Guest blogger Sam Dinkin has a couple pieces at The Space Review today--an interview with Dave Criswell, co-inventor of the Lunar Power System (Bob Waldron, who used to work for me at Rockwell, is the other co-inventor), and an assessment of the global implications for the development of such a system.

I have to confess to being an LPS skeptic, but DoE has wasted a lot more money on a lot less promising things. In any event, the key to making any of these things happen, whatever their technological feasibility level, remains the cost of access to space.

Agreed.

Oh, and they should consider moving from microwaves to millimeter waves (gyrotrons) as the energy can be absorbed at much higher intensity with smaller facilities at high altitude. Stray radiation won't get through to the lower populated altitudes due to water vapour absorption - a desireable property for a number of reasons.

The one thing I've never figured out about LPS is how it's supposed to be the primary power supply with a two week night on the moon. Stored power on the moon to rebroadcast? Store power on Earth? Put it on a rotating fixture at the Lunar pole?

SPS has its problems--mostly the same ones as LPS--but at least you only get short midnight blackouts. How is LPS supposed to outcompete that?

I think that the assumption is that cell farms are emplaced all the way around the moon, and the power is carried from the far side to the transmitter on the near side.

I think the idea was to place the PV farms on the two limbs of the moon (as seen from Earth), so it isn't necessary to transmit power very far.

These kinds of megaengineering proposals are fun, but they aren't going to do much aside possibly from earning Criswell mention in future histories of space development.

On a smaller (maybe a few GW) scale, I wonder if it would be possible to put large particle beam weapons on the moon, for Earth surface bombardment? The idea would be to produce extremely energetic proton beams, have them hit the atmosphere to produce muons, which would cause lethal radiation on the ground and in buried bunkers. Very energetic particles don't have to be neutralized since they won't be deflected much by magnetic fields (and the impact point on Earth can be monitored to provide feedback, albeit with a time delay).

Paul D.

Better yet why not a mass accelerator and throw rocks downhill into the gravity well of the Earth. Lots of capability with a kinetic kill vehicle.

buffpilot: the peak power requirements for throwing rocks of useful size is much higher, and the rocks do not penetrate as far as very energetic muons would. Radiation can be delivered more quickly as well.

There are a lot cheaper to ship radiation than building a Lunar installation.

Sam: radiation capable of penetrating deeply into shielded installations? Not even the radiation from a nuclear blast will do that (and nuclear explosions are ruled out on treaty ground). Now, maybe this scheme would could as a WMD, in which case it's also prohibited by treaty, but maybe not.