The Johnsville G Machine Sucked Astronauts' Teeth Out the Back of Their Heads

John Glenn is an American hero. He orbited the Earth at 17,526 mph and ain't scared of a damn thing—except, of course, the Johnsville human centrifuge. That "sadistic" machine terrified Glenn and his fellow astronauts for more than 50 years at the Naval Air Warfare Center in Pennsylvania. Here's how. »10/28/11 1:40pm10/28/11 1:40pm