Xmas Spacewalk Planned for Space Station Fix Cooling system in urgent need of repair By Rob Quinn, Newser Staff Posted Dec 17, 2013 11:19 PM CST Updated Dec 18, 2013 12:01 AM CST 2 comments Comments Three spacewalks will take place at the ISS over the next week. (AP Photo/NASA) (Newser) – Before they can tuck into their freeze-dried turkey dinners, two American astronauts are going to have to venture out on a spacewalk to fix a faulty pump that has shut down part of the International Space Station's cooling system. The Christmas Day spacewalk is one of three that NASA has scheduled over the next week to carry out the repairs, which have delayed the launch of a private cargo spacecraft, Space.com reports. The problem started last week, when the fault forced the station to close down one of its two ammonia cooling systems, reports Voice of America. The six-member station crew—the two Americans plus three Russians and a Japanese astronaut—is not in any danger; the shutdown has halted a lot of research and if a problem arises with the second cooling system before the first one is fixed, the crew could be forced to return to Earth early.