Plane change using aerobraking

Hi,

In one of those moments of conceptual flux, I wondered if it would be
feasible, using today's existing materials, to developp a
zero-propellant orbital plane change capable satellite. (Emphasis on
the word -propellant-, not -energy- ;-P)

Considering that orbital plane change requires so much energy, in
fact, in many cases more energy than relaunching the thing from the
ground up again, I was considering combining two methods to achive a
plane change with zero propellant usage.

Consider a satellite with an electrodynamic tether and appropriate
structural stiffness and materials to resist Very LEO passages thru
the upper fringes of the atmosphere. Using it's solar panels as flaps,
a la Mars Global Surveyor, it would aerobrake with a profile such that
the resulting vector would be as perpendicular as possible to the
orbit in a normal or antinormal fashion, changing the inclination a
few tenths of degrees at a time, every 90 minutes...

At apogee, the sat deploys an electromagnetic tether, and using power
from it's solar panel, induces propulsion to raise the perigee back to
the optimal altitude.

My questions are, how long would a tether need to be to provide
substantial propulsive capability, for "average" solar panel output.
And what would be the optimal perigee, balancing the thermal and drag
issue along with a reasonable plane change capability. At what point
does one need to consider thermal cycling issues and integrating a TPS
into the design?

The drag created by tethers can also be used for braking/ deorbiting... in
fact, I seem to recall Boeing or TRW looking into making them standard
equipment for de-orbiting without relying on chemical motors or fuel.

On 24 Jul 2004 14:55:03 -0700
(Remy Villeneuve) wrote:

Using it's solar panels as flaps,
a la Mars Global Surveyor, it would aerobrake with a profile such that
the resulting vector would be as perpendicular as possible to the
orbit in a normal or antinormal fashion, changing the inclination a
few tenths of degrees at a time, every 90 minutes...

One thing to note is that at hypersonic speeds it is impossible to achieve a high lift/drag ratio. What this means is that much of the impulse experienced by the aerobraking spacecraft will be drag, with a small amount of lift. Because of this I think it will run out of orbital velocity before it gets much of a change in orbital plane.
--
Michael Smith
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