Video: NASA officials preview space station battery replacement spacewalks

Space station commander Scott Kelly and Kjell Lindgren carried out a busy but mostly trouble-free spacewalk Friday, routing ammonia coolant back to the prime radiator used by one of the lab’s solar arrays and bypassing a secondary radiator that was activated three years ago to help pinpoint a coolant leak.

After a bit of a struggle with a balky bolt, space station commander Peggy Whitson replaced a failed external computer during a short, hurriedly planned spacewalk Tuesday while crewmate Jack Fischer installed a pair of antennas to improve wireless communications during future excursions.

The 10th dedicated cargo delivery mission by SpaceX’s Dragon spacecraft, and the first to liftoff from launch pad 39A at NASA’s Kennedy Space Center, will carry more than 5,000 pounds of equipment to the International Space Station.