A vision for industry on the Moon

Credits: Michael Nayak / Air University Press

Air University Press, the academic publisher of the U.S. Air Force, this last July published the The Commercial Lunar Economy Field Guide: A Vision for Industry on the Moon in the Next Decade, edited by Michael Nayak. The document presents a revolutionary blueprint for the transformation of the Moon from a scientific curiosity into a vibrant, self-sustaining industrial marketplace in the 2030s. Central to this vision is DARPA’s 10-Year Lunar Architecture (LunA-10) initiative, which seeks to establish integrated, interoperable infrastructure that lowers the barrier to entry for all lunar users. This may help with execution of the Trump Administration’s recent Executive Order (EO) which aims to establish a space policy “… that will extend the reach of human discovery, secure the Nation’s vital economic and security interests, unleash commercial development, and lay the foundation for a new space age”. The Field Guide and the EO are not perfectly aligned but the former provides an architectural blueprint to implement the strategic mandate prescribed by the latter. The EO provides the authority and deadlines (e.g., returning to the Moon by 2028), while the Field Guide provides the technical and economic pathways (LunA-10) to achieve those goals in a manner that will add value for taxpayers. While diving into the specifics of the Field Guide, along the way I’ll highlight how it will help implement the EO.

A Strategic Vision Beyond Unsustainable Symbolism

For decades, lunar exploration has followed a “Flags and Footprints” paradigm—symbolic, government-funded missions that are entirely self-reliant, bringing every gram of power, water, and data storage from Earth. The Field Guide argues that this approach, while scientifically valuable and a display of national pride, is economically unsustainable at the current “million-dollar-per-kilogram” cost of delivery. This is in alignment with the EO which calls for enhancing cost-effectiveness of exploration architectures while establishing initial elements of a permanent lunar outpost by 2030 to ensure a sustained American presence on the Moon, which will lay the groundwork for the exploration of Mars.

The Role of LunA-10

LunA-10 serves as a catalyst to seed the foundational nodes of a future economy on the Moon and in cislunar space. Similar to how DARPA fostered development of the internet and GPS, LunA-10 identifies “scalable nodes” where government investment can accelerate commercial capability. The goal is to move toward a model where NASA and commercial industry can purchase utilities—like power and data—as services, rather than owning the hardware.

Four Economic Ages of the Moon

The Field Guide identifies four distinct stages of development for the lunar economy:

  1. The Exploration Age (2025–2030): Characterized by one-of-a-kind, government-backed missions. Infrastructure is limited, confined to individual landers which are non-extendable.
  2. The Foundational Age: An era of “trail-building” where lunar surface transportation infrastructure is built out and users begin to subscribe to pilot services for power and communications.
  3. The Industrial Age (Target: 2035): Scaling through commoditization. Multi-service hubs provide consolidated thermal and power management, and large-scale manufacturing begins.
  4. The Jet Age: A state of self-sufficiency where In-Situ Resource Utilization (ISRU) will produce services such a propellent depots (lunar hydrogen and oxygen) to enable frequent, low-cost “rocket hop” transport across the lunar surface, servicing permanent settlements and supporting missions headed for deep space.

Pillars of Commercial Lunar Infrastructure

To achieve this vision, the Field Guide details several critical technology sectors that must transition from their experimental phases to full scale industrialization.

Power and Thermal as a Service

In the Exploration Age, not being able to survive the 14-day lunar night is a primary mission-killer. LunA-10 proposes Infrastructure Hubs—massive solar power towers, some taller than the Statue of Liberty, placed at the peaks of eternal light at the Moon’s south pole, a concept that SSP has explored previously. Here is where the Field Guide diverges a bit from the EO, as the latter calls for surface nuclear reactors as a source of reliable power, prioritizing this initiative to be implemented by 2030. The authors of the Lunar Power chapter were operating under the assumption that NASA’s nuclear Fission Surface Power project would not produce hardware soon based on current TRLs, so this source of power was outside the LunA-10 timeline. Of course solar power could be complementary to nuclear power sources. With this approach these hubs would include:

  • Multi-Service Nodes: The power towers do more than collect solar energy; they serve as “Swiss army knives,” on the Moon providing wireless power transmission, communication relays, and hosting Positioning, Navigation, and Timing (PNT) signals.
  • Thermal Microgrids: Just as Earth-based buildings use central HVAC systems, lunar thermal hubs will manage heat for multiple users. They can recycle waste heat from high-energy activities (like mining) to keep nearby robotic assets warm during the lunar night, significantly reducing the mass each mission must carry for thermal survival. This aligns with the EO’s call to deploy nuclear reactors on the Moon which will need to dissipate waste heat that can be put to use.

Logistics: The Lunar Rail Network

Transportation is the lifeblood of any economy. Initially, lunar rovers will be slow and inefficient; moving the cargo of a single heavy lander over long distances could take thousands of hours.

  • The Lunar Railroad: The Field Guide details a plan for a lunar rail network that dramatically increases the speed and volume of cargo transport.
  • Multi-Use Corridors: These rail lines would serve as integrated infrastructure conduits. Alongside the tracks, corridors would include wired power lines, data cables, and pipelines for gas and/or fluid transport. This “bundling” of services reduces the amortized cost for every company operating along the route.

Mining and the Metal Ecosystem

Sustainable settlement requires moving away from Earth-dependency through ISRU.

Conceptual illustration of the Lunar OXygen In-situ Experiment (LOXIE) Production Prototype, part of the Pioneer Astronautics (now part of Voyager Space Holdings) MMOST system. Credits: Mark Berggren / Pioneer Astronautics
  • The Circular Economy: The vision is a “reduce, reuse, recycle” ecosystem where expended rocket stages or other used assets are repurposed for storage and scrap metal is forged into new products on-site.

Orbital Infrastructure: Cislunar Supply Hubs

The economy extends beyond the Moon’s surface into cislunar space.

  • Space Harbors: Orbital aggregation hubs would act as deep-space analogs to terrestrial maritime ports hosting multiple value streams. Services would include rocket gas stations featuring robotic propellent transfer of stored hydrogen, oxygen, and methane; consolidated edge computing centers providing high-performance computing as a service such as autonomous docking calculations or mineral analysis by the hub’s more powerful servers; commodity sharing allowing arriving spacecraft to plug into the harbor to share excess solar power or fuel. By centralizing these activities, a space harbor would lower the mass of payloads a company must launch from Earth, effectively lowering the barrier to entry for any new commercial lunar venture. Arkisys has already begun to develop this type of infrastructure with The Port.
Conceptual illustration of The Port, a modular orbital platform under development by Los Alamitos, California-based Arkisys that will provide services for space assets such as refueling, battery recharging, thruster installation, repair, etc., laying the ground work for large-scale space harbors. Credit: Arkisys
  • Satellite “Retirement”: This model moves away from the “one-and-done” satellite paradigm toward a symbiotic system where older assets are repurposed as sharable resources contributing to the growth of the hub.

Economic and Legal Enablers

The Field Guide emphasizes that technology alone cannot build an economy; a transparent and predictable market framework will be needed.

Property Rights and Law

Under current international law (i.e. the Outer Space Treaty), nations cannot “own” the Moon. However, the Field Guide argues for “Continued Use” and “Allocated” rights, where companies can have exclusive control over the specific resources they extract and the infrastructure they build. The Artemis Accords provide the foundation for global consensus on these principles.

The Commodities Exchange and Board of Trade

To attract serious private capital, the Moon needs market transparency. The Field Guide recommends establishing a Space Commodities Exchange and a Lunar Board of Trade to define the quality and value of lunar resources like oxygen and regolith. This would allow for trading, hedging, and financing similar to terrestrial commodities like gold or oil.

Interoperability via the LOGIC Consortium

A major risk to a nascent economy is vendor lock-in where different companies’ hardware cannot communicate or share power without significant switching costs. To prevent this, DARPA established the Lunar Operating Guidelines for Infrastructure Consortium (LOGIC). LOGIC focuses on creating voluntary consensus standards for docking ports, power connectors, and communication protocols, ensuring the Moon becomes an open platform rather than a fragmented collection of proprietary systems.

Artist’s concept of commercial lunar infrastructure that would benefit from accelerating interoperability standards via LOGIC. Credits: DARPA

The Path to 2035

The Commercial Lunar Economy Field Guide concludes that while the engineering challenges of the Moon are “DARPA-hard,” they are solvable. By 2035, the goal is to reach break-even where the economy becomes self-sustaining and the risk for private investors is sufficiently lowered.

Successfully building this infrastructure will do more than just unlock the Moon; it will provide the operational experience, fuel and infrastructure (via ISRU) necessary for humanity to expand throughout the Solar System and eventually, to the stars. The Moon will no longer be just a destination for flags and footprints, but a key stepping stone on the path to becoming a spacefaring civilization.

Execution of the EO in Alignment with the Field Guide

To implement the Executive Order using the principles of the Field Guide the following actions should be prioritized with the caveat that the deadlines specified in the EO will be challenging to meet using many of the technologies in the Field Guide, given they’re current TRLs. Still, regardless of aspirational timelines that may be pushed out, the actions below will ensure that when commercial lunar development comes together in the 2030s, it will be cost effective and sustainable.

Action 1: Immediate Transition to Lunar Commodity Contracts

  • The Problem: Procurement of traditional government-owned hardware is slow and expensive.
  • Implementation: Within the 180-day window mandated by the EO, NASA and the Dept. of Commerce should issue Multi-Service RFPs. Instead of buying a rover, the government should buy “Kilometers of Cargo Transport” or “Megawatts of Night-time Power” from commercial infrastructure nodes described in the Field Guide.
  • Lead Agency: NASA (Commercial Moon to Mars Program).

Action 2: Deploy the Lunar Rail Pilot Program

  • The Problem: The EO’s 2030 call for a permanent outpost cannot be sustained long term by slow, battery-limited rovers.
  • Implementation: Accelerate the Field Guide’s Lunar Rail concept to connect the 2028 landing site to the 2030 outpost location. This would create an industrial corridor that bundles multiple services, e.g. power, data, and transportation, to reduce the cost of individual missions. Such linear easements along railroads would serve as the logistical spine for moving massive cargo fostering economic development in accordance with the EO.
  • Lead Agency: DARPA (transitioning to Space Force/NASA).

Action 3: Codify the Lunar Board of Trade

  • The Problem: The EO seeks $50B in private investment, but investors need price certainty.
  • Implementation: Use the Field Guide’s framework to establish a Lunar Commodities Exchange. Define the “Lunar Standards” for oxygen and water purity. This allows private companies to “pre-sell” resources they will mine in the near future to finance their current operations.
  • Lead Agency: Department of Commerce (Office of Space Commerce).

Action 4: Integrate “Defense-by-Commerce” in Cislunar Space

  • The Problem: The EO calls for US superiority and threat detection in cislunar space.
  • Implementation: Equip the Field Guide’s Infrastructure Hubs with Space Situational Awareness (SSA) sensors. By hosting defense sensors on commercial power/comms nodes, the U.S. achieves the responsive and adaptive architecture required by the EO at a fraction of the cost of dedicated military satellites.
  • Lead Agency: U.S. Space Force.

Conclusion

The Commercial Lunar Economy Field Guide is a ready-made roadmap for implementation of the Whitehouse’s Executive Order on Ensuring American Space Superiority. By treating the Moon as an industrial zone the administration can meet the prescribed milestones through commercial leverage and ISRU rather than massive new government spending. Execution of the plan should focus on contractual reform—buying services from the infrastructure nodes as defined in the Field Guide. With power, comms and security systems in place, companies like Galactic Resource Utilization (GRU) Space can build hotels on the Moon starting in the early 2030s to house scientists, entrepreneurs and maybe even tourists as described in their white paper.

Artist rendering of GRU Space’s hotel on the Moon. Credit: GRU Space

Novel design of a Mars Cycler

Above – Mars Cycler exploded section. Below – Cruise ship-sized Mars Cycler booster (left) and docking configuration (right). Credits: Offworld Industries Corp.

At the 54th International Conference on Environmental Systems held in Prague, Czechia, this past July, a paper was presented describing an innovative design of a large-scale Mars Cycler. The authors, A. Scott Howe, John Blincow, Theodore W. Hall, and Colin Leonard, make the assumption that a significant planetary migration to Mars will happen in the near future, citing Elon Musk’s often stated goal of establishing a one-million person colony on the Red Planet by 2050. The authors argue that Starship will not be a suitable transportation method for a large, non-professional clientele on what has historically been a six-month journey due to the physiological and psychological health risks of a long-duration mission (not withstanding a recent paper penned by University of Santa Barbara physics undergrad Jack Kingdon proposing two trajectories that reduce transit times to between 90 to 104 days each way).

Instead, they envision a “cruise ship” approach using a large, robotically constructed Mars Cycler that would continuously travel between Earth and Mars. The concept for a Mars Cycler was first conceived by Buzz Aldrin in a 1985 paper, and in recognition of his invention, is often referred to as an Aldrin cycler. This particular cycler design is advantageous because it would use minimal propellant to maintain its trajectory. The concept features a dual-torus structure, with a non-rotating outer torus for docking and a rotating inner torus to provide artificial gravity. The paper lays out in detail the specifications for a minimal-sized version with crew capacity of 52-61 people, and calculates the mass and equipment required for the vessel. The authors estimate that it would take 63 Starship launches (version 3) to deliver the construction materials and propellant to low Earth orbit (LEO). A scaled up larger cruise ship-sized version with a capacity of 1000 occupants would take 428 Starship version 3 launches, which is within the range of engineering possibility and certainly within the launch rate of thousands of Starships Elon Musk envisions as part of his Mars colonization plans.

The Mars Cycler would be assembled using Offworld Industries Corporation’s Sargon System, a family of new construction machines the company claims could build an entire space station in half a year (Blincow is CEO of Offworld Industries Corp). The novel construction technology autonomously assembles preformed hull panels loaded in a magazine, robotically dispensed, formed and welded into large toroidal (or other shaped) space stations ready to be pressurized.

The paper advocates for the cycler to provide artificial gravity to mitigate the deleterious health impacts of microgravity allowing occupants to maintain healthy muscle and bone density throughout the journey. The proposed design decouples an inner artificial gravity centrifuge from an outer non-rotating torus, which offers several operational benefits:

  • Distributed docking ports: The non-rotating outer torus can accommodate multiple visiting vehicles docking at various points around its perimeter.
  • Fixed systems: Solar panels and radiators can be mounted without the need for gimbals or motorized mounts, simplifying the design.
  • Seamless transfer: Crew and cargo can be transferred between visiting vehicles and the cycler without the need for spin-up or spin-down procedures.

The paper identifies several challenges to overcome in order to realize an operational Mars Cycler. The top five include:

  1. Large-scale space construction: The project requires the construction of very large orbital structures. A key challenge is maintaining tolerance control during assembly, ensuring panels fit together precisely and the torus closes properly.
  2. Attitude control and maneuvering: The paper assumes, but does not detail, that maneuvering large quarter-toroids in proximity to each other will be possible without “exotic solutions’. This is a significant challenge because each section would have its own center of mass and orbit, creating strain on connected elements.
  3. Artificial gravity implementation: A number of difficulties are discussed, including economic spin-up/spin-down, docking procedures while the structure is spinning, and performing extra-vehicular activities (EVAs) under rotation. The paper also notes that transferring power, control, information, and liquids between the rotating and non-rotating segments would be challenging.
  4. Mars surface infrastructure: The paper acknowledges that a major challenge is the “big elephant in the room of Mars surface infrastructure”. The entire concept is based on the assumption that the necessary infrastructure, such as propellant production facilities, will be in place on Mars by the time the cycler is ready.
  5. Life Support Systems: Sustaining human crews on a cycler for extended periods (e.g., months-long transits) requires robust life support systems for air, water, food, and waste management. The paper underscores the challenge of maintaining these systems with minimal resupply over multiple cycles.

Assuming these challenges could be solved, this interplanetary cruise ship design of a Mars Cycler is a new approach to deep-space travel, elegant in its simplicity. It offers a potential solution to the challenges of long-duration missions by providing artificial gravity via a rotating inner torus to ensure the health and well-being of future Mars colonists.

In addition to these cyclers providing a mode of safe space transportation, such large artificial gravity space stations could be permanently located in orbit around planets or moons that have surface communities in split life cycle space settlements which SSP covered recently. Such a facility could have duel use as an Earth-normal gravity crèche, providing birthing centers and early child development for families settling in the region. Colonists could choose to split their lives between rearing their young in healthy normal gravity settings until their offspring are young adults, then moving down to live out their lives in lower gravity surface settlements – or they may choose to live permanently in free space.

AI networks for space settlements

Artist rendering of a robotic space farm on Mars controlled by a computer network utilizing artificial intelligence. Credits: Bryan Versteeg / Spacehabs.com

In an article in the National Space Society Space Settlement Journal, Bryce Meyer examines the integration of Artificial Intelligence (AI) into computer networks for space settlements. Meyer, an aerospace engineer, computer scientist and biologist is the founder and CEO of Cyan React, LLC, a startup that designs compact photobioreactors and provides expertise in space agriculture and life support for space habitats.

The paper describes the critical role of AI networks will play in enabling sustainable space settlements whether they be on the Moon, Mars, or in free space. These colonies, envisioned to minimize Earth resupply and achieve self-sustaining commercial operations, will face challenges due to limited human occupants (often under 100) and the absence of specialized expertise. AI systems can provide a solution that will bridge knowledge gaps, manage complex operations, and ensure rapid responses to critical issues, such as life support failures, where human reaction times may be insufficient.

The article categorizes AI into distinct families suited for space applications. Neural networks, good at pattern recognition, could help identify equipment anomalies. Generative AI (GAI), excellent at diagnostics and creative problem-solving, could propose solutions for crop failures in space farms or other equipment failures. Regression models would be leveraged for predictive analytics like forecasting resource needs.

These AI systems require robust integration with settlement infrastructure, using standard protocols like TCP/IP for communication. Training of AI agents involves learning from a pre-settlement knowledge base, periodic updates from Earth, and real-time inputs from sensors monitoring environmental conditions, equipment, and biological systems. Error management will be managed with AI outputs cross-checked by other AIs, rule-based systems, or human oversight to prevent cascading failures in critical systems.

Network architectures are key, with Local Area Networks (LANs) enabling low-latency, high-speed communication for real-time tasks like alarms and life support, while Wide Area Networks (WANs) connect settlements to external systems, such as orbital infrastructure or Earth-based servers . AI placement is strategic, positioned near action points within habitats (e.g., farms, life support systems) to minimize latency and ensure reliability in harsh extraterrestrial environments. Power constraints and radiation hardening are critical considerations for AI hardware.

The article presents a detailed scenario illustrating AI coordination in a mass flow system, as would be required in space farm. For example, crop wilting is detected by sensors, triggering a cascade of AI-driven actions: neural networks diagnose the issue, GAI suggests solutions (e.g., adjusting nutrient levels), and regression models predict outcomes. Human settlers, guided by augmented reality interfaces, validate and implement solutions, ensuring effective collaboration. The scenario underscores the need for AI to operate at multiple scales—individual plants, farm systems, and settlement-wide networks.

Bryce agreed to be interviewed via email on this enabling technology for space settlement. I am very grateful for him taking the time to dive deeper into the topic and for his detailed responses to my questions. Here is our discussion:

SSP: You mentioned that many of these AI systems are already in use in indoor farms and factories. Can you provide some examples of these instances?

BM…Not trying to pump a particular company but here are common examples:
Siemens is one of many companies that make networks of these AI enabled control systems, with control center software now: Siemens Industrial Copilot and SmartTron as well as AIRLOCK(InterLock) Systems.

Water Control: Evonik

There are also many new entry startups in this area, such as AGEYE (see below), and others, many have already tried and failed as businesses. Emerson Process is similar, with many offerings and architectures in Chemical Process Automation and Response. BASF is another with it’s xarvio® Digital Farming Solutions. Monnit makes Internet of Things (IoT) plant sensors and sensor reporting software.

It is a very active business area bridging strict rules based to AI enabled rules based and GAI systems with IoT.

SSP: In your example of an AI farm agent detecting a wilting problem with a tomato plant and coming up with a solution, you acknowledged that there are many ways in which ecosystem failures could a occur in a space farm and these scenarios would have to be anticipated to train the AI systems. Has work already been started on an AI controlled farm fault tree analysis, perhaps by the entities running the indoor farms you mentioned in Item 1?

BM…Absolutely! IoT and AI are used in combination in many indoor farms now, just not all the way to the point as shown in the paper, including the ‘recreational plant’ market and for food plants.  This is in active work now by many companies, AGEYE is one company that does have integrated solutions like the farm part of the paper (or very close to it). With a little development, automated control will combine the systems in #1, with the farm systems, with more advanced and trained systems, IoT sensors and controllers, to get to the settlement level.  It will take a merger of these to get there, but we are very close. Have parts, just need to integrate to get to the vision in the paper.

SSP: Prior to implementation for safe use in a space colony, AI systems would have to be trained on a variety of settlement functions in ground-based analogs. Perdue University’s Resilient ExtraTerrestrial Habitats Institute is doing work in this area as well as the Space Analog for the Moon and Mars at the Biosphere 2 facility in Arizona, and of course MELISSA in the EU. Are you aware of any other teams in academia or government working on this now?

BM…Really miss Ray Wheeler’s et al. NASA Biomass Production Chamber, which was the right size and type, would just need updates.

South Pole research station would work well for testing these systems…in a harsh place, limited human presence.

I know Space Development Network is proposing an inflatable farm to develop this technology too, though it needs funding.

AI control for factories and indoor farming is an active corporate area and they have their own extensive facilities, including near my home in St. Louis with Bayer (formerly Monsanto), though they aren’t focused on the particulars of space, per se, yet.

China also has extensive analog labs, since they do seek to beat the USA to long term Moon and Mars settlement. They occasionally publish.

Many colleges have funded work on vertical and indoor farming, several in my home state including at [University of Missouri-St. Louis] UMSL’s planned Yield Lab.  Technical Schools like Ranken also teach and develop methods for indoor farming that could help development of these AIs. All of these facilities can be used to shake out AI systems too.

SSP: In private industry, a few companies are actively involved in developing space-based agriculture. I’ve covered one such company, Orbital Farms, which leverages Earth’s “Dark Ecosystem”, the food chain based on bacteria that are chemotrophic, i.e. deriving their energy from chemical reactions rather than photosynthesis. An example of these type of organisms are bacteria that live near volcanic sulfur vents at the bottom of the ocean. The energy inputs and material flows of these ecosystems are 100 times more efficient in water and energy use per unit volume when compared to conventional photosynthetic food production. The very same organisms can be engineered to make pharmaceuticals, plastics, and a variety of other useful complex organic compounds. Have you considered this approach to optimize mass flows and utility in space farm ecosystems?

BM…Of course. I have considered bioreactors, both photobioreactors and non-light based systems, for a decade. They are the Swiss Army Knife of mass balancing, though I don’t see them as primary food source except in emergencies unless 3d printing and other methods become far better in the culinary sense. Food is critical for psychology too. As is the need to see green and feel and smell plants and crops. Bioreactors have many profiles and uses on Earth now, and the dark cycle chemosynthetic systems are among these. I don’t see a lack of electrical power a problem, just my 2 cents, due to nuclear reactors or space solar power in long term settlements, so I see gardens and farms. Carbon is the problem in a mass cycle. However, the dark cycle systems would be essential for making biochemicals that are either lacking from farms and algae or needed to control the mass cycling in systems. Since we are minus the huge soil ecosystem on Earth for a long while, and may need time sensitive production, the dark cycle systems would be a must just to control the overall system. I do see those on spacecraft that have limited volume, that provide bulk calorie cycling, along with smaller plant systems.

SSP: In your example in Figure 12 of a small settlement of 10 people where the mass flows are 22kg per day to and from the farm, how big is the farm in cubic meters and what would be grown there to provide enough sustenance and oxygen for the occupants?

BM…Around 1400 square meters, 2400 cubic meters (very pessimistically) assuming a VERY diverse crop mix including a few shrimp, multiple veggies and crops like potatoes or peanuts/soy, and bioreactor array with tanks, and walking areas, with continuous crop production ad infinitem. Sounds big, but that is about the size of two three-story healthy midwestern suburban houses, very roughly. Less diverse crop sets can shrink the farm drastically, to around 25% of the size, but with less dietary diversity.

SSP: With respect to training AI systems to be “space rated”, the first iterations to be implemented off Earth will not be entirely autonomous (as you have shown in your examples) and will have humans in the loop until error rates can be reduced to some tolerable level. With the speed at which AI and robotics are progressing today, while at the same time, settlement of the Moon and Mars seems to be advancing at a snail’s pace, do you see the two technologies converging in the near future so that when permanent colonies are finally established, AI networks will be able to autonomously control most critical functions without human intervention?

BM…I never will fully trust AI for everything, and I don’t think the settlers will either, at a minimum due to cybersecurity. That said, the advances in both systems and software will continue to allow more complex settlements monitored by fewer people. Automation will really will be a core technology in expanding settlements, and starting them. Farms could be growing and operating steady state before the first long term residents arrive, and as a settlement expands, it could add modules and let AI get it started and growing before bolting it onto a smaller settlement. Some things will see robotics as repair agents. The AI technology expansion will allow for more long term optimization as well, and continue to add resiliency to the settlement.

You could see a retirement home or factory on the moon with only a few human workers to keep the settlement running, a few medical technicians that are AI assisted, and robots that fix many things without bothering the staff.

SSP: You have suggested in a previous post on SSP that space farms on Mars could be the bread basket for the outer solar system. Another space farm advocate, retired software engineer Marshall Martin, has proposed a roadmap for their implementation starting with ground based analogs, but progressing mainly to rotating free space settlements, eventually resulting in millions of farms feeding billions of people throughout the solar system. When do you think we’ll see the first prototype closed loop farm implemented in space?

BM…I want farms everywhere, grounded and floating [in free space], because I want to see Trillions of Happy, Smiling Babies everywhere.

I would bet either Artemis, a company, or China fields one in the next 35 years for sure, likely sooner, just to prove the concept. Orbital factories could drive the need as much as a lunar base, just to limit resupply, but a Mars base or space station that is beyond cis lunar space will have to have such a close[d] cycle farm as a must due to limited resupply. So, when depends on if the cost to orbit gets very cheap, and cost to [the] Moon gets cheap. Cheap lift in cislunar space would limit the need to fully recycle, but beyond that distance the case gets much stronger. If it stays expensive to [get to] the Moon, the Moon would drive the need, and the farm gets built sooner.


In his conclusion to the article Meyer holds that AI complexity must align with settlement needs, balancing sophistication with reliability. Interdisciplinary collaboration is essential to refine these systems through scenario-based testing and practical implementation. By empowering minimally trained settlers, AI networks enhance sustainability, safety, and mission success, laying a foundation for long-term human presence in space.

Meyer has his own website where he collates his research and links about closed cycle farming and other space ecology topics. He is also a NSS Space Ambassador.

Resilient ExtraTerrestrial Habitats Institute at Purdue University releases its Impact Report

Artist impression of a lunar habitat designed for resiliency and autonomy. Credit: Resilient ExtraTerrestrial Habitats Institute

The Resilient ExtraTerrestrial Habitats Institute (RETHi) is at the forefront of developing autonomous and resilient habitats essential for space settlement. The NASA-funded organization just released its Impact Report summarizing work completed to date. SSP reported on RETHi back in 2020.

A key driver for RETHi’s imperative of autonomy in these habitats is the increasing communication delays and limited bandwidth that will severely restrict interaction with controllers on Earth as habitats are established further from home. These limitations necessitate new approaches for managing space habitats autonomously, fundamentally shifting the operational philosophy for future missions. Unlike near-Earth operations where Mission Control provides real-time oversight and intervention, the remote and harsh environment of deep space demands that habitats become self-sufficient entities. This means that intelligence, diagnostic capabilities, and decision-making must reside on-board, transforming the paradigm from remote control to local autonomy. This is a critical design constraint that permeates all of RETHi’s research, influencing everything from structural design to life support systems and robotics.

RETHi’s research is organized into three interrelated thrusts, each addressing a critical aspect of a comprehensive framework for self-managing systems:

  • Resilience (Architecture): This thrust focuses on the fundamental design of habitats. It involves choosing design features and tools to maximize resilience, assessing safety controls, and developing a resilience-based design procedure aligned with NASA’s processes. This ensures that resilience is embedded into the very fabric of the habitat from its inception, making it inherently robust.
  • Awareness (Detection + Diagnosis + Decisions): Addressing the need for autonomy in operations, this thrust aims to detect damage and disruptions, diagnose issues, and support decision-making autonomously. This represents a significant departure from traditional human space flight operations, which rely heavily on large Mission Control teams. The goal is to enable the habitat to “understand” its own state and the nature of any anomalies.
  • Robotics (Enable Action): This thrust is dedicated to expanding the capabilities of autonomous systems by increasing the scope of interventions that can be carried out automatically by robots. This is crucial for construction, maintenance, and repair in hazardous environments where human presence might be limited or too risky.

RETHi’s research is supported by three complementary testbeds, each serving a distinct but integrated purpose, forming an efficient iterative design and validation pipeline:

  • HabSim: This is a computational model of core space habitat subsystems. It incorporates damageable and repairable properties, sensors, and agents for anomaly detection and repair. HabSim can simulate various disruption scenarios, including micrometeorite impacts, fires, Moonquakes, and nuclear leakage. It primarily helps users learn to create and maintain resilient habitats by assessing decision strategies and resilience through simulation-based design, which can reduce mission costs and increase crew safety.
  • CDCM (Control-oriented Dynamic Computational Model): This capability provides a specialized language for rapid prototyping of machine-readable models that capture causal relationships in complex systems. This enables automatic diagnostic reasoners and uncertainty quantification, which are crucial for developing intelligent, self-diagnosing systems.
  • HARSH (Human-Centered Autonomous Resilient Space Habitats): This testbed is a cornerstone of RETHi’s research, providing a unique cyber-physical platform for validating the complex interplay of hardware and software in autonomous space habitat systems. As the physical validation layer, HARSH takes the insights, algorithms, and models developed and refined in HabSim and CDCM, and tests them in a hardware-in-the-loop environment to confirm their real-world efficacy.

These three complementary testbeds provide a sophisticated, multi-stage approach to research and development. HabSim allows for broad, rapid computational exploration of scenarios and design strategies, providing initial insights. CDCM provides the formal language and tools for precise diagnostic reasoning and model building. HARSH then serves as the high-fidelity, cyber-physical validation platform, where the most promising concepts from the computational realm are rigorously tested against physical realities. This iterative process—from broad simulation to precise modeling to hardware validation—minimizes risk, optimizes design, and accelerates the development cycle for a mature engineering pipeline of complex, safety-critical systems.

The RETHi Impact Report summarized the status of many of the Institute’s research initiatives. Although all are important, this post will highlight progress in two key areas of interest: The HARSH testbed and the design of a habitat’s Environmental Control and Life Support System (ECLSS).

Purpose and Unique Capabilities of HARSH

HARSH is a cyber-physical testbed designed to investigate advanced systems health management capabilities for complex systems with deep informational dependencies. The facility bridges the gap between digital simulation and physical reality, allowing for a more comprehensive understanding of system behavior.

The platform’s unique strength lies in its ability to trigger realistic disruption scenarios using hardware and test autonomous recovery. This capability distinguishes HARSH from purely computational models by enabling real-world interaction, sensor feedback, and the validation of autonomous responses against actual physical system behavior. While computational models like HabSim and CDCM are invaluable for initial design and rapid prototyping, HARSH serves as the crucial validation bridge from simulation to reality. It is where theoretical models and algorithms are put to the ultimate test against physical realities, including hardware limitations, sensor noise, latency, and real-world environmental interactions. This is an indispensable step for ensuring reliability and eventual flight certification of autonomous systems.

Facilitating Investigation of Advanced Systems Health Management

HARSH’s cyber-physical nature allows for the investigation of advanced systems health management capabilities, which are crucial for maintaining complex space habitats, especially those with deep informational dependencies. This entails a focus on integrated diagnostics, prognostics, and self-healing mechanisms across multiple interconnected subsystems. In a deep space habitat, a failure in one system, such as a power supply, can quickly cascade to others, like the ECLSS or communication networks.

The ability to test autonomous recovery under realistic hardware-induced disruptions is central to HARSH’s role in validating the Awareness (detection, diagnosis, decision) and Robotics (enable action) thrusts in a practical, integrated setting. To attain advanced systems health management capability, a focus that transcends simple fault detection is required. It implies a sophisticated ability to continuously monitor, diagnose, and predict the health of complex, interconnected systems. HARSH’s ability to test deep informational dependencies and autonomous recovery provides a proactive approach to resilience, where the system not only identifies a problem but also takes corrective action to prevent cascading failures and restore functionality, thereby minimizing the need for human intervention and ensuring mission continuity.

Advancing Life Support Systems for Deep Space: RETHi’s ECLSS Research

As we all know, the ECLSS is critical for sustaining human life in the hostile, closed environment of deep space settlements. The life support system provides essential functions such as breathable air revitalization, water recovery, waste management, and thermal control, directly impacting crew health and performance. The extended durations of deep space missions (and eventual evolution to permanent communities) necessitate a highly reliable and resilient ECLSS, capable of operating autonomously and recovering from disruptions without immediate help from Earth, given the significant communication delays and the unlikelihood of the success of rescue operations due to long transit times.

While a habitat’s structural integrity and autonomous systems are vital, the ECLSS provides the breathable air, potable water, and stable thermal environment necessary for human survival. Any significant failure in these systems directly jeopardizes the safety of the habitat’s occupants, making them the ultimate determinant of mission duration and crew survivability. Therefore, the resilience of an ECLSS will directly dictate how long a mission can last and whether the crew can survive unforeseen events, particularly when autonomous recovery is the only option.

Development of High-Fidelity, Physics-Based Simulation Models

RETHi has developed a high-fidelity, physics-based simulation model for an ECLSS, a sophisticated approach that accounts for the underlying physical principles governing the system’s behavior, allowing for a deep and accurate understanding of its performance.

This advanced model is specifically designed to predict interior conditions under nominal and disruptive scenarios. This capability is vital for understanding how the habitat’s internal environment responds to various stresses, from equipment failures to external impacts, and for evaluating the effectiveness of mitigation strategies. This method of modeling can predict interior conditions under nominal and disruptive scenarios, enabling a proactive, rather than reactive, approach to resilience. Instead of waiting for failures to occur and then responding, RETHi is developing tools to anticipate how the ECLSS will behave under various forms of stress. This predictive capability allows designers to identify vulnerabilities, optimize system responses, and develop robust contingency plans before a space habitat is established, significantly enhancing safety, reliability, and the potential for autonomous recovery. It moves beyond simple performance modeling to detailed stress-testing and failure mode analysis in a virtual environment.

Evaluation of ECLSS Resilience Under Nominal and Disruptive Scenarios

The ECLSS simulation model allows for the evaluation of system resilience. This means the model can assess the system’s ability to withstand disturbances, adapt to changing conditions, and recover from various challenges, ensuring continuous life support. By simulating disruptive scenarios, researchers can understand the precise impact of failures, optimize control strategies, and develop autonomous recovery protocols for critical life support functions, minimizing the need for human intervention during emergencies.

Evaluating system resilience under disruptive scenarios goes beyond merely ensuring individual ECLSS components are reliable. It validates that the system has the ability to maintain its critical functions even when components fail or external disturbances occur. This shifts the focus from preventing individual failures to ensuring the overall system can adapt and recover, which is a hallmark of true resilience in complex, high-stakes environments where human intervention may be limited. This holistic view is essential for long-duration deep space missions, where adaptability is paramount.

SSP covered similar research by Curt Holmer in his master degree thesis modelling the stability of an ECLSS back in 2021. That work attempted to capture the complex web of interactions between biological, physical and chemical processes and detecting early warning signs of critical transitions between systems so that appropriate mitigations can be taken before catastrophic failure occurs. RETHi’s approach takes stability modelling to a deeper level, enabling ECLSS designers to understand the complex interdependencies and vulnerabilities of the system to determine proactive countermeasures.

Conclusion: Paving the Way for Future Space Habitats

The Resilient ExtraTerrestrial Habitats Institute at Purdue University is playing an indispensable role in driving the design and development of resilient and autonomous habitats, which are critical for the future of space colonization. The institute’s integrated, multi-faceted approach to autonomous resilience, exemplified by the HARSH cyber-physical testbed and its pioneering ECLSS research, is foundational for achieving long-duration human presence off Earth.

RETHi’s strategic organization into resilience, awareness, and robotics initiatives address the complex challenges of human survival in deep space, where communication delays necessitate on-board intelligence and self-sufficiency. HARSH serves as the crucial validation bridge, transforming theoretical models and algorithms into tested, real-world solutions for autonomous recovery and systems health management. Concurrently, the high-fidelity ECLSS models ensure that the fundamental life support functions remain robust and adaptable under stress, directly impacting crew safety and settlement longevity.

The comprehensive nature of RETHi’s work positions it as a leader in future large-scale, interdisciplinary research initiatives for resilient space habitats. The Institute’s holistic understanding of the complex challenges of space colonization fosters integrated solutions across multiple scientific and engineering domains, supported by robust testing infrastructure. The Institute’s current research findings are a blueprint for effective advanced research and development needed for the next frontier of human expansion into the solar system, emphasizing a paradigm shift towards self-sufficient extraterrestrial settlements.

Interlune attracts customers for Helium-3 mined from the Moon

Conceptual illustration of an excavator gathering lunar regolith, which upon separation and extraction of Helium-3, would transfer the valuable cargo to a spacecraft for shipment back to customers on Earth for industrial applications. Credits: Interlune

Payload reports that Seattle based Interlune, a space resources company, on May 7 inked a deal with its first customer Maybell Quantum to purchase thousands of liters of Helium-3 (He-3) sourced on the Moon. Interlune has developed an innovative excavator that will gather lunar regolith, process it and separate out He-3 for return to Earth. The company plans to launch a prototype of their equipment to the Moon in 2027, establish a pilot production plant by 2029, and deliver thousands of liters of He-3 to Maybell, a cutting edge quantum computing infrastructure company, for annual deliveries through 2035.

On the same day, Interlune entered in to a purchase agreement with the Department of Energy Isotope Program to deliver 3 liters of He-3 no later then 2029. The DOE IP utilizes He-3 primarily for scientific research, neutron detection, and cryogenic applications that support its mission to produce and distribute isotopes for research, medical, industrial, and national security purposes.

What’s the market for He-3? In 2023, the global He-3 market was valued at approximately USD 178.68 million, with projections to reach USD 224.59 million by 2031, growing at a compounded annual growth rate of 2.9% (2024–2031). Currently, He-3 has applications in medical imaging, neutron detection in border security, cryogenics and quantum computing; and of course aneutronic nuclear fusion research. This latter application has been touted for decades as a huge potential market for mining He-3 on the Moon as it is extremely scarce on Earth, with most supplies derived from tritium decay in nuclear weapon stockpiles, mainly in the U.S. and Russia. The going rate for Helium-3 is about $20M per kilogram.

Aneutronic fusion produces minimal neutrons as byproducts. This is advantageous because it reduces radioactive waste, simplifies reactor design, and allows for direct energy conversion (DEC). This method of generating power works by capturing the kinetic energy of the positively charged protons in the plasma, converting it directly into electricity using electromagnetic fields without the need for steam turbines. The most common He-3 fusion reaction is deuterium-Helium-3 (D-He-3), where deuterium (D, a hydrogen isotope) fuses with He-3 to produce a Helium-4 nucleus and a high-energy proton, releasing approximately 18.4 MeV of energy.

The current front runner using this approach is Everett Washington startup Helion Energy targeting commercial power generation by 2028. Their modular generators (roughly the size of a shipping container) are designed to power data centers or industrial facilities at a projected cost of ~1 cent per kWh. Helion signed a Power Purchase Agreement with Microsoft in May 2023 to deliver at least 50 MW of fusion power by 2028. They are also collaborating with Nucor, a North American steel products company, to build a fusion power plant on one of its steel mill sites in the United States.

Helion uses a pulsed non-ignition magneto-inertial fusion system called a Field-Reversed Configuration (FRC). Two FRC plasmoids (doughnut-shaped quasi-stable plasma structures) containing D-He-3 fuel are accelerated toward each other at over 1 million mph using magnetic fields, collide, and are compressed to fusion conditions (>100 million °C). Energy is extracted inductively as the plasma expands via DEC.

Achieving and maintaining 100 million °C will be extremely challenging. Some experts doubt Helion’s 2028 timeline, citing the difficulty of achieving net energy gain (Helion has not yet achieved engineering breakeven). This is why Interlune is focusing on more near term markets such as Maybell’s dilution refrigerators to provide cryogenic cooling for quantum computing customers.

Image of Maybell Big Fridge, a dilution refrigerator that utilizes He-3 to provide cryogenic cooling below 10 millikelvins for quantum computers. Credits: Maybell Quantum

Executing Interlune’s business plan will be difficult as all components in the supply chain provided by commercial partners need to work in concert like a well oiled machine. Launch vehicles will have to transport the excavators to lunar orbit and landers (still in development) need to deliver the equipment to the surface. After the He-3 is processed and stockpiled, a return craft will have to launch it back into space, return it to Earth, and reenter the atmosphere safely to deliver the cargo back home for distribution to customers.

On the bright side, if the company can secure a reliable supply chain for He-3 other potential customers with applications such as fusion propulsion for rapid transit throughout the solar system are gradually progressing toward technology readiness. Princeton Satellite Systems in New Jersey is close to developing a Direct Fusion Drive using their own FRC reactor design. The system is based on over 15 years of research at the Princeton Plasma Physics Laboratory (PPPL)

Conceptual illustration of a rocket utilizing fusion propulsion. Credits: Princeton Satellite Systems

According to the company’s website, once the support infrastructure is in place, “… Interlune will harvest other resources such as industrial metals, rare Earth elements, and water to support a long-term presence on the Moon and a robust in-space economy.”

Update July 10, 2025: Another company competing in this space, Scottsdale, AZ based Lunar Helium-3 Mining, LLC (LH3M) recently secured five patents for their end-to-end process for detection, extraction and refinement of He-3 sourced on the Moon.

Conceptual illustration of potential design of LH3M rovers harvesting He-3 from lunar regolith for refinement and transport back to customers on Earth. Credit: LH3M

Sierra Space and payload integrator Tec-Masters to facilitate test of Honda’s Circulative Renewable Energy System on the ISS

Artist impression of Sierra Space’s Dream Chaser space plane Tenacity en route to the ISS. Credits: Sierra Space.

Honda is teaming up with Sierra Space and Tec-Masters to test their Circulative Renewable Energy System (CRES) designed to use water and sunlight to produce oxygen, hydrogen, and electricity for use on the Moon. The company’s research suggests that CRES could power a lunar colony, providing life support and fuel while recycling water in a closed-loop system from water sourced in situ.

Honda’s CRES is designed to support lunar activities by generating essential resources using sunlight and water extracted from lunar regolith or ice deposits, especially at the Moon’s polar regions. The system employs a high differential pressure water electrolysis process, which breaks down water into high-pressure hydrogen and oxygen. In a lunar colony, oxygen would be used for breathable air as well as stored in fuel cells to produce electricity, while the water byproduct is recycled back into the system, creating a closed-loop cycle. CRES is efficient, lightweight, and low-maintenance, ideal for settlements established in the harsh lunar environment, including extreme temperature fluctuations and low gravity. The system’s ability to operate under these conditions makes it suitable, potentially reducing reliance on Earth resupply and supporting a sustainable lunar presence.

Honda’s CRES is a sophisticated technology developed to support human activities on the Moon by leveraging local resources. It is part of a joint research effort with the Japan Aerospace Exploration Agency (JAXA), an international partner in NASA’s Artemis program, which seeks to establish a sustainable human presence on the Moon.

Circulative renewable energy system Honda is working to develop as part of the infrastructure for humanity’s sustained habitation on the Moon where resources other than sunlight and water are not available. Credits: JAXA / Honda

The core technology of CRES is a high differential pressure water electrolysis system, which electrolyzes water to produce high-pressure hydrogen and oxygen. Its is an evolution of Honda’s Power Creator technology, initially developed for fuel cell vehicles and hydrogen stations here on Earth, reflecting Honda’s broader commitment to carbon neutrality and sustainability.

Key technical specifications and advantages include:

  • Size and Weight: The electrolysis stack measures 420 mm tall and 210 mm wide, with the overall system at 980 mm tall, making it compact and lightweight, suitable for space transport where costs are approximately $700,000 per kilogram (delivered to the lunar surface).
  • Pressure Capability: It can store hydrogen at pressures up to 70 MPa, about 700 times Earth’s atmospheric pressure, enhancing storage efficiency.
  • Low Maintenance: The system requires no mechanical compressor, reducing complexity and maintenance needs in space.
  • Adaptability to Lunar Conditions: Engineered to withstand the Moon’s extreme environment, including temperature variations from 110°C during the day to -170°C at night, 1/6th Earth gravity, and high radiation levels.

Sierra Space, Honda, and Tec-Masters have formed a strategic partnership to test Honda’s high-differential pressure water electrolysis system on the International Space Station (ISS) facilitated be Sierra Space’s Dream Chaser spaceplane. Dream Chaser has a cargo capacity of over 6 tons and can return payloads to Earth at under 1.5g’s on commercial runways, enhancing its flexibility for space missions. The first Dream Chaser, named Tenacity, is currently undergoing final testing at NASA’s Kennedy Space Center for its ISS mission under NASA’s Commercial Resupply Services-2 (CRS-2) contract. The launch is currently planned for no earlier than the third quarter of this year, however, this first payload will not include Honda’s water electrolysis system. It has not been disclosed which upcoming Dream Chaser mission will transport the system to the ISS.

This testing aims to validate the system’s performance in space prior to operations on the Moon. Sierra Space will manage the mission, working with the Center for the Advancement of Science in Space (CASIS) and NASA, while Tec-Masters will handle payload integration, leveraging their extensive ISS experience. Tec-Masters brings decades of experience in ISS payload integration and certification, ensuring that the electrolysis system will meet stringent spaceflight requirements. The primary objectives of the testing will be to validate that the system can produce oxygen, hydrogen, and electricity reliably in space, crucial for future lunar base operations. This collaboration marks a significant step toward realizing Honda’s vision of sustainable energy systems for space exploration and could reduce the cost and complexity of lunar colonization.

In a Lunar Colony, CRES has the potential to enable a self-sustaining human presence on the Moon, given its ability for in situ resource utilization. Key applications include:

Oxygen Production for Life Support: CRES’s water electrolysis process produces oxygen as a primary output, which can be directly used to sustain colonists, reducing the need for oxygen transport from Earth.

Hydrogen as a Fuel Source: CRES can generate hydrogen as a versatile fuel for various lunar activities, including powering rovers, construction equipment, or spacecraft for cis-lunar operations or return missions to Earth. It can also be used in fuel cells to generate additional electricity, enhancing energy flexibility.

Electricity Generation: The electricity produced by CRES through fuel cells can power the colony’s operations, such as lighting, heating, life support systems, communication equipment, and scientific instruments. This is particularly valuable during the lunar night in lower latitudes, when solar panels can’t generate power due to the absence of sunlight for 14 days.

Closed-Loop Water Recycling: One of CRES’s most significant advantages is its closed-loop design, where water is continuously recycled. Water produced as a byproduct of fuel cell operation is returned to the electrolysis system, minimizing water loss. This is crucial for a lunar colony, where water is a scarce and expensive resource to transport from Earth.

The adoption of CRES in a lunar colony could significantly reduce the need for resupply missions from Earth, lowering costs and logistical complexity. By producing essential life support resources, fuel and electricity on-site, CRES could enable a sustainable lunar economy, supporting long-term habitation which could become a hub for further space exploration, such as missions to Mars.

However, challenges remain, particularly around sourcing water for the system. The quantity and accessibility of lunar water are still being researched, with estimates suggesting ice deposits may be small and dispersed, requiring advanced extraction technologies. Water on the Moon is primarily found in the form of ice deposited in permanently shadowed craters by comets and asteroids over billions of years, especially at the lunar poles, with additional water molecules embedded in lunar soil and rocks due to impingement of the solar wind. Recent research confirms that in addition to water ice in the polar regions, hydration has been found in lower latitude sunlit areas, suggesting a variety of viable sources for CRES. Extraction methods could involve heating lunar regolith to release water or mining ice deposits, though the scale and efficiency of these processes remain areas of active study. The energy required for water extraction and the system’s scalability for a large colony also need further investigation.

Honda’s CRES represents a transformative technology for lunar colonization, offering a pathway to self-sufficiency by leveraging local resources. Its testing on the ISS and eventual integration with lunar water harvesting operations position it as a cornerstone for future space settlement, though ongoing research into water availability and system scalability will be critical for its success.

Split life cycle approach to settling the solar system

Left: Artist impression of the inside of Kalpana One, a free space settlement providing artificial gravity. Credits: Bryan Veerseeg / Spacehabs.com; Right: Conceptual illustration of a colony on the surface of Mars. Credits: SpaceX.

Until recently, space settlement advocates have typically split into two camps: those who favor building colonies on the surfaces of the Moon or Mars, and those who prefer constructing O’Neill cylinders in free space, spinning to provide artificial gravity outside of planetary gravity wells. Readers of this blog know I lean toward the latter, mainly because colonies on worlds with gravity lower than Earth’s could pose problems for human physiology, particularly reproduction. Truthfully, we won’t know if humans can reproduce in less than 1g until we conduct long-term mammalian reproduction experiments under those conditions. It would be far cheaper and quicker to perform these experiments in Low Earth Orbit (LEO) rather than waiting for sufficient infrastructure to be established on the Moon or Mars for biological research.

Another approach involves not sending humans into space at all, instead entrusting space colonization to human-level artificial general intelligence (HL-AGI) and conscious machines—a non-biological strategy. With recent advancements in AGI and automation, conscious HL-AGI robots may become feasible in the near future (though the exact timeline—whether decades or longer—remains a matter of debate). This prospect might disappoint many space advocates who view migration beyond Earth as the next phase of natural biological evolution hopefully starting within our lifetimes. Deploying sentient machines would effectively remove humanity from the equation altogether.

If you’ve been following space colonization in the press you’ve most likely heard of the book A City on Mars by Kelly and Matt Weinersmith. I have not purchased the book but I’ve read several reviews and heard the authors interviewed by Dr. David Livingston on The Space Show to get an understanding of the Wienersmith’s overall viewpoint, which is at the very least skeptical, and to some space advocates downright anti-settlement. The book is very pessimistic taking the position that the science and engineering of space settlements for large populations of people is too challenging to be realized in the near future.

Peter Hague, an astrophysicist in the UK, wrote an excellent three part review setting the record straight correcting some of the critical facts that the Wienersmith’s get wrong. But in my opinion the best critique by far was written by Dale Skran, Chief Operating Officer & Senior Vice President of the National Space Society (NSS). In a recent post on the NSS blog, he links to a 90 page Critique of “A City on Mars” and Other Writings Opposing Space Settlement in the Space Settlement Journal where he provides a chapter-by-chapter, section-by-section response to the entire book as well as rebuttals to a few other naysayer publications [“Dark Skies” (2021) by Daniel Deudney; “Why We’ll Never Live in Space” (2023) in Scientific American by Sarah Scholes; “The Case against Space” (1997) by Gary Westfahl].

However, Skran credits the Weinersmiths with an innovative idea he hadn’t encountered before, one that addresses the challenge of human reproduction in low gravity. They suggest establishing orbital spin-gravity birthing centers above surface colonies on the Moon or Mars, where children would be born and raised in an artificial gravity environment—essentially a cosmic crèche. Skran builds on this concept, proposing that the life cycle of Moon or Mars colonists could be divided into phases. The first phase would take place in space, aboard rotating settlements with Earth-normal gravity, where couples would conceive, bear children, and raise them to a level of physical maturity—likely early adulthood—determined by prior research. Afterward, some individuals might opt to relocate to the low-gravity surfaces of these worlds. There, surface settlements would focus on various activities, including operations to extract and process resources for building additional settlements.

Skran elaborated on this split life cycle concept and outlined a roadmap for implementing it to settle low-gravity worlds across the solar system during a presentation at the 2024 International Space Development Conference. He granted me permission to share his vision from that presentation and emphasized that the opinions expressed in his talk were his own and did not reflect an official position or statement from the NSS.

Taking a step back, the presentation summarized research that has been performed to date on mammalian physiology in lower gravity, e.g. studies SSP covered previously on mice by JAXA aboard the ISS in microgravity and in the Kibo centrifuge at 1/6g Moon levels. The bottom line is that studies show some level of gravity less then 1g (artificial or otherwise) may be beneficial to a certain degree but microgravity is a horrible show stopper and much more research is needed in lower gravity on the entire reproduction process, from conception through gestation, birth and early organism development to adulthood. The question of reproduction in less then 1g is the elephant in the space station living room. In my presentation at ISDC last year, I took the position that the artificial gravity prescription for reproduction could impact the long term strategy for where to establish biologically self-sustaining space settlements leading to a fork in the road: a choice between O’Neill’s vision of free space rotating settlements vs. lower gravity surface colonies (because outside of the Earth all other solar system worlds where it is practical to establish surface settlements have less then 1g – e.g. the Moon, Mars, Asteroids and the moons of the outer planets – I exclude cloud settlements in Venus’s atmosphere as not realistic). I’ve been swayed by Skran’s proposal and have come to the realization that we don’t need to be faced with a choice between surface settlements or free space artificial gravity habitats – we can and should do both with this split life cycle approach.

How would Skran’s plan for settling the solar system work? He suggests we start small with rotating space settlements in LEO like Kalpana Two, an approach first conceived by Al Globus and popularized in his book coauthored by Tom Marotta The High Frontier: an Easier Way. Locating the habitats in LEO leverages the Earth’s protective magnetic field, shielding the occupants from radiation caused by solar particle events. This significantly reduces their mass and therefore costs because heavy radiation shielding does not need to be launched into orbit. In addition, the smaller size simplifies construction and enables an incremental approach. Kasper Kubica came up with a real estate marketing plan for Kalpana in his Spacelife Direct scenario.

Skran promoted a different design which won the Grand Prize of the NSS O’Neill Space Settlement Contest, Project Nova 2. The novel space station, conceived by a team of high school students at Tudor Vianu National High School of Computer Science, Bucharest Romania, slightly resembles Space Station V from the film 2001: A Space Odyssey. Many other designs are possible.

Project Nova 2 rotating space settlement, one possible design of a rotating space settlement initially built in LEO then moved out to the Moon and beyond. Credit: Tudor Vianu National High School Research Centre Team / NSS O’Neill Space Settlement Contest 2024 Grand Prize Winner

But to get there from here, we have to start even smaller and begin to understand the physics of spin gravity in space. To get things rolling Kasper Kupica has priced out Platform 0, a $16M minimum viable product artificial gravity facility that could be an early starting point for basic research.

Conceptual illustration of Platform 0, a habitable artificial gravity minimum viable product. Credits: Platform 0 – Kasper Kubica / Earth image – Inspiration4

These designs for space habitats will evolve from efforts already underway by private space station companies like Vast, Above, Axiom Space, Blue Origin (with partner Sierra Space) and others. Vast, which has for years had AG space stations on its product roadmap, recently revealed plans to use its orbital space station Haven-1 to be launched in 2026 to study 1/6g Moon level AG in a few years, albeit without crew. And of course let’s not forget last month’s post which featured near term tests proposed by Joe Carroll that could be carried out now using a SpaceX Falcon 9 as an orbital laboratory where researchers could study human adaptation to AG.

Illustration depicting a SpaceX Crew Dragon spacecraft tethered to a Falcon 9 second stage which could be spun up (in direction of down arrow) to test centrifugal force artificial gravity. Credit: Joe Carroll

Back the plan – once the rotating space habitat technology has been proven in LEO, a second and third settlement would be built near the Moon where lunar materials can be utilized to add radiation shielding needed for deep space. The first of these facilities becomes a factory to build more settlements. The second one becomes a cycler, the brilliant idea invented by Buzz Aldrin, initially cycling back and forth in the Earth Moon system providing transportation in the burgeoning cislunar economy just around the corner. The next step would be to fabricate three more copies of the final design. Two would be designated as cyclers between the Earth and Mars. Building at least two makes sense to establish an interplanetary railroad that provides transportation back and forth on a more frequent basis then just building one unit.

Here’s the crown jewel: the third settlement will remain in orbit around Mars as an Earth normal gravity crèche, providing birthing centers and early child development for families settling in the region. Colonists can choose to split their lives between rearing their young in healthy 1g habitats until their offspring are young adults then moving down to live out their lives in settlements on the surface of Mars – or they may choose to live permanently in free space.

This approach enhances the likelihood that settlements on the Moon or Mars will succeed. The presence of an orbiting crèche significantly reduces the risks associated with establishing surface communities by providing an orbital station that can support ground settlements and offer a 1g safe haven to where colonists can retreat if something goes wrong. This alleviates the pressure on initial small crews on the surface, meaning they wouldn’t have to rely solely on themselves to ensure their survival. Finally, an incremental strategy, involving a series of gradual steps with technology readiness proven at each stage through increasingly larger iterations of orbital settlements, offers a greater chance of success.

The final step in this vision for humanity to become a truly spacefaring civilization is to rinse and repeat, i.e. cookie cutter duplication and dispersal of these space stations far and wide to the many worlds beyond Mars with abundant resources and settlement potential. There’s no need to choose between strategies focused solely on surface communities versus spin-gravity colonies in free space. We can pursue both, as they will complement each other, providing families with split life cycle settlement options to have and raise healthy children while tapping the vast resources of the solar system.

Images of resource rich lower gravity worlds beyond Mars with potential for split life cycle settlement (not to scale). Top: the asteroid Ceres. Middle: Jupiter’s Moons, from left to right, Io, Europa, Ganymede, and Callisto. Bottom left: Saturn’s moon Titan. Bottom right: Neptune’s moon Triton. Credits: NASA.

A potpourri of artificial gravity topics

Conceptual illustration of three stages in the construction of an Artificial Gravity Orbital Station (AGOS), envisioned to be a potential replacement for the International Space Station. Credits: Werner Grandl and Clemens Böck

In this month’s post we explore a few concepts and challenges related to artificial gravity (AG) that when explored and understood will enable human’s to live healthy lives and thrive in space. First up, Austria-based architect and civil engineer Werner Grandl, a researcher of space stations and space colonies, and mechanical engineer Clemens Böck describe their concept for the evolving construction of a spinning Artificial Gravity Orbital Station (AGOS) in this Research Gate working paper. AGOS is envisioned as a potential successor to the International Space Station (ISS).

The primary aim of AGOS is to mitigate the adverse health effects of microgravity on humans by providing AG. This includes preventing bone density loss, muscle atrophy, and other physiological issues associated with long-duration spaceflight (more on this later). The station would also serve as a platform for scientific research under varying gravity conditions, potentially including zero-gravity, Mars-like gravity (0.38 g), and Earth-like gravity.

AGOS is proposed as a modular, rotating space station with an initial stage composed of four living modules for a crew of 24 and four zero-gravity central modules. The station is designed to be 78 meters in length, span 102 meters, have a rotation radius of 40 meters and rotate at 4.2 rpm to provide approximately 0.9 g of AG for comfortable living conditions. A non-rotating central hub would carry solar panels providing power as well as docking modules, connecting tubes, and a structural framework to maintain stability. The next stage would double the living quarter modules to eight for 48 occupants. The final configuration would finish out the station with 32 modules for 180 inhabitants.

While the ISS operates in microgravity, which is ideal for certain types of research, AGOS would provide a dual environment where both microgravity and AG conditions can be studied. This dual capability could enhance research in life sciences, materials research, and space technology development.

There are difficulties associated with the concept though, which will have to be resolved. The paper acknowledges that the engineering complexities of maintaining a rotating structure in space, ensuring stability, and dealing with the dynamics of spin gravity on the human body, especially disorientation caused by Coriolis forces, will be quite challenging to overcome.

Still, the future benefits made possible by AGOS will make overcoming these challenges worth the effort. When realized, AGOS would help enable more ambitious space exploration goals, including using the facility for human missions to Mars, where AG may be necessary and beneficial for long-term crew health during transit. It also could open avenues for commercial space ventures in Low Earth Orbit (LEO), including tourism and manufacturing under partial gravity conditions. Ultimately, AGOS could be a significant leap in space station design, enhancing both the scientific output and the prospects for human health in space for extended periods.

In a recent update on their concept penned by Grandl in ResearchOutreach, along with collaborator Adriano V. Autino, CEO of Space Renaissance International, they extend the possibility of constructing self-sustaining colonies in space via utilization of lunar and asteroid materials. Asteroids, in particular, could be hollowed out to serve as natural shields against cosmic radiation and micrometeoroids while mining for resources like metals and water.

Grandl describes a feasible design where a mined-out asteroid provides radiation shielding for a rotating toroidal habitat built inside the body for a population of 2000 people. Rotationally driven by magnetic levitation and natural lighting provided by reflected sunlight, the facility would mimic Earth gravity and environmental conditions for healthy living. This colony could sustainably support human life with integrated systems for air, water, food, and waste management.

Artistic rendition and cross sectional layout of an asteroid habitat for 2,000 colonists with a rotating torus driven by magnetic levitation while sunlight is reflected into the enclosure along the central axis illuminating the living space via a mirror cone. Credits: Werner Grandl

This approach would only work for larger solid body asteroids which are fewer in abundance and tend to be further away from Earth in the main asteroid belt. Smaller “rubble pile” bodies that are loose conglomerations of material like the Near Earth Object (NEO) Bennu recently sampled by the spacecraft OSIRIS-REx, could be utilized in an innovative concept covered a couple of years ago by SSP. The asteroid material is “bagged” with an ultralight carbon nanofiber mesh enclosure creating a cylindrical structure spun to create AG on the inner surface. Physicist and coauthor on this work Adam Frank, mentioned this approach when he recently appeared on the Lex Friedman podcast (timestamp 1:01:57) discussing (among many other space related topics) the search for life in the universe and alien civilizations that may have established space settlements throughout the galaxy and beyond (highly recommended).

A cylindrical, spin gravity space settlement constructed from asteroid rubble like that from the NEO Bennu. The regolith provides radiation shielding contained by a flexible mesh bag made of ultralight and high-strength carbon nanofibers beneath the solar panels. The structure is spun up to provide artificial gravity for people living on the inner surface. Credits: Michael Osadciw / University of Rochester

SSP has covered a scenario conceived by Dr. Jim Logan similar to Grandl’s but going big using several O’Neill Island One rotating colonies strung end-to-end in a tunnel drilled through the Martian moon Deimos.

Left: Artist impression of an Island One space settlement. Credits: Rick Guidice / NASA. Right: To scale depiction of 11 Island One space settlements strung end-to-end in a cored out tunnel through Deimos providing sea level radiation protection and Earth normal artificial gravity. Credit: Jim Logan

The authors see the creation of these permanent spin gravity settlements in space as the next step in human evolution. This vision, once considered science fiction, is grounded in realistic engineering and scientific principals.

Back to the near future, Joe Carroll addresses two topics pertinent to how AG might help mitigate deterioration of human health in space in a couple of articles in the December 9, 2024 issue of the Space Review. In the first piece, Carroll poses the provocative question “What do we need astronauts for?”, and argues that robotic spacecraft have surpassed human astronauts in space exploration due to their ability to travel farther, endure harsher conditions, and deliver more data over longer periods at lower costs. This advantage will become even greater as robotic technology and AI progress in the near future.

As an aside, for the foreseeable future there will be a debate over humans vs. machines in space. Regardless of concerns related to risks to safety, costs, and physical limitations, humans will still have the edge over robots for a while when it comes to adaptability/problem solving, complex task execution, spontaneous scientific decisions and public inspiration. A collaborative approach, leveraging the strengths of both humans and robots to achieve more efficient and effective outcomes may be better for space development in the near term.

That being said, Carroll suggests that human spaceflight activities should be focused on assessing the viability of settlements off Earth, particularly by studying human health in lunar and Martian gravity. He emphasizes the lack of data on long-term health effects in low-gravity environments and proposes the use of AG systems in LEO to simulate lunar and Martian gravity for research purposes. Carroll concludes that understanding human health in low-gravity environments is crucial for future space settlements and that humans will play a vital role in this research.

This leads into his second article which provides suggestions on how to quickly test AG in LEO. He suggests launching and deploying a long, duel dumbbell variable gravity station composed of a Crew Dragon capsule tethered to a Falcon 9 second stage that rotates to produce AG. Providing lunar gravity at one end and Martian gravity at the other, the facility would provide an on orbital laboratory where researchers could study human adaptation to these conditions. Such tests would be more cost-effective and less risky than conducting experiments directly on the Moon or Mars.

Illustration depicting a SpaceX Crew Dragon spacecraft tethered to a Falcon 9 second stage which could be spun up (in direction of down arrow) to test centrifugal force artificial gravity. Credit: Joe Carroll

But there are challenges associated with determining appropriate spin rates. This is vital as they influence the station’s radius and cost. Previous studies using vertical-axis rotating rooms on Earth have shown that higher spin rates can cause discomfort, including nausea and headaches. However, these ground-based tests may not accurately represent the sensory effects experienced in space-based AG facilities, where the spin axis is perpendicular to the direction of gravity.

This approach, on which Joe graced the pages of SSP previously, could help determine whether human settlements on the Moon or Mars are feasible and sustainable, especially when it comes to human reproduction and agriculture in lower gravity levels. Incidentally, he contributed to my piece on the impact of the human Gravity Prescription on space settlement presented last May at the International Space Development Conference 2024.

And in case you missed it, Kasper Kupica shared with SSP his Spacelife Direct approach to quickly getting started by selling AG real estate in LEO.

Implementing AG in space habitats could enhance human health and improve various aspects of space station operations (e.g. fluid flow, heat conduction, fire safety) while enabling studies of human physiology under low gravity conditions. Conducting AG tests in LEO is a prudent step toward understanding human health, determining biology related requirements for future lunar or Martian colonies and may ultimately determine the long term strategy for space settlement.

Modeling an ISRU-based energy storage system for sustainable lunar electricity production

Illustration of a Lunar ISRU Energy Storage and Electrical Generation concept (not to scale). The system utilizes three heat transfer fluid circuits. The collection loop in the receiver tube is heated by sunlight from a field of mirrors during the lunar day and circulates to the thermal mass raising its temperature. Upon lunar nightfall, a discharge loop transfers heat from the thermal reservoir to the Stirling engine for electricity production. While the engine is running a thermal regulation loop dissipates heat through the radiator. Credits: system layout by Mario F. Palos and Ricard González-Cinca, modified to add component labels; lunar landscape by Grok 2

One of the difficulties of designing solar power systems for use on the Moon is the challenge of energy storage during the 14 day lunar night at lower latitudes far from the peaks of eternal light at the poles. Such systems would benefit from technology that leverages in situ resource utilization (ISRU) for this critical function rather then expensively transporting batteries from Earth. It would be ideal to model these systems prior to use via computer simulations to optimize the design before bending metal. In the journal Advances in Space Research, Spanish physicists Mario F. Palos and Ricard González-Cinca explore this approach in a paper that examines an ISRU-based system for energy storage and electricity generation.

The architecture of the proposed system, dubbed Lunar ISRU Energy Storage and Electrical Generation (LIESEG), collects solar energy during the lunar day via a mirror field to concentrate sunlight on a receiving pipe containing a heat transfer fluid (e.g. molten sodium). The heated fluid flows to a thermal mass raising the temperature of the energy reservoir. The resultant stored thermal energy from the reservoir is discharged through a second fluid loop used to drive a Stirling engine for electricity production during both day and night. A third heat rejection loop thermally regulates the system by transferring heat from the cold side of the heat engine to the radiator. This modular design balances efficiency and durability under extreme lunar conditions.

The ISRU implementation angle of the study emphasizes the use of lunar regolith and other local materials to minimize reliance on Earth-based supplies. This not only reduces launch costs but also aligns with long-term sustainability goals for lunar habitats.

To analyze the LIESEG system performance, simulations were carried out using EcosimPro software, a tool used by the European Space Agency in multiple aerospace applications, to assess power output, efficiency, and scalability. A comprehensive theoretical model based on the thermodynamics of the subsystems under lunar conditions was developed to analyze the energy flow and efficiency of the system. The study evaluated the specific power performance (power output divided by launch mass) of the system, highlighting its potential to be superior to other conventional methods like photovoltaic systems or nuclear reactors in terms of mass efficiency and sustainability. It also discusses the influence of key factors like the thermal conductivity of lunar regolith, the size and orientation of solar collectors, and the efficiency of the Stirling engine.

The authors conducted a detailed trade-off analysis of technologies, considering criteria like transportability, installation complexity, operational reliability, scalability, and lifespan. Solar collection and thermal conversion technologies were highlighted as critical components for achieving operational stability.

The proposed LIESEG system offers a promising approach for sustainable energy production on the Moon, potentially reducing reliance on Earth-launched resources and enabling longer, more autonomous missions. The system’s feasibility was demonstrated through computer modeling whose results show LIESEG to be practical for initial lunar missions with lower energy needs, as well as for later advanced bases requiring higher power outputs (up to 100 kWe and beyond). This research shows that a LIESEG system has merit for planning future development of energy infrastructure supporting initial lunar outposts and eventually, permanent settlements on the Moon.

Lunar Outpost Eagle to fly on Starship – blazing a trail for lunar highways

Artist rendering of the Lunar Outpost Eagle Lunar Terrain Vehicle. Credit: Lunar Outpost

Space News recently reported that Colorado-based Lunar Outpost has signed an agreement with SpaceX to use Starship to deliver their lunar rover, known as the Lunar Outpost Eagle, to the Moon. Announced November 21, the contract supports the Artemis program with surface mobility and infrastructure services. The agreement positions Starship as the delivery vehicle for Lunar Outpost’s Lunar Terrain Vehicle (LTV), which is a contender for NASA’s Lunar Terrain Vehicle Services (LTVS) program. The exact terms of the contract, including the launch schedule, were not disclosed in the announcements. Lunar Outpost has assembled a contractor team under the banner “Lunar Dawn” to execute the company’s LTV solution. The collaborative development program includes in industry leaders Leidos, MDA Space, Goodyear, and General Motors.

Rover Design Features

  • Mobility and Functionality: The Lunar Outpost Eagle is designed to support both crewed and autonomous navigation on the lunar surface. It’s built to operate even during the harsh lunar night, exhibiting resilience against the Moon’s extreme temperature changes.
  • Collaborative Development: The Lunar Dawn team brings expertise in spacecraft design, robotics, automotive technology, and tire manufacturing, ensuring a robust and versatile design.
  • Size and Capacity: Described as truck-sized, the Eagle LTV is intended to be a valuable vehicle for lunar operations, capable of transporting heavy cargo to support NASA’s Artemis astronauts and commercial activities.
  • Testing and Refinement: The design has undergone human factors testing at NASA’s Johnson Space Center, with feedback from astronauts being used to refine the vehicle’s usability and functionality.

Future Plans

  • NASA’s LTV Program: Lunar Outpost is one of three companies selected by NASA for the LTV program to develop rovers to support future Artemis missions. The other two companies are Intuitive Machines and Venturi Astrolab. After a preliminary design review (PDR), NASA will select at least one company for further development and demonstration, with the goal of having a rover operational in time for Artemis 5, currently scheduled for 2030.
  • Commercial Operations: Beyond NASA’s usage, the rovers will be available for commercial operations when not in use by the agency, aiming to support a sustainable lunar economy. This includes plans for infrastructure development and scientific exploration.
  • Series A Funding: Lunar Outpost has recently secured a Series A funding round to accelerate the development of the Lunar Outpost Eagle, ensuring that the rover project moves forward regardless of the outcome of NASA’s selection process.
  • Long-Term Vision: The company’s vision extends to enabling a sustainable human presence in space, with plans to leverage robotics and planetary mobility for development of infrastructure to harness space resources.

This partnership with SpaceX and the development of Eagle under the Lunar Dawn program are pivotal steps in advancing both NASA’s lunar exploration goals and commercial activities on the Moon.

Once delivered to the Moon by Starship, the Eagle rover will drive over harsh regolith terrain which, as discovered by Apollo astronauts when driving the Lunar Roving Vehicle, presents several unique challenges due to the Moon’s distinct environmental conditions. First, lunar dust is highly abrasive and can become electrostatically charged sticking to surfaces and mechanisms resulting in wear and degradation of wheels, bearings, and sensors potentially leading to equipment failure. The Moon’s low gravity can make traction difficult. Rovers might slip or skid becoming less stable when accelerating, braking or turning. Terrain variability and nonuniformity on loose powdery dust or sharp, rocky outcrops could cause stability issues.

These problems can be solved by creating roads with robust, smooth surfaces for safe and reliable mobility on the Moon. Initially, the regolith could be leveled by robots with rollers to compact the regolith to make it less likely to be kicked up by rover wheels. Eventually, technology being developed by companies like Ethos Space for infrastructure on the Moon using their robotic system for melting regolith in place for fabricating lunar landing pads, could be used to build smooth, stable roads.

A network of roads could be constructed to transport water and other resources harvested at the poles to where it would be needed in settlements around the Moon extending from high latitudes down to the equatorial regions. As envisioned by the Space Development Network, this system of roads could be created to provide access to a variety of areas to mine valuable resources as well as thoroughfares to popular exploration and tourism sites. The development of the highway system could start at the poles with telerobots, then eventually be expanded to include equatorial areas and would be fabricated autonomously prior to the arrival of large numbers of settlers.

Longer term, a more efficient method of transportation on the Moon could be magnetic levitation (maglev) trains. Research into this technology has already been proposed by NASA which is actively developing a project named “Flexible Levitation on a Track” (FLOAT), which aims to create a maglev railway system on the lunar surface. This system would use magnetic robots levitating over a flexible film track to transport materials, with the potential to move up to 100 tons of material per day. The FLOAT project has advanced to phase two of NASA’s Innovative Advanced Concepts (NIAC) program.

Artist’s rendering of the Flexible Levitation on a Track (FLOAT) maglev lunar railway system to transport materials on the Moon. Credit: Ethan Schaler / Jet Propulsion Laboratory