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Astronauts have been adjusting to the challenges of sleeping in space for years – and their lessons learned from zero gravity will ensure that one day The first crewed missions to Mars would have gotten enough rest before exploring the Red Planet.
Roaming crews have spent an average of six months a year living and working aboard the International Space Station for nearly 23 years, and they struggle with the same sleep problems as people on Earth. Some of the challenges are similar to those of shift workers or those with unusual schedules, but others are more unique to the space environment.
For example, most people don’t worry about floating away from their bed in zero gravity. Don’t worry—astronauts use special restraints to keep them from floating away Through the space station while you sleep.
The two biggest challenges for astronauts include their sleeping environment and establishing a natural sleep cycle.
Astronauts have dark, quiet and private crew quarters on the space station conducive to good sleep — but that won’t always be the case on other space missions, Dr. Erin Flynn-Evans, director of the Fatigue Countermeasures Laboratory at NASA’s Ames Research Center in Mountain View, California.
Like their historic Apollo predecessors, the Orion capsules that will be used during future Artemis missions to the Moon are small vehicles with limited space for the crew and sleeping bags for rest periods.
Flynn-Evans said, “I guess it’s like camping.” “If it’s for a few days, it’s probably not a big deal. But the longer you’re with someone, the more disruptive it can become.
While the space station offers incredible views of Earth, the 16 sunrises an astronaut witnesses in a day can wreak havoc on circadian rhythms, the body’s natural clock for sleeping and waking.
On Earth, disruption of circadian rhythms causes people who work overnight shifts or experience jet lag when traveling across time zones.
“Light is what resets our circadian rhythms and keeps us settled into that day-night cycle, but there are many challenges we face in space,” Flynn-Evans said.
The space station orbits Earth every 90 minutes, creating alternating cycles of darkness and light. Rather than force astronauts to adapt to such a strange cycle, NASA experts have built lighting into the space station’s interior that mimics what people experience during a typical day on Earth.
“We have to try to block light from windows during the night,” she said, “and we really have to try to maximize light through windows or with interior lighting to make sure that The crew is getting synchronizing stimulation so that they are able to stay awake and sleep at the right times.”
Jet lag begins long before astronauts arrive at the space station, and their sleep schedules shift for days prior to liftoff depending on the time of day and time zone from which they will launch. Once they arrive at the space station, each astronaut is transferred Greenwich Mean TimeFlynn-Evans said, “a good middle ground between all the participating countries”.
In the Fatigue Countermeasures Laboratory, Flynn-Evans and his colleagues developed tools to help astronauts overcome sleep challenges. Some strategies include managing when astronauts are exposed to blue light, the primary synchronizing wavelength for the circadian system, and when to reduce blue light to help them sleep.
Astronauts have regular schedules, but they are sometimes interrupted by re-supply missions or the arrival of new crews. Flynn-Evans and other researchers develop approaches for astronauts to safely shift sleep, such as determining when to nap or staying up later to accommodate schedule changes.
The same tips that help astronauts sleep apply on Earth, including following a regular schedule and going to sleep at the same time as possible and limiting blue light exposure before bedtime Which is emitted by LED TV, Smartphone. Computer and tablet.
Although scientists have years of sleep data from simulated conducting spaceflight Missions on Earth allow more control.
“We do simulated space missions all the time,” Flynn-Evans said. “We have an analog space environment at Johnson Space Center called the Human Exploration Research Analog or HERA, and it’s basically a small habitat.”
The habitat mimics the shape of a lunar base or small spacecraft and can house up to four people over long periods of time. Flynn-Evans was involved in a study in which The crew spent 45 days in the habitat and were limited to five hours of sleep on weekdays and eight hours on weekends. Participants were tested for alertness and performance.
The experiment’s findings showed that if crew members got only five hours of sleep a night, they needed more opportunities to make up for it on subsequent nights to prevent the ill effects of sleep deprivation. The current requirement is that crew members get 8½ Hours of sleep per night on a mission to avoid long-term sleep deprivation, fatigue-induced errors and health complications, according to NASA.
In June, NASA will launch the first experiments in a new 3D-printed Martian habitat called the Crew Health and Performance Exploration Analog, or CHAPEA, at the Johnson Space Center.
Over the course of a year, a four-person crew will live and work inside a 1,700-square-foot (158-square-meter) space to simulate living on Mars. focus The first experiment is nutrition, but Flynn-Evans and her fellow researchers will also monitor how well the crew sleeps.
Habitats like HERA and CHAPEA allow scientists to simulate surprises that might occur on real missions to the Moon or Mars, such as limited resources, failed equipment, communication issues and other stresses of small habitats.
Earth-bound study proves unexpectedly rich source of sleep data Scientists and engineers who work on Mars missions such as the Perseverance rover.
A day on Mars lasts about 39 minutes longer than a day on Earth, but that’s just enough that members of Mars Mission Control have to adjust. Persistence in their schedules to stay on the timetable.
“If you’re doing a 39-minute shift a day, that means you’re basically going to bed 39 minutes later every day,” Flynn-Evans said. “It doesn’t feel so bad in a single night. But after five days, it’s like you’ve crossed like six time zones. It’s a real strain on the body.
Many unknowns still exist on “Mars time”, such as how the time change affects the human body’s metabolism.
Understanding how people on Earth adapted to living in Mars times is one way to prepare for future missions to the Red Planet. Flynn-Evans and his team are working Artemis liaises closely with lunar mission planners to optimize the astronauts’ schedules and to ensure that lighting is adequate and noise is reduced inside Orion when sleep is needed.
The researchers also want to study how much caffeine astronauts need for alertness to ensure the crew don’t run out of coffee in spacecraft with limited storage.
“Sleep is closely linked to performance, alertness, interpersonal communication and relationships,” said Flynn-Evans, “so we want to make sure crews are prepared for success and are getting the sleep they need.” Is.