Ool wrote:
"Hop David" wrote in message ...


What would it take to focus & reflect sunlight on a lunar colony from a
series of orbiting lunar satellites? I'm imagining something where one
satellite comes over the horizon, focuses light onto our moon base
(which is in the dark of course), then as it goes down, another
satellite comes up and takes over the job. (I'm assuming these
satellites have to be in a fairly low orbit since otherwise you wouldn't
be able to focus the light to sufficiently small spot.)


I'd vote for an sps satellite parked at the L1 point where they're
hoping to send the James Webb scope. That might be useful for colonists
during the long lunar night.



The JWST is going to be parked at the Solar L2 point, 1.5 million km
out from the Earth-Moon barycenter, not the Lunar L1.

Doh! What was I thinking. Yes, right you are.



But I agree that an solar power satellite in L1, where there is always
sunlight except during Lunar and Solar eclipses, makes the most sense.
It would beam down the energy as short-wavelength microwaves. (You
don't need to use the wavelenghts you'd use on Earth because there's
no atmosphere to penetrate, so the rectenna could be smaller.)


I've read a few chapters from the Lunar Base Handbook, and one project
estimate is that the solar panels needed for supplying an initial base
would weigh only a ridiculous 1t while the equipment needed to *store*
enough power for surviving the Lunar night would weigh about 45t.

So finding a spot that's perpetually in sunlight isn't such a bad
idea, be it a mountain on the south pole or L1...

Is there such a mountain?



--
Hop David
http://clowder.net/hop/index.html