> you can't use these lasers to slow down the probe
You can, but you need a couple of solar sails. You beam the laser at the sails to accelerate, then at the halfway point one of the sails detaches and becomes a reflector, which lights up the now flipped probe and remaining sail to decelerate them.
You can, but you need a couple of solar sails. You beam the laser at the sails to accelerate, then at the halfway point one of the sails detaches and becomes a reflector, which lights up the now flipped probe and remaining sail to decelerate them.