Charles Czeisler

Recognized under Tier 9 — Extraterrestrial Healthcare, Charles Czeisler conducts world-leading research in circadian biology, sleep medicine, and the health consequences of sleep disruption at Harvard Medical School. Czeisler's work on how light exposure, work schedules, and the circadian system interact to determine sleep quality, cognitive performance, and long-term health has direct and serious implications for Mars colonization. On Mars, where the day is slightly longer than Earth's, artificial lighting will be the primary circadian time cue for crew members living in enclosed habitats, and operational demands may cause chronic sleep restriction — making Czeisler's circadian and sleep science essential to maintaining crew health and cognitive performance.