Out of This World Tires
By David A. Kolman
Many of the products we take for granted today have come about from technologies developed as the National Aeronautics and Space Administration (NASA) has sent men, women and automated vehicles into space. Cell phones, cordless power tools and appliances, home insulation, global positioning systems, body imaging and much, much more are the result of the transfer of NASA technology to the private sector.
A recent development that I foresee impacting the transportation industry is the airless tire developed by NASA and Goodyear. This unusual tire, dubbed the Spring Tire is capable of transporting large, long-range vehicles across the surface of celestial bodies such as the moon or Mars.
The Spring Tire is constructed out of 800 load-bearing springs which provide stiffness and flexibility, as well as puncture-proof toughness. It is designed to carry much heavier vehicles over much greater distances than the wire mesh tire that was previously used on the Apollo Lunar Roving Vehicle. The new handmade Spring Tire is expected to allow for broader exploration and the eventual development and maintenance of planetary outposts. It might also have applications on Earth.
Goodyear says the Spring Tire is exceptionally durable and extremely energy efficient. 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. The airless tire 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 was driven by the fact that traditional rubber pneumatic tires have little utility on the moon. Rubber properties vary significantly between the extreme cold and hot temperatures experienced in the shaded and directly sunlit areas of the moon. What’s more, unfiltered solar radiation degrades rubber, and pneumatic tires pose an unacceptable risk of deflation. Because the Spring Tire doesn’t have a single point failure mode, a hard impact that might cause a pneumatic tire to puncture and deflate would only damage one of the 800 load bearing springs.
With its design, the Spring Tire would avoid puncture failure for considerably reduced vehicle downtime and repairs costs, plus save energy. Because the tires conform to rough terrain and operate reliably in remote and hostile locations, they would be particularly beneficial on military, mining, on-/off-road, construction and trash-hauling vehicles.
Wouldn’t it be nice to not have to worry about regularly checking tire air or being concerned about a flat?