Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Hubble Space Telescope
Message-ID: <1989Dec14.171850.643@utzoo.uucp>
Organization: U of Toronto Zoology
References: <14089@grebyn.com> <1254@ispi.UUCP> <1387@argus.UUCP>
Date: Thu, 14 Dec 89 17:18:50 GMT

In article <1387@argus.UUCP> ken@argus.UUCP (Kenneth Ng) writes:
>I'm just curious, does anyone know how HST will be lifted into a
>higher orbit?

The nominal plan is to have the Orbital Maneuvering Vehicle grab on
and push.  What happens if HST needs reboost before the OMV is ready
to fly, I'm not sure.

>Will it be put into the shuttle and the shuttle
>takes it higher?

This is theoretically possible -- HST's solar arrays are designed to
re-fold (well, re-roll actually), unlike those of most satellites --
but it would be wasteful.  The shuttle orbiter weighs lots more than
HST, and one would prefer not to haul all that extra weight along.

>... Perhaps the shuttle will
>refuel it and the HST station keeping rockets will raise it?

HST has no propulsion system of its own.  It uses momentum wheels for
attitude control and magnetotorquers (electromagnets interacting with
Earth's magnetic field) to desaturate the momentum wheels when needed.

>How about put the HST on a long tether and as the shuttle descends
>the HST will orbit faster until the cable is released and the HST
>is propelled into a higher orbit?  Am I making sense?

This would make some sense, and similar ideas have been talked about in
other connections, but tether technology is still mostly on paper.
-- 
1755 EST, Dec 14, 1972:  human |     Henry Spencer at U of Toronto Zoology
exploration of space terminates| uunet!attcan!utzoo!henry henry@zoo.toronto.edu
