Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: holds in countdown
Message-ID: <1989Mar28.233955.1843@utzoo.uucp>
Organization: U of Toronto Zoology
References: <8.UUL1.3#5131@mvac.UUCP> <1989Mar22.175252.1343@utzoo.uucp> <2515@phred.UUCP>
Date: Tue, 28 Mar 89 23:39:55 GMT

In article <2515@phred.UUCP> petej@phred.UUCP (Pete Jarvis) writes:
>>There is no particularly good reason for this; it's just NASA tradition
>>as far as I know.
>
>The buil-in holds are not there because of NASA tradition. They have a purpose
>in life. Built-in holds are designed into the count at key points in the
>launch activity sequence where they may need to do some catch-up activity...

You miss the point.  That's an excellent reason for having some slack time.
The original question, though, was why the countdown clock stops during the
reserve time.  There's no obvious reason why it couldn't keep counting --
the lengths of those periods are fixed and predictable if nothing goes wrong.
It's a bit silly to have the clock stopping and starting when everything is
going according to plan.
-- 
Welcome to Mars!  Your         |     Henry Spencer at U of Toronto Zoology
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