Here is an example spaceship.
Imperial Federation Fighter
Battle Skill: Equal to Skill + Piloting skill of pilot.
Movement: 10 (of course, the scale in space will be different, so this is not equivalent to 10 squares on a land mass battle. If a fighter was taking part in one of those, it could probably move wherever it wanted to in a turn).
Battle Stamina: 6
Shields: Battle Stamina: 3
Imperial Federation starship
Battle Skill: Equal to skill of command unit + Piloting skill (piloting will be a mass battle unit skill. The command unit will probably be made up of the bridge officers - captain, first officer, helmsman, tactical officer)
Battle Stamina: 20
Shields: Battle Stamina: 10
Weapon: Torpedo (limited number)
Of course, making scifi things compatible with fantasy counterparts isn't as difficult as it appears to be. There is, after all, an upper limit to what weapons can do (in the Star Trek episode Balance of Terror, a nuke did a lot of damage to the Enterprise) and if there are weapons that can vaporise whole units of soldiers with no save, they can be limiting in other ways, like needing x rounds to charge, or dealing damage to the user.