Spacewalk going swimmingly for astronauts with snorkels [UPDATE] HOUSTON, Dec. 21 (UPI) -- Two U.S. astronauts completed an emergency spacewalk to repair part of the International Space Station ahead of schedule and without incident, NASA said. In fact, the walk went so well the pair were able to get a head start on work scheduled for a second spacewalk Monday -- and if that trip goes according to plan they will all be able to scrap a third scheduled walk and take a day off on Christmas, NBC reported. The astronauts, Rick Mastracchio and Mike Hopkins, are two of a six-man crew manning the space station. They were forced to repair an ammonia-fueled cooling module that had failed as part of what NASA said was expected eventual maintenance to the station. The module's failure forced all non-critical systems to be shut down on the space station, which has been continuously manned since 2000. While no spacewalk is routine, officials had expressed added concern after an Italian astronaut nearly drowned during the last spacewalk when water began building up in his helmet. NASA said it was likely some previously undetected contamination in the liquid removal unit on the suit that caused the buildup. As a precaution, both Mastracchio and Hopkins wore fluid-soaking pads around their necks to enable them to detect any water buildup. Additionally, they were outfitted with snorkels inside their suits. Neither astronaut reported any kind of fluid buildup, NBC said.