Morphological Characteristics Study of Chang’e-5 Lunar Regolith Particles for In-situ Resource Utilization on Moon

Abstract:

The morphological characteristics of lunar regolith particles have a significant impact on in-situ excavation， transportation， 3D printing， and other processes on the Moon. The samples obtained independently by China’s Chang’e-5 mission can provide key parameter information for the construction of the lunar research station. This paper focuses on the morphological characteristics of lunar regolith particles that are of concern in the process of in-situ resource utilization on the Moon. Optical microscopy was used to obtain images of the Chang’e-5 lunar regolith particle samples approved by Tongji University， a set of image processing and particle recognition methods were constructed， and a directional difference index was proposed to characterize the roughness of the particle surface. The automatic extraction of particle edges and the calculation of their size and morphological indicators were achieved. The results show that the particle size range of the studied Chang’e-5 samples is 4.36~792.30 μm， with an average aspect ratio of 0.66， an average circularity of 0.806， and an average directional difference index of 0.111. Small particles make up a large proportion， with particles below 10 μm accounting for 44.19%. The directional difference index of the particles is approximately normally distributed， indicating that a large number of particles have similar surface roughness， with a small number of particles having smoother or rougher surfaces. There is a negative correlation between the size and aspect ratio， circularity of small particles， and little correlation with surface roughness. There is no correlation between the size and morphology of large particles. The study also found that the circularity of the particles in the Chang’e -5 samples is smaller and the morphology is more irregular in comparison with the Apollo 11 and Apollo 15 samples.