The cooling system has been restored to full functionality

Dec 27, 2013 13:01 GMT  ·  By
NASA astronauts Rick Mastracchio and Michael Hopkins can be seen here during an EVA conducted on December 24, 2013
   NASA astronauts Rick Mastracchio and Michael Hopkins can be seen here during an EVA conducted on December 24, 2013

Astronauts with the Expedition 38 crew aboard the International Space Station had a busy Christmas season. On December 24, NASA astronauts Rick Mastracchio and Michael Hopkins ventured outside the space lab in an extravehicular activity (EVA), which fixed an issue that has been plaguing the station for more than two weeks. 

Loop A of the station's cooling system experienced a glitch with one of its valves a while back, so Mission Control in Houston, Texas, had to ask Expedition 38 crew members to switch most systems over to Loop B of the cooling system. This placed undue pressure on the second cooling loop.

After trying to address the issue in a variety of ways, NASA experts finally decided to opt for a solution where astronauts had to conduct a series of three EVA outside the station. The second of these spacewalks occurred on Christmas Eve, at 1153 GMT, Space reports.

The first EVA took place on Saturday, December 21, and was successfully completed in less than six hours. The main goal for the astronaut duo was to replace an ammonia pump module, which contained the failed flow control valve. This was achieved at the end of the 7-hour, 30-min spacewalks on Tuesday.

On Saturday, the astronauts were able to remove the 355-kilogram (780-pound) pump module, and then safely store it away outside the International Space Station. Originally, the second part was supposed to take place during the second EVA, but Mastracchio and Hopkins moved more quickly than anticipated.

All that was left for them to do on Tuesday was to grab a hold of the new ammonia pump module, and insert it in its correct receptacle on the ISS starboard side backbone truss rod. Though the module was the size of a refrigerator, the astronauts had no trouble swiftly maneuvering it into place.

All in all, it took about 10 days for NASA and the ISS crew to fix the cooling system issue, from when the problem was first reported to when the last screw was tightened on the new module.

Despite cramming three EVA-worth of jobs in two, astronauts on the station will still conduct a third spacewalk today, December 27. Russian Federal Space Agency cosmonauts Oleg Kotov and Sergey Ryazanskiy will step outside the ISS to refresh some scientific experiments attached to the outer hull of the spacecraft.

Additionally, the Russian duo will also install a couple of high-resolution cameras outside the station, which will enable Mission Control and Expedition 38 astronauts to become more aware of what is going on around the ISS.