Reinventing the Wheel

Planning a trip to the Moon? Mars? You’re going
to need good tires…

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Exploration requires mobility. And whether you’re on Earth
or as far away as the Moon or Mars, you need good tires to get your vehicle
from one place to another. Our decades-long work developing tires for space
exploration has led to new game-changing designs and materials. Yes, we’re
reinventing the wheel—here’s why.

Wheels on the Moon

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Early tire designs were focused on moving hardware and
astronauts across the lunar surface. The last NASA vehicle to visit the Moon
was the Lunar Roving Vehicle during our Apollo
missions
. The vehicle used four large flexible wire mesh wheels with stiff
inner frames. We used these Apollo era tires as the inspiration for new designs
using newer materials and technology to better function on a lunar surface.

Up springs a new idea

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During the mid-2000s, we worked with industry partner
Goodyear to develop the Spring
Tire
, an airless compliant tire that consists of several hundred coiled
steel wires woven into a flexible mesh, giving the tires the ability to support
high loads while also conforming to the terrain. The Spring Tire has been
proven to generate very good traction and durability in soft sand and on rocks.

Spring Tires for Mars

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A little over a year after the Mars Curiosity Rover landed
on Mars, engineers began to notice significant wheel damage in 2013 due to the
unexpectedly harsh terrain. That’s when engineers began developing new Spring Tire
prototypes to determine if they would be a new and better solution for
exploration rovers on Mars.

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In order for Spring Tires to go the distance on Martian
terrain, new materials were required. Enter nickel titanium,
a shape memory alloy with amazing capabilities that allow the tire to deform
down to the axle and return to its original shape.

These tires can take a lickin’

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After building the shape memory alloy tire, Glenn engineers
sent it to the Jet Propulsion Laboratory’s Mars Life Test Facility. It
performed impressively on the punishing track.

Why reinvent the wheel? It’s worth it.

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New, high performing tires would allow lunar and Mars rovers
to explore greater regions of the surface than currently possible. They conform
to the terrain and do not sink as much as rigid wheels, allowing them to carry
heavier payloads for the same given mass and volume. Also, because they absorb
energy from impacts at moderate to high speeds, there is potential for use on
crewed exploration vehicles which are expected to move at speeds significantly
higher than the current Mars rovers.

Airless tires on Earth

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Maybe. Recently, engineers and materials scientists have
been testing a spinoff tire version that would work on cars and trucks on
Earth. Stay tuned as we
continue to push the boundaries on traditional concepts for exploring our world
and beyond.  

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