Astronaut who almost drowned during spacewalk gave three warnings to NASA

An astronaut shared the terrifying moment when he almost drowned in space.

NASA astronaut Luca Parmitano knew something was wrong when he felt water leaking into his helmet during a spacewalk.

In July 2013, Parmitano and his fellow spacewalker, Chris Cassidy, were conducting a six-hour mission outside the International Space Station (ISS).

An hour into the routine maintenance, Parmitano noticed water building up in his helmet.

At first, he thought it was a leak from his drinking bag. But as the water kept rising, he realised it wasn’t just that.

The astronaut warned NASA three times, saying that he was struggling to see, hear or communicate properly.

Luca Parmitano almost drowned when water began to leak into his helmet during a spacewalk (YURI KADOBNOV / Staff / Getty)

"I feel a lot of water on the back of my head, but I don’t think it is from my bag," he recalled.

"The leak is not from the water bag and it is increasing. I’m thinking that it might not be the water bag."

If he didn't act fast, Parmitano was in real danger of drowning in space.

Mission Control had no choice but to call off the spacewalk and Parmitano calmly managed to make his way back to the ISS airlock.

Following the incident, NASA identified that there were some design issues with the spacesuit, which had been flagged in a previous spacewalk just a week earlier.

In a blog post published on the ESA (European Space Agency) website, Parmitano opened up about the whole experience: "The unexpected sensation of water at the back of my neck surprises me – and I'm in a place where I'd rather not be surprised.

"On the ground, Shane confirms they have received my message and he asks me to await instructions.

Thankfully Parmitano survived the moment of panic (Peepo via Getty)

He continued: "Chris, who has just finished, is still nearby and he moves towards me to see if he can see anything and identify the source of the water in my helmet."

He described the liquid as 'too cold to be sweat' but regardless, it was rising.

"My ability to see – already compromised by the water – completely vanishes, making my eyes useless," he added.

"But worse than that, the water covers my nose – a really awful sensation that I make worse by my vain attempts to move the water by shaking my head.

"By now, the upper part of the helmet is full of water and I can't even be sure that the next time I breathe I will fill my lungs with air and not liquid.

As the situation became critical, he reassured himself, saying: "Now that we are repressurizing, I know that if the water does overwhelm me I can always open the helmet. I'll probably lose consciousness, but in any case that would be better than drowning inside the helmet."

Parmitano also reminded everyone: "We are explorers, not colonizers. The skills of our engineers and the technology surrounding us make things appear simple when they are not, and perhaps we forget this sometimes. Better not to forget."