Fossum smiles at the camera during EVA3 on STS-121 / Expedition 13 joint operations

S121-E-06679 (12 July 2006) --- Astronaut Michael E. Fossum, STS-121 mission specialist, works in Space Shuttle Discovery's cargo bay during the mission's third and final session of extravehicular activity (EVA). The demonstration of orbiter heat shield repair techniques was the objective of the 7-hour, 11-minute excursion outside the shuttle and the International Space Station.