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BEDBOUND CAPTAIN: Wearing a virtual reality headset, a study participant tries to dock a virtual spacecraft.

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Would You Spend Two Months in Bed for Science?

Scientists study people in bed on Earth to learn how to keep astronauts healthy in space

AS YOU READ, THINK ABOUT what effects living in space might have on the human body.

Does two months of lounging around with unlimited TV, video games, catered food, and no chores sound like fun? It might to a lot of people. And that’s exactly what the German Aerospace Center is asking members of the public to do as part of a new study. Participants will even get paid $18,500 for the effort. But here’s the catch: For the entire 60 days, volunteers have to stay reclined in bed. They can’t get up—for any reason.

Everyone in the bedrest study will have to do everything lying down: change clothes, bathe, and even use the bathroom. At the same time, researchers will be poking them with needles and running daily medical tests. Each day, the scientists will also place some of the subjects in a giant spinning machine called a centrifuge.

Picture yourself lying around for two months with all the TV and video games you want. People bring you food, and you have no chores. Does that sound like fun? It might to many people. The German Aerospace Center is asking members of the public to do just that. It’s all part of a new study. Volunteers will even get paid $18,500. But there’s a catch. For the entire 60 days, they have to lie in bed. They can’t get up—for any reason.

Everyone in the bedrest study will do everything lying down. That includes changing clothes, bathing, and even using the bathroom. And researchers will be poking them with needles and running daily medical tests. Each day, the scientists will also place some of the subjects in a centrifuge. That’s a giant spinning machine.

NASA

SPACE WALK: Astronaut Bruce McCandless II, floats in space a few meters from the space shuttle in 1984.

The study is designed to re-create some of the effects caused by extended periods of weightlessness in space. Astronauts aboard the International Space Station (ISS), orbiting high above Earth, work in microgravity. They experience a weaker downward force of gravity than that felt on Earth, which causes them to float. Because astronauts in space aren’t moving around as they normally would, they can develop health problems. People lying in bed for months can have the same problems. A centrifuge, though, can mimic gravity’s pull and possibly prevent these issues (see How a Centrifuge Works).

The German Aerospace Center is collaborating with NASA and the European Space Agency on this analog study. It’s just one of many such studies being carried out in different settings on Earth to simulate environments in space (see 4 More Analog Missions). What scientists learn from this research could help them find better ways to keep astronauts healthy during long spaceflights. “This will be especially important as we move from the International Space Station, where missions last between six months to a year, to longer-duration explorations, such as a Mars mission, which could take up to three years,” explains Brandon Vessey, an analog mission scientist at NASA.

Astronauts in space are weightless for long periods. The study is designed to re-create some of the effects of those conditions. On the International Space Station (ISS), high above Earth, astronauts work in microgravity. They feel a weaker downward force of gravity than on Earth. That allows them to float. In space, astronauts aren’t moving around as they normally would, so they can develop health problems. People lying in bed for months can have the same problems. But a centrifuge can imitate gravity’s pull, and it might prevent these effects.

The German Aerospace Center is working with NASA and the European Space Agency on this analog study. It’s just one of many studies like it. Analog studies take place in different settings on Earth to imitate environments in space. Scientists are looking for better ways to keep astronauts healthy during long spaceflights. The results of this research could help them. “This will be especially important as we move from the International Space Station, where missions last between six months to a year, to longer-duration explorations, such as a Mars mission, which could take up to three years,” explains Brandon Vessey. He’s an analog mission scientist at NASA.

GRAVITY’S PULL

On Earth, people’s bodies have to support their weight—a combination of their mass and gravity’s pull. All movement, no matter how small, requires the body to work against this force. That exercises muscles and bones, keeping them strong and healthy. But astronauts in microgravity, who are weightless, and people on bedrest, who aren’t moving, no longer get this constant mini workout. “As a result, their muscles and bones begin to atrophy, or waste away,” says Edwin Mulder, a physiologist who studies how the human body works. He’s leading the bedrest study at the German Aerospace Center’s Institute of Aerospace Medicine.

Currently, astronauts aboard the ISS counteract the impact of microgravity on their bodies by exercising. They train on stationary bicycles and treadmills and do weight-resistance for up to two-and-a-half hours each day. It’s important for them to stay fit so they can do their work.

Weight is a combination of mass and gravity’s pull. On Earth, people’s bodies have to support their weight. The body must work against this force for all movement, no matter how small. That exercises muscles and bones, keeping them strong and healthy. But astronauts in microgravity are weightless, so they don’t get this constant mini workout. Neither do people on bedrest, who aren’t moving. “As a result, their muscles and bones begin to atrophy, or waste away,” says Edwin Mulder. As a physiologist, he studies how the human body works. He’s leading the bedrest study at the German Aerospace Center’s Institute of Aerospace Medicine.

Astronauts on the ISS fight the effects of microgravity on their bodies. Today, they do this by exercising for up to two-and-a-half hours each day. They use exercise bicycles and treadmills and do weight-resistance. They need to stay fit so they can do their work.

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TEST RIDE: A dummy goes for a spin in a centrifuge, which whirls people around to mimic gravity.

In microgravity, the fluids in astronauts’ bodies shift toward their heads. “When you’re on Earth, your blood and all of your other fluids are being pulled toward the ground by gravity,” says Vessey. “When you enter microgravity, you no longer have gravity pulling fluids down.” To re-create the way fluids in the body move in microgravity, bedrest volunteers will lie with their heads tilted back 6 degrees. “This lets us study the effect of this upward fluid shift on things like the heart, brain, and eyes,” says Vessey. This shift can cause astronauts’ faces to look swollen in space and may result in vision problems that persist even after they return to Earth.

In microgravity, the fluids in astronauts’ bodies move toward their heads. “When you’re on Earth, your blood and all of your other fluids are being pulled toward the ground by gravity,” says Vessey. “When you enter microgravity, you no longer have gravity pulling fluids down.”

Bedrest volunteers will lie with their heads tilted back 6 degrees. That will re-create the movement of the body’s fluids in microgravity. “This lets us study the effect of this upward fluid shift on things like the heart, brain, and eyes,” says Vessey. This shift can make astronauts’ faces look swollen in space. It may also cause vision problems that last even after they return to Earth.

GOING FOR A SPIN

The lack of movement and the tilted position should cause bedrest subjects to experience health issues similar to those of astronauts in microgravity. The other component of the study is testing a way for possibly reducing these negative effects. Scientists will spin two-thirds of the study participants in a centrifuge large enough for a person for 30 minutes a day. The outward force generated by the machine will equal the pull of gravity on Earth. Researchers want to see whether that could help reduce bone and muscle loss, as well as shift bodily fluids back toward volunteers’ feet.

The lack of movement and the tilt should cause health effects in bedrest subjects. These effects should be like those on astronauts in microgravity. But the study has another part. It will test a possible way to reduce these harmful effects. Scientists will use a centrifuge large enough for a person. Each day, they’ll spin two-thirds of the study subjects inside it for 30 minutes. The machine will create an outward force equal to the pull of gravity on Earth. Could that help reduce bone and muscle loss? And could it shift bodily fluids back toward volunteers’ feet? Researchers want to see.

The study could influence the design of future spacecraft. “People have long assumed that a spinning spacecraft would provide the best artificial gravity solution to providing an Earth-like environment in space,” says Jennifer Ngo-Anh. She directs the human and robotic exploration program at the European Space Agency. But building a whole spacecraft that rotates might be impractical, she says. Instead, having a centrifuge, like the one being used in the bedrest study, onboard a spacecraft might be a better option.

The study could also affect the design of future spacecraft. “People have long assumed that a spinning spacecraft would provide the best artificial gravity solution to providing an Earth-like environment in space,” says Jennifer Ngo-Anh. She directs the human and robotic exploration program at the European Space Agency. But building a whole spacecraft that spins might be difficult, she says. Instead, the spacecraft could have a centrifuge, like the one in the bedrest study. That might work better.

PREPARING FOR THE FUTURE

Analog studies help scientists learn not only how to combat the physical challenges of living in space, but also how space travel might affect astronauts’ mental health. For example, researchers might have volunteers live in a replica space habitat to see how well they handle working together in a cramped space over time.

Analog studies teach scientists how to overcome the physical problems of living in space. But they also show how space travel might affect astronauts’ mental health. For example, volunteers might live in a model of a space habitat. Researchers will study how they handle working together in this small space over time.