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Path: utzoo!henry
From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.space
Subject: Re: How long will a satellite stay in GEO?
Message-ID: <4110@utzoo.UUCP>
Date: Thu, 19-Jul-84 15:41:50 EDT
Article-I.D.: utzoo.4110
Posted: Thu Jul 19 15:41:50 1984
Date-Received: Thu, 19-Jul-84 15:41:50 EDT
References: <2016@sri-arpa.UUCP>
Organization: U of Toronto Zoology
Lines: 17

> 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