What to Do When Your Space Helmet Fills With Water

This week's NASA report on a near-fatal spacewalk reads like something out of your worst nightmare.

Italian astronaut Luca Parmitano spent nearly an hour floating in space as his helmet slowly filled with water—up to 1.5 liters—engulfing his eyes, nose and ears. And while his July 16 spacewalk ended safely, NASA now acknowledges the mishap could have killed him.

"[Parmitano] experienced a large amount of water collecting inside his helmet which created several hazardous conditions including risk of asphyxiation, impaired vision, and a compromised ability to communicate," the report states. "The presence of this water created a condition that was life threatening."

As the water collected, Parmitano's concerns were initially dismissed. The report says crew members were under the misperception that astronauts' drink bags leaked frequently, and reacted as if the collecting water was due to that less-serious problem.

In a 16-minute span, however, Parmitano said three times he did not believe the water was coming from the drink bag. Only after he drank the bag's remaining water did the team consider other possibilities. A fellow astronaut surmised urine or sweat may be to blame.

Meanwhile, his helmet was still filling up. Another misperception—that water in zero-gravity would cling to the inside of the helmet and not an astronaut's face—led crew members to underestimate the problem.

Twenty-four minutes after his first report of the problem, Parmitano's spacewalk was terminated. It would be another 33 minutes before his helmet would come off.

As he made his way back to the airlock, gathering water covered his eyes, forcing him to blindly feel his way toward the station. The crew inside and back on the ground were still unaware of how serious the situation was, because Parmitano's soaked communications cap was not relaying his calls—leaving him "in the blind."

One hour and 35 minutes after the start of his spacewalk, Parmitano—finally in the airlock—removed his helmet. While most of us are having a panic attack just reading about his ordeal, the Italian's "calm demeanor in the face of his helmet filling with water possibly saved his life," says the report.

NASA's 222-page document also credits the flight control team for making the correct calls in an unprecedented situation, ultimately saving Parmitano's life.

So what caused the near-fatal accident? According to the report, a blocked water separator in the suit caused the liquid to spill over and find its way into the astronaut's helmet.