dietz%USC-CSE%ECLA@sri-unix.UUCP (07/15/84)
Radiation pressure itself won't cause a satellite's to decay very fast, because accelerations on opposite sides of the orbit cancel out. The fuel is mainly to keep satellites at the correct longitude. When comsats have exceded their useful lives they are boosted to a somewhat larger orbit. Decay time from this orbit must be fairly long for this to work (how much bigger are these orbits?).
henry@utzoo.UUCP (Henry Spencer) (07/19/84)
> Radiation pressure itself won't cause a satellite's to decay very fast, > because accelerations on opposite sides of the orbit cancel out. The > fuel is mainly to keep satellites at the correct longitude. > > When comsats have exceded their useful lives they are boosted to a > somewhat larger orbit. Decay time from this orbit must be fairly long > for this to work (how much bigger are these orbits?). Not a lot bigger. Neither atmospheric decay nor radiation-pressure issues are very significant at 40000 km, where the Clarke ["geostationary"] Orbit is. As you point out, the staion-keeping fuel for a comsat is mostly to keep it at the right *place* in Clarke Orbit. A satellite boosted to a slightly higher orbit will be slightly higher for a long time, centuries at least I would think. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry