Liquid nitrogen could keep lunar suits free of lunar dust

Annoying lunar dust is an annoying snag for astronauts landing on the moon — it sticks to just about everything. New research from Washington State University may have cracked the code for keeping spacesuits dust-free, as pressurized liquid nitrogen was used to literally blow dust off surfaces.

During testing, the research team found that a sprayer filled with liquid nitrogen can remove an average of 98% of dust adhering to fabric when used in a vacuum to simulate an air lock. The spray did minimal damage to spacesuits worn by simulated astronauts – Barbie dolls in lunar suits – as a result of the treatment. The research was published last month in space acta.

At the same time, the team found that over a total of 233 cycles in 26 spacesuit samples, the liquid nitrogen aerosol slightly degraded the spacesuit’s texture. To simulate lunar dust, the researcher used volcanic ash from Mount St. Helens, as well as materials from Offplanet Research and Exolith Labs.

In their study, the scientists wrote that lunar dust is “harmful to human health and equipment, making mitigation of paramount importance for lunar missions.” “The cryogenic liquid aerosol is a recently developed concept that is simple and suitable for dust abatement in the lunar environment.”

Astronauts on the Apollo missions to the moon used a brush to try to remove lunar dust from their suits, but this method damaged the fabric from the constant friction and harsh moon dust.

“Moon dust is electrostatically charged, it is abrasive and gets everywhere, which makes it a very difficult material to work with,” said Ian Wells of Washington State University. press release. Wells is the first author on the paper and a student in Washington State University’s College of Mechanical and Materials Engineering. “You end up with a minimum thin layer of dust that just covers everything.”

Liquid nitrogen spray ignores the use of physical corrosion in favor of the Leidenfrost effect, commonly seen when a blob of cold water dances over a hot pan, because it is insulated from the hot surface by a layer of steam underneath. Spraying works in a similar way, Wells and his colleagues say; Cold liquid nitrogen beads on a warmer spacesuit wrap dust particles before they float to the surface of the fabric.

tThe researchers cleaned the spacesuits with sweeping motions using a spray of liquid nitrogen (see center image above)., which was an effective way to remove simulated dust. aAfter spot cleaningbut, the The suits looked somewhat dirtier (see right image above), so we reached out to Wells for clarification. he he said thatIt is possible that certain sized particles were successfully removed from the suit, while others were left behind, making the suit look dirtier. Wells also suggested that the spot treatment of the suit might stir up dust that had settled after the initial sweep.

Moon dust is a very fine material, but it’s also incredibly sharp – it can, in fact, cause small tears in space suits and shoes and may even cause health problems. Apollo 17 astronaut Harrison Schmidt noted “Lunar hay fever” Moon dust sticks to the lungs and causes inflammation and congestion. Dust particles can loiter in habitats and modules on space suits, and since the moon’s gravity is much less than Earth’s, these particles will hang around much longer only to be inhaled by an unsuspecting astronaut. This is why effective spacesuit cleaning is so important.

“[Lunar dust] “It posed a lot of problems that affected missions as well as astronauts once they returned home,” Wells said in the press release.

Apparently, researchers don’t know how this spray would work inside a lunar lander parked on the Moon, where the gravity is about 16.6% of Earth’s. Also, this cleaning technology would require sprayers and vats designed for spaceflight, and missions would have to include additional charges of liquid nitrogen. With all that said, the positives seem to outweigh the negatives, making liquid nitrogen cleaning technology a worthwhile investment for future missions to the moon.

NASA is sending more astronauts to the Moon As part of the Artemis program, with two crew members Landing on the lunar south pole Not before 2025. As the Artemis program ushers in a new era of lunar exploration — with humans spending more time than ever before on the surface — an efficient way to clean spacesuits is one detail that agencies need to consider in order to promote a smooth foothold. of mankind on the moon.

This post has been updated to include Wells’ explanation of why spot-cleaning efforts seem less hygienic than a general-cleaning effort.

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