Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: ELV launched boosters for shuttle payloads
Message-ID: <1990Jan30.191717.9035@utzoo.uucp>
Organization: U of Toronto Zoology
References: <1990Jan28.012650.19697@utzoo.uucp> <1990Jan29.233938.8795@tvcent.uucp>
Date: Tue, 30 Jan 90 19:17:17 GMT

In article <1990Jan29.233938.8795@tvcent.uucp> andrew@tvcent.UUCP (Andrew Cowie) writes:
>>The reason is economic: a low orbit maximizes payload with a given launcher.
>>HST is just too big for the boost up to Clarke (geostationary) orbit.
>
>[ I presume you mean STS in this case. ]

I'm not sure anything currently in inventory could put HST in Clarke orbit,
actually, although it might be possible if you were willing to wait a
couple of years for a Titan IV.  Regardless of booster, of course, doing
so means forgoing any plans to replace the instruments with second-generation
ones (which are already under development) and likewise forgoing any hope of
maintenance in the event of trouble.  These limitations would be less
troublesome if there were any plans for a successor to HST.

>... would it not be practical idea to launch a booster package
>(say a couple of Inertial Upper Stages stacked together) using an Expendable
>Launch Vehicle, (Titan IV) Then using the shuttle launch the main payload...
> mate it to the booster, and fire it?

In-orbit assembly is officially Not A Problem for the space station and
Far Too Difficult for anything else.  Damned if I know why.  It seems an
eminently sensible approach.

(Actually, I think I can guess part of the reason.  The upper stages are
not designed to sit in parking orbits for weeks at a time waiting for
their payloads.  Safety and manpower issues argue against trying to
launch two shuttles in fast sequence, and NASA still prefers to do its
launches in house [i.e. on the shuttle] rather than buying them from
somebody else who NASA doesn't control.  So in-orbit assembly is not
politically feasible even though there's nothing wrong with it from
a technical standpoint.)
-- 
1972: Saturn V #15 flight-ready|     Henry Spencer at U of Toronto Zoology
1990: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu