Fleet games I can think of.....
-One Page Rules: War Fleets
-Void Admiral
-Full Thrust
-Armada (But I see that as more SW fleet scale skirmish)
-Battlefleet Gothic (Not a great fit IMHO)
-A Billion Suns (Not a great fit IMHO)
-Firestorm Armada
- Jovian Wars (Not a great fit IMHO)
- There is a space-based Battletech game that is escaping me
- A Sky Full of Ships (?)
- Starfleet Battles (No, just NO!)
Space wargaming is really ripe for something to really hit home. However, it does pose its own unique challenges.
I would also consider looking at some Historical Naval Games with some bodged together rules. Anything WWII Naval based can probably be ported over.
- Pacific Command
- Victory at Sea
There are probably a ton of others in this space, but my memory is only so strong......