lightweight SSP and solar pressure

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.