Orbiter Space Flight Simulator: Do You Have The Right Stuff?
By James Grahame
Martin Schweiger's Orbiter lets you try your hand at launching a space vehicle, although you should expect your first attempts to end in disaster. In fact, the FAQ includes questions like, "Why can't get into orbit?" The current version includes the TransX module to set up interplanetary routes, should you wish to try your hand at reaching Mars.
"Launch the Space Shuttle from Kennedy
Space Center to deploy a satellite, rendezvous with the International Space
Station or take the futuristic
Delta-glider for a tour through the solar system - the choice is yours.
The emphasis is firmly on realism, and the learning curve can be steep. Be prepared to invest some time and effort to brush up on your orbital mechanics background. Good starting points are JPL's Basics of Space Flight, and R. Braeunig's Rocket & Space Technology."