The NASA Artemis missions aim to send astronauts to the moon by 2024. But to succeed, they’ll need to solve big problems caused by some tiny particles: dust.
Impacts on the moon’s surface have crushed lunar rock into dust over billions of years (SN: 1/17/19). The resulting particles are like “broken shards of glass,” says Mihály Horányi, a physicist at the University of Colorado Boulder. This abrasive material can damage equipment and even harm astronauts’ health if inhaled (SN: 12/3/13). Making matters worse, the sun’s radiation gives moon dust an electric charge, so it sticks to everything.
Horányi and colleagues have discovered a new method for combatting lunar dust’s static cling, using a low-powered electron beam to make dust particles fly off surfaces. It complements existing approaches to the sticky problem, the researchers report online August 8 in Acta Astronautica.
During the Apollo missions, astronauts relied on a low-tech system to clean lunar dust off their spacesuits: brushes. Such mechanical methods, however, are thwarted by the electrically charged nature of lunar dust, which clings to the nooks and crannies of woven spacesuit fabric.
The newly described method takes advantage of the dust’s electrical properties. An electron beam causes dust to release electrons into the tiny spaces between particles. Some of these negatively charged electrons are absorbed by surrounding dust specks. Because the charged particles repel each other, the resulting electric field “ejects dust off the surface,” says Xu Wang, a physicist also at the University of Colorado Boulder.
“This is a very unique idea,” says mechanical engineer Hiroyuki Kawamoto of Waseda University in Tokyo, who was not involved in the new work. Kawamoto and colleagues have developed their own dust-busting technologies, including a layer of electrodes that can be built into materials. When embedded in a spacesuit or on the surface of equipment, the electrodes generate electrostatic forces and fling away charged dust particles. Such systems are more complex than shooting an electron beam at surfaces, Wang says. But a potential downside to the simpler electric beam idea, Kawamoto says, is that it would require a robot or some other external means to direct it.
Another limitation of the electron beam is that it left behind 15 to 25 percent of dust particles. The researchers aim to improve the cleaning power. The team also envisions the electron beam as one of multiple approaches that future space explorers will take to keep surfaces clean, Horányi says, in addition to suit design, other cleaning technologies and, one day, even lunar habitats with moon dust mudrooms.