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From: gsh7w@astsun8.astro.Virginia.EDU (Greg S. Hennessy)
Newsgroups: sci.space.shuttle
Subject: Re: Hydrogen leak test
Message-ID: <1990Aug10.154622.9796@murdoch.acc.Virginia.EDU>
Date: 10 Aug 90 15:46:22 GMT
References: <27929@netnews.upenn.edu>
Sender: news@murdoch.acc.Virginia.EDU
Organization: University of Virginia
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Jack Vinson writes:
#Hello everyone,
#	I saw a very small blurb in the paper this past Sunday which
#said NASA was so confident it had cleared up the hydrogen leak in the
#shuttles that it wouldn't be testing for the leak again.  Is this true?
#I don't think this makes sense, unless their tests during the fix were
#extensive enough to preclude the pre-flight tests.

What got reported to the press is not exactly what happened. The
tanking test is not going to be done, because it takes up five days,
and would not really give any useful data. That is, if the shuttle
passes the test, that does not mean it will NOT leak on the pad, but
does mean that the launch window is only about 15 days long. If you
don't do the test then the launch window is about 20 days. In either
case, the important thing is if the shuttle leaks on the pad, and the
test won't definitely tell us that. The existing procedures are
sufficient to detect a leaky shuttle on the pad, so safety is not
compromised. 

Therefore, since the tanking test is of marginal utility, while
imposing a large time constraint, it will not be done. Of course, if
it turns out that Columbia leaks on the pad, the mission will be
delayed till about November, and NASA will look quite foolish.

I don't speak for NASA.

--
-Greg Hennessy, University of Virginia
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