Thanks Robert That is just what I was wondering about. If the Moon or Sun tend to raise the orbits at that distance. I guess that anyone who follows the regular orbit adjustments for the active satellites might know if they are usually raised or lowered. That may be an over-simplification. Dale > -----Original Message----- > From: seesat-l-bounces+direland=drdale.com@satobs.org > [mailto:seesat-l-bounces+direland=drdale.com@satobs.org] On > Behalf Of Robert Fenske Jr > Sent: Wednesday, December 07, 2011 3:02 PM > To: seesat-l@satobs.org > Subject: RE: Goes 11 retired from service > > > The geosynchronous orbits are high enough that atmospheric > drag isn't a factor. > Only the lunar and solar perturbations are and they must > simply be not enough to move a satellite into the operation > orbit range. Or perhaps at that distance the perturbations > have a tendency to move the satellite even further away from > the Earth. > > I don't know why a higher orbit is chosen vs a lower one. > Since the manuevers are done at the end of life -- when there > is little fuel remaining -- often it is chancy whether the > push to the graveyard orbit can be done. It may be that a > push to a high orbit takes less energy and so is more likely > to succeed. > > Robert Fenske, Jr > > On Wed, 7 Dec 2011, Dale Ireland wrote: > > > Why is the "graveyard" 135 miles higher than the active > satellites? If > > the satellite becomes totally unoperational won't it > eventually drop, > > possibly uncontrolled, back down through the geo belt? Why wouldn't > > they make the graveyard 135 miles lower than the belt rather than > > higher? Are there other forces involved? > > Dale > _______________________________________________ > Seesat-l mailing list > http://mailman.satobs.org/mailman/listinfo/seesat-l > _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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