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Path: utzoo!watmath!clyde!burl!ulysses!allegra!alice!alb
From: alb@alice.UUCP (Adam L. Buchsbaum)
Newsgroups: net.columbia
Subject: Launch Aborted
Message-ID: <3987@alice.UUCP>
Date: Sat, 13-Jul-85 01:40:18 EDT
Article-I.D.: alice.3987
Posted: Sat Jul 13 01:40:18 1985
Date-Received: Sat, 13-Jul-85 16:40:16 EDT
Organization: Bell Labs, Murray Hill
Lines: 16

The Challenger's launch attempt was aborted today, just
three seconds before SRB ignition.  In a near replay of
the abort last summer, a valve that regulates the flow
of hydrogen into the Number 2 Engine did not respond to
its primary control circuit.  A backup circuit sent the
proper command 40 milliseconds after the failure was
detected, but by that time, the ground sequence computer
decided to abort the launch -- NASA rules forbid a launch
unless all systems, including redundancies, are functioning,
so that backups will be available once in flight.  At the
time of the abort, two engines were at full power, while
the Number 2 Engine was near it.  A water spray system,
installed after last summer's abort and proceeding fire,
activated, but there was no fire.  NASA said the launch
will be delayed at least 7 to 10 days while an assessment
of the problem is made.