Two Astronauts Take Space Walk To Fix International Space Station

Two astronauts take a Christmas Eve space walk more than 200 miles above Earth.  

The two American astronauts are on a mission to replace the pump needed to cool the vessel at the International Space Station.
They were able to remove the broken pump this past weekend, but today they are putting in a working pump.  
 The new equipment contains ammonia making the installation a little more dangerous.
Retired Astronaut Chris Hadfield says, “Some of the danger is hooking up the big heavy ammonia lines. They're really thick and massive, and hooking those up of course if you were to leak ammonia it's not a very pleasant chemical you couldn't bring it inside so there's definite risk out there.”
NASA hopes all the work will be done by Christmas, allowing the astronauts time to celebrate the holiday safely inside the space station.