With an eye on future trips to Mars, NASA scientists are putting human guinea pigs aboard a 58-foot centrifuge in Mountain View this summer to see how well they tolerate long-term exposure to increased gravitational force.
At press time, seven Stanford students were still in the pool of 30 candidates for the hypergravity experiment, which sought men between the ages of 18 and 35 who were 5-foot-8 or shorter (women will take part in a subsequent study). “They have to be sufficiently small to fit, and they have to really, really want to participate,” says Malcolm Cohen, chief of NASA’s human information processing branch and a consulting professor in human biology. The passenger cabs where the four finalists will spend seven “habitation sessions”—five of them some 22 hours long—are only 6 feet wide and 7.6 feet long.
Cohen first studied the effects of hypergravity on military jet pilots in the 1960s, and has been teaching Astrobiology and Space Exploration at Stanford since 1982. In this experiment, he hopes to find out if long-term exposure to hypergravity might help astronauts readjust to gravity on Earth—after extended periods of weightlessness on space flights—without debilitating side effects. As the centrifuge spins faster and faster, the study subjects will try to ride it out as they experience G forces up to two times those normally found on Earth. They’ll spend most of their time sitting upright, playing chess or Pong on laptops, or watching videos.
“We’ll be looking to see if they remain reasonably functional in a rotating environment for long periods of time, and testing them to see if their G tolerance is improved or compromised and whether they have severe motion sickness,” Cohen says. “They’ll spend some time standing, but they may not want to walk much.”
