On Orbit is a spacecraft docking simulator and virtual space station construction kit. Manually guide the Soyuz capsule or the unmanned Progress cargo vessel to successful dockings with the International Space Station. Optionally dock the Space Shuttle with the ISS or the Apollo Command/Service module with the Lunar Module or Skylab.
You can trade the credits earned from each successful docking for space station modules. Build your own space station with life support, scientific, industrial, and even tourist modules. Populate your station with astronauts and see them working inside and outside the station, and view support craft arriving and departing.