Lunar Regolith Research Articles

Developing an alternative medium for in-space biomanufacturing

In-space biomanufacturing provides a sustainable solution to facilitate long-term, self-sufficient human habitation in extraterrestrial environments. However, its dependence on Earth-supplied feedstocks renders in-space biomanufacturing economically nonviable. Here, we develop a process termed alternative feedstock-driven in-situ biomanufacturing (AF-ISM) to alleviate dependence on Earth-based resupply of feedstocks. Specifically, we investigate three alternative feedstocks (AF)—Martian and Lunar regolith, post-consumer polyethylene terephthalate, and fecal waste—to develop an alternative medium for lycopene production using Rhodococcus jostii PET strain S6 (RPET S6). Our results show that RPET S6 could directly utilize regolith simulant particles as mineral replacements, while the addition of anaerobically pretreated fecal waste synergistically supported its cell growth. Additionally, lycopene production using AF under microgravity conditions achieved levels comparable to those on Earth. Furthermore, an economic analysis shows significant lycopene production cost reductions using AF-ISM versus conventional methods. Overall, this work highlights the viability of AF-ISM for in-space biomanufacturing.

Lunar Power Sources: An Opportunity to Experiment

This paper presents a systematic analysis of power generation technologies for a lunar outpost supporting six astronauts. Based on a detailed power budget analysis requiring 65 kWe for life support, scientific equipment, and in situ resource utilization (ISRU), a comparative analysis of solar and nuclear power solutions is conducted. Nuclear fission is identified as the most promising technology based on key criteria, including mass efficiency, reliability, and power density. A parametric study is then conducted to optimize the nuclear reactor design, with particular focus on radiation shielding using lunar regolith and its impact on safety distances. The analysis demonstrates that proper shielding can reduce the required safety distance from over 2.5 km to approximately 90 m while maintaining radiation exposure within acceptable limits. Finally, leveraging insights from existing reactor designs, an optimized configuration is proposed that combines multiple small reactors to meet the unique challenges of lunar power generation while ensuring crew safety and operational redundancy.

Regolith-Rich PEEK Composite Bricks: Steps Towards Space-Ready Lunar Construction Materials

This study introduces a novel composite construction material composed of lunar regolith combined with PEEK in dry powder form. The work demonstrates significant advantages over alternative methods, primarily by reducing production power consumption and simplifying the manufacturing process. Building on previous research that explored binder optimization through process simplification and targeting predefined shapes, this work delves deeper into a comparative analysis of high-performance thermoplastics. Among the various options, PEEK demonstrates the most favorable properties. The study investigates key processing parameters and evaluates the effects of vacuum processing and temperature testing on mechanical properties. The research also evaluates the effects of vacuum processing and temperature testing to assess the material’s performance under lunar conditions. Comparative analysis is performed with standard performance of various reinforced and unreinforced concretes and with standard requirements for construction bricks as per ASTM standards. This shows that the composite, with an organic binder content as low as 5 wt%, has great potential. Notably, the improvements achieved through vacuum curing ensure compliance with lunar environmental conditions and alignment with most Earth-based engineering standards. Samples compacted at 7.50 MPa with 10 wt% binder, and tested at room temperature, achieve a compression strength of 16.3 MPa, exceeding that of industrial floor bricks and matching that of building bricks used on Earth. Bending strength (7.4 MPa) aligns with steel fiber-reinforced and high-strength concretes. Vacuum curing further enhances these properties, with an observed increase of +66% in bending strength and +33% in compression strength.

Ultrafast Joule Heating Processing of Lunar Soil Minerals for Water Electrolysis

Ultrafast Joule Heating Processing of Lunar Soil Minerals for Water Electrolysis

Detectability of the passage of the heliosphere through an interstellar cloud with cosmogenic nuclides in lunar soil

As the Sun traverses interstellar space it may encounter interstellar molecular clouds (IMCs) characterised by higher particle densities than in the ambient interstellar medium. These occurrences have, for example, been proposed to explain the increase of ^60Fe measured in sea sediments. Magnetohydrodynamic (MHD) simulations show that such IMC crossings effectively shrink the heliosphere, thereby reducing its ability to modulate the incident spectrum of galactic cosmic rays (GCRs). Therefore, the hallmark of such encounters in the past may be increased GCR intensities, which can be detected via analyses of cosmogenic nuclides in lunar regolith samples. The present study proposes a method for testing whether such IMC crossings have indeed occurred in the past, by analysing the rates at which the long-lived cosmogenic nuclide (lifetime 1.0 Myr) is formed in lunar soil samples. Cosmogenic nuclide production rates at varying depths in lunar soil are related to a corresponding GCR modulation potential, which in turn is related to a corresponding modulation boundary, and hence interstellar density, via a scaling relation based on published MHD simulation results. A lower limit for the detectability of past heliospheric crossings of IMCs is presented, governed by the amount of time spent in such a cloud: shorter passages may be undetectable, but longer passages would be clearly observable. However, we find no evidence of the Solar System encountering a cold, dense cloud. Lunar cosmogenic nuclides represent a powerful tool whereby the past modulation history of the heliosphere can be revealed over timescales of millions of years, which in turn can provide invaluable insights as to the past interstellar environment encountered by the Sun. However, techniques such as the one proposed here will benefit greatly from new, higher-precision analyses of existing lunar samples.

Enhancing economical lunar-based manufacturing by incorporating lunar regolith into polyether–ether–ketone (PEEK): material development, additive manufacturing, and characterization

Enhancing economical lunar-based manufacturing by incorporating lunar regolith into polyether–ether–ketone (PEEK): material development, additive manufacturing, and characterization

Chemical analysis of Chang'e-5 lunar soil using LA-ICP-MS in highly diluted fused glass discs

The bulk chemical compositions of extraterrestrial materials can provide critical information on the evolution and magmatism of planetary bodies.

Morphological Observation and Mineralogical Analysis of Basaltic Debris from a Chang'e 5 Drilled Sample

This paper analyzes the morphological characteristics and mineralogy of drilled basaltic clast sample CE5Z0806YJYX004, compares the variations in Chang'e-5 samples at different depths, and conducts a comparative analysis with surface-collected samples from Chang'e-5 and Apollo missions. Interestingly, Advanced electron microscopy identified bubbles and microcracks on the surface of some constituting mineral particles, and also displays crystalline particles with distinct rock textures and spherical droplets, revealing surface phenomena formed by space weathering. Based on Raman spectroscopy analysis, the main mineral phases were identified as 49.6 vol% pyroxene, 31.4 vol% plagioclase and 8.8 vol% olivine. Apatite, ilmenite and cristobalite are also found. The results indicate that the Chang’e-5 lunar soil exhibits similar mineral compositions at different depths. In short, a comparison was made between our drilling sample and the Chang'e 5 soil samples as well as samples from the Apollo mission series, demonstrating the physical similarities and some variations.

Oblique Impact Adjacent to Chang'E−5 Sampling Site: Fine‐Scale Analysis and Implication on the Provenance of Returned Samples

AbstractImpact ejecta is a major source of lunar regolith. Symmetric ejecta thickness models are widely used to estimate ejecta distribution. However, they cannot accurately describe the asymmetric distributions from oblique impacts. Here, the Xu Guangqi crater provides an example for the study of oblique impacts. High‐resolution data from this crater, acquired during the Chang'E−5 mission, has facilitated studies of a potential oblique impact, the development of a correction model for asymmetric ejecta distribution, and a detailed analysis of regolith provenance at the sampling site. The results show that the Chang'E−5 returned samples mainly originate from the Xu Guangqi crater formed by an oblique impact at 25°–45°, and its corrected ejecta thickness at the sampling site is about 80 cm, an increase of about 30% over the estimate from the original symmetric ejecta thickness model. Within the uppermost 5 cm, the Chang'E−5 returned regolith is modeled to consist mainly of Xu Guangqi ejecta (∼99%) and a small number of local materials (∼1%), but both are similar in composition composed of local mare basalts. Although small quantities (∼0.7%) of nonlocal mare components from Sharp B, Copernicus, Harpalus, and Aristarchus occur at the bottom of the drilled samples (80–90 cm), the samples are still dominated by Xu Guangqi ejecta (∼88%) and local materials (∼11%). Our study demonstrates the possible effect of an oblique impact to be considered when discussing the sample provenance for a lunar sample returning mission.

Nonplanar wave modulation and rogue wave formation in lunar dusty plasma

Abstract Motivated by the coming lunar missions, namely Luna-25 and Luna-27, scheduled for landing in the coming years, the investigation of the properties and characteristics of lunar dust, which, in contrast to terrestrial dust, adversely affects technology and creates significant risks to humans. As the Moon orbits Earth, plasma from its surroundings impacts its surface and dust grains above and below; thus, about one-third of the moon's orbit is occupied by the tail magnetosphere, which is thicker and more energetic than the tail regions' very thin plasma. Therefore, investigating the plasma properties in this region is of interest to avoid any unfavorable waves that may affect on the space vessels electronics. For this purpose, we use a three-component plasma fluid model study non-planar nonlinear electrostatic wave modulation on the lunar dark side. A non-planar, nonlinear Schrödinger equation (NLSE) is derived to examine the nonlinear wave envelope, which is produced from the dynamics of lunar negatively charged dust particles, positively charged ions, and Maxwellian electrons. Slow and fast dust-ion acoustic modes exist. The instability region allows the occurrence of nonlinear wave envelopes in the form of rogue waves. The latter are proposed as a physical, temporal, and spatial concentration of energy within a localized wave packet, which is sufficient to establish accumulation particles and influence the overall stability of the environment. The relative ion-to-electron temperature ratio enhances the fast mode's maximum growth rate. The growth rate of modulational instability for the spherical mode is lower than that for the cylindrical mode.

Bioinspired Active Dynamic Dust Remover for Multiscale Stardust Repelling of Unmanned Probe Surface.

Unmanned probes, mainly powered by solar panels, are effective tools for exploiting space resources to expand the human habitat. However, it remains a great challenge for the unmanned probes to actively repel multiscale dust particles in space. Inspired by the synergistic antifouling mechanism of fly wings and legs, a biomimetic dynamic antifouling surface (BDAS) was prepared based on a combination of self-assembly and template inversion. BDAS consists of flexible and controllable cilia with ultrahigh aspect ratio. Under the control of an external magnetic field, BDAS can perform three modes of dust removal tasks. The synergism of these three modes ensures that BDAS provides superior dust removal against multiscale dust particles in complex environments. Compared to conventional passive dust removal surfaces, the dust removal efficiency is increased by 941%. As proof of concept, BDAS was installed on a lunar probe and achieved effective removal of simulated lunar soil (up to 1158%).

The Luna Analog Facility testbeds (ESA, EAC): contemporary characterization work of highland (lunar) and mare (EAC-1) lunar regolith simulants

The Luna Analog Facility, a joint ESA-DLR endeavour, consists of three components and spans an area of 1,000 m2, providing testbeds of simulated lunar environments. The main sections within the facility are a large area filled with lunar mare regolith simulant resembling mare regions and a smaller, individual “Dust Chamber”. The latter replicates highland conditions and contains approximately 20 tons of material, specifically simulating the fine-particle lunar regolith portion up to 250 µm. The Dust Chamber serves as a platform for testing various technologies, such as mechanical tools, robotic operations, in-situ resource utilization activities, and astronaut attire, as well as different procedures including rover and astronaut tasks. This work represents the geotechnical, geochemical and mineralogical characterization of the Lumina Sustainable Materials Ltd. 2023 batch highland simulants, from which Lunar250 is intended for use in the Luna Dust Chamber. Additionally, this work provides new results for ESA’s mare simulant, EAC-1. We provide data on particle size distribution, particle shape, abrasivity, density, water content, major and trace element geochemistry and modal mineralogy. As the simulants in the Luna Facility will be constantly overseen, this work organized by the Vulcan Facility (ESA) intends to support the monitoring of the geotechnical property variations of the simulants over time. Ultimately, we analysed several properties with different tools to emphasize how different methods and instruments affect the variability and reliability of the results.

Tribological Investigation of Polymer Composite Dynamic Shaft Seals in Extraterrestrial Applications

Polymer seals are utilized in various engineering applications to prevent leakage and contamination. The study investigates the wear and friction behavior of PTFE-based dynamic rotary seals, targeting their usage in space applications. Pin-on-disc dry sliding wear tests were performed with 0.5 MPa contact pressure and 0.2 m/s sliding velocity combining different lip seal (PTFE, PTFE+GF+MoS2), packing (PTFE, PTFE+Aramid fiber+solid lubricant) and shaft materials (34CrNiMo6, PEEK) involving third-body lunar (LHS-1) and Martian regolith (MGS-1) simulants. To understand the different influences of extraterrestrial regolith simulants compared to commonly encountered abrasives on Earth, quartz sand was selected as a reference. Quartz soil resulted in lower wear rates but a similar coefficient of friction to other regoliths. In the case of lip seals, testing with LHS-1 on PEEK and testing with MGS-1 on steel resulted in the most severe wear. Post-mortem surface analysis revealed the effect of external abrasive particles on the wear process and the transfer layer formation. The surface analysis confirmed that both lunar and Martian regolith simulants resulted in significant embedded particles. Based on the wear performance results, the lip seals performed better, but installation with an external packing could further aid the tribosystem.

Regolith as raw material for the production of aggregates and concrete-like composites on the Moon

The presented research program is focused on harnessing lunar regolith as raw material for the production of aggregates and concrete-like composites on the Moon. The proposed complex technological solution covers technology of lunar aggregate production, lunar concrete-like composites, shape of a lunar habitat, a type of its structure and erection technique. Each element of the proposed solution is supported by tests or calculations. In authors’ opinion magnetic separation seems to be the most promising technology of lunar aggregate production, habitats should be in egg-shaped form and the structure should be 3D printed as a Voronoi mesh. The research program was conducted using scientifically proven lunar soil simulants which were thoroughly tested by the authors. Production of lunar aggregate and subsequently concrete-like composite based on it is inevitable. The authors’ proposed approach to the erection of lunar habitats is fully based on in-situ resource utilization philosophy increasing its feasibility. Necessary future research areas were pointed out.

Structure and formation mechanism of lunar regolith

Structure and formation mechanism of lunar regolith

The LimPa mission: a small mission proposal to characterize the enigmatic lunar dust exosphere

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.Graphical abstract

Lunar dust dermatologic considerations for NASA's artemis program and the gateway space station: a narrative review.

The Artemis program and lunar gateway present an opportunity to advance NASA's presence away from Earth's orbit and back to the Moon. Astronauts will be faced with many dermatological challenges unique to the lunar environment, such as the surface material on the Moon. We used PubMed and Google Scholar to perform a literature review with articles related to the effects of lunar dust on skin collated and analyzed to assess the dermatological implications of these missions. The effects of lunar dust on wound generation and healing were reviewed, while also analyzing passive and active measures used to minimize astronaut exposure to lunar dust. A myriad of methods involving advances in medicine and engineering (e.g. bioinspired texturing of materials, staged decontamination, emollients) will need to be employed to best protect astronauts from the effects of lunar surface materials and other insults to best protect the Artemis astronauts. These advances will help with future NASA missions to Mars and beyond as other terrestrial space bodies will likely present astronauts with similar dermatological insults from surface materials and regolith. Dermatologists can serve a role in helping researchers develop techniques to protect skin health and understand the pathophysiology involved with lunar dust exposure.

Enhancing Discrete Element Model Accuracy for Lunar Soil: Calibration and Validation of Mesoscopic Parameters

To enhance the precision of the discrete element model for lunar soil-tool simulation work, this paper introduces a novel discrete element model of lunar soil incorporating particle shape and the van der Waals forces between particles. The effect of mesoscopic parameters on peak stress and failure point are systematically calibrated in the model by triaxial compression stress-strain curves. The results show that six meso-parameters have significant impact on the mechanical response of the model, including effective modulus, rolling friction coefficient, normal-to-shear stiffness ratio, damping coefficient, maximum attractive force and attraction range. The model accurately simulates complex mechanical behavior in both loose, dense lunar soils and soil-tool interaction. This study lays a foundation for future lunar soil-anchor interaction simulation and the interpretation of lunar soil mechanical parameters.

Adhesion of Silicate Impact Melts on Impact Glasses of Chang'e‐5 Regolith

AbstractMicroscopic silicate melts are ubiquitous on surfaces of lunar regolith particles, and they record physicochemical processes of regolith reworking on the Moon. Similar microstructures are visible on surfaces of the Chang'e‐5 lunar impact glass particles, which are predominantly sourced from local mare deposits. Therefore, the microscopic silicate melts provide an invaluable opportunity to study the movements, provenances, and chemical alterations of substances involved in regolith reworking. However, the small lateral sizes and thicknesses of the surface silicate melts are a challenge for quantifying their internal structures and geochemical compositions, hampering interpretations of their origin. Here we report structural and geochemical characteristics for microscopic silicate pancakes, domes and foams on surfaces of Chang'e‐5 impact glass particles. Based on the contact and compositional differences between the surface microscopic silicate melts and their host glass, we reveal that these microstructures are consistent with being formed during impact bombardment in regolith via adhesion of impact melts to earlier‐existing glasses. Most of the microscopic silicate melts have minor compositional differences with the host glass. Our mixing calculations for compositions of impact melt formed from various proportions of local regolith minerals at the landing site reveal a dominant precursor from the local mare deposits. Few portions of the microscopic silicate melts have exotic compositions that are different from the local regolith materials, confirming that ejecta from the other geochemical terrains is minor at the landing site. Our results show that regolith formation and reworking at the Chang'e‐5 sampling site mainly involved local mare deposits.

Micro-Raman and FTIR spectroscopic characterization of the first Turkish lunar regolith simulant

Micro-Raman and FTIR spectroscopic characterization of the first Turkish lunar regolith simulant