Towards Ultra-Deep Exploration in the Moon: Modeling and Implementation of a Mole-Type Burrowing System

ABSTRACT Effective scientific exploration of extraterrestrial locations requires reaching subsurface destinations and obtaining geology samples of high scientific value. One of the most widely used techniques for geological sampling is drilling, but there is still a need for investigation to achieve greater depth and efficiency. This paper proposes a mole-type autonomous burrowing robotic system for drilling, steering, and accessing scientific samples from the deep subsurface of the Moon. The paper describes the robotic locomotion and operational loads of the self-burrowing robot. The self-burrowing robot with dual-screw configuration is designed and a mathematical model is developed to simulate its excavating capacities. Finally, the paper discusses the robot's performance and compares it with conventional drilling methods using the specific energy method. INTRODUCTION The core of near-earth exploration missions, such as those to the Moon, Mars, or asteroids, is extraterrestrial subsurface drilling and sampling (Gorevan et al., 2003). The primary tools for gaining insights into the evolutionary history of the solar system are subsurface exploration equipment, such as coring machines or robots. To achieve scientific objectives, it is necessary to reach the subsurface destination and obtain geological samples of high scientific value (Glass et al., 2020). Typically, the lunar subsurface within about 10 meters in depth consists of igneous regolith and disturbed materials from fine granular particles to chunky rocks along the depth direction (Slyuta, 2014). Drilling is one of most widely used techniques in geological sampling for sand or soil. These have been implemented in extraterrestrial exploration, in missions such as Luna, Apollo and Chang’e (Prissel & Prissel, 2021). Towards the deep exploration and samples collection in subsurface, there are proposed the conceptual designs or prototypes. This recent research focused on the new technical system to achieve deeper and more efficient soil movement (Lopez-Arreguin & Montenegro, 2020), which imitates locomotion mechanisms of animals and insects such as crawling, swimming, and burrowing in granular mediums. Among these developed bio-inspired robot, typical prototypes, the inchworm robots, such as IDDS (Gorevan et al., 2000) and IBR (Zhang et al., 2018), operate sequentially combining the actions of anchoring and drilling. The wood wasp robots (Cerkvenik et al., 2019) mimic a reciprocating motion of two halves saw-toothed bits to shear and stick into the soil.