Cryoclastic flow caused by liquid nitrogen poured on lunar dust simulant. Credit: WSU
Key points:
- Electrostatically charged moon dust is abrasive and harmful, ruining spacesuits and causing respiratory problems for astronauts.
- A team has developed a liquid nitrogen spray that quickly and easily removes moon dust from anywhere it’s not supposed to be.
- The technology is based on the Leidenfrost Effect—something very cold can handle something warmer.
Moon dust sticks to everything that it touches. It is electrostatically charged, abrasive and gets everywhere—including into engines and electronics.
During the six crewed Apollo missions to the moon in the 1960s and early 1970s, moon dust got into the astronauts’ spacesuits, destroying the seals and making some of them unusable. Astronauts also suffered from “lunar hay fever,” and researchers think a longer exposure to the dust could cause lung damage similar to that of Black Lung Disease.
That doesn’t bode well for the NASA Artemis mission, which aims to land the first woman and first person of color on the moon in 2025 with the hope of eventually setting up a base camp there for further planetary exploration.
Now, scientists at Washington State University have come up with an innovative solution. They developed a liquid nitrogen spray that can remove more than 98% of moon dust simulant in a vacuum environment with minimal damage to spacesuits, performing better than any techniques that have been investigated previously.
The technology is based on the Leidenfrost Effect, which can be seen when one pours cold water on a hot frying pan, where it beads up and moves across the pan. Similarly, spray the very cold liquid nitrogen at a warmer dust-covered material, and the dust particles bead up and float away on the nitrogen vapor.
The researchers tested their cleaning method under normal atmospheric conditions as well as in a vacuum that is more similar to outer space—and the sprayer performed better in the vacuum atmosphere.
The liquid nitrogen spray was also much gentler on spacesuit materials than other cleaning methods. While a brush caused damage to the spacesuit material after just one brushing, the liquid nitrogen spray took 75 cycles before damage occurred.
The researchers are now working to fully understand and model the complex interactions between the dust particles and liquid nitrogen that allows the cleaning process to work. They are also applying for another grant to further test the technology in conditions that more closely approximate outer space, such as in lunar gravity.
Information provided by Washington State University.