A technical solution for windows in mass-screened Lunar habitats

In recent years, a renewed interest in lunar exploration has arisen once again. A review of the research on exploration of the Moon shows that there are significant challenges related to establishing a base for humans in the harsh lunar environment. If the Earth's surface is protected by its magnetosphere and its atmosphere against cosmic radiation, solar flares, and micrometeorite impacts, the lunar surface, instead, has no magnetic field that deflects charged particles and no radiation-absorbing and micrometeorite-consuming atmosphere at all. The possibility of protecting human beings from radiation and micrometeorites by exploiting passive shielding techniques, using the locally available regolith to build a thick massive envelope, is effective, but it has an intrinsic drawback: the buildings must have small viewports, or even no viewports at all. Numerous studies conducted since the 1950s in harsh terrestrial environments such as deserts, undersea habitats, and Antarctica have shown that Habitability and Human Factors (H&HF) in Isolated and Confined Environments (ICEs), like lunar habitats, are critical for the well-being of crew members. Among these factors, the capability to have an external view is essential. In lunar habitats the integration of passive radiation shielding with viewports or vision systems can enhance psychological well-being, reduce stress, improve spatial awareness and facilitate the monitoring of external activities. However, the technical solutions developed so far, such as small observation posts with protective shutters or digital virtual screens, do not allow for or limit direct and continuous external view. The paper proposes an optical virtual window based on image reflection that is compatible with a massive structure, allowing direct observation while protecting against radiation exposure and impacts of micrometeorites. This technological system enables the direct view of the external environment, mitigating psychological effects derived from long stays in ICEs, enhancing operational task control, with positive effects on the safety of the crew.