Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Endeavour & GPS
Message-ID: <1991May1.162616.16919@zoo.toronto.edu>
Date: Wed, 1 May 1991 16:26:16 GMT
References: <4975@syma.sussex.ac.uk>
Organization: U of Toronto Zoology

In article <4975@syma.sussex.ac.uk> nickw@syma.sussex.ac.uk (Nick Watkins) writes:
>Endeavour carries a "navigation system used in the Gulf War". I take
>this to be GPS. Am I correct in this ?

It's about the only thing it could be.

>1) Why didn't previous shuttles carry it ?

The existing shuttle orbiters are all nearly ten years old, and the design
is even older.  Navstar, aka GPS, has become semi-operational only quite
recently.

>2) Do other spacecraft use GPS ? Was it part of ASAT designs, for
>example ?

I don't think any of the flown Asat designs used it.  I'm not immediately
aware of any current satellites using it, although there might be a few
doing it experimentally.  There is much interest in the idea.

>3) Is it precise enough to locate spacecraft *relative to each other* to
>order km. This would have been a real asset to ESA's cluster project...

It should be precise enough, but bear in mind that it won't work for
anything much beyond low orbit.
-- 
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  henry@zoo.toronto.edu  utzoo!henry