CAPE CANAVERAL, FL (AP) - Spacewalking astronauts have completed a key step toward fixing the cooling system on the International Space Station.
They installed a new ammonia pump today, a couple of hours into a spacewalk - the third in just 10 days.
While one crew member bolted the pump into place, another one hooked up power cables. If tests are successful, NASA hopes to have the disabled cooling loop back in action by Thursday.
It hasn't been working properly for more than two weeks.
NASA said a fourth spacewalk eventually will be needed to move the failed pump into a better storage location.