One flap we know of, it is quite possible its counterpart suffered the same fate. No matter, the ship remained manoeuvrable and performed the landing flip even with half a flap - or half of two flaps - missing. That is valuable data which shows the thing can survive such damage without losing control. Now they'll need to find some way to better seal those hinge areas from the 20 minute plasma torch it is subjected to during re-entry.
