Sleepless in Space: Study Highlights Sleep Problems Faced by Astronauts

A new study has found that astronauts suffer from chronic sleep deprivation.

The researchers at the Brigham and Women's Hospital (BWH) Division of Sleep and Circadian Disorders, Harvard Medical School and colleagues found that astronauts get around six hours of sleep during training and space flights. Also, several astronauts use sleeping pills, which could affect their performance during an emergency situation.

The study was conducted over a ten-year period and included data from 64 astronauts on 80 Shuttle missions and 21 astronauts on International Space Station (ISS) missions. This is the largest study of its kind, researchers say.

Sleeping in the shuttle or ISS is difficult because the Sun rises every 90 minutes. The several sunrises and sunsets coupled with excitement of being in space and living in closed quarters can severely affect sleep schedules.

"Sleep deficiency is pervasive among crew members," stated Laura K. Barger, PhD, associate physiologist in the BWH Division of Sleep and Circadian Disorders and lead author of the study, according to a news release. "It's clear that more effective measures are needed to promote adequate sleep in crew members, both during training and space flight, as sleep deficiency has been associated with performance decrements in numerous laboratory and field-based studies."

The researchers found that despite NASA's recommendation that astronauts get at least 8.5 hours of sleep per night, crew members in training slept for less than six hours, while those in flight slept for about 6.09 hours on an average.

Another major find of the study was that astronauts were using sleeping pills such as zolpidem and zaleplon. Around 78 percent of shuttle-mission crew members used medication on 52 percent of flights.

Sleep-medication usage during space flights is problematic because research has shown that these drugs affect problem-solving abilities.

"The ability for a crew member to optimally perform if awakened from sleep by an emergency alarm may be jeopardized by the use of sleep-promoting pharmaceuticals," said Barger in a news release.

The researchers said that this study shows that it is important to promote healthy sleeping habits in astronauts. Future missions to Mars or beyond would require people who can cope with living in space for extended periods of time. Some measures such as exposure to specific wavelength of light could help regulate sleep pattern in space.

The study is published in the journal The Lancet Neurology.