Spacewalking astronauts installed a new ammonia pump to the International Space Station on Monday, accomplishing the urgent cooling-system repairs after more than two weeks of impaired operations in orbit.
Douglas Wheelock slid the bathtub-size pump into place after 150 minutes into the spacewalk, his third in just 10 days. He bolted the pump down as Tracy Caldwell Dyson hooked up power cables.
An initial test proved successful. “Sweet,” Wheelock exclaimed.
With that hurdle behind them, the spacewalkers then began working on the ammonia fluid lines.
If all the testing proves successful, NASA expects to have the space station’s disabled cooling loop back in action by Thursday.
The orbiting lab has been operating on only half its normal cooling capability ever since a crucial ammonia coolant pump failed July 31. It took two spacewalks, but Wheelock and Caldwell Dyson finally removed the broken pump last week.
NASA said a fourth spacewalk eventually will be needed to move the failed pump into a better storage location, but managers are uncertain whether this crew or another will carry out the work.