HEPA references: all references related to HEPA filters were obtained from vendor's sites.

References:

• Toxicity of lunar dust, Dag Linnarsson et al., 2012;
• The Apollo Experience Lessons Learned forConstellation Lunar Dust Management, Sandra A. Wagner, 2006.
• https://pubchem.ncbi.nlm.nih.gov/compound/11199
• https://pubchem.ncbi.nlm.nih.gov/compound/1030

HEPA absolute filter

The HEPA Absolute Filter model consists of a mesh of randomly arranged glass fibers with diameters between 0.5 and 0.2 µm, which, although larger than many particles, are capable of very fine filtration effective.

Absolute Filter efficiency is achieved through three steps: trapping particles that are adhered to the filter element, impacting larger particles that obstruct the passage through the fibers and reduce the passage space and, finally, the diffusion, in which Smaller particles are blocked by larger particles that are accommodated between the fibers.

Polyvinyl Alcohol (CH2CHOH)

Is a synthetic polymer that is soluble in water. It is effective in film forming, emulsifying, and has an adhesive quality. It has no odor and is not toxic, and is resistant to grease, oils, and solvents

Organoleptic characteristics: yellowish powder.

Melting Point (powder): 463K

Melting Point (Hydrated Powder): 503K

Biodegradable.

https://pubchem.ncbi.nlm.nih.gov/compound/11199

Lunar Regoliths

Composed of basalt, feldspar and other minerals. There is on the lunar surface armalcolite, formed by iron oxide, titanium and magnesium.

Density: 1.5 g / cm³

Particles of less than 60-80 micrometer size.

They contain submicroscopic iron.

May have a percentage of pyroclastic material (solid rock fragments that are blown into the air by a volcano eruption), glass and lithic fragments (broken rocks)

Regolith contamination presented many challenges for the Apollo missions. In addition to damage to vehicles and equipment, astronauts have reported symptoms related to dust exposure and inhalation can have a number of toxic effects on humans. Identifying the mineralogical and chemical composition immediately can provide in situ geological mapping for landing sites where less dust can be raised. Considering static and the movement of the team due to their extravehicular activities, 2 applications of terrestrial technologies are proposed.

Messages exchanged by the Apollo 12 team report that depressurization was interesting at first. With Artemis in mind, a depressurization system coupled with absolute HEPA (High Efficiency Particulate Air) filters using glass microfibers with an efficiency of up to 99.995% for particles up to 0.3 µm is proposed. Filters can also be used in critical internal areas to protect equipment where adhesion may occur. For extravehicular activities, a Peel-off technology film is proposed that covers the garments so that, upon return to the module, it can be torn off, discarded and degraded in the external environment, without the need to carry particles into the interior. vehicle during its disposal."