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.