You can get Free 3D spaceships from NASA here: click
There are all kinds of things available - 3D model of the Space Shuttle, Apollo Lunar Lander, the International Space Station, Skylab and many more. (All man made stuff, mostly US, no Area 51 or alien ufo's though :p) They are in .3ds format and come with lowish-res textures. I had to tweak the textures and model bit, but they seem to work fine, as you can see in the quick rendering I did above. Not bad for a free model.
There are also some planet and space textures available, like this texture map of Mars
and this map of a control panel from the Space Shuttle flight deck
A handy resource if you need to make some spacey stuff!