im surprised no one has mentioned this indie title in process, with a demo avaliable right now
http://www.ceresthegame.com/extract from the IndieDB page: "This game would be defined as a RTS space simulator. Single player with multiplayer skirmish mode. The idea was at first to create a Homeworld clone, but it grew and became a blend of Homeworld, Elite and maybe a little of Sid Meiers Pirates. You control spaceships in a 3D enviroment. Point and click controls This game is about combat, ship management and modifications, construction, mining and exploration."
you can look it up here :
http://www.indiedb.com/games/ceres/newsmore info on the game:
basically the game starts in a far future where the solar system was ravaged by the opening of a wormhole gate, the gate was designed to connect to star systems and allow humanity to colonize other stars, but an accidental connection with a supernova caused a cataclysm that destroyed Earth and caused a failure in the machine, the gate since then has started to connect to different star systems and even universes, the stuff that has come from the gate has changed the solar system, adding strange gas formations and asteroid fields that are still a mistery.
as for Humanity, humans were already colonizing the other planets, the loss of Earth was just a setback and now humanity is divided in different factions related to their planets. there's a Terran Alliance, New Mars, the Ganymedians, the Titans, and others... artificial intelligences are present too, the most prominent being the "Hydra AI" which has make home around Jupiter and Saturn.
gameplay info:
-critical damage: ships get a critical damage percentage that reduces the effectivenes of their parts
-modular turrets: they're made of the weapon, the mount and accesories
-crew and AI get experience, you can have both humand and robotic crew
-AI can hack and invade enemy ship's computers in order to disable or control them
-player can improve skills via a perk system
-ship customization
-and other stuff typical of any space sim title......