Bearings From Muskegon At Work On Mars — For The Third Time
MUSKEGON — The Curiosity rover that landed on Mars Aug. 6 features the largest, most advanced scientific payload of any Mars mission yet — and, as usual, Reali-Slim thin section bearings.
The five pairs of duplexed bearings from Kaydon Bearings Division in Muskegon save space and weight in two important areas: preparing rock material samples for analysis and supporting the steering actuators for the rover’s wheels.
The one-ton Curiosity, about the size of a small SUV, will analyze samples drilled from rocks or scooped from the ground to assess whether the environment near its landing site might once have been able to support life. The rover was designed, developed and assembled by the Jet Propulsion Laboratory, a division of the California Institute of Technology, for NASA’s Science Mission Directorate.
One pair of duplexed Reali-Slim bearings is in the CHIMRA (Collection and Handling for In-Situ Rock Analysis), one of a number of devices mounted on a turret at the end of the rover’s robotic arm. These angular contact bearings with a three-inch outside diameter are a key part of the “thwack” mechanism that must keep the primary sieve from clogging so that samples can reach the analytical instruments. The screens in the sieves have tiny holes — 150-micron and 1mm — to produce particles of the appropriate size. JPL engineers decided early on that thin section bearings were the best way to handle the load in the small space available, and built the design around them.
The other four sets of Kaydon bearings (7-inch outside diameter, 6-inch bore) support the steering actuators on Curiosity’s four corners and relieve some of the load on them, which was critical during the landing. These bearings, like those in the CHIMRA, are angular contact in duplex pairs, with races and balls of 440C stainless steel and a built-in preload. JPL requested that all be shipped dry, including the phenolic separators, so they could add a space-rated lubricant that would not turn viscous in the extreme cold or evaporate in the thin atmosphere.
With a typical speed of about one inch per second, this latest rover is expected to cover about 660 feet of Martian terrain per day when it begins collecting samples in September. For the next 23 months it will send data, images and a variety of scientific observations back to Earth, where scientists hope the $2.5 billion mission will shed light on the question of whether there is — or has ever been — life on Mars.
Kaydon Bearings Division (www.kaydonbearings.com) is a leading global manufacturer of standard and custom thin section bearings, high-level bearing assemblies, and slewing ring bearings for a wide range of manufacturing and process applications. The division is also a major supplier of remanufactured and new replacement bearings.
Kaydon Corp. (www.kaydon.com) is a leading designer and manufacturer of custom-engineered, performance-critical products, supplying a broad and diverse group of alternative-energy, industrial, aerospace, medical, and electronic equipment, and aftermarket customers.