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.