The International Space Station's cooling system is broken, but no one is available to fix it because it's the weekend before Christmas. Just kidding! No one is available to replace the station's faulty, toxic ammonia-filled pump because it is in space, so the people up there have to deal with it themselves. An Italian astronaut, Luca Parmitano, nearly drowned during the station's last spacewalk in July after water began pooling in her helmet, so Americans Rick Mastracchio and Michael Hopkins were extra careful on Saturday: They wore "absorbent pads on their necks that should have picked up the first signs of excess moisture" and were prepared to abort the mission if the pads started to feel "squishy." The astronauts also brought along "jury-rigged snorkel tubes" to use in case their headgear managed to fill with fluid anyway.
It all sounds a little less high-tech than one might expect, but the trip went smoothly: On Saturday, American astronauts Mastracchio and Hopkins removed the 780-pound pump in five hours and 28 minutes — an hour ahead of schedule. The repair plan calls for them to complete two more spacewalks — one on Monday and one on Wednesday — in order to install the new pump, but their quick work today means that they might be able to call off the Christmas excursion. NASA live-streamed the process and posted an excerpt to their YouTube channel. Watching the clip is kind of soothing now that we know it doesn't go the way of Gravity.