FREE, er, SCREW MARS... How About Solar Power Satellites After Going To The Moon?

Because space power systems are ridiculously impractical and require a truly delusional flight rate to complete.

Brett

Because its a Really Bad idea. Launch cost from earth to GEO is about $40-$80K per pound. Right now, launch cost from the Moon to GEO is infinite, and I don't expect the price to come down soon. Solar cells are about 25% efficient at converting sunlight into electricity at the beginning of life, degrade over time, and aren't weightless. The ISS photovoltaic power system, for example, weighs 70 tons for about 100 kW of generation. This weight is mostly structure, wiring, power conditioning equipment, solar cell cover glass, etc. - not the solar cells themselves. Sending the ISS power system to GEO would cost you at least $56K per Watt (!) of generating capacity based on the launch cost alone, let alone the cost of design and fabrication of the hardware. At this rate you would be ahead if you just paid $560M (yes, $560,000,000) for a 10 kW portable generator on the ground. But the power is now 22,000 miles away - it still has to be converted and transmitted back to Earth (via microwaves? laser?), collected, and converted back into electricity on Earth. Laser power conversion efficiencies are abysmal. Some uninformed people already get upset about exposure to RF energy from radar, TV and radio transmitters - they'll have a field day with this one. We can't get to GEO with the shuttle so you'd better not have anything break over the expected 20 year life, either.

I have a Honda generator for sale if you are interested. Only $100M.

Brad Hitch

sorry if previously posted.

Why hang more junk in space for earth-to-lunar transports to avoid? easier to just put the solar collectors on the moon and ship it to earth. less tools lost, less risk to repairmen, and no need ot match orbits.

plus it is much easier to work on gravity than zero-g (even if one sixth, maybe better)

But you'll *still* need relay satellites in GEO, to get the power to where you want it. As long as you're going to have satellites in place, why bother with a relay - put the generator on the GEO satellite and be done with it. ;-)