Two astronauts at the International Space Station (ISS) began a six-hour space walk on Thursday to repair an antenna on a refuelling vessel, Russia's space flight control centre said.
"The American astronaut Michael Lopez-Alegria and his Russian colleague Mikhail Tyurin opened the station's airlock at 13:27 Moscow time and left the station," a spokesman at the centre, Valery Lyndin, told AFP.
"During their space walk, the astronauts should fix a problem with the antenna of the Progress M-58 refuelling vessel," Lyndin said.
The antenna created problems when the vessel docked at the ISS in October and could cause additional difficulties when it departs in April, the spokesman said.
The third astronaut on the station, American Sunita Williams, stayed aboard the ISS during the space walk.
Lopez-Alegria and Tyurin should also activate a new telescope recently installed on the exterior of the station that will track the flow of neutrons in space, Lyndin said.