Orbiter is a free space simulator, and it is also one of the most realistic. This isnít one of those space arcade games where you zoom around and shoot aliens. This simulator will show what itís like to really be in space. Created by Martin Schweiger, it employs real life physics. The game takes a while to master, but itís definitely worth it. Orbiter allows you to recreate classic space flights via its addon packages like Vostok, Apollo, Gemini, Mercury and more. it even has the Space Shuttle which can be launched from Kennedy Space Center. You will also see the ISS (International Sapce Station).