Thomas scans for damage
"We're going frame-by-frame through the imagery," said John Shannon, a NASA operations manager.
Engineers point out that in 25 years and 113 previous missions, shuttles have been hit by debris 15,000 times.
Adelaide's Andy Thomas, who is in space for the fourth time, is conducting a critical examination of the craft's exterior using a state-of-the-art boom with a laser attached as an added measure of safety to what is already the most scrutinised mission in shuttle history.