NASA astronauts successfully repair cooling system pump at ISS

NASA has revealed that two US astronauts have successfully repaired a critical cooling system pump at the International Space Station

Rick Mastracchio and Mike Hopkins completed a spacewalk of 7.5 hours to replace the faulty ammonia pump, the BBC reported

The pump broke down two weeks ago, leaving the US side of the station without half its cooling system

All non-essential equipment had to be switched off and many scientific experiments were halted

NASA now says all the systems should be back up and running by the weekend

It was the two astronauts’ second spacewalk in three days to replace the pump, which is about the size of a refrigerator.