Lunar Lava-Tube Structures Characterization in Microwave Reverberating Environment

An experimental study of the microwave propagation inside a reverberating enclosure is described, focusing on the influence of lunar lava-tube simulating structures on the EM scattering and absorption behavior. Measurements of Absorption Cross Section (ACS) were performed by means of an adapted space environment simulation facility, consisting in an ultra-high vacuum chamber where inner thermal conditions and atmosphere composition may be tuned; in particular, the adopted configuration was based on the microwave characterization set-up in the frequency range $1-6 \mathrm{GHz}$ for chaotic propagation (reverberation chamber-RC). Representative lunar habitats were obtained by in-house established route to manufacture shell-shaped ilmenite-based structures and inserted within the RC environment under test; the effects of the lunar structures simulants on the environmental microwave propagation is analyzed, pointing out the need of considering such issue when next generation TLC systems concerning the in-coming lunar-and-beyond space activities will be conceived and developed.