NASA develops new gears able to withstand the extreme cold of the Moon

One of the challenges of exploring space and other locations is extreme cold. During the NASA Artemis mission to the moon, temperatures on the South Pole will drop drastically during the night. At some point in the future, NASA wants to explore Europa, one of Jupiter's moons where temperatures never get above -260 degrees Fahrenheit at the equator. NASA has been preparing for these frigid temperatures by developing special gears able to withstand extreme temperatures.

In low temperatures, gears and the housings in the gearbox are heated. After being heated, a lubricant helps the gears function correctly and prevents the steel alloy from becoming brittle and eventually breaking. NASA has been conducting a project called Bulk Metallic Glass Gears (BMGG), and the project team created a material made of "metallic glass" that can function and survive in extreme cold without heating.

Eliminating the need to heat the gearbox reduces the amount of energy the spacecraft needs to function. NASA notes that operations in cold and dim environments are limited currently because of the amount of power available on a rover or lander. The energy saved with the new gearbox could extend the mission duration or allow more instruments to be placed on the spacecraft rover.

During testing at JPL, engineers mounted the motor and gearbox on a turntable beam designed to measure the response to shock or forceful impact. Liquid nitrogen was used to cool the gears down to approximately -279 degrees Fahrenheit. A steel projectile was then fired at the beam to simulate a shock event.

This type of shock testing is used to determine if spacecraft hardware will break during events like reentry, decent, and landing. Testing also simulated how the gears might behave when collecting a regular sample during the night on the moon. Before each shock test, researchers poured liquid nitrogen over the motor and gearbox. After the liquid nitrogen was drained within a few seconds, the impactor fired at the steel beam the motor and gearbox are mounted to. The gearbox and motor were shock tested twice in three different orientations, and with each demonstration, the gears survived the shock event at extremely low temperatures.