This one looks a peach:
http://farcolony.sourceforge.net/
http://sourceforge.net/projects/farcolony/
"FAR Colony (First Autonomous Remote Colony) is a game of exploration and space colonization being held in the 23th century. The game will include management and strategy in more or less long term, where use of military force is not an required way."
Screenshot:
http://sourceforge.net/dbimage.php?id=258588