Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!uw-june!uw-entropy!dataio!pilchuck!seahcx!phred!petej
From: petej@phred.UUCP (Pete Jarvis)
Newsgroups: sci.space.shuttle
Subject: Re: holds in countdown
Message-ID: <2515@phred.UUCP>
Date: 27 Mar 89 15:55:30 GMT
References: <8.UUL1.3#5131@mvac.UUCP> <1989Mar22.175252.1343@utzoo.uucp>
Reply-To: petej@phred.UUCP (Pete Jarvis)
Organization: <1989Mar22.175252.1343@utzoo.uucp>o
Lines: 16

In article <1989Mar22.175252.1343@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>
>There is no particularly good reason for this; it's just NASA tradition
>as far as I know.
>-- 
>Welcome to Mars!  Your         |     Henry Spencer at U of Toronto Zoology
>passport and visa, comrade?    | uunet!attcan!utzoo!henry henry@zoo.toronto.edu

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.
If the activity runs over the allotted time, then, depending on where the 
count is, they can decide whether or not to proceed at that point or re-cycle
the launch sequence computer to an earlier mode.

Peter Jarvis - Physio-Control -- Redmond, WA.