Lunar Regolith Particles In Outposts

Abstract

The US, India, China, Japan, and Europe plan for future crewed lunar missions. While mission architecture may be superficially similar to the American Apollo program of the 1960s and 1970s, future missions will vary considerably from that precedent in duration and complexity. Long-duration lunar stays with tens of extravehicular activities per mission will expose crews and equipment to lunar regolith dust for increased periods. Lunar regolith soil (fragments under 1 cm in diameter) is primarily constituted of poorly sorted, highly irregular agglutinated silicates, the result of the fragmentation of the young lunar crust by meteoroid impacts, followed by the mixing of the lunar surface by meteoroid and micrometeoroid impacts and radiation for over 4.5 billion years. Regolith contains particulate matter (PM) recently conclusively shown to include the fine and ultrafine regimes (diameters <2.5 µm and <0.1 µm, respectively). The correlation between elevated cardiovascular risks to human health and ultrafine particles is well-established in the scientific literature. The success of future long-duration lunar missions will hinge on the development of effective lunar suits, vehicles, and habitats. Understanding the mechanisms of lunar regolith PM exposure, deposition, resuspension, and tracking will be key to developing such equipment. This paper reviews the literature of lunar PM petrography, lunar mission histories, aerosol science, and medicine, with the intent of aiding designers of lunar mission human factors equipment. A model is proposed for determining lunar regolith PM migration into a hypothetical crew compartment from a given airlock volume. The authors further propose a novel inflatable airlock configuration to mitigate such PM migration.