Path: utzoo!attcan!uunet!cs.utexas.edu!rice!eunomia!animal
From: animal@eunomia.rice.edu (Carl Rosene)
Newsgroups: sci.space.shuttle
Subject: Re: LDEF capture time change (Forwarded)
Summary: Low is High
Message-ID: <4238@brazos.Rice.edu>
Date: 13 Jan 90 20:49:24 GMT
References: <40214@ames.arc.nasa.gov> <2187@xyzzy.UUCP>
Sender: root@rice.edu
Reply-To: animal@eunomia.rice.edu (Carl Rosene)
Organization: Rice University, Houston
Lines: 29

In article <2187@xyzzy.UUCP> poirier@dg-rtp.dg.com (  Charles Poirier) writes:
>
The LDEF was more-or-less on the verge of
>falling out of the sky due to atmospheric friction.  The shuttle
>caught up to it by orbiting at a lower altitude.  My question is,
>how much lower?  How much drag did the shuttle experience by orbiting
>lower than LDEF?  And, were any special adjustments made to the
>shuttle's attitude or configuration to reduce drag in such a low orbit?
>

Lower and Higher are rather relative here. Fact is, the LDEF is(was)
at an altitude higher than typical shuttle missions. The LDEF was 
about 200 hundred miles or so up. 
The shuttle was in an orbit maybe 20 miles lower (I'm sure people
will be correcting this number). It is unnecessary for a shuttle
to go more than about 150 miles high for a typical satellite 
launch. So, there were no special precautions necessary to
reduce drag, since it was not any greater than an orbiter
experiences normally.

One moral is that the atmosphere does
not end suddenly. At one hundred or two hundred miles there is
little enough drag that you can get into an orbit. But, how 
long you stay there is another question. If you only 
plan to stay a week it doesn't matter much. A few months 
and it's time to get out your slide rule.

Carl Rosene
Rice University