Deployable wood wasp drill for planetary subsurface sampling

Growing interest in planetary subsurface exploration has prompted an examination of advanced drilling technologies. One of the major limitations of sampling in low gravity environments (such as Mars, asteroids, etc.) using conventional rotary drills is the need for high axial force, which suffers from big overhead mass, buckling problem, and power hungriness. Though drills using percussive motion may operate in low mass and power, the drilling rate is generally slow. Drawing inspiration from nature for a lightweight and energy efficient solution, we propose a novel drilling method based on the working mechanism of wood wasp ovipositors. The bio-inspired drill requires no reactive external force by applying two-valve-reciprocating motion. The proposed biomimetic system indicates enhanced utility that is critical for space missions where premium is placed on mass, volume and power. Biological systems are similarly constrained making biomimetic technology uniquely suited and advantageous as a model of miniaturized systems. As a result of the European Space Agency (ESA) project on bionics and space system design [Ellery et al., 2005], this paper presents a conceptual design of the wood wasp drill. Lab-based experiments have shown that the bio-inspired drilling method is feasible and has potential of improving drill efficiency without any additional overhead force or mass

1. Introduction

It is widely acknowledged that the next significant challenge in planetary exploration is the ability to drill deep into the surface of solar system bodies. Examples include astrobiological research to search for biomarkers about 2~3 m beneath the surface layer of most solar bodies (such as Mars [1]). Studies at lunar south pole region aim to search for water ice that is likely to exist under 1~2 m depth. The deep drilling system is therefore a crucial on-board instrument that can enable surface penetration, autonomous sample acquisition, and preparation for either in situ experiments or sample return procedures. ESA's ExoMars and ESA/NASA's Mars Sample Return missions scheduled for 2011 and 2016 will both require deep drilling capability and a great amount of work has to be performed in this area.