Space station astronaut Rick Mastracchio may get his Christmas wish for a spacewalk or two because of a broken cooling system.
In an interview Friday with The Associated Press, Mastracchio said from the International Space Station that he's more than ready to go out and fix it, if deemed necessary by Mission Control. He calls it a "good news, bad news" situation.
One of two space station cooling loops shut down Wednesday. Flight controllers suspect a bad valve inside a pump. On Friday, engineers in Houston spent the third straight day trying to solve the problem.
The cooling system uses ammonia to dispel heat generated by on-board equipment. The six astronauts have turned off non-essential equipment to reduce the heat load, including many experiments.