Water causes a fresh problem for space station’s spacewalkers 

NASA delays second spacewalk 1:45

The first spacewalk to repair the International Space Station's cooling system went better than expected, but afterward, NASA encountered a new problem.

After Saturday's five-hour, 28-minute outing to remove a faulty coolant pump module, astronaut Rick Mastracchio returned to the space station's Quest air lock and discovered something that wasn't supposed to be. Water had entered his spacesuit sublimator — a device that's designed to dissipate excess heat.

"There's always been water in the suit," longtime NBC News space correspondent Jay Barbree said. "The difference is, they had devices that got rid of it. This time, it accumulated."

The excess water is the reason why the next repair spacewalk, aimed at installing a replacement pump module, was postponed from Monday to Tuesday. The extra time will give the station's crew a chance to reconfigure a spare spacesuit for Mastracchio's use.

NASA's spacesuits have water-based systems that remove moisture and cool the astronauts while they work. One of those systems malfunctioned in July, and that resulted in a near-drowning for Italian spacewalker Luca Parmitano. Mission managers said that malfunction was apparently caused by a clogged filter. After the crew checked the spacesuits and replaced some parts, NASA gave the suits a clean bill of health. As an added precaution, the suits are now equipped with absorbent pads and makeshift snorkels.

NASA said the problem affecting Mastracchio's suit is not the same as the one that cropped up in July. The other spacewalker working on repairs, Mike Hopkins, was wearing Parmitano's suit on Saturday and reported no difficulties.