NASA Clears ISS Spacesuits for Routine Use

NASA has lifted a restriction on spacewalks at the International Space Station. Spacewalks using NASA spacesuits have been limited to contingencies only while engineers investigated a third incident when water built up in an astronaut’s helmet during a spacewalk earlier this year. Russian spacewalks have continued since they have their own suits with a completely different design.

The most worrisome water-in-the-helmet episode was on July 16, 2013 when ESA astronaut Luca Parmitano’s helmet filled almost completely with water. He later said he felt like “a goldfish in a goldfish bowl.” NASA determined that a clogged filter in a fan separator unit allowed the cooling water to make its way into the spacesuit itself, something thought to be impossible until then.

On January 15, 2016, NASA astronaut Tim Kopra reported a bubble of water in his helmet and an absorbent pad — a Helmet Absorption Pad installed in spacesuits after Parmitano’s incident — was wet and cold, suggesting the water was not from his drink bag, but the cooling system. The spacewalk was terminated about 2 hours early. NASA determined it was a combination of operational and environmental factors that “blocked outlet slurper holes” and was not hazardous.

Then on March 23, 2022, ESA astronaut Matthias Maurer experienced a thin layer of moisture inside his helmet as the nearly 7-hour spacewalk was ending.

He was able to doff the helmet back inside the space station without any problem, but NASA decided to bring the spacesuit back on Earth for analysis as it had the other times. It returned on the SpaceX-25 cargo mission in August.

Today NASA announced its investigation is complete. The explanation sounds similar to what NASA determined for the Kopra incident — there was no hardware failure and it was a matter of “integrated system performance.”

The team confirmed there were no hardware failures within the suit. The cause for the water in the helmet was likely due to integrated system performance where several variables such as crew exertion and crew cooling settings led to the generation of comparatively larger than normal amounts of condensation within the system.

Based on the findings, the team has updated operational procedures and developed new mitigation hardware to minimize scenarios where integrated performance results in water accumulation, while absorbing any water that does appear. These measures will help contain any liquid in the helmet to continue to keep crew safe.

Consequently, spacewalk — or extravehicular activity (EVA) — operations can return to normal.The agency said it would have further announcements soon.

During the post-landing briefing for the Crew-4 mission that splashed down last Friday, NASA ISS Program Manager Joel Montalbano described the busy ISS schedule ahead and said “we have a number of U.S. and Russian EVAs” coming up.

A total of 253 spacewalks have taken place during construction and operation of the ISS since 1998, 189 in U.S. spacesuits and 64 in Russian spacesuits.