Lunar In-Situ Resource Utilization Research Articles

Mars In Situ Resource Utilization (ISRU) with Focus on Atmospheric Processing for Near-Term Application—A Historical Review and Appraisal

The inspirational paper by Ash, Dowler, and Varsi in 1978, proposing to utilize in situ resources on Mars (ISRU) rather than bringing them from Earth, originated the field of Mars ISRU that has been the subject of research ever since. In this paper, we reviewed significant research reported on Mars ISRU since 1978 and reported briefly on accomplishments. We found that prior to 2014, progress on small tasks was sporadic and intermittent, always at low Technology Readiness Level (TRL). In 2014, the National Aeronautics and Space Administration (NASA) took a bold, imaginative, unprecedented step to fund a major project in Mars ISRU: the so-called “MOXIE” (Mars Oxygen In Situ Experiment), in which an oxygen production plant based on solid oxide electrolysis (SOEC) was developed, and finally demonstrated on Mars in 2022 and 2023. While MOXIE leaves behind it a wealth of accomplishments, there remains the need to close remaining gaps with additional laboratory and field work. Solid-oxide electrochemical cell (SOEC) technology has become a major area of worldwide investment for terrestrial energy and CO2 control. There is a very strong overlap between this terrestrial technology and Mars ISRU. NASA has already leveraged the terrestrial development work via MOXIE. NASA can leverage further advances with a comparatively small investment beyond 2023. Because NASA is engaged in a major program to return humans to the Moon, NASA’s focus is on lunar ISRU. Unfortunately, the mission impact and return on investment for lunar ISRU does not compare to that for Mars ISRU. NASA’s concept for Mars ISRU is futuristic, involving autonomous mining, transporting, and processing large amounts of Mars regolith. This might well occur long after initial human landings which could better profit in the near-term from MOXIE technology. By continuing further development of SOEC technology beyond MOXIE, while leveraging large investments in terrestrial applications, NASA can develop the Mars ISRU appropriate to nearer term human missions at modest investment. The goal of this paper is to place the relatively mature MOXIE technology advance and solid oxide electrolysis in general in perspective to the historical evolution of low TRL Mars ISRU technology.

Composition-property relationships of BP-1 lunar regolith simulant geopolymers for in-situ resource utilization

In-situ resource utilization (ISRU) to construct environmental protection and critical infrastructure is required for long-term human habitation on the Moon and Mars. Analogous to terrestrial construction materials formed from aluminosilicates, i.e., geopolymers, construction materials formed from lunar aluminosilicate regolith are a promising method to create lunar landing pads and habitats. Building on a previous lateral study across multiple regolith simulants, the effects of composition on one specific regolith simulant, Black Point 1 (BP-1), are investigated with the goal of developing relationships between composition and properties. The effects of overall geopolymer composition, activating solution silica and sodium content, and activating solution water content on seven-day compressive strength, strain to fail, and secant modulus are investigated. Decreasing water content has a positive effect on compressive strength and secant modulus of geopolymers formed at ambient-earth conditions, reaching maximum compressive strength at 75 wt% BP-1. Above a compositional limit of Si/H2O = 0.6, differences in Si and Al coordination result in variations in compressive strength with the elemental composition of the geopolymer. At high solids in formulation, the observed trend in compressive strength is nonmonotonic with varying silicon and aluminum content, emphasizing the need for a mechanistic understanding of the relationship between composition and structure for optimization of geopolymer material properties. This study provides a robust set of data for a widely available lunar regolith simulant that can guide further development of processing strategies for lunar ISRU.

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.

Quantitative Inversion of Lunar Surface Chemistry Based on Hyperspectral Feature Bands and Extremely Randomized Trees Algorithm

In situ resource utilization (ISRU) is required for the operation of both medium and long-term exploration missions to provide metallic materials for the construction of lunar base infrastructure and H2O and O2 for life support. The study of the distribution of the lunar surface elements (Fe, Ti, Al, and Si) is the basis for the in situ utilization of mineral resources. With the arrival of the era of big data, the application of big data concepts and technical methods to lunar surface chemistry inversion has become an inevitable trend. This paper is guided by big data theory, and the Apollo 17 region and the area near the Copernicus crater are selected for analysis. The dimensionality of the first-order differential spectral features of lunar soil samples is reduced based on Pearson correlation analysis and the successive projections algorithm (SPA), and the extremely randomized trees (Extra-Trees) algorithm is applied to Chang’E-1 Interference Imaging Spectrometer (IIM) data to establish a prediction model for the lunar surface chemistry and generate FeO, TiO2, Al2O3, and SiO2 distribution maps. The results show that the optimum number of variables for FeO, TiO2, Al2O3, and SiO2 is 17, 5, 8, and 30, respectively. The accuracy of the Extra-Trees model using the best variables was improved over that of the original band model, with determination coefficients (R2) of 0.962, 0.944, 0.964, and 0.860 for FeO, TiO2, Al2O3, and SiO2, and root mean square errors (RMSEs) of 1.028, 0.672, 0.942, and 0.897, respectively. The modeling feature variables and model preference methods in this study can improve the inversion accuracy of chemical abundance to some extent, demonstrating the potential of IIM data in predicting chemical abundance and providing a good data basis for lunar geological evolution studies and ISRU.

Overview of lunar exploration and International Lunar Research Station

As the only natural satellite of the Earth, the Moon is the first target for human space exploration, due to its unique location, highly characteristic environmental resources and abundant material resources. The Earth-Moon system is the proving ground for the exploration of the solar system, and the Moon is a transit point towards farther deep space. Lunar science plays an important role in promoting the development of space science. The development and utilization of lunar resources is of great significance to the sustainable development of mankind. In recent years, China’s lunar exploration has achieved remarkable achievements. After completing the three steps strategy of “orbiting, landing and sample return”, it will aim to better serve the lunar scientific exploration and in situ resource utilization (ISRU), to enhance human scientific cognition and expand Human living space, and to serve the sustainable development of human society. This paper reviews the status and trend of Chinese and international lunar exploration, and summarizes the main tasks, cutting-edge scientific questions and key technologies involved in future lunar exploration and puts forward recommendations for the development of the Chinese lunar exploration. Driven by lunar scientific exploration and lunar ISRU, the International Lunar Research Station (ILRS) aims to create infrastructure and shared platforms for solving key space science questions, effectively using lunar resources, and developing the Earth-Moon Economic Circle. In this article, the main mission requirements, and functional architecture of the station are analyzed. A three-step construction plan is proposed, involving (1) making good use of planned missions; (2) coordinating home and abroad missions; and (3) seeking for joint missions. In the first stage, relying on series missions of the fourth phase of China Lunar Exploration Program, we will carry out international cooperation and build up the basic type of the ILRS with capabilities of exploration under a long-term scale and complex environmental conditions. The ILRS will contribute to polar region scientific exploration, ISRU, and application verification for the future expansion. In the second stage, international lunar missions will be coordinated with the objective of expanding the scale, and the technical and scientific activities of the ILRS, therefore making a breakthrough in multi-national and multi-module collaborative work and in integration management or other key technologies. Key technologies, including the long-term operation and guarantee of future scientific research stations, and the application of lunar resource, will be mastered. In the third stage, international partners will contribute to upgrade the station in support of long-term and large-scale scientific exploration, technical experiments and the utilization of lunar resources by jointly investment of new missions. New era of human space exploration will be cultivated, and space physics, astronomy, planetary geology, planetary chemistry and other disciplines will be promoted by international cooperation. International cooperative methods planning integration, joint demonstration, mission design, technical cooperation, collaborative implementation, and achievement sharing are analyzed, all of which paving the way for the demonstration and implementation of the international big scientific projects the ILRS. At present, ILRS has become China’s first batch of international major scientific engineering cultivation projects. Along with international partners, China will carry out scientific objective research, engineering feasibility demonstration and joint implementation plan. Organizational management models and operating mechanisms will be proposed, international expert team and international implementation team will be established, on the basis of which the cultivation of the large-scale scientific project the ILRS will be completed under the principle of wide consultation, joint contribution and shared benefits.

Commercial viability of lunar In-Situ Resource Utilization (ISRU)

In this paper, we propose an architecture for lunar in-situ resource utilization (ISRU) which can provide propellant, typically cryogenic hydrogen and oxygen, to a cislunar aggregation point in support of future space missions to the Moon, Mars, and beyond at a price competitive with commercial delivery from Earth. This architecture is premised on maximizing the non-linear scaling laws of key system components: the ISRU plant, the nuclear reactor, and the reusable lunar lander. Engineering and cost models were developed to evaluate the impact of non-linear scaling laws on a reference architecture. The scaling laws applicable to each key system component were evaluated and incorporated in our model. We also provide sensitivity analysis showing how the model is impacted by commercial delivery costs to the cislunar aggregation point. This study showed that the cost of propellant sourced from lunar ISRU production can be lower than that delivered from Earth when maximal scale is utilized in sizing the key system components.

TUBS-M and TUBS-T based modular Regolith Simulant System for the support of lunar ISRU activities

Rising international interest in scientific and commercial Moon exploration programs require cost-efficient logistical solutions regarding raw- and construction materials for a permanent residence on our Earth’s satellite. Lunar regolith soil is the most abundant resource; its technical exploitation would comprise a major leap forward towards the construction of infrastructure on the Moon. Current efforts dedicated to the technological exploitation of lunar regolith require terrestrial analogue materials (simulants). Such simulants are indispensable for Earth-based development and testing of hardware later used on the lunar surface (e.g. rovers or scientific equipment) as well as technologies that will process regolith directly. However, available simulants are material-specific which limits their use to tests for site specific projects on the lunar surface. At TU Braunschweig, we are actually developing a regolith simulant system that allows the flexible adaptation of regolith properties to meet the technological testing requirements. That planned process for the production of customized simulants is presented in the paper. The TUBS-M and TUBS-T simulants are based on basaltic and anorthositic bedrock, respectively. These two basic simulant components, which match the two dominant lunar surface rock types, are now fully developed. Their characteristics in terms of mineralogy, chemical composition, and physical properties are presented in this paper. Currently, methods for the production of other important components of the regolith (glasses, agglutinates) are in development and additional minerals will be analyzed, which will enable the production of highly customized simulants for in-situ resource utilization (ISRU) purposes beginning in 2020.

Prototype Development of an Integrated Mars Atmosphere and Soil-Processing System

The concept of living off the land by using the indigenous resources of the Moon, Mars, or other potential sites of robotic and human exploration has been termed in situ resource utilization (ISRU) and will be an enabling technology to open up the solar system. Although the most recent National Aeronautics and Space Administration (NASA) human Mars mission study (Design Reference Architecture 5.0) showed that production of propellants and life support consumables was a mission-enabling capability, mission planners were hesitant to select the newly proposed water extraction from Mars soil option because of the perceived high risk associated with this approach. To overcome resistance in putting ISRU capabilities in the critical path of mission success, NASA ISRU developers have adopted the approach of designing and building hardware into end-to-end systems at representative mission scales and testing these systems under mission-relevant conditions at analog field test sites. Previous ISRU field demonstrations have been standalone lunar ISRU modules running on alternating current power with nonoptimal integration. The primary goal of the Mars atmosphere and regolith collector/processor for lander operations (MARCO POLO) project is to design, build, and test an end-to-end first-generation Mars ISRU atmospheric and soil-processing system powered by mission-relevant direct current power while also demonstrating closed-loop power production via the combination of a fuel cell and electrolyzer. A secondary goal is to perform remote and autonomous operations with this integrated system on a 3×3-m(∼9×9-ft) octagon lander and transfer oxygen and methane produced to a cryocart for use with a thruster to demonstrate an end-to-end Mars resource-to-thrust concept. This paper will outline the overall design, technologies used, and concept of operations for the MARCO POLO project and its upcoming field demonstration.

Progress Made in Lunar In Situ Resource Utilization under NASA’s Exploration Technology and Development Program

AbstractIncorporation of in situ resource utilization (ISRU) and the production of mission-critical consumables for propulsion, power, and life support into mission architectures can greatly reduce the mass, cost, and risk of missions, leading to a sustainable and affordable approach to human exploration beyond Earth. ISRU and its products can also greatly affect how other exploration systems are developed, including determining which technologies are important or enabling. Although the concept of lunar ISRU has existed for more than 40 years, the technologies and systems had not progressed much past simple laboratory proof-of-concept tests. With the release of the Vision for Space Exploration in 2004 with the goal of harnessing the Moon’s resources, the National Aeronautics and Space Administration (NASA) initiated the ISRU project in the Exploration Technology Development Program (ETDP) to develop the technologies and systems needed to meet this goal. In the 5 years of work in the ISRU Project, signific...

Solar Thermal Power for Lunar Materials Processing

Lunar in situ resource utilization (ISRU) processes require thermal energy at various temperatures. Chemical recovery processes (pyrolysis, gas-solid reactions, gas-liquid or three-phase reactions and desorption) require thermal energy at temperatures from 1,000 K to 2,500 K . Manufacturing processes (hot liquid processing, sinter forming, composite forming, welding, etc.) can be accomplished with thermal energy at temperatures 1,200 K–1,800 K . For these materials, process applications or solar thermal power can be effectively utilized. Physical Sciences Inc. has been developing an innovative solar power system in which solar radiation is collected by the concentrator, which transfers the concentrated solar radiation to the optical waveguide transmission line made of low loss optical fiber. In this paper, we will review our work on the development of the solar thermal power system and its application to a lunar ISRU process.