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The accurate measurement of inter-satellite distances is fundamental to the successful operation of distributed spacecraft missions, facilitating diverse applications ranging from scientific exploration to navigation and communication. This study comprehensively overviews applications requiring inter-satellite tracking by analyzing 44 multi-spacecraft missions. These missions are divided into seven categories based on their use of inter-satellite distance measurements. Each category necessitates varying levels of accuracy, prompting the utilization of distinct tracking methods. The analysis reveals that missions near Earth typically rely on Global Navigation Satellite Systems measurements, achieving millimeter-level accuracy, while lunar missions opt for radio ranging for centimeter-level accuracy. Inter-satellite Laser Ranging Interferometry emerges as the preferred method for missions demanding exceptionally high accuracy (nanometer to picometer range), such as those dedicated to gravitational wave detection and gravimetry. Notably, the analysis identifies a burgeoning trend towards the adoption of Inter-satellite Laser Transponder Ranging, capable of achieving sub-millimeter accuracy. Furthermore, this work proposes a novel concept: integrating inter-satellite ranging with Laser Communication Terminal (LCTs), either to substitute for existing tracking methods or to enhance measurement accuracy within established frameworks. However, its full potential rests upon the successful adaptation of existing LCTs for ranging functionality without compromising data rates. Future research will play a critical role in quantifying achievable ranging performance by characterizing systematic errors within LCTs. [ABSTRACT FROM AUTHOR]

The safety of lunar landing sites directly impacts the success of lunar exploration missions. This study develops a data-driven predictive model based on machine learning, focusing on engineering safety to assess the suitability of lunar landing sites and provide insights into key factors and feature representations. Six critical engineering factors were selected as constraints for evaluation: slope, elevation, roughness, hillshade, optical maturity, and rock abundance. The XGBoost model was employed to simulate and predict the characteristics of landing areas and Bayesian optimization was used to fine-tune the model's key hyperparameters, enhancing its predictive performance. The results demonstrate that this method effectively extracts relevant features from multi-source remote sensing data and quantifies the suitability of landing zones, achieving an accuracy of 96% in identifying landing sites (at a resolution of 0.1° × 0.1°), with AUC values exceeding 95%. Notably, slope was recognized as the most critical factor affecting safety. Compared to assessment processes based on Convolutional Neural Networks (CNNs) and Random Forest (RF) models, XGBoost showed superior performance in handling missing values and evaluating feature importance accuracy. The findings suggest that the BO-XGBoost model shows notable classification performance in evaluating the suitability of lunar landing sites, which may provide valuable support for future landing missions and contribute to optimizing lunar exploration efforts. [ABSTRACT FROM AUTHOR]

The article examines the relationships and dynamics within a crew during a 17-day simulated space flight, focusing on risks such as decreased morale and communication breakdowns. Topics include the "third quarter phenomenon," crew subgroup formation, and the role of mission control support. It highlights the impact of crew composition on interpersonal dynamics and overall mission effectiveness.

Determining water concentrations in the polar regions of the Moon is one of the priority tasks of a number of space missions and, in particular, the Luna-27 mission. The complex of scientific equipment of the Luna-27 spacecraft includes time-of-flight laser ionization mass spectrometer LASMA-LR, the main task of which is to analyze the elemental composition of the regolith at the landing site. The design and configuration of the flight instrument is adapted for the analysis of regolith and was not originally intended for the study of volatile compounds. However, due to the importance of determining the water content in regolith, we reviewed some approaches to analyzing samples during lunar missions and assessed the applicability of LASMA-LR and the laser ionization mass spectrometry method in general for identifying water in regolith. It has been established that using this instrument it is possible to detect water in regolith, including determining its state (chemically bound and unbound water). Moreover, the conditions for sampling the regolith and delivering it to the soil receiving device of the instrument are critically important for the analysis, since under the conditions of the lunar surface, sublimation of ice is possible before the samples are analyzed. This technique has advantages over some other methods of analyzing water and/or ice used in space experiments, and can be used in the study of a number of planets and bodies of the Solar System. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive framework for designing in-space propulsion systems, integrating four criteria: global propulsive performance, environmental impact, cost efficiency, and architectural reliability. The study focuses on the emerging class of Orbital Transfer Vehicles to illustrate the application of this method. By examining the synergistic potential of OTVs and greener propellants, the paper addresses different mission scenarios, including LEO, GEO, and lunar missions, with both scientific and commercial objectives. The proposed framework aims to go beyond traditional cost-centric approaches, offering a more complete evaluation method for early design phases. A case study comparing three liquid bipropellant options, pressure-fed MON-3/MMH, 98%-HTP/RP-1, and self-pressurizing N 2 O/Ethane, demonstrates the utility of the tool. Findings suggest that scientific missions benefit most from 98%-HTP/RP-1, while traditional propellants remain preferable for cost-driven commercial missions to GEO and the Moon, though greener alternatives are competitive for less demanding LEO missions. This innovative framework aims to guide the selection of propulsion systems to achieve greener space missions, aligning traditional performance figures with environmental responsibility. • The transition towards greener propellants introduces new requirements beyond pure performance. • A holistic early-design framework is proposed to identify optimal future propulsive solutions. • This approach integrates environmental impact and reliability alongside traditional cost-efficiency and performance targets. • Greener propellants demonstrate a competitive advantage over legacy ones for specific space mission profiles. [ABSTRACT FROM AUTHOR]

The advancement in extraterrestrial exploration has highlighted the crucial need for studying how the human cardiovascular system adapts to space conditions. Human development occurs under the influence of gravity, shielded from space radiation by Earth's magnetic field, and within an environment characterized by 24-hour day-night cycles resulting from Earth's rotation, thus deviating from these conditions necessitates adaptive responses for survival. With upcoming manned lunar and Martian missions approaching rapidly, it is essential to understand the impact of various stressors induced by outer-space environments on cardiovascular health. This comprehensive review integrates insights from both actual space missions and simulated experiments on Earth, to analyze how microgravity, space radiation, and disrupted circadian affect cardiovascular well-being. Prolonged exposure to microgravity induces myocardial atrophy and endothelial dysfunction, which may be exacerbated by space radiation. Mitochondrial dysfunction and oxidative stress emerge as key underlying mechanisms along with disturbances in ion channel perturbations, cytoskeletal damage, and myofibril changes. Disruptions in circadian rhythms caused by factors such as microgravity, light exposure, and irregular work schedules, could further exacerbate cardiovascular issues. However, current research tends to predominantly focus on disruptions in the core clock gene, overlooking the multifactorial nature of circadian rhythm disturbances in space. Future space missions should prioritize targeted prevention strategies and early detection methods for identifying cardiovascular risks, to preserve astronaut health and ensure mission success. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The lunar surface undergoes various space weathering and impact processes, which shape the regolith and expose boulders. Using high-resolution Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera imagery and associated Digital Elevation Models, we investigate regolith thicknesses and boulder densities at the four candidate landing sites of the Emirates Lunar Mission Rashid-1 rover: the floor-fractured crater Atlas and the Sinus Iridum, Oceanus Procellarum and Lacus Somniorum maria. The regolith thickness is estimated using the small crater morphology method, by mapping 3413 central mound, flat-bottomed, concentric craters (<350 m in diameter). Boulders were counted manually and compared with LRO Diviner rock abundance and mini-RF Circular Polarisation Ratio global maps. There is no obvious correlation between the site's age, average regolith thickness and boulder density. The "Depth-Age hypothesis" is not confirmed here: Atlas (3.8 Gyr) has the thinnest regolith (median: 1.2 m), Procellarum (1.9 Gyr) and Somniorum (3.7 Gyr) have similar thicknesses (1.7 m and 1.8 m respectively), and the regolith in Iridum (3.4 Gyr) is the thickest (2.9 m). The estimated regolith thickness is highly variable laterally within the landing ellipses. Boulder fields in the landing areas are well-correlated with higher Diviner rock abundance values, and with locally thicker patches of regolith. The relatively thin regolith in Atlas could be related to its complex geology involving multiple volcanic episodes. Orbital estimates of regolith thickness and boulder distribution remain key for landing safety and trafficability assessments during mission preparations, and bring key insights into the local history of the regolith through crater morphologies. [ABSTRACT FROM AUTHOR]

OMOTENASHI is a 6U CubeSat launched by the first NASA SLS rocket. Its mission was to demonstrate that a CubeSat can make a semi-hard landing on the Moon. Tight resource constraints make it difficult to mount a heater and a radiator in a CubeSat, so passive thermal control is a prominent design feature of OMOTENASHI that resolves the technical difficulty. In November 2019, a thermal vacuum test was conducted. This paper discusses the thermal design and the test results. OMOTENASHI was launched by SLS rocket on November 16, 2022. After the SLS rocket separation, OMOTENASHI's attitude control malfunctioned so it could not generate power from its solar cells. Eventually, communications were lost and have not been restored. Brief telemetry data confirmed that the temperature monitor functioned correctly for 30 min. This paper reports the flight results of the thermal status during the first ground station pass. Also, a comparison between the analysis model and telemetry data is shown. Finally, based on its estimated trajectory, the future thermal profile of the spacecraft and the result of the search operation are discussed. • OMOTENASHI was developed as the world's smallest moon lander that was launched by a NASA SLS rocket. • Passive thermal control design without a thermal controller is adopted by using a white paint and a graphite sheet. • Passive thermal control design can be utilized for future CubeSat missions under tight resource constraints. • This paper introduced the experiment and analysis method that achieves the thermal design for lunar missions by CubeSat. • The flight data after the launch of the SLS rocket showed the feasibility of this passive thermal control design. [ABSTRACT FROM AUTHOR]

Lunar missions are currently experiencing a significant surge in popularity, presenting expansive opportunities for further exploration and development. To thoroughly explore the design margins and potential of lunar landers, and to foster the development of overall designs driven by comprehensive performance objectives, it is crucial to conduct optimization design considering the coupling between key disciplines such as trajectory and propulsion. Considering the significant increase in computational complexity caused by conducting trajectory/propulsion integrated design optimization, the analytical target cascading method is employed to hierarchically decompose and coordinate optimization of the complex systems. This article presents a phased soft-landing strategy on the manned lunar lander propelled by hybrid rocket motors, utilizing powered explicit guidance and Apollo powered descent guidance, and proceeds with the trajectory/propulsion integrated design optimization involving diverse grain shapes and feed systems. This optimization process is separately undertaken utilizing multidisciplinary feasible method and analytical target cascading method. The analysis reveals that integrating trajectory and propulsion considerations into the optimization process facilitates a 5 % reduction in the overall mass relative to optimizations constrained solely by velocity increment and lack comprehensive trajectory design considerations. This highlights the profound impact of trajectory requirements on propulsion system design and the advantages of powered explicit guidance laws in minimizing fuel consumption. Crucially, the use of analytical target cascading achieves the better optimization results, and significantly reduces subsystem evaluation times, enhancing operational efficiency by 48 %, demonstrating the advantage in handling complex, large-scale systems. On another level, with different β values, the Mean Relative Error of the target values for the three schemes obtained by the analytical target cascading method is 0.0016, indicating good stability and strong robustness. The practical exploration in this article provides methods and frameworks for high-performance optimization design of complex aerospace mission profiles in the future. • The trajectory/propulsion integrated design optimization is conducted. • The two-phase guidance strategy for lunar lander descent is proposed. • Based on the strategy, the analytical target cascading-decomposed framework is set. • The influence of trajectory and propulsion coupling on overall design is revealed. • The optimization effectiveness, convergence rate, and robustness of the ATC is shown. [ABSTRACT FROM AUTHOR]

This study aims to determine the optimal design and ascent trajectory for a single-stage hybrid rocket in the context of a lunar ascent mission, with the objective of reaching a 100 km circular orbit on the Moon equatorial plane. A multi-disciplinary optimization problem is formulated, integrating flight design variables and launch vehicle design variables to achieve the best mission scenario. A zero-dimensional internal ballistics model is employed to estimate key parameters such as thrust, mass flow rate, and gross mass of the hybrid rocket, while a three-degree of freedom dynamical model is utilized to simulate the ascent trajectory. The resulting integrated optimization problem is solved using an in-house heuristic algorithm that combines particle swarm and genetic algorithms. Two propellant combinations, liquid oxygen/paraffin-wax and hydrogen peroxide (90%)/high-density polyethylene, are evaluated, considering both their performance in the integrated system and the feasibility of the proposed mission. After conducting a sensitivity analysis to investigate the influence of particle count in the optimization process, results for both propellant combinations are presented. While paraffin and oxygen provide the highest payload ratio, hydrogen peroxide and polyethylene entail a more feasible and flexible design for a lunar mission. • Multi-disciplinary optimization of single-stage hybrid rocket for lunar ascent. • In-house hybrid heuristic optimization algorithm. • Evaluation of LOX/Wax and H2O2(90%)/HDPE. • LOX and H2O2 offer similar performance in terms of payload ratio. [ABSTRACT FROM AUTHOR]

In this study, we examine the Russian automatic lunar missions "Luna-25," "Luna-26," and the scientific objectives and landing site of the "Luna-27″ spacecraft. The landing of "Luna-27″ is planned directly in the South Polar region, which, due to ballistic and engineering requirements, is confined to a sector extending from 51°E to 1°W in longitude and from 83°S to 79°S in latitude. This area is characterized by complex terrain, and to identify suitable landing territories, a suitability map has been created that takes into account the distribution of slopes, the degree of illumination, and visibility of Earth. A total of five sites measuring 30 × 15 km (landing ellipse) within the considered region meet such scientific and technical requirements as slope distributions of less than 7–10°, sunlight illumination of more than 35 %, and Earth visibility of more than 50 %. All landing sites are ranked by priority from 1 to 5 depending on the content of water equivalent of hydrogen (WEH) in the lunar soil. Site №1, by its characteristics, is considered the best and may be chosen as the primary landing site, while sites №2 and №3 could serve as backups. It is demonstrated that with increased landing precision, with a deviation probability from the given point up to 0.5 km, the number of suitable landing sites satisfying primarily scientific rather than engineering-technical safety criteria, which are also inherently met, significantly increases. • Landing zone: 51°E to 1°W, 83°S to 79°S. • Map identifying suitable area for spacecraft landing. • Slope distribution, Sun illumination, Earth visibility, water-hydrogen content. • Only five sites (30 × 15 km ellipsoids) meet criteria. • Landing accuracy crucial for meeting scientific needs. [ABSTRACT FROM AUTHOR]

There are always uncertainties in practical engineering, and the design of the optimal Earth-Moon trajectory under uncertainties significantly reduces flight risk for the manned lunar exploration mission (MLEM). This paper proposes an interval programming method to optimize the trans-lunar trajectory under interval uncertainties. Firstly, the influence of the trans-lunar injection uncertainties (TLI) is investigated, finding that the reached orbit at the perilune is very sensitive to the impulse errors at TLI. Then, the design methods of the Earth-Moon trajectory and the trajectory correction maneuver (TCM) are presented. Based on the mathematical tool of the interval possibility degree, the interval programming model is built to transform the uncertain optimization problem into a deterministic one, and then a multi-layer optimization scheme is proposed to solve it. The uncertain objectives and constraints' interval bounds are calculated in the inner loop, and the design variables are searched and optimized in the outer loop. The proposed method is used to design the Earth-Moon trajectories of both manned and unmanned spacecraft. The designed trajectories are insensitive to the uncertainties and are validated by the Monte Carlo simulations. [ABSTRACT FROM AUTHOR]

Silicic lithologies on planetary surfaces indicate magmatic evolutionary processes in their interiors. The Wolf crater complex within Mare Nubium on the Moon is one such silicic construct associated with a high thorium anomaly. This study integrates morphological, compositional, chronological and gravity anomaly analyses of high‐resolution data from various lunar missions to establish this construct as a silicic volcanic caldera. Lobate flows with steeply sloping fronts indicate that the crater rims comprise high‐viscosity silicic lavas, while the structurally controlled inner crater walls suggest caldera collapse triggered by magma depletion. In the crater rims, low Christiansen Feature position values reaffirm the presence of silicic lithologies, consistent with the low gravity anomaly signature beneath the complex, while spectroscopic data reveal low mafic mineral abundances and negligible hydration features. Chronological analyses yield silicic volcanism ages coeval with surrounding mare basalts (3.8–3.6 Ga), while intra‐caldera basalts have 2.36–2.02 Ga ages, indicating prolonged magmatism in this region. Melting of suitable crustal protoliths like alkali gabbronorite/monzogabbro/troctolite by basaltic underplating is inferred to have generated silicic magmas that formed the Wolf volcanic complex, instead of basaltic magma fractionation or silicate‐liquid immiscibility processes. Large impacts during the Late Heavy Bombardment may have enhanced partial melting of the mantle and created crustal fractures that facilitated the ascent of viscous silicic melts through the lunar crust. Contemporaneous existence of suitable protoliths and adequate crustal pathways for magma ascent may have controlled silicic volcanism on the Moon, and can explain the sporadic occurrence and overlapping ages of the lunar silicic constructs. Plain Language Summary: Understanding how evolved silica‐rich rocks formed on the Moon can shed light on the magmatic differentiation and thermal evolution of the lunar mantle. Here, we study one such silicic region called the Wolf crater complex on the lunar nearside using compositional and morphological evidence from high‐resolution images and remotely sensed data. Spectroscopic and gravity studies confirm that the rocks have a silicic composition but with negligible water content. The complex is characterized as a silicic volcanic crater/caldera that was later filled with basalt. Formation of the volcano and its collapse to form the caldera were controlled by pre‐existing structures. Ages calculated by crater‐counting methods suggest that magmatic activity persisted in this region for ∼2 billion years. These apparently dry silicic melts could not have been derived by fractionation or unmixing of basaltic magmas. Instead, large impacts in the region may have thinned the crust, enhancing partial melting of the underlying mantle and facilitating basaltic underplating of the crust. Melting of appropriate protoliths (alkali gabbronorite/monzogabbro/troctolite), where present in the underplated crust, may generate viscous silicic melts whose ascent is then facilitated by impact‐generated fractures. This model explains why lunar silicic constructs are rare and have ages broadly synchronous with the Late Heavy Bombardment. Key Points: The Wolf crater complex is a volcanic caldera where silicic volcanism occurred between ∼3.6–3.7 Ga, followed by mafic volcanism till ∼2.02 GaStructural trends imposed by regional pre‐existing fracture systems facilitated both melt eruption and caldera collapseNear anhydrous melting of appropriate crustal protoliths caused by basaltic underplating generated the silicic melts [ABSTRACT FROM AUTHOR]

In the near future, international space agencies have planned to achieve significant milestones in investigating the utilization of Global Navigation Satellite Systems (GNSS) within and beyond the current space service volume up to their application to lunar missions. These initiatives aim to demonstrate the feasibility of GNSS navigation at lunar altitudes. Based on the outcomes of such demonstrations, dozens of lunar missions will likely be equipped with a GNSS receiver to support autonomous navigation in the lunar proximity. Relying on non-invasive, consolidated differential techniques, GNSS will enable baseline estimation, thus supporting a number of potential applications to lunar orbiters such as collaborative navigation, formation flight, orbital manoeuvers, remote sensing, augmentation systems and beyond. Unfortunately, the large dynamics and the geometry of such differential GNSS scenarios set them apart from current terrestrial and low-earth orbit use cases. These characteristics result in an increased sensitivity to measurements time misalignment among orbiters. Hence, this paper offers a review of baseline estimation methods and characterizes the divergences and limitations w.r.t. to terrestrial applications. The study showcases the estimation of the baseline length between a lunar CubeSat mission, VMMO, and the communication relay Lunar Pathfinder mission. Notably, real GNSS measurements generated by an Engineering Model of the NaviMoon receiver in the European Space Agency (ESA/ESTEC) Radio Navigation Laboratory are utilized. A radio-frequency constellation simulator is used to generate the GNSS signals in these hardware-in-the-loop tests. The performed analyses showed the invalidity of common terrestrial differential GNSS ranging techniques for space scenarios due to the introduction of significant biases. Improved ranging algorithms were proposed and their potential to cancel ranging errors common to both receivers involved was confirmed. [ABSTRACT FROM AUTHOR]

Launched in December 2022 onboard the Hakuto-R lunar lander, the Mohammed Bin Rashid Space Centre (MBRSC) Emirates Lunar Mission (ELM) Rashid-1 rover experienced an unsuccessful landing on the lunar surface on April 25th, 2023. The mission's prime landing site was Atlas crater, a 87 km diameter floor-fractured crater emplaced within the lunar highlands in the northeastern quadrant of the Moon. This paper describes the landing site selection procedure for the ELM Rashid-1 rover, from technical requirements that led to the selection of four broad areas of interest, to the placement of candidate landing ellipses based primarily on slope analysis and science interest. The rock abundance and presence of boulders were analyzed to verify the suitability of the target location for landing. Geological context as well as high resolution imagery and topography are presented for the four selected landing sites: Atlas crater (prime), Sinus Iridum, Oceanus Procellarum, and Lacus Somniorum (back-ups). Terrain characteristics and key science questions to be addressed at these locations are discussed, emphasizing the high scientific value of these locations for future lunar missions. [ABSTRACT FROM AUTHOR]

Estimates of doses inside the spacecraft were carried out for flights to the Moon using low-thrust engines. The characteristics of the trajectory, which is significantly different from the Hohmann trajectory, are taken into account. Such a trajectory causes a long stay inside the radiation belts, which can cause disruptions in the operation of onboard equipment. It turned out that, during long-term transportation of food products, they may be damaged under the influence of radiation. This is extremely important in the case of the creation of habitable stations on the Moon surface or near-Moon orbit. The presented results can be used in the preparation of future space experiments. [ABSTRACT FROM AUTHOR]

The paper presents new detailed radar maps and polarimetric data covering the southern polar region of the near side of the Moon measuring 400 × 800 km with a spatial resolution of about 75 m. The data were obtained using the 64-meter antenna (TNA-1500) of the Satellite Communications Center Bear Lakes of the Special Design Bureau of the Moscow Power Engineering Institute and the 13.2-meter radio telescope (RT-13) of the Svetloe Observatory of the Institute of Applied Astronomy, Russian Academy of Sciences, at a wavelength of 4.2 cm. At this wavelength, radar signals penetrate the lunar regolith to depths of up to 1 m and are sensitive to surface and suspended rocks larger than 1 cm. The maps show 39% of the area of permanently shadowed regions not observable by optical Earth-based instruments, which may hide water ice deposits. Analysis of radar maps did not reveal any relationship between the polarization properties of the surface in these regions and the presence of solar illumination. The data obtained as a result of this work can be used to study the surface and subsurface regolith features of the lunar south polar region, including searching for ice deposits in permanently shadowed regions, as well as for planning future lunar missions. [ABSTRACT FROM AUTHOR]

Legged robots offer advantages such as rapid mobility, adept obstacle-surmounting capabilities, and long mission life in lunar exploration missions. The low-gravity environment on the Moon enhances these benefits, particularly in enabling efficient jumps. However, challenges arise from the complexity of the jumping motion and the difficulty in maintaining stability. This paper introduces an innovative algorithm that integrates deep reinforcement learning with a main point trajectory generator, thus providing a reference for training with minimal reliance on human intuition and prior knowledge. Additionally, fine-grained policy optimization is achieved through a multistage reward structure based on the decomposition of the jumping process. Further, the concept of multitask experience-sharing is proposed to facilitate efficient learning across tasks involving plain terrain jumping and overcoming large obstacles. Simulation results demonstrate the effectiveness of the proposed algorithm in achieving precise and stable jumps, reaching heights approximately five times the robot's height and distances over five times its body length under lunar gravity. Moreover, the robot exhibits agile strategies, successfully overcoming platforms with a height of 2.5 times its body. [ABSTRACT FROM AUTHOR]

Lunar exploration and infrastructure development near the Moon's south pole, and at other future lunar settlements, demand a detailed understanding of the geotechnical properties, structure, composition, and stratigraphy of the near-surface lunar regolith. Long term exploration and development activities will require the use of regolith as a construction material for multiple structures, and as unrefined material for resource extraction during in situ resource utilization (ISRU) activities. Upcoming robotic and human exploration will be concentrated near the lunar south pole, which has a dominantly feldspathic composition typical of the lunar highlands. Past missions to lunar highlands terrain (Apollo 16, Luna 20) provide valuable "ground truth" data regarding the geomechanical properties of highlands regolith that serve as a guide for future exploration at the lunar south pole. Lunar highlands simulant LHS-1 has well-characterized geotechnical properties and is an appropriate analogue for highlands lunar regolith in terrestrial engineering studies. Cone penetrometer testing (CPT) measurements of LHS-1 reveal a strong exponential correlation between the G slope parameter and bulk density, which allows information to be obtained regarding the density profile of simulated regolith columns directly from CPT stress versus penetration curves. We show that LHS-1 can be used to replicate the near-surface regolith stratigraphy at the Apollo 16 highland landing region in Earth-based laboratories. The ultimate CPT penetration resistance measured in the laboratory under terrestrial gravity is not directly comparable to that measured under lunar gravity, and here we derive an average reduction factor of Rf = 0.29 to scale penetration resistance values to those measured in situ on the lunar surface. Geotechnical measurements of other lunar simulants combined with experiments similar to those described herein, tailored to the terrain type of interest, will provide crucial information to guide future regolith excavation, construction, and ISRU activities on the lunar surface. • LHS-1 lunar simulant is an appropriate geotechnical analogue for highlands regolith. • A strong correlation exists between CPT penetration resistance and regolith density. • Apollo 16 highlands regolith stratigraphy can be replicated on Earth using LHS-1. • Earth-based CPT values should be reduced by × 0.29 to adjust for lunar conditions. [ABSTRACT FROM AUTHOR]

Throughout the history of human spaceflight, spacefarers have experienced and reported the occurrence ofmedical conditions, including various illnesses and injuries. Therefore, future spaceflight missions to the Moon and Mars will require the capabilities necessary for maintaining the health of these new space travelers. Mass, power, and volume available in the space vehicles used for these missions will be severely constrained. The ability to resupply or evacuate to Earth will be limited or non-existent, and ground-based support will no longer be immediate due to communication latencies and blackouts. These vehicle and mission constraints will necessitate healthcare be provided from an efficiently planned medical system. To provide the necessary care, thesemedical systemswill need to include at aminimum, several different types of medical devices, consumable resources, centralized data management, procedural guidance, and decision support technologies. Medical devices needed for diagnosing and treating medical conditions that are expected to occur during future spaceflight missions may include real-time health monitoring, medical imaging capabilities, as well as blood and urine analysis. Novel methods for interacting with onboard patient medical records will be necessary, as will resource tracking. Terrestrial medicine sharesmany of these same needs, therefore a multitude of these required medical capabilities can likely be satisfied by currently available, Commercial-Off-The-Shelf (COTS) devices and methodologies; however, in some cases the unique space environment and increased mission durations will drive the need for modifications or customization of standard technologies and treatment procedures. This article will provide a review of medical devices and technologies that have been considered for inclusion within future spaceflight medical systems. It will also include a discussion about the modifications and customized development that have been performed, as well as descriptions of the technology demonstrations that have been conducted in analog and spaceflight environments. [ABSTRACT FROM AUTHOR]

Lunar seismic data are essential for understanding the Moon's internal structure and geological history. After five decades, the Apollo data set remains the only available one and continues to offer significant value for current and future lunar seismic data analyses. Recent advances in artificial intelligence for seismology have identified seismic signals that were previously unrecognized. In our study, we utilized deep learning for unsupervised clustering of lunar seismograms, leading to the discovery of a new type of long‐period lunar seismic signal that existed every lunar night from 1969 to 1976. We then conducted a thorough analysis covering the timing, frequency, polarization, and temporal distribution characteristics of this signal to study its properties, occurrence, and probable origins. This signal has a physical cause instead of artificial, such as voltage changes, according to its amplitudes during peaked and flat modes, as well as the digital converter status. Based on its relation to the lunar temperature and documents on Apollo instruments, we conclude that this signal is likely induced by the cyclic heater, with several unresolved questions that might challenge our hypothesis. Excluding interference from this newly identified signal is crucial when analyzing lunar seismic data, particularly in detecting lunar free oscillations. Our research introduced a new method for discovering new types of planetary seismic signals and helped advance our understanding of Apollo seismic data. Furthermore, the discovery of this signal holds valuable implications for the design of future planetary seismometers to avoid encountering similar issues. Plain Language Summary: For over 50 years, our only available lunar seismic data have come from the Apollo missions. These old but valuable data are still valid today, especially with artificial intelligence technology. We applied unsupervised deep learning techniques to study these lunar seismic data. Our study led to an exciting discovery: a new kind of signal in the lunar seismic data that happened every night on the Moon from 1969 to 1976. We examined this signal's timing, frequency, and other features to understand its nature and possible causes. Our studies show that this signal might not be a natural physical phenomenon but related to a cyclic heater on the lunar instrument. This discovery is significant as it helps us to avoid misinterpreting this new signal as other valuable signals, such as free oscillations, which can be used to investigate the Moon's internal structure. Our work sheds new light on the old Apollo lunar seismic data and can advise on the design of future lunar missions to avoid similar issues. Key Points: A new signal is discovered from Apollo seismograms by unsupervised learning, with a period of ∼500 s nightly from 1969 to 1976The signal matches peak/flat mode response shifts and relates to lunar temperature, likely caused by the cyclic operation of the heaterOur study presents a powerful method for discovering new seismic signals, providing insights into the design of future lunar seismometers [ABSTRACT FROM AUTHOR]

Crewed missions to the Moon may resume as early as 2026 with NASA's Artemis III mission, and lunar dust exposure/inhalation is a potentially serious health hazard that requires detailed study. Current dust exposure limits are based on Apollo‐era samples that spent decades in long‐term storage on Earth; their diminished reactivity may lead to underestimation of potential harm that could be caused by lunar dust exposure. In particular, lunar dust contains nanophase metallic iron grains, produced by “space weathering”; the reactivity of this unique component of lunar dust is not well understood. Herein, we employ a chemical reduction technique that exposes lunar simulants to heat and hydrogen gas to produce metallic iron particles on grain surfaces. We assess the capacity of these reduced lunar simulants to generate hydroxyl radical (OH*) when immersed in deionized (DI) water, simulated lung fluid (SLF), and artificial lysosomal fluid (ALF). Lunar simulant reduction produces surface‐adhered metallic iron “blebs” that resemble nanophase metallic iron particles found in lunar dust grains. Reduced samples generate ~5–100× greater concentrations of the oxidative OH* in DI water versus non‐reduced simulants, which we attribute to metallic iron. SLF and ALF appear to reduce measured OH*. The increase in observed OH* generation for reduced simulants implies high oxidative damage upon exposure to lunar dust. Low levels of OH* measured in SLF and ALF imply potential damage to proteins or quenching of OH* generation, respectively. Reduction of lunar dust simulants provides a quick cost‐effective approach to study dusty materials analogous to authentic lunar dust. [ABSTRACT FROM AUTHOR]

Chang'e-6 (CE-6) is the first sample-return mission from the lunar farside and will be launched in May of 2024. The landing area is in the south of the Apollo basin inside the South Pole Aitken basin. Statistics and analyses of impact craters in the landing area are essential to support safe landing and geologic studies. In particular, the crater size–frequency distribution information of the landing area is critical to understanding the provenance of the CE-6 lunar samples to be returned and can be used to verify and refine the lunar chronology model by combining with the radioisotope ages of the relevant samples. In this research, a digital orthophoto map (DOM) mosaic with resolution of 3 m/pixel of the CE-6 landing area was generated from the 743 Narrow Angle Camera of the Lunar Reconnaissance Orbiter Camera. Based on the DOM, craters were extracted by an automated method and checked manually. A total of 770,731 craters were extracted in the whole area of 246 km × 135 km, 511,484 craters of which were within the mare area. Systematic analyses of the crater distribution, completeness, spatial density, and depth-to-diameter ratio were conducted. Geologic model age estimation was carried out in the mare area that was divided into three geologic units according to the TiO2 abundance. The result showed that the east part of the mare had the oldest model age of μ 3.27 − 0.045 + 0.036 Ga, and the middle part of the mare had the youngest model age of μ 2.49 − 0.073 + 0.072 Ga. The crater catalogue and the surface model age analysis results were used to support topographic and geologic analyses of the pre-selected landing area of the CE-6 mission before the launch and will contribute to further scientific researches after the lunar samples are returned to Earth. [ABSTRACT FROM AUTHOR]

Within the emerging age of lunar exploration, optimizing transfer trajectories is a fundamental measure toward achieving more economical and efficient lunar missions. This study addresses the possibility of reducing the fuel cost of two-impulse Earth–Moon transfers in a four-body model with the Earth, the Moon, and the Sun as primaries. Lawden's primer vector theory is applied within this framework to derive a set of necessary conditions for a fuel-optimal trajectory. These conditions are used to identify which trajectories from an existing database could benefit from the insertion of an additional intermediate impulse. More than 10,000 three-impulse transfers are computed with a direct numerical optimization method. These solutions contribute to enriching the database of impulsive trajectories, useful to perform trade-off analyses. While the majority of trajectories exhibit only marginal improvements, a significant breakthrough emerges for transfers featuring an initial gravity assist at the Moon. Implementing a corrective maneuver after the lunar encounter yields substantial reductions in fuel costs. [ABSTRACT FROM AUTHOR]

In order to assist the ever growing number of missions planned to visit the Moon, an international effort is being made to design and commission a communication and navigation lunar constellation of satellites. To this purpose, the goal of this study is to provide first a strategy to help the design of a small-sized lunar constellation, entailing different objectives and users to assist. Then, various optimised constellations are tested including the orbital users' filtering architectures, extracting insights on the state estimation achievable and its capability to support critical GNC tasks. Given the early stage design phase in which this study is carried out, the constellation design does not entail strong and clearly defined requirements yet. For such reason, a multi-objective optimisation (MOO) has been employed, which proved to be extremely beneficial, ensuring a correct amount of versatility to provide a large set of Pareto-optimal solutions. Different objectives associated to both various services and users have been put in place, exploring a search space based on classical Keplerian elements of the constellation servicers. To compare the resulting constellations and validate correctly the performance from a navigation perspective the users navigation scheme has been considered to be based on a GNSS/INS tightly coupled formulation. The GNSS receiver measurements are fused with accelerometer outputs through a navigation filter, providing thus a strategy where the absence of GNSS observables is partially covered by an inertial propagation of the on-board state. Attention is here focused on polar orbiters operational in Low Lunar Orbit (LLO) environment and the obtained results showed navigation capabilities good enough to enable correct execution of missions in the low lunar orbital region. [ABSTRACT FROM AUTHOR]

The Artemis exploration zone is a geologically complex region likely to host some of the oldest and as‐yet‐unstudied materials on the Moon. We review six potential Artemis landing sites (001, 004, 007, 011, 102, and 105) within candidate Artemis III landing regions "Connecting Ridge," "Peak Near Shackleton," "Leibnitz Beta Plateau," "de Gerlache Rim," and "de Gerlache Rim 2." Kaguya Spectral Profiler mineral data were used to determine the average lithological composition at each landing site. Potentially accessible geologic materials, their ages and significance, and appropriate application of radiometric chronometers are discussed in reference to return samples from each potential landing site. Chronological analyses of return samples from the Artemis exploration zone will enable the anchoring of the lunar impact flux curve, determine the absolute timing of pivotal events in lunar geologic history, and reveal the geological diversity of the differentiated lunar body. Plain Language Summary: Artemis astronauts will bring new samples from the Moon back to Earth. We discuss the geology of some landing sites that astronauts might visit, what types of rocks they may encounter, and how to examine them using geochronology. The application of geochronology to Moon rocks is essential to determine the absolute timing of major events in lunar and early Solar System history. Key Points: The Artemis lunar missions will explore a feldspathic impact terrain and return samples from unexplored terrainLikely lithologies, ages, and chronometers are discussed for six potential landing sitesArtemis return samples from the Moon will be unique from Apollo samples and have the possibility of determining absolute ages of significant events in lunar history [ABSTRACT FROM AUTHOR]

Lunar mare basalt is recognized as an important in situ resource on the lunar surface. However, the significant compositional variability of lunar mare basalts introduces uncertainties concerning the potential for their use in fabricating fibers and composite materials. This study investigates the impact of different components on the fiber-forming capabilities of mare basalts by simulating the compositions of basalts collected from several well-known lunar missions and then preparing simulated lunar mare basalt fibers. Raman spectroscopy is primarily employed for analysis and characterization, using "peak area normalization" to explore the impact of compositional fluctuations in the simulated lunar mare basalts on the glass network structure. The findings indicate that an increase in the Fe content raises the likelihood of basalt fibers crystallizing. Additionally, Fe3+ is shown to substitute for Si and Al in constructing bridging oxygen bonds in the network structure, albeit reducing the overall polymerization of the network. Meanwhile, Fe2+ acts as a network modifier to enhance the mechanical properties of the fibers. [ABSTRACT FROM AUTHOR]

Summary: The Moon is the closest celestial body to the Earth. The examination and discovery of this planet have always played an important role in the history of humanity. Since the beginning of the space age, the Moon has been the target of many missions from the 1950s to the present day. Radio communication plays a fundamental role in space vehicle projects because this is the most obvious way to communicate with the ground station and transmit control commands and scientific data. From the early missions to the present day, Earth–Moon communication had many stages of development. In our article, we review this progress and then present the state‐of‐the‐art ideas related to the present missions through the missions currently underway and those planned for the near future. Our primary objective is to describe the radio communication relay services planned for orbit around the Moon. Furthermore, we present the European Space Agency (ESA)‐supported lunar missions, highlighting the Lunar Geology Orbiter (LUGO) mission. Finally, as a future perspective, we present the possibilities of optical communication in the Earth–Moon path, which can result a significant increase in capacity. [ABSTRACT FROM AUTHOR]

Since the landing on the lunar surface, the lunar regolith has begun to interact in different ways with landed elements, such as the wheels of a rover, astronaut suits, drills, and plants for extracting oxygen or manufacturing objects. Therefore, a strong effort has been required on Earth to fully characterise these kinds of interactions and regolith utilisation methods. This operation can only be performed by using regolith simulants, soils that are reproduced with the Earth's rocks and minerals to match the real features. This article presents the main guidelines and tests for obtaining the properties of a generic simulant in terms of composition, physical and mechanical properties, solid–fluid interaction, and thermal properties. These parameters are needed for the designing and testing of payloads under development for planned lunar surface missions. The same tests can be performed on lunar, martian, or asteroid simulants/soils, both in laboratory and in situ. A case study is presented on the lunar simulant NU-LHT-2M, representative of the lunar highlands. The tests are performed in the context of an in situ resource utilisation (ISRU) process that aims to extract oxygen from the lunar regolith using a low-temperature carbothermal reduction process, highlighting the main regolith-related criticalities for an in situ demonstrator plant. [ABSTRACT FROM AUTHOR]

This paper introduced automated detection and analysis of lunar craters are crucial for advancing lunar research and facilitating mission planning. This study introduces a comprehensive multi-scale approach for crater detection on the lunar surface using LROC (Lunar Reconnaissance Orbiter Camera) Dataset, enabling the identification of craters across varying scales and enhancing overall detection accuracy and efficiency. The process involves preprocessing lunar imagery to enhance features and delineate potential crater regions, utilizing edge detection algorithms to extract crater boundaries. Clustering techniques are then applied to group similar edge points and isolate potential crater candidates. A thresholding mechanism based on statistical edge intensity analysis refines the detection process. To address multiple detections of the same crater at slightly different diameters, radius criteria are implemented, yielding high diameter accuracy of 84% for mare Imbrium (test site 1) and 80% for mare Nubium (test site 2). Subsequently, a depth-diameter analysis validates crater-like characteristics by combining depth measurements with crater diameter estimation, showcasing the authenticity of potential craters. we compare our diameter and depth with different reference papers and we get high accuracy of R2 =0.99 then other methods. The results highlight the potential of this multi-scale approach for automated lunar crater detection, providing deeper insights into the Moon's surface morphology and history for future lunar exploration missions. [ABSTRACT FROM AUTHOR]

Introduction: Physical regolith simulants are valuable tools for developing In-Situ Resource Utilisation hardware. However, using virtual models of regolith instead can reduce costs, limit exposure to hazardous materials, and offer a practical method of testing the effects of reduced gravity. Methods: We verify a virtual model of regolith as macroparticles against physical tests. Using space partitioning techniques to identify neighbouring particles, we present a scalable model of regolith, in which the computation time increases roughly proportionally with the number of particles. We evaluated the performance of this virtual simulant vs. a physical simulant (Exolith LMS-1) by comparing the flow rate through funnels of various diameters, and the resultant angle of repose of material on both large (500 g) and small (16 g) scale tests. Results: For large scale tests, the flow rates were within the predicted range for macroparticles with radii 3-7 mm, with the greatest accuracy achieved for radii 4-5 mm. However, the macroparticles blocked the simulated funnels more easily than in the physical trials, due to their high cohesion. The angle of repose was not accurately represented by this model for either of the tests. Discussion: The high efficiency of this model makes it best suited for applications which require large scale approximations of regolith with real-time execution, such as virtual training for robot operators or providing visual and haptic feedback in model-mediated teleoperation systems. The results of this model in reduced gravity could be further verified against data from upcoming lunar missions in future work. [ABSTRACT FROM AUTHOR]

• Photometric correction of IIRS images obtained from the Chandrayaan-2 mission. • IIRS data were found to be comparatively darker than Chandrayaan-1 M3. • Derived IIRS reflectances show minimal variation compared to M3 values. • Derived phase function fits for 950, 1500, and 1700 nm channels have high R2. • Absence of major artifacts (including cross-tracks) on IIRS data. India's second mission to the Moon, Chandrayaan-2, carried one of the most advanced imaging spectrometers ever sent to image a planetary surface – the IIRS (Imaging Infra-Red Spectrometer) – a 250 band spectrometer developed at the Space Applications Centre (SAC), ISRO, India. In this study, IIRS data between 800 and 2000 nm have been used to derive photometrically corrected reflectance from calibrated radiance data supplied by ISRO's online archive (Pradan) of Chandrayaan-2 data. Additionally, the photometric properties of three IIRS bands (950, 1500, and 1700 nm) have been studied in detail. Since the images obtained by IIRS are at different viewing geometry orientations, the purpose of performing a photometric correction on IIRS images is to re-project each pixel to a standard viewing geometry of incidence angle, i = 30°, emission angle, e = 0° and, phase angle, α = 30°. In order to correct the lunar limb darkening effect, a combination of the Lommel-Seeliger function and McEwen's model was used. In addition, topographic data from the merged Digital Elevation Model of Lunar Reconnaissance Orbiter – Lunar Orbiter Laser Altimeter (LRO-LOLA) and SELENE Terrain Camera (TC) were utilized to remove effects from local topography. A photometric function was then applied on four images captured by IIRS which were included in the first public release of data in August 2021. Radiance and reflectance (obtained after implementing photometric correction on IIRS images) values were compared with L1 and L2 M3 (Moon Mineralogy Mapper) data from Chandrayaan-1. It was found that although IIRS images are much darker than M3, corrected IIRS reflectance images had a much smaller variation in terms of reflectance values with M3. Moreover, the associated spectral reddening and reflectance values are within range when compared with data from other lunar missions. In addition, the reflectance spectra derived from the corrected IIRS images have been plotted for each image. However, the spectra exhibit significantly deeper absorptions than their corresponding M3 data for the same pixel. Phase functions derived from three bands have a good correlation with the reflectance values and phase angles. Consequently, this function can be applied to all IIRS images as and when more data are released to the public. [ABSTRACT FROM AUTHOR]

Water resources are essential to human exploration in deep space or the establishment of long-term lunar habitation. Ice discovered on the Moon may be useful in future missions to the lunar surface, necessitating the consideration of in situ resource utilization if it is present in sufficient amounts. Extraction of ice can cause the regolith to settle, which can lead to unintended structural damage. Therefore, any settlement resulting from ice extraction should be understood from a geotechnical perspective. This work reports on experimental investigation of the potential settlement caused by the extraction of ice from lunar regolith simulant containing different textures of ice. The KLS-1 simulant was prepared with different water contents and ice textures. Significant settlement occurred in simulant–ice mixtures with initial water contents of 5–10%. [ABSTRACT FROM AUTHOR]

Modern planetary rovers are based on aluminum chassis, but thanks to carbon fiber composites, the weight of such mobility platforms can be dramatically lowered. This paper describes the design of a 6-wheeled rover with a rocker-bogie suspension, adopting carbon fiber laminates and short-fiber-reinforced polymers. This last feature is an innovative approach that fits well with the use of additive manufacturing, allowing for both highly optimized parts and rapid fabrication of spares in future manned missions on the Lunar surface. The structural design was validated against a set of boundary conditions (static analyses) and requirements of launch and space environments (dynamic analyses) as prescribed by European Cooperation for Space Standardization standards. The composite rover was designed to lighten the structure itself and increase the payload-to-total-mass ratio: the composite solution offers a ratio three times higher than the typical rover (ratio from 0.12 to 0.38). [ABSTRACT FROM AUTHOR]

This review article provides an overview of various aspects of lunar exploration, including missions to the Moon, collection and analysis of lunar sample data in laboratories, and the processing and analysis of remote sensing data, particularly using radar techniques. Both remote sensing and in-situ methods are critical for advancing our understanding of the lunar surface and its properties. This review article focuses on the identification and quantification of water–ice deposits located in areas such as Permanently shadowed areas (PSRs) and the lunar poles (section " Lunar Poles and PSRs: A Special Environment "). These volatile resources have the potential to serve as valuable sources of fuel for future missions, making it crucial for the lunar community to determine their abundance and distribution. After thoroughly examining lunar samples using high-precision laboratory techniques, many preconceptions were dispelled which is highlighted in the section " Laboratory Investigation of Lunar samples ". But as in-situ observations are difficult to acquire, especially terrestrial bodies samples, remote sensing techniques allow the global understanding of the surface. The article specifically highlights the importance of understanding the electrical characteristics of the lunar surface and how radar inversion can provide valuable information in this regard. The " Conclusion " section of this review article serves as a key takeaway for readers, underscoring the critical role that both in-situ and remote sensing techniques play in advancing our understanding of the Moon. [ABSTRACT FROM AUTHOR]

As the cornerstone mission of the fourth phase of the Chinese Lunar Exploration Program, Chang'E-7 (CE-7) was officially approved, and implementation started in 2022, including a main probe and a communication relay satellite. The main probe, consisting of an orbiter, a lander, a rover and a mini-flying probe, is scheduled to be launched in 2026. The lander will land on Shackleton crater's illuminated rim near the lunar south pole, along with the rover and mini-flying probe. The relay satellite (named Queqiao-2) will be launched in February 2024 as an independent mission to support relay communication during scientific exploration undertaken by Chang'E-4, the upcoming Chang'E-6 in 2024 and subsequent lunar missions. The CE-7 mission is mainly aimed at scientific and resource exploration of the lunar south pole. We present CE-7's scientific objectives, the scientific payloads configuration and the main functions for each scientific payload with its key technical specifications. [ABSTRACT FROM AUTHOR]

Over the past few years, the international space industry has focused extensively on advancing technologies to enable prolonged human space exploration missions. The primary limiting factor for these endeavors is the spacecraft's capacity to transport and store essential supplies from Earth to support human life and mission equipment throughout the mission's duration. In-situ resource utilization (ISRU) is the preferred solution for this challenge. Previous lunar missions have identified the presence of oxygen within the lunar regolith, which is an important resource for human space exploration missions. Oxygen is present in many different minerals within the lunar regolith out of which, ilmenite provides the highest yield of oxygen per unit mass using hydrogen reduction. However, the distribution of ilmenite is neither high nor uniform throughout the lunar surface and therefore, needs beneficiation, which is an important intermediate step for ilmenite-based oxygen production. A regolith beneficiation testbed was developed at DLR Bremen which is a TRL 4 level representation of the technology. The testbed has multiple process parameters that can be adjusted to produce the desired feedstock. This work focuses on the optimization of this testbed to produce a feedstock with higher ilmenite content than the input regolith. The testbed comprises three beneficiation techniques, viz. gravitational, magnetic and electrostatic beneficiation that work sequentially to produce the desired feedstock. The optimized parameter configuration achieved up to three-fold increase in the ilmenite grade relative to the input with about 32 wt% of the total ilmenite being recovered in the enriched output. These experiments have highlighted other underlying factors that influenced the experimental research such as the design of testbed components, system residuals and limited availability for Off-the-shelf components. The observations made from these experiments have also provided insights into the further development of the technology. The work has thus produced evidence for the effectiveness of the beneficiation testbed in producing an enriched feedstock while outlining avenues for future improvements. [ABSTRACT FROM AUTHOR]

Chinese lunar landing mission Chang'E-4 reached the far side of the Moon in January 2019 and has been providing unprecedented Lunar Penetrating Radar data able to explore the lunar subsurface down to more than 40 m (with its more resolutive high frequency band). Data are periodically released to the scientific community in raw PDS4 format. Here we provide different versions of the radar dataset after editing (i.e. pre-processing), partial, and full processing in order to provide a complete ready-to-use dataset to end-users (data collected since 4th January 2019 until 27th March 2023) which can be directly exploited for analysis, interpretation, inversion, as well as integration with imagery or other information. In particular, we implemented an efficient and objective way to remove duplicated traces representing more than 90% of original data, as well as a processing flow able to retain all the original data information, while avoiding redundancies. The provided datasets can be implemented with future data releases and straightforwardly exploited for any future analysis. [ABSTRACT FROM AUTHOR]

We present new radar images and polarimetric data for the candidate landing sites of the Russian Luna-25 spacecraft near the Manzinus and Boguslawsky craters in the south polar region of the Moon. The images were obtained with the 64-m TNA-1500 antenna at the Bear Lakes Satellite Communications Center of the Special Design Bureau of the Moscow Power Engineering Institute and the 13.2-m RT-13 radio telescope at the Svetloe Observatory of the Institute of Applied Astronomy of the Russian Academy of Sciences in a bistatic configuration at a wavelength of 4.2 cm. At this wavelength the radar signals can penetrate into the lunar regolith to a depth up to 1 m and are sensitive to surface and suspended rocks with a diameter of about 1 cm or more. A spatial resolution m per pixel was achieved through the focused processing algorithm that avoids the radar image smearing at a long integration time. The receiving-system noise temperature measurements during the entire observation session provided a reliable estimate of the circular polarization ratio (CPR) of the echo signal. Analysis of the radar images obtained revealed regions with high radar backscatter and CPR. The number and distribution of rocks and irregularities with sizes comparable to the radar wavelength on the surface and in the near-surface layer of regolith were estimated. As a result of the radar data analysis, we conclude that the surface and the near-surface regolith layer of the main site are smoother than those of the reserved site, which makes it preferable for landing. Thus, the resulting new radar images and CPR maps can be used in planning future lunar missions. [ABSTRACT FROM AUTHOR]

India's achievement in launching the Chandrayaan 3 lunar mission marks a turning point in its space exploration endeavours, with far-reaching implications that extend beyond technological success. This article discusses the strategic importance of Chandrayaan 3's successful landing on the lunar surface, emphasizing its implications for India's technological advancement, defense capabilities, education sector and economic growth. Furthermore, it delves into the challenges faced by the Indian space program, including limited budget allocations, technological dependencies, and market access. Drawing insights from global space initiatives, the article proposes strategic recommendations for realizing India's full potential in the space domain, such as substantial investment, expertise in human spaceflight and private sector participation. Through a comprehensive analysis of Chandrayaan 3's multidimensional impact, this article contributes to the scholarly discourse on space exploration and underscores India's growing prominence in the global space community. [ABSTRACT FROM AUTHOR]

This paper investigates the performance of the forthcoming lunar navigation satellite systems for estimating not only the position of an onboard receiver in a lunar inertial reference frame but also, and with a consistent accuracy, the relative position between two or more spacecraft in proximity. This could be the case of two spacecraft performing a rendezvous, of a lander released by an orbiter, or the case of the permanent relative navigation service for a formation of satellites around the Moon. The considered observables are the pseudorange and pseudorange-rate measurements provided by the upcoming lunar communication and navigation system (LCNS), expected to support lunar missions. A single-stage Kalman filter is implemented, and its performance is demonstrated through error statistics, which are then compared to what can be achieved with sequential filtering. [ABSTRACT FROM AUTHOR]

Over the previous two decades, a notable array of space exploration missions have been initiated with the primary aim of facilitating the return of both humans and robots from Earth to the moon. The significance of these endeavors cannot be emphasized enough as numerous entities, both public and private, from across the globe have invested substantial resources into this pursuit. Researchers have committed their efforts to addressing the challenges linked to lunar communication. Even with all of these efforts, only a few of the many suggested designs for communication and antennas on the moon have been evaluated and compared. These designs have also not been shared with the scientific community. To bridge this gap in the existing body of knowledge, this paper conducts a thorough review of lunar surface communication and the diverse antenna designs employed in lunar communication systems. This paper provides a summary of the findings presented in lunar surface communication research while also outlining the assorted challenges that impact lunar communication. Apart from various antenna designs reported in this field, based on their intended usage, two additional classifications are introduced: (a) mission-based antennas—utilized in actual lunar missions—and (b) research-based antennas—employed solely for research purposes. Given the critical need to comprehend and predict lunar conditions and antenna behaviors within those conditions, this review holds immense significance. Its relevance is particularly pronounced in light of the numerous upcoming lunar missions that have been announced. [ABSTRACT FROM AUTHOR]

Biologics, such as pharmaceutical peptides, have notoriously short shelf lives, insufficient for long-duration space flight missions to the Moon or Mars. To enable the sustainable presence of humans on the Moon or Mars, we must develop methods for on-site production of pharmaceutical peptides in space, a concept we call the Astropharmacy. Here, we present a proof-of-concept for the first step needed: a low-mass system for pharmaceutical production designed to be stable in space. To demonstrate feasibility, we engineered strains of the space-hardy spore-forming bacterium, Bacillus subtilis, to secrete two pharmaceutical peptides important for astronaut health: teriparatide (an anabolic agent for combating osteoporosis) and filgrastim (an effective countermeasure for radiation-induced neutropenia). We found that the secretion peptides from the walM and yoqH genes of B. subtilis worked well for secreting teriparatide and filgrastim, respectively. In consideration of the Translational Research Institute for Space Health (TRISH) challenge to produce a dose equivalent in 24 h, dried spores of our engineered strains were used to produce 1 dose equivalent of teriparatide from a 2 mL culture and 1 dose equivalent of filgrastim from 52 mL of culture in 24 h. Further optimization of strain growth conditions, expression conditions, and promoter sequences should allow for higher production rates to be achieved. These strains provide the template for future optimization efforts and address the first step in the Astropharmacy, capable of on-site production, purification, and processing of biopharmaceutical compounds in platforms amenable for use in space. [ABSTRACT FROM AUTHOR]

The Celestial Object Rendering TOol (CORTO) offers a powerful solution for generating synthetic images of celestial bodies, catering to the needs of space mission design, algorithm development, and validation. Through rendering, noise modeling, hardware-in-the-loop testing, and post-processing functionalities, CORTO creates realistic scenarios. It offers a versatile and comprehensive solution for generating synthetic images of celestial bodies, aiding the development and validation of image processing and navigation algorithms for space missions. This work illustrates its functionalities in detail for the first time. The importance of a robust validation pipeline to test the tool's accuracy against real mission images using metrics like normalized cross-correlation and structural similarity is also illustrated. CORTO is a valuable asset for advancing space exploration and navigation algorithm development and has already proven effective in various projects, including CubeSat design, lunar missions, and deep learning applications. While the tool currently covers a range of celestial body simulations, mainly focused on minor bodies and the Moon, future enhancements could broaden its capabilities to encompass additional planetary phenomena and environments. [ABSTRACT FROM AUTHOR]

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. • The heat generated by the deposition of water vapor enhanced heat transfer. • The rose in water vapor pressure augments the thermal conductivity of the gas. • The structure of the mining equipment significantly affects vapor flow in icy soil. • Water ice could advance future deep drilling missions in the Moon's PSRs. [ABSTRACT FROM AUTHOR]