another alternative to building stations.

Energy delivered per square meter of cross-section is higher for photons,
but the magsail's magnetic field can cover a larger cross-sectional area for
a given mass of equipment. Magsails only become cost-effective if one can
make a superconducting wire 150 KM long, that can operate in direct
sunlight. As superconductor technology is not there yet, the lightsail is a
more effective choice at the moment. An alternative design, that uses a
cloud of charged gas instead of a wire loop, has been proposed as well, and
it seems promising.

Your idea of using a solar-powered satellite to deliver power via a laser
has come up more than once, and seems to be an elegant solution. The only
issue is the total reliance on targeting accuracy, and therefore timing.
Aiming a laser at something that is potentially light-hours away is a dicey
proposition, especially when that object accelerates.

On 5/23/06, Robert wrote: