Goodyear, Michelin airless tire concepts could anchor NASA's Artemis

Sixty years ago, NASA and astronaut John Glenn pushed the limits of possible. Three times. Once for every orbit around the earth.

Since then, NASA's every step has redefined possible, shaping the reality of what we know and what we can achieve. It started with Mercury, Gemini and Apollo, then moved to the space shuttle program and International Space Station.

Now there's Artemis, a mission on which NASA is building a new foundation for a new era of space exploration.

"Apollo was very much about how to send humans out into space," NASA Deputy Administrator Pam Melroy said in a statement. "We built on that legacy with the space shuttle, which taught us how to do science and how to stay in orbit for periods at a time. The International Space Station has taught us how to live 24/7 365 days a year and do science in space. But Artemis is going to take us out to the next step."

That's because Artemis isn't just about going to the moon. It's about staying on the moon. It's learning about the moon so we can learn to live on the moon.

Because beyond the moon is Mars. And so, so much more.

"Artemis will help us define: What are the objectives? What are the things that we had to demonstrate? What do we have to learn and understand before we go the next step to Mars?" Melroy said. "We get to practice on the moon, which is just a couple of days away from earth. It's a place where we can practice, learn and prepare ourselves for future exploration to Mars and beyond."

To live and move and explore, NASA's astronauts will need the right connections to the lunar surface. And that's where Goodyear and Michelin come in. Each of the tire makers are playing key roles on engineering teams designing lunar vehicles for the Artemis missions.

Pushing the limits of possible in aerospace is as much a part of Goodyear as its tires, Michael Rachita, senior program manager on Goodyear's nonpneumatic tires team, told Rubber News. From balloons and dirigibles to blimps and lunar tires, Goodyear's done it.

In fact, Goodyear was on the lunar surface before the rovers themselves.

"There was a need for a manned instrument cart that the astronauts would pull," Rachita said. "And Goodyear developed a pretty small rubber-based, nitrogen-based pneumatic tire, which is what was actually up there before the metal-mesh-based tires—the nonpneumatic tires—that were on the rovers."

This time, when Goodyear returns to the lunar surface it plans to do so with next-generation nonpneumatic tires, developed all around the expertise gained in the last 60 years, especially with its partners at NASA's Glenn Research Center in Cleveland.

It's a collaboration that Rachita said dates back about 15 years. Somewhere around the mid-2000s, NASA Glenn embarked on a mission of its own: to re-create and understand the original lunar tires in the hopes of taking the technology—and the space program—further.

"They were interested in relearning that technology because they did have an eye about going to the moon again and ultimately going to Mars," Rachita said. "… We are very familiar with each other and we worked directly with them to, first of all, re-engineer the original, and we actually rebuilt it and built quite a few of them. And then we used modern tire metrology to retest it.

"You can imagine the testing they did in-house in the 1960s. It has advanced, right? We can do a lot more and then learn: OK, it doesn't load the characteristics we want for a new modern class of rover. And so we did some inventive work around the new architecture and that is what has led to the kind of work we have right now, which is our three-dimensional, spring-like, metal-based structure, and it has been a great starting point for this new Artemis mission."

For Artemis, specifically, Goodyear has teamed up with General Motors and Lockheed Martin, bringing its decades of lunar tire and nonpneumatic tire expertise to the collaborative lunar vehicle project.

Space is a frontier Michelin knows well.

The tire maker's NASA connections hearken back more than 30 years to the space shuttle program, for which the South Carolina-based tire maker provided tires. From there, the partnership grew into lunar tire development for exploration vehicles.

Ultimately, it's the lunar vehicle tire development experience that is serving as the solid foundation for Michelin's next mission: designing and developing lunar tires for Artemis as part of a project with Northrop Grumman, AVL, Intuitive Machines and Lunar Outpost.

"At Michelin, we are very proud to be a part of the Northrop Grumman Lunar Terrain Vehicle Team," David Chapman, Michelin North America vice president of government and defense, told Rubber News. "… Traveling back to the moon aligns very well with Michelin's purpose to provide Motion for Life. We remain at the forefront of innovation and are proud to contribute to NASA's return to the moon."

Together the tire maker and its aeronautics and vehicle technology partners will design and develop a lunar vehicle capable of handling any challenge the lunar surface and atmosphere can throw at it.

But it will be Michelin's nonpneumatic tire that connects the vehicle to the moon. And it's an airless tire that Michelin has designed around what Chapman calls "a reusable organic core," putting the company's sustainability mission at the heart of its extraterrestrial one as well.

Because the core of Artemis' Missions is to better understand the lunar environment, NASA is targeting the moon's south pole where the extremes of the environment truly test the ability of the earth materials and the tires they comprise.

"This time around, we want to go to some more of the more interesting scientific, geographical and geological regions, and that just happens to be the poles," Rachita said. "They do believe there is trapped water—sort of like a permafrost—in some of those areas, and they want to try to prove that."

Proving it—and harnessing it for both water, oxygen and energy—is one thing. Doing all of that in temperatures that fall below minus 350°F is another.

And it's something that presents a challenge for both tire makers.

"That (temperature) puts polymers, that puts rubber/elastomers and most plastic composites completely out of scope," Rachita said. "It is so cold they would literally be in their brittle frozen state. And that could be fine for body panels, that could be fine for components that don't flex and fatigue. But by definition, a tire's use is to flex and fatigue over and over and over.

"So it is finding the appropriate materials, and we believe, for us, that is in the metal space. That is alloys and special composition of alloys that can survive cryogenic temperatures and still perform in such a way that it can last way more than two days (as with the Apollo Missions). The goal is lasting for years of driving around."

Extreme temperatures are just one of the two biggest challenges faced by the Goodyear team. The other, Rachita said, has to do with the lunar surface.

"The surface of the moon itself has been determined by being there—by the astronauts—to be extremely sharp, very abrasive," he said. "It has never been weathered by atmosphere. So no running water that softens the sides of quartz and minerals, no air blowing over it for millions of years. And so, it is razor sharp, which means anything that touches it is prone to just abrade away. … And the one piece of that vehicle that is touching the surface is the tire. So finding materials that are hard enough and can survive such an aggressive, abrasive base for so long makes it difficult."

When it comes to decoding the moon's unknowns, Michelin believes it is up to the task, according to Chapman. It has exactly the materials science expertise needed to tackle some of the biggest lunar challenges.

And while the tire maker didn't offer any specifics about the tire it envisions sending to the moon as part of the Artemis missions, Chapman did emphasize the tire maker's extensive materials development as being key to its success.

For the Artemis endeavor, specifically, Michelin has harnessed its materials science expertise in the same way it does for every earth tire it rolls out. Because Michelin is more than the tires it is best known for, Chapman said. It is a materials science company that is exploring and developing high-tech materials across a range of industries.

And it's that expertise that is going to help take the tire maker to new places in space.

"Expertise in materials technology has been driving Michelin's growth for more than 130 years," Chapman said. "We're investing in high-tech materials so we can use renewable resources in all our tires and create exciting new applications in a range of industries—from aerospace to biotech.

"During the group's long history, our teams of physicists and chemists have acquired exceptional expertise in high-tech materials, their production process and applications. Michelin stands out in the tire industry for its ability to combine materials to create new functionalities and uses."