Search Results (145)

Utilizing lunar regolith as a raw material for structural components offers significant potential for future lunar exploration. Direct manufacturing from unprocessed regolith reduces the need for specialized refining equipment compared to element extraction methods. At present, the mechanical properties of long-term alkali-activated CQU-1 lunar regolith simulant geopolymer (LRSG) columns have not been studied. To address this, forty-eight CQU-1 LRSG cylindrical specimens were prepared and tested under axial compression in this study. The effects of the curing temperature (60 °C and 80 °C), curing time (3 d, 7 d, 14 d and 28 d), and water–binder ratio (0.325 and 0.455) on the failure modes and stress–strain behavior were investigated. The alkali-activated CQU-1 LRSG achieved a maximum compressive strength of 33.89 MPa under optimal conditions. Elevated curing temperatures and extended curing times enhanced peak stress and elastic modulus while reducing peak and ultimate strains, indicating greater stiffness and brittleness. Conversely, increased water–binder ratios flattened stress–strain curves, diminishing slope and peak stress while elevating peak and ultimate strains. Based on these test results, the stress–strain model, elastic modulus model and peak strain model of alkali-activated CQU-1 LRSG were proposed. The proposed models can accurately predict the stress–strain relationship, compressive strength and ultimate strain of alkali-activated CQU-1 LRSG. The influence of curing temperature, curing time, and water–binder ratio on the performance of alkali-activated CQU-1 LRSG is also discussed in detail. This work confirms the viability of the alkali-activated CQU-1 LRSG and lunar regolith-based geopolymers for future extraterrestrial construction. Full article

Robust, lightweight, and thermally insulating building materials, developed according to the In Situ Resource Utilization (ISRU) paradigm, are essential for enabling Moon settlements. With this aim, we have investigated the formulation and characterization of porous geopolymeric materials based on a lunar regolith simulant, focusing on the influence of surfactants and rheology-modifying additives on pore structure and final material performance. As an optimized procedure, a pre-formed TTAB foam was, in fact, incorporated into the geopolymeric precursor slurries to achieve a suitable porosity. Then, the effects of three thickeners (xanthan gum, bentonite, and Actigel-208) were evaluated in view of the possible utilization for the production of building blocks by 3D printing. Observations of the pore structure after the geopolymeric consolidation of the slurries showed predominantly closed-cell networks across all formulations, with a pore morphology strongly dependent on the thickener used. Xanthan gum promoted high porosity but reduced mechanical integrity, whereas bentonite produced denser structures with higher thermal conductivity. Actigel-208 provided the most balanced performance, combining adequate porosity with improved strength. These findings demonstrate the potential of producing thermally insulating, structurally stable solid foams from lunar regolith simulants via a geopolymerization route. Full article

Accurate mapping of lunar mineral distributions is essential for understanding the Moon’s origin and evolution and for enabling future in situ resource utilization (ISRU). Yet mineralogical inversion from orbital hyperspectral observations remains challenging due to limited spatial resolution, complex photometric conditions, and sparse returned samples. We present PGU-Net, a Hapke physics-guided deep autoencoder for nonlinear blind unmixing of lunar hyperspectral data. The encoder adopts a dual-attention design to enhance discriminative spectral features. The decoder performs linear mixing in the SSA domain and then reconstructs reflectance through a lightweight nonlinear module, while physics-consistent losses encourage radiative-transfer plausibility. Experiments on a synthetic lunar regolith dataset demonstrate that PGU-Net achieves consistently lower endmember SAD and abundance aRMSE than representative baselines across multiple noise levels. Additional validations on the terrestrial AVIRIS Cuprite benchmark and on Moon Mineralogy Mapper (${\mathrm{M}}^3$) observations near the Chang’e-5 (CE-5) and Chang’e-6 (CE-6) landing regions yield physically plausible mineral distributions. The ${\mathrm{M}}^3$ maps are broadly consistent with Kaguya MI mineral products and returned-sample constraints, supporting the practicality of PGU-Net for lunar mineralogical mapping. Full article

Understanding the mechanical behavior of lunar regolith is critical for the success of future lunar excavation and construction missions. Irregular particle morphology and low geostatic stress are recognized as key factors contributing to the high internal friction angle of this unique extraterrestrial geomaterial. However, the underlying mechanisms by which low geostatic stress enhances shear strength remain unclear, and the multiscale effects of particle morphology on shear strength evolution are not yet fully elucidated. In this study, consolidated drained triaxial compression tests were performed on CUMT-1 lunar regolith simulant and Fujian standard sand to investigate their macroscopic mechanical behavior. Complementary discrete element simulations of biaxial compression were conducted to analyze mesoscopic mechanical responses of granular materials under the influence of multiscale particle morphology and confining stress. A robust macroscopic–mesoscopic strength correlation model was established, incorporating normalized mean interparticle contact force and mean coordination number to predict the normalized deviatoric stress of granular assemblies. Based on this model, the mesoscopic mechanisms through which irregular particle morphology and low geostatic stress enhance the internal friction angle were quantitatively investigated. The findings offer new insights into the shear strength characteristics of in situ lunar regolith and provide theoretical support for lunar surface construction and excavation operations. Full article

Future lunar mining missions are expected to involve deeper geological conditions. Understanding the mechanical behaviors of the lunar subsurface regolith is essential to operational safety. Recent findings from the Chang’e-4 and Chang’e-5 missions revealed a marked increase in particle size and relative density of lunar regolith with depth. In addition, the geostatic stress naturally increases with depth. These three variables pose significant challenges for accurately predicting the shear strength. Existing predictive models, such as the Alshibli model, fail to account for the distinct conditions of lunar subsurface regolith. To address this, consolidated drained triaxial tests were conducted on the CUMT-1 lunar regolith simulants. The influences of confining pressure, relative density, and particle size distribution on shear strength were systematically analyzed. A novel indicator, named inter-particle void ratio, was introduced to capture the combined effects of relative density and particle size distribution. Based on this indicator, a new empirical model was proposed for predicting peak shear strength under varying subsurface conditions. The results suggest that deeper lunar regolith may have significantly lower shear strength than previously estimated, primarily due to the combined effect of increased inter-particle void ratio and geostatic stress. This finding has important implications for the assessment of excavation efficiency, underground construction stability, and the overall safety of lunar subsurface infrastructure. Full article

The lunar surface soil (regolith) represents a potential substrate for crop cultivation in future extraterrestrial bases. However, the absence of indigenous microbial activity severely limits nutrient availability in lunar soil. In this study, the effects of three commercial microbial fertilizers on improving simulated lunar soil and promoting lettuce (Lactuca sativa L.) growth were experimentally evaluated. The results showed that microbial fertilizers significantly increased the contents of available nutrients (N, P, and K) and organic matter in simulated lunar soil, thereby enhancing lettuce growth and biomass accumulation. Compared with the treatment without adding microbial fertilizer application (CK), the aboveground and belowground fresh weights of lettuce increased by up to 91.61% and 89.08%, respectively, under the microbial fertilizer MLQ treatment. In addition, microbial fertilizer treatment increased nutrient accumulation and photosynthetic pigment contents in lettuce, alleviated oxidative stress by improving antioxidant system performance, and consequently enhanced lettuce quality. High-throughput sequencing analysis further revealed that the dominant bacterial genera under these conditions were Bacillus, Glutamicibacter, Acetobacter, Enterococcus, and Microbacterium, while the dominant fungal genera included Saccharomyces, Pichia, and Trigonopsis. These findings provide theoretical support for the development of functional microbial fertilizers tailored for simulating lunar soil. Full article

Two challenges that have a permanent presence on the Moon are solar and cosmic radiation, as well as the large surface temperature variation between lunar day and night. To address these problems, we propose a lunar pathfinder mission concept that uses robotic systems to investigate whether regolith-filled bags can be used as a versatile construction medium for lunar surface structures and sensors to obtain data on the lunar regolith. The primary objectives of this mission are as follows: evaluation of the surface and subsurface regolith as fill material, lunar excavation using a robotic manipulator equipped with a bucket scoop, bag filling using a proposed robotic bagging system, the stacking of the filled bags with a robotic manipulator into a simple berm structure, and verification of the completed regolith-filled bag berm. Additional objectives include assessing the local radiation environment and testing Wi-Fi technology for use in and around a lunar surface station, such as the proposed Artemis Base Camp. Where possible, high TRL technologies are presented for each mission objective, which will be carried to the lunar surface on a Commercial Lunar Payload Services (CLPS) lander. A novel regolith bagging system concept is presented. The feasibility of the overall mission concept is studied by investigating key mission parameters, which shows the presented technologies fulfill all mission parameters. Potential extended mission concepts that exercise increased levels of autonomy are also presented, which may provide additional data to inform the development of this technology for future, at-scale, deployment. Full article

Accurate perception of deformable objects on the lunar surface is essential for autonomous construction and in situ resource utilization (ISRU) missions. However, the lack of representative lunar imagery limits the development of data-driven models for pose estimation and manipulation. We present SynBag 1.0, a large-scale synthetic dataset designed for training and benchmarking six-degree-of-freedom (6-DoF) pose estimation algorithms on regolith-filled construction bags. SynBag 1.0 employs rigid-body representations of bag meshes designed to approximate deformable structures with varied levels of feature richness. The dataset was generated using a novel framework titled MoonBot Studio, built in Unreal Engine 5 with physically consistent lunar lighting, low-gravity dynamics, and dynamic dust occlusion modeled through Niagara particle systems. SynBag 1.0 contains approximately 180,000 labeled samples, including RGB images, dense depth maps, instance segmentation masks, and ground-truth 6-DoF poses in a near-BOP format. To verify dataset usability and annotation consistency, we perform zero-shot 6-DoF pose estimation using a state-of-the-art model on a representative subset of the dataset. Variations span solar azimuth, camera height, elevation, dust state, surface degradation, occlusion level, and terrain type. SynBag 1.0 establishes one of the first open, physically grounded datasets for 6-DoF-object perception in lunar construction and provides a scalable basis for future datasets incorporating soft-body simulation and robotic grasping. Full article

Microwave sintering technology is widely regarded as one of the most promising construction techniques for in situ resource utilization in lunar bases due to its high energy efficiency and unique heating mechanism. However, the extremely low-temperature environment on the lunar surface creates a transient temperature gradient of over a thousand degrees Celsius between the sintered body’s surface and its interior. This temperature difference induces significant thermal stress during the cooling process, leading to macroscopic surface cracks and even structural failure, which severely limits the engineering feasibility of this technology. To evaluate the surface integrity of lunar in situ sintered bodies and determine the safe processing window for microwave sintering, this study develops a multiphysics computational model that couples electromagnetic, thermal, and stress fields. The results show that when the cooling rate is below 15 °C/min, the surface stress remains below the material’s tensile strength threshold, effectively preventing crack formation. However, at a cooling rate of 16 °C/min, the surface stress exceeds this threshold, leading to crack initiation. Further analysis reveals that the cooling rate significantly affects the microstructure, with slow cooling maintaining a dense structure, while fast cooling promotes the formation of microcracks, particularly in regions with low Si/Al content. This study provides a reference for the microwave sintering process of lunar regolith and proposes a strategy of controlling the cooling rate below 15 °C/min. Full article

Diffraction-based velocity analysis is a key data interpretation technique in geophysical exploration, typically relying on the geometric characteristics, energy distribution, or propagation paths of diffraction waves. The hyperbola-based method is a classical strategy in this category, which extracts depth-dependent velocity (or dielectric properties) by correlating the hyperbolic shape of diffraction events with subsurface parameters for characterizing subsurface structures and material compositions. In this study, we propose a layer-stripping velocity analysis method applicable to ground-penetrating radar (GPR) and lunar-penetrating radar (LPR) data, with two main innovations: (1) replacing traditional local optimization algorithms with an intuitive parallelism check scheme, eliminating the need for complex nonlinear iterations; (2) performing depth-progressive velocity scanning of radargram diffraction signals, where shallow-layer velocity analysis constrains deeper-layer calculations. This strategy avoids misinterpretations of deep geological objects’ burial depth, morphology, and physical properties caused by a single average velocity or independent deep-layer velocity assumptions. The workflow of the proposed method is first demonstrated using a synthetic rock-fragment layered model, then applied to derive the near-surface dielectric constant distribution (down to 27 m) at the Chang’e-4 landing site. The estimated values range from 2.55 to 6, with the depth-dependent profile revealing lunar regolith stratification and interlayer material property variations. Consistent with previously reported results for the Chang’e-4 region, our findings confirm the method’s applicability to LPR data, providing a new technical framework for high-resolution subsurface structure reconstruction. Full article

As international lunar exploration shifts from mainly understanding the Moon to equally prioritizing its utilization, the requirement for highly similar lunar regolith simulants has grown. Current simulants, produced mainly by mechanical crushing and sieving, reproduce mechanical properties but lack space-weathered microstructures. However, this absence results in significant discrepancies in critical properties such as thermal conductivity and adsorption–desorption behavior, which undermine the reliability of ground-based resource utilization tests. To address this issue, this paper proposes a new preparation method for lunar regolith simulants, which simulates the micrometeorite impact process by utilizing the instantaneous high temperature, pressure, and high-velocity impact generated from the detonation of high-energy explosives in a sealed container. Preliminary experiments confirm that the method produces agglutinates, glass spherules, and porous structures resembling those in lunar regolith. The thermal conductivity of the modified simulant decreases significantly, approaching that of lunar regolith. Further refinement of the process, supported by quantitative 3D characterization, will enable the production of even more similar simulants, providing a reliable material foundation for lunar exploration, in situ resource utilization, and lunar construction activities. Full article

The establishment of a sustained human presence on the Moon is critically dependent on the ability to utilize local resources, primarily the production of oxygen for life support and propellant. The ROXY (Regolith to Oxygen and metals conversion) process is a molten salt electrolysis technology designed for this purpose. This paper presents an economic analysis of a ROXY pilot plant capable of producing over one ton of oxygen per year. We evaluate the economic viability by analyzing development, transportation, and operational costs against the potential revenue from selling oxygen and metals within a nascent lunar economy. A key aspect of this analysis is the perspective of an early customer in habitation life support systems preceding that of much higher propellant production demand. The analysis contextualizes this paradigm by recognizing that the primary economic driver for oxygen production is the larger future market for propellant; however, early life support demand may incentivize a paradigm-shift from Earth-based consumable resupply. Scenarios based on varying transportation costs and development timelines are evaluated to determine the internal rate of return (IRR) and time to break even (TTBE). The results indicate that the ROXY pilot plant is economically viable, particularly in near-term scenarios with higher transportation costs, achieving a positive IRR of up to 47.4% when both oxygen and metals are sold. The analysis identifies facility mass, driven by the robotics subsystem, as the primary factor for future cost-reduction efforts, concluding that ROXY is a technically and economically sound pathway toward sustainable lunar operations. Full article

The presented dataset contains spatial models of cones formed from lunar soil simulants. The cones were formed in a laboratory by allowing the soil to fall freely through a funnel. Then, the cones were measured using three methods: a high-precision handheld laser scanner (HLS), photogrammetry, and a low-cost LiDAR system integrated into an iPad Pro. The dataset consists of two groups. The first group contains raw measurement data, and the second group contains the geometry of the cones themselves, excluding their surroundings. This second group was prepared to support the calculation of the cones’ volume. All data are provided in standard 3D file format (.STL). The dataset enables direct comparison of resolution and geometric reconstruction performance across the three techniques and can be reused for benchmarking 3D processing workflows, segmentation algorithms, and shape reconstruction methods. It provides complete geometric information suitable for validating automated extraction procedures for parameters such as cone height, base diameter, and angle of repose, as well as for further research into planetary soil and granular material morphology. Full article

Space exploration is a major global focus, advancing knowledge and exploiting new resources beyond Earth. Bioinspired design—drawing principles from nature—offers systematic pathways to increase the capability and intelligence of space robots. Prior reviews have emphasized on-orbit manipulators or lunar rovers, while a comprehensive treatment across application domains has been limited. This review synthesizes bioinspired capability and intelligence for space exploration under varied environmental constraints. We highlight four domains: adhesion and grasping for on-orbit servicing; terrain-adaptive mobility on granular and rocky surfaces; exploration intelligence that couples animal-like sensing with decision strategies; and design methodologies for translating biological functions into robotic implementations. Representative applications include gecko-like dry adhesives for debris capture, beetle-inspired climbers for truss operations, sand-moving quadrupeds and mole-inspired burrowers for granular regolith access, and insect flapping-wing robots for flight under Martian conditions. By linking biological analogues to quantitative performance metrics, this review highlights how bioinspired strategies can significantly improve on-orbit inspection, planetary mobility, subsurface access, and autonomous decision-making. Framed by capability and intelligence, bioinspired approaches reveal how biological analogues translate into tangible performance gains for on-orbit inspection, servicing, and long-range planetary exploration. Full article

Developing autonomous technologies will enable humanity to considerably expand our lunar and space exploration capabilities. Along with the technical challenges of developing autonomous technologies, there is also the issue of trust—stakeholders are often resistant to their use for a variety of psychological reasons. Nevertheless, several successful methods for gradually building trust have been developed for both terrestrial and space applications. Relevant case studies provide insights on how trust is built for stakeholders when it comes to self-driving vehicles, Artificial Intelligence in aviation, space station operations, satellite rendezvous missions, and Mars rover surface operations. Based on these case studies, we propose a generalized method for building trust with stakeholders and have applied it to a lunar construction pathfinder mission currently in development. Metrics for assessing success criteria for autonomous systems are provided as a means to progress through the proposed phases of autonomy deployment. Full article