The next Mars rovers may traverse the Red Planet with futuristic tires.
NASA's Glenn Research Center released imagery and footage from testing of a novel tire, called a shape memory alloy spring tire, that would be capable of incurring significant deformation on rugged terrain, before springing back to its original shape.
"We can actually deform this all the way down to the axle, and have it return to shape, which we could never even contemplate in a conventional metal system," Santo Padula, a materials research engineer at NASA Glenn, explained in a new agency video.
The space agency recently tested the tires on Martian-simulated terrain at Airbus Defence and Space in the United Kingdom. The engineers reported the tires passed testing on the rocky and slippery artificial topography — an encouraging endorsement of the technology.
The springy metal is composed of nickel-titanium, a material that can withstand intense stresses. (Previous NASA spring tire designs used steel, which more easily leads to irreversible deformation.) The current rovers on Mars, Perseverance and Curiosity, are built with tires made of aluminum and have grown battered and punctured as they crunch over the wild Martian desert.
Future extraterrestrial rovers — especially if they're crewed vehicles on Mars or the moon — would certainly benefit from damage-resistant tires. It won't be easy to fix a flat or punctured tire on another world.
Such a self-repairing material might be vital for structures, too. The moon, for example, has almost no protective atmosphere, meaning its surface is often pelted with speeding micrometeorites. "We need new materials for extreme environments that can provide energy absorption for micrometeorite strikes that happen on the moon to enable things like habitat structures for large numbers of astronauts and scientists to do work on the moon and Mars," Padula said.
Who knows — perhaps future Mars rovers, moon bases, and even moon railroad cars will contain springy metal, designed for the extremes of other worlds.
