Two U.S. astronauts from the shuttle Atlantis have conducted a third and final spacewalk at the International Space Station.
Robert Satcher and Randy Bresnik ventured into open space Monday for the walk that lasted nearly six hours. The two worked to attach a new oxygen tank at the orbiting outpost and installed a unit to conduct experiments.
The space outing was delayed about one hour to fix a problem with one of the astronaut's suits.
The astronauts accomplished extra work during the first two spacewalks, so only a few tasks remained for the third.
Atlantis is scheduled to return to the Kennedy Space Center in Florida Friday following the 11-day mission, in which the shuttle carried more than 13 tons of spare parts to the outpost.
The shuttle mission is NASA's last of the year. The crew will return with astronaut Nicole Stott who has spent three months on the space station.