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From: wilkins@jarthur.Claremont.EDU (Mark Wilkins)
Newsgroups: sci.space,sci.space.shuttle,sci.astro
Subject: Re: Galileo Update
Keywords: Spin Separation
Message-ID: <2535@jarthur.Claremont.EDU>
Date: 20 Oct 89 19:30:27 GMT
References: <1939@jato.Jpl.Nasa.Gov> <2832@pikes.Colorado.EDU>
Reply-To: wilkins@jarthur.UUCP (Mark Wilkins)
Followup-To: sci.space
Distribution: usa
Organization: Harvey Mudd College, Claremont, CA
Lines: 25

In article <2832@pikes.Colorado.EDU> spinkert@pikes.Colorado.EDU (Scott Pinkerton) writes:
>In article <1939@jato.Jpl.Nasa.Gov> baalke@mars.jpl.nasa.gov (Ron Baalke) writes:

>>2.9 revolutions/second for the separation of the IUS from Galilio sooned
>>followed.
>
>Was this correctly printed ??  The IUS spun itself and the payload up to
>174 RPM prior to separation ??  That seems like an incredible controls
>problem to prevent the stack from spinning in a very wide "cone".  Also at
>actual separation, the CG will jump back some 30-40 feet maybe (don't know
>actual Galileo dimensions) - again sounds like one hell of a controls
>problem.  Was this meant to be 2.9 RPMinutes ??

   Sometime if you ever get the chance watch some of the footage of one of
those satellites with an IUS being launched.  When STS-26 went up many at
our school watched the TDRS deployment and the thing was rotating
about one or two times each second during the deployment from the cargo
bay.  Galileo is (I think) smaller than TDRS and I would not be surprised at
2.9 revolutions per second, especially after the IUS has carried the thing
some distance from the shuttle.

       -- Mark Wilkins