Sleep in space

[4] Astronauts and ground crews frequently suffer from the effects of sleep deprivation and circadian rhythm disruption.

During the Apollo program, it was discovered that adequate sleep in the small volumes available in the command module and Lunar Module was most easily achieved if (1) there was minimum disruption to the pre-flight circadian rhythm of the crew members; (2) all crew members in the spacecraft slept at the same time; (3) crew members were able to doff their suits before sleeping; (4) work schedules were organized – and revised as needed – to provide an undisturbed (radio quiet) 6-8 hour rest period during each 24-hour period; (5) in zero-g, loose restraints were provided to keep the crewmen from drifting; (6) on the lunar surface, a hammock or other form of bed was provided; (7) there was an adequate combination of cabin temperature and sleepwear for comfort; (8) the crew could dim instrument lights and either cover their eyes or exclude sunlight from the cabin; and (9) equipment such as pumps were adequately muffled.

[12] Studies from the medical and aviation industries have shown that increased and intense workloads combined with disturbed sleep and fatigue can lead to significant health issues and performance errors.

[13] Research suggests that astronauts' quality and quantity of sleep while in space is markedly reduced than while on Earth.

Current space flight data shows that accuracy, response time and recall tasks are all affected by sleep loss, work overload, fatigue and circadian desynchronization.

The effects of work-rest schedules, environmental conditions and flight rules and requirements on sleep, fatigue and performance are also being evaluated.

Since the ISS orbits the Earth every 1.5 hours, the flight crew experiences 16 sunrises and sunsets per day.

The stable, trait-like (phenotypic) inter-individual differences observed in response to sleep loss point to an underlying genetic component.

[15] This article incorporates public domain material from Human Health and Performance Risks of Space Exploration Missions (PDF).

An astronaut asleep in the microgravity of Earth orbit-continual free-fall around the Earth, inside the pressurized module Harmony node of the International Space Station in 2007
Mission Specialist Margaret Rhea Seddon , wearing a blindfold, sleeps in SLS-1 module ( STS-40 )
Flight engineer Nikolai Budarin , uses a computer in a sleep station in the Zvezda Service Module on the International Space Station.
A man, dressed in blue work clothing, seen in a small cubicle.
Cosmonaut Yury Usachov in his sleeping compartment on Mir, called a Kayutka