Spacewalk to repair ISS coolant system continues
24 December 2013 Last updated at 16:36 GMT
Astronauts working to repair the International Space Station's cooling system are making only the second Christmas Eve spacewalk in the history of the space programme.
Half of the ammonia pumping system automatically shut down last week after abnormal temperatures were detected.
In the second of three possible outings needed to fix the issue, Nasa's Rick Mastracchio and Mike Hopkins began the task of retrieving and attaching a spare pump module.
The spacewalk is taking place on the 45th anniversary of the now iconic Earthrise photograph, taken by the crew of Apollo 8 as they orbited the Moon in 1968.
Pictures from NASA