GURPS Space
Space Combat
I've modified two combat systems. One is changes I've made to the abstract combat system in GURPS Space. The other is a more fully developed hex-based combat system, building on the outline of the system in GURPS Vehicles/2e, and borrowing from GURPS Traveller.
NOTE: these are both for GURPS/3e. I'm hoping that when Space, Ultra-Tech, and Vehicles finally come out for GURPS/4e, that all of this will be obselete. If not, I will update it when I need to for that. Between now and then, I may write some stuff to go with the vehicles rules in the GURPS/4e basic set.