Aucbvax.5421
fa.space
utzoo!decvax!ucbvax!space
Wed Dec 9 03:49:46 1981
SPACE Digest V2 #54
>From OTA@S1-A Wed Dec 9 03:42:46 1981
SPACE Digest Volume 2 : Issue 54
Today's Topics:
Arthur Kantrowitz talk at Harvard
getting there (high power)
Galileo cut
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From: BRUC@MIT-ML
Date: 12/08/81 12:27:28
Subject: Arthur Kantrowitz talk at Harvard
BRUC@MIT-ML 12/08/81 12:27:28 Re: Arthur Kantrowitz talk at Harvard
To: Space-Enthusiasts at MIT-MC
Last night, Arthur Kantrowitz gave a talk at Harvard titled,
"What is Holding Back the Utilitization of Outer Space?". He made a
number of provocative statements that should prove interesting to those
(such as myself) who hadn't heard them before.
He opened his talk by looking at societal environment for space
utilization. In the thirties, Bernal, a physicist, foresaw huge numbers
of people living in spheres in space colonies. At the time, getting into
orbit was the problem. Now, we can get into orbit, but the future for
space is cloudly (much to all our chagrin).
NASA and the politics behind its expenditures provide a partial
explanation of what's happening. In his view, the goal of making space
reasonably accessible was secondary to goal of pumping money and high
technology into the states which held Lyndon Johnson's allegiance,
particularly Texas. Second, he implied that the pursuit of safety in the
Apollo program may have been excessive. He pointed out that the only men
who were killed died in a safety exercise rather than in space.
He then considered the financial and energetic barriers to
getting into low earth orbit. If you calculate the kinetic energy of one
pound at orbital velocity 100 miles up, you get an energy value of 4.5
kwh/lb (25 cents!!). The shuttle will cost in the high hundreds of
dollars per pound. Amortizing the development cost ($10 billion) of the
shuttle will take on the order of 1000 flights because the savings in
cost is only a couple of hundred dollars per pound.
What is wrong with the shuttle, then? First, it has wings. If an
orbiter had a more compact shape, the reentry would not be such a
problem. It would land by parachute and the final impact would be
dissipated by some sort of crushable material. Such a design would not
preclude reusability of most of the hardware. Why does it have wings?
Politics. Only the aerospace companies would get a contract to build it.
The shuttle keeps NASA in business these days; without it, they'd be a
shell.
What are better ways? He suggested three. All of these are
"railways to space" as he put it. Without such a system, space will
never be well utilized.
1) The big dumb booster. A very large booster that could be
built with standard metals (he suggested the Chicago Bridge and Iron
Works as prime contractor). He didn't give many details on it.
2) Mass driver to orbital speeds on earth. He suggested that a
properly designed projectile (telegraph poles) would not have drag high
enough to keep it from orbit. The work he described was done by Cohen
(spelling?).
3) Laser launching system. He worked on this at Avco Everett.
You use a laser to heat a gas to whatever temperature you require and
shoot it out the back. Presumably, the laser would be on the ground
shooting at the capsule going into orbit (See J. Pournelle's High
Justice for a good sf story based on this idea.) You'd need about a
gigawatt of power to launch one ton into orbit.
A fair amount of research was done on this concept. Dr.
Kantrowitz demonstrated a small version of this system to von Braun. His
reaction was one of interest, but he asked that it not be publicized as
the enemies of the shuttle would then have a weapon to kill the shuttle
off without having something better to replace it.
But what will really make people go into space? Pressures from
society. The threat of nuclear war, limits to growth. He suggested that
if pessimistic and optimistic visionaries would talk to each other
rather than past each other, space is the obvious solution to many of
our problems.
After the talk, there was some discussion. One of the
interesting points he made was that the space based, laser ballistic
defense system looked very good to him. He was upset at Tsipis for his
article in the December Scientific American because he left out
possibilities that destroy the arguments he presented in the article. In
particular, the power for such a system could also come from the ground
via a mirror in higher orbit, or a larger nuclear power plant. He felt
that such a large station could be easily shielded from the attack of
another such large station (by mass), yet it would still be effective
against missiles which have a thin shell.
I found the talk fascinating. In particular, I was struck by the
idea that the laser launching system could probably be developed at
roughly the same cost as the shuttle. We blew it with the shuttle in a
sense. For the same price we could have been putting pounds into orbit
for at least a tenth the cost we'll be paying for the next decade.
Bob Bruccoleri
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Date: 8 Dec 1981 12:30:50-EST
From: csin!cjh at CCA-UNIX
To: Lynn.ES at PARC-MAXC
Subject: getting there (high power)
Cc: space at mit-mc
Do you really believe that nuclear or electric power will be feasible
for earth launches any time in the forseeable future? Most of the
schemas I've seen for [electric] (e.g., ion-powered) rockets talk about
low levels of continuous thrust, suitable for interplanetary travel.
Note that you still have to have reaction mass from somewhere (although I
suppose you could get as much as 20 miles up using ambient air as a reaction
mass, which would help).
I'm willing to look at long shots to get into space, but not to plan on
miracles when proejcting what space will be like.
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Date: 9 Dec 1981 0014-EST
From: J. Noel Chiappa <JNC MIT-XX AT>
Subject: Galileo cut
To: space at MIT-MC
cc: JNC at MIT-XX
'Galileo Juptier orbiter/probe and 50% of NASA's aeronautics
program have been cut from the agency's Fiscal 1983 budget by the
OMB. The $300 million already invested in Galileo would be lost as
well as about 1,200 jobs at the JPL. the move would end U.S. planetary
exploration, a concept the White House supports. Aeronautics cuts
would have a long term impact on national aeronautical capability,
especially in competing with other world markets, and NASA administrator
Beggs is expected to appeal directly to Reagan.
White House OSTP, headed by presidential science advisor George
Keyworth, has taken a position that the U.S. planetary program should be
halted because of what the staff believes is limited 'show-biz' results
compared with other scientific investigations.'
There's more, specifically an article about the the House/Senate
conference on the NASA budget, in which the legislature seemed pretty
pro-NASA. The had money for a continuing option on two spacecraft for
the ISPM, Galileo, aero research, orbiting infrared telescope, and (if
I read this right) some for a fifth orbiter. An attempt to add Halley's
lost.
How many B-1's does it take to suppport a civilian U.S. space
program? (Hint: same number as average administration member's IQ.)
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End of SPACE Digest
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