Robotic drilling for the Chinese Chang'E 5 lunar sample-return mission

On December 2, 2020, a 2-m class robotic drill onboard the Chinese Chang'E 5 lunar lander successfully penetrated 1 m into the lunar regolith and collected 259.72 g of samples. This paper presents the design and development, terrestrial tests, and lunar sampling results of the robotic drill. First, the system design of the robotic drill, including its engineering objectives, drill configuration, drilling and coring methods, and rotational speed determination, was studied. Subsequently, a control strategy was proposed to address the geological uncertainty and complexity of the lunar surface. Terrestrial tests were conducted to assess the sampling performance of the robotic drill under both atmospheric and vacuum conditions. Finally, the results of drilling on the lunar surface were obtained, and the complex geological conditions encountered were analyzed. The success of the Chinese Chang'E 5 lunar sample-return mission demonstrates the feasibility of the proposed robotic drill. This study can serve as an important reference for future extraterrestrial robotic regolith-sampling missions.