National Aeronautics and Space Administration plans to deploy astronauts to the Moon and construct sustainable habitat modules in collaboration with private companies and national space agencies worldwide. In situ resource utilization (ISRU) is indispensable for large-scale, long-term human lunar exploration. Water ice, which is one of the most precious resources, is believed to exist in the Moon's polar regions. Future plans include using it to maintain life support for astronauts and provide raw materials (H2 and O2) for rocket engines and fuel cells. Because the capture and delivery of ice are required to utilize water on the Moon, the following potentially reliable and efficient capture and delivery technologies for water ice, which are based on electrodynamic, electromagnetic, and mechanical vibration forces, are being developed. (1) The first is a capture and delivery system based on electrodynamic standing waves. When a high alternating voltage is applied to parallel screen electrodes, the alternating electrodynamic force is exerted on ice and regolith particles in contact with the lower electrode, and some agitated particles are captured after they pass through the openings of the upper screen electrode. The captured particles are transported between an array of zigzag electrodes activated by the application of high alternating voltage. (2) The second is a delivery system that utilizes an electrodynamic traveling wave. Three- or four-phase high voltage is applied to parallel line or ring electrodes to form an electrodynamic traveling wave. Meanwhile, regolith and ice particles are conveyed by traveling waves. Horizontal, curved, inclined, and vertical deliveries are realizable using this system. (3) The third is an electromagnetic delivery system based on the coil-gun principle, which considers the fact that lunar regolith particles are magnetic. A multistage coil-gun mechanism powered by a charged inductor-capacitor-resistor (LCR) circuit is used to deliver the regolith particles over long distances. (4) The fourth is a vibration delivery system. The vibration-conveyance mechanism, which is widely applied in terrestrial industries, is used to deliver regolith and ice particles. When the particles are on a plate or in a tube vibrated diagonally by actuators, the vibrating plate or tube is repeatedly propelled and conveys the particles diagonally in the forward direction. When the lower end of an inclined or vertically supported vibrating tube is immersed in a layer of regolith or ice particles, particles are introduced into the tube, and the friction force between the particles and the inner wall of the tube is used to convey the particles upward. This paper provides an overview of the recent progress of these unique technologies for efficient and reliable ISRU on the Moon.

The lunar environment is known to be characterized by complex interactions between plasma, the exosphere, dust, and the surface. However, our understanding of the environment is limited due to the lack of experimental evidence. Here, we propose a small, low-cost mission to characterize the dust and exosphere environment of the Moon. Named the Limb Pathfinder (LimPa), this is a proof-of-concept mission aimed toward understanding the coupling between plasma, dust, and tenuous neutral atmosphere. The LimPa mission was proposed to a call for the Small Mission to the Moon issued by European Space Agency in 2023. LimPa is designed to examine the dust exosphere above the lunar polar regions by using an utterly novel remote-sensing technique to measure the solar wind hydrogen atoms-the solar wind protons that are neutralized to hydrogen atoms. Its goals are (1) to detect for the first time the neutralized solar wind hydrogen produced by exospheric gas and levitated dust; (2) to measure the height profiles of the levitated dust and exospheric gas densities; and (3) to determine the emission mechanism of the horizon glow. Our baseline design of the LimPa mission is a 12U CubeSat. Three highly matured instruments are used: an energetic neutral atom camera, a proton sensor, and a camera system. The LimPa CubeSat is proposed to be inserted into a circular lunar polar orbit, with an altitude of 100 km as a baseline. The Sun-pointing attitude will allow measurements of neutralized solar wind that are produced by the exosphere and dust grains above the polar regions. The nominal lifetime is for 3 months as a pathfinder mission. The LimPa mission will open a new window to remote characterization of the lunar dust exosphere environment above the poles, and will demonstrate that this monitoring can be achieved with a simple and low-cost instrument system and spacecraft operation. The concept to be proven by the LimPa mission will enable long-term monitoring of the fragile dust exosphere environment, which substantially impacts on lunar exploration and will be significantly altered by human activities.

Lidar technology plays a pivotal role in lunar exploration, particularly in terrain mapping, 3D topographic surveying, and velocity measurement, which are crucial for guidance, navigation, and control. This paper reviews the current global research and applications of lidar technology in lunar missions, noting that existing efforts are primarily focused on 3D terrain mapping and velocity measurement. The paper also discusses the detailed system design and key results of the laser altimeter, laser ranging sensor, laser 3D imaging sensor, and laser velocity sensor used in the Chang'E lunar missions. By comparing and analyzing similar foreign technologies, this paper identifies future development directions for lunar laser payloads. The evolution towards multi-beam single-photon detection technology aims to enhance the point cloud density and detection efficiency. This manuscript advocates that China actively advance new technologies and conduct space application research in areas such as multi-beam single-photon 3D terrain mapping, lunar surface water ice measurement, and material composition analysis, to elevate the use of laser pay-loads in lunar and space exploration.

Leading national space exploration agencies and private enterprises are actively engaged in lunar exploration initiatives to accomplish manned lunar landings and establish permanent lunar bases in the forthcoming years. With limited access to lunar surface materials on Earth, lunar regolith simulants are crucial for lunar exploration research. The Chang'e-5 (CE-5) samples have been characterized by state-of-the-art laboratory equipment, providing a unique opportunity to develop a high-quality lunar regolith simulant. We have prepared a high-fidelity PolyU-1 simulant by pulverizing, desiccating, sieving, and blending natural mineral materials on Earth based on key physical, mineral, and chemical characteristics of CE-5 samples. The results showed that the simulant has a high degree of consistency with the CE-5 samples in terms of the particle morphology, mineral and chemical composition. Direct shear tests were conducted on the simulant, and the measured internal friction angle and cohesion values can serve as references for determining the mechanical properties of CE-5 lunar regolith. The PolyU-1 simulant can contribute to experimental studies involving lunar regolith, including the assessment of interaction between rovers and lunar regolith, as well as the development of in-situ resource utilization (ISRU) technologies. (c) 2024 Published by Elsevier B.V. on behalf of China University of Mining & Technology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Lunar exploration is of significant importance in the development and utilization of in situ lunar resources, water ice exploration, and astronomical science. In recent years, ground-based radar (GBR) has gained increasing attention in the field of lunar exploration due to its flexibility, low cost, and penetrating capabilities. This paper reviews the scientific research on lunar exploration using GBR, outlining the basic principles of GBR and the progress made in lunar exploration studies. Our paper introduces the fundamental principles of lunar imaging using GBR and systematically reviews studies on lunar surface/subsurface detection, the dielectric properties inversion of the lunar regolith, and polar water ice detection using GBR. In particular, the paper summarizes the current development status of the Chinese GBR and forecasts future development trends in China. This review will enhance the understanding of lunar exploration results using GBR radar, systematically demonstrate the main applications and scientific achievements of GBR in lunar exploration, and provide a reference for GBR radar in future lunar exploration missions.

Water and other volatiles are present in the permanently shadowed region of the moon. Quantitative analysis of the content is of great significance for lunar resource assessment and geological evolution. However, no detector has yet carried out in situ analysis on the moon, and quantitative sampling and low-power thermal extraction of lunar regolith are also difficult. Thus, a systematic method is proposed to realize quantitative sampling & low power thermal extraction of lunar regolith that detects the abundances of volatiles more accurately. Considering the requirements of the amount and particle size of the regolith, a sampler with specific structure and motions is designed to quantitatively collect some lunar regolith. After that, induction heating is applied to heat the sampler and indirectly increase the temperature of the internal lunar regolith for volatile thermal extraction. The results demonstrate that this sampling method can achieve high-quality quantitative sampling. Moreover, the sampler and sampled regolith can be heated to the desired temperature with low power consumption. This work offers a feasible solution for the lunar volatile exploration of Chang'E-7.

The Imaging InfraRed Spectrometer (IIRS) on board Chandrayaan-2 has been providing high spatial and spectral resolution observations of the lunar surface in 256 spectral bands (0.7-5 mu m) since September 2019. It is primarily intended for mineral mapping and identifying hydration features on the lunar surface using reflectance spectra in the range of 0.7-3.2 mu m. Here, we have used the IIRS observations in the 3-5 mu m range to retrieve daytime lunar surface temperature and spectral emissivity using an optimal estimation theory -based retrieval algorithm. The surface temperature is retrieved at every pixel, while spectral emissivity is retrieved at every third pixel of the hyperspectral image. The mean uncertainty of the retrieved spectral emissivity varies from 0.04 to 0.08, while for surface temperature, it is about 3.5 K. The retrieved spectral emissivity is found to be in close agreement with the emissivity of the Apollo -16 return soil samples.

The subject of the work is the analysis of satellite data in the database LROC: QuickMap. The article focuses on water ice deposits which could be converted into hydrogen or oxygen, among other things, and later used as a rocket fuel. The distribution of water ice deposits on the Moon is presented and a micro-trap on the Moon's south pole is proposed, which in the future could be an object for the exploration of water ice. An exit and descent route to the crater floor for the rover was also proposed, considering the degree of insolation and the degree of slope of the crater walls.

Identifying the best technique for extracting water ice deposits in permanently shadowed regions at the lunar poles will be crucial in determining how successful a long-term or permanent settlement at these locations will be for future scientific and technology missions. This study uses a low-power microwave heating method to extract water from icy lunar simulants. Samples of lunar highland and mare simulants at different water contents (3-15 wt %) were heated using 250 W, 2.45 GHz microwaves. A maximum of 67 +/- 5% [2SD] of the water was extracted during heating runs of 25 min. Water was extracted more efficiently from the highland simulant than from the mare simulant. A significant reason for the different efficiency of water extraction in icy lunar simulants was the differing porosity of the samples made from different simulants. Pore space filled with ice leads to a reduced contact area between grains and an increased area of free ice, which causes poor heating performance. The results indicated that differences in chemical composition between the simulants had a negligible effect on water extraction, as the contact area between grains seems to dominate water extraction. This study found that low-power microwave heating is an effective technique for extracting water from cryogenic Icy simulants. It was also found that using a simple input energy principle (Input Energy = Absorbed Power x Heating Time) to es-timate the additional heating time was sufficient to overcome inefficient heating due to differing absorbed powers. For undersaturated samples, microwave heating was an efficient heating mechanism, but is less efficient for saturated samples where alternative heating methods may be more efficient at melting free ice before employing microwave heating.

The recent discovery of water ice in the lunar polar shadowed regions (PSRs) has driven interest in robotic exploration, due to its potential utilization to generate water, oxygen, and hydrogen that would enable sustainable human exploration in the future. However, the absence of direct sunlight in the PSRs poses a significant challenge for the robotic operation to obtain clear images, consequently impacting crucial tasks such as obstacle avoidance, pathfinding, and scientific investigation. In this regard, this study proposes a visual simultaneous localization and mapping (SLAM)-based robotic mapping approach that combines dense mapping and low-light image enhancement (LLIE) methods. The proposed approach was experimentally examined and validated in an environment that simulated the lighting conditions of the PSRs. The mapping results show that the LLIE method leverages scattered low light to enhance the quality and clarity of terrain images, resulting in an overall improvement of the rover's perception and mapping capabilities in low-light environments.