Post-EVA Lunar Day-Night Desynchronosis
Earth designation: Post-EVA Lunar Circadian Rhythm Disorder
Post-EVA presentation of Lunar Circadian Rhythm Disorder in lunar residents. Disruption of the human circadian rhythm by the lunar 29.5-day light cycle (14.7-day lunar day, 14.7-day lunar night). Human circadian rhythms entrain primarily to the 24-hour light-dark cycle of Earth. On the Moon, artificial lighting in habitats must substitute for natural light cues. Without care...
Lunar Risk Factors
Uncontrolled artificial lighting in habitat. Shift work patterns not matched to circadian protocol. Individual circadian rhythm variability. Stimulant use disrupting sleep. High stress workloads preventing adequate sleep.
Symptoms
Insomnia, daytime sleepiness, cognitive performance degradation, mood disturbance, metabolic dysregulation.
Lunar Presentation
The full lunar day (29.5 Earth days) creates two high-risk periods: early residence when residents lose Earth light cues, and long-term residence when Earth-based internal clocks drift without external synchronization.
Diagnosis
Actigraphy (wearable sleep tracking). Sleep logs. Salivary melatonin timing. Performance testing at standard times. Chronotype assessment.
Treatment
Light therapy with appropriate spectrum and timing, melatonin supplementation, sleep schedule enforcement, stimulant reduction.
Lunar Medical Bay Protocol
Circadian lighting protocol — habitat lighting programmed to simulate Earth's 24-hour light cycle regardless of lunar surface conditions. Blue-enriched white light in morning (10,000 lux equivalent). Dim warm light in evening. Melatonin 0.5-5 mg at consistent bedtime. Chronobiology consultation for persistent cases. Modafinil for essential shift work (avoid dependence). Prioritize 8-hour sleep protection in scheduling.
Evacuation Criteria
Severe performance degradation creating safety risk. Psychiatric complications from chronic sleep deprivation.
Prevention
Circadian lighting protocol from day 1. Consistent sleep schedules. Limited caffeine after early afternoon (habitat time). Chronotype-aware scheduling.