NASA is preparing astronauts for Mars’ dusty hazards

One of the most memorable scenes in The Martian (2015) comes just minutes into the film, when a violent dust storm forces NASA astronauts to abandon their though to be lost crewmate. While author Andy Weir has noted that Mars’ thin atmosphere couldn’t produce that kind of force his creative license got one thing very right: Mars is an extraordinarily dusty world.

That dust is expected to be among the biggest hazards for astronauts, prompting NASA to establish its first recommended exposure limits for airborne Martian dust as the agency prepares for future human missions to the red planet.

The new recommendation sets continuous exposure limits four times lower than lunar dust. The conservative threshold reflects not just the dangers already known but also what researchers still don’t know about how prolonged exposure to Martian dust could affect the human body.

These concerns aren’t theoretical. Apollo astronauts discovered that lunar dust behaved nothing like ordinary dirt. The fine, abrasive particles clung to spacesuits, worked their way into the Lunar Module and irritated astronauts’ eyes and airways after moonwalks. Apollo 17 astronaut Harrison Schmitt described experiencing what he called “lunar hay fever.”

More than 50 years later, Apollo spacesuits preserved by the Smithsonian’s National Air and Space Museum still contain lunar dust embedded in their fabric and seams.

One approach to limiting astronaut exposure to lunar or Martian dust is to leave it outside their living spaces.

NASA has spent years developing “suitports,” which keep spacesuits attached to the outside of a habitat or rover. Instead of bringing a dusty suit indoors, astronauts climb into it through a hatch in the back, complete their day’s exploration, then dock the suit back onto the vehicle before reentering the habitat, helping keep dust out of the crew’s living space.

Moon dust, or lunar regolith, is made up of pulverized rock and mineral fragments created over billions of years by meteorite impacts. Without wind or water to weather the particles, they retain sharp, jagged edges that cling to equipment and can irritate lungs and eyes

When you think of Martian dust, don’t think beach sand, think finer than baby powder, with particles about the size of those that make wildfire smoke hazardous to breathe. That allows the dust to remain suspended in the atmosphere and penetrate deep into the lungs. Unlike lunar regolith, Martian dust also contains perchlorates, reactive salts that researchers are studying for their potential health effects during the months or years astronauts could spend on the red planet.

NASA’s robotic explorers have already shown how relentless Martian dust can be. The Opportunity rover survived nearly 15 years before a global dust storm in 2018 blocked enough sunlight to end the solar-powered mission. InSight, the lander that recorded the first mars quakes, gradually lost power as dust accumulated on its solar panels.

These exposure limits set up engineers to develop better filtration systems, dust-resistant materials, contamination controls and habitat designs that keep as much of the Martian environment as possible outside. They Martian dust simulants in laboratories on Earth to refine those limits before the first astronauts arrive.

The work is already paying dividends closer to home. Building on decades of life support and air filtration experience aboard the International Space Station, engineers have developed air quality sensors to monitor fine lunar dust inside future lunar habitats for the Artemis program. Adapted for use on Earth, the same technology is now helping track air pollution, wildfire smoke and industrial emissions.