What does "controlled by the SM" mean?
Does that mean that if I'm playing the game I will have to play any opponents too?
Although Aurora is now a very different game than 3rdR Starfire, that game had a lot of influence in the early design of Aurora. Starfire was designed to be played with several players and a spacemaster with the spacemaster setting up the campaign and playing all non-player races; although many people including myself would play solo campaigns, playing all the races in order to create a universe history that they could write about. The Rigellian Diary is an example of that type of campaign.
Aurora (for the moment) follows the same pattern. If non-player races are created, the spacemaster (or solo player) will play those races. This is a lot easier than it sounds because when you log in as different races you get their view of the universe, based on the information gathered from their sensors and explorations, which makes it very easy to play from their perspective. Using themes and your own imagaination, races will have different "personalities" that will change and develop as they react to events, which you can use to guide your actions.
Longer term, I will be adding more and more intelligence to non-player races so that you can devote less and less time to them, or eventually leave them to play themselves. However, the precursors from the earlier versions that return in v2.6 will be played entirely by a computer player. Unlike earlier versions, they use exactly the same rules as players and they use normal ships, not simplified versions. In v2.6, they can also survey and explore. I will be adding additional capabilities with each version until precursors become fully functional races, but that will take some time.
Steve