	"Space project offers boost to software work".
 
    I quote some excerpts from it.
 
	"British Aerospace, the principal architect of the HoToL
	programme - the UK's answer to the space shuttle - has asked
	eight software houses to help it develop the software
	technologies required to make the programme a reality."
 
	"Software productivity and reliability are the key issues if
	British Aerospace is to build the command and control system
	for HoToL in an acceptable development time. Using existing
	tools would require 3,000 worker years of effort - BA wants
	to reduce that to 300."
 
	"The HoToL programme to produce a re-useable reansit van 
	for the 21st century requires twice as much code as the
	current all-electronic planes."
 
	"It is also planned to cut down the size of team required to
	fly the HoToL van. ... it takes 5,000 people to operate
	the US shuttle."
 
	"Over the next few months the club of software eight software
	houses will iron out a programme of research. ... BA has
	already set up another such club, to work on another
	technical issue for HoToL - advanced material."
 
	"HoToL needs some 5 billion pounds investment over
	the next 10 years."
 
    It is worth noting that one of the software houses, Logica, was
the main candidate do be awarded the contract by ESA for the software
systems on Columbus. (The ESA module of the US space station). Logica
had already spent large sums of money on preliminary research, before
the UK Government finally pulled out of the project a couple of weeks
ago. This was the only one of the three ESA special projects the UK
didn't give a definite no to at the ESA meeting last November. (Hardly
encouraging private enterprise). 
 
    Other developments in the last couple of days worth noting.
 
1. BA has put in a bid to buy the UK Government owned car makers,
   previously known as British Layland (amongst others).
 
2. BL has close ties with Honda.
 
3. Honda has no aerospace expertise, unlike other Japanese car
   makers, and has expresed an interest in entering the field.
 
    I leave it to you to work out your own conclusions.

	Bob

    	Today's VOGON News says that the British government has declined
    to fund the HOTOL spaceplane.
    
    	Nothing like progressive thinking, is there?
    
    	:^(
    

    Re: -1
    
    If you like that idea, you'll love President Dukakis.  The recently
    approved Democratic party platform calls for cancellation of the
    Aerospace Plane, ALS, and work on advanced shuttles.

    NO DUKES if you want a real space station
           
    It looks like  he thinks we can get by without a permanently  manned
    space station
         
    I think the answear is we need both, I  hope he does not put us backwards
    with the debates of man vs unmanned again
                       
                                                          
    

    This is great.  I think we've found the one Democratic candidate
    who's anti-space program.  We already know the Republicans want
    nothing to do with a space program, unless directly related to SDI.
    
    What now?  A B-1C with a few thousand JATO bottles strapped to its
    belly?
    
    This is making me sick...

    It might be a good thing if the U.S. space program got scrapped.  If
    space is really all we claim it is, then private industry would step
    in, right?  We're kidding ourselves if we think that any sort of a
    majority of the people in Washington are thinking of the future of
    mankind.
    
John

    Well, ideally NASA is getting out of the commercial launch business,
    DOT and others have been told to stop restricting private launch
    services, and private enterprise will take care of the rest.
    
    If you believe that the beaurocracy is really going to loosen the
    reins on private launch companies, I've got a bridge you might be
    interested in....  Of course if you are one of the biggies in teh
    aerospace community already, it might be a little different.
    
    Willie

VNS MAIN NEWS:                            [Richard De Morgan, Chief Editor, VNS]
==============                            [Basingstoke, England                ]

    Science, Technology, Medicine, and Nature
    -----------------------------------------

    Some of the details of HOTOL, the revolutionary proposed space vehicle 
    which the govt has declined to fund, have now become available and are 
    reported in The Times.  The engine, the Rolls Royce RB545, is initially
    powered by liquid hydrogen and air for the first 10 mins after the
    takeoff at 250 mph from a rocket-powered sled.  At Mach 5 it swiches to 
    LOX as the oxygen supply.

  <><><><><><><>   VNS Edition : 1620   Wednesday 27-Jul-1988   <><><><><><><>

Newsgroups: sci.space
Path: decwrl!labrea!rutgers!rochester!dietz
Subject: Info on HOTOL
Posted: 27 Sep 88 20:01:10 GMT
Organization: U of Rochester, CS Dept, Rochester, NY
 
    I've just read an article about HOTOL by B. R. A. Burns, the
project manager at British Aerospace.  The article appeared in
Interdisciplinary Science Reviews, 13(2), 1988, pages 171-179. The
article was apparently written before the British government decided
to halt funding.  
 
    The article explains a bit about the engines, although they are
still classified.  The engines cool and compress incoming air, but
apparently don't liquify it.  The compressed air is used in dual-mode
rockets (the other oxidizer being LOX, of course). 
 
    Also, the article explains those funny protuberances on the back
of the air intake thar were apparent in the picture of the HOTOL model
that appeared in AW&ST some time back.  On the trajectory the HOTOL
flies, it needs a larger air intake the faster it goes (this is unlike
a conventional supersonic plane, which needs a larger intake at low
speed).  The protuberances are vents to release excess air at lower
speed.  This also explains why HOTOL does not continue to breath air
above Mach 5:  The air intake would have to be too large. 
 
    Paul F. Dietz
    dietz@cs.rochester.edu

    The latest thing to enter the HOTOL arguement -
    
    (Flame on)
    
    The Engine design is classified, and the govornment has refused
    to put up any more funds for the next stage of development (ONLY
    5 million pounds)

    So:
    We aren't going to do anything to it (The UK) as RR and BA aren't
    prepared to invest that sort of money without some sort of external
    backing, and we can't get anyone else to do the work (IE sell the
    design to USA or someone else) as the engines have "distinct military
    possibilities"
    
    (5 million pounds - is that 1/2 a TRIDENT, or 1/4) - if we built the
    engine ourselves, we wouldn't need to buy Launch systems from the
    states, (which hopefully we'd never use) AND we'd have a commercially
    viable ??service only?? product.
    
    Yours,
    
    Angry of Basingstoke
    (Flame off)

Re: .29

I don't know where this information came from, but unless it's very recent
it's wrong.

Last I heard a few weeks ago was that British Aeerospace and Rolls-Royce
had decided that they could spend some more money on it and there was also
some other non-governmental source of funding.


I must say that the British government's attitude to scientific research is
extremely negative.  In the nuclear area not only have they announced that
fast reactor research will be terminated (the British program is perhaps
the world's most successful), but the latest leaks indicate that fusion
research will be completely cancelled as soon as the JET program ends in 1992.

jb

    Does anyone have any further info on HoToL?
    
    Cheers.
    
    Nick Pee

    Re: .31
    	Last I heard the project is still underway. There are also studies
    being performed to see if an air launched version HOTOL would make a
    better design (the present baseline design calls for a sled launching
    mode). The Soviets have stated (and possibly formally offered by now)
    that the new An-225 aircraft would be a suitable platform for air
    launch.
    	The air launch mode is being examined because one of the major
    problems with the current baseline design is that it can not make an
    emergency landing fully fueled after a sled launch because its weight 
    would exceed the limits of the landing gear (stronger landing gear would 
    weight too much for HOTOL to carry any useful payload). In an air launch
    there would be the option to return the HOTOL if some problem arises
    before it is released. In addition, an air launch could potentially
    increase the payload capability (or conversely be used to lighten the
    craft, etc.)
    
    					Drew
    

    Thanks for the info.  Have any kind patriotic souls decided to offer
    any funding?
    
    Nick Pee

Yuck!  I can just see it now:  Fuel tanks with ejection mechanisms.

(Just one of those little details (emergency landings, fully loaded) that never
even occur to "civilians" like me.)

From: ESC1325@ESOC.BITNET
Newsgroups: sci.space
Subject: Hermes crew escape system
Date: 26 Mar 90 15:06:18 GMT
Organization: The Internet
 
 From: Lutz Massonne             +49 6151 886 701     ESC1325  at ESOC
 To:   SPACE@ANGBAND.S1.GOV
 Subject: Shuttle escape
 
 For the European Hermes spaceplane it was decided (according to newspaper
 reports) to buy the Soviet ejection seats developed for the shuttle Buran.
 The ejection seats will enable the crew to eject during the first 90 seconds
 of the flight, placing them 500 m away from Hermes in 2 seconds.
 Ejection will be possible up to 30 km altitude and a velocity of
 3000 km/h.                                                          
 
 Regards, Lutz Massonne
 
  +===================================+===============================+
  | Lutz Massonne                     |   ESC1325@ESOC.BITNET         |
  |                                   |                               |
  |                                   |This mail expresses my personal|
  | Robert-Bosch Str. 5               |opinions only and is in no way |
  | D-6100 Darmstadt, FRG             |official or reliable.          |
  +===================================+===============================+

This isn't the normal egress method for good reason. The general feeling is that 
the seat occupant needs to get away as quickly as possible or be killed. Pilots
are generally knocked out by the forces and banged around. Bones get broken but
in general it improves the chances of survival. The other choice is to stay with 
the craft to whatever end. Challenger pointed out what that means. The fortunate 
part is that the seat occupant has no active role after "punching out".

    Re:.36
    	500 meters in 2 seconds would yeild an average acceleration of 
    250 m/s/s or about 25 Gs. It certainly would not be a pleasant
    experience but it is better than the alternative!
    
    				Drew
    

    It doesn't have to be 25 Gs.  If the crew is ejected in the opposite
    direction of the spaceplane, or with some vector in the opposite
    direction, then the vehicle's forward motion would contribute some,
    if not much, of the 500 meter distance in 2 seconds.

    jim

    re: .39
    
    I think that's true only if the vehicle is still accelerating, a
    dubious assumption.  If it isn't accelerating then a crew member
    ejected at 0G (to choose an easily-visualized case) will continue
    to accompany the vehicle.
    
    I am reminded of stories of a high-risk "bail out" feature in a world
    war II plane.  I think the position involved was the tail gunner's,
    and I don't remember the name of the plane at all.  According to the
    story, the only way to eject from that position was downward through
    the skin (some problem with the tail prevented ejecting upward).  Under
    operational conditions, according to the story, no crew member made
    a successful ejection.  ("Successful" means he lived to tell about it.)
    Nevertheless, there were several attempts.  I wonder of this ejection
    system might turn out to be in the same category.
        John Sauter

I heard a story from an eyewitness about a downward-ejecting seat.  It could
have been a B52, but I'm not too clear on that.  It seems that some work was
being done in the circuitry and somehow the safety "on the ground" interlock
was disabled.  Then someone managed to eject while the plane was on the
runway.  Not a pretty sight.  It left a big hole.

Burns

    Early models of the Lockheed F-104 "Lieutenant Eater" had a
    downward-firing ejection seat, designed to prevent a pilot from
    striking the empennage during as high-speed ejection.  Unfortunately,
    as most ejections occur at low altitude (i.e. takeoff and landing),
    this arrangement was less than optimal.

    yes in Rotc they show us a film of a f-104 with a flameout
    on take off and he tried to eject, they now tell you if you
    get a flame out on take off in a F-104 do a roll over...sure...
    
    But on a shuttle mounted to a booster it has to be a upward-firing
    ejection seat, but I guess if you don't use a booster you can go
    many different ways.  I wonder if other enginering considerations
    were used, ie the placement of the heat shields, the effectiveness
    of ejecting withing the first few seconds etc.  Is there an Engineering
    benifit or it is just what you can buy.... or worse yet a political
    problem...
    
    I think then in the French Air Show the Soviets showed there plan
    carring the Hotel....
    
    john
    

    Forgot the reason the ROTC gave on the F-104 downward-friing ejcection
    seat was the fact of the high tail with it razor sharp edges.  They
    had problems clearing it at supersonic bailout.
    
    jb
    

    I always thought that 25G's would be beyond the limit of what a person
    can withstand.  Isn't it fatal?
    
    jim
    

Re: .43, etc., F104 bailout
From F-104 ex-jocky in the flying notes file...
The seat  went  down  because  the  designers  didn't feel that they had the
technology  to  make  *any* ejection survivable at low altitude at the time,
therefore it was to be used only at high altitude and downward would be just
fine.  Later,  technology  improved  to make low-altitude ejection safe, and
then the downward ejection became a problem.

    At 25 g's, a 150 pound man would experience something like a "weight"
    in excess of 3000 pounds. I'm not convinced this is livable.
    
    steve p

  Modern fighter pilots can sustain 9 G's with pressure suit and special
training for short periods (10 seconds or so).  Instantaneous G's well above
this have been experienced in tests for much shorter periods (a second).

John

What is Col. Stapp's G record?  I think it is in in the 20's, and it still holds,
so far as I know.  (No one else crazy enough to try to break it, or else no one
could take the political heat of endangering even a volunteer like the did with
Stapp in the 50s.)

Burns

The idea is to improve the survival chances. Get away so that the medics have a 
broken but repairable body to work on ;^)

In many cases a 10% survival rate is better than staying with the plane.A

RE:    <<< Note 304.50 by DECWIN::FISHER "Prune Juice:  A Warrior's Drink!" >>>

Stapp experienced 86 G's for a very brief period (something like .004 second).
						-- Tom

    Ho-kay, whatever happened to Colonel Stapp?  Is he still with us?  And
    if not, wny not?
    
    Mac.

If he's dead, it was not because of the acceleration experiement.

Burns

I recall that he was kept in a hospital for three days after the sled run for
observation, and that no lasting harmful effect was found that was attributed
to the experience.
						-- Tom

From: henry@zoo.toronto.edu (Henry Spencer)
Newsgroups: sci.space,sci.space.shuttle
Subject: Space news from September 10 AW&ST etc.
Date: 19 Nov 90 03:59:15 GMT
Organization: U of Toronto Zoology
 
    Heavyweight aircraft of the month:  British Aerospace and the
Soviet Ministry of Aviation Industry propose reviving Hotol [!], using
an Antonov Mriya to carry a rocket-powered version of Hotol aloft,
avoiding the need for an advanced airbreathing engine.  Estimated
payload to a low near-equatorial orbit is 7 tons, and costs are
estimated to be about $2000/kg, roughly a third of that for Ariane 5. 
Re-engining Mriya with Rolls-Royce engines is being kept as a reserve
possibility against the chance that Hotol will gain weight in
development.  The Soviets are investigating the carry and separation
aspects, and also the possibility of using Soviet oxyhydrogen engines
in Hotol.  BA is looking into the modified Hotol, plus support and
economics.  Both sides consider it promising, and estimate an
operational date circa 2000 if all goes well and funding (perhaps
$4.6G) can be found. 
-- 
"I don't *want* to be normal!"         | Henry Spencer at U of Toronto Zoology
"Not to worry."                        |  henry@zoo.toronto.edu   utzoo!henry

    Re. .56:
    
    I thought the advanced air-breathing engine had already been developed
    by Rolls-Royce? Why would they want to avoid needing something which
    was already developed?
    
    If we didn't have all those bean counters here in the UK, this thing
    would be nearly operational by now.
    
    
    Dave Hazel

Article: 1092
From: Ian.Taylor@rcvie.co.at (Ian Taylor)
Newsgroups: sci.space.news
Subject: Project Interim Hotol
Date: 27 May 92 18:39:43 GMT
Sender: usenet@news.arc.nasa.gov
Organization: Alcatel Austria - Elin Research Center, Vienna
 
The recently published Space Technology International 1992 by Cornhill
Publications contains an intersting update on the `Interim Hotol'
project written by Dr Robert Parkinson of British Aerospace (BA). 
 
Abstract:
 
Interim Hotol is joint BA/Soviet Ministry of Aviation {sic} study into
the use of an Antonov An-225 Myria heavy lift aircraft to carry the
Hotol reusable orbiter. 
 
The Central Aero and Hydrodynamics Institute (TsAGI) near Moscow took
technical responsibility and used the Molnyia Design Bureau (of Buran
fame) for system studies. The Chemical Automatics Design Bureau
(responsible for the RD-0120 Energia second stage engine) assisted
with the Hotol main engine design. 
 
Orbiter concept: 

	4 hydrogen-oxygen engines
	`small' delta wing 
	integral payload bay
	total all up mass 250 tonnes
 
Operations:

	300km easterly orbit with 5-8 tonnes payload
	launch costs US$12m {$1090 per lb}
	24 flights per year
	No operational date or development costs given :-( 
 
Launch profile:

	takes off piggy back on modified An-225 (two extra Lotarev D-18 engines)
	requiring a 3000m runway for equatorial operations
	40 minutes to climb to 9,400m
	at release-60 sec An-225 enters shallow dive to mach 0.8
	at release-15 sec An-225 rotates to slightly nose-up while descending
	orbiter main engine ignition sequence started
	at release main engines started
	release+4 sec lower engine pair started
	orbiter should move vertically upwards wrt An-225 {exciting stuff eh?}
 
ESTEC completed extended technical review in September 1991, next step
is to establish joint European technology program to validate study.
{pending death of Hermes?}. 
 
Activities continue at BA and TsAGI.
 
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