@wkjonesactual space battles probably one of the hardest type of sci-fi fights to do unless you have a very active GM posting nearly every other post for various reasons, and/or having very good posts from the other rpers involved into it. either way the roleplay would be fairly open no matter which way you do it sense that's normally how sci-fi rps are unless your doing a Very strict story one.
For some people here I would suggest (for those wanting to do missions and crazy battles of various kinds) where they are part of/joining a Merc group that is stationed at the Space station that everyone is living at, this merc group probably has some sway on the higher ups of the station allowing them to get nearly anything they wish into the station. of course various players can create their own missions, Come up with their own factions and such (I would say in reason on the factions, trust me I've both seen and made insane groups before especially on the races). Everyone of course is at the station for their own reasons, some want to make a name for themselves in this merc group, some just want to live a peaceful life on the station, etc.... so the Center point for everyone is the same but what they do is up to them.
For GM I would give it to
@ladyanglaise sense they was the first person to take charge in actual working on an idea. If not then I can set up the forum, and general starting information for everyone.
One main thing is the GM would have to create a list of planets, space stations, Races, and factions. both some before the roleplay starts and as the roleplay grows and progresses. We could always have random 'Story Arcs' about some kind of faction is trying to take over or destroy everything and our merc group goes against them for money, glory, and other rewards.