WORLDTECHPerseverance Finds Ultrafine Martian Dust Clinging to Spacesuit Materials
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File:NASA Science Calendar 2021.pdf / NASA This image was created with Adobe InDesign . / https://eospso.nasa.gov/https%3A/eospso.gsfc.nasa.gov/publications/2021-nasa-science-calendar ( direct link ) / Wikimedia Commons / Public Domain / https://commons.wikimedia.org/wiki/File:NASA_Science_Calendar_2021.pdfSource pageNASA's Perseverance Mars rover has measured fine and ultrafine Martian dust adhering to samples of spacesuit materials it carries, including particles small enough to penetrate the lungs and enter the bloodstream. According to NASA, the results bear on how future crews might be protected on the Red Planet.
What the rover measured
Over 1,645 Martian days, Perseverance recorded dust particles clinging to swatches of spacesuit material it carries. Some of those particles are small enough to reach the lungs and pass into the bloodstream.
The team examined two spacesuit materials, Teflon and Vectran, using swatches on the calibration target of SHERLOC, an instrument on the rover's robotic arm. A Teflon sample and a basaltic glass sample on the calibration target of PIXL, a second instrument, were also analysed.
Finer particles than earlier readings
Earlier measurements on Mars resolved dust down to roughly 3 micrometres across. PIXL picked out two smaller categories: fine particles below 2.5 micrometres and ultrafine particles around 100 nanometres, about 700 times thinner than a human hair.
Particles on the Teflon target and the Vectran swatch averaged about 2 micrometres, whereas on the basaltic glass and the SHERLOC Teflon swatch sizes stretched down to about 100 to 300 nanometres.
Why static electricity matters
Static electricity appears to decide which particle sizes stick to which surface. Grains pick up a charge when they collide in the air, and distinct materials on the calibration target draw in grains of different sizes.
The finest particles stayed attached through years of driving and drilling. Organic polymers such as the Teflon found in the outer layers of spacesuits readily gathered fine dust.
Lessons from the Apollo missions
During NASA's Apollo missions, lunar dust scratched visors, degraded outer spacesuit layers and damaged seals, and some crew members reported symptoms similar to hay fever. Martian grains, rounded by wind-driven collisions, are less abrasive than lunar dust, yet they are richer in sulphur, chlorine and iron and contain more silica.
Regional and global dust storms can keep the grains circulating through the Martian atmosphere.
Open questions
- How much dust would a crew realistically carry into a habitat on Mars?
- Do the spacesuit swatch results apply directly to operational suit designs?