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Subject: SPACE Digest V10 #243

SPACE Digest                                     Volume 10 : Issue 243

Today's Topics:
              Re: Future Space Missions
              Re: Future Space Missions
              Re: Future Space Missions
              Re: Future Space Missions
----------------------------------------------------------------------

Date: 13 Nov 89 13:50:54 GMT
From: att!cbnewsh![e-mail]  (lawrence.m.geary)
Subject: Re: Future Space Missions

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>>... Why aren't there plans to use appropriate boosters?
#
#Because there are none.  Although it is fashionable to malign the Shuttle
#as a planetary launcher, the Shuttle/IUS combination is the heaviest
#booster available (outside the Soviet Union).  Titan/Centaur is in second
#place by a considerable margin.
...

Didn't we use Titan/Centaur to launch the Voyagers?

#The only available-now launcher that could do a better job on Cassini
#would be Energia.

Available now is not the issue. Cassini is launching toward the end of
the century. We succeeded in going from initial concept to a moon landing
in less time than that. Now you are confirming my suspicions that we are
dead in the water as far as progress on ELV's goes. No program. No plan.

Buying launches on Energia from the USSR would be in our mutual interest;
it's one of the few things they can sell that we need. That probably
guarantees that we'll never do it.
--

     [e-mail]    Think globally ... Post locally    att!hoqax!lmg

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

Date: 13 Nov 89 22:57:11 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Future Space Missions

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Tom Neff) writes:
>>>The only available-now launcher that could do a better job on Cassini
>>>would be Energia.  The Soviets have no superstitious fear of cryogenic
>>>upper stages ...
>>
>>Whoa, neither do we, if we're talking upper stages on unmanned
>>boosters.  The knock on Shuttle/Centaur was taking that cryogenic upper
>>stage up on the flatbed of a human crewed truck!
>
>Said flatbed sits on nearly a kiloton of cryogenic fuels at launch.  Every
>US manned spacecraft except Gemini has done likewise, on varying scales.
>Nobody is heard to object to large quantities of solid fuels or storable
>liquid fuels in the payload bay.  Those damned roman candles it uses ...
>
>Superstitious fear is what I called it, and that's what it is.

Henry sounds mad!  That's bad.  I'm sad.  ;-)

However he sidestepped the point, which was that the US CANNOT be
accused of having some "superstitious fear of cryogenic upper stages"
compared to the brave Soviets who dare launch unmanned rockets with
cryogenic upper stages.  We're happy to do this!  What we will not do is
take a cryogenic rocket up as a Shuttle payload, and there is no
evidence so far that the Soviets will either.  The difference is that
our heavy lifter requires a crew and theirs doesn't.

>>It was the astronaut
>>office, not armchair critics, that nicknamed it the "Death Star".  Who
>>got it cancelled?  A couple of guys named Young and Crippen...
>
>I don't recall Young refusing to assign crews to the June-1986 S/C missions,
>or any of the people assigned to them backing out.

The nickname and the cancellation were not contemporaneous.  The
nickname came about in 1984-5 when the missions were starting to train.
The insistence on switching to IUS came post-Challenger when astronaut
leverage at HQ was at its zenith.

>One should remember that specific astronauts, even the ones in charge,
>don't necessarily speak for all astronauts.

Right, which is why we use the words "in charge," not "in office."
For the Chief Astronaut always to "speak for all astronauts" would mean
requiring unanimous consent before anything got done!  Not in this man's
army... :-)

[further digression into who-wanted-to-fly deleted]

>I don't doubt that preparations for the 1986 S/C flights were a bit rushed
>and safety was taking second place, but I don't see anything inherently
>impossible about safely flying cryogenics in the shuttle payload bay.

Except that with *proper* care and attention being paid to safety and
reliability, and with an already hopelessly behind-schedule manifest, we
don't need more complicating, risk-laden factors tossed in.  Only the
safest and simplest mechanisms available ought to be permitted to occupy
OPF/VAB time.

>The real reason Shuttle/Centaur died and stayed dead -- unlike a number of
>other post-Challenger changes, like the tightened weight limits, which
>have since been eased off again -- was that it only had one customer who
>needed it badly, and this just wasn't enough political clout.  (Ulysses,
>not being American, naturally didn't count.)

Left unremarked here is that this may be plenty of reason!  Any risk you
can cut out with that small of an impact, you should.  Considering these
birds should have been flying on Saturns or a new unmanned heavylift
instead of STS in the first place, a position I think Henry's familiar
with :-), crocodile tears for Shuttle/Centaur at this point seem
incongruous.
--
"We must never forget that if the war in Vietnam    \ $   Tom Neff
is lost... the right of free speech will be          X    [e-mail]
extinguished throughout the world." -- RN 10/27/65  $ \   uunet!bfmny0!tneff

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

Date: 13 Nov 89 19:38:30 GMT
From: cs.utexas.edu!ut-emx![e-mail]  (Anita Cochran)
Subject: Re: Future Space Missions

In article <[e-mail]>, [e-mail] (Anita Cochran) writes:
> Galileo would have been fine with a shuttle launch as originally planned.
> However, when the Challenger blew, it was decided that the IUS was
> potentially too dangerous.  Thus, they went to the Centaur.

OOPS.  I blew this.  I got it backwards.  They were going to use the centaur
upper stage and got cold feet and ended up using the IUS.  My apologies
for screwing this up.

--
 Anita Cochran  uucp:  {noao, ut-sally, ut-emx}!utastro!anita
                arpa:  [e-mail]
                snail: Astronomy Dept., The Univ. of Texas, Austin, TX, 78712
                at&t:  [phone]

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

Date: 13 Nov 89 19:31:30 GMT
From: gem.mps.ohio-state.edu!uwm.edu!mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Future Space Missions

In article <[e-mail]> [e-mail] (Tom Neff) writes:
>>The only available-now launcher that could do a better job on Cassini
>>would be Energia.  The Soviets have no superstitious fear of cryogenic
>>upper stages ...
>
>Whoa, neither do we, if we're talking upper stages on unmanned
>boosters.  The knock on Shuttle/Centaur was taking that cryogenic upper
>stage up on the flatbed of a human crewed truck!

Said flatbed sits on nearly a kiloton of cryogenic fuels at launch.  Every
US manned spacecraft except Gemini has done likewise, on varying scales.
Nobody is heard to object to large quantities of solid fuels or storable
liquid fuels in the payload bay.  Those damned roman candles it uses for
boosters are considered acceptably safe for continued use -- not only are
they still in use, there are no plans to replace them with something safer.
Yet cryogenic fuels in the payload bay are a safety-engineering problem
which is somehow utterly beyond our ability to solve.

Superstitious fear is what I called it, and that's what it is.

>It was the astronaut
>office, not armchair critics, that nicknamed it the "Death Star".  Who
>got it cancelled?  A couple of guys named Young and Crippen...

I don't recall Young refusing to assign crews to the June-1986 S/C missions,
or any of the people assigned to them backing out.

One should remember that specific astronauts, even the ones in charge,
don't necessarily speak for all astronauts.  And official public statements
usually have a large element of politics in them.  As witness Sally Ride's
post-Challenger pronouncement that none of the astronauts were willing to
fly the shuttle until it was fixed -- verifiably a lie unless you interpret
it *really* broadly.  (All the astronauts wanted things fixed, but a fair
number were willing to fly without waiting 2.5 years for the definitive
fixes, given an urgent payload and some obvious precautions.  A lot of
them are test pilots, remember -- flying quick-fix interim versions is
nothing new to them.)

I don't doubt that preparations for the 1986 S/C flights were a bit rushed
and safety was taking second place, but I don't see anything inherently
impossible about safely flying cryogenics in the shuttle payload bay.

The real reason Shuttle/Centaur died and stayed dead -- unlike a number of
other post-Challenger changes, like the tightened weight limits, which
have since been eased off again -- was that it only had one customer who
needed it badly, and this just wasn't enough political clout.  (Ulysses,
not being American, naturally didn't count.)
--
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
megabyte of flaming.           | uunet!attcan!utzoo!henry [e-mail]

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

End of SPACE Digest V10 #243
*******************