Anders Sandberg wrote:
> While we all seem to be in space colonisation mode, what about
> re-using solar sail material?
> In my asteroid mining scheme, I send extra equipment using solar sails
> to the NEO mining base. So what do we do with them once at Orpheus; we
> can't have them litter the landscape.
It would be possible to keep them in a parking orbit by turning them
nearly edge on to the sun. Then the raw materials could be later used
for something else, if not a return trip to Earth.
> A solar sail would make a
> rather easily constructed solar oven when bent into a paraboloid and
> somehow anchored to the asteroid.
Or a reflector to direct sunlight down to the surface of the asteroid.
Sunlight being a scarce commodity out there, I could see where a
group of solar sails shining in the night sky would be a good thing
> They can also make a solar shade
> for the extracted fuel tanks during the trip back home to keep cooling
> of the hydrogen simple.
That sounds like the most reasonable use for them.
> (I guess they are not that useful for transporting propellant
> or other heavy products from the asteroid)?
No. The forces they provide are very small.
> Another use would be for the aerobraking part of the mission, where
> the fuel tanks are aerobraked for entry into LEO. The sails are
> definitely too flimsy to survive aerobraking in themselves, but I
> wonder if they might help provide some extra drag during the first
> pass. Any views on this?
I wouldnt think that would be a good use for them. An
aerobraking maneuver has all the *drag* it needs, simply
by plunging a little lower into the atmosphere. The limiting
factor there is the amount of heat dissipation the craft can
take. The little bit extra provided by (I assume you meant)
folding a sail over and over, then attaching to your ablative
shield would be too small to bother with perhaps. Theres
nothing stopping us from doing the calculations, however.
This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:59:42 MDT