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From: stealth@caen.engin.umich.edu (Mike Peltier)
Newsgroups: sci.space.shuttle
Subject: Re: How do they get it pointing up?
Message-ID: <473bfa27.b617@bear.engin.umich.edu>
Date: 5 Dec 89 01:29:00 GMT
References: <1989Nov23.165606.27671@utzoo.uucp> <117.UUL1.3#5131@mvac23.UUCP>
Reply-To: stealth@caen.engin.umich.edu (Mike Peltier)
Organization: University of Michigan Engineering:  Ann Arbor, Michigan
Lines: 20

In article <117.UUL1.3#5131@mvac23.UUCP> mvac23!thomas@udel.edu writes:
>
>I assume that one of the reasons that shuttle's engines start before the
>solid boosters is to help counteract the tendency of the whole thing to
>fall on the orbiter's back?
>

Wrong-o.  Give these engineers some credit, willya?  I'm going to be
one of them in a few years...  The reason the SME's are lit first is
simply that you can turn them off, while the SRBs are considerably
more difficult to snuff.  Recall that launch a couple of years back
where the SMEs fired for about a second and a half and then shut down?
If that had happened after the SRBs were lit, there would have been
considerably more problems to deal with.

-- 
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Michael V. Peltier         | Computer Aided Engineering Network      
1420 King George Blvd.     | University of Michigan,  Ann Arbor       
Ann Arbor, MI  48104-6924  |    stealth@caen.engin.umich.edu