Article Posted on : - Apr 09, 2010

NEW DELHI (BNS): US space shuttle Discovery astronauts on Friday began the first of three scheduled spacewalks.

Mission Specialists Clayton Anderson and lead spacewalker Rick Mastracchio configured an old Ammonia Tank Assembly (ATA) for removal and prepared a new ATA for installation, a NASA statement said.

On the center-most portion of the International Space Station’s backbone, they replaced a Rate Gyro Assembly, part of the station’s navigation system.

The duo will perform two more spacewalks during their time at the station. Anderson and Mastracchio performed two spacewalks together during the STS-118 mission in August 2007.

On Wednesday, Shuttle Discovery successfully docked with the International Space Station (ISS) manually after a malfunction on board the shuttle.

Discovery blasted off on schedule at 6:21 a.m. local time (14:21 GMT) on Monday from the Kennedy Space Center in Florida on one of NASA's final stockpiling missions to the ISS.

This is Discovery's 33rd mission to the ISS, and the 131st mission of the Space Shuttle program.

The current mission will last 13 days and astronauts will perform three space walks, each of which is planned to last around six and a half hours.