I don't see why it can't be used in space either.
Before I looked, I wondered if some of the projectiles were set up with control surfaces which would not work in vacuum, but didn't find any. However, the rangefinder does seem to use atmospheric physics in order to add more precision to the strike; but even that can be turned off in favour of the suit's AIES. As for insane ranges, one really just needs to compensate for the local gravity environment based on nearby collections of mass (asteroids, planets, stars...), otherwise it will just keep going until it hits something.