As NASA prepares to establish the Moon Base, advancing surface mobility will be key to helping crews and robotic systems travel farther across the lunar surface.
To help advance that capability, the Rock and Roll with NASA Challenge invited public innovators to design and build next-generation lunar rover wheels.
Five teams from 128 submissions and 49 countries advanced to the final phase of the competition, where they tested their prototypes on July 31 at NASA’s Johnson Space Center in Houston.
The challenge sought lightweight, durable, and scalable wheels that could support longer-duration lunar surface operations. The designs also needed to be compliant enough to absorb impacts, maintain traction at higher speeds, and withstand the harsh lunar environment.
“Every additional kilometer a rover can reliably travel will expand how far we can explore, what science we can achieve, and what infrastructure we can build,” said Ed Herrera, robotics engineer at Johnson and co-leader of the challenge project.
NASA Johnson uses ground prototypes to test mobility technologies, while lunar terrain vehicles will be delivered to the lunar surface through the Commercial Lunar Payload Services initiative. For the challenge, the wheels were fitted to MicroChariot, a 45-kilogram test rover, and put through a series of courses at Johnson’s Rock Yard to evaluate their performance across different types of terrain.
“Crowdsourcing gives us an opportunity to look beyond traditional approaches for lunar wheel design,” Herrera said. “The more wheel technologies we can develop and understand, the more options we have to meet the needs of different vehicles, terrains, and missions on the Moon and Mars.”
Those ideas were reflected in five distinctly different designs.
The HTR Variable Flex Lunar Wheel created by Hellenic Technology of Robotics SA uses an internal system designed to vary the wheel’s stiffness depending on terrain and vehicle needs. The team adapted technology it had been developing for terrestrial wheels for about a decade.
The Hiper Wheel created by Hyperbola uses tensioned cables and a corigated structure that provides spring-like behavior, allowing the wheel to flex without relying on traditional radial spokes.
The Huff Helo Flexible Titanium Wheel created by Huff Helo Inc. uses formed titanium sheet metal as both structure and spring. During testing, the team found that the strength of the design also made the wheel more rigid, causing it to bounce over some obstacles rather than conform to the terrain.
The Payne Aviation Wheel created by Deborah and Craige Payne took inspiration from aviation and history. Its designer, an aircraft mechanic, combined a pneumatic approach with ideas from early automobile tire designs.
The winning Scotch Pad Tyres concept came from an Australian mechanical engineer Daniel Bloomfield and his son Isaac Bloomfield. Their prototype uses a Nomex-based tire structure supported around an aluminum hub. The soft material allows the tire to deform around terrain, while internal support helps it maintain its shape. A treated outer surface of epoxy and corundum grit was integrated to improve traction.
The Rock Yard testing also demonstrated why different terrains may require different approaches. Loose material can affect traction, while rocks and slopes place different demands on wheels such as vehicle stability.
As lunar exploration expands, different vehicles will require different combinations of speed, load capacity, durability, and terrain performance.
Seeking that variety was part of the challenge design. The design options gave engineers different technologies to consider and potentially advance.
“This challenge brought in new ideas from outside traditional industries and helped us identify wheel technologies that may be suitable for longer-duration surface operations,” said Lucien Junkin, robotics engineer at Johnson and co-leader of the challenge project.
The next phase could evaluate how the wheels respond to lunar-like dust, vacuum, and extreme temperatures in Johnson’s thermal vacuum chambers. Engineers could also assess the designs over longer distances and at different sizes and loads.
“Mobility is key to everything we want to do on the Moon,” Junkin said. “The farther we want to explore, the more we need to advance the wheel technologies that can get us there.”
The Common Robotics Project of the Robotic Systems Technology Branch within Johnson’s Engineering Directorate conducted the Rock and Roll with NASA Challenge. NASA’s Center of Excellence for Collaborative Innovation, part of the Prizes, Challenges, and Crowdsourcing Program within the Research and Technology Mission Directorate, managed the challenge contract. Students in NASA’s Robotics Academy helped prepare hardware and support the competition, while engineers from NASA’s Glenn Research Center in Cleveland supported reviews of concepts and proposals. HeroX administered the challenge on behalf of NASA.
