Italian astronaut Luca Parmitano has described his fear as water began filling his helmet during a spacewalk and he only just made it back into the International Space Station (ISS).

In a blog post Luca Parmitano said water was sloshing around, getting into his eyes and ears.

His spacewalk on July 16 with partner Christopher Cassidy was aborted once mission control heard about the leak.

Barely able to see, Luca Parmitano used his safety cable to get back to the airlock.

“As I move back along my route towards the airlock, I become more and more certain that the water is increasing. I feel it covering the sponge on my earphones and I wonder whether I’ll lose audio contact,” he wrote.

“The water has also almost completely covered the front of my visor, sticking to it and obscuring my vision.,, 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.

“To make matters worse, I realize that I can’t even understand which direction I should head in to get back to the airlock. I can’t see more than a few centimetres in front of me, not even enough to make out the handles we use to move around the station.”

Luca Parmitano has described his fear as water began filling his helmet during a ISS spacewalk

As he struggled to hear the voices of Christopher Cassidy and a mission controller, Shane Kimbrough, Luca Parmitano suddenly remembered his safety cable.

“Its cable recoil mechanism has a force of around 3 lbs that will <<pull>> me towards the left. It’s not much, but it’s the best idea I have: to follow the cable to the airlock.”

“I move for what seems like an eternity (but I know it’s just a few minutes). Finally, with a huge sense of relief, I peer through the curtain of water before my eyes and make out the thermal cover of the airlock: just a little further, and I’ll be safe.”

The trouble cropped up barely an hour into what was to be a six-hour spacewalk to perform cabling work and other routine maintenance.

NASA is investigating the incident and has suspended all of its spacewalks until the problem is fixed.

The US space agency says it is also looking more broadly at past operations and maintenance, to ensure the safety of future spacewalks.

However, two Russian cosmonauts aboard the ISS will go on a spacewalk on Thursday, to install a platform for a small optical telescope and do work on a docking assembly. Their spacesuits are very different from the US ones. The ISS currently has a crew of six.

Luca Parmitano, 36, expressed bewilderment about the source of the water, as it did not appear to have come from his drinking flask.

The scare happened during his second spacewalk.

Luca Parmitano became the first Italian to conduct a spacewalk, after arriving at the space station in May.

“Space is a harsh, inhospitable frontier and 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,” Luca Parmitano concluded in his blog post.

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