Scientists develop ‘dustbuster’ for lunar astronauts
Image credit: NASA
Researchers in the US have devised a method that allows astronauts exploring the Moon to clear lunar dust off their gear.
The technique, created by researchers at the University of Colorado Boulder, involves using electron beams for cleaning fine particles off surfaces. For this, the team took aim at a Nasa-made Moon dust substitute – known as lunar regolith – with “a device that shoots out a concentrated (and safe) stream of negatively charged, low-energy particles.”
In the new study, the team aimed such a tool at a range of dirty surfaces inside a vacuum chamber: spacesuit fabric and glass were used as surface materials to simulate the space environment. The researchers found with this technique that the dust flew off. “It literally jumps off,” said lead author Benjamin Farr.
According to the researchers, they still have a long way to go before real-life astronauts will be able to use the technology to do their daily tidying up. However, Farr said, the team’s early findings suggest that electron-beam dustbusters could be a fixture of Moon bases in the not-too-distant future.
Several space pioneers have raised issues concerning lunar dust in the past, which often resists attempts at cleaning even after vigorous brushing. Harrison 'Jack' Schmitt, who visited the Moon as a member of Apollo 17 in 1972, developed an allergic reaction to the material and has said that it smelled like “spent gunpowder”.
According to Xu Wang, a research associate in the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder, the problem with lunar dust is that it isn't anything like the stuff that builds up on bookshelves on Earth.
“Moon dust is constantly bathed in radiation from the sun, a bombardment that gives the material an electric charge,” he explained. “That charge, in turn, makes the dust extra sticky, almost like a sock that's just come out of the drier. It also has a distinct structure.”
Electron beams offered a promising solution. According to a theory developed from recent scientific studies of how dust naturally lofts on the lunar surface, such a device could turn the electric charges on particles of dust into a weapon against them.
Wang explained: “If you hit a layer of dust with a stream of electrons, that dusty surface will collect additional negative charges. Pack enough charges into the spaces in between the particles and they may begin to push each other away, much like magnets do when the wrong ends are forced together. The charges become so large that they repel each other and then dust ejects off of the surface.”
According to Wang, this new technology aims at cleaning the finest dust particles which are difficult to remove using brushes. The method was also able to clean dusty surfaces by an average of about 75-85 per cent.
The researchers are currently experimenting with new ways to increase the cleaning power of their electron beam. Mihály Horányi, a professor in LASP and the Department of Physics at CU Boulder, said that the technology has real potential.
Nasa has experimented with other strategies for shedding lunar dust, such as by embedding networks of electrodes into spacesuits. An electron beam, however, might be a lot cheaper and easier to roll out, according to the researchers.
Horányi envisions that one day, lunar astronauts could simply leave their spacesuits hanging up in a special room, or even outside their habitats, and clean them after spending a long day kicking up dust outside. The electrons would do the rest. “You could just walk into an electron beam shower to remove fine dust,” he said.
In July 2019, Nasa reached out to university students to seek new ideas for dealing with the issue of lunar dust. “It’s abrasive and can damage things, including spacesuits, equipment, spacecraft and habitats,” the agency said. “Dust can obscure camera lenses; reduce technology performance; distort instrument readings; alter thermal properties, and even cause equipment failures.”
Dealing with the dust will likely require a multipronged approach. Nasa is also developing a coating technology that could help keep dust off lunar exploration gear.
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