Sleeping in zero gravity is a challenge. Far away from home, unfamiliar environment, weightlessness and shorter days all make sleeping in space a real challenge. No wonder sleeping pills are the main medication used by astronauts.
How do astronauts sleep?
Inner compartments of a space station are pressurized. The pressure resembles Earth's atmospheric pressure at sea level. The air composition matches closely to our own atmosphere. But one thing that puts a spin into everything is zero gravity in space.
The weightlessness means astronauts can never sleep in a bed surrounded by pillows. All of it will soon drift away, colliding with each other. So instead, astronauts sleep in sleeping bags tethered to the walls. Even the pillows are strapped onto their heads!
Challenges of sleeping in space
- Circadian rhythm disturbances: Astronauts undergo vigorous training leading up to their missions. So when they do, they hardly have time to adjust to the new routine.
- Shorter days and nights: Astronauts aboard the International Space Station orbit the earth every 90 minutes. This means they experience 16 sunrises and sunsets everyday. So they work to a 24 hour day set at Greenwich Mean Time (GMT).
- Noisy environment: You may not have any neighbours, but a space station is a noisy place. Astronauts often wear ear plugs to clog out noise when sleeping.
Research on sleeping in space
Studies show that astronauts sleep better when they are in space. But these studies were done on a limited number of astronauts for shorter duration. In one study the sleep apnoea reduced by 55 percent when they were in space, compared to sleeping back on Earth. Snoring also is known to reduce dramatically under zero gravity.
A large scale study by NASA is now underway. The results are yet to be published. This study known as Sleep-Long will help future astronauts who will engage in longer duration space explorations, to find out the effect of weightlessness and altered night and day on sleep. It can also benefit sleep research back on earth.