Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!haven!aplcen!aplcomm!stdb.jhuapl.edu!jwm
From: jwm@stdb.jhuapl.edu (Jim Meritt)
Newsgroups: sci.space.shuttle
Subject: Re: satellites and orbits
Message-ID: <2708@aplcomm.jhuapl.edu>
Date: 13 Dec 88 17:17:26 GMT
References: <13171@srcsip.UUCP>
Sender: news@aplcomm.jhuapl.edu
Reply-To: jwm@aplvax.UUCP (Jim Meritt)
Organization: JHU-Applied Physics Laboratory
Lines: 26

In article <13171@srcsip.UUCP> rogers@orion.UUCP (Brynn Rogers) writes:
}
}[lots of stuff about orbits and which satellite it could be deleted]
}
}From my limited knowledge about satellites I do know that a 
}very significant percentage of the satellites weight is fuel (hydrazine)
}for station keeping, orbit changes, ...
}
}In the TRDSS that got put in the wrong orbit (B? A?) the whole
}reason its lifetime went from ten years down to two is because it
}wasted 8 years of station keeping fuel to finish boosting it into the
}correct geosyncronous (sp?) (Clark orbit=Geosync?) orbit.
}  When that fuel is gone it will drift into crummy positions that
}won't be useful.

And therein lies the biggest problem with meterological satellites.
It takes gas to move those suckers to look at the right places.  When
they out of gas, there they sit.

Ask around about Goes.

BTW:  There are non-hydrazine (non propellant, in fact) methods of
maneuvering satellites, but they ain't (to my knowledge) fast.


Disclaimer:  "It's mine!  All mine!!!"   
					- D. Duck