Testing Solid State Lighting Countermeasures to Improve Circadian Adaptation, Sleep, and Performance During High Fidelity Analog and Flight Studies for the International Space Station (Lighting Effects) - 02.08.17
The light bulbs on the International Space Station are being replaced with a new system designed for improved crew health and wellness. The Testing Solid State Lighting Countermeasures to Improve Circadian Adaptation, Sleep, and Performance During High Fidelity Analog and Flight Studies for the International Space Station (Lighting Effects) investigation studies the impact of the change from fluorescent light bulbs to solid-state light-emitting diodes (LEDs) with adjustable intensity and color and aims to determine if the new lights can improve crew circadian rhythms, sleep, and cognitive performance. Results from this investigation also have major implications for people on Earth who use electric lights. Science Results for Everyone
Information Pending Experiment Details
OpNom: Lighting Effects
George C. Brainard, Ph.D., Thomas Jefferson University, Philadelphia, PA, United States
Steven W. Lockley, Ph.D., Brigham and Women's Hospital, Boston, MA, United States
Laura K. Barger, Ph.D., Harvard Medical School, Brigham and Women's Hospital, Boston, MA, United States
Charles A. Czeisler, Ph.D., M.D., Harvard Medical School, Brigham and Women's Hospital, Boston, MA, United States
Toni Clark, NASA Johnson Space Center, Houston, TX, United States
James Maida, NASA Johnson Space Center, Houston, TX, United States
Jason P. Sullivan, Brigham and Women's Hospital, Boston, MA, United States
Joseph M. Ronda, M.S., Brigham and Women's Hospital, Boston, MA, United States
Shadab A. Rahman, Ph.D., Brigham and Women's Hospital, Boston, MA, United States
NASA Johnson Space Center, Human Research Program, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
NASA Research Office - Human Research Program (NASA Research-HRP)
Earth Benefits, Space Exploration
ISS Expedition Duration
September 2016 - February 2017; March 2017 - September 2017; -
- In August 2016, replacement of the General Luminaire Assemblies (GLAs) on the International Space Station (ISS) with Solid-State Light Assemblies (SSLAs) begins.
- In addition to removing mercury from the ISS environment and providing more energy-efficient lighting, the SSLAs allow lighting properties (e.g., intensity, spectrum) to be changed to promote alertness and circadian resetting, or to promote sleep, as appropriate.
- Testing Solid State Lighting Countermeasures to Improve Circadian Adaptation, Sleep, and Performance During High Fidelity Analog and Flight Studies for the International Space Station (Lighting Effects) looks at how the introduction of a Dynamic Lighting Schedule (DLS) benefits crew circadian rhythms, sleep, and cognitive performance, as compared to historical data collected under the old GLA lighting.
- The DLS is based on basic and applied work examining the effect of light intensity and spectrum on human circadian rhythms, sleep, and alertness. First, there is a positive dose response between light intensity and the ability of light to reset the circadian clock and promote alertness and performance. Second, short wavelength (blue-appearing) light is most effective at resetting the circadian clock and promoting alertness and performance. Manipulation of light intensity and wavelength can be used to promote better sleep, alertness, and circadian adaptation.
- In addition to providing standard lighting to promote good visual function, the DLS provides advice on when to use two other settings. The pre-bed setting of lower intensity, blue-wavelength-depleted light is intended for use for as long as possible before bed. A higher-intensity blue-light-enriched light setting is intended for use when elevated alertness or circadian adaptation is required.
- The study is designed to generate quantitative data and knowledge for the benefit of crew health, habitability, environment, and human factors in the design of future human space flight vehicles and habitats. The study is also expected to provide guidance for flight surgeons, flight psychologists, and astronauts to help optimize sleep and circadian regulation during space exploration.
- Facilitate circadian adaptation
- Enhance sleep
- Improve alertness and performance, while maintaining high visual acuity and color discernment for operational tasks.
- a General Illumination setting - 4500 K white light, 210 cd
- a Phase Shift/Alertness setting - 6500 K (blue-enriched) white light, 420 cd
- a Pre-Sleep setting - 2700 K (blue-depleted) white light, 90 cd or ideally lower. Further control, based on task or crew member preference, is possible via a dimmer switch or, in Crew Quarters, a shading system.
- Maintains acceptable visual performance and color discrimination for operational tasks
- Improves stability of circadian entrainment
- Improves circadian adaptation following a sleep shift challenge (e.g., a ‘slam-shift’)
- Improves sleep duration and efficiency
- Enhances wake-time alertness and cognitive performance
Spaceflight exposes crew members to sleep and wake schedules that do not follow the course of the sun. This can cause insomnia and fatigue, negatively affecting crew alertness and health. Lighting Effects studies new light sources that can be adjusted for intensity and wavelength across the day, simulating a more regular schedule. Results are expected to provide new information for flight surgeons, psychologists, and crew members to better regulate circadian rhythms and improve sleep. Engineers and designers may also benefit from this information as they build the next generation of crewed space exploration vehicles.
Electric lighting is ubiquitous on Earth and can directly affect alertness. Anyone who uses electric lights can benefit from lights that can be adjusted for intensity and wavelength across the day, improving alertness during waking hours and promoting sleep during evening hours. Millions of people working night shifts would also benefit from a dynamic lighting schedule that mimics natural lighting.
Operational Requirements and Protocols
Decadal Survey Recommendations
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