Dusty denizen of deep space.
Credit: NASA/Jeff Williams

 

 

NASA’s Artemis Program to return astronauts to the Moon faces a great number of challenges. Among them is dealing with lunar dust.

A new report emphasizes that fact and also details next steps to help counter the true grit and grime of Moon exploration in coming years.

Credit: NASA

Contrasted to the Apollo human excursions on Earth’s celestial companion in 1969-1972, Artemis crews will spend considerably more time outside of their lunar landing vehicles and eventual encampments than the “dusty dozen” Apollo-era astronauts.

The report’s findings, observations, and recommendations stem from a “Lunar Dust and Its Impact on Human Exploration” workshop held February 11 – 13, 2020 that brought together leading experts in Houston, Texas.

Dust-up on the Moon. Apollo 17 commander Eugene Cernan prepares to doff lunar dust-covered space suit.
Credit: NASA

Ever present, intrusive dust

A major discovery of Apollo 11 — and the five succeeding moonwalking missions was that the surface of the Moon was covered by a several inch layer of fine dust.

“This dust layer had a negative impact on the health and wellbeing of the astronauts, and on their lunar equipment and instruments, including their spacesuits, helmets, and habitats. Surface operations and crew health were impeded by the ever present and intrusive dust,” explains the new report.

In summary, the report concludes that the dust problem “is an agency and industry concern affecting most mission subsystems and it must be addressed.”

Credit: NASA

In particular, the report continues, it is crucial that measurements and experiments be taken and carried out on the lunar surface by precursor landers to find out dust characteristics “that will influence hardware design, and provide toxicology data to safeguard crew health.”

High priority

A set of issues flagged in the report are considered “Very High Priority,” specifically:

— Characteristics of the finest fraction of the lunar soil are not well understood. The knowledge gap increases with decreasing particle size. Further, there is deficient knowledge of the variation in dust characteristics (e.g., chemical composition and mineralogy) and other characteristics of tiny particles across lunar geological regions.

— There is uncertainty in the electrical charging properties of the lunar surface and individual particles.

— Little knowledge exists about the electrical charge characteristics of regolith particles on and above the lunar surface due to the interactions with the solar wind plasma, photoemission, and secondary electron emissions.

— There has been little discussion of cabin and spacesuit (e.g., Lunar lander, Gateway) air cleaning systems.

— There is insufficient information with regard to the effect of lunar dust deposition on optical or thermal surface performance.

— While gaps exist, NASA’s Lunar Airborne Dust Toxicity Assessment Group provides significant toxicological data to guide setting a crew permissible exposure limit for dust exposure on short-term lunar missions.

— There appears to be little coordinated discussions across the agency to identify the impact of lunar dust on mechanisms, seals, connectors, and solar panels, nor are there cleaning systems identified.

— No industry-standard set of NASA requirements and oversight mechanisms exist for the manufacturing, quality control, and validation of lunar dust simulants, material that mimics Moon dust.

For each of these issues, the report fleshes out specific recommendations.

Credit: NASA

Safe levels of exposure

In wrapping up the new report’s observations, it underscores lessons learned from Apollo. For one, it became apparent that the effects of the dust on the human body, and on safety-critical equipment, had been underestimated.

In the future, the report stresses, these problems may become amplified over longer stays and any health and safety effects of lunar dust could be intensified by handling and recycling of dust in habitat life support systems, or through on-location water extraction or other operational processes, to the detriment of the crews.

“An important outcome of new investigations,” the report notes, “will be an understanding of acute versus chronic dust exposures, and establishing safe levels of exposure for long-term stays.”

The goal for future missions to the Moon, the report concludes, is to design spacecraft hardware that will operate properly and able to mitigate dust so that the crew members stay productive and healthy.

To read the full 40+ page document — Lunar Dust and Its Impact on Human Exploration: A NASA Engineering and Safety Center (NESC) Workshop – go to:

https://ntrs.nasa.gov/citations/20205008219

 

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