The recently-released results of a study carried out by researchers from the Brigham and Women's Hospital, Harvard Medical School, Boston, and the University of Colorado have revealed the extent of the sleep deprivation suffered by astronauts over the course of a long-term mission in Earth-orbit. This study and others like it are the result of an increasing effort undertaken by agencies around the world to study the physiological and psychological impacts of a permanent human presence in space.

Most ordinary people will experience some sleep-related deficiency at some point in their lives. Such conditions can be brought on by physical discomfort, stress, or environmental factors such as lighting. As you can imagine, the environment experienced by astronauts during a long-term stay in Earth-orbit fosters these conditions perfectly, causing many astronauts to suffer more than their Earth-bound counterparts.

The issue of sleep deprivation in astronauts is not a new problem, and has been documented since the very early days of space exploration. But with agencies around the world looking deeper into space and planning ever more ambitious long-duration missions, human frailty has become one of the key blocks to our ever-growing aspirations. In order to progress with these endeavors, we must better understand the causes and effects of sleep deprivation and how to combat them, as a drop in concentration or focus due to fatigue could prove to be fatal in deep space.

Through research conducted both on Earth and in space, scientists are attempting to combat sleeping deficiencies, and it is hoped that the results of the study will better inform these efforts. The research involved an observation of the sleep patterns of 64 astronauts over the course of 80 space shuttle missions, and 21 further astronauts during their tenure aboard the ISS.

Cosmonaut Nikolai M. Budarin, working in his sleep station in the Zvezda Service Module aboard the ISS (Photo: NASA)

On average, astronauts involved in the study were scheduled to take 8.5 hours of sleep each day. However, the study discovered that most astronauts only managed to rest 6 hours per day. One of the unwanted side effects of this was that 78 percent of shuttle mission members used sleep-promoting drugs for roughly half of the days they were in orbit, with 75 percent of ISS crew members also reporting use of the drugs.

"The study provided us valuable data and insights into incidence and severity of sleep deficiencies in space and has driven the development of countermeasure approaches that are already being tested aboard the space station," states Bill Paloski, manager of NASA's Human Research Program. "We have similar studies in progress and plan to address multiple other risk areas aboard the space station, and we expect to fully utilize that valuable platform in this endeavor for as long as it remains aloft."

Whilst currently no one factor can be isolated to explain the sleep deprivation suffered by astronauts, it is currently believed that disruptions to a body's circadian rhythm coupled with the intense stress and general uncomfortable nature of life in space is to blame for the deficiency. The results of the study serve to highlight the magnitude of the issue posed to astronauts on long-term missions, and emphasizes the vital nature of projects aiming to combat the issue.

Those wishing to view the results of the study may do so online, where it has been published in the Lancet Neurology journal.

Source: NASA

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