Risk of Performance Errors Due to Fatigue Resulting from Sleep Loss, Circadian Desynchronization, Extended Wakefulness, and Work Overload
Short Title: Sleep
07/30/14 12:40:58 PM (Central)
Element: Behavioral Health and Performance
RMAT Report Not Available
|Deep Space Journey
Given that astronauts experience sleep loss, circadian desynchronization, work overload, and extended wakefulness, there is a possibility a performance decrement will occur, resulting in the crew functioning poorly.
Fatigue resulting from sleep loss, circadian desynchronization, extended wakefulness, and work overload occur to some extent for ground and flight crews, prior to and during spaceflight missions. Ground evidence indicates that fatigue, as experienced by ground and flight crews, may lead to performance errors, which could potentially compromise mission objectives, and consequently the mission itself. Efforts are needed to identify the environmental and mission conditions that interfere with sleep quality, as well as individual vulnerabilities to sleep loss and circadian desynchronization. Research areas to mitigate this risk may also include: development of a self-assessment tool for cognitive function and fatigue; light therapy for phase shifting, alertness and mood disorders; individualized protocols for sleep-wake medication use; sleep dose-response recovery curves and individualized models for countermeasure implementation and optimal work-rest schedules; and other evidence-based means to improve individual sleep quality and reduce fatigue.
Reportedly, sleep loss has been an issue during spaceflight dating back to the Apollo missions. Research in current spaceflight scenarios using objective measures demonstrate that despite countermeasures, chronic sleep loss continues to exist on the Shuttle and the ISS. Anecdotal evidence reveals that work overload and extended wakefulness can also occur. Additionally, constraints imposed by mission objectives require crews, at times, shift their circadian rhythms, leading to critical tasks occurring against circadian phase. Ground research has consistently demonstrated that lack of adequate amounts of good quality sleep, circadian desynchronization, extended wakefulness and work overload can adversely affect performance capability, health and safety.
Crews on the International Space Station will continue to face these risk factors. Future missions to the moon, Mars, or other planetary surfaces will likely be both strenuous and fatiguing. Understanding the nature of sleep in space and developing mitigation strategies is therefore relevant in the current spaceflight context and in preparing for the future. Furthermore, sleep and fatigue are risk factors for the other Behavioral Health and Performance Risks (Risk of Performance Errors Due to inadequate Team Cohesion and Performance, Inadequate Selection/Team Composition, Inadequate Training, and Poor Psychosocial Adaptation; Risk of Adverse Behavioral Conditions; and Risk of Psychiatric Conditions), as well as other aspects related to human health. It is therefore essential to develop countermeasures for issues related to sleep loss, circadian desynchronization, extended wakefulness and work overload. BHP research activity aims to assess this risk as well as provide adequate standards and countermeasures for exploration missions.
The risk mitigation strategy of the BHP Element follows the larger strategy of the HRP "from Evidence to Deliverables” principle, with the involvement of Medical and Mission Operations to help determine the tools and technologies that are relevant for current and future spaceflight. BHP holds an annual working group of subject matter experts who work with BHP and Medical Operations to identify gaps in knowledge and gaps in mitigation. Specific tasks are defined to address the gaps and provide clear, specific deliverables for long duration spaceflight, ensuring an evidence and operationally-based end item. Working with research and operational experts, BHP systematically identifies the appropriate platform to address the gaps prior to validating in spaceflight. To ensure relevancy, stakeholders are engaged in the process from the beginning. Evidence gathered from BHP research characterize Risk, inform Operations and Standards, and yield countermeasures for performance and behavioral health.