Particle Morphology Controls the Bulk Mechanical Behavior of Far-Side Lunar Regolith from Chang'e-6 Samples and Deep...

Area of Science:

• Lunar geology
• Regolith characterization
• Geotechnical engineering

Background:

• Lunar far-side exploration is crucial for understanding lunar evolution.
• South Pole-Aitken basin samples provide unique insights.
• In situ resource utilization (ISRU) requires detailed regolith knowledge.

Purpose of the Study:

• Characterize the geotechnical properties of lunar far-side regolith.
• Establish benchmarks for lunar exploration and ISRU.
• Analyze particle morphology and its impact on mechanical behavior.

Main Methods:

• Integrated framework: X-ray micro-computed tomography (XRMCT) and semisupervised machine learning.
• High-throughput analysis of 349,740 individual lunar regolith particles.
• Discrete element method (DEM) simulations using high-fidelity particle morphologies.

Main Results:

• Far-side regolith particles are more irregular (median diameter 60.51 μm, mean 3D sphericity 0.74) than near-side samples.
• High internal friction angle (47.96°) and cohesion (1.08 kPa) indicate enhanced mechanical strength.
• Particle irregularity and interlocking are primary drivers of superior mechanical properties.

Conclusions:

• Lunar far-side regolith possesses distinct and superior geotechnical properties compared to near-side materials.
• Findings provide critical design parameters for future lunar missions and infrastructure.
• Enhanced mechanical strength supports potential for robust ISRU and construction on the lunar far-side.