TRIPOD!!
I've never been to a shuttle launch before, so I don't have any direct experience with it.
It's going to be at night? To me, a long exposure (tripod, of course) with a wide enough lens to capture it all (in portrait orientation) would be pretty cool.
I would probably do that, and with another body with a longer lens try to get some closer, more detailed shots. That might be pretty hard to do if it's going to be dark though.