The Moon, as the celestial body closest to Earth, is a prime target for human deep space exploration. China's Lunar Exploration Project IV aims to explore and sample the lunar polar region's water-containing regolith. To effectively simulate the characteristics of this watery lunar regolith, this paper proposes a deep low-temperature preparation system. The feasibility of the system design is validated through theoretical and methodological analysis, including cold source selection, heat dissipation analysis, and energy consumption calculations. Subsequently, a deep low-temperature aqueous lunar regolith preparation system was developed, and tests were conducted to verify its performance. The results confirm that the system can generate water-containing lunar regolith at -238 degrees C and maintain its temperature during drilling. This capability is significant for subsequent research on the drilling performance of deep low-temperature watery lunar regolith.

Rapid and partial acquisition are features of rock drilling for obtaining rock properties. Most previous research has primarily concentrated on how to quickly obtain rock mechanics parameters, with limited emphasis on extracting rock parameter fields, particularly in three dimensions. This study attempted to develop a numerical integrated method to extract 3D parameter fields of rocks based on a newly developed digital-controlled drilling platform. The importance of incorporating a damage model for accurate simulations of rock drilling through finite element analysis (FEA) was investigated. By calibrating damage parameters through uniaxial compressive strength (UCS) and Brazilian tensile strength (BTS) tests, these parameters can be considered constants in rock drilling simulations across various rock types. The accuracy of rock parameters estimated by the proposed method and the derived analytical model were further demonstrated through comparison with the corresponding standard tests. Furthermore, the 3D parameter field of rocks was obtained by integrating a deep learning method and micro-CT technology. The numerical prediction illustrated the advantages of acquiring a rock parameter field in achieving more accurate simulations of the rock failure process. Besides, our solution can also provide support for the parameter selection of numerical models considering spatial variability for natural rocks. A digital-controlled equipment for rock drilling was developed.Equations were derived for extracting rock parameters through the drilling data.A deep learning method was developed to reproduce the three-dimensional parameter field of rocks.The significance of considering the realistic rock parameter field was numerically demonstrated.

To provide reliable input information for the load design and extraction of lunar soil water ice samples, it is necessary to study the water content distribution and water migration of simulated lunar soil water ice samples. On this basis, the temperature field model and the hydrothermal coupling relationship are proposed. The temperature field model was constructed by combining energy conservation and Fourier's heat transfer law. The coupling relationship was established, and the hydrothermal coupling model was obtained by testing the unfrozen water content using the nuclear magnetic resonance method. Finite element software was used to solve the model numerically, and the water migration rule of the soil water ice samples at different ambient temperatures were analyzed. Thin-wall drilling tests were carried out on the simulated lunar soil water ice samples to obtain water content data for different locations, and the simulation results were verified. Due to the migration effect of the cold end of the water, the closer we tested to the edge of the sample, the higher the water content was. The higher the ambient temperature was, the more pronounced the water migration phenomenon of the whole sample was. These research results provide a basis for sampling scheme design.

A novel method to evacuate large bins of lunar regolith simulant for deep drilling tests was proposed in the current work. This method can be used to simulate a vacuous lunar regolith environment to a maximum penetration depth of 2 m. An experimental apparatus was built and is composed of a vacuum chamber, a specially designed regolith container and a vacuum pumping system. A pressure on the order of 10 Pa could be reached with the 4.3 m(3) vacuum chamber when compacted lunar regolith simulant with a volume of 0.4 m(3) was loaded. A theoretical model to predict vacuum degree was proposed bas'ing on the viscous flow theory. Evacuation experiments with or without lunar regolith simulant inside the chamber were performed and the outgassing properties of lunar regolith simulant was experimentally studied. The results show that the outgassing rate of the lunar regolith simulant was about 10(7) times to that of the electro-polished stainless-steel.