Bridgestone's Lunar Rover Tire Concepts Are Totally Metal And Ready To Rock
Japanese tire maker Bridgestone is showing off two new lunar rover tire concepts at the 40th Space Symposium in Colorado Springs. Yes, they basically look like airless puncture-proof tires currently found on UTVs (utility task vehicles) and skid steer loaders, except that Bridgestone's are metal and designed to withstand that harshness of outer space. This "AirFree" initiative is part of the company's 2024-2026 Mid-term Business Plan that aims to bring the tire/wheel tech to upcoming lunar rover flights and beyond.
At the 40th Space Symposium in Colorado Springs this week—the largest event of its kind in the United States—the Bridgestone Corporation is exhibiting two concept lunar rover tire models that feature lower weight and greater durability. The smaller version (shown above) is meant for small-sized rovers, while the larger, more complex model (below) can be mounted on medium-sized rovers.
These airless tires are actually Bridgestone's third attempt. The second generation (previewed at last year's Space Symposium) wore soft, metal-based felt material that were supposedly inspired by the footpads of camels. These threads were part of a wheel structure consisting of thin metal spokes and could provide enhanced frictional bite on regolith, a.k.a. the moon's soft sandy surface.
The new models sidesteps that heavier metal felt material for a simpler friction surface reminiscent of recovery boards used for off-roading. Bridgestone hopes that the drop in weight will not only increase maneuverability, but also improve durability. The tire-maker hasn't detailed what kind of metals are being used to fabricate the new tires, but in general, metal rover wheels are made of space-grade steel, aluminum, or some alloy.
One such example is the aluminum wheels used on the Mars Curiosity rover. The threads were milled out of a solid block of aluminum, while the springy spokes are titanium. Over the years, Martian rock spikes have punctured through the metal threads, but so far the wheel structure hasn't been compromised. That said, these wheels (as well as the rover) have far exceeded their operational lifespan, which says a lot about the viability of metal-based wheels/tires in space exploration.
The 2025 Space Symposium runs this week, starting today till the 10th. To check out the Bridgestone lunar tires for yourselves, look for the Japan Space Industry's display space (pun intended).
