Analysis on Drilling and Coring Process and Lunar Regolith Stratification State Interpretation in Chang’E-5

Chang'e-5 lunar mission has gathered lunar regolith on the surface and sub-surface by an automatic sampling process combined by drilling and excavating, achieving the return of the lunar soil sample. The telemetry data from drilling and coring process on lunar surface reflects the interaction between the sampler and in-suit lunar regolith, which can improve the scientific value of the drilling and coring process by its analysis and interpretation. According to the system constitution, principle and performance index of drilling and coring device, and typical operation conditions are defined by the characteristics of the telemetry data. Based on the interaction mechanism between coring drill and lunar regolith and the test data from drilling experiments on Earth, the analysis of lunar regolith composition and characteristics are presented with the fluctuation drilling loads of the drilling and coring process. The explanation of the lunar regolith stratification state in the drilling site is given. The analysis indicates that the regolith stratification in Chang'E-5 drilling spot has at least three different composition and properties, and millimeter-size particles are existed in the drilling spot. The drilling and coring device has fully performed with its efficiency facing the unknown lunar regolith profile, and the outlook about future extraterrestrial regolith profile sampling technique of China is introduced.