Two U.S. astronauts of space shuttle Endeavour's crew have finished the second of four planned spacewalks of the mission on Thursday, continuing the repair job for the International Space Station's right-side solar array joint, NASA TV broadcast.

Mission specialists Heidemarie Stefanyshyn-Piper and Shane Kimbrough wrapped up their service call at 7:43 p.m. EST on Thursday (0043 GMT on Friday).

US space shuttle Endeavour Mission Specialists Heide Piper (Lwr L) and Shane Kimbrough (Top C ) on November 20, 2008 as they clean and lubricate one of the Solar Alpha Rotary Joints on a truss of the International Space Station during the second of four planned spacewalks for the STS-126 mission.[AFP PHOTO/NASA VIDEO]

During the most time of their six hour and 45 minutes spacewalk, they continued to clean and lubricate a massive joint on the right-side solar panels outside the space station.

This balky gear has had limited use since September 2007. It will take all of the four spacewalks to be totally running well again. In Tuesday's first spacewalk, Piper and another spacwalker kicked off the challenging repair work.

As a precaution, spacewalker will also lubricate the left-side solar array joint in the next several days. These two wagon-wheel-shaped joints can allow the electricity-generating solar arrays to rotate so that they're always getting as much sun as possible.