[Server-sky] Brainfart of the month - Server Sky GTO Hitchhiker Test

[Keith Lofstrom]

Hey folks!

I've been busy preparing a paper for the SSPS / Wireless
Power workshop in September - lots of kvetching, I seem to
be flouting the One True Way for SSPS.  Oh well.  If they
don't accept the paper, then I'll share it here, and you
can share it with your friends as "the paper the Space Solar
Power Institute doesn't want you to see".  Space samizdat!


On a happy note, I think I figured out how to do the first 
server sky thinsat maneuvering tests.  Atmospheric drag is way
too high to do a good test in LEO.  However, if I can hitch a
20 gram ride on a GTO transfer stage, and signal it to ignite
a deployment charge, I will get about 50 orbits until the
thinsat orbit decays.  Good enough for a first article test.

Next, I can build a more ambitious test that deploys a 92
thinsat array, also on a GTO stage.  The carrier platform
can be powered by 4 Estes model rocket engines - the first
to raise perigee by 300 kilometers with a 30 m/s burn of
one toy engine, then dispense the thinsats over the next
11 hour orbit.  At the next apogee, the three other engines
on the empty carrier fire to drop perigee to reentry.  Two
toy engines are enough to bring down the loaded carrier.

If the thinsats can maneuver to be edge-on at perigee,
they will lose about 2 m/s of velocity during each pass;
if a thinsat fails to maneuver, it will tumble and
lose about 20 m/s.   After losing 2200 meters per second,
the orbit circularizes in the high drag region and the
thinsats decay and reenter a few hours later.  All told,
about 500 orbits and 200 days of testing, cut to a day
if deployment doesn't happen, and a month for thinsats
that fail to maneuver.

Still pretty handwavy - watch this page for updates:

http://server-sky.com/HitchhikerTest
 
Keith


-- 
Keith Lofstrom          keithl at keithl.com