NASA tests five prototype wheels for future Moon-base rovers

At NASA’s Rock Yard in Houston, five unusual wheels took turns carrying a small rover over rough ground on July 31. The test was the final phase of a public competition that began with 128 submissions from 49 countries, all aimed at solving a basic problem for a future Moon base: how to keep vehicles moving when every rock, slope and patch of loose soil matters.

NASA fitted the prototypes to MicroChariot, a 45-kilogram test rover, and ran them across several types of terrain. The challenge asked for wheels that were lightweight, durable and scalable, but also flexible enough to absorb impacts, maintain traction at higher speeds and withstand the lunar environment. Loose material tested grip; rocks and slopes tested stability.

The winning design came from Australian mechanical engineer Daniel Bloomfield and his son Isaac. Their Scotch Pad Tyres prototype uses a Nomex-based tire structure around an aluminum hub. The material deforms around uneven ground, while internal support helps the wheel retain its form. A treated outer surface made with epoxy and corundum grit was integrated to improve traction.

The other finalists pursued different answers. Hellenic Technology of Robotics SA built a wheel whose internal system can vary stiffness with terrain and vehicle needs. Hyperbola used tensioned cables and a corrugated structure to create spring-like flex without traditional radial spokes. Huff Helo formed titanium sheet metal into both structure and spring, but found that the wheel’s strength also made it rigid enough to bounce over some obstacles. Payne Aviation combined a pneumatic approach with ideas from early automobile tires.

So what changes in practice? These are ground-tested prototypes, and the agency says the next step could include thermal-vacuum tests with lunar-like dust, vacuum and extreme temperatures, plus longer runs and different loads. But the competition gives engineers several mechanisms to investigate rather than betting on one design: NASA says different lunar vehicles may need different balances of speed, load capacity, durability and terrain performance.