Moon Fuel Depot Requires Massive Power: 24 kWh per Kilogram of Oxygen

humanity’s next leap into the Solar System hinges on solving a practical problem: how to fuel rockets beyond Earth’s gravity well without dragging a mountain of propellant from the home planet every time. A growing chorus of experts argues that producing rocket oxygen on the Moon could be a cornerstone of that strategy. A recent energy analysis focuses on a specific, well-studied mineral abundant on the Moon—ilmenite, an iron titanium oxide—embedded in the lunar regolith. The study asks a simple but powerful question: how much electrical power would it take to extract usable oxygen from that mineral at meaningful industrial scales? The result is a surprisingly concrete number—roughly 24 kilowatt-hours of energy per kilogram of liquid oxygen produced—but the implications are anything but simple. The energy cost sounds modest in isolation, yet the volume of oxygen required to support deep-space missions, the logistics of deploying lunar infrastructure, and the choice between solar and nuclear power all compound into a complex feasibility calculation. This article unpacks the argument, the chemistry, the infrastructure logic, and the energy economics behind lunar oxygen production that could one day feed a fleet of spacecraft venturing beyond Earth.

The promise and the problem of lunar refueling

If humanity is to extend its reach into the Solar System, the ability to refill spacecraft away from Earth’s gravity well could be a decisive enabler. Refueling in low-Earth orbit has the advantage of proximity to launch pads and heavy infrastructure. But escaping Earth’s deep gravity well remains an energy-intensive, mass-heavy challenge. Launching propellant into orbit requires a substantial portion of a rocket’s mass budget simply to deliver the fuel that will burn on the way to the Moon or beyond. The energy costs of moving propellant itself from Earth to the point where it will be used for a mission subtract from the payload fraction and complicate mission planning.

An alternative has appeared in the literature and in mission concepts: producing fuel on the Moon. The Moon’s weaker gravity and lack of a dense atmosphere make it easier to lift material off its surface compared with Earth. More crucially, abundant hydrogen and oxygen—two pillars of rocket fuel—are believed to be present in lunar materials, particularly in the regolith. If oxygen can be extracted and hydrogen recovered locally, the propulsion system could be replenished with a resource that is momentarily more accessible in space than it is on Earth. If the oxygen can be produced near the Moon, the next logical step is to transmit or transport fuel to a staging point in space, where it can be used to propel missions farther into the Solar System with a smaller energy penalty.

But there is a catch. Producing oxygen from lunar materials is not free. Any drive to industrial-scale lunar oxygen production must account for the energy required to convert lunar minerals into usable oxygen, as well as the energy costs of gathering, purifying, and processing those materials. A recent energy assessment zeroed in on a mineral that is abundant on the Moon and lends itself to known chemical pathways: ilmenite (FeTiO3). The researchers offered a rigorous, if focused, energy budget for extracting oxygen from ilmenite-rich regolith. Their core finding is stark: at typical process conditions and with plausible assumptions, the energy requirement hovers around 24 kilowatt-hours per kilogram of liquid oxygen produced. To appreciate what that means, we need to connect this number to the scale of oxygen needed for lunar and deep-space missions, the energy infrastructure that would be deployed on the Moon, and the time scales of production given different power sources.

The broader context is clear. If lunar oxygen production becomes a practical source of rocket oxidizer, a suite of interdependent decisions will determine whether the Moon becomes a true fuel depot or a costly, interim step. The energy cost per kilogram of oxygen is a critical piece of the puzzle, but it sits inside a larger matrix that includes:

• How efficiently the raw regolith can be processed to retrieve ilmenite.
• The concentration of ilmenite in target lunar soils and the geographic distribution of high-concentration deposits.
• The efficiency of subsequent chemical steps that release oxygen from ilmenite and the surrounding minerals.
• The availability and cost of power infrastructure on the Moon, including solar and potential nuclear options.
• The integration of oxygen production with hydrogen production, storage, and delivery to rocket engines.
• The logistical challenge of transporting materials, equipment, and oxygen from production sites to refueling points or mission launch sites.

In short, the energy cost per kilogram of oxygen cannot be judged in isolation. It must be weighed against the mass and cost of the infrastructure required to reach, harvest, purify, process, and deliver the oxygen, as well as the broader mission economics, including how often production must occur to support a given fleet of missions.

The ilmenite pathway: turning regolith into oxygen

The crux of the ilmenite-based approach is straightforward in concept but intricate in execution. The plan begins with lunar regolith—the fine dust and soil that blankets much of the Moon’s surface and has formed through eons of micrometeoroid impacts. Within this regolith lie a variety of minerals, many of which contain oxygen bound in oxides. The researchers focus on ilmenite, a mineral that contains iron, titanium, and oxygen in a stable lattice. Ilmenite is not the simplest oxide to release oxygen from; iron oxides often yield oxygen more readily, but ilmenite is particularly appealing because of its abundance and the well-understood chemistry behind its treatment.

The proposed system envisages several key stages:

1. Harvesting regolith and isolating ilmenite: The first step is to collect lunar soil and separate the portion that contains ilmenite. Realistically, this involves a combination of mechanical excavation, screening, and mineralogical separation to enrich the ilmenite content in the processed material while filtering out nonreactive silicates and other contaminants. The study assumes that a portion of the regolith will be suitable for the chemical steps and that purification methods will be capable of enriching ilmenite to a level where the subsequent reactions proceed efficiently.

2. Partial purification of ilmenite: The process includes a partial purification of ilmenite to reduce impurities that would otherwise absorb heat, carry unwanted heat, or otherwise complicate the high-temperature chemistry. The assumption is that a fraction of the ilmenite is sufficiently pure to participate effectively in the subsequent reaction sequence, and that the purification step will be efficient enough to deliver material with predictable behavior in the reactor.

3. High-temperature reaction with hydrogen to form water: The purified ilmenite is then subjected to a high-temperature reaction in the presence of hydrogen. In this step, oxygen is liberated from the mineral via chemical interaction with hydrogen, producing water and leaving behind iron and titanium as byproducts. This reaction is the dominant energy sink in the process, accounting for roughly more than half of the total energy consumption observed in the analysis. The reaction chemistry is well understood in a laboratory sense, but translating it to industrial-scale processing on the Moon requires careful consideration of heat transfer, phase changes, material durability, and the handling of reactive gases in a lunar environment.

4. Water processing and oxygen separation: The water produced in the hydrogen reaction is then split electrochemically (or via a comparable chemical route) to yield hydrogen gas again and gaseous or liquid oxygen. In the study, this step accounts for a substantial portion of the energy budget, nearly 38 percent of total energy consumption, as electricity or another energy form is used to drive the water-splitting process. The produced hydrogen is recycled back into the system to sustain a closed loop for the hydrogen-reaction stage, while the liberated oxygen is captured for propulsion needs.

5. Oxygen liquefaction and storage: The final transformation involves cooling the gaseous oxygen into its liquid form for high-density storage and efficient loading onto rockets. This liquefaction step, while not the largest energy sink in the sequence, still consumes energy and contributes about 5 percent of total energy consumption. The design considerations for this stage include cryogenic equipment, insulation, environmental control for lunar conditions, and safety measures for handling cryogenic oxygen in a permanently inhabited or semi-inhabited lunar base.

The researchers deliberately focus on a single element pathway to provide a clear energy picture. This is not a wholesale claim that ilmenite is the only or final path to lunar oxygen, but rather an analytically tractable route that helps quantify what the energy demands would look like at scale. They acknowledge several simplifying assumptions that affect the energy tally:

• They assume that ilmenite can be purified from raw regolith to a level that yields usable oxygen in workable quantities. The extent of purification required and the practical limits of purification in a lunar environment remain open questions for future engineering studies.
• They assume that about half of the available material participating in the chemical reactions would actively contribute to the process, a baseline that balances material heterogeneity with practical reactor design.
• They acknowledge that the study does not exhaustively examine other oxygen sources present in the regolith, nor does it account for potential contamination from substances like hydrogen sulfide or hydrochloric acid that might complicate the chemical pathway.
• The analysis focuses on the energy intensity of the core steps rather than the full engineering costs of building and operating all supporting systems, such as harvesters, material transport equipment, high-temperature reactors, separation hardware, gas handling systems, and cryogenic plants.

Taken together, these points yield a total energy requirement of about 24 kilowatt-hours for each kilogram of liquid oxygen produced. The number itself is a signal of energy intensity, not a final verdict on feasibility. It is sensitive to several variables, including how efficiently heat is delivered and removed (i.e., the heat management of the reactor), how effectively ilmenite is separated from other regolith components, and how efficiently heat sources are deployed. The study’s authors explicitly note that it is possible to explore alternatives, such as using solar thermal energy to drive the heat-intensive steps, which might reduce or even replace electricity use in high-temperature stages. However, that variant was not analyzed in their energy accounting, leaving an important avenue for further research open.

The ilmenite-centric pathway also benefits from a geographical insight. Orbital observations suggest that some areas on the near side of the Moon host elevated concentrations of ilmenite, especially within certain mare regions. These locales are logistically attractive because they are relatively easier to access from a lunar base with robotic mining activities and could reduce the mass and energy costs associated with material transport from a central mining site to the processing plant. While the study does not map every deposit in exact geospatial terms, it does outline a reasoned expectation that ilmenite-rich pockets may be present in locations that are more favorable for early infrastructure deployment. That said, there is still considerable uncertainty about the precise distribution and contamination of ilmenite deposits, which would affect capital costs, production scale, and the energy footprint of any real system. The fact remains that if ilmenite is abundant enough in accessible regolith, then the outlined approach could become a credible near-term blueprint for lunar oxygen production, while if ilmenite is more sparse than expected, the economics could shift toward alternative oxide-bearing minerals or different extraction pathways.

How much oxygen do we actually need, and what does energy per kilogram imply?

Even with a concrete energy budget per kilogram, translating that into mission viability requires a broader look at how much oxygen would be needed for real missions. A useful rough comparison emerges when considering the oxygen demand of a large, fully fueled spacecraft. In the scenario explored by the study, an empty SpaceX Starship—an exemplar of a modern, heavy-lift vehicle—requires around 80 metric tons of liquid oxygen to depart from a lunar surface and reach the Earth–Moon Lagrange Point. For guidance, a Starship loaded with propellant—a fully fueled configuration—can carry well over 500 tonnes of liquid oxygen. The stark reality is that even a moderately large lunar oxidizer production facility would need to generate many tens of tonnes of LOX to be meaningful for supporting routine launches, and the cumulative energy cost would scale accordingly.

The energy-in-action translation further clarifies the challenge. If we compare to a large, ground-based power source such as a solar array on a space station, we can derive a rough production rate for oxygen: a 100-kW solar installation could power the production process at a throughput of about four kilograms of oxygen per hour under the study’s baseline assumptions. That rate means roughly one tonne of liquid oxygen would require about ten days of continuous operation under an unbroken solar-energy regime. For a single lunar day of production, the near-side location would only be productive for roughly half the time. That halves the daily throughput and complicates the economics of achieving mission-ready oxygen in time for launch windows.

These numbers do not merely illustrate a bottleneck; they highlight a functional reality of lunar industrialization. Even with optimistic production rates, the lunar day-night cycle reduces effective operating time unless continuous power is supplied by a non-solar source, such as a nuclear reactor designed specifically for lunar operations. The authors discuss this possibility: a robust nuclear power system would enable uninterrupted production, significantly increasing the mass of oxygen produced over a given period, and thus reducing the lead time for outfitting a mission with lunar-sourced oxidizer. The challenge, of course, is the scale of infrastructure required to support continuous operation, including shielding considerations, heat management in a lunar environment, and safety protocols for handling large quantities of cryogenic oxygen on the Moon.

And yet, even if solar power scales up to larger arrays, the production pace still hinges on the energy density of the heat-intensive steps and the efficiency of separating ilmenite from regolith, because these factors largely drive the energy budget. If separation and purification are made more efficient, the energy cost per kilogram drops correspondingly, and the throughput increases for a given power input. Conversely, if separations are less efficient or temperatures are difficult to maintain, energy losses rise and the process becomes more expensive. Crucially, the energy accounting emphasizes that the biggest energy sink is the high-temperature hydrogen reaction that generates water, followed by the water-splitting step, with the liquefaction step being comparatively small in energy share. This hierarchy suggests that any engineering solution that reduces the heat-load, improves heat transfer, and enhances catalytic efficiency for the hydrogen reaction could yield outsized improvements in overall energy efficiency.

The broader takeaway is nuanced: 24 kWh per kilogram is a useful yardstick, but it does not automatically guarantee viability or infeasibility. It does, however, shape the boundary conditions for system designs. If the lunar oxygen economy were to scale toward meaningful mission support, it would require a combination of high-concentration ilmenite deposits, highly efficient separation and purification technologies, robust and reliable high-temperature reactors capable of working in a harsh lunar environment, and power sources that can sustain continuous operation. Solar power could be the first stage of this transition, with nuclear power serving as the facilitator of around-the-clock production as the system scales to multi-tonne oxygen outputs. The energy budget also interacts with the logistics of provisioning the Moon itself: the energy needed to transmit, assemble, and maintain the equipment would be a continuous cost, as would the energy and material inputs required to maintain the production chain, recover hydrogen for reuse, and manage byproducts.

The lunar landscape of ilmenite: where to build the refinery

An essential element of any realistic plan is the geological map of where ilmenite concentrates are sufficiently high to justify a mining operation. The study leverages orbital observations to highlight prospective zones on the near side of the Moon, particularly in mare regions, where ilmenite concentrations are more favorable. The strategic logic is clear: closer proximity to Earth could translate into lower logistics costs for launches and maintenance, and the Moon’s near side provides a more predictable lighting environment for solar-power-based operations during long mission campaigns.

If these deposits prove substantial, the early lunar base could establish a points-based network of mining facilities that feed a centralized or semi-centralized oxygen production complex. In practice, this means a few lunar bases or rovers could harvest regolith, feed it into mobile or semi-mobile processing units, and deliver concentrated ilmenite to a centralized reactor. The centralized approach could improve process control, enable easier maintenance, and allow for easier heat management and power distribution. However, it also raises concerns about transport distances, the reliability of autonomous mining and refining equipment in a hostile environment, and the risk of single points of failure in a centralized system.

A critical unknown remains: the precise distribution and concentration of ilmenite in the lunar regolith. Orbital data provide a credible indication that certain near-side mare regions possess higher ilmenite content, which could guide initial mission planning. Yet, without in-situ verification through robotic or human exploration, there is a degree of uncertainty that can only be resolved by incremental exploration and testing. The early stage, in this view, would likely involve small-scale pilots that validate the separation and refining steps, assess corrosion and wear in high-temperature equipment in the lunar environment, and confirm the expected energy costs in real hardware rather than laboratory models alone.

From an engineering perspective, the near-side mare deposits offer a favorable mix of accessibility and potential abundance, but any shift in the deposit quality could necessitate re-architecture of the processing plant geometry, the storage regime for oxygen, and the proximity of power plants to the mining and refining operations. The footprint of these facilities—industrial-scale reactors, hydrogen supply systems, cryogenic oxygen storage, and associated material-handling equipment—would be significant. The mass and volume of such a facility would not only require careful allocation of lunar surface real estate; it would also demand robust structural design to withstand micro-meteoroid bombardment, extreme temperature cycling, and dust-related abrasion.

Subsectionally, there would be a need to plan for redundancy and fail-safes in extraction lines, separation units, and heat-exchange loops. The lunar environment presents unique challenges: low gravity, extreme diurnal temperature variation, pervasive regolith dust, and potential hydrogen embrittlement in materials exposed to high temperatures and reactive gases. Each of these factors would shape the choice of materials, the design of labyrinthine gas-handling networks, and the overall durability of the oxygen production system. The research therefore implicitly emphasizes not only the energy cost per kilogram of oxygen but also the broader engineering costs of turning a laboratory pathway into a robust planetary-scale operation.

In sum, the Moon’s ilmenite story is one of potential opportunity coupled with technical and logistical complexity. The viability of ilmenite-based oxygen production will hinge on the practical verification of deposit concentrations, the demonstration of scalable separation and purification methods, and the ultimate demonstration that a lunar refinery can operate reliably within the Moon’s harsh environment. All of these elements intersect with energy costs, mission planning, and the broader architecture of a sustained human presence on or near the Moon.

Energy, time, and the scale-up challenge: what it would take to fuel a fleet

The energy budget is only part of the picture. The scale-up question—how a lunar oxygen production system would support repeated launches of heavy-lift vehicles—requires translating kilowatt-hours per kilogram into production throughput, given the constraints of power availability, storage, and mission tempo. The study’s calculations, anchored in conservative estimates, show the following:

• The energy intensity per kilogram is dominated by the high-temperature hydrogen reaction and the downstream water-splitting step. The majority of energy is expended in producing water from ilmenite, with roughly half of the total energy directed at this hydration reaction, and about 38 percent devoted to splitting water into oxygen and hydrogen. The remaining energy accounts for liquefaction and handling losses, with liquefaction being a relatively small share.

• The total energy-to-output ratio yields about 24 kilowatt-hours per kilogram of liquid oxygen produced, subject to the assumed reaction efficiencies and the extent of ilmenite purification. This figure is sensitive to process optimization, heat recuperation, and the overall system design. If improvements can be achieved in heat management, separation efficiency, or catalytic performance, the energy-per-kilogram number could be reduced, enabling higher throughputs per unit of installed power.

• In practical terms, the existing solar-power analogy suggests that a 100-kilowatt solar array on or near the Moon would produce roughly four kilograms of LOX per hour under baseline assumptions. This rate implies that achieving a tonne of LOX would take about ten days of continuous operation. It also implies that producing oxygen for a fully fueled Starship, which carries more than 500 tonnes of LOX, would require a dramatic scale-up in both power and processing infrastructure, or a long series of continuous production cycles across multiple facilities or long operating campaigns.

• The diurnal cycle on the near side of the Moon further constrains throughput. With lunar daytime lasting about 14 Earth days and nighttime lasting roughly 14 Earth days as well, a near-side facility would effectively operate at about half-capacity during the night. This reality underlines the potential necessity of a continuous power source—such as a compact nuclear reactor designed for lunar operations—to sustain production around the clock, thereby improving the economics of scale.

• The pace of production would be a function of the deposit quality, the capacity and reliability of processing lines, and the efficiency of heat management. A modest improvement in the separation step might deliver outsized gains in overall throughput because reducing contaminants enhances the heat, mass, and energy balance of the high-temperature reactor. The energy cost savings from cleaner feedstock could compound through each cycle, enabling a higher rate of oxygen output for the same power input.

• The comparison with a terrestrial solar farm demonstrates the scale of the engineering challenge. A large solar array in space or on the Moon would require not only an enormous surface area but also substantial power conditioning and energy storage to maintain a steady supply to the high-temperature reactors. The energy costs of heat transfer, heat storage, and thermal management would shape the layout of the production complex, including heat exchangers, insulation, and the thermal isolation of sensitive components.

The broader implications of this energy analysis are twofold. First, the Moon-based oxygen production pathway is not a foregone conclusion of immediate practicality; it is a compelling option that could become viable with targeted engineering advances, disciplined design optimization, and reliable power systems. Second, the choice between solar and nuclear energy is not simply about availability; it is also about the stability of throughput, the reliability of production cycles, and the resilience of the energy supply against lunar environmental hazards and the risk of partial system outages.

The study’s authors note that their analysis is an early step in quantifying lunar-based oxygen production. It is not a final blueprint for a production facility, and it deliberately focuses on one pathway with clear energy implications. The purpose is to establish a baseline from which more detailed engineering studies can depart. As missions to the Moon and beyond proliferate and as the space economy evolves, such energy budgets will be crucial in evaluating cost, risk, and feasibility. The numbers illuminate a path—one that could enable deeper space exploration—but they also illuminate the scope of the engineering and logistical tasks that must be undertaken to realize that path.

Infrastructure, logistics, and the human element

A lunar oxygen production system, even one built around ilmenite, is not a standalone unit. It requires a supportive ecosystem of infrastructure, logistics, and human and robotic oversight to be credible at scale. The infrastructure would include:

• Material handling and mining systems capable of collecting regolith from the surface, transporting it to processing facilities, and delivering concentrated feedstock to the refinery units. The design would emphasize redundancy and resilience in a harsh, dusty, low-gravity environment. Autonomous mining and robotics would be essential to minimize human risk and maximize uptime.

• Separation and purification units designed to isolate ilmenite from the broader regolith. The engineering challenge lies in continuous operation at lunar temperatures and pressures, with a capacity to handle variable feedstock quality and fluctuations in deposit concentration. Efficiency gains in this stage would have a disproportionate impact on energy efficiency, making this a high-priority area for improvement.

• High-temperature reaction chambers capable of sustaining sustained, uniform heating, and robust to the thermal cycling characteristic of the lunar day-night regime. The heat management strategy would require careful design of heat exchangers, insulation, and power distribution; it would also must consider radiation shielding and the harsh lunar environment.

• Hydrogen management systems to sustain the hydrogen participation in the ilmenite reaction, including hydrogen supply, safe handling, recirculation, and venting or capture strategies. Because hydrogen is highly reactive, the system would require strict containment, leak detection, and maintenance protocols.

• Water processing units to capture, purify, and split the water produced by the hydrogen reaction, plus the infrastructure to recycle hydrogen for reuse in the reaction stage. Electrolyzers or alternative water-splitting technologies would need to be integrated with the rest of the process to optimize energy efficiency and minimize waste.

• Liquefaction and cryogenic storage facilities to hold LOX in liquid form for loading onto spacecraft. Cryogenic insulation, leak management, and safety considerations are critical for maintaining the oxygen inventory and preventing hazardous incidents.

• Power generation and distribution systems to supply the reactor and all auxiliary equipment. If solar power is chosen, this implies large arrays, energy storage systems, and robust thermal management. If nuclear power is pursued, it implies reactor containment, shielding, waste management, and regulatory compliance.

• Transportation and logistics support between mining sites, processing facilities, storage, and launch pads or other fueling locations. The surface-to-surface movement on the Moon must contend with low gravity and abrasive regolith, which can affect wear on machinery and equipment. The integration of transportation systems with production lines will be a key determinant of overall efficiency and cost.

From a human factors perspective, there is a need to plan for personnel safety, maintenance scheduling, and the possibility of crews living and working near the production facility for extended periods. Even if robots perform the majority of the heavy lifting, human oversight—particularly for system maintenance, calibration, and troubleshooting—will be essential during early operations and for addressing unforeseen contingencies. A hybrid approach that pairs human operators with autonomous systems could provide an effective balance of reliability, safety, and performance in the lunar environment.

The study emphasizes that the presented numbers are part of an early exploratory framework rather than a finished engineering design. But it is also clear that the energy requirements, the process steps, and the spatial considerations collectively set the stage for a disciplined, staged approach to lunar oxygen production. In a staged approach, the initial phase could focus on a modest, pilot-scale facility designed to validate the purification, reaction chemistry, and heat management under actual lunar conditions. The subsequent phases would scale up the production capacity as power systems and logistics mature, with the goal of gradually achieving multi-tonne to multi-hundred-tonne LOX outputs that intersect with mission needs.

In this trajectory, the study’s energy accounting acts as a compass rather than a destination. It helps engineers, policymakers, and space agencies evaluate trade-offs, prioritize R&D investments, and craft robust roadmaps that recognize both the technical realities and the aspirational goals of lunar refueling. It also invites a broader conversation about international collaboration, safety standards, and the governance of a future lunar industrial sector that could service multiple nations and commercial actors pursuing deep-space exploration.

The road ahead: policy, partnerships, and the long arc of exploration

While the technical and energy questions are central, the broader context for lunar oxygen production is shaped by policy decisions, international collaboration, and the evolving space economy. The viability of establishing a lunar fuel depot rests in part on decisions about:

• Investment in lunar infrastructure: Public agencies and private companies will need to collaborate on funding for autonomous mining hardware, power systems, and cryogenic storage. A staged funding plan that aligns with mission milestones would reduce risk and improve the odds of achieving measurable oxygen outputs at each stage.

• Safety and environmental considerations: The creation of large-scale oxygen production on the Moon involves safety protocols to prevent leaks and unintended chemical reactions. The lunar environment presents unique hazards, including volatile regolith dust and extreme temperature swings, which necessitate rigorous testing, verification, and quality assurance for every component of the production chain.

• Intellectual property and knowledge sharing: The engineering challenges in lunar oxygen production will benefit from collaborative research and development across institutions. Sharing findings on mineral processing, high-temperature reactors, and cryogenic storage can accelerate the maturation of practical, deployable technologies while maintaining a competitive and innovative research ecosystem.

• Economic viability and mission planning: The calculus of whether lunar oxygen production makes sense depends on mission cadence and the cost of Earth-to-Moon supply chains versus in-situ resource utilization. If production scales up to levels that meaningfully reduce Earth-derived propellant needs, the economics could shift in favor of lunar refueling as a standard capability for deep-space missions.

• Environmental stewardship and planetary protection: As with any planetary resource development, there is a need to align exploration and exploitation activities with planetary protection principles. The long-term sustainability of lunar operations, including waste management and the potential for contaminant introduction to pristine lunar environments, must be part of strategic planning and governance discussions.

The energy cost per kilogram of LOX, the distribution of ilmenite on the Moon, and the dynamics of power supply all feed into a larger strategic narrative: lunar refueling could become a transformative capability, but it requires substantial, coordinated effort across engineering, operations, safety, policy, and international cooperation. The numbers in the current analysis are a starting point for that conversation, a way to frame the technical questions and guide the next generation of research and development.

Conclusion

The idea of turning the Moon into a fuel depot is not a speculative dream; it is a concrete engineering challenge framed by energy economics, mineralogy, and systems integration. The specific focus on ilmenite as a source of oxygen offers a tangible pathway to quantify one of the most critical inputs for spaceflight: liquid oxygen. The analysis shows that extracting oxygen from ilmenite at meaningful scales would demand about 24 kilowatt-hours per kilogram of LOX, with the largest energy demands concentrated in the high-temperature hydrogen reaction and the subsequent water-splitting step. The results underscore that the real barrier is not only chemistry but also scale, infrastructure, and power.

If lunar oxygen production proves viable, it would require a carefully staged, highly integrated approach that couples mineral processing with high-temperature reactors, hydrogen management, water electrolysis, and cryogenic storage, all powered by a robust and reliable energy system. The near-side mare regions could offer the most practical entry points for initial deployments, but the long-term vision inevitably involves scaling production, refining processing efficiency, and potentially employing nuclear power to achieve continuous, year-round operation.

The road from energy budgets to orbital missions is long and complex. Yet, the study provides a valuable, quantitative anchor for that journey, turning a broad aspiration into a set of concrete engineering questions. As humanity contemplates longer voyages to Mars, the outer planets, and beyond, lunar in-situ resource utilization will likely play a pivotal role. This research does not claim to have solved the entire problem of space fuel logistics, but it delivers a rigorous, data-driven snapshot of what it would take to extract oxygen from lunar minerals at scale, and it lays out a clear path for the next steps—technological, logistical, and strategic—that could push humanity from a Moon-based concept into a practical reality.