In-situ Resource Utilization Research Articles

Electrochemical Oxygen Evolution from Metal Oxides Using Perovskite Anodes Towards Lunar Resource Utilization

In-situ resource utilization (ISRU) has been proposed for realizing sustainable lunar development. One of the representative resources on the Moon is lunar regolith, which covers the lunar surface. The chemical composition of lunar regolith resembles the constituents of the Earth: silica (SiO2) is the most abundant oxides in the lunar regolith. Silicon, which can be produced by silica reduction, will be the material for solar cells, and oxygen is essential for manned space exploration. Enormous amounts of silicon and oxygen will be obtainable on the Moon without transportation from the Earth by establishing silicon reduction methods without consumables. However, the conventional silica reduction method consumes vast amounts of carbon, which cannot be mined on the Moon.For realizing carbon free silica reduction method consistent with the concept of ISRU, molten salt electrolysis processes using perovskite anodes has been researched. In this method, the silica dissolved in molten salts is electrolyzed using voltage with passage of direct current through electrodes, which generate oxygen gas and silicon by the electrochemical process. The perovskite oxides have high electrical conductivity and oxidation resistance. Therefore, the perovskite anodes have been expected as oxygen generation inert anodes.In this study, we report the characteristics of perovskite-type anodes for oxygen generation measured in the electrolysis experiments. In molten fluoride containing silica at a temperature over 500℃, the measured cyclic voltammograms with a perovskite-type anode show drastically increases of current density at 2.6 V vs K+/K, which was approximately same to the oxygen generation potential in the previous molten salt electrolysis result without the perovskite anodes. The characteristics of perovskite-type anodes for oxygen generation will be discussed from the results of electrochemical measurements and chemical analysis using XRD, SEM, EDX, and ICP-AES analysis.

(Keynote) Electrochemical Devices for Lunar Exploration - JAXA's Concept

Japan has decided to participate in the space exploration program "ALTEMIS program" proposed by US. One of the manned mission, Lunar surface exploration using rover (vehicle), is also involved in this program and Japan has started to develop it with JAXA and several companies and planned to be operational by the end of the decade, probably in 2029. The ultimate goal of the project is to help humanity live on the moon by 2040, and eventually on Mars. These plans are summarized in Fig. 1.This project surely supports the resources exploration on the moon as in-situ Resources Utilization(ISRU). The Lunar Cruiser, which alludes to Toyota’s Land Cruiser <https://hypebeast.com/tags/Toyota-Land-Cruiser> SUV, is essentially a fuel-cell-powered mobile laboratory that features living quarters, workstations, and cutting-edge scientific instruments. The pressurized rover is expected to have a “lunar-surface cruising range of more than 10,000 km.” Now, other automobile companies like Honda and Nissan might collaborate with all Japan projects.They have since then been creating virtual reality visualizations, conducting simulations, telecommunication systems for automatic operation and building full-scale models with photovoltaic power generation, advanced battery, and fuel cell. This presentation mainly focuses the energy and electrical system design. Figure 1

Benchmarking and Simulation of Solid-Oxide Steam Electrolysis for Propellant Production in a Vacuum Chamber-Simulated Lunar Environment

NASA and other space agencies have prioritized the development of in-situ resource utilization (ISRU) technology for producing critical materials such as propellants in space. Electrolysis to split water found in lunar, asteroid, and Martian environments provides a pathway for liquid H2 and O2 production, but the challenges of deploying such technology in extraterrestrial environments put an extreme emphasis on minimizing specific energy (measured in kWhelec/kgH2) and system specific mass (system kg/(kgH2/h)). High-temperature, solid oxide electrolysis cell (SOEC) systems have the potential to achieve lower specific energy than conventional liquid-phase alkaline and polymer electrolyte membrane (PEM) electrolysis systems, but this requires efficient thermal integration and minimization of balance of plant loads in order to take advantage of the lower electrolysis voltages for steam (vs. liquid H2O). The high operating temperatures of SOECs, however, require significant system mass for steam generators, heat exchangers for recuperation, and insulation of the electrolysis stack, particularly for space applications where ambient temperatures may be extremely low.This NASA-sponsored collaboration between OxEon Energy and Colorado School of Mines explored the feasibility of a lunar-based SOEC system, which was modeled and demonstrated at the lab-scale by operating a breadboard system, consisting of a SOEC stack and associated balance of plant BOP) in a cryogenic vacuum chamber in order to simulate a lunar environment. The combined »2.5-kWelec SOEC stack and BOP achieved a specific energy < 50 kWhelec/kgH2 at an H2 production rate of > 0.075 kgH2/h operating in the cryo-vacuum chamber.This study has benchmarked system-level models of the lab-scale SOEC stack based on doped-zirconia electrolytes fabricated at OxEon and designed to operate near thermoneutral voltage (1.28 V/cell) at 800°C. The stack BOP includes a steam generator, an oil-free scroll compressor, cathode and anode exhaust recuperators, and a H2 dryer, which uses cold incoming liquid water feeds to cool the cathode exhaust and condense most of the excess H2O in the H2 product stream out. Operation of this demonstration system provides a basis for designing scaled-up lunar fuel production systems of 40 kgH2/h. The success of the lab-scale tests in terms of thermal integration and the benchmarked models suggest a pathway to such a full-scale SOEC system that can achieve < 46 kWhelec/kgH2 with much lower specific mass.Both the modeling and the lab-scale demonstration tests revealed that system specific energy was most sensitive to stack steam utilization, and that achieving < 50 kWhelec/kgH2 required stack steam utilization > 75%. In addition, effective thermal integration that limited the electrical heating primarily to steam generation is critical to minimizing the SOEC-system BOP loads. The stack was shown to run reliably at steam utilizations > 90% with a single pass feed. Efforts will be presented on how to simulate such high utilization at larger scales for full lunar deployment. Additional testing of the lab-scale system in larger cryo-vacuum chambers at NASA during 2023 will allow for further confirmation of thermal management strategies to ensure reliable SOEC operation for lunar production of H2/O2 propellants.

Electrochemical Catalytic Synthesis of CH3OH for In‐situ Resource Utilization

AbstractIn space exploration activities, a large amount of materials needs to be carried, which limits the sustainable development of exploration activities. In‐situ resource utilization (ISRU) is an important means to realize resource recycling and continuous space exploration, which converts space resources into oxygen and hydrocarbon fuels. The traditional ISRU in outer space mainly uses high temperature and high pressure to electrolyze water or reduce CO2, having problems such as low conversion efficiency, high energy consumption, and excessive equipment volume. Here, an electrochemical catalytic synthesis technology based on a microfluidic device is proposed, which can convert H2O and CO2 into O2 and organic matter by electrocatalytic method at room temperature and achieve efficient energy and matter conversion. The gas‐liquid mixing and electrochemical reaction were analyzed. A mathematical model of gas‐liquid two‐phase mixing and microfluidic chemical reaction was established. The research results demonstrate the reliability and efficiency of the microfluidic reaction device designed in this paper for ISRU.

Characterization of Composite Freeze-Dried Aerogels with Simulant Lunar Regolith for Space Applications.

Recently, the goal of space exploration has shifted from the incognito of the solar system to the Moon. Concepts like human permanence on the Moon and thermal protective structures made with ISRU (in situ resource utilization) of raw materials have started to be implemented. By limiting the need to launch supplies from the Earth, the paradigm of spaceflight is changed, privileging the vanguard of the utilisation of resources in situ. Still, the main challenges of surviving the radiation dose and the cryogenic temperatures of the lunar night remain. Recent studies have demonstrated how innovative composite materials can help reduce the temperature stress on exploration vehicles. This research presents the material properties of aerogel insulating materials combined with LHS (lunar highlands simulant) regolith obtained by freeze frying. Organic-based aerogels with different percentages of LHS have been analysed in terms of material, morphology, and thermal properties.

Effects of recycling on polystyrene shape memory polymers for in-situ resource utilization

One-way, thermoplastic shape memory polymers (SMPs) used as actuators for self-folding origami are typically single-use materials that would be decommissioned upon completion of mission objectives. As a result, there exists an abundance of unutilized, single-use SMP waste. In-situ resource utilization (ISRU) and recycling offer solutions for the use and integration of sustainable SMP material infrastructures on Earth and for long-duration space missions. Unfortunately, mechanical recycling causes degradation of material properties. Therefore, it is imperative to quantify the effects of recycling on SMP properties. Herein, we utilize a thermo-mechanical recycling method applied to polystyrene SMPs. After recycling, we conduct Fourier transform infrared spectroscopy, differential scanning calorimetry, and dynamic mechanical analysis to investigate changes to the chemical structure, viscoelastic properties, and shape recovery response of the polymer. The results indicate negligible changes to the viscoelastic and shape recovery properties of the recycled material from one to six recycling sequences (extrusions) when compared to the non-recycled material. The most evident form of deterioration occurred in the physical appearance of the material. Otherwise, the shape recovery performance and thermo-mechanical properties remained consistent after recycling. Therefore, the recovery characteristics (recovery ratio, recovery time, and actuation stress) do not change significantly after six recycling sequences, making this material viable for ISRU applications in space environments.

Spaceflight Logistics Approach to Modeling Aggregated Vehicle Concepts

As space exploration moves toward long-duration, sustainable campaigns, operations such as in-space rendezvous, multiple launches, and in-space rendezvous or In-Situ Resource Utilization plants complicate campaign planning. The field of spaceflight logistics has been developed to perform the logistical planning for these new campaigns in an automated manner. Though previous tools have included aggregated vehicle concepts consisting of multiple vehicles, they have key limitations that may not be able to assess campaigns with more complex vehicle architectures and mission operations. This works aims to address these limitations by formulating a method to include independently operating vehicles that can also operate as an element within a larger stack across various different mission segments. Because of the use of the path-arc formulation, the optimizer has the flexibility to decide to use the independent vehicle stages independently, or within a stack. To prove the usefulness of this formulation, the methodology will be applied to a sample case that uses some of these aggregated space vehicles. In particular, a case study of a government reference Human Landing System mission will be used due to its inclusion of aggregated space vehicles.

The Settlement of Space: Economical and Logistical Drivers and Constraints

This work is part of the BIS SPACE technical project studying long term possibilities for an expansion of industrial civilisation on Earth and in space. This paper traces the potential development of space settlements through four ‘generations’, driven and constrained by various economic, physical, and cultural factors. To provide a context for later work, time scales and orders of magnitudes are estimated together with constraints and drivers for space settlement. Following papers will explore the technology of fast transits within the Solar System required to support the economic model and define a fleet of interplanetary craft, based on flow stabilized Z-pinch fusion engines. Keywords: SPACE Project, In-Situ Resource Utilization, Space Settlement, Fission and Fusion Powered Spaceships, Interplanetary Logistics, Dyson Swarm, Kardashev Type I and II

The Settlement of Space: Economical and Logistical Drivers and Constraints

This work is part of the BIS SPACE technical project studying long term possibilities for an expansion of industrial civilisation on Earth and in space. This paper traces the potential development of space settlements through four ‘generations’, driven and constrained by various economic, physical, and cultural factors. To provide a context for later work, time scales and orders of magnitudes are estimated together with constraints and drivers for space settlement. Following papers will explore the technology of fast transits within the Solar System required to support the economic model and define a fleet of interplanetary craft, based on flow stabilized Z-pinch fusion engines. Keywords: SPACE Project, In-Situ Resource Utilization, Space Settlement, Fission and Fusion Powered Spaceships, Interplanetary Logistics, Dyson Swarm, Kardashev Type I and II

Experimental proof-of-concept of the effect of inlet geometry on excavation forces and their reduction for small-scale continuous excavators

Future in situ resource utilisation (ISRU) lunar mission concepts will require mechanisms that allow the available feedstock–mainly the lunar regolith–to be extracted from the lunar surface. Such extraction techniques in the reduced gravity environment of the Moon will need to minimise excavation forces, due to mass restrictions for robotic landers/vehicles and the large financial implications of placing cargo onto Earth’s satellite. An investigation of necessary excavation forces, both horizontally as well as vertically, for small-scale continuous lunar excavation systems based on their geometric inlet shapes, cutting angles, and digging depths has been undertaken. The use of vibration to disaggregate lunar soil and to reduce the necessary forces is explored as a proof-of-concept. Tests performed in a large analogue testbed have shown that the optimisation of the cutting geometry is crucial, as it inherently influences the necessary forces or even prevents deeper cuts into the soil. Our experiments indicate that shallow cuts (low digging depth) into soil at shallow angles are beneficial, and that the piling up of large surcharge masses must be avoided. Critically, applying vibration to cutting edges seems highly beneficial, as the achievable force reductions of up to 50% in the tested conditions far outweigh the additional power requirements. To make these implications immediately applicable to a wider audience, an estimation of available traction forces for certain robotic vehicles based on their mass is added for comparison.

Investigation of heat transfer processes in multi-sized solar-sintered regolith for lunar ISRU program

Effective Thermal Conductivity (ETC) prediction of sintered lunar regolith plays a crucial role in developing extraterrestrial thermal processing and construction techniques for In-situ Resource Utilization (ISRU) projects on the Moon. Most existing literature has been focused on the packed lunar regolith without considering the sintering mechanism. Herein, we presented a mechanistic model to estimate the ETC of sintered lunar regolith. The Monte-Carlo method was applied to simulate the thermal neck resistance between multi-scaled particles, while the irregular particle geometry was characterized by shape factors. The presented model was experimentally validated by the measured ETC and specific surface area of fabricated lunar simulant samples LMS-1 with various granularities sintered under air, argon gas and low vacuum (10−3 Pa). Furthermore, the heat transfer process within solar sintered LMS-1 bed was simulated coupled with the ETC model. Transient behaviors of microstructure, thermal conductivity and temperature profile during solar heating were simulated iteratively. The simulated temperature profiles at the steady state concur well with measured data obtained from the solar sinter testing with an average Root Mean Squared Error (RMSE) of 5.5%, which performs better than the un-sintered ETC model (RMSE=12.7%). The measured sintered depth was improved by 45% with an optimized particle size distribution (PSD) arrangement.

Additive manufacturing by laser powder bed fusion and thermal post-treatment of the lunar-regolith-based glass-ceramics for in-situ resource utilization

Powder bed fusion is one of the most promising additive manufacturing approaches for in-situ resource utilization (ISRU) in the following lunar exploitation missions. However, the harsh conditions for energy supply and equipment operation on the lunar surface and the amorphization of materials due to rapid heat-cooling cycles could hinder the efforts to produce high-quality lunar regolith-based products. Laser powder bed fusion (LPBF) with large laser spot sizes and low scan speeds were used to print the glassy lunar regolith simulant (LRS) precursors. Then the thermal post-treatment was carried on to transform the LRS precursors into glass–ceramic products. The precursors and glass–ceramic samples' microstructure, mechanical properties, and thermophysical properties were investigated. The results indicated that the acceptable range of volumetric energy density (VED) for the LPBF process of lunar regolith was from 3.5 to 4.3 J/mm3. The porous structure resulting from the large molten pools leads to low thermal conductivities and an acceptable strength compromise. The glassy precursors formed augite phase-dominated LRS glass-ceramics at 823 °C during thermal post-treatment and augite-plagioclase polycrystalline LRS glass-ceramics with better mechanical properties at 1100 °C. The increase of the augite phases precipitation contributed to the strength enhancement, and the grain coarsening caused by the prolonged crystallization process at 1100 °C would reduce the strength. The average compressive strength, fracture toughness, and Vickers hardness of the LRS glass-ceramics could reach 50.71 MPa, 1.49 MPa·m1/2, and 897.91 HV1/15, respectively. This multi-process method of laser powder bed fusion of glass-ceramics can maximize the application potential of the ubiquitous lunar regolith in future in-situ additive manufacturing to produce lunar regolith-based building materials for different stages of future lunar exploitation missions.

Extraterrestrial Electrochemistry - Challenges and Opportunities for Electrolytic in-situ Resource Utilization (ISRU) on Mars

The sustained, long-term exploration of other heavenly bodies in the solar system necessitates the development of technological solutions that will free these missions from the constraints of resupply from Earth. Herein, we focus on electrochemical solutions for in-situ resource utilization (ISRU) that will enable “living off the land” on Mars with a particular focus on life-support and fuel production. The constraints imposed by the operational environment and available resources are examined and some existing (demonstrated) electrolysis solutions are discussed. Building on this, knowledge gaps are identified, and a roadmap is proposed for future research focus at the component and device level.

Benchmarking and Simulation of Solid-Oxide Steam Electrolysis for Propellant Production in a Vacuum Chamber-Simulated Lunar Environment

Federal space agencies across the globe have prioritized development of in-situ resource utilization (ISRU) technology, such as propellants from lunar ice, to support space activities. High-temperature, solid oxide electrolysis cell (SOEC) systems integrated with an efficient balance-of-plant (BOP) have the potential to produce H2 and O2 at specific energy (kWhelec/kgH2) lower than conventional liquid-phase alkaline and PEM electrolysis systems, due to lower voltages for steam electrolysis (vs. liquid H2O). This NASA-sponsored collaboration explored the feasibility of achieving such low specific energy in a high-temperature SOEC system operating in a cryo-vacuum characteristic of permanently shadowed craters on the lunar surface where H2O ice can be found. A lab-scale »2.5-kWelec SOEC stack and BOP achieved a specific energy < 50 kWhelec/kgH2 at a production rate of > 0.075 kgH2/h operating in a cryo-vacuum chamber. System-level simulation models of the lab-scale SOEC stack were benchmarked with experimental tests and used to explore scaling of a system for lunar deployment. The lab-scale tests and scale-up modeling suggest a pathway to a MW-scale SOEC system that can achieve < 46 kWhelec/kgH2 with relatively low specific mass (kgsystem/(kgH2/h)).

Analysis of Small Modular Nuclear Reactor Construction on the Moon

The current goals of lunar exploration include the return of humans to the Moon for scientific activities and the ability to implement lunar in-situ resource utilization (ISRU) for propellant production and construction. Both goals will consume power and one option to meet these power requirements are small nuclear reactors (Kilopower or Pylon). Launching these might not be beneficial in the future as the lunar infrastructure develops and the power requirements grow. The possibility of lunar independence from Earth in terms of ISRU must be considered. This paper discusses the materials used in each nuclear reactor including the fuel, reflector, working fluid, etc. along with lunar abundancy of each element used in these materials. Since no lunar ore mining or material production concepts were found, a review of Earth-based mining and production methods for each material were described. As a result, furnaces, mills/crushers, and fluidized bed reactors can be utilized for various processes in material production. Other processes including leaching, flotation, etc. will need their own machines. In the future, designing multifunctional furnaces and ball mills or crushers can be considered since this will simplify the lunar infrastructure and can be advantageous in the long run decreasing Earth dependency and cost. Keywords: Lunar Resource Utilization, Fission Surface Power, Material Production

Oxychloride Generation by Electrostatic Discharge (ESD) of Martian Dust and Detection by Infrared Spectroscopy

Stable oxychlorides, mainly composed of ClO4–, ClO3–, or their mixture, are significantly enriched on the Martian surface (up to ∼0.5%) compared to Earth. ClO4– and ClO3– have different physicochemical properties and biological activities. They are also important candidates for in situ resource utilization (ISRU) and even the food sources of potential Martian lives. Therefore, it is of great scientific significance to determine the species of oxychlorides, especially the ratio of ClO4–/ClO3– on the Martian surface, not only for Martian environmental evolution and life search but also for Martian resource development. In this study, first, a simulation of oxychloride generation by electrostatic discharge (ESD) of the Martian dust storm was performed under simulated Martian conditions. Second, the spectral features of the Fourier transform infrared attenuated total reflection (FTIR-ATR) spectra and liquid transmission (FTIR-TR) spectra of ClO4– and ClO3– were characterized, and a quantitative model between their IR spectra and their concentrations was built. Finally, the concentration of ClO4– and ClO3– in the ESD reaction product under various reaction times and the ratio of ClO4–/ClO3– was detected and analyzed. Our results provide valuable information for the study of the origin of the mechanism, the scientific estimation of the abundance and the species of oxychlorides on the Martian surface, and even the feasibility of ISRU on the Martian surface.

Multi-robot cooperation for lunar In-Situ resource utilization.

This paper presents a cooperative, multi-robot solution for searching, excavating, and transporting mineral resources on the Moon. Our work was developed in the context of the Space Robotics Challenge Phase 2 (SRCP2), which was part of the NASA Centennial Challenges and was motivated by the current NASA Artemis program, a flagship initiative that intends to establish a long-term human presence on the Moon. In the SRCP2 a group of simulated mobile robots was tasked with reporting volatile locations within a realistic lunar simulation environment, and excavating and transporting these resources to target locations in such an environment. In this paper, we describe our solution to the SRCP2 competition that includes our strategies for rover mobility hazard estimation (e.g. slippage level, stuck status), immobility recovery, rover-to-rover, and rover-to-infrastructure docking, rover coordination and cooperation, and cooperative task planning and autonomy. Our solution was able to successfully complete all tasks required by the challenge, granting our team sixth place among all participants of the challenge. Our results demonstrate the potential of using autonomous robots for autonomous in-situ resource utilization (ISRU) on the Moon. Our results also highlight the effectiveness of realistic simulation environments for testing and validating robot autonomy and coordination algorithms. The successful completion of the SRCP2 challenge using our solution demonstrates the potential of cooperative, multi-robot systems for resource utilization on the Moon.

Global surficial water content stored in hydrated silicates at Mars from OMEGA/MEx

Assessing the water content at the surface of Mars is key to understand the history of water and past climate of the planet but it also is very important for future exploration and potential In Situ Resource Utilization (ISRU). Numerous locations on the surface, known to harbor hydrated minerals, have been detected and their mineralogical assemblages quantified. Based on previous analyses resulting from the modelling of OMEGA near-infrared spectra, we evaluated in this paper the amount of water that could still be stored in those hydrated minerals that were previously characterized. Overall, we find that on average at the surface the hydrated silicates are composed of ∼5 wt% of water with specific regions with >20 wt% localized in 100 m2 areas, that could present a higher ISRU potential. We find that the global amount of water estimated in hydrated silicates corresponds to ∼10−4 Global Equivalent Layer (m) for deposits of 1 m in depth, which represents a lower bound but could still indicate that on the surface the hydrated silicates – as detected by OMEGA (< 1% of the surface) – may not globally be an important sink of water.

Cyanobacteria and Algal-Based Biological Life Support System (BLSS) and Planetary Surface Atmospheric Revitalizing Bioreactor Brief Concept Review.

Exploring austere environments required a reimagining of resource acquisition and utilization. Cyanobacterial in situ resources utilization (ISRU) and biological life support system (BLSS) bioreactors have been proposed to allow crewed space missions to extend beyond the temporal boundaries that current vehicle mass capacities allow. Many cyanobacteria and other microscopic organisms evolved during a period of Earth's history that was marked by very harsh conditions, requiring robust biochemical systems to ensure survival. Some species work wonderfully in a bioweathering capacity (siderophilic), and others are widely used for their nutritional power (non-siderophilic). Playing to each of their strengths and having them grow and feed off of each other is the basis for the proposed idea for a series of three bioreactors, starting from regolith processing and proceeding to nutritional products, gaseous liberation, and biofuel production. In this paper, we discuss what that three reactor system will look like, with the main emphasis on the nutritional stage.

Reliability Optimization of a Mars Oxygen Production Plant

The Mars Oxygen ISRU Experiment (MOXIE) is an instrument onboard NASA’s Perseverance rover. On April 20th, 2021, MOXIE generated oxygen on Mars from the carbon dioxide present in the Martian atmosphere, demonstrating, for the first time, in-situ resource utilization (ISRU) on the surface of another celestial body. Learnings from MOXIE on Mars have aided in the design of a scaled-up version of MOXIE. Oxygen generated from this scaled-up system would be used as propellant in a Mars Ascent Vehicle that would enable the crew to return to Earth once their mission was complete, as well as in life support systems. Failure of any of its subsystems would result in a loss of mission due to the inability of the crew to return to Earth. Accordingly, risk analysis is one of the most crucial steps in the design of the scaled-up MOXIE that must be completed and understood before building and launching the system to Mars. The intent of this paper is to present a comprehensive, quantitative analysis of the operational risks associated with this Mars ISRU plant. We then present an approach to optimize the reliability of each subsystem using a modified probabilistic risk assessment and heuristics-based optimization algorithm.