Nasa's Rick Mastracchio and Mike Hopkins moving the replacement pump into place
Media playback is unsupported on your device

Astronauts repair ISS cooling pump in rare spacewalk

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.

Go to next video: Nasa broadcasts live ISS spacewalk