good start.
A good concept. The game would play better as a turn based strategy instead of real time. Judging from the title, I assume you intend to make a campaign for this in the future, that would help the game a great deal.
The absolute best thing you can do with this game is make it multiplayer (online). even without a campaign this would be really fun to play against other people online. If you were to do this, it would be best to keep it real time to keep the pace up.
One annoying thing though is the controls. It is difficult to de-select stars, and if you accidentally click a star to try and select it, all or half of the ships from your current selected stars go there and, worst of all, cant be recalled. I think this could be improved by having the player hold the ctrl or shift key while giving a command to keep the current stars selected and add any newly gained ones (possibly ctrl to keep the current, shift to also add new), when no key is held, all selections should be cleared after each action.