He has a piece of 'shrapnel' in his leg.
(..) one of their own satellites. They shot down their own satellite? - Right of disposal. Most likely a spy sat gone bad. Now it's shrapnel. Explorer, ready to disengage HST. Locks releasing in three... two... one. - Explorer, new data coming through. What's the blowback, Houston? - It's not good. (..)2013 Gravity