Two U.S. astronauts aboard the International Space Station spent Christmas Eve conducting a spacewalk to replace the craft's cooling system, which failed two weeks ago.
The seven-and-a-half-hour endeavor saw Mike Hopkins and Rick Mastracchio, aided by Japan's Koichi Wakata, replace a pump the size of a refrigerator. The mission was successful, said NASA's Rob Navias.
"We have a pump that is alive and well," Navias said.
Not since 1999's Hubble Space Telescope repair mission have astronauts spacewalked on Dec. 24.
"It's like Christmas morning, opening up a little present here," Mastracchio said.
While Hopkins and Mastracchio were suited up in the vacuum of space, Wakata maneuvered a 58-foot-long robotic arm inside the station.
In orbit right around the time Santa Claus would be making his rounds, the astronauts weren't as lively and quick as St. Nick.
The spacewalk didn't always go as smoothly as Santa's rounds, either.
After securing the large module, they had to switch out the valve's lines, which carry an ammonia mixture that cools the pipes and, in turn, cools the constantly running electrical equipment on the space station.
One broke free, and ammonia started spewing like snowflakes. Once that dissipated, the men completed the job but had to hang out in space while the toxic chemical that now was all over their space suits dried out.
The repair was deemed urgent by NASA, prompting the spacewalk. The crew had to turn off all nonessential equipment and use the secondary, functioning cooling line. Had that broken, the six astronauts on board might have had to abandon ship, NBC News reported.
Tracy Caldwell Dyson and Doug Wheelock, two astronauts who performed a similar repair in 2010, were at Mission Control when Hopkins and Mastracchio were in action.
"It's the best Christmas ever," Wheelock told his colleagues after the repairs were made.
"Merry Christmas to everybody," Hopkins replied. "It took a couple of licks to get 'er done, but we got it."
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