Ever felt like escaping earth's gravity? Wonder how it feels like doing an intercept mission with the ISS? Do you suspect there there are alien life forms on Mars? Deep down in Europa?
THIS IS FOR YOU!
Disclaimer: This software is provided without any warranty. Any loss of productivity, collapse of professional life, or suffocation in Low Earth Orbit, is the sole responsability of the user.
http://orbit.medphys.ucl.ac.uk/
:P