Dust Mitigation Strategies Enabling Moon Exploration Missions

Abstract

Micrometric dust particles of lunar regolith represent one of the most serious issues of the harsh Moon environment. Indeed, the extremely high vacuum conditions expose the lunar soil minerals to intense ultraviolet and galactic cosmic rays’ bombardment during the Moon’s daylight producing photoionization of the constituent’s atoms and electron release. Moreover, the Moon periodically interacts with the surrounding solar wind which generates a continuous flux of charged particles accompanied by electric fields around the terminator region able to lift off the lunar regolith dust up to ~100 km above the geometrical surface. In this way, micrometric granular matter forms a subtle veil of contaminants. This electrically charged and extremely adhering dust environment not only can cause various critical drawbacks to several robotic parts, e.g., mechanical components, electronic devices, solar panels, thermal radiators, rover seals and bearings, etc. but also can dramatically damage the respiratory systems of humans if accidentally inhaled. For these reasons, lunar dust was recognized, by several agencies including NASA and ESA, as one of the main hazards for the ongoing robotic and manned exploration and colonization of our natural satellite. To overcome or at least mitigate these issues, several technologies were developed and assessed ranging from the active ones requiring a source of energy, e.g., mechanical, fluidal, and, above all, electric devices, to the passive technologies involving suitable material design and development. The work here reported presents several possible active and passive chemical and physical strategies for protecting sensitive surfaces of space systems against granular contamination. This paper is intended as a survey of dust mitigation issues and technical mitigation with the approach pursued by the Italian Aerospace Research Centre (CIRA) related to a hybrid technique with an innovative material. The strategy that is under implementation by CIRA is based on the combination of active and passive techniques and consists of the design and development of innovative high-performance polymers exhibiting simultaneously outstanding thermo-mechanical properties and superior non-sticking capacity, i.e., abhesion.