Chino reported :
" Orbiter is a amazing free 3D Space Simulator written by Dr. Martin Schweiger, Ph.D. Orbiter contains accurate math and orbital physics, and has an extensive community support base.
I stumbled on an incredible piece of freeware by Dr. Martin Schweiger, Ph.D. - Orbiter.
It's an amazing spaceflight simulator with very accurate physics and amazing expandability. I've just installed it (with optional but recommended 3d party sound pack) and so far have only run a couple of the demos, but the Atlantis Space Shuttle launch demo alone is worth the effort (the price is free! but install and activate the sound pack first). This has great obsession potential.
Amazing that it's freeware, as it seems to be
Microsoft Flight Simulator 2004 level in quality, depth, accurate physics, and expandability. It's really a flight sim too as the fictional spacecraft have atmospheric flight capability and you can land them (powered) at KSC or even land the Shuttle (unpowered!). New 2005 version as of Jan/Feb with a lot of new goodies.
"Go Play in Space" (Second Edition) by Bruce Irving.
Fun with Martin Schweiger's Orbiter Space Flight Simulator. This Introductory Tutorial manual is a colorful picture book about humans going to Mars, how they might realistically go about this, and where this might lead in the future.