Path: utzoo!attcan!utgpu!watmath!att!dptg!rutgers!netnews.upenn.edu!linc.cis.upenn.edu!rubinoff
From: rubinoff@linc.cis.upenn.edu (Robert Rubinoff)
Newsgroups: sci.space.shuttle
Subject: Re: Why 3 SSME's?
Message-ID: <14647@netnews.upenn.edu>
Date: 21 Sep 89 17:25:52 GMT
References: <24@loop.UUCP>
Sender: news@netnews.upenn.edu
Reply-To: rubinoff@linc.cis.upenn.edu (Robert Rubinoff)
Organization: University of Pennsylvania
Lines: 10

Well, for one thing, it means that if one engine fails, the other two may
still be able to get the shuttle to orbit.  This has in fact happened at
least once.  With one engine, if it cuts out, you've got yourself a sub-orbital
glider.

In general redundant systems are a good idea.  The flip side is that you may
have three times as many possibilities of catastrophic failure, but that's
not a trade-off I can make judgements on.

   Robert