To develop measures to improve the quality and duration of sleep in space, scientists are conducting the Sleep — Wake Actigraphy and Light Exposure During Spaceflight — Long investigation or Sleep-Long. This study examines the sleep — wake patterns of the crew members while they are aboard the space station.
The quality and duration of slumber impact human health, attitude, and ability to focus. The Institute of Medicine released a report in 2006 stating that chronic sleep loss could lead to hypertension, diabetes, obesity, cardiovascular disease, stroke and multiple psychiatric disorders. Crew members spend years training for missions on strenuous schedules and then, when they finally reach the space station, their coordinated timetable does not allow for hitting the snooze button.
The Sleep — Long investigation uses an objective approach to monitoring sleep by having the crew wear an Actiwatch. This device, which resembles a wristwatch, monitors sleep/wake activity using a miniature accelerometer that records crew movement. The Actiwatch also measures the ambient light conditions during the study. There is a subjective element to the investigation, as well, in which the crew maintains a daily sleep log for the duration of one week, every third week while aboard the space station.
Scientists compare sleep-wake activity and light exposure patterns from the data obtained in orbit with the baseline data collected on Earth. Results from the investigation may lead to changes in lighting requirements, sleep shifting schedules and workload plans for future space station occupants.
The study may also help to indicate when additional measures are needed to minimize the risks of sleep deprivation in orbit. Findings from the study will not only benefit the crew of the space station for the immediate future, but also have important implications for future long-duration exploration. Such findings may also provide improved sleep aids for those suffering from insomnia here on Earth, as well as benefit shift workers, such as hospital, law enforcement, and military staff.
Read Complete Article By by Jessica Nimon, NASA’s Johnson Space Center