#astronaut problems

A new study by Harvard Medical School has found many astronauts suffer serious levels of sleep deprivation that could be putting their lives in danger.

Scientists studied the sleep patterns of 64 astronauts on 80 space shuttle missions and 21 International Space Station (ISS) crew members before, during and after spaceflight.

They found that on average astronauts snatch less than six hours sleep on orbiting space shuttles and just over six hours on ISS missions.

This was despite the American space agency Nasa scheduling 8.5 hours of sleep per night for space-travelling astronauts.

Around three-quarters of astronauts also resorted to sleeping pills during spaceflight, raising concerns about the effect the drugs may be having on their performance.

She added: “The ability for a crew member to optimally perform if awakened from sleep by an emergency alarm may be jeopardised by the use of sleep-promoting pharmaceuticals. Routine use of such medications by crew members operating spacecraft is of particular concern.”

"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," she said. "In fact, on the four shuttle missions on which all crew members participated, all crew members reported taking sleep-medications on the same night 6% of the time."

With the sun rising and setting every 90 minutes, Earth orbit is known to be non-conducive to sleep.

The Apollo astronauts who flew to the moon in the early 1970s complained that their sleep was interrupted by light, noise and the cooling systems in space suits.

But sleep disturbance continues to affect astronauts despite the quiet and dark “sleep stations” installed on the ISS, leading some scientists to speculate that microgravity itself may be to blame.

Co-author Dr Charles Czeisler, also from Harvard Medical School, said: “Future exploration spaceflight missions to the moon, Mars, or beyond will require more effective countermeasures to optimise human performance by promoting sleep during spaceflight.

"These may include modifications to schedules, strategically timed exposure to specific wavelengths of light, and behavioural strategies to ensure adequate sleep, which is essential for maintaining health, performance and safety."

"Only four people have consecutively lived and worked for more than one year in space," he said. "As such, how sleep and behavioural health will be affected during space exploration is poorly understood.