well, as most of the movies use the FX field, nowadays:
you render something with a black, green or blue backround, with or without a mask, and then import it and use the mask or the background color to cut that part out and lay it against a background.
so, in the case you have a scene where the ships exits a dock, or a starbase, and goes past the camera, the dock or starbase will be a fixed picture, and the ship a masked movie. instead of having a 300MB movie with ship, background and starfield, you have a 12MB movie of the ship, a 20k picture and a starfield. then, the output movie might be 200MB uncompressed and around 70/80 with .avi or .divx codec.
this doesn't apply if you have a camera pan with ship and dock all-in-one. saw that pic with the sovvy in dock from the back in my thread? that's a part of a panning. the rest is a montage.
also, you can skip rendering effects in Max, and add them later, like flares, explosions, engine glows, motion blur, etc.
I think you can download a demo of after effects from the Adobe site, it won't be fully functional, but you'll have the basic composition tools. you'll have to ballance what you render in max and what you merge in post-production
I suggest you render the shots a little longer than what you planned, so you have a margin to place the shot earlier or later in the movie, in case you want to match a sound track.
that's why many movies have deleted scenes lol