Abstract
Lunar surface operations conducted by the United States and the Soviet Union confirmed that penetration resistance is a key indicator for evaluating the engineering properties of lunar regolith. To quantitatively assess the influence of reduced gravity on penetration resistance, this study employed a newly developed Geotechnical Magnetic-gravity Modeling Test (GMMT) system to perform cone penetration tests under controlled gravitational acceleration levels of 1/6 g, 1 g, and 2 g. The results indicated that the normalized penetration resistance increased as gravity decreased, and this effect was amplified at higher relative densities. To investigate the underlying mechanisms, discrete element method (DEM) simulations were conducted. The findings revealed that, in addition to gravity, in situ factors such as high relative density and irregular particle morphology also significantly enhanced penetration resistance by strengthening interparticle contact and friction. These non-gravitational effects partially offset the expected reduction in resistance under lower gravity, leading to a smaller-than-anticipated decline. This study provides new insights into the gravity-dependent penetration behavior of lunar regolith.
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Data availability
All the relevant data relating to this study are available upon reasonable request to the co-authors. In addition, the Magnetic Levitation System used in this study can be accessed by contacting the corresponding author. Experimental use of the system is permitted following participation in the required training and approval procedures. All the relevant codes relating to this study are available upon reasonable request to the co-authors.
Code availability
All the relevant codes relating to this study are available upon reasonable request to the co-authors.
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Acknowledgements
The authors would like to acknowledge the China Postdoctoral Science Foundation (2025M773218), the financial contributions from the Fundamental Research Funds of the China Academy of Safety Science and Technology (2025JBKY03), the National Natural Science Foundation of China (42372329), and the Basic Research Program of Xuzhou (KC23019).
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J.C. performed the data curation, investigation, visualization, and wrote the original draft. J.C. and R.L. contributed to funding acquisition. R.L. also provided supervision and resources. F.S. contributed to the review and editing of the manuscript. All authors have read and approved the final version of the manuscript.
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Chen, J., Li, R. & Fu, S. Influence of low gravity on the penetration resistance of lunar regolith. npj Microgravity (2026). https://doi.org/10.1038/s41526-026-00562-8
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DOI: https://doi.org/10.1038/s41526-026-00562-8
