Astronauts discuss the aborted spacewalk aboard the International Space Station on Tuesday. A dangerous water leak in the helmet of Luca Parmitano, bottom center facing camera in white suit, drenched his eyes, nose and mouth, preventing him from hearing or speaking as what should have been a routine spacewalk came to an abrupt end.
CAPE CANAVERAL, Fla. — In one of the most harrowing spacewalks in decades, an astronaut had to rush back into the International Space Station on Tuesday after a mysterious water leak inside his helmet robbed him of the ability to speak or hear at times and could have caused him to choke or even drown.
Italian Luca Parmitano was reported to be fine after the dangerous episode, which might have been caused by an unprecedented leak in the cooling system of his suit. His spacewalking partner, American Christopher Cassidy, had to help him head inside after NASA quickly aborted the spacewalk.
No one — neither the astronauts in orbit nor flight controllers in Houston — breathed easier until Parmitano was back inside and his helmet was yanked off.
"He looks miserable. But OK," Cassidy assured everyone.
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. Spacewalking always carries high risk; a puncture by a micrometeorite or sharp edge, if big enough, could result in instant death.
In a late afternoon news conference, NASA acknowledged the perilous situation that Parmitano had found himself in, and space station operations manager Kenneth Todd promised to "turn over every rock" to make sure it never happens again.
Spacewalking is dangerous already, noted flight director David Korth. Then on top of that, "go stick your head in a fishbowl and try to walk around. That's not anything that you take lightly," he said. "He did a great job of just keeping calm and cool" as the amount of water ominously increased.
"Grace under pressure," Korth said.
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 by the time he was in the air lock, the pressure chamber. He could have choked or drowned on the floating globs of water, NASA officials said.
Between 1 and 1½ liters of water leaked into his helmet and suit, NASA estimated.
The source of the leak wasn't immediately known, but the main culprit appeared to be iodine-laced water that is piped through the long underwear worn under a spacesuit, for cooling. The system holds nearly 4 liters, or 1 gallon. Less likely was the 32-ounce (about 1 liter) drink bag that astronauts sip from during lengthy spacewalks; Parmitano reported the leaking water tasted odd.
At first, Parmitano, 36, a former test pilot and Italy's first spacewalker, thought it was sweat accumulating on the back of his bald head. But he was repeatedly assured it was not sweat. He agreed. "How much can I sweat?" he wondered aloud.
It was only his second spacewalk; his first was last Tuesday, six weeks after moving into the space station.
The water eventually got into Parmitano's eyes. That's when NASA ordered the two men back inside. Then the water drenched his nose and mouth, and he had trouble hearing on the radio lines.
Cassidy quickly cleaned up the work site, then joined Parmitano in the air lock.
The three Russians and one American who anxiously monitored the drama from inside hustled to remove Parmitano's helmet. They clustered around him, eight hands pulling off his helmet and using towels to mop his head. Balls of water floated away.
Parmitano blinked hard several times but otherwise looked fine as he gestured with his hands to show his crewmates where the water had crept around his head.
Cassidy told Mission Control: "To him, the water clearly did not taste like our normal drinking water." A smiling Parmitano then chimed in: "Just so you know, I'm alive and I can answer those questions, too."