Refined Gearbox Design for the Chariot Lunar Rover

In planning for NASA’s return to the moon by the year 2020, the NASA Johnson Space Center (JSC) designed and built a lunar concept vehicle called Chariot. Slightly larger than a pickup truck, it was designed to demonstrate similar utilitarian functions, but with twelve wheels for redundancy, reliability, and reduced surface contact pressure. JSC designed a motor gearbox to drive each of Chariot’s six wheel pods. The pods can be independently steered over 360° for maneuverability. This paper describes the design of a second generation, drop-in replacement gearbox. The new design has a lower parts count, and is lighter than the original, which represents a step toward flight hardware.