[MORE SPOILERS] They are shown rotating slowly, so it's sort of possible given an elastic parachute cord, but it's awfully contrived. You also have to wonder,

[MORE SPOILERS] They are shown rotating slowly, so it's sort of possible given an elastic parachute cord, but it's awfully contrived. You also have to wonder, given how slowly he drifted off, why Matt couldn't unstrap that empty thrust pack and use it as reaction mass, as Ryan does with the empty fire extinguisher later on. The bigger gaffe for me was Matt's instruction to Ryan, right after the first hit, to detach from the arm on the grounds that it would carry her too far away. That makes no sense at all. Detaching won't affect her velocity except to add a sizable random component based on the point in the arm's rotation where she detaches, and since he's already lost sight of her at that point that's going to make her much, much harder to find. All pedantry aside, loved loved loved the movie. Certainly the film of the year for me, and possibly the decade.