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From: David.Smith@cmu-cs-ius.arpa
Newsgroups: net.space
Subject: Orbital plane change
Message-ID: <516@sri-arpa.UUCP>
Date: Mon, 2-Apr-84 13:41:55 EST
Article-I.D.: sri-arpa.516
Posted: Mon Apr  2 13:41:55 1984
Date-Received: Mon, 9-Apr-84 05:33:56 EST
Lines: 26

My skepticism about using the space station for satellite repair was
admittedly from a chemical rocket mindset.  How old-fashioned of me not to
think of ion rockets.  (Previous discussions concluded that a solar sail is
not useful below about 1000 miles.)  Any low-thrust solution will take quite
a while, since to be effective it has to be applied at or near the orbit
crossovers.

How about the following, for low orbit plane changes.  This is based on an
article I read in (I think) Astronautics and Aeronautics not too many months
ago.

Move the perigee to the crossing node, and brake off enough speed to drop it
into the sensible (but still very thin) atmosphere.  Use wing lift normal
to the flight path to effect the plane change.  This may take several
passes.  Once the plane is sufficiently changed, fire at apogee to raise the
perigee.  Of course, the drag at perigee will drop the apogee, unless
thrusters fire during the maneuver.

As I recall, they expected lift/drag to be about 4.  So you get a major
plane change for 1/4 the propellant that would have been required for a
purely propulsive maneuver.  A boon whether you use chemical or electric
propulsion.

			David Smith

P.S.  Up with the winged space tug!