From what I've seen, there is no real difference between ground and space as far as unit abilities and stats are concerned. If you look at ground buildings, for example, they have "space" position values so that the Rebel Speeders dont run into them. So, I figure you could adapt Chewie's capture ability to some special "Troop Boarding Vessel" a la Homeworld 2. I'd look now, but I'm at my college. x.x