[extropy-chat] SKYHOOK: Check this out...

[Mike Lorrey]

http://exploration.nasa.gov/documents/reports/cer_midterm/Andrews.pdf

Given my recent reticence toward skyhooks anchored to earth as
monopolistic competition destroying devices that also eliminate use of
satellites (other than those in the skyhooks own orbit), I came across
a concept put out by Andrews Space in Seattle. Check out page 52 of the
above pdf. Its a skyhook that ends in LEO and travels up through L1 to
anchor on the moon.

Sounds like a great idea. One elevator all the way would require a
station in LEO traveling retrograde (it's at LEO altitude but only
circles the earth once every four weeks) at a velocity of under 1,000
mph. Called "Down Below Station", this station would be VERY EASY for
suborbital tourist rockets to reach without having to attain orbital
velocity. ANY ROCKET. This would be very good for building a robust and
competetive worldwide launch industry. This would also allow such
suborbital rockets to deliver people and packages worldwide, along the
moons orbital plane, in an hour, letting the moon's momentum do the
work (and our draining it will have the added bonus of helping to slow
down the rate the moon is receding from earth).

However, it would be very bad for all geosynchronous satellites. The
satellite television market would hate it.

A better solution is instead of one skyhook, build two: one with a
center of gravity in GEO which ends in LEO, say at about 250 miles
altitude (you could build multiple competing GEO skyhooks to LEO
eventually). This would make it even more affordable for suborbital
tourist rockets, since they just have to shoot straight up and peak out
at 250 miles at the station.

It eliminates the point to point earth travel option, but keeps the GEO
satellite infrastructure alive. The Suborbital rockets could also
theoretically refuel at the station to boost into a true orbit or
trajectory to any point on the planet.

The GEO skyhook would also sling payloads from its far end to reach the
upper end of the L1 skyhook, which would be anchored on the moon, pass
through the L1 point, and extend out another 60,000 km beyond the L1
point to the transfer station. 

Theoretically speaking, a suborbital rocket could boost up to DownBelow
Station, latch on to a tram on the Earth Skyhook, ride that up to GEO,
then ride it out to the far end, picking up several thousand kph along
the way, which will boost it out to reach the L1 elevator transfer
station. The passengers can then disembark and ride the elevator to the
lunar surface, or bring their rocket down with them. There would likely
be a large space marina built up over time at the Transfer Station,
which could operate off of berth rentals.



Mike Lorrey
Vice-Chair, 2nd District, Libertarian Party of NH
Founder, Constitution Park Foundation:
http://constitutionpark.blogspot.com
Personal/political blog: http://intlib.blogspot.com

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