Sleep-Wake Actigraphy and Light Exposure During Spaceflight-Short (Sleep-Short) - 07.29.14

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Sleep-Wake Actigraphy and Light Exposure During Spaceflight-Short (Sleep-Short) examines how space flight affects astronauts’ sleep patterns during Space Shuttle missions. Advancing state-of-the-art technology for monitoring, diagnosing and assessing treatment of sleep patterns is vital to treating insomnia on Earth and in space.

Science Results for Everyone
Information Pending

This content was provided by Charles A. Czeisler, Ph.D., M.D., Laura K. Barger, Ph.D., and is maintained in a database by the ISS Program Science Office.

Experiment Details


Principal Investigator(s)

  • Charles A. Czeisler, Ph.D., M.D., Harvard Medical School, Boston, MA, United States
  • Laura K. Barger, Ph.D., Brigham and Women's Hospital, Boston, MA, United States

  • Co-Investigator(s)/Collaborator(s)
  • Joseph M. Ronda, Harvard Medical School, Boston, MA, United States
  • Kenneth P. Wright Jr., Ph.D., Boulder, CO, United States

  • Developer(s)
    Johnson Space Center, Human Research Program, Houston, TX, United States

    Sponsoring Space Agency
    National Aeronautics and Space Administration (NASA)

    Sponsoring Organization
    Human Exploration and Operations Mission Directorate (HEOMD)

    Research Benefits
    Information Pending

    ISS Expedition Duration
    April 2005 - September 2011

    Expeditions Assigned

    Previous ISS Missions
    Sleep-Short was previously operated on STS-104, STS-109, STS-111, STS-112, STS-113, STS-114, STS-121, STS-115, STS-116, STS-118, STS-120, STS-122, STS-123, STS-124, STS-125, STS-126, STS-127, STS-128, STS-129, STS-130, STS-131, and STS-132.

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    Experiment Description

    Research Overview

    • Previous research conducted on Space Shuttle crewmembers shows that sleep-wake patterns are disrupted on orbit. A wrist-worn Actiwatch records the activity of the crewmembers, and the ambient light they experience.

    • Daily sleep logs are used to evaluate the crewmembers’ subjective evaluation of the amount and quality of their sleep and alertness.

    The success and effectiveness of manned space flight depends on the ability of crewmembers to maintain a high level of cognitive performance and vigilance while operating and monitoring sophisticated instrumentation. During short space flights, crewmembers commonly experience sleep disruption and misalignment of circadian (of or relating to biological processes occurring with cycles of approximately 24 hours) phase. Both of these conditions are associated with insomnia, and impairment of alertness and cognitive performance.

    Relatively, little is known of the prevalence or cause of space flight induced insomnia in short duration missions. This experiment uses state of the art ambulatory technology to monitor sleep-wake activity patterns and light exposure in crewmembers on board the Space Shuttle. Subjects wear a small, lightweight activity and light-recording device (Actiwatch) for the entire duration of their mission. The sleep-wake activity and light exposure patterns obtained in-flight are compared with baseline data collected on Earth before and after space flight. The data collected leads to an understanding of the effects of space flight on sleep; as well as aids in the development of effective countermeasures for short duration space flight.

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    Space Applications
    The information derived from this study will lead to a better understanding of the effects of spaceflight on sleep-wake cycles. The countermeasures that may be developed based on the findings of this study, could improve sleep cycles during missions which in turn will help maintain alertness and lessen fatigue of the Space Shuttle crewmembers.

    Earth Applications
    A better understanding of insomnia is relevant to the millions of people on Earth who suffer nightly from insomnia. The advancement of state of the art technology for monitoring, diagnosing, and assessing treatment effectiveness is vital to the continued treatment of insomnia on Earth. This work has the potential to greatly benefit the health, productivity and safety of groups with a high prevalence of insomnia, such as shift workers and the elderly.

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    Operational Requirements
    Short-duration (Space Shuttle) crewmembers volunteer for the experiment with the goal of obtaining as many volunteers as possible until the Space Shuttle program is retired. Baseline data for each subject is collected for two weeks between Launch minus 120 (L-120) days and L–75; also from L-11 through L-0. Recovery in sleep patterns after space flight is assessed from Return plus 0 (R+0) days through R+7.

    Operational Protocols
    Crewmembers put on Actiwatches as soon as possible upon entry into orbit (FD1) and wear the Actiwatches continuously throughout the flight. Sleep logs are completed each day within 15 minutes of awakening. On the last day of the mission, crewmembers remove and stow the Actiwatches.

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    Results/More Information
    Data collection for this investigation is ongoing. Final results will be analyzed for completion of data collection from the last test subject. (Evans et al. 2009)

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    Results Publications

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    Ground Based Results Publications

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    ISS Patents

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    Related Publications

      Monk TH, Buysse DJ, Billy BD.  Using daily 30-min phase advances to achieve a 6-hour advance: Circadian rhythm, sleep, and alertness. Aviation, Space, and Environmental Medicine. 2006 Jul; 77(7): 677-686. PMID: 16856351.

      Mallis MM, DeRoshia CW.  Circadian Rhythms, Sleep, and Performance in Space. Aviation, Space, and Environmental Medicine. 2005; 76(6 Suppl): B94-107.

      Dijk D, Neri DF, Wyatt JK, Ronda JM, Riel E, Ritz-De Cecco A, Hughes RJ, Elliott AR, Prisk GK, West JB, Czeisler CA.  Sleep, performance, circadian rhythms, and light-dark cycles during two space shuttle flights. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology. 2001; 281(5): R1647-1664. PMID: 11641138.

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    Related Websites
    Sleep Medicine at Harvard Medical School
    International Space Station Medical Project (ISSMP)

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    image This image shows an Actiwatch Activity Monitor next to a ruler to demonstrate the size of the Actiwatch. Image courtesy of NASA, Johnson Space Center.
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    image NASA Image: S104E5114 - Astronaut, Janet Kavandi on STS-104 wearing an Actiwatch on her right wrist for recording activities.
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