Θ Games: Video_Games: Simulation: Flight: Orbiter

See also:

Site list:

Orbiter - A Free Space Flight Simulator A realistic 3D flight simulator that uses proper physics for the modelling of planetary motion, gravitational fields, free space, and atmospheric flight.
Project Alpha An ongoing project to simulate the International Space Station Alpha.
Orbiter Mars Includes concise tutorials that explain the procedures and the planning stage of interplanetary missions.
Orbital Mods An addon repository focused in the Russian space flight program. It also features a database of known bugs in the simulator.
Orbit Hangar Mods A general repository of contributions submitted by third party add-on developers.
Orbiter In Only One Page Offers links and files.