Thibault Gouache (cofounder of Cornis), did his PhD for ESA (European Space Agency), in collaboration with ISAE (Toulouse, France) and the University of Surrey (Guilford, UK) in the field of automatic and mechanics. A strong expertise in design, assessment, evaluation and testing of space mechanisms was acquired.
On the moon or Mars to search for traces of life, it is mandatory to dig or drill beneath the surface. Any drilling system needs an important force applied on it to penetrate; On the Moon and Mars there is little gravity and the mass of space systems is limited. It is thus very difficult if not impossible to push on classical space drilling systems. New drilling solutions re thus necessary.
Novel mechanisms for lunar and Martian regolith penetration, exploration and sampling were designed, prototypes and tested. Thanks to the observation of nature (an insect drilling into wood to lay its eggs), a team of researchers funded by ESA (European Space Agency) designed a drilling system based on the alternative and reciprocating translation of 2 valves. The alternating movement enables a significant reduction of the normal force that must be applied by the carrier on the drill head.
A first prototype was developed for regolith type substrates (sandy soils). To conduct performance tests, it was necessary to define a standardised protocol to test drilling systems in regolith substrates. Thanks to this protocol, objective comparisons between different drilling systems performance in regolith is made possible. The influence of relative density of the regolith that is being penetrated is controlled and reported.
To confirm the experimental conclusions of this work, numerical simulations using DEM (discrete element methods) and a highly parallelized code compatible with GPU were used. The experimental and numerical data enabled to conclude that the studied drilling system is able to penetrate efficiently into regolith with very little over-head normal force mainly because the drill head-shape causes a lateral deflection during the reciprocating translations.