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From: craig@think.ARPA (Craig Stanfill)
Newsgroups: net.space
Subject: What Now?
Message-ID: <4127@think.ARPA>
Date: Wed, 29-Jan-86 22:04:42 EST
Article-I.D.: think.4127
Posted: Wed Jan 29 22:04:42 1986
Date-Received: Sat, 1-Feb-86 01:19:27 EST
Reply-To: craig@think.UUCP (Craig Stanfill)
Organization: Thinking Machines, Cambridge, MA
Lines: 75

References:

In the aftermath of Challenger's loss, we have to examine
the shuttle program, and answer the question ``where do we
go from here?''  First, I am (like most Americans) committed
to the manned space program.  I think we have a future in
space, and the sooner we learn the technology needed to
conquer space the better.  Some important issues.

1.  As transportation from earth to orbit for payloads, is
    the STS economically justified?  I include in this
    dollar cost, cost due to delay when the STS cannot get
    off the ground, and cost due to payload loss when the
    launch vehicle fails (a significant problem with
    ARIENNE, and now alas with STS).

2.  Can the shuttle be fixed?  Perhaps NASA will figure out
    what went wrong, and correct the problem.  But more
    distressing, the shuttle is very complex.  Will there be
    more losses as new problems crop up?  STS was built as
    well as we know how, but it still suffers from many
    failures.  Most of these failures have resulted in
    nothing more than delayed flights;  some have come close
    to causing disaster; now we have a catastrophic failure.
    But then, who knows how many Saturns we would have lost
    if we had flown 25 missions with them.

3.  Do we have a choice?  How long can we afford to be
    without the Shuttle?  The military and civilian space
    programs are utterly dependent on the Shuttle.  The
    delays in Apollo (after the fire in I and the explosion
    in XIII) delayed only Apollo, but a delay in the Shuttle
    delays everything we are doing in space.

4.  Are we willing to risk more orbiters and more crews?

I welcome other opinions.  Here are my own.

First, the value of the Shuttle is as a means of perfecting
space technology.  The fact that payload fees pay for part
of its cost is icing on the cake.  I don't care much if it
loses money in the short run; in the long run what we learn
by flying the Shuttle is more than worth the cost.  

Second, I think the Shuttle can be fixed, and that it will
ultimately be reliable.  In any system as complex as the
Shuttle, it is impossible to get everything perfect on the
drawing board, so you have to keep trying the system out and
fixing bugs as they appear.  Whatever killed Challenger was
probably a small mistake.  Commercial airlines have much
larger safety factors in their design, but noone would
certify an airliner on the basis of 24 flights.  Airliners
continue to crash, in any event; new bugs are always being
found. 

Third, there is little alternative to the current STS.
Designing a new one is out of the question at this point;
if we did, there is no guarantee that it would be more
reliable.  It would certainly have to be at least as
complex.  Expendable boosters are an alternative, but
satellites would have to be redesigned, and this takes time.
ARIENNE is booked up, and there is a very small supply  of
other boosters.  Perhaps some aging TITAN II's being wasted
sitting in silos...

Fourth, it is unthinkable to needlessly risk orbiters and
crews.  NASA's credibility is on the line: their first
priority has always been flight safety, as it should be.
It should not fly until everything possible has been done to
fix the STS.

I think, then, that the following is in order.  First, find
the specific cause of this failure, and fix it.  Second,
evaluate the design of the STS, from top to bottom, and try
to find residual problems before we find one the hard way.
This might ground us for a year.  Third, build three more
orbiters.  We'll need them.