Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!cs.utexas.edu!uunet!microsoft!bobal
From: bobal@microsoft.UUCP (Bob Allison)
Newsgroups: sci.space.shuttle
Subject: Re: LDEF
Message-ID: <8739@microsoft.UUCP>
Date: 9 Nov 89 21:14:25 GMT
References: <3115@jhunix.HCF.JHU.EDU> <1989Nov1.024354.6148@utzoo.uucp> <8635@microsoft.UUCP> <14861@bfmny0.UU.NET>
Reply-To: bobal@microsoft.UUCP (Bob Allison)
Organization: Microsoft Corp., Redmond WA
Lines: 31

In article <14861@bfmny0.UU.NET> tneff@bfmny0.UU.NET (Tom Neff) writes:
>Bob Allison reminds us Solar Max will soon join Skylab and says:
>>That's one defect with designing a satellite which must be serviced by the 
>>shuttle at regular intervals (much less if we ever had a dozen up at once;
>>so far the plans only include HST and the space station as far as I know).
>
>There is a useful distinction between building a satellite that must be
>SERVICED by the shuttle (boards replaced, film collected, whatever) and
>one that must actually be REBOOSTED by it.  The former is merely
>questionable, the latter is downright dangerous.
>

Well, I did say "must be serviced by the shuttle at regular intervals", not
"can be serviced if necessary".  If it can be reached by the shuttle and
"must be serviced", then that service is going to include fuel.

Anyway, what is the estimated time between "fill-ups" for HST?  Hopefully, 
it is longer than the interval between the launch before Challenger and the 
launch afterwards (which is the only data point we've got for shuttles, 
although presumably next time the delay will be less).  And I do mean "when" 
and not "if".

In regards to how fast LDEF is deteriorating, I don't know, but the article
said Solar Max was dropping a mile a day.

That article in SciAm about Space Shuttle glow was pretty interesting: yet
another reason we don't want to be in quite-that-low-earth-orbit.  Looks 
like they've incorporated some changes into HST for it, though.

Bob Allison
uunet!microsoft!bobal