The Ultimate Roller

Now he wants to mount KR 500s to a track and speed them along one after another. Propel a rider on a twisting, undulating trip while shaking him like a cat would a rat, and you greatly compound the physical stimulation. Which brings us to the project's highest hurdle: the upchuck factor. If your inner ear and your eyes send conflicting messages to your brain about your body's position–say, an alien lands on your ship, but the ride jerks a tenth of a second later-the illusion is shattered, and your body could revolt. Paul Evans, a mechanical designer at the engineering firm AMEC Dynamic Structures, which is partnering with RoboCoaster, is programming a series of KR 500 maneuvers to match, frame-by-frame, a 3-D film of a roller coaster ride, in large part to determine which moves are too . . . sick. "We don't exactly know what the human body will tolerate when we combine extreme movements with 3-D imagery," he says. The amusement-park industry doesn't keep tabs on nausea, though, so how will De-Gol ensure that his ride is thrilling and enjoyable? "Guest satisfaction cards will tell us a lot," he enthuses. "The beauty is that we can simply go in and reprogram it."