The modern version is called the Spring Tire, so-called for the 800 load-bearing springs that make up its bulk, mounted to a six-spoke metal hub. The springs can conform to the varying terrain of other planets and satellites without transferring undue shock to the vehicle, and a malfunction is likely to damage only a few of them, leaving the tire operable.
See below for more info from Goodyear on the tire, and check it out in the gallery of high-res photos. When it's time for another group of astronauts to go "ridin' dirty," this is likely how they'll do it.
Geneva, Switzerland, March 6, 2012 – The Goodyear 'Spring Tire', which was co-developed by The National Aeronautics and Space Administration (NASA), represents a future tire concept that could be used to explore the outer reaches of space, and possibly the most brutal terrains here on earth.
The Spring Tire offers 800 load bearing springs and is designed to carry heavy vehicles over much greater distances than the wire mesh tire previously used on the Apollo Lunar Roving Vehicle (LRV), which Goodyear also helped design and construct in 1971. The air-less tire could allow for broad exploration and potential development of future outposts on the moon, or possibly allow vehicles to travel to places on earth where current tires could never go.
"This tire is extremely durable and very energy efficient," noted Joe Lettieri, Goodyear's lead researcher on the Spring Tire project. "The spring design contours to any surface providing maximum traction. All of the energy used to deform the tire is returned when the springs rebound, so it will not generate heat like a pneumatic tire."
While a hard impact might cause a pneumatic tire to puncture and deflate, any trauma to the Spring Tire would likely only damage one of the 800 load bearing springs. Along with having this ultra-redundant characteristic, the Spring Tire has a combination of overall stiffness yet flexibility that allows off-road vehicles to travel fast over rough terrain with relatively little motion being transferred to the vehicle.
According to NASA and 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 a high risk of deflation on the moon.
In 2010, Goodyear was honored with the R&D 100 award for its Spring Tire technology. Goodyear continues to run tests on Spring Tire in their R&D laboratories to determine potential applications for this technology. The Spring Tire will be on display on the Goodyear Dunlop stand 2056 at the 2012 Geneva International Motor Show from March 8-18.
Goodyear is one of the world's largest tire companies. It employs approximately 73,000 people and manufactures its products in 53 facilities in 22 countries around the world. Its two Innovation Centers in Akron, Ohio and Colmar-Berg, Luxembourg strive to develop state-of-the-art products and services that set the technology and performance standard for the industry. For more information about Goodyear and its products, go to www.goodyear.com.