CAMBRIDGE, Mass. -- There is no doubt that
future Red Planet explorers will be more than a little weak-in-the-knees after a round-trip jaunt lasting some three years.
Research shows that exposure to microgravity weakens muscle, causes bone loss and plays havoc with a person's balance and coordination.
But a team of scientists and engineers here at the Massachusetts Institute of Technology's (MIT) Man-Vehicle Laboratory are tackling the problem with experiments in
artificial gravity.
Big wheel, keep on turning
Artificial gravity has long been viewed as the most effective way to prevent deconditioning of space travelers.
Student experimenters are in for a spin at MIT.
In the 1950's, for example, space visionary
Wernher von Braun saw a huge, rotating space station to keep occupants fit and functional. So too did moviemaker Stanley Kubrick and writer Arthur Clarke in the two-thumbs-up sci-fi epic, 2001: A Space Odyssey.
But now there's a new spin on creating artificial gravity.
"There's the growing notion that we must get away from a large and expensive-to-build spinning wheel and get down to something considerably smaller," said MIT's Laurence Young, professor of aeronautics and astronautics.
Young and his colleagues are hard at work on investigating use of a personal centrifuge. Just a few yards (meters) in radius, the device is too small to live in.
Yet an astronaut could get something akin to a gravitational massage using the scheme.
"I call it a spin in the gym," Young told SPACE.com. "You go into such a device for a workout, just like you go to the gym," he said.
Questions still remain, Young admits. What gravity level is best and along what axis of the body should
g-force exposure be applied? What is the minimum radius centrifuge you can get away with? How much of a g-force is needed and for what duration in time?
"We don't have a great many answers now. But we know what some of the questions are," Young said.
G-wizards
MIT Man-Vehicle Laboratory researchers feel they are on the right track, and a rotating one at that.
"My personal view is that artificial gravity is the only countermeasure that can remove the cause for space deconditioning. The countermeasure pill has not yet been invented, and I believe it never will be," said Heiko Hecht, a post-doctoral researcher at the lab.
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Hecht said that it would be delusional to believe humans can travel to Mars and return in good health without an effective way to combat the adverse
effects of prolonged weightlessness.
Studies are now underway to find out whether short-radius intermittent spins in a centrifuge will do the trick, Hecht said. Perhaps one to two hours a day of spinning, combined with exercise, might be the answer, he said.
However, there are side effects in using short-radius devices, said Kathleen Sienko, a Ph.D. student at MIT in health sciences and technology.
"We want to show that it's worthwhile looking at artificial gravity as a universal countermeasure," Sienko said. But there are key issues needing more work, she said.
Spin doctors, Heiko Hecht (left) and Larry Young, prepare subject for centrifuge test.
For instance, how best to combat sensory illusions and
motion sickness due to repeated changes between a person's state of weightlessness and a state of artificial gravity.
Revolutionaries
To help sort out answers, volunteers have been put on a spin-cycle at the MIT lab.
For some student subjects, a little centrifuge time looks good on the resume, particularly if your career goal is becoming an astronaut, said Lisette Lyne, a Ph.D. student at the lab.
At a flat rate of $10 per hour, carefully screened subjects are strapped flat to a 6.6-foot (2-meter) radius rotating bed. A canopy is placed over the individual, who is also outfitted with instrumented headgear.
On the centrifuge, a person's head is placed at the center of rotation, while the feet are at the rim. The centrifuge spins at 23 revolutions per minute, creating a one-gravity force at the feet of a 5-foot, 5-inch (1.7-meter) tall person.
Sienko said a range of responses have been measured.
An objective of the work, both Sienko and Lyne said, is to show whether or not astronauts can maintain a dual adaptation. That is, can they easily move between doing daily "free-floating" duties to the countermeasure of a rotating environment?
Moreover, researchers said, can space travelers move back and forth between these conditions without symptoms of illusory self-motion or motion sickness?
World of trouble
Lyne said there is another major issue.
As far as a trip to Mars goes, no medical care will be waiting to meet and greet astronauts
touching down on the Red Planet. If the vestibular system is impaired or compromised, a resulting fall due to unbalance could result in a bone fracture, a completely broken bone, or even death, she said.
"If you don't provide gravity on the way and maintain your cardiovascular system, maintain healthy bones, and keep up your calcium, you could be in a world of trouble. There are no hospitals. You're on your own in a very remote place," Lyne said.
Professor Young said that moving artificial gravity experiments into space is paramount. "We're going to have to get some experience with spinning humans in space," he said.
NASA will consider carrying a short-radius centrifuge on a future shuttle mission, Young said. Furthermore, new work on artificial gravity is being supported through the National Space Biomedical Research Institute in Houston, Texas, he said.
Young stresses that artificial gravity is one of several innovative ideas being pursued. But the countermeasures now in effective use for short-duration space missions "are inadequate Band-Aids" for long haul crews headed for Mars, he said.
"We have to get off dead center where we've been for almost 20 years," Young said.
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