The six proposed Metrics for Sustainability offer a framework that moves beyond vague aspirations toward measurable performance. Material circularity captures the proportion of materials that remain in productive use across a lunar settlement, providing a quantitative analogue to recycling rates on Earth but extended to include the recovery of volatiles from waste streams and the repurposing of hardware at end of life. Life-support energy performance reflects the efficiency with which a habitat sustains breathable atmospheres, potable water, and thermal regulation, all of which demand continuous power through the two-week lunar night when solar generation is unavailable. Agricultural output measures the capacity of a settlement to produce food locally, which reduces launch mass from Earth, improves diet freshness for crews, and buffers against supply chain interruption.

Social cohesion as a metric may appear unusual in an engineering context, yet the evidence from isolated, confined, and extreme environments on Earth consistently shows that interpersonal dynamics, governance structures, and habitat design strongly influence mission outcomes. Research into salutogenesis in space emphasises that wellbeing is not merely the absence of illness but the presence of factors that help crews thrive, including a sense of coherence, meaningful work, and environments that support psychological adaptation. The finding that only a small minority of surveyed respondents expressed willingness to live in very small space settlements underscores that perceived habitability and community size matter to real people, and that any long-term lunar presence must be designed with human factors as rigorously as with power systems or landing pads.

Supply chain resilience, the fifth metric, acknowledges that even a mature lunar settlement will remain connected to Earth through the exchange of specialised components, scientific instruments, and personnel. Resilience in this context means the ability to absorb shocks, whether geopolitical conflict disrupts international partnerships, economic downturns curtail budgets, or a launch failure removes a critical logistics node. A settlement that can fabricate more of its own spares through additive manufacturing, maintain buffer stocks of essential consumables, and operate degraded systems safely for extended periods scores higher on this metric than one dependent on just-in-time delivery from Earth.

The final metric, legal and governance frameworks, is perhaps the most consequential and the least technologically deterministic. The Outer Space Treaty of 1967 established foundational principles, including that space is free for exploration and use by all states and that celestial bodies are not subject to national appropriation, but it was written long before the prospect of commercial lunar resource extraction became plausible. Subsequent instruments, national legislation, and multilateral initiatives have begun to address gaps, yet substantial ambiguity remains regarding property rights in extracted resources, standards of environmental protection on the lunar surface, coordination of activities to avoid harmful interference, and mechanisms for dispute resolution. The paper’s argument that the Spacefaring scenario is most desirable partly depends on the existence of agreed norms that allow multiple actors to operate without conflict.

The four scenarios, Red Tape, Run for Resources, Restricted Operations, and Spacefaring, function as a foresight tool that illuminates how different combinations of governance and technical choices lead to divergent futures. In a Run for Resources world, competitive dynamics could produce rapid activity but also duplication, environmental degradation of scientifically valuable sites, and increased risk of accident or confrontation. Restricted Operations, by contrast, might protect the lunar environment through excessive caution while foreclosing the benefits that a sustained presence could deliver, including scientific discovery, economic development, and the demonstration of technologies needed for eventual Mars missions. The Spacefaring scenario emerges as preferable because it couples ambitious activity with cooperative governance and sustainable practice, treating the Moon as a place where humanity learns to live and work off-planet responsibly.

The staged model of lunar presence, moving from robotic reconnaissance through short-termSortie missions to long-term habitation and eventually something akin to a lunar village, provides a useful temporal scaffold for planning sustainability interventions. At the robotic stage, sustainability considerations centre on planetary protection and the avoidance of contamination at sites of scientific interest, such as permanently shadowed regions where water ice records billions of years of solar system history. Short-term missions introduce questions of landing site selection, traffic management, and the cumulative effects of repeated landings on regolith dynamics and the exosphere. Long-term habitation raises the full suite of circular economy challenges, including waste processing, radiation shielding through regolith construction, and the provisioning of agriculture under artificial light.

The lunar night deserves particular emphasis because it dominates the engineering envelope of any permanent presence. Fourteen days of darkness mean that solar power alone cannot sustain life support without substantial storage or complementary generation, and options such as fuel cells, nuclear surface power, and strategically sited solar arrays at peaks of near-eternal light near the poles are all under active investigation. Any sustainability metric on energy performance must therefore account for night survivability, not just daytime efficiency, because a settlement that cannot reliably endure the night cannot claim long-term resilience. The paper’s pragmatic definition of permanence, as continuing operations by successive crews with continuous robotic support where technology cannot yet fully overcome the night, reflects this reality honestly.

In-situ resource utilisation sits at the heart of the technical vision. The lunar poles are believed to host water ice within permanently shadowed craters, a resource that can yield drinking water, breathable oxygen, and, through electrolysis, hydrogen and oxygen propellant. Regolith itself can be sintered or bound into building elements, providing radiation shielding and thermal mass without importing construction material. Oxygen constitutes a large fraction of regolith oxides, and extraction processes ranging from hydrogen reduction to molten regolith electrolysis are being developed at increasing levels of maturity. Extending ISRU toward ISRU-wellbeing, as the paper proposes, is a novel conceptual move: it suggests that local resources should support not only survival but flourishing, informing habitat architecture, lighting design that mimics terrestrial circadian cues, and communal spaces that foster the social cohesion the metrics seek to measure.

The proposal that the metrics could eventually be embedded in legal, governance, and technical agreements between stakeholders mirrors the way terrestrial environmental standards migrate from voluntary frameworks into binding regulation and procurement requirements. A common measurement language would allow agencies, commercial operators, and researchers to benchmark performance, compare approaches, and identify trade-offs transparently. It could also support proportionate regulation, since rules calibrated to measurable sustainability outcomes are less likely to be either ineffective or punitive than rules drafted in the abstract. The recommended research agenda, which prioritises refining the metrics and soliciting feedback from diverse stakeholder groups, recognises that legitimacy depends on participation, and that frameworks imposed without broad consultation are unlikely to endure.

Connections across the three space domains reinforce the argument that lunar sustainability cannot be pursued in isolation. Launch activity on Earth generates emissions and affects communities near spaceports, so reducing launch mass through ISRU indirectly reduces terrestrial impacts. Orbital infrastructure, including stations that act as gateways for lunar missions, must itself be operated sustainably amid growing congestion and debris in Earth orbit, since a collision or debris-generating event could interrupt the logistics chain on which lunar operations depend. Conversely, technologies matured for the Moon, such as closed-loop life support, advanced recycling, and autonomous construction, have clear applications in orbital habitats and eventually in Mars missions, making lunar sustainability a proving ground for broader spacefaring capability.

Historical context strengthens the case for proactive rather than reactive governance. On Earth, many environmental harms were addressed only after damage became evident and costly, whereas the Planetary Boundaries framework exemplifies an attempt to define safe operating limits in advance. The Moon offers a rare opportunity to apply that lesson preemptively, before large-scale activity begins, because key decisions about landing sites, resource extraction methods, and heritage protection for sites like the Apollo landing areas are still being made. Whether future generations will judge humanity’s return to the Moon as sustainable will depend substantially on choices made in the present decade, and the framework of a Lunar Circular Economy with measurable metrics provides a concrete starting point for making those choices deliberately rather than by default.

Subject of Research: Developing a sustainable human lunar presence using space resources

Article Title: Developing a sustainable human lunar presence using space resources

Article References: Cernev, T., de Zwart, M., & Hessel, V. (2026). Developing a sustainable human lunar presence using space resources. Space and Planetary Resources, 2(1), Article 8. https://doi.org/10.1007/s44461-026-00014-x

Image Credits: AI Generated

DOI: 10.1007/s44461-026-00014-x

Keywords: Developing, sustainable, human, lunar, presence, space, resources, scientific research

The barren regolith that blankets both the Moon and Mars presents formidable challenges for plant growth. This layer of dusty, rocky material lacks the essential nutrients and organic content required to support vegetation, rendering it inhospitable to conventional farming methods. In a pioneering approach spearheaded by Harrison Coker and his colleagues, researchers have begun to examine how organic waste, notably recycled sewage effluent, can chemically and physically interact with simulated lunar and Martian regolith to create soil-like conditions suitable for plant cultivation.

Central to this investigation is a bioregenerative life support system (BLiSS) being developed at NASA’s Kennedy Space Center. BLiSS employs an intricate assembly of bioreactors and filtration technologies that treat synthetic sewage, generating a nutrient-dense effluent rich in elements vital for plant nutrition. This effluent was combined with simulant materials designed to mimic the mineralogical properties of lunar and Martian regolith in controlled laboratory conditions, allowing scientists to observe the weathering processes and nutrient release mechanisms that occur when these materials interact.

The experimental protocol involved subjecting mixtures of the BLiSS effluent with the regolith simulants to mechanical agitation over a 24-hour period. This weathering process was intended to replicate, on an accelerated timescale, the natural chemical interactions that would help convert mineral particles into bioavailable nutrient sources. Analytical observations revealed that the treatments triggered the release of critical elements such as sulfur, calcium, magnesium, and various metals vital for plant metabolic functions. These findings underscore the potential to harness in-situ resources and waste recycling for creating fertile extraterrestrial soils.

Microscopic inspection of the weathered simulants provided additional insights into the physical transformations occurring within the regolith analogs. In the lunar simulant, fine pits and etchings appeared on the mineral surfaces, indicative of chemical dissolution and surface alteration. Similarly, the Martian simulant exhibited a surprising development of nanoparticle coatings, which appeared to reduce the abrasive and sharp nature of the raw regolith particles. These alterations signify important steps toward converting sterile, rocky material into a medium more conducive to root penetration and microbial colonization—both essential for healthy plant growth.

Despite these encouraging laboratory results, it is important to acknowledge the differences between simulants and actual extraterrestrial regolith. While simulants approximate key chemical and physical features, genuine lunar and Martian soils contain unique mineralogy, surface chemistry, and potential toxic components such as perchlorates on Mars, which were not fully replicated. As such, further research is essential to confirm the efficacy of these waste-based soil amendments under realistic extraterrestrial conditions and to devise strategies to mitigate potential hazards.

The promise of this research extends beyond soil creation. By integrating organic waste recycling with in-situ resource utilization, future space habitats could achieve greater self-sufficiency, reducing the reliance on Earth-supplied provisions. Such closed-loop systems are imperative for long-duration missions and permanent settlements where resupply is costly, infrequent, or impossible. Nutrient recovery from waste not only addresses waste management challenges but also creates a renewable nutrient cycle critical for sustainable life support.

This fusion of waste bioprocessing and regolith weathering exemplifies the multidisciplinary nature of space agriculture research, bringing together experts in chemistry, environmental science, astrobiology, and engineering. It also illustrates how lessons from terrestrial sustainable agriculture and waste recycling can inform off-world applications. As humanity moves toward establishing permanent outposts on the Moon and Mars, these pioneering studies lay the foundational knowledge for developing agricultural systems that are both viable and resilient.

Moreover, this line of inquiry echoes popular culture’s imaginative scenarios, where resourcefulness and innovation solve existential challenges in alien environments. The inspiration drawn from science fiction narratives of astronauts converting regolith and waste into fertile ground resonates with the actual scientific efforts underway, bridging imagination with empirical exploration. The convergence of creative vision and experimental science enhances the appeal and urgency of such endeavors.

Looking ahead, the researchers underscore the necessity of in-situ experiments with real lunar and Martian soil samples aboard future missions. Validating the laboratory findings in extraterrestrial settings will be critical to address unforeseen variables and interactions unique to those environments. Additionally, integrating plant growth trials with the treated regolith mixtures will provide practical assessments of the nutritive and structural suitability of these novel soils.

The role of funding and institutional support cannot be overstated. This research benefits from NASA’s strategic programs, including the Space Technology Graduate Research Opportunities and the Mars Campaign Office. These investments underscore the agency’s commitment to developing technologies and scientific knowledge that pave the way for deep space exploration and habitation.

In conclusion, transforming the Moon’s and Mars’s lifeless regolith into fertile grounds through innovative waste recycling and bioregenerative technologies represents a pivotal step toward humanity’s off-world agricultural ambitions. By elucidating the chemical and physical interactions between organic effluents and extraterrestrial soil analogs, this research contributes essential insights to the complex challenge of sustaining human life beyond our home planet.

Subject of Research: The interaction and weathering of lunar and Martian regolith simulants with bioregenerative life support system effluent to develop nutrient-rich growth media for extraterrestrial agriculture.

Article Title: “Lunar and Martian Regolith Simulants Desorb and Weather after Exposure to Bioregenerative Life Support System Effluent”

News Publication Date: 7-Jan-2026

Web References: http://dx.doi.org/10.1021/acsearthspacechem.5c00267

Keywords
Physical sciences, Chemistry, Space sciences