Development of Endurance Testing Apparatus Simulating Wheel Dynamics and Environment on Lunar Terrain 2010-01-0765

This paper entails the design and development of a NASA testing system used to simulate wheel operation in a lunar environment under different loading conditions. The test system was developed to test the design of advanced nonpneumatic wheels to be used on the NASA All-Terrain Hex-Legged Extra-Terrestrial Explorer (ATHLETE). The ATHLETE, allowing for easy maneuverability around the lunar surface, provides the capability for many research and exploration opportunities on the lunar surface that were not previously possible. Each leg, having six degrees of freedom, allows the ATHLETE to accomplish many tasks not available on other extra-terrestrial exploration platforms. The robotic vehicle is expected to last longer than previous lunar rovers. The rover is expected to: - Able to move at 10 km/h over Apollo-like terrain (≻100 times faster than Mars Exploration Rover (MER)), - Climb vertical steps of at least 70% of the maximum stowed dimension of the vehicle (≻2x MER), - Climb slopes of 35° on rock and 25° on soft sand, - Load, transport, manipulate, and deposit mock payloads in a useful fashion.

However, in order to ensure this is possible, the wheels of the vehicle, the unit which will experience the greatest wear and possess the greatest risk of premature failure, must be capable of supporting the operation of the rover over its projected lifetime. The lunar wheels, made of advanced nonpneumatic technology, required testing simulating the lunar environment under different loading conditions. To measure and ensure the wheels are capable of withstanding endurance lunar environment operation, a testing system is designed and constructed to simulate the environment on the Moon and measure the dynamics of the wheel. The test system was used to simulate the low temperature environment of the Moon and the dynamics of the wheel under different driving conditions. This was performed to view characteristic changes within the wheel as time progressed and to measure the life expectancy of the wheel and to aid in developing further prototypes of the lunar nonpneumatic wheel.