Distinguishing the origin of lunar water ice requires in situ isotopic measurements with high sensitivity and robustness under extreme lunar conditions; however, challenges such as uncertain water contents and isotopic fractionation induced by regolith particles restrict isotopic analysis. Herein, we present a miniaturized tunable diode laser absorption spectrometer (TDLAS) developed as the core prototype for the Chang'E-7 Lunar Soil Water Molecule Analyzer (LSWMA). The wavelength range of the instrument is 3659.5-3662.0 cm-1, and the system integrates a Herriott cell for stable multi-isotope (H2 16O, H2 18O, H2 17O, and HD16O) detection and employs regolith samples of known isotopic experiments to quantify adsorption-induced fractionation. Performance evaluations demonstrated a dynamic water detection range of 0.01-2 wt % and isotope precision up to 1.3 parts per thousand for delta D (30.5 s), 0.77 parts per thousand for delta 18O (36 s), and 0.75 parts per thousand for delta 17O (21.5 s) with extended averaging. Repeated injections of three types of standard water revealed a volume-dependent deviation (Delta delta D up to -59.5 parts per thousand) attributed to multilayer adsorption effects, while simulated lunar soil experiments identified additional isotopic fractionation (Delta delta D up to -12.8 parts per thousand) caused by particle binding. These results validate the ability of the spectrometer to resolve subtle isotopic shifts under lunar conditions, providing critical data for distinguishing water origins and advancing future resource utilization strategies.

An increasing amount of evidence indicates that lunar water ice exists in permanently shadowed regions at the poles and will soon become an important resource for lunar exploration. However, the water ice content and distribution are still uncertain. We report a new 70-cm-wavelength radar image of the lunar south pole obtained by an Earth-based bistatic radar system consisting of the Sanya incoherent scatter radar (SYISR) and the five-hundred-meter aperture spherical radio telescope (FAST). The upper limit of water ice content (0 wt.%-6 wt.%) and its potential distribution are determined from a radar circular polarization ratio (CPR) map by considering the coherent backscatter opposition effect (CBOE) of water ice and ignoring the contribution of roughness to the CPR. This result is advantageous for future lunar exploration missions. (c) 2025 The Authors. Published by Elsevier B.V. and Science China Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

This paper presents an ultrasonic sampling penetrator with a staggered-impact mode, which has been developed for the extraction of lunar water ice. A comparison of this penetrator with existing drilling and sampling equipment reveals its effectiveness in minimizing disturbance to the in situ state of lunar water ice. This is due to the interleaved impact penetration sampling method, which preserves the original stratigraphic information of lunar water ice. The ultrasonic sampling penetrator utilizes a single piezoelectric stack to generate the staggered-impact motion required for the sampler. Finite element simulation methods are employed for the structural design, with modal analysis and modal degeneracy carried out. The combined utilization of harmonic response analysis and transient analysis is instrumental in attaining the staggered-impact motion. The design parameters were then used to fabricate a prototype and construct a test platform, and the design's correctness was verified by the experimental results. In future sampling of lunar water ice at the International Lunar Research Station, the utilization of the ultrasonic sampling penetrator is recommended.

This study investigates the detectability of a putative layer of regolith containing water ice in the lunar polar regions using ground penetrating radar (GPR). Numerical simulations include realistic variations in the relative permittivity of the lunar regolith, considering both density and, for the first time, the effects of temperature on permittivity profiles. We follow the case of previous theoretical studies of water migration, which suggest that water ice accumulates at depths ranging from a few centimeters to tens of centimeters, appropriate depths to explore using GPR. In particular, frequency-modulated continuous wave (FMCW) radar is well-suited for this purpose due to its high range resolution and robust signal-to-noise ratio. This study evaluates two scenarios for the presence of lunar water ice: (1) a layer of regolith containing water ice at a depth of 5 cm, with a thickness of 5 cm, and (2) a layer of regolith containing water ice at a depth of 20 cm, with a thickness of 10 cm. Our computational results show that FMCW GPR, equipped with a dynamic range of 90 dB, is capable of detecting reflections from the interfaces of these layers, even under conditions of low water ice content and using antennas with low directivity. In addition, optimized antenna offsets improve the resolution of the upper and lower interfaces, particularly when applied to the surface of ancient crater ejecta. This study highlights the critical importance of understanding subsurface density and temperature structures for the accurate detection of water-ice-bearing regolith layers.

Earth-based radar (EBR) is an important type of remote sensing instrument for planetary observation. EBR takes advantages in large-scale imaging swath, high repeatability, great flexibility, and so on. The upcoming 233-MHz-frequency European Incoherent Scatter Scientific Association (EISCAT) 3-D radar system will provide important features to lunar observation as introduced in this study. EISCAT_3D (E3D) radar is a powerful multistatic radar system. The 1.3-m wavelength wave of E3D can penetrate deeper, about 30 m below the lunar average surface, which can reach the second layer, i.e., layer of ejecta. E3D radar supports dual/quadrature polarimetry, which gives it good flexibility and lower ambiguity in the inference of scatter's properties. Also, there is less ambiguity in scattering regimes between icy and nonicy scatters for 1.3-m wavelength than for shorter wavelengths as given from the simulation results. Besides, the high topographic resolution (which requires forming interferometric baselines with distant telescope antennas) of E3D radar along with its penetration depth makes it possible for detection of sublunarean cavities by signatures of depression. As a whole, the 1.3-m wavelength 3-D polarimetric imaging of the Moon by E3D radar, on a spatial resolution of about 200 m, will be valuable for obtaining new information about the geology and subsurface structure of the Moon and can be used in search of buried water ice, sublunarean cavity, and so on. Furthermore, we envision the collaboration of E3D radar with large telescope antennas in China, including Daocheng Solar Radio Telescope (DSRT) and Mingantu spectral radioheliograph (MUSER) for better imaging ability and detectivity.

Investigation on lunar water ice simulant under impact load is essential for future lunar exploration in the south polar region of the moon. In this paper, the impact dynamic properties of lunar water ice simulant are investigated by using an FDM-DEM coupling method, and the effectiveness of the method and the rationality of parameters are verified by comparing simulation results with experimental results. The results indicate that the FDM-DEM coupling method can effectively simulate the impact dynamic properties of lunar water ice simulant, and find that the lunar water ice simulant exhibits strain rate enhancement effect, the enhancement effect is more pronounced with increasing water content. Furthermore, the quantitative damage degrees and visualized failure patterns are obtained, the damage degrees and failure patterns of lunar water ice simulant show a strong dependence on the water content and impact velocity. But when the water content is 5%, the damage degree is close to 95% and basically no longer affected by impact velocity. (c) 2024 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

In the context of space exploration, the in-situ utilization of lunar water ice holds principal significance. A variety of techniques have been suggested for water ice mining. However, the impact of mining equipment structure on water ice extraction has been rarely reported. Here, we used numerical simulations to study the impact of drilling-based mining equipment structure on water extraction from icy soil, by comparing two designs: Corer and Auger. The impact of water ice on deep lunar drilling missions was explored. The results showed that the mining equipment structure significantly affects vapor flow, phase transitions, and water ice extraction efficiency. The Auger's design allows for higher water vapor content and enhanced heat transfer within the icy soil, while the Corer's design reduces vapor flow and performs better during the initial mining stage. It is believed that this work will provide theoretical guidance for designing high-performance mining equipment in further lunar water ice utilization. We also highlighted the potential role of water ice in lunar soil for enhancing heat dissipation in deep drilling missions, protecting the drill bit from potential damage due to elevated temperatures. The insights gained from this study offer valuable contributions to the design of drilling tools for future lunar missions and the exploration of other icy celestial bodies.

Lunar in-situ water ice utilization is considered an essential part of the future construction of Lunar Bases. However, the thermal conductivity of lunar regolith without water ice is extremely low, which seriously hinders the thermal mining of lunar water ice. In this study, we proposed a novel approach to optimize the energy ef-ficiency of water ice thermal mining. In this method, a constant temperature heat source with a heating tem-perature selected according to the particle size of water ice was used to slow down the reduction rate of the thermal conductivity of icy soil. Our simulation results showed that the relatively high mining temperature led to the rapid sublimation of water ice near the heat source, reducing the thermal conductivity of the icy soil and the energy efficiency.A relatively low mining temperature decreases the sublimation speed of water ice and reduces energy effi-ciency. The particle size of water ice determined the decreasing rate of thermal conductivity of icy soil, thus affecting its optimum heating temperature. Using a constant temperature heat source at the optimal heating temperature, the energy efficiency of water ice mining could be increased by several orders of magnitude compared with constant power heating.

This paper explores the impacts of a potential royalty mechanism by considering the effects of different royalty and tax rates on the economics of a hypothetical commercial lunar ice mining project. The study also examines the conceivable benefits that could be generated from a royalty regime from a global perspective and considers the possible impacts of royalties on operational decision making in a com-mercial lunar ice mining context. There has been substantial debate since the signing of the Outer Space Treaty in 1967 regarding how to ensure the international community benefits from the commercial exploitation of space resources, should these activities eventuate. This includes the recent initiative by the Legal Subcommittee of the UN Committee on the Peaceful Uses of Outer Space to establish a Working Group to explore potential models for a legal framework to govern space resource activities. No formal proposal to include a royalty mechanism has yet been made; however, it is apparent that part of the mandate of the Committee on the Peaceful Uses of Outer Space Legal Subcommittee could be to explore the issue of benefit sharing, and it is possible that a royalty mechanism or something similar could ul-timately be proposed. After considering the impact of royalties on a hypothetical lunar ice mining project, this paper finds that royalties, in particular ad valorem royalties, could have a meaningful impact on the economics and operational parameters of a commercial lunar ice mining project, in turn potentially impacting the ability to raise the funding required to develop such projects. The study also finds that under plausible scenarios, the benefits generated on a per capita basis would be negligible, even assuming significant industry growth rates over 50 years. The study, therefore, concludes that the rationale for imposing a royalty mechanism on space resource activities for the purposes of benefit sharing through direct monetary distribution to recipients would need to be carefully examined should such a royalty mechanism ever be proposed.& COPY; 2022 Elsevier Ltd. All rights reserved.

Commercial lunar resource extraction activities could become a reality in the mid to long term. Under the existing Outer Space Treaty, there is ambiguity regarding the legal context within which such activities could occur. The Artemis Accords, signed in 2020, are proposed as a mechanism by which space resource extraction activities could take place, with a key proposal of the Accords being the use of Safety Zones to facilitate lunar resource extraction. Whilst the use of Safety Zones is ostensibly proposed for small scale In Situ Resource Utilisation (ISRU) activities focussed on lunar water production, messaging around the Artemis Accords has indicated that there may be an intent to use them to set precedent for longer term, larger scale commercial resource activity. This article explores the practicability of using Safety Zones for large scale commercial lunar resource extraction from the perspective of the commercial entities that could undertake such activities. Conceptual long term demand for water sourced from ice contained in the lunar Permanently Shadowed Regions (PSRs) is derived, and the surface area required to produce sufficient water to meet this market demand determined. Due to the potential characteristics of water ice occurrence in the lunar PSRs, the footprint of operations could be substantial, and virtually without precedent in the terrestrial extractive resource industries. The article concludes that the use of the Safety Zones proposed in the Artemis Accords could be impractical for the governance of large scale commercial lunar resource production. It is suggested that whilst small scale ISRU activities take place under the auspices of the Artemis Accords, efforts are continued to develop a multilateral governance framework acceptable to both the international community and to the commercial sector for the potential large scale development of lunar resources.(c) 2022 Elsevier Ltd. All rights reserved.