Sleepless in Space: Astronauts Find Sleep Elusive


If you ever take a trip to outer space, you may want to bring a sleep mask. A new report shows that astronauts often face sleep deprivation, fatigue and off-kilter circadian rhythms.

Perhaps that shouldn’t come as a surprise, given the fact that the astronauts are orbiting Earth at about 17,000 miles per hour and normal cues for the sleep-and-wake cycle, such as the sunrise, are not the same as at home. In fact, the orbiting astronauts have a far different experience with the sun – for them, it rises and falls every 90 minutes.

November 2, 2007 – European Space Agency (ESA) astronaut Paolo Nespoli, STS-120 mission specialist, rests in his sleeping bag in the Harmony node of the International Space Station while Space Shuttle Discovery is docked with the station. Image/Caption credit: NASA

“It’s far too fast for the body clock to adapt to, and so they essentially experience a perpetual jet lag,” Erin Flynn-Evans, director of NASA’s Fatigue Countermeasures Laboratory, told CNN Health.

Previous research has found that astronauts aboard the International Space Station are routinely affected by chronic sleep loss, with an average sleeping time of about six hours. That’s with the help of sleep-inducing medicine, too. About 75 percent of crew members reported taking a sleep aid, according to a 2014 study.

Even the first visitors to the moon, Neil Armstrong and Buzz Aldrin, reported challenges with sleeping during their maiden voyage.

Related: Sleep Disruptions Can Wipe Away Memories

While other jobs that include nights shifts, such as working in a hospital or flying a plane, can lead to functional impairments, sleep deprivation among astronauts comes with an extra dose of concern.

“When you’re in space, the stakes are much higher,” Flynn-Evans told CNN. “A missed keystroke can be the difference between life and death, really.”

High-Stakes Sleeping

When in space, astronauts are more likely to fall into a different sleep cycle than the one they’re accustomed to on Earth, said NASA experts. Instead of being locked into a 24-hour cycle, astronauts tend to revolve around a cycle about one-fifth longer, or 12 minutes.

“That extra 12 minutes doesn’t seem like a lot, but … after a couple of weeks, you’re going to be falling asleep several hours later than you did the first day,” Flynn-Evans told CNN Health.

But the changes in sleep patterns and the solitary environment don’t affect every person the same way. A previous study assessing how six crew members adapted to the rigors of outer space found divergent psychological and behavioral results. The simulated mission found that one crew member developed “persistent sleep onset insomnia” while two others experienced “altered” sleep-wake cycles.

Related: This Sleep Mask Wakes You Up With a Sunrise

But “two crew members showed neither behavioral disturbances nor reports of psychological distress” during the 17-month simulated test, which confined the crew members to a small chamber and had them endure the daily tasks of a mission to Mars.

The study suggests that some people are better equipped to handle the challenges of a space mission – from sleep deprivation and fatigue to stress and near-solitary confinement – than others.

“These results highlight the importance of identifying behavioral, psychological, and biological markers of characteristics that predispose prospective crewmembers to both effective and ineffective behavioral reactions during the confinement of prolonged spaceflight,” write the study authors.