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Path: utzoo!henry
From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.space
Subject: Re: Has Shuttle disaster killed Galileo?
Message-ID: <6348@utzoo.UUCP>
Date: Mon, 3-Feb-86 17:34:18 EST
Article-I.D.: utzoo.6348
Posted: Mon Feb  3 17:34:18 1986
Date-Received: Mon, 3-Feb-86 17:34:18 EST
References: <895@h-sc1.UUCP>
Organization: U of Toronto Zoology
Lines: 36

> I understand that the Galileo probe has a two-week launch window in March.

I think it's in June, actually.

> The next window will be in two years. 

There is a launch window for Jupiter about once a year, since Jupiter
orbits fairly slowly and Earth's own motion dominates the window timing,
but they're not all equally good.  In particular, the arrival velocity
varies some, and low arrival velocity is important for missions like
Galileo that are doing more than just a flyby.  It may well be that the
1987 window is a poor one.

> Since it is very unlikely that the
> Shuttle program will be reinstated by then,
> does this mean that Galileo is dead?

No, but delayed almost certainly.  It would be a minor miracle to get the
Ulysses and Galileo launches off on time in June, even if the Challenger
problem is diagnosed and fixed quickly.  (Ulysses too wants to go into
the Jupiter launch window.)  The schedule was looking tight as it was,
with some problems in getting the Centaur G-Prime upper stage ready for
the shuttle cargo bay.

It's not as if Galileo hasn't been delayed plenty already... :-<

> Is there any way that this probe could be launched by other rockets in time?

I doubt it very much.  It's a big, heavy probe, with a high velocity needed;
Shuttle plus Centaur-G-Prime is the heaviest booster the US has right now.
The few heavy expendables the US has are all earmarked for other things, and
I'm not sure Galileo would fit under their payload shrouds anyway -- it was
really designed for Shuttle launch.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry