Monday, August 11, 2014

Fwd: Astronaut performance jeopardized by sleep deprivation



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Begin forwarded message:

From: "Gary Johnson" <gjohnson144@comcast.net>
Date: August 11, 2014 10:59:08 AM CDT
To: "Gary Johnson" <gjohnson144@comcast.net>
Subject: FW: Astronaut performance jeopardized by sleep deprivation

 

Ars Technica 

Astronaut performance jeopardized by sleep deprivation

Astronauts working on ISS missions sleep just over six hours a night.

by Katie Collins Aug 9, 2014 12:00 pm UTC

Ever since the Apollo 11 headed to the Moon in late 1969, astronauts have complained of sleep deprivation. Now a study has shed light on the extent of the sleep deprivation and fatigue suffered by those who travel into space.

In accordance with official NASA flight schedules, astronauts are ordered to get 8.5 hours of sleep every night. But after tracking the sleep patterns of 85 crew members aboard the International Space Station (ISS) and space shuttles, researchers have discovered that astronauts on shuttle missions sleep for under six hours per night on average and just over six on ISS missions.

Crew members on modern space missions sleep in quiet, darkened chambers and three quarters of astronauts take sedatives—yet the problem still prevails. It was not only that astronauts failed to get the required amount of sleep, however. In the three-month pre-flight training period, sleep was also found to be significantly disturbed. During this time crew began to build up a long-term sleep deficiency, averaging less than 6.5 hours while in training.

The number of astronauts taking sleep medication has also been highlighted as a particular concern, after the study discovered that three quarters of ISS crew take sleep medication at least once during their stay and that 78 percent of shuttle crew members used medication on more than half of their nights in space.

"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," warned Laura K Barger from Brigham and Women's Hospital, who is lead study author. Taking sedatives and hypnotics has also widely been found to impair performance and physical activities, which is why many such medications carry warnings against operating heavy machinery or vehicles after ingestion.

The ten-year study has seen more than 4,000 nights of astronauts' sleep on Earth and over 4,200 nights of sleep in space be recorded, and has concluded that more action needs to be taken to help optimise performance of astronauts.

"Because chronic sleep loss leads to performance decrements, our findings emphasise the need for development of effective countermeasures to promote sleep," write the authors in the study's abstract.

Sleep deprivation has been found to be highly detrimental to an astronaut's performance both during training and space flight. Closer to Earth, around 15-20 percent of fatal airline crashes caused by human error are thought to be a direct result of pilot fatigue. There is no consensus yet on what countermeasures should be implemented, but they could include scheduling modifications and the teaching of behavioural strategies.

 

 

© 2014 Condé Nast. All rights reserved

 

 

 

 

Nasa reveals astronauts suffer from 'chronic sleep loss' and are over-dependent on sedatives

More than three-quarters of astronauts in the study used sleeping pills in more than half of the nights spent in space

Monday 11 August 2014

 

A new report into the sleeping habits of astronauts has revealed that when it comes to getting some shut eye, even the peace and quiet of space doesn't help.

Astronauts commonly suffer from sleep deprivation according to the 10-year study published in The Lancet, with crew members aboard the now-retired space shuttle sleeping for less than six hours a night on average while those crewing the International Space Station (ISS) managed just over six hours of kip.

This is far less than 8.5 hours of sleep that Nasa orders astronauts to get every night and less than the average of six and a half hours achieved by UK and US sleepers.

The study, which used a special wrist watch to study the sleeping habits of 85 different crew members between 2001 and 2011, also highlighted a worrying dependence on sleeping pills, with more than the three-quarters of astronauts using sedatives such as Ambien on more than half their nights in space.

"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," wrote lead author Laura Barger of Brigham and Women's Hospital at the Harvard Medical School.

The sleeping troubles didn't just happen in space either. As well as studying 4,200 nights of sleep off-Earth, the study looked at 4,000 nights of sleep at home, finding that even during the astronaut's three month pre-flight training period they averaged only 6.5 hours of sleep.

"Because chronic sleep loss leads to performance decrements, our findings emphasise the need for development of effective countermeasures to promote sleep," wrote the authors in the paper's abstract.

For astronauts on board the ISS there's no such thing as a 'natural' sleeping pattern, with the station running on Coordinate Universal Time (the same as GMT) but with the sun rising and setting every 90 minutes.

Crew members bunk down in dedicated 'sleep stations' where they climb into sleeping bags tied to a wall. The lack of gravity means they don't have to worry about a pillow to support their neck but the study suggested that extra measures (such as the exposure to specific wavelengths of light) might be necessary to ensure astronauts can say 'Goodnight Earth' and mean it.  

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