The Spring Tire was installed on NASA’s Lunar Electric Rover test vehicle and put through its paces at the Johnson Space Center’s "Rock Yard" in Houston where it performed successfully.
"This tire is extremely durable and extremely energy efficient," noted Jim Benzing, Goodyear’s lead innovator on the project. "The spring design contours to the surface on which it’s driven to provide traction. But all of the energy used to deform the tire is returned when the springs rebound. It doesn’t generate heat like a normal tire.
According to Goodyear engineers, development of the original Apollo lunar mission tires, and the new Spring Tire were driven by the fact that traditional rubber, pneumatic (air-filled) tires used on Earth have little utility on the moon. This is because rubber properties vary significantly between the extreme cold and hot temperatures experienced in the shaded and directly sunlit areas of the moon. Furthermore, unfiltered solar radiation degrades rubber, and pneumatic tires pose an unacceptable risk of deflation.
Take a look at this Spring Tire test drive video.
(NASA's spring tire video)
The Spring Tire is touted as giving back most of the energy used to compress the tire as it moves forward. An ordinary Earth pneumatic tire keeps a significant amount of the energy used to roll it forward. The "rolling resistance" of tires accounts for about 5 percent of the total energy used by your car or truck. Hopefully, NASA vehicle mileage should be better.
I don't think that a tire made entirely of springs was predicted by sf writers. However, Arthur C. Clarke was on the right track with what he called "flex-wheels" in his 1968 novel 2001: A Space Odyssey:
Most of them moved on balloon tires, for this smooth, level plain posed no transportation difficulties; but one tanker rolled on the peculiar flex-wheels which had proved one of the best all-purpose ways of getting around on the Moon. A series of flat plates arranged in a circle, each plate independently mounted and sprung, the flex-wheel had many of the advantages of the caterpillar track from which it had evolved. It would adapt its shape and diameter to the terrain over which it was moving, and, unlike a caterpillar track, would continue to function even if a few sections were missing.
Read more about Spring Tires at NASA and Goodyear (press release); thanks to the reader who submitted this story. (BTW, although I may not write an article for every reader story idea, I really appreciate reader article idea suggestions.)
Scroll down for more stories in the same category. (Story submitted 8/5/2009)