Astronauts sleeping. Image: Wikimedia
Being an astronaut turns out to be a pretty gruelling career choice. On top of the weight loss, vestibular dysfunction, anaemia, cardiovascular deconditioning, muscle atrophy and bone loss due to the lack of gravity, a new 10-year study on astronauts' sleeping habits has just come out. The verdict? Astronauts are popping pills to ward off sleep deficiency.The study, conducted by researchers from Brigham and Women's Hospital Division of Sleep and Circadian Disorders, Harvard Medical School, and the University of Colorado, and published in The Lancet, found that most astronauts have problems getting a good night's rest. In the largest ever study of sleep during space flight, they recorded 4,000 nights of sleep on earth and 4,200 in space from 85 astronauts.
NASA schedules 8.5 hours of sleep each night for an astronaut but, on average, they're getting about six. The worry is that crew members will be unable to perform as well if they don't get a good night's sleep. It's been suggested that sleep deprivation leads to more emotional instability, a reduction in creativity, response speeds, attention, alertness and many other things which would be of use while in space.It's easy to imagine why astronauts might have difficulty getting to sleep. For example, weightlessness can disrupt the proprioceptive system, which helps you orient your limbs in relation to one another. One Apollo Astronaut previously reported that, "The first night in space when I was drifting off to sleep. I suddenly realized that I had lost track of … my arms and legs. For all my mind could tell, my limbs were not there."Then there's the fact the International Space Station is positioned so that it experiences a sunrise and sunset 15 to 16 times a day.A previous sleep study by the European Space Agency and the Russian Institute for Biomedical Problems that used a simulated space environment found some of its astronauts became sleep-deprived while others slept more and more, almost going into a kind of hibernation, when they were deprived of the usual night-day pattern.But this new study also found that even before they've left earth, three months prior to launch, astronauts only average 6.5 hours of sleep a night.The counter to this lack of sleep is medication. The researchers reported that over 75 percent of astronauts took pills like zolpidem (Ambien) to help. Shuttle-mission crew members took them for over half of their nights in space.Laura K. Barger, PhD, associate physiologist in the BWH Division of Sleep and Circadian Disorders and lead study author, said in a statement that, "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."She added that, "Routine use of such medications by crew members operating spacecraft are of particular concern, given the US 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. This consideration is especially important because all crew members on a given mission may be under the influence of a sleep promoting medication at the same time."