Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site quest.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!stolaf!umn-cs!quest!dave
From: dave@quest.UUCP (David Messer)
Newsgroups: net.columbia
Subject: Re: orbiter assent attitude
Message-ID: <333@quest.UUCP>
Date: Sun, 9-Feb-86 04:35:53 EST
Article-I.D.: quest.333
Posted: Sun Feb  9 04:35:53 1986
Date-Received: Tue, 11-Feb-86 07:09:04 EST
References: <999@burl.UUCP>
Distribution: net
Organization: Quest Research Inc., Burnsville, MN
Lines: 21

> Can anyone explain why during assent the orbiter flies upside-down?
> I remember reading somewhere that it was necessary for the crew to
> see the earth's horizon during assent and that it is difficult to do
> that with a normal attitude because the tank and boosters would be 
> in the way.  With todays guidance control systems, it has been hard
> for me to buy that argument completely.  Does anyone know the true
> poop on this subject?

The shuttle does indeed fly upside down so the pilot can see the
horizon.  I think you are probably right about todays guidance
systems (if a system failure was so complete as to create a need
to 'eyeball it', I don't think it would matter), but American
manned spacecraft have always flown upside down for that reason.
I think the bottom line is that there is now reason to pick any
other attitude, so they might as well choose one that provides
some marginal safety advantage.
-- 

David Messer   UUCP:  ...ihnp4!quest!dave
                      ...ihnp4!encore!vaxine!spark!14!415!sysop
               FIDO:  14/415 (SYSOP)