stinky wizzleteats writes "Ever wondered why a space flight simulator never really got off the ground in the PC simulation scene? The answer is that it needed to be free. Dr. Martin Schweiger started the ball rolling a few years ago with Orbiter, a freeware Win32 DirectX based space flight simulator, in which you can fly orbital rendezvous, lunar landing, and even interplanetary missions. The current version has excellent graphics, including atmospheric descent and re-entry effects. There's also a burgeoning community of add-on developers, creating everything from sound add-ons and interplanetary navigation aids to complete working Apollo/Saturn 5 spacecraft. Virtual space agencies have even sprung up, using Roger Wilco and remote telemetry software (virtual mission control) to do Orbiter missions online. You can find the basic Orbiter files at Avsim or Sourceforge."