3 ms·

Could it redirect the beam it recived from earth, back unto a probe behind itself in mid flight?

• SamReidHughes 10y ago
  Yes, with a giant mirror. And that's the best way to do it. But note that all lasers spread out in a cone -- they aren't a perfect column. The angle of this cone can only be made smaller by making very large optical equipment (I'd guess in the form of a large parabolic mirror collimating an earlier stage as best it can) which means far away probes only get a fraction of the energy Earth is sending. This also means the reflection only has a small portion of the initial light, and then the reflected beam spreads out with its own cone as well. So the deceleration stage is vastly longer than the acceleration stage.