Something fun that's free...

[unclejimbo]

Name of program is Orbiter 2006. It is a very good spaceflight simulator in which you can carry out a mission to the ISS with the shuttle or a delta winged vehicle. (Use the delta wing first. Flying rockets is harder than it seems.)

http://orbit.medphys.ucl.ac.uk/orbit.html

All you need to invest is time. The graphics are top notch and you don't need an uber machine to run it. (600 MHz recommended.)

You also can download the Apollo mission at this website.

http://www.acsoft.ch/AMSO/amso.html



Have fun!