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From: lwe3207@acf4.UUCP
Newsgroups: net.columbia
Subject: Re: Getting it back to the Cape
Message-ID: <11700004@acf4.UUCP>
Date: Sun, 22-Apr-84 22:52:00 EST
Article-I.D.: acf4.11700004
Posted: Sun Apr 22 22:52:00 1984
Date-Received: Tue, 17-Apr-84 07:16:19 EST
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Organization: New York University
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Nf-From: acf4!lwe3207    Apr 15 22:52:00 1984


[]

(More response.)

I didn't consider the fact that the 747 is to the Shuttle as a glider is
to an F-14: i.e., the glider has more lift.  So clearly the 747 has a lot
more appropriate lift for the lower atmosphere, and hence is more fuel-
efficient a priori than a powered shuttle.  The corollary being that if
you tried to drop a 747 at 17K-knots out of orbit, it would melt while the
wings were tearing off.  (I guess the cabin pressurization in an airliner
comes from the jet engines intake/compressors, so the passengers in said
747 would also have suffocated by that time.  But it would be amusing to
film such an event: you could ferry the parts of the 747 up into orbit,
assemble it, and then "push it backwards" until it was below orbital
velocity.  Bugs Bunny could be inside, searching madly for the airbrakes,
while robots with parachutes jumped out into the flaming void.)

I guess this will always be a tradeoff in aero vs. space craft, until the
materials technology for the skin (heat-reflective) and infrastructure
(tough but light) are so good that you can make an orbiter capable of
re-entry which also has a sufficiently good lift coefficient to be economical
for self-powered flight in the lower atmosphere.

Lars Ericson
cmcl2!acf4!lwe3207