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From: KFL@MIT-MC.ARPA ("Keith F. Lynch")
Newsgroups: net.space
Subject: Trans-atmospheric vehicle
Message-ID: <[MC.LCS.MIT.EDU].768142.851229.KFL>
Date: Sun, 29-Dec-85 16:56:18 EST
Article-I.D.: <[MC.LCS.MIT.EDU].768142.851229.KFL>
Posted: Sun Dec 29 16:56:18 1985
Date-Received: Mon, 30-Dec-85 02:19:27 EST
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    From: unmvax!nmtvax!wildstar@ucbvax.berkeley.edu

    Has anyone ever thought about the environmental impact that an air-
    breathing x-atmos vehicle is likely to cause?  ...what would 
    happen to the atmosphere if it is relied on as oxidizer?

  Not much.  The amount of oxygen in the atmosphere is enormous.
Since the fuel would probably be hydrogen, the only combustion product
would be water vapor.  Since the hydrogen for the fuel was gotten from
water in the first place, there is really no net change to the
environment.
  The great heat of the combustion could cause some nitrogen and
oxygen in the atmosphere to combine to form trace amounts of nitrogen
oxides.  This is the same thing that happens whenever there is
lightning.  And the energy in one fair-sized thunderstorm is far more
than the energy of a shuttle launch.
  The fuel needs of the trans-atmospheric vehicle would be far less
than that of a vehicle which has its oxidizer on board.  And every
space vehicle, to date, has burned the most and the fastest, when
closest to the ground.  And I have never heard of any adverse effects
from the combustion, except for temporary heating of the ground (along
with any unfortunate small animals) within a mile or two of the launch
pad.  In particular, I have never heard of any acid rain problem in
southern Florida, or any pollution problem there that has anything to
do with the space program.
  If you are concerned about acid rain, it is better to worry about
the billions of tons of sulfur-rich coal that are burned every year in
the midwest than to worry about the thousands of tons (millions of
times less) of clean rocket fuel burned each year.
  The Orion program was cancelled largely due to environmental
concerns.  The Orion program proposed launches to be made by
detonating hundreds of nuclear bombs.  Had this program continued, we
would probably have the solar system in our grasp today.  We would
also have several thousand extra fatal cancers.  It was decided that
it was not worth it.  I agree with that decision.  Though it should be
pointed out that smoking causes about 100 times the deaths that Orion
would have.
  Environmentalists did us all a service by forcing Orion to be
cancelled.  But if environmentalists object to everything, they
quickly lose their credibility.  Expansion into space is necessary for
the future of our species.  Without space, we are all doomed.  Blind
opposition to all forms of space travel is counter-survival.
  If environmentalists wish to improve our environment, they should
concern themselves primarily with smoking.  Automobiles and alcohol
would be tied for a distant second.  And burning coal would be a very
distant third.  Nothing else is even in the running.
								...Keith