Sleeping in Space

Sleeping in microgravity can be challenging! In the weightless environment of the International Space Station (ISS), astronauts cannot "lie down" to sleep: there is no real "up" or "down."

Sleeping in Space

It's bedtime for Chris Hadfield. Watch the video to learn all about his bedtime routine and check out his pyjamas. (Credits: Canadian Space Agency, NASA)

Sleeping quarters in space

In the weightless environment of space, the carbon dioxide (CO2) that astronauts expel could form a bubble around their head. That is why they have to sleep near an air vent.

Astronauts go to bed in their "sleep stations," personal sleep compartments the size of a telephone booth, which have:

  • a sleeping bag
  • a pillow
  • a lamp
  • an air vent
  • a personal laptop
  • a place for personal belongings

Crew members who want to sleep outside the sleep compartments can secure their sleeping bag to the floor, the ceiling or the wall. They generally use earplugs and a sleep mask to block out the noise and light.

Sleeping vertically

In space, sleeping on the floor is just as comfortable as sleeping on the wall: there is no difference in the weightless environment.

However, since astronauts are used to sleeping on a mattress on Earth, their sleeping bag has a rigid cushion, to exert pressure on their back.

JAXA astronaut Koichi Wakata sleeping comfortably attached to the wall of the Kibo laboratory on the ISS. (Credit: NASA)

Even though astronauts are allotted about 8.5 hours for sleep every day, many of them have reported needing only about 6 hours to feel fully rested. Some specialists believe that this is because the body tires less quickly in weightlessness: the muscles don't have to work as hard as on Earth.

However, the noise level on the ISS creates poor conditions for getting a good night's rest. That is why astronauts usually wear earplugs while they sleep.

Snoozing… day and night

After long-duration stays in space, some astronauts have reported the sensation of floating over their mattress for a few days after their return to Earth.

While orbiting the Earth, astronauts witness 16 sunrises and sunsets every 24 hours.

While seeing a sunrise every 90 minutes may seem like an incredible experience, it can also make it difficult for astronauts to maintain a regular sleep pattern

Luckily, astronauts use Greenwich Mean Time (GMT) to keep a regular schedule. This time zone represents a compromise between the mission control centres in Houston and Moscow.

Explore further