In this image from NASA Television, Commander Michael Lopez-Alegria, right, leaves the Russian air lock on the International Space Station to start Thursday's spacewalk. ((NASA TV/Associated Press))

Two astronauts aboard the International Space Station retracted a stuck antenna and performed maintenance as part of a record-setting spacewalk Thursday.

U.S. Commander Michael Lopez-Alegria and Russian flight engineer Mikhail Tyurin ended the six-hour and 18-minute spacewalk at 11:45 a.m. ET.

The mission set two records. Lopez-Alegria became the first U.S. astronaut to complete 10 spacewalks and it was the fifth spacewalk by the current crew — which includes U.S. astronaut Sunita Williams — a record for a single station crew.

The pair of astronauts performed a series of maintenance tasks on the station, including affixing a transmitter cable to a telescope to relay data to Earth.

They also freed a stuck antenna that had failed to retract from a cargo carrier,photographed a German experiment, swapped out and photographed a Russian experiment, and inspected and mated hardware connectors.

The spacewalk is the 81st for station assembly and maintenance in the space station's history.

The accelerated pace of work by the crew reflects NASA's plans to move away from the space shuttle program and toward establishing a base on the moon. But NASA and space agencies from other nations want to finish the space station before the shuttle program is retired in 2010.

The space shuttle Atlantis is scheduled to launch on March 15 for an 11-day mission to continue construction of the station. A Russian Soyuz spacecraft will follow soon after, launching on April 7.