Just a reminder, an SSP doesn't get as much thrust as a solar sail
because a solar sail reflects photons and an SSP absorbs them. Thus,
the total photon-force is roughly half. Roughly because absorption
isn't perfect and the energy that isn't turned into energy is
reradiated -- in my design out the back which counter-acts the thrust
of the Sun's photons.

Also, the beam generates significant thrust relative to solar
pressure. It's direction is always anti-Earthward.

Thus, my simple sim is enough to suggest this isn't a hard problem to
solve, but when time comes to really build one these things a more
detailed and accurate analysis is necessary. Operational procedures
will need to be developed to keep the sat within range of the ground
receiver.

However, right now we have much, much bigger problems to solve, like
launch.

Am 05.02.2012 18:30, schrieb Al Globus:
> Just a reminder, an SSP doesn't get as much thrust as a solar sail
> because a solar sail reflects photons and an SSP absorbs them. Thus,
> the total photon-force is roughly half. Roughly because absorption
> isn't perfect and the energy that isn't turned into energy is
> reradiated -- in my design out the back which counter-acts the thrust
> of the Sun's photons.

Another add is, that a solar sail spacecraft is also not perfectly
reflective, and it degrades when time passes by, loosing some of its
reflectivity.

Best wishes

Frank