Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!asuvax!noao!arizona!kevin
From: kevin@cs.arizona.edu (Kevin Strietzel)
Newsgroups: sci.space.shuttle
Subject: Shuttle engine failure on the pad
Keywords: shuttle engine failure
Message-ID: <140@caslon.cs.arizona.edu>
Date: 16 Mar 90 21:12:27 GMT
Distribution: usa
Organization: U of Arizona CS Dept, Tucson
Lines: 37

Here's a query that's been bumping around my skull for a few years now:

What happens if one SRB ignites, but the second won't go?
Or one (or more) of the SSME's won't go?

Here are my initial thoughts:

I assume it's disaster time.

It *might* be able to leave the pad: my numbers claim it could get off the pad
(thrust > weight) with only the SRB's, but acceleration would be way down, so
it probably wouldn't get high enough to do anything useful.  If only one SSME
failed, you probably couldn't make orbit, but you could probably get high and
far enough to abort and land somewhere.

Presumably the pad would melt and/or burn if it just sat there -- if that's
even possible.  I can't remember if the shuttle is held down by anything
besides gravity at engine ignition time.  If you could physically hold the
shuttle down, would the torque of a single SRB flip the whole pad on its side?

Seems like an SRB could separate on the pad, and it'd leave pretty quick
without a shuttle holding it down, and they're slightly steerable.  But don't
they help support the orbiter on the pad?  And isn't its exhaust going to make
a mess of the shuttle, despite quick departure?  And I'd guess their steering
system is totally dependent on the orbiter's computers, and even if it weren't,
would it be stable solo?

Have I answered my own question?

Any comments would be useful.

	Kevin
-- 
Kevin Strietzel, CS Department, University of Arizona, Tucson, AZ
	Internet:	kevin@cs.arizona.edu
	UUCP:		...!{lots of places}!arizona!kevin
It's easy to pass the buck -- especially to someone who wants it!