Huh, sounds a little like Lost in Space or Pitch Black (sorry, first two movies to come to mind for me.)

I'm in. Though I have some questions: is it an AU or real world universe? By which, I mean, are we considering technology (and thus space travel) to be as it is currently or more advanced? (To help me figure out a character concept of course.) I'm assuming current universe and technology/space travel because you said astronaut, but I wanna just double check.