INVESTIGATION OF THE PHYSICAL AND MECHANICAL PROPERTIES OF CHANG'E-5 LUNAR REGOLITH USING MICRO-CT
Dr Qi Zhao is an Assistant Professor at the Civil and Environmental Engineering Department at the Hong Kong Polytechnic University (PolyU). He obtained his PhD degree at the University of Toronto and then worked as a postdoc at the University of Toronto and UC Berkeley before joining PolyU. He is a recipient of the Leopold Müller Award by the Austrian Society for Geomechanics and the Dr N.G.W. Cook PhD Dissertation Award by the American Rock Mechanics Association (ARMA). He was selected to be a Future Leader of ARMA in 2021. He is the founding management committee member of the Research Centre for Deep Space Explorations at PolyU. His research focuses on developing novel geomechanics and geophysics solutions for sustainable urban development and deep space exploration.
In this talk, I will present a comprehensive study of the Chang'e-5 (CE-5) lunar regolith samples using X-ray micro-computed tomography (micro-CT) and machine learning-based segmentation techniques. This non-destructive, non-contact approach allowed us to extract and analyze three-dimensional image data from over 700,000 lunar soil particles. Our findings reveal that the CE-5 samples have a median particle size of 57.5 micrometers, notably smaller than those from Apollo and Luna missions, and exhibit complex particle morphology with lower sphericity. Density-based image analysis enabled us to evaluate the mineral composition, identifying glass and plagioclase at 45.6%, pyroxene and olivine at 49.7%, and ilmenite at 4.7%. Leveraging these insights, we developed the PolyU-1 lunar regolith simulant using Earth-derived mineral materials, ensuring high consistency with CE-5 samples in terms of particle morphology and composition. Experimental measurements of its physical and mechanical properties, including friction angle and cohesion, provide valuable references for lunar regolith mechanics. This research underpins future lunar exploration and in-situ resource utilization efforts.