Astronauts May be Sleep-Deprived During Space Flight Missions

People on Earth aren't the only ones that sometimes have trouble sleeping. Scientists have found that astronauts can suffer considerable sleep deficiency in the weeks leading up to and during space flight. In fact, they found that there's a widespread use of sleeping medication among astronauts.

The extensive study recorded more than 4,000 nights of sleep on Earth in addition to more than 4,200 nights in space, using data from 64 astronauts on 80 Shuttle missions and 21 astronauts aboard the International Space Station (ISS) missions.

"Sleep deficiency is pervasive among crew members," said Laura Barger, the lead author of the new study, in 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."

NASA actually schedules 8.5 hours of sleep per night for crew members in space flight. Yet on average, the researchers found that the average duration of sleep was just under six hours on shuttle missions and just over six hours on ISS missions. Not only that, but just 12 percent of sleep episodes on shuttle missions and 24 percent on ISS missions lasted seven hours or more. That's compared with 42 percent and 50 percent, respectively, in a post-flight data collection interval when most astronauts slept at home.

That's not all that the researchers found, though. There was also a widespread use of sleeping medications among astronauts during space flight. In fact, three-quarters of ISS crew members reported taking sleep medication at some point during their time on the space station.

"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. "Routine use of such medications by crew members operating spacecraft are of particular concern, given the U.S. Federal Drug Administration (FDA) warning that patients using sleeping pills should be cautioned against engaging in hazardous occupations requiring complete mental alertness or motor coordination, including potential impairment of performance of such activities that may occur the day following ingestion of sedative/hypnotics."

The findings reveal the importance of finding better methods to promote sleep during spaceflight. This is particularly crucial if future human exploration missions are to occur.

The findings are published in the journal The Lancet Neurology.