How do astronauts sleep in space?
Astronauts sleep in small private sleeping quarters, zipped into sleeping bags attached to the wall so they do not float around. In microgravity, there is no up or down, so they can sleep in any position.
On the International Space Station, each crew member has a phone-booth-sized cabin with a sleeping bag, a laptop and space for personal items. The sleeping bag is fastened to the wall, and some astronauts use a strap or pillow to keep their head from drifting. Good air flow is important, because exhaled carbon dioxide can collect around a sleeper's face without gravity to move it.
Astronauts usually schedule about eight and a half hours for sleep. With 16 sunrises each day, they cannot rely on the Sun to set their body clocks. The ISS uses special lighting that changes color through the day to help them stay on a regular schedule.
Sleep challenges
Many astronauts find it hard to sleep well in space because of noise from fans and machines, excitement, stress and changes in their body clock. Some use eye masks and earplugs. Astronauts have reported that their arms float in front of them while they sleep unless they tuck them in.
Did You Know?
Some astronauts report vivid dreams in space and even seeing flashes of light with their eyes closed, caused by cosmic rays passing through their eyes.