Lunar regolith simulants incorporating impact product simulants for surface engineering and exploration applications

Reliable assessment of lunar surface engineering behavior requires regolith simulants that realistically capture both the mechanical response and impact-derived characteristics of natural lunar regolith. Although numerous lunar regolith simulants have been developed for geotechnical testing, most remain insufficient in reproducing the structure and mechanical role of impact products such as agglutinates and impact breccias, which dominate the load-bearing framework of lunar regolith. In this study, we establish a fabrication route for lunar regolith simulants that combines thermal processing of basalt-derived materials with glass-phase incorporation and subsequent mechanical crushing. Using this method, two simulant series, THIP-5 and THIP-6, are designed to represent regolith conditions at the Chang’e-5 nearside and Chang’e-6 farside landing regions, respectively. Systematic laboratory characterization demonstrates that the impact product simulant generated with 25 wt.% hollow glass beads reproduce key morphological and micromechanical features of natural lunar impact products. Comparisons of bulk scale properties further reveal that the synthesized simulants closely match their corresponding target soils across multiple physical and compositional metrics, including mineralogy, chemistry, grain-size characteristics, and density-related parameters. Furthermore, static angle of repose tests show that THIP-5 exhibits behavior comparable to established Chang’e-5 simulants, while experimental results from THIP-6 enable an estimation of the static angle of repose of the Chang’e-6 regolith at approximately 52.8°. The THIP simulant framework provides a physically grounded experimental basis for investigating lunar regolith mechanics, supporting the design of surface infrastructure, mobility systems, and future astronaut operations on the Moon.