Laser-bounce radiation-pressuproblem

>> The laser stays on the ground and is bounced from focusing mirrors in
> GEO.
>
> How does that radiation-pressure affect the orbits of the mirrors?
> http://en.wikipedia.org/wiki/Radiation_pressure
>
> "Radiation pressure is the pressure exerted upon any surface exposed to electromagnetic radiation. If absorbed, the pressure is the power flux density divided by the speed of light. If the radiation is totally reflected, the radiation pressure is doubled."

Do you fear numbers? The next sentence reads: "For example, the
radiation of the Sun at the Earth has a power flux density of 1,370
W/m2, so the radiation pressure is 4.6 Pa (absorbed) . . . ."

9.2uP/1.37kW/m^2 is a force of 6.7 uN/kW. 5MW is 5000kW so the
radiation force on a mirror would be 0.033 N.

The force is directed radially (close enough). If you want to be
useful, check my calculations that a 5t bounce mirror would need to
orbit 0.4 km inside GEO to offset the radiation force.

Keith