So, I've been 'elected' (via the not-it finger-on-nose method) to be the first of the rotating GMs for our Deathwatch group, having just completed Final Sanction/Extraction. As I'm the second most experienced GM of the five of us, I'm writing my own material and saving the prepublished stuff for the less practiced people when their turn comes around. Now to the meat.
My scenario seed is effectively as such: A space hulk has emerged in a system bordering the Realm of Ultramar, out of which the Ultramarines have detected the distress beacon of a Ultramar Navy strike cruiser that disappeared while on patrol a couple millennia ago. They promptly sent to the Deathwatch requesting a Kill Team to aid them as they locate the cruiser's wreck - of particular value because its records indicate a notable battle-brother was onboard when it vanished. (Our group contains two Ultras - hey, character hooks).
When they arrive at the planetoid-sized hulk, the first problem is pinpointing the distress beacon's location within it, which will require triangulation. They'll need to plant tracking beacons at three specific locations - one on the exterior, the other two just inside it. Later on, as they venture into the depths of the hulk, they'll meet genestealers and demons, but right now I'm at a loss for figuring out what sort of encounters/monsters I can use for the exterior portion of the session. I'd rather not open up with stealers this early (using health-boosted DH stealers instead of the Landsholme ones, just to mess with their heads), but I can't think of anything else that can survive open vacumn. Any suggestions?