I heard from a fellow GM that sharing your game ideas and getting feedback from someone who wont be in the game is a great way to work out flaws and such. I believe that this thread should be a place for just that. So without further ado, here is my game plan.
Mind you, this is for a bunch of people new to the universe (excluding the RT himself).
Super high security prison world, prisoners somehow got a radio to call for help. Claim to be workers settling a new planet. Send PC's deep into woods searching for "lost workers". Ambush PC's who learn something is "up". Figure out that the "workers" are criminal masterminds trying to get off-world. Tractor beam or some such device holds the PCs on planet unless an override code is given (have a stowaway onboard for just such an occasion). Have an underground band of PoW's who are willing to help the PCs (including Xenos)(If PCs play their cards right, allow for a Tau Commander to join them giving them access to some Tau tech).
After that its just minor bits to keep them wanting to play again (*cough*necron ship*cough*)