Sinfest

tinkeringIdiot · Joined: 13 Oct 2008 Posts: 1057

Japan is launching a $21bn initiative to put a 1GW power station into orbit that will beam power back to earth. NASA has a similar program going that isn't widely publicized.

WheelsOfConfusion · Joined: 09 Jul 2006 Posts: 11146 Location: Unknown Kaddath

This idea always seems to be looked at in fits and starts from the standpoint of official projects. The problem seems to always be the multiple launches of heavy lift vehicles required to get those panels in place, and then the actual assembly in orbit.
Oddly, the microwave transmission of power from the satellite to the ground station isn't such a technical problem, or even very hazardous: the microwaves generated in your kitchen's magic box are specifically picked because they have a certain wavelength than excites water molecules. A lot of the microwave end of the spectrum can travel right through clouds, pigeons, human flesh, burritos etc. without doing much of anything. You could actually build the receiving antenna grid right over a farm and not hurt the people, critters, or crops.
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tinkeringIdiot · Joined: 13 Oct 2008 Posts: 1057

I saw a lecture three or four years ago given by an engineer from ASME over the NASA version of this project. The proposed array is substantially larger than what the Japanese are working with, so the heavy-lift problem would be even greater. The solution? According to that speaker, NASA plans called for the panels and other bulky components to be built on the moon using materials mined from the lunar surface. Classic boundary condition switch: getting heavy objects into orbit is expensive...at Earth gravity.

WheelsOfConfusion · Joined: 09 Jul 2006 Posts: 11146 Location: Unknown Kaddath

But then you have to build the mine/refinery/factory on the moon too. Wouldn't a self-contained moon industry take even more effort and launches than the panel array?

tinkeringIdiot · Joined: 13 Oct 2008 Posts: 1057

That would depend on the expected service life of the array as well as the possibility of other uses for the moon base. Since the array would need periodic maintenance, the manufacturing base would have some predictable break-even point. Also, it would be really fricken sweet.

Yorick · Joined: 11 Jul 2006 Posts: 12066 Location: Mary's kesh

WheelsOfConfusion · Joined: 09 Jul 2006 Posts: 11146 Location: Unknown Kaddath

But it'll probably transmit to the ground with only about 80-85% efficiency, so you couldn't use it to power a time machine.

Unnamed? · Joined: 14 Apr 2007 Posts: 224

mouse · Joined: 10 Jul 2006 Posts: 15474 Location: under the bed

nono - make small, efficient family cars, then send the people up there to use them.
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