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Astronauts have adapted to the challenge of sleeping in space for years. Lessons learned from sleeping in zero gravity will surely one day sleep in space. The first manned mission to Mars will get plenty of rest before exploring the Red Planet.
Replacement crew members have spent an average of six months living and working on the International Space Station for about 23 years, but they suffer from sleep problems just like people on Earth. Some of the challenges are similar to those of shift workers and people with unusual schedules, while others are unique to the space environment.
NASA astronaut Josh Casada is packed into the crew quarters of the International Space Station on March 2.
For example, most people don’t have to worry about floating out of bed due to weightlessness. please do not worry. Astronauts use special restraints to keep them from floating. Pass the space station while you sleep.
The two biggest challenges for astronauts are establishing a sleep environment and a natural sleep cycle.
Dr. Erin Flynn-Evans, director of the NASA Ames Institute’s Fatigue Countermeasures Laboratory, said space stations have private, dark and quiet crew quarters where astronauts can sleep comfortably, but other space missions don’t necessarily. He says that’s not necessarily the case. Center of Mountain View, California.
Like its historic Apollo predecessor, the Orion capsule, which will be used in future Artemis missions to the moon, is a small vehicle with limited space for a crew member and sleeping bags for rest.
“I think of it like camping,” Flynn Evans said. “For a few days, it’s probably not a big deal. But the longer you’re around someone, the more chaos it can cause.”
The space station offers great views of Earth, but the 16 sunrises that astronauts witness each day can wreak havoc on the body’s circadian rhythm, the body’s natural clock for sleep and wakefulness. there is.
On Earth, circadian rhythm disruptions occur in people who work night shifts or experience jet lag while traveling across time zones.
“Light resets our circadian rhythms and regulates our day-night cycles, but in space there are some challenges,” says Flynn-Evans.
The space station orbits the Earth every 90 minutes, creating alternating cycles of darkness and light. Rather than forcing astronauts to adapt to such a bizarre cycle, NASA experts added lighting inside the space station that mimics what people experience on a normal day on Earth. bottom.
“You have to try to block the light from the windows at night,” she said. “And we should try to make the most of either the light from the windows or the interior lighting to ensure that the crew gets synchronized stimulation.” can. ”
Former Japan Aerospace Exploration Agency astronaut Soichi Noguchi is inside the Space Station Sleep Station in April 2021.
Jet lag begins even before the astronauts arrive at the space station, and the astronauts’ sleep schedules change in the days leading up to launch, based on the time and time zone they are launched. Upon arrival at the space station, each astronaut travels to: Greenwich Mean Time“It’s a good middle ground between all participating countries,” said Flynn Evans.
At the Fatigue Countermeasures Institute, Flynn Evans and colleagues are developing tools to help astronauts overcome sleep problems. Strategies include managing when astronauts are exposed to blue light, the primary synchronization wavelength of the circadian system, and when to reduce blue light to aid sleep.
Astronauts have a well-planned schedule, but resupply missions and arrivals of new crew members can disrupt the schedule. Flynn Evans and other researchers have developed approaches to safely alter sleep for astronauts, including deciding when to nap or stay up late to accommodate schedule changes. We are developing.
The same tips that help astronauts sleep apply to Earth. For example, he regularly wakes up and goes to sleep at the same time as much as possible, and before going to bed he limits his exposure to blue light emitted by LED TVs and smartphones. computer and tablet.
Scientists have sleep data from years of spaceflight, but they’re doing simulations. Missions on Earth give you more control.
“We do fake space missions all the time,” said Flynn-Evans. “The Johnson Space Center has a so-called analogue space environment called the Human Exploration Research Analogue (HERA), which is basically a small habitat.”
The CHAPEA crew will live in separate living quarters at NASA’s Johnson Space Center in Houston.
This habitat mimics the size of a lunar base or a small spaceship, and can accommodate a crew of four for extended periods of time. Flynn Evans participated in studies that included: The crew spent 45 days in the habitat, with sleep limited to 5 hours on weekdays and 8 hours on weekends. Participants were tested for attention and performance.
Experiments have shown that if crew members only get five hours of sleep per night, they need more chances to regain sleep on subsequent nights to prevent the negative effects of sleep deprivation. The current requirement is for the crew to get her 8 1/2. NASA says missions get many hours of sleep each night to avoid long-term sleep deprivation, fatigue-related mistakes and health complications.
NASA will begin its first experiment in June, called the “Crew Health and Performance Exploration Analog” (CHAPEA), in a new 3D-printed Mars habitat at the Johnson Space Center.
For one year, a crew of four will live and work in a 1,700-square-foot (158-square-meter) space, simulating life on Mars.focus The first experiment will be nutritional supplementation, but Flynn Evans and fellow researchers will also monitor how well the crew is sleeping.
Using habitats such as HERA and CHAPEA, scientists will be able to understand what would happen in a real mission to the Moon or Mars, such as limited resources, equipment failure, communication problems, and other stressors of small habitats. You can simulate the unexpected.
An unexpectedly rich source of sleep data has proven to be studying the Earth’s limits. Scientists and engineers working on Mars missions such as the Perseverance rover.
A day on Mars is about 39 minutes longer than a day on Earth, but it’s enough that Mars controllers need to make adjustments. Their schedules are always aligned with the Perseverance timetable.
“If you’re on a 39-minute shift, you’re basically going to bed 39 minutes later every day,” said Flynn-Evans. “It doesn’t look too bad overnight. But after five days, he feels like he’s crossed six time zones. It puts a lot of stress on his body.”
There are still many unknowns about being on “Martian time,” including how time-shifting affects the human metabolism.
Understanding how people on Earth have adapted to life on Mars is one way to prepare for future missions to the Red Planet.Flynn Evans and her team are working Work closely with those planning Artemis lunar missions to optimize astronaut schedules, ensure adequate lighting, and reduce noise inside Orion at bedtime.
The researchers also want to study the amount of caffeine astronauts need to wake up so that the crew doesn’t run out of coffee on board spacecraft with limited storage space.
“Sleep is closely linked to performance, alertness, interpersonal communication and relationships, so we want to prepare our crew to be successful and get the sleep they need,” said Flynn Evans. ‘ said.