How Do You Change a Tire on the Moon?
When the new lunar mobility vehicle takes its first spin around the moon, it will be sporting a familiar logo on its wheels: Goodyear’s. But unlike the tires on your car, the lunar vehicle’s will be airless, made entirely of metal and clad in mesh.
Yet, the lunar tire isn’t entirely a separate beast, according to Goodyear Senior Program Manager for Non-Pneumatic Tires Michael Rachita. The tires might be rolling around the moon, but they are closely related to some Earth-bound technology—and will help that technology evolve even further.
- Rachita chatted with us recently about Goodyear’s contributions to the lunar mobility vehicle, which is being designed and built by Lockheed Martin and GM for deployment later this decade (read our interview with Lockheed Martin Vice President for the Lunar Exploration Campaign Kirk Shireman).
- It is intended to stay on the moon for years, both supporting NASA missions and functioning autonomously when the astronauts are not around. Here’s what Rachita told us about the tires that will make it all possible.
The design: A traditional rubber tire simply wouldn’t work on the moon, Rachita explains. It wouldn’t hold its air pressure in the vacuum of space, and without an atmosphere to filter out the sun’s radiation, the rubber would quickly degrade.
- Instead, Goodyear will be using metal alloys, such as aluminum and special steels. As Rachita puts it, “You can tap into the standard materials that are used in satellites as a starting point”—materials that are already tried and tested for space.
The environment: These are some of the environmental factors that engineers must consider, says Rachita.
- Temperatures: The moon undergoes extreme transitions in temperature, ranging from -280 degrees Fahrenheit at night to 260 degrees Fahrenheit during the day.
- Gravity: At only 1/6th that of Earth’s, the moon’s gravity changes the calculation of flexibility. The metal tires act something like a spring, but since objects bear down with much less weight on the moon, the tires must be correspondingly more flexible than they would have to be on Earth, Rachita explains.
- Moon dust: The lunar regolith is sharp, abrasive and electrostatic, says Rachita, and acts something like very soft sand. In designing these tires, Goodyear has taken inspiration from off-roading techniques used for sandy or rocky areas, such as deflating tires to create a soft, broad surface that almost floats over the landscape.
Read the full story here.