Why Would We Need Artificial Gravity in Space?

the Earth. If you're like many people, your most dramatic experience with this type of spinning forces probably from an amusement park ride, maybe the classic rotor ride that has produced a great deal of joy and yes, vomit since the middle of the eight hundreds, But a handful of people, including astronauts and military pilots, experience the same phenomenon in a human rated centrifuge, which is a machine that spins to produce these high G forces, which can be summarized

as forces that cause the perception of weight like acceleration, deceleration and quick shifts and direction like on a roller coaster, aboard high performance aircraft during high speed turns, during launches into space, and when spacecraft's rapidly slow as they re enter Earth's atmosphere, and like in these rotating machines, in a very real sense, this type of rotation produces gravity,

artificial gravity to be precise. It provides weight to your body, a weight that your bones and muscles can't distinguish from the weight that Earth or another planet provides on account of its sheer mass. Consequently, for decades, science fiction writers have envisioned rotating spaceships that create artificial gravity for astronauts

during the longest phases of space missions. These phases are when they are not extra heavy due to the ship accelerating to build up speed or decelerating in the atmosphere, but when they feel relatively weightless due to the craft coasting, negating the effects of gravity. Two examples of such artificial gravity and science fiction are the film The Martian and the nineteen sixty eight film two thousand one, a Space Odyssey.

The Martian features an interplanetary craft, the Hermes, with a large wheel shaped section that rotates on its journey between Earth and Mars, and you notice that up for the astronauts inside the Hermes is always towards the center of the wheel. While down or the floor is the outer rim of the wheel. In two thousand one, a Space Odyssey space station five is a spinning station that generates

artificial gravity equal to that of the Moon's gravity. Apart from mere comfort, there are good reasons why we need artificial gravity on long distance space missions. For one, experiencing relative weightlessness for long periods of time changes our bodies

in ways that could be harmful. When astronauts arrive at their destinations such as an asteroid or Mars, or when they return to Earth after some time in low gravity, bones lose mineral content, meaning they soften, becoming vulnerable to fracture.

Muscles atrophy meaning they shrink and weaken. The fluids shift toward the head and are also excreted from the body, causing changes in the cardiovascular system in the lungs, the nervous systems thrown out of whack, and in recent years, space medicine researchers have found what could be permanent eye damage in some astronauts due to the reshaping of the

eyes lenses. Add to that, research suggesting that gravity may be required for humans to have a normal pregnancy in space, and it seems almost like a no brainer that any spacecraft carrying humans around the Solar System should either rotate or have some part of the ship that does so. Are NASA and others researching this possibility. The answer is yes, absolutely. Since the nineteen sixties, NASA scientists have been considering the

prospect of artificial gravity by way of rotation. However, the effort, funding, and overall enthusiasm has waxed and waned through the decades. There was a surge in research in the nineteen sixties when NASA was working on sending people to the Moon, though the budget for NASA at that time was nearly five percent that of the entire federal government, ten times

what it is today. While NASA has not emphasized research on artificial gravity over the past half century, scientists both inside and outside of the Space Agency are studying a range of situations. Mice spinning in a small centrifuge aboard the International Space Station survived with no problem, and earthbound humans are learning how to adapt in spinning rooms. For example, the DLR Institute of Airspace Medicine in Cologne, Germany, is

home to the DLR Short Arms Centrifuge Module one. It's the only one of its kind in the world researching the effects of altered gravity, especially as it pertains to health risks that occur in microgravity, and the University of Colorado Boulder is studying waste design revolving systems that could fit in a room of a future space station or moon base. Astronauts could crawl into these rooms for just a few hours a day to get their daily dose

of gravity. But if the need for artificial gravity is so clear, why bother with research in space or on Earth. Why don't engineers simply get to work designing spinning ships like the fictional Hermes. The answer is that artificial gravity requires a trade off because all that spinning creates problems. As on the rotor ride, moving your head while you're

spinning that fast causes nausea. It impacts the fluid in your inner ear and any other body parts that you move while you're in a rotating environment, and that nausea

and disorientation worsen the faster you rotate. That is, as you increase the number of revolutions per minute or r p ms, and the amount of artificial gravity that can be produced depends on both those RPMs and the size of whatever is rotating to experience a given amount of gravity, for example, one half the usual amount that you feel

on Earth. The length of the radius of rotation, that is, the distance from you standing on the floor to the center of whatever is spinning, determines how fast you need to spin. Build a wheel shaped craft with a radius of seven and thirty eight feet that's two d and twenty five, and you'll produce the equivalent of normal Earth gravity known as one G, rotating at just one revolution per minute. That's slow enough that scientists are pretty sure

that nobody would get nauseated or disoriented. Other than the floor being a bit curved, things aboard such a craft would feel pretty normal, but building and flying such an enormous structure in space would entail a lot of engineering challenges. This means that NASA and any other space agencies or organizations likely to send people around the Solar System in the future must either settle for a lower amount of gravity,

faster rotation that is more RPMs, or both. The Moon has a surface gravity of about six that of Earth's surface, which makes it a great place to research the effects of low gravity, but there are no laboratories on the Moon it. There simply isn't enough data to know how much gravity humans may need for long term space missions or in space colonies, which means more research is needed, as is data on how much rotation humans can reasonably tolerate.

Today's episode was written by David warm Flash and produced by Tyler Clang. For more on this and lots of other heavy topics, visit how stuffworks dot com. Brain Stuff is production of I heart Radio. For more podcasts to my heart Radio, visit the i heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows