Nature of Radiation
Solar rays consist of X-rays and gamma rays, immaterial particles, electrons and protons — emitted continuously and travelling at 500 km/s. On Earth, we are protected by the terrestrial magnetosphere and atmosphere. On the Moon, these protections do not exist.
To this are added solar flares, following a ten-year cycle, emitting particles of considerably higher intensity than ordinary emissions. These events constitute the most sudden and dangerous threat to any extraterrestrial human presence.
Doses and Critical Thresholds
The unit of measurement is the rad: an irradiation of 25 rads is dangerous for humans; 100 rads represents the critical survival threshold; 400 rads leads to near-instantaneous death. Some radiation injuries only appear years after exposure, or even in descendants — making the problem all the more insidious.
Architectural Solutions
Architectural radiation protection can use different materials: 148 cm of aluminium, 35 cm of lead, or 200 cm of lunar regolith. The latter, available in situ and at no cost, is the most economical and rational solution for protecting inhabited structures.
The project integrates this data at several levels: lower levels buried in regolith benefit from natural protection; emerging structures are covered with lunar backfill; maximum protection shelters allow occupants to take refuge in the event of an imminent solar flare.
The crater topography itself is exploited as a natural shield: the rocky walls of the site intercept a large portion of grazing radiation, reducing the exposure of built volumes.
"Lunar regolith is not waste to be managed — it is the raw material of free, on-site, unlimited radiation protection."
Croquis de recherche
Regolith compressed into blocks provides both structure and radiation protection.