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From: dietz@SLB-DOLL.CSNET (Paul Dietz)
Newsgroups: net.space
Subject: Scuttle the Shuttle?
Message-ID: <8601301636.AA04800@s1-b.arpa>
Date: Thu, 30-Jan-86 17:23:21 EST
Article-I.D.: s1-b.8601301636.AA04800
Posted: Thu Jan 30 17:23:21 1986
Date-Received: Sat, 1-Feb-86 06:48:58 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 62

Just when you thought things couldn't get worse, they did.  The shuttle
was plagued by delays and bad economics, and now its a killer.  It's
time to take a long hard look at the shuttle and strip away the myth
from the reality.

Some myths:  that the shuttle is a cheap way of delivering cargo to
orbit, that manned shuttle missions are somehow bringing us closer to
real exploitation of space, that manned missions in the shuttle can
accomplish things economically that can't be done by robots.

I addressed the first myth several months ago.  The NY Times mentioned
in today's paper that the cost of shuttle cargo ($2000 to $2500/lb to
LEO) makes almost all space manufacturing uneconomical.  NASA has
received almost no positive response from industry, just some companies
exploiting NASA's subsidized rates for research to do work feeding back
to ground based processes.

The shuttle has also been less reliable and more expensive than unmanned
boosters for lifting satellites in orbit.  Although the putative cause
of many of these satellite failures has been PAM motor or satellite
malfunctions, have you noticed how many problems there have been with
experiments in the shuttle cargo bay?  I suspect the vibrations during
shuttle launch from the SRB's are damaging the payloads.  This is
one of the theories about what destroyed Challenger -- combustion
instabilities in the SRB's could induce vibrations in the shuttle
that could lead to structural failure.

The second myth: that the shuttle is somehow advancing the real
exploitation of space.  This a curious inversion of logic.  Clearly,
when space has been fully exploited there will be lots of people up
there, it doesn't follow, though, that any scheme for sending people
into space moves us towards that goal.  Except for some sound (if
extremely expensive) research conducted in Spacelab, the shuttle has
done little for the advancement of space exploitation.

The third myth: that manned missions can accomplish things economically
that can't be done by robots.  This is true in the long term (unless AI
really succeeds), but in the short term (read: for the rest of this
century, at least) there is little that can be done in space
economically that robots and teleoperated manipulators can't do better.
Repair and maintenance of spacecraft in earth orbit, mining the moon,
exploration of the planets, manufacturing in low earth orbit are all
better done by robots and remotely controlled manipulators, simply
because they don't breath or eat, don't die of radiation from solar
flares, and can be launched by supposedly less reliable expendable
boosters, can be controlled from the ground 24 hours a day and can be
left in space for years.


So, what should be done with the shuttles?  Just grounding them is a bit
excessive, but they are currently unsafe and uneconomical.   The
following might make sense: convert one shuttle to purely manned mode;
beef up its structure so that it's too heavy to carry much cargo but
can carry people into orbit.  The other two shuttles can be adapted to
as unmanned reusable cargo vehicles.  Strip out the cabin section and
replace it by a much smaller forward electronics bay.  Extend the
cargo bay forward, or just leave that space empty.  This converted
vehicle would take off and land semiautonomously, and would be used to
deploy satellites.  It could conceivably carry much more cargo and,
if it prangs after 25 flights no one would be killed.  Perhaps all
three can be adapted for unmanned use, but NASA probably wants to keep
one vehicle around for congressional joyrides.