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Lighting Protocols for Exploration: HERA Campaign (NNX15AM28G)
Principal Investigator
Research Area:
Behavior and performance
Species Studied
Scientific Name: Homo sapiens Species: Human

Space flight exposes crews to unusual light-dark and work schedules that lead to misalignment of the circadian pacemaker, resulting in poor sleep, impaired alertness, and increased risk of fatigue-related accidents. Space flight is also associated with short sleep (only approximately six hours per night) and so even in non-shifted settings, such chronic sleep deficiency will lead to impaired performance. Recently, investigators have shown that short- wavelength (blue) light is the most effective wavelength for enhancing alertness and performance directly, and for phase-shifting the circadian pacemaker. Light therefore has the potential to be a safe, non-pharmacological countermeasure to reduce the risk of performance deficits and circadian misalignment during space flight. Using blue light alone, however, is undesirable as it impairs visual function but manipulation of the blue light content of white light has similar benefits, and can optimize visual and non-visual light responses simultaneously.

NASA is replacing the current lighting aboard the International Space Station (ISS) with a new solid state lighting assembly (SSLA), incorporating three pre-determined settings to address different operational needs: 1) white light for general vision; 2) blue-enriched high intensity white light to enhance alertness and circadian adaptation; 3) blue- depleted low intensity white light to minimize alertness prior to sleep. The investigators have developed a Dynamic Lighting Schedule (DLS) which determines when each of these three settings will be used to optimize lighting to improve alertness and performance, reset circadian rhythms and enhance sleep, while maintaining vision. Laboratory-based analog studies of the DLS are ongoing. This study will extend this work to apply the DLS in the Human Exploration Research Analog (HERA) as the next step in examining the feasibility and efficacy of the SSLA system, and to provide the testing necessary to finalize the operational procedures for in-flight testing of the new light aboard the ISS.

In a series of 45-day HERA Campaign missions, investigators will conduct randomized crossover within-subject clinical trials to test the hypotheses that deployment of the DLS, as compared to deployment of a standard, static lighting schedule, and while also maintaining acceptable visual performance and color discrimination for operational tasks, will:

  1. Significantly improve polysomnographic and subjective measures of sleep latency, sleep quality, and sleep efficiency.
  2. Significantly improve cognitive performance, subjective alertness and mood, and objective EEG correlates of alertness and enhancement of EEG-derived high-alpha activity.
  3. Significantly increase the rate of circadian adaptation, as measured using the circadian rhythm of melatonin and its metabolites before and after the shift.

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Data Information
Data Availability
Archiving in progress. Data is not yet available for this experiment.

6-sulphatoxymelatonin (aMT6s), urinary peak
Cognitive performance
Sleep efficiency
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
HERA Campaign 4 05/06/2017 06/18/2018 Four 45 days One 23 days

Human Research Program (HRP) Human Research Roadmap (HRR) Information
Crew health and performance is critical to successful human exploration beyond low Earth orbit. The Human Research Program (HRP) investigates and mitigates the highest risks to human health and performance, providing essential countermeasures and technologies for human space exploration. Risks include physiological and performance effects from hazards such as radiation, altered gravity, and hostile environments, as well as unique challenges in medical support, human factors, and behavioral health support. The HRP utilizes an Integrated Research Plan (IRP) to identify the approach and research activities planned to address these risks, which are assigned to specific Elements within the program. The Human Research Roadmap is the web-based tool for communicating the IRP content.

The Human Research Roadmap is located at:

+ Click here for information of how this experiment is contributing to the HRP's path for risk reduction.

Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Pamela A. Bieri
Institutional Support
National Aeronautics and Space Administration (NASA)
Proposal Date
Proposal Source
2013-14 HERO NNJ13ZSA002N