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From: allen@mmm.UUCP (Kurt Allen)
Newsgroups: sci.space.shuttle
Subject: Re: Throttling the Challenger
Message-ID: <1473@mmm.UUCP>
Date: Mon, 19-Oct-87 10:14:29 EDT
Article-I.D.: mmm.1473
Posted: Mon Oct 19 10:14:29 1987
Date-Received: Wed, 21-Oct-87 00:14:04 EDT
References: <340@ablnc.ATT.COM>
Reply-To: allen@mmm.UUCP (Kurt Allen)
Organization: Software & Electronics Resource Center/3M
Lines: 22
Keywords: Challenger Throttle

In article <340@ablnc.ATT.COM> rcpilz@ablnc.ATT.COM (Robert C. Pilz) writes:
>
>I heard the commands to the
>crew to be at 105% throttle. They acknowledged that. Then they
>were told to go to 80% (or so). They acknowledged that. Then
>they were told (very quickly) to go back to 105%. At this point,
>the explosion happened.

The space shuttle engines were originally rated for less power, but
the max power rating was raised. I'm not sure if the increase in maximum
power was an engineering modification, or if the original restrictions were
relaxed, but the later flights of th shuttle typically used 100+ percent
power. I believe the maximum was 109 % of the originally rated maximum
power. Before the accident I had heard of plans to modify the engines
to handle even greater thrust.
So, to answer your question, the power up that occured was normal and
scheduled. It was not an emergency action in reaction to the SRB burnthrough.

-- 
	Kurt W. Allen
	3M Center
	ihnp4!mmm!allen