Operational Evaluation of a Photic Countermeasure to Improve Alertness, Performance, and Mood During Nightshift Work on a 105-day Simulated Human Exploration Mission to Mars
Abstract
The success of human expedition missions critically depend on the ability of the crew to be alert and maintain high levels of cognitive function while operating complex, technical equipment. Optimal human health, performance and safety during space flight requires sufficient sleep and synchrony between the circadian pacemaker-which regulates the timing of sleep, endocrine function, alertness and performance-and the timing of the imposed sleep-wake schedule.
Crewmembers of the 105-day simulation study will be required to work one night shift every sixth night. This schedule will likely result in sleep loss and circadian misalignment, especially when lighting conditions are similar to those that crewmembers experience during spaceflight. External mission controllers will work 24-hour shifts, also resulting in both sleep loss and circadian misalignment.
It has been well documented in laboratory and field studies that both working the night shift and working extended duration shifts result in decrement alertness, performance and mood. In addition to the negative effects that night shift work has on alertness, performance and mood, shift work causes significant short and long-term health problems. Shift workers, particularly night shift workers who invert their normal sleep/wake schedule, suffer for several reasons. First, their endogenous circadian rhythms and the imposed sleep/work schedule are typically out of phase. This is similar to the experience of jet lag. However, while…
How strong is the evidence?
Evidence Hub reads this as a clinical trial, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 25 participants or records.
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