Former NASA astronaut Garrett Reisman says he feared he was going to drown during a spacewalk, when a malfunction threatened to fill his spacesuit helmet with water.
"Astronaut Tip #217: Make sure your bite valve is firmly attached to your water bag straw," he tweeted this week. "When I saw mine float by INSIDE my helmet I was less than thrilled at the thought of becoming the first astronaut to drown during a spacewalk."
According to NASA documentation, its spacesuits contain a drinking bag that astronauts can access by biting down on a tube.
Needless to say, though, Reisman survived to tell the tale. He left NASA in 2011 for a position at SpaceX, where he's still an adviser, and he now teaches astronautical engineering at the University of Southern California.
"Fortunately, the surface tension proved to be enough to keep the majority of the water in the bag," he added.
Though Reisman appears never to have spoken previously about the harrowing experience, he's not the only astronaut to experience a near-drowning space.
During a 2013 spacewalk with NASA astronaut Chris Cassidy, Italian astronaut Luca Parmitano's drinking bag also started to leak into his suit — this time, it seems, even more severely.
As Parmitano's helmet filled with water, he
"I started going back to the airlock and the water kept trickling," Parmitano recalled. "It completely covered my eyes and my nose. It was really hard to see. I couldn't hear anything. It was really hard to communicate. I went back using just memory, basically going back to the airlock until I found it."
NASA was alarmed by the incident, eventually issuing a full report.
"I would say of all the EVA issues we've encountered to date, this is probably the most serious one that we've encountered," a NASA spokesperson said of the incident in 2014. "I don't know of any other failures that have had this potential hazard associated with them."
It's not clear specifically which spacewalk Reisman was on when disaster nearly struck. According to NASA, he took part in three spacewalks between 2008 and 2010 totaling more than 21 hours.
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