Reflected Sunlight

Use of Reflected Sunlight, as a Sustainable Solution for Illumination and Human Comfort at Lunar Outpost

Picture of a pavilion made out of geometrical mirrors reflecting light in different directions
  • habitats
  • moon
  • biomaterial
Project Dates:
Collaborators:

Reflected Sunlight: A Solution for Future Habitats

This project is being developed in two phases: an architectural simulation phase and a computational phase.

The project emerged from the fact that after a couple of decades of the only human settlement in outer space-the international space station is approaching its retirement. The next space exploration frontier is the Moon, then Mars. Various missions are proposing human settlement on Cislunar orbit or on the lunar surface. In such an extreme environment, the habitat designed with a pure engineering approach becomes the only space for the astronauts' existence, far away from any support from Earth. Thus, planning the human, long-term lunar exploration experts in related fields seek solutions answering technological challenges, at the same time responding to the habitability issues, ensuring not only survival but also the psychological and mental health of the inhabitants.

Diagram showing the challenges of a lunar outpost with a human drawn inside a sphere highlights in human comfort, outside of the sphere the challenges represented are 14 days cycles of day and night, micro-meteorites, harmful radiations, and extreme temperatures
Challenges for lunar outposts

Localizations and Natural Light

Due to the protection from harmful solar radiation and proximity to the most precious resource on the Moon-frozen water, it is often suggested that good localizations for the establishment of the lunar outpost are permanently dark craters. To maximize the site potential, and improve its habitability quality, we propose the use of reflected natural lighting, for the establishment of sustainable illumination solutions of these permanently shadowed outposts. The proposed system introduced as a part of the lunar outpost infrastructure uses curved mirrors to reflect light and heat from the rim to the base of the craters, while still not reflecting the high-energy harmful sun radiation. It would enable permanent control over the temperatures around the base, which reduces the need for thermal insulation on the outpost, and, at the same time, it would provide the possibility to simulate a twenty-four-hour day-night cycle imitating the human circadian rhythm, enhancing mental and physical health of the inhabitants.

End of Phase One

This phase of the project presented an investigation of the various reflective materials, metamaterials, and surface patterns, with a focus on their anti-reflectivity and reflection of high energy solar radiation, and their durability in the harsh vacuum environment, to achieve safe reflectance of sunlight to the lunar colony. The design and degree of the curvature of the mirror is decided based on iterative experimentation and computer simulations, the most efficient angle is expected to provide the desired temperatures sufficient for the colony and the adequate light and shade balance to simulate the Earth's circadian rhythm. This phase was presented at IAC2021 in Dubai, UAE.

Section of a crater showing how a mirror can be placed at the rim of the crater and two scenarios of the location of a base (one on the inner crater slopes and one at the flat bottom inside the crater). The drawing shows where the permanently shaded areas are situated within a crater of ~21 km diameter and with an inner platform of ~6,6km diameter
Possible locations of the Lunar base within a crater
Diagram showing how a small secondary mirror facing outside the rim of a crater reflects light towards a main mirror which reflects this light into the crater
Design suggestion using secondary mirrors to enable dynamic and adaptable light reflection
Section of a crater showing how a mirror can be placed at the rim of the crater and two scenarios of the location of a base (one on the inner crater slopes and one at the flat bottom inside the crater). The drawing shows where the permanently shaded areas are situated within a crater of ~21 km diameter and with an inner platform of ~6,6km diameter
One of the reflections simulations (horizontal angle -30°, vertical angle -30°)