Heather Oravec holds a spare aluminum tire for the Mars Curiosity rover in the Simulated Lunar Operations Lab in Cleveland, Ohio. (AP)

Heather Oravec holds a spare aluminum tire for the Mars Curiosity rover in the Simulated Lunar Operations Lab in Cleveland, Ohio. (AP)

Ms. Oravec, a research associate professor stationed at the NASA Glenn Research Center, demonstrates on a tire made of the nickel titanium shape-memory alloy. (AP)

Ms. Oravec, a research associate professor stationed at the NASA Glenn Research Center, demonstrates on a tire made of the nickel titanium shape-memory alloy. (AP)

The fine-grained surface of Mars is a challenge for rovers. (NASA)

The fine-grained surface of Mars is a challenge for rovers. (NASA)

Ms. Oravec’s research in the characteristics of extraterrestrial soil has helped in developing new tires for off-world vehicles and rovers. (AP)

Ms. Oravec’s research in the characteristics of extraterrestrial soil has helped in developing new tires for off-world vehicles and rovers. (AP)

This memory-metal tire can deform but then return to its original shape. (AP)

This memory-metal tire can deform but then return to its original shape. (AP)

Triumphant Tires

Posted: November 1, 2019

Spirit was stuck. Its tires were sinking. They kept spinning, spewing fine-grained particles into the atmosphere. The rover ground to a halt on the sandy surface of the red planet. NASA’s Mars rover sent one last signal back to Earth before going silent. The mission failed. 

That was nine years ago. Heather Oravec’s job is to make sure future rovers don’t spin out in space like Spirit did. She’s confident that memory-metal tires will triumph over Mars’ tricky terrain. 

Ms. Oravec is a mechanical engineering professor at the University of Akron. She also works at NASA’s research center. According to Ms. Oravec, the Mars rover sank in “some of the worst-case conditions.” She knows a lot about the sandy, rocky terrain on Mars. She also knows how hard it is for tires to grip that type of soil. 

NASA doesn’t have samples from Mars’ surface to work with. But they have the next best thing—Ms. Oravec! She’s an expert on extraterrestrial dirt. She made her own fake Mars soil. (It’s called GRC-1.) She uses it to test new tire designs. 

Her latest design is made from a nickel-titanium alloy. Its nickname is “memory metal.” The airless tires are lighter in weight and can carry heavier loads than tires used in the past. When the new metal tires cruise over rugged terrain, they wrap around rocks. Then, they bounce back to their original shape—just like memory foam!

When you place your hand on memory foam, the foam makes a handprint. What happens when you remove your hand? The foam holds the dent before slowly returning to its original shape. That’s exactly how the new rover tires work. Their memory metal design absorbs the shape of rocks. This prevents tire damage. 

According to NASA’s website, the nickel-titanium alloy is a game changer for rover tires. NASA knows good tires are important if you want to get from one place to another—even in space. 

There is a long history of space inventions improving things we use every day. How would you like to have memory metal tires on your mountain bike? Imagine the places you could go!