WASHINGTON, June 8 (Xinhua) -- Two astronauts of U.S. space shuttle Discovery's crew finished the mission's third and final spacewalk on Sunday, NASA TV reported.

During the six hour, 33 minute spacewalk, which finished at 4:28 p.m. EDT (2028 GMT), astronauts Michael Fossum and Ronald Garan accomplished all scheduled tasks and several "get-ahead" activities.

The duo continued outfitting Japan's Kibo laboratory. They removed thermal insulation from the Kibo robotic arm's wrist and elbow cameras, and launch locks from one of the forward Kibo windows. Fossum also tightened a bolt holding a Kibo television camera in place. Japanese flight controllers had noticed unexpected movement of the camera.

They then reinstalled a television camera to the left side of the International Space Station. The faulty camera had been removed during Thursday's second spacewalk, and astronauts replaced its power supply to prepare it for Sunday's reinstallation. The ground mission control has verified the repair by downlinking video of Garan from the camera.

The two spacewalkers also removed a depleted nitrogen tank assembly outside of the station and replaced it with a new one.

The spacewalk is Fossum's sixth, Garan's third, and the 112th spacewalk devoted to space station assembly and maintenance.

Discovery arrived at the station on Monday. It delivered the main part of Japan's Kibo lab. The two astronauts altogether conducted three spacewalks, outfitting the new room, which is now the biggest of the nine rooms at the orbital outpost.