Hi Lois,
This has some definite potential for a cool horror comedy IMO... You're probably just shooting for sci-fi horror, but for some reason I can't get the thought of Marvin from The Hitch Hikers Guide going homocidal out of my head : /
The issue with it, for me, is that it gives the impression that the main action is a chase... If it was contained in an area it would be a lot scarier. I'm no Blake Snyder zealot, but his take on genre is masterful. He breaks horror down into what he calls Monster In The House; the hero et'al must be in a place from which there is no escape... Even in horror flicks that take place outdoors, or in your case outer space, there are lots of examples where this is the case: Alien, The Blair Wich Project, Jaws, 2001 A Space Odessy...even Spielberg's early Duel... If they escaped the prison colony and crashed on a moon where there was some kind of deserted base etc etc etc.... But that would just be my spin.
Regardless, I see potential ... The hook is killer. Best of luck.