Astronaut Jeffrey N. Williams, mission specialist, returns to the shirt-sleeve environment of the Space Shuttle Atlantis following a 6-hour, 44-minute space walk to work on the exterior of the International Space Station. Astronauts Williams and James S. Voss secured a United States-built crane that was installed on the station last year; installed the final parts of a Russian-built crane on the station; replaced a faulty antenna for one of the station's communications systems; and installed several handrails and a camera cable on the station's exterior.