Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_2/V16NO219.TXT

Text File | 1993-07-13 | 30KB | 720 lines

Date: Wed, 24 Feb 93 05:00:07
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #219
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed, 24 Feb 93       Volume 16 : Issue 219

Today's Topics:
                       Aurora (rumors) (3 msgs)
                      Aurora and SR-71 phaseout
                        Canadian SSF effort ??
                           Flight sim books
              Fred is Dead! Long Live the Space Station!
             Getting people into Space Program! (2 msgs)
                  Nobody cares about Fred? (3 msgs)
      Regularly updated Weather images ... help with HDF format?
                          Shuttle refueling
            Shuttle refueling was(Re: Sabatier Reactors.)
                            SSTO/DC-X GIFs
                       Stars in space pictures?
   Wouldn't an earth to moon shuttle be better than fred? (2 msgs)

    Welcome to the Space Digest!!  Please send your messages to
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----------------------------------------------------------------------

Date: Mon, 22 Feb 1993 18:24:37 -0500
From: Lawrence Curcio <[e-mail]>
Subject: Aurora (rumors)
Newsgroups: sci.space

Uh, it may be fast and all but, uh, what good is an audible spy plane?

There. I asked it and I'm glad!

-Larry C.

------------------------------

Date: 22 Feb 93 21:44:18 GMT
From: Tracy Ratcliff <[e-mail]>
Subject: Aurora (rumors)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Alan Dunning) writes:
>
>The latest issue of _Popular Science_ (March or April, I think) has a
>cover story about "Aurora."  . . .

The part of the article that intrigued me is the sketch of the 'Mother Ship'.
It's described as a cross between an SR-71 and an XB-70, with a large flat
dorsal area, apparently for carrying an air-launched vehicle of some kind.
What could you do with a 'mother ship' vehicle capable of Mach 3?

I get to read _Popular Science_ every month, but I don't keep up with the more
technical magazines on aerospace, so if this has been discussed to death
there or in some other net.newsgroup, my apologies.


------------------------------

Date: Tue, 23 Feb 93 17:37:53 MET
From: [e-mail]
Subject: Aurora (rumors)

From "New Scientist", 21 March 1992

"Blackbird comes back in spaceplane test", Dan Charles, Washington DC

  The retired SR-71 Blackbird spy plane has become a flying test-bed for
the National Aerospace Plane being developed by NASA. The NASP is
designed to take off from runways on Earth and fly into orbit at speeds
of up to Mach 15.
  NASA engineers will soon begin experiments to see if igniting hydrogen
in the air behind the NASP will help to push it through the sound
barrier. The approach, called "external burning", is supposed to reduce
aerodynamic drag.
  The experiments will be carried out on SR-71 aircraft that NASA
received from the US Air Force last year. The aircraft can cruise at
Mach 3, or three times the speed of sound, and were once sent on spy
flights along the borders of the Soviet Union and over Cuba.
  The SR-71 will carry a half-scale model of the back end of the
prototype NASP mounted above its fuselage on a two-meter-long pylone.
Hydrogen released from 19 small nozzles on the model will be ignited
in flight. Sensors will record the pressure and temperature of the
air behind the model.
  External burning is one approach to solving one of the most important
aerodynamic problems for the NASP: the "base drag" that results from
the large surface area of its back end. This large surface comes into
its own at speeds above Mach 3, when large amounts of exhaust gas from
the plane's engines push against the entire surface, producing thrust.
  At lower speeds, however, there is not enough fuel burnt in the
engines to pressurise the whole area. Pocket of low pressure form at
the back of the aircraft, producing drag. John Hicks, a manager for the
NASP project, says that around the speed of sound the drag is so severe
that it would prevent the NASP from ever breaking the sound barrier.
  Burning hydrogen in the air behind the aircraft as it accelerates
from Mach 0.8 to Mach 3 will produce extra pressure in this region and
overcome the drag, says Hicks. Experiments in wind  tunnels have
already demonstrated that external burning can be effective.
  Don Lux, of NASA, who is helping to prepare the test flights, says
that the experiments with the SR-71 are designated to see if the
hydrogen can be ignited reliably. "At a thousand miles per hour, you
can imagine, it's not like flicking on a lighter," he says.
  Heating produced by friction with the air has complicated
preparation for the experiment, says Lux. At Mach 3, the leading
edge of the model during the NASA experiments will be heated to 345
degrees C. This has meant using durable and expensive materials,
including special wiring with insulation that will not melt.

(end of article)
--------------------------------------------------------------------
Now a couple of questions about Aurora:
1. If the reported sightings are correct, Aurora is "large and
primarily delta shaped". It has probably big engines since it
goes at Mach 6-8 (if it exists). Could Aurora have the same "base
drag" problem as the NASP ?
2. If yes, how did Skunk Works solve this problem ? Is it conceivable
that they did not give the solution to these poor people who are
working hard at Ames-Dryden ?
3. If there were no Aurora, could the SR-71 produce the "airquakes"
reported in the Los Angeles area ?

J. Pharabod

------------------------------

Date: 22 Feb 93 23:12:00 GMT
From: Donald A Martin <[e-mail]>
Subject: Aurora and SR-71 phaseout
Newsgroups: sci.space

-------------------------------------------------------------------------------
    Regarding the SR-71 phaseout:
        Gee, doesn't anyone believe satellites can do the same job
        as the SR-71, if not better?

I Do ................................................................ Not!

------------------------------

Date: 22 Feb 1993 21:12:34 GMT
From: Doug Mohney <[e-mail]>
Subject: Canadian SSF effort ??
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Kieran A. Carroll) writes:

>impure. The present situation has a similar feel, as if the
>main thing that Clinton has against SSF is that Reagan and
>Bush supported it.

It's long term politics.  Between SSF (redesign mark 4?) and the SooperDooper
collider, there's a lot of money going to Texas.

One cannot easily kill a pig who hath sipped from the magik trough!


                    I have talked to Ehud, and lived.
  -- >                  [e-mail]                        < --

------------------------------

Date: Mon, 22 Feb 1993 14:57:59 GMT
From: Michael Lewis <[e-mail]>
Subject: Flight sim books
Newsgroups: comp.ai,comp.dsp,comp.graphics,comp.lang.idl,comp.lang.idl-pvwave,sci.space,sci.image.processing,comp.soft-sys.matlab

Can anyone point out some good (any) books on flight simulation. I'm
in the process of writing a flight sim but need to know about the
design aspects of creating a flight simulator.

--
Michael Lewis
Unix Systems
Lehman Brothers Inc.
388 Greenwich St.   11th Floor, NY NY 10013
Email:   [e-mail]
voice:   212-464-3389
pager:   212-812-9505 pin#70737

------------------------------

Date: Tue, 23 Feb 1993 00:03:41 GMT
From: Josh Hopkins <[e-mail]>
Subject: Fred is Dead! Long Live the Space Station!
Newsgroups: sci.space

[e-mail] (Thomas Clarke) writes:

Both sets  of >'s

>> P.S.  I must admit, one thing I have against Fred is the way it looks.
>> It just doesn't look like a space station.  (Nor does the shuttle
>> look like a rocket ship).

>I strongly believe that in good engineering, form follows function.
>If a device does not look right, then either
>a.  it has the wrong function, it does not work as desired, or
>b.  it is poorly engineered

I agree to some extent, but not completly.  I'm reminded of a great Volkswagen
add in the issue of "Life" that covered Apollo 11.  It had a simple picture of
the LEM and the caption "It's ugly, but it gets you there."

Remeber that even if Von Braun, Willey Ley and others may have been visionaries,
but they didn't imagine composites or microcomputers and they didn't know
much about hypersonic flight, nuclear propulsion or a thousand other things.
Their pictures may be great art, but they probably aren't great engineering.
--
Josh Hopkins                                          [e-mail]

    You only live once.  But if you live it right, once is enough.
            In memoria, WDH

------------------------------

Date: Mon, 22 Feb 1993 22:25:29 GMT
From: Dave Michelson <[e-mail]>
Subject: Getting people into Space Program!
Newsgroups: sci.space

In article <[e-mail]>, prb@access (Pat) writes:
>
>Seriously.  My point was that the X-15 was qualifying astronauts
>at a rate that I think the SHuttle only passed recently.


I just checked the list of all 199 missions flown by the X-15 between
1959 and 1968.

X-15 pilots in order of first flight and (1) affiliation, (2) number of flights,
and (3) number of flights over 250,000 feet.

  A. Scott Crossfield  NAA  14   0
  Joseph A. Walker     NASA 25   3
  Robert M. White      USAF 16   1
  Forrest S. Petersen  USN  16   0
  John B. McKay        NASA 29   3
  Robert A. Rushworth  USAF 34   1
  Neil A. Armstrong    NASA  7   0
  Joe H. Engle         USAF 16   3
  Milton O. Thompson   NASA 14   0
  William J. Knight    USAF 16   2
  William H. Dana      NASA 16   5
  Michael J. Adams     USAF  7   1
  ----------------------------------
                           199  19
  ----------------------------------

Of 12 X-15 pilots, it appears that 8 earned astronaut wings.


---
Dave Michelson                             University of British Columbia
[e-mail]                                  Antenna Laboratory

------------------------------

Date: Mon, 22 Feb 1993 21:41:45 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Getting people into Space Program!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Pat) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>In article <[e-mail]> [e-mail] (Pat) writes:
>>>
>>>No, the 15 was orbital, but it could and did cross the "Space"
>           s/was/wasn't/  (typo folks)
>>>boundary on numerous missions.    It had an operational
>>>level good enough that it could almost fly military Missions.
>>>If you had a missile or platform you wanted to carry up that
>>>high.
>>
>>Whoa. The X-15 didn't have provision for internal or external
>>missile stores. No hardpoints, no bay. The X-15 could reach
>>350,000 feet, but it couldn't *do* anything up there. It was
>>strictly a hypersonic research vehicle.
>>
>Most Military aircraft dont have weapons until one is designed
>for it.   Hardpoints are only part of the issue.  control systems
>need to be built and weapons dynamics have to be tested.
>Somehow I figured, that if someone wanted badly enough to
>put a sensor or weapon onto the X-15,  the engineering would
>not be implausible.   Somehow, I doubt designing a hard point
>would have been beyond the design team.

Most modern military combat aircraft are best appreciated as an
envelope designed around a particular set of weapons systems.
The skinless F-86 at the Air Force Museum highlights this very
well. The X-15 was designed without provision for internal stores,
and without provision for external structural hardpoints. Adding
either of these is not simply a matter of tacking them on. Mass
distribution and balance of the vehicle would be highly impacted
by carrying stores. Also, hypersonic weapons release from a hardpoint
has never been demonstrated. Some designers seem to think it's a very
difficult problem. The closest thing, a SR-71 launched drone, turned
out to be a hard enough problem that the drones were refitted to
B-52 under wing launching.

Redesigning the X-15 to be a weapons delivery platform would result
in a vehicle with only a vague resemblance to the X-15 rather than
being a simple modification. It would be sort of like modifying your
car by jacking up the radiator cap and driving a new car under it.

>Seriously.  My point was that the X-15 was qualifying astronauts
>at a rate that I think the SHuttle only passed recently.

X-15 made something under 200 flights, many with the same pilot,
and not all X-15 flights were for altitude, many were speed runs.
I had a listing around here somewhere of X-15 pilots who received
astronaut wings but I can't find it right now. I recall the number
was under a dozen.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

------------------------------

Date: 22 Feb 1993 21:05:10 GMT
From: Doug Mohney <[e-mail]>
Subject: Nobody cares about Fred?
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (John Andrusiak) writes:

>In fact, materials engineering seems to be a better understood science
>that software engineering, if only because materials engineering has been
>around longer.

Software engineering yahhh... Kinda like "military intelligence" hmmm?




                    I have talked to Ehud, and lived.
  -- >                  [e-mail]                        < --

------------------------------

Date: Mon, 22 Feb 1993 22:11:02 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Nobody cares about Fred?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Thomas Clarke) writes:
>In article <[e-mail]>
>[e-mail] writes:
>>  There is a great
>> deal of difference in just being up there to fly the flag and going up there
>> to do real work and real research.
>
>What is "real reasearch"?  I recall that during last summer's FRED budget
>battles, several scientific societies (after much soul searching, no
>doubt) recommended that FRED be cancelled since it did not provide the
>sort of capabilities they needed for their research.

There has been longstanding hostility to the space program by many
scientists. Park's American Physical Society newsletter comes
immediately to mind. Much of this hostility seems from here to be
based on envy of the space program budget. Some seem to feel that
killing Fred will mean more money for their pet projects. There's
little evidence that this would be the case. SSC has come under
similar attacks for similar reasons.

I don't think it's possible to defend Fred on the basis of sheer
volume of published papers, or on the number of research grants
it will generate. Yet these are the measures many scientific
societies apply to projects. Fred is at least as much an engineering
testbed and technology demonstrator as it is a scientific research
facility. That can sometimes upset the "pure" science types who would
rather see the money spent on research grants. But the funding process
doesn't work that way. It's not either/or, it's spend or not spend,
and each program has to stand on it's own *political* merits when it
lines up at the trough.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

------------------------------

Date: Mon, 22 Feb 1993 21:54:23 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Nobody cares about Fred?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>
>>    I'm confused again, Allen. Why do you say that "the Hare" (the US)
>>    thinks that refueling is too dangerous?
>
>Because when I asked an engineer working logistics at the Freedom program
>office why Freedom stationkeeping thrusters wouldn't be refueled in space
>he told me it was considered too dangerous.

Ok, but what did he *mean* by that? Too dangerous to Freedom to leave
years old valving and thrusters uninspected in orbit perhaps?

>>    refuel. The Freedom design, at least until Billary killed it, called
>>    for either refuelling or complete changeout of propulsion modules.
>
>The plan was to bring the whole mdoule back. This is far more expensive
>then refueling.

Is it? If the module is really modular, it would seem a simple exercise
to unplug it and plug in the replacement. Since the bulk of the thruster
is propellant storage, is it really that much more massive than refueling
tanks and transfer equipment? Seems to me that since Shuttle is coming
down anyway, it might as well return the thruster modules for easier on
ground inspection, repair, and refilling. It would be bringing the empty
refueling tankage in any event. Perhaps the module changeout can even be
accomplished by the arm with no need for EVA and it's pre-breathe costs.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

------------------------------

Date: Tue, 23 Feb 1993 01:08:23 GMT
From: "Peter L. Jackson" <[e-mail]>
Subject: Regularly updated Weather images ... help with HDF format?
Newsgroups: sci.space,sci.geo.meteorology

In article <[e-mail]> [e-mail] (tommy pickles) writes:

>   Howdy!
>       Thanks, Milo.  Can't wait to try this out.  I have
>   a <dumb?> question about HDF files.  What are they?  I know
>   our NCAR Graphics package has some hdf filters for the
>   ftrans and ctrans routines -- can I feed your HDF files
>   to the NCARG stuff?  Also, we have a few "hdf2xxx" conversion
>   programs on our Sun 4/470.  Can I use these on your HDF files?
>   Lastly, are there any other <free?> programs on the net
>   for manipulating HDF files?  Thanks for the help.
>   --
>   <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>   Pat Hayes, Meteorology, Texas A&M University...<whoop!>[e-mail]
>   O&M 1008, TAMU, CS, TX 77843-3150....days:[phone] fax:[phone]

HDF is Hierarchical Data Format, and was invented by the National
Center for Supercomputer Applications (NCSA) as a way of storing self
describing image and numerical data files. NSCA has written ximage,
which is freely available for unix workstations to analyse / display
hdf files. Also, the NCSA spinoff company, Spyglass, has a whole suite
of software running on mac and sgi platforms which also use data files
in hdf.

--
========================================================================
Peter Jackson | UWO Geography | phone [phone]x5024 | fax [phone]

------------------------------

Date: 22 Feb 93 23:59:04 GMT
From: Bruce Dunn <[e-mail]>
Subject: Shuttle refueling
Newsgroups: sci.space

        While the dregs of propellant in the ET are not particularly easy to
use as a liquid, it would be very easy to draw hydrogen and oxygen gas from
the tanks.  If it were possible to accelerate a shuttle/ET/space station as a
unit (say at a boost of 0.01 G), then a small engine burning gaseous oxygen
and hydrogen could make use of the ET propellants for reboosting the station.

--
Bruce Dunn    Vancouver, Canada   [e-mail]

------------------------------

Date: 23 Feb 93 00:14:11 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Shuttle refueling was(Re: Sabatier Reactors.)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Gary Coffman) writes:
> In article <[e-mail]> [e-mail] (Pat) writes:
>>If i understand,  they did a simulation using nitrogen gas.
>>and it's nice, but they only did one or two experiments in 60
>>missions.  Sherzer is right on when he says every!  shuttle misison
>>should have carreid a couple of suits and had the astronauts out
>>there playing with hardware in vacuum.
>
> A precursor test was done with inert gases, but on flight 41-G
> Kathryn Sullivan and David Leestma did actual hydrazine transfers
> during a 3 hour EVA to test hoses, valves, and couplings to be
> used in future satellite refuelings. It worked perfectly, *several*
> times. Rumor has it that new military spy satellites are fitted with
> these couplings. A KH12 carries about 5,000 pounds of hydrazine, and
> when it runs out, the satellite can't be maneuvered over interesting
> targets anymore.

If memory serves, the Compton Gamma Ray Observatory is designed to  be
refueled by the Shuttle.  I think the engines use hydrazine, although
it's possible CGRO has a cold-gas system.

> When a system works just like you intended it to
> do, you don't need to test it on every flight.
[...]
> Fuel transfer has been done, it
> works, end of story. The only question remaining is, when is it
> cost effective? It may already be for spysats, but they aren't
> going to tell us.
[...]
> Throwing in an EVA just for the hell
> of it is really silly. With pre-breathe, it's very consuming of precious
> on orbit astronaut time. There has to be a pressing reason to do EVA.

Hmm... If, as NASA has announced and Allen Sherzer has "applauded,"
they want to gain EVA experience, it is not only useful to do even
simple and dumb EVA tasks, it is useful to *repeat* the same ones with
different astronauts.  This serves a dual purpose:  it gives you more
statistics for performance measurements on the task, and it gives
experience with it to more astronauts.  Both seem to me good reasons
to do lots of EVAs in an engineering program.  I expect we'll see much
more of the "spaceman's carry" and similar experiments.

> Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
> Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
> 534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
> Lawrenceville, GA 30244     |                     |

Overnight?

--
     O~~*           /_) ' / /   /_/ '  ,   ,  ' ,_  _           \|/
   - ~ -~~~~~~~~~~~/_) / / /   / / / (_) (_) / / / _\~~~~~~~~~~~zap!
 /       \                          (_) (_)                    / | \
 |       |     Bill Higgins   Fermi National Accelerator Laboratory
 \       /     Bitnet:     [e-mail]
   -   -       Internet:  [e-mail]
     ~         SPAN/Hepnet:      43011::HIGGINS

------------------------------

Date: 22 Feb 1993 22:41:41 GMT
From: Andy Cohen <[e-mail]>
Subject: SSTO/DC-X GIFs
Newsgroups: sci.space

Hi
I've uploaded two GIFs to :
    tezuka.rest.ri.cmu.edu [128.2.209.227]
    /pub/space

and to:
csd4.csd.uwm.edu:/pub/Misc

SSTOART.GIF is an artist's rendition of the production...i.e., full size
version...
SSTOFOTO.GIF is a photograph of the actual 1/3 scale model to be flown
along with some descriptive text which is short, yet informative....

Enjoy.....but keep in mind that this is an SDI project....not NASA.....
Get it?!  It's a shuttle killer......  Understand???   That is, don't
expect much support from a service which has all it's money riding on the
shuttle....

If and when it flies....if you want it....ya gotta PUSH for it....

------------------------------

Date: 22 Feb 93 21:20:49 GMT
From: [e-mail]
Subject: Stars in space pictures?
Newsgroups: sci.space

> In every space picture I've ever seen, like the ones of Earth, the Moon, the
> various planets, etc., I have never seen *stars*.  Shouldn't there be millions
> of stars showing all around in space?
>
> Scott

Stars arn't visible because the object in the forground is SO much brighter.
You would have to overexpose the object in the forground to bring out the
stars.  An interesting point of you have PhotoShop or some other program for
enhancing photographic images, you can bring out the stars by running the
appropriate filters.  The results can be quite supprising sometimes.

Joseph A. Huwaldt
Aerospace Engineering, KU
[e-mail]

------------------------------

Date: Mon, 22 Feb 1993 21:16:47 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Wouldn't an earth to moon shuttle be better than fred?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Joe Cain) writes:
>In article <[e-mail]> [e-mail] writes:
>>In article <[e-mail]>, [e-mail] (Robert Ivan) writes:
>>|>
>>|>   It seems to me that having a earth to moon shuttle would be a far more
>>|> suitable use of resources. Something that could take a few people and cargo
>>|> out to the moon and back to earth orbit.  Okay, I know that somebody will
>>|> argue that a space station is needed in between.
>
>    NASA an most others agree that a space station is virtually
>useless as a staging point between the Earth and Moon or Mars. I
>brought this point up with one of the people in Goldin's entourage in
>Tampa in December. He told me that getting them in the proper position
>on a return is almost impossible. They thus have no plans to use a
>space station as an intermediate stop to or from any planet.

Direct return to Earth, using aerobraking, is certainly more efficient
in terms of fuel required than rendezvous with an orbiting station
for a small capsule. However, the navigation requirements are nearly
as stiff. The re-entry window is very narrow and was a concern during
Apollo's development. Since then we've demonstrated some rather spectacular
pin-point navigation in space. Note that since a lander is trying for
a specific spot on Earth's surface, it's re-entry window moves just
as surely as a station moves in orbit.

For large vehicles, however, it would seem that the additional penalty
for a re-entry shield, and re-entry shape, carried all the way out to
destination and return, would outweigh the modest extra navigational
constraints for station rendezvous. Von Braun thought, and some others
still do, that atmosphere/space craft were unhappy compromises and that
specialized systems better served the different needs of trans-atmospheric
travel and space travel. This concept requires a waypoint transfer system
in orbit. Whether that's a simple rendezvous, as with the Apollo LM and
command module in Lunar orbit, or a complex docking and refit center such
as a proposed space station, would seem to depend on the planned frequency
of flights and on the size of the vehicles more than on the difficulty of
navigation.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

------------------------------

Date: 23 Feb 93 00:29:16 GMT
From: Dave Rickel <[e-mail]>
Subject: Wouldn't an earth to moon shuttle be better than fred?
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Robert Ivan) writes:
|>   It seems to me that having a earth to moon shuttle would be a far more
|> suitable use of resources.

Well, why should we have an Earth-moon shuttle if nobody wants to go to the
moon (or at least, if nobody who has any money wants to go to the moon)?

How do you fuel/refuel the beast?  If you aren't using aerobraking at the
earthside, you've got on the order of 8 km/sec delta v for a round trip.
That's on the same order of as much as it took to achieve orbit in the first
place.  If you are doing aerobraking, the delta v goes down, but you have to
worry about inspecting/replacing your heat shield after transfer into LEO.


david rickel
[e-mail]

------------------------------

Date: Tue, 23 Feb 93 17:01:15 EST
From: [e-mail]

Joint ESA/CNES Press Release No. 07.93
Paris, 23 February 1993

FIRST ARIANE-5 SOLID BOOSTER TEST SCORES WELL

Analysis of the main parameters recorded during the first test, on
16 February, of the solid-propellant booster for ESA's Ariane-5
launcher confirms that all went well.  In particular, the pressure
and temperature values match predictions.  Visual inspection has
shown that all the booster parts are in good condition, i.e. the
thermal protection, igniter, nozzle throat, etc.

These good results, which will be consolidated by a detailed
analysis of all 600 measurements taken during the firing, mean
that the Ariane-5 launcher development plan can be confirmed,
leading to a first launch in October 1995.  The plan comprises 7
other tests on the booster teststand, to be carried out every three
and a half months on average.

The test was carried out under the responsibility of
EUROPROPULSION*, with CNES** in overall charge.  The P 230
booster is part of ESA'S Ariane-5 programme, the Agency having
delegated CNES prime contractor.

*       a joint subsidiary of BPD Difesa e Spazio (Italy) and the
        Socit Europenne de Propulsion (France)
**      Centre National d'Etudes Spatiales (France)




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End of Space Digest Volume 16 : Issue 219
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