In one of the most harrowing spacewalks in years, an astronaut had to rush back into the International Space Station today after a mysterious water leak inside his helmet robbed him of the ability to speak or hear and could have caused him to choke. Italian Luca Parmitano seemed fine after the dangerous episode, which might have been caused by a leaky drinking bag. His spacewalking partner, American Christopher Cassidy, had to help him inside after NASA quickly aborted the spacewalk. No one—neither the astronauts in orbit nor flight controllers in Houston—breathed easily until Parmitano was back inside and his helmet was yanked off.
It was the first time in years that a spacewalk came to such an abrupt halt and the first time since NASA's Gemini program in the mid-1960s that a spacewalker became so incapacitated. The two astronauts were outside barely an hour, performing routine cable work on their second spacewalk in eight days, when Parmitano reported the leak. It progressively worsened as the minutes ticked by, drenching the back of his head, then his eyes, nose, and, finally, mouth. He could have choked on the floating drops of water. His last words before becoming mum were: "It's a lot of water." The source of the leak wasn't immediately known, but a potential culprit was the 32-ounce drink bag that astronauts sip from during lengthy spacewalks. (Read more International Space Station stories.)