Ok, so:
Space RTS: Homeworld, Homeworld: Cataclysm, and Homeworld 2 are by far my favorites. They are 3d movement in space, multiple game options, and a large variety of ships to choose from
As for a game like freelancer(one of my favorite space games), The closest I've found is Battlestar Gallactica Online.
It is Free 2 Play, 3d, browser based, the only downside is that you can't trade between systems. other than that most of the controls are the same as freelancer. good combat system, mine roids just like in freelancer.
Hope this helps
