Article Posted on : - Mar 03, 2011

Astronauts conduct the second spacewalk at the ISS. A NASA photo

WASHINGTON (BNS): Two NASA astronauts on Wednesday wrapped up their second spacewalk during space shuttle Discovery's final sojourn at the International Space Station.

The spacewalk which lasted for six-hour, 14-minutes ended at 4:56 pm Eastern time (2246 GMT), NASA said.

Astronauts Steve Bowen and Alvin Drew performed maintenance on the International Space Station, including venting ammonia from a failed pump module, during the spacewalk.

They had stepped out of the ISS at 1542 GMT Wednesday to complete work on the failed ammonia pump, remove installation on the Tranquility module and install spare parts on the Canadian robot Dextre.

The walk was briefly delayed by a minor leak in Bowen’s spacesuit, caused by a faulty O-ring seal in a lithium hydroxide canister that scrubs out carbon dioxide. A new O-ring was installed to replace it.

The duo had conducted their first spacewalk on Monday to install the Permanent Multipurpose Module onto the orbiting laboratory.

Discovery, with its six-member STS-133 crew, had docked with the ISS early on Sunday.

The spacecraft, on a 12-day mission to the ISS which will be its last space odyssey, is set to return to Earth on March 7.

Meanwhile, NASA is preparing to launch space shuttle Endeavour on its final space journey on April 19. The spacecraft will be moved to the launch pad for the last time on March 9, the space agency said.