Lunar ice is a strategically important resource due to its potential to enable in-situ production of propellants for in-space refueling. However, existing remote sensing data are insufficient to determine whether prospective ice deposits meet reserve criteria. This study applies value of information (VOI) theory to investigate the economic rationale for completing ground-based exploration for lunar ice reserves. By investigating a range of potential extraction and exploration scenarios, the analysis demonstrates the utility of linking VOI to cash flow models as a framework for evaluating future missions. This study finds that uncertainties in deposit composition and technology performance are primary factors undermining the business case. Lunar-sourced propellant could yield positive net present value (NPV) outcomes-even with low propellant prices and launch costs. In representative future scenarios, the VOI from ground-based exploration is likely to exceed mission costs, suggesting that such campaigns can be economically justified.

Utilizing water ice from the lunar permanently shadowed regions (PSRs) is essential for sustainable space exploration. This study explored the optimization of thermal mining methods for in-situ water ice extraction, focusing on how to adjust the configuration of heating rods to meet the flexible operational needs on the Moon, alongside the effects of water ice particle size and heating temperature. Our findings suggest that optimizing the heating temperature according to the water ice particle size and arrangement of heating rods significantly improves extraction performance. Specifically, by maintaining the water ice particle size greater than 20 mu m, we increase the thermal conductivity of the regolith-ice mixture by approximately 135 % compared to dry regolith, greatly shortening the extraction time. Notably, precise control of extremely low heating temperatures allows for significant expansion of the extraction range of a single heating rod. In scenarios where time constraints are minimal, the extraction range can be significantly expanded. Our innovative approach, grounded in fundamental heat transfer principles, demonstrates broad applicability and potential extension to water ice extraction on other celestial bodies. These findings provide a crucial foundation for efficient lunar resource utilization, satisfying the critical needs of future lunar missions and advancing human presence on the Moon.

Permanently Shadowed Regions (PSRs) of the Moon contain rich deposits of water ice. They are very valuable to the space community as in-situ extracted water can be used for many purposes, such as propellant production and human habitat support. PSR craters never see sunlight, therefore solar power is not available there. They also present a cryogenic environment with regolith as cold as 40 K. These challenges can be overcome by employing a Radioisotope Power System (RPS) to provide both thermal and electrical power to resource extraction systems in the PSRs. The work presented here aims at characterizing an ice-mining lunar rover. The rover will be equipped with an Americium-241 (or 241Am) based RPS. 241Am has a 432-year long half-life and can provide decades of stable power output for the rover operations. The innovation lies in the fact that the RPS will not only provide electrical power to the rover, but that its waste heat will be employed to thermally mine ice from its deposits. The rover is equipped with a sublimation plate irradiating the underlying regolith to sublimate ice contained within, and with a cold trap where extracted volatiles will be deposited. This work studied the rover concept feasibility and developed a model of its Thermal Management System (TMS) to meet sublimation plate and cold trap temperature requirements. The results have been validated by a 3D finite element method thermal simulation for icy regolith conditions of 0-10 vol% water-ice content. The findings of this work suggest that it is possible to perform thermal ice-mining in the lunar PSR environment with an RPS-powered rover, with different degrees of efficiencies depending on the amount of ice in the deposits.

The Moon's polar regions have abundant water ice resources. The mining and utilization of lunar polar water ice could serve as a propellant and survival resource for human exploration of deep space. The concept of thermal mining has been proposed to extract water ice resources. There are advantages and disadvantages to different mining methods. The energy problems faced by in situ resource utilization on the Moon are of great concern. The electrolysis of water and the heating of weathered layers require a continuous supply of energy. Wired energy transfer at the lunar poles would be very costly for launching conductors from Earth to the Moon. Wireless energy transfer technology is also well-developed today and has promising applications in the energy supply of lunar thermal mining. This paper describes the different methods of thermal mining and the various ways of supplying energy using solar energy for thermal mining. (c) 2024 COSPAR. Published by Elsevier B.V. All rights reserved.

Lunar in-situ water ice utilization is considered an essential part of the future construction of Lunar Bases. However, the thermal conductivity of lunar regolith without water ice is extremely low, which seriously hinders the thermal mining of lunar water ice. In this study, we proposed a novel approach to optimize the energy ef-ficiency of water ice thermal mining. In this method, a constant temperature heat source with a heating tem-perature selected according to the particle size of water ice was used to slow down the reduction rate of the thermal conductivity of icy soil. Our simulation results showed that the relatively high mining temperature led to the rapid sublimation of water ice near the heat source, reducing the thermal conductivity of the icy soil and the energy efficiency.A relatively low mining temperature decreases the sublimation speed of water ice and reduces energy effi-ciency. The particle size of water ice determined the decreasing rate of thermal conductivity of icy soil, thus affecting its optimum heating temperature. Using a constant temperature heat source at the optimal heating temperature, the energy efficiency of water ice mining could be increased by several orders of magnitude compared with constant power heating.

It is of great significance to realize the in-situ utilization of lunar water ice for the establishment and sustainable operation of the future lunar base. Considering the location of water ice in the lunar polar regions, based on the in-situ thermal mining method, an integrated approach for the water ice recovery was established. The evolution characteristics of average temperature of the icy soil and water vapor collection rate with the mining time were analyzed. The optimal mining temperature for the recovery of water ice was studied. The energy efficiency under various arrangement densities of heating elements was assessed with the optimal number of heating elements determined. The results show that as the mining time increases, for different target mining temperatures, the average temperature of the icy soil rapidly rise at first, and then tend to stabilize. The water vapor collection rates at different target mining temperatures vary greatly due to the difference in saturated vapor pressure of water ice. At high mining temperatures, the sublimation coefficient also significantly affects the process of water vapor collection. The water vapor collection rate with sublimation coefficient being unity is up to 36% larger than that with non-constant sublimation coefficient for the lunar soil under investigation within four earth weeks at the target mining temperature of 240 K. In addition, the increase of the mining temperature increases the water vapor collection rate, and at the same time, the water vapor pressure in the capture tent also increases, which may lead to the instability of the water ice production system. Combining with water vapor collection rate and change rate of water vapor pressure in the capture tent, the temperature of 220 K is obtained as the optimal target mining temperature. Furthermore, for the lunar soil in this work, the energy efficiencies for water ice production with seven and nine heating elements are same, and greater than that with five heating elements. Considering the energy efficiency, the minimum number of heating elements could be determined.

Thermal mining is a promising architecture, which may provide reliable and 'dirt-simple' means of production of space-sourced water, oxygen and rocket propellant in the future. It is especially tailored to water ice deposits that exist within lunar Permanently Shadowed Regions, where our quest for riches of the Outer Space might begin. Here, the thermal mining extraction system is simulated and analysed with combined heat and mass transfer FEM modelling. The results exhibited that water extraction on the Moon might follow specific production phases, which closely relate to changes in the sublimation interface movement over large timeframes. The production behaviour on the Moon might have many characteristics of relevant production systems on Earth. This may open door for many well-established terrestrial models and production projections to be refitted to extraterrestrial case. It was found that the required water yields of the thermal mining architecture, which make its case economically and commercially viable, are hard to reach without production optimization and new systems development. The production is projected to be significantly hindered by sublimation lag build-up, which would create thermal insulation for the icy deposits. Sublimation lag removal and other strategies might be the answer to that problem.