Ride the ion train from the Moon to Earth

New Scientist ^ | 01/22/07 | Kelly Young

[KevinDavis]

Spacecraft could one day be propelled by ion beams shooting up from the Moon, according to a recent concept study.

Other spacecraft, such as Deep Space 1 and SMART-1, have flown with ion engines, which work by stripping electrons off gas atoms and accelerating the ions with an electric field. The ions create thrust as they are shot out of the engine.

The idea behind the new study is to rip out the engine and mount it on the ground, beaming ions up to the spacecraft. "This first look at the idea seems to indicate that it is, in principle, feasible," says Ian Brown, a retired physicist from Lawrence Berkeley National Laboratory in Berkeley, California, US and one of the study's authors.

An ion beam generator on the Moon could send spacecraft to nearby Earth-Moon Lagrange points – places in space where the gravity of the Earth and Moon are balanced – or perhaps to send lunar cargo to Earth.

The spacecraft would still have to take off using a chemical rocket, because the beam would not provide enough thrust to launch a heavy craft directly from the Moon. But with ion drive taking over after launch, the rocket could be relatively small.

[KevinDavis]

[Vaquero]

you could use a mass driver to lift off the moon. Linear electric motors using power provided by the same solar array or Nuke plant you would use for the ion drive could be used for the launch.....