Washington: US astronauts completed on Monday the first of three planned spacewalks from the shuttle Atlantis a day after the craft docked with the International Space Station.
Astronauts Garrett Reisman and Stephen Bowen finished the seven-hour, 25-minute spacewalk at 3:19 pm (1919 GMT) after installing a second space-to-ground communications antenna and a spare parts platform on Dexter, the two-armed robotic device on the orbiting ISS.
It was the 237th spacewalk by US astronauts, the second for Reisman and the fourth for Bowen, NASA said.
The pair meanwhile loosened battery bolts on the port-6 backbone segment of the station in preparation for the other spacewalks.
Atlantis brought to the station six new 375-pound (170-kilogram) batteries to be installed during the second and third spacewalks.
The shuttle and its crew of six successfully docked with the orbiting space lab on Sunday about 220 miles (350 kilometers) above the South Pacific.
The mission is the 32nd and final scheduled voyage for Atlantis, which first launched in 1985 and has logged some 115 million miles in its career.
Only two more shuttle launches remain -- one in September for Discovery and the final blast off for Endeavour in November -- before the curtain falls on this era of human spaceflight.
The United States will then rely on Russia to take astronauts to the station aboard three-seater Soyuz spacecraft until a new fleet of commercial space taxis is operational.
During a mission of almost 13 days, most of which will be spent moored to the ISS, Atlantis and her crew will unload more than 12 tons of equipment, including the communications antenna, power storage batteries, and a radiator.
The biggest single element is the five-ton Rassver research module, or MRM-1, which will provide additional storage space and a new docking port for Russian Soyuz and Progress spacecraft.
The Rassver -- "Dawn" in Russian -- will be permanently attached to the bottom of the space station`s Zarya module and carries important hardware on its exterior including a radiator, airlock and a European robotic arm.