I'm guessing I'm a bit too late to help here. What did you end up doing? For other GMs facing the same question, my answer would be, "Sure, why not?" Hull plating is thick and difficult to damage, but it's certainly not impossible to do this if the group shows up with enough explosives. Consider the following, though: 1. This puts every member of the gang on alert and in full combat mode. 2. Point out to the group that they don't know where in the ship Yu is if she's still alive. She might be in the Ops center. And if they made a deal to retrieve Sammy Li's keepsake, they could be inadvertently destroying that, too. 3. If the breach they make is too small, Phuong Le might just plug it with part of her body. (Have some exploded mutant babies fly out through the breach if you really want to go splatterpunk). Or, if you want her to be feistier, give her an arm or tentacle long enough to reach outside the hull and grapple the first idiot who gets too close. 4. If the gang is alerted, they might decide to fire the engines and start the trip to the sun early. If you're mean, you can have the g forces cause the docking gantry to shear off, potentially leaving PCs trapped on the the hull of a rapidly accelerating spaceship full of psychopathic cannibals. Hope that helps. :)