1A2-K04 Research of Self-Turning Screw Mechanism for Lunar/Planetary Exploration(Space Robotics and Mecahtoronics)

Methods of underground installation of some geophysical sensors such as seismometers and heat flow sensors are required for future lunar and planetary exploration. On the Moon, the installation below several tens centimeters makes these sensors able to survive during the night without any thermally shielded mechanism. On the other hand, methods of driving piles into the regolith would help robots to operate, because it is very difficult to obtain enough reaction force in the regolith which is powdery and soft. In 2008, we proposed a new mechanism we called "Self-Turning Screw Mechanism (STSM) which uses reactive torque of a wheel for drilling into the regolith. In this paper, we report the concept of the STSM, the design of our recent prototype and the result of experiment. The length, diameter, and weight of the prototype are 364.6mm, 80mm, and about 2.5kg respectively. In the latest test, the prototype could drill at a depth of 648mm into flyash sand which simulates the lunar regolith. This result proved applicability of the mechanism to autonomous drilling system in the future landing missions.