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From: grandi@noao.arizona.edu (Steve Grandi)
Newsgroups: sci.space.shuttle
Subject: Re: Throttling the Challenger
Message-ID: <648@noao.UUCP>
Date: Sat, 24-Oct-87 12:51:14 EST
Article-I.D.: noao.648
Posted: Sat Oct 24 12:51:14 1987
Date-Received: Mon, 26-Oct-87 02:13:07 EST
References: <187@scdpyr.UUCP> <8822@utzoo.UUCP>
Reply-To: grandi@noao.arizona.edu (Steve Grandi)
Organization: National Optical Astronomy Observatories, Tucson AZ
Lines: 17
Keywords: "Throttle up call"

In article <8822@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes:
>Actually, before Challenger there were plans to start using 109% for heavy
>payloads.  Those plans are now officially cancelled, although they could
>re-surface later if things go well and various minor engine improvements
>do indeed make the things more durable.

This "downscoping" of the shuttle thrust is causing major problems for
heavy payloads such as the Hubble Space Telescope.  Rumor hath it that the
current worst case projection (depending on the amount of solar activity
during the upcoming solar maximum which affects orbital drag) gives a
lifetime in orbit for HST after a 100% thrust launch of around 5 months!
It has always been planned to "reboost" HST during subsequent shuttle
missions, but no one quite thought it would have to be so soon!
-- 
Steve Grandi, National Optical Astronomy Observatories, Tucson AZ, 602-325-9228
UUCP: {arizona,decvax,hao,ihnp4}!noao!grandi  or  uunet!noao.arizona.edu!grandi 
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