|Spring Tires are shown here mounted to NASA’s Scarab lunar roving vehicle.|
The Spring Tire overcomes the load-bearing and distance limitations of tires previously used on NASA’s Apollo Lunar Roving Vehicle, and offers high resiliency even when damaged, making it ideal for harsh terrestrial environments on Earth. The really innovative thing about the tire is its design: it contains load-bearing helical springs that conform to the contours of the terrain surface while consuming less energy than conventional pneumatic rubber tires. Less energy absorption by a Spring Tire can also improve fuel economy of the vehicle on which it is mounted. Because it is constructed without any air or rubber, the tire can be used in the harsh temperature extremes of space and as a safer alternative for military and off-road vehicles. Remarkably, the spring tire will still function even when up to 25 percent of its springs have been damaged. In military and off-road applications that encounter bullets and sharp terrain, this is a critical success feature.
When driven under load, the tire’s support springs passively contour to the terrain by flexing and moving with respect to each other. These springs are interwoven radially across the tire, allowing them to deform without twisting, turning, or significantly interfering with adjacent springs.
The Spring Tire will enable potential future NASA missions to use rovers and exploration vehicles designed for ten times the load capacity and one hundred times the distance of the original Apollo vehicle.