Allows you to create your own star system with various celestial bodies, including planets and moons, and run a simulation. The program uses the actual bitmaps (if known and available) of the planets in our system, enabling you to modify nearly anything about them: mass, coordinates, velocity, inclination, rotation, and so on. You can also create an AVI recording of your simulation, launch probes from various planets, and attempt to land on other planets as well as orbit them.