Nasa's Rick Mastracchio and Mike Hopkins moving the replacement pump into place
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Astronauts repair ISS cooling pump in rare spacewalk

25 December 2013 Last updated at 09:41 GMT

Astronauts on board the International Space Station have successfully repaired the facility's cooling system during a seven-hour spacewalk on Christmas Eve.

A pump vital to the system broke down suddenly on 11 December, 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 - but Nasa says everything should be back up and running by the weekend.

Grainne Harrington reports.