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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
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TESSARAE for orbital biolabs and more

Conceptual illustration of an orbital biolab constructed using TESSERAE architecture. Credit: Aurelia Institute

At last year’s International Conference on Environmental Systems (ICES), Aurelia Institute Vice President of Engineering Annika Rollock presented a paper on development of an orbital TESSERAE habitat to conduct biotechnology research. TESSERAE (Tessellated Electromagnetic Space Structures for the Exploration of Reconfigurable, Adaptive Environments) covered previously on SSP, was conceived and developed by Ariel Ekblaw, cofounder and CEO of Aurelia as part of her doctoral thesis at MIT. A TED Talk by Ekblaw from last April provides more detail on the concept with footage of prototypes demonstrated in space on the International Space Station (ISS).

The paper “Development of a Flight-Scale TESSERAE Habitat Concept for Biotechnology Research Outpost Applications” by Rollock, Max Pommier, William J. O’Hara, and Ekblaw, presents preliminary findings from a case study on the TESSERAE habitat which aims to bridge traditional space station architectures with future-oriented, adaptive designs. Legacy space habitats, such as the ISS, rely on monolithic hulls or cylindrical modules constrained by launch vehicle fairings, limiting scalability and geometric flexibility. TESSERAE offers a departure from these norms by using flat-packed, tile-based modules that self-assemble in orbit to form a truncated icosahedron. This structure, commonly known as a “buckyball” sharing the same shape as the carbon molecule buckminsterfullerene (C60) named after architect and inventor R. Buckminster Fuller due to its resemblance to his geodesic dome designs, will enable larger volumes and novel configurations when connected together.

The authors provide more detail on the concept referencing a trade study presented at ICES 2023 by the Aurelia Institute, which reviewed historical and contemporary space architecture to identify gaps and opportunities. They underscore the need for habitats that are both innovative and grounded in proven engineering principles. The paper serves as a “dynamic snapshot” of the ongoing TESSERAE case study as of spring 2024, inviting collaboration rather than presenting a finalized design. It envisions a platform based on TESSERAE as a commercial biotechnology research outpost in Low Earth Orbit (LEO), aligning with NASA’s Commercial LEO Destinations (CLD) goals and the burgeoning market for microgravity-enabled research. The paper highlights subsystem analyses for environmental control, thermal management, and power, alongside novel interior layouts informed by user research and terrestrial architecture best practices.

The authors make the case that self-assembling structures like TESSERAE could revolutionize human spaceflight by enabling adaptive environments that support diverse crews, including non-professional astronauts. This is particularly timely as the ISS nears decommissioning in 2031, necessitating new orbital platforms for critical research with increasing involvement by private industry..

The mission overview lays out one possible operational vision for the 2030s: a TESSERAE microgravity platform sustaining human life, scientific inquiry with a biotechnology focus, and ancillary activities in LEO. Designed for a crew of four—two biotechnologists and two career astronauts—it features biotechnology applications, capitalizing on microgravity’s unique properties for protein crystallization and biologic medicines production.

Protein crystal growth in space yields superior quality due to reduced sedimentation and convection, facilitating precise structural data for drug discovery. The paper references applications in treating among other maladies, muscular dystrophy, breast cancer, and periodontal disease, citing decades of ISS-based experiments by pharmaceutical firms. Similarly, biologic medicines—proteins, enzymes, nucleic acids, and antibodies derived from natural sources—benefit from low-gravity acceleration in discovery and preclinical testing. The global biologics market is projected to reach over $700 billion by 2030, underscoring the potential economic upside. Innovations like Redwire’s seed-based crystal manufacturing and Varda’s in-orbit ritonavir production (an HIV antiviral) have demonstrated feasibility, with microgravity enabling bulk-free returns via seeds or small samples.

The concept of operations (ConOps) details a 32-tile assembly (20 hexagons, 12 pentagons, each 2.26 m edge length, 0.46 m thick), launched in a dispenser stacked aboard a SpaceX Falcon 9 launch vehicle. After dispensing out of the payload bay, orbital self-assembly employs electro-permanent magnets for bonding at the tile edges, forming a 493 m³ pressurized volume post-clamping and gasketing. Outfitting prioritizes autonomy: critical systems integrate into the tiles, with secondary elements (e.g., storage, mobility aids) added via robotics or minimal EVAs. After full systems checkout post-assembly, operations include 1–6 month crewed expeditions, cargo resupplies, and uncrewed intervals.

Comparative occupancy analysis positions TESSERAE favorably: at 123 m³ per person, it rivals the ISS (168 m³ for six) and Tiangong (113 m³ for three) emphasizing permanent quarters and lab space for its four-person upper limit, ensuring psychological and functional adequacy. This aligns with NASA’s CLD objectives, fostering commercial viability while accommodating “visiting scientists” alongside professionals.

With respect to interior concepts and design principles, TESSERAE’s non-cylindrical, open-central geometry introduces unique interior challenges and opportunities, diverging from conventional axial modules. The paper explores layouts tailored for diverse crews, drawing on user interviews (astronauts, analogue astronauts, scientists) and literature like Sharma et al.’s Astronaut Ethnography Project and Häuplik-Meusburger’s activity-based approach. Five core design principles and “desirements” guide this strategy: a human-centered approach accounting for bodily navigation and psychosocial needs; contextual affordances leveraging microgravity (e.g., multi-axis movement in open volumes); sensory mediation via lighting, acoustics, and airflow for zoned activities; accessibility with ample, clutter-free stowage; and a balance of permanence (fixed volumes) with flexibility (reconfigurable elements like folding partitions).

These principles inform environmental mediations for biotechnology: labs require vibration isolation and containment for experiments, while communal spaces mitigate isolation via views and biophilic design elements. The paper discusses layouts prioritizing flow, orientation, and adaptability. One configuration features a central “node” for socialization and exercise, ringed by radial spokes: private quarters, labs, hygiene nodes, and utility closets embedded in the shell. This exploits the buckyball’s symmetry for efficient use of space, with tethers and handrails guiding microgravity transit. Labs allocate ~100 m³ total, segmented for crystallization (vibration-dampened gloveboxes) and biologics (flow benches, incubators), in accordance with preliminary user needs.

Diagram (Figure 5 from paper) depicting four internal layout options, with key space dividers and elevation maps depicting the arrangement of functional areas on each external tile. Credits: Annika E. Rollock et al. / Aurelia Institute
Exploded view (Figure 6 from paper) of the Lofted layout option for the TESSERAE habitat. Credits: Annika E. Rollock et al. / Aurelia Institute

Sensory design mitigates monotony: variable LED lighting simulates diurnal cycles, acoustic panels dampen noise, and materiality ( e.g., fabric panels) enhances tactility. Stowage integrates nets and modular racks, addressing chronic ISS issues. Flexibility allows crew reconfiguration via magnetic mounts, supporting mission evolution. Hygiene and galley zones emphasize efficiency, with water-efficient fixtures tied to the Environmental Control and Life Support System (ECLSS). Overall, interiors blend spacecraft rigor with architectural humanism, fostering well-being for non-experts.

The authors provide a subsystem analysis discussing trades for ECLSS, thermal control, and power. ECLSS recommendations draw from ISS heritage leveraging NASA’s Carbon Dioxide Removal and Oxygen Generation Assemblies but adapt to TESSERAE’s modularity: distributed nodes per each individual tile reduce single-point failures, with regenerative loops for water and air.

Thermal management addresses the buckyball’s high surface-area-to-volume ratio, prone to radiative losses. Multi-layer insulation and variable-emittance coatings are proposed, integrated into tiles for passive control, supplemented by active radiators and heat exchangers. Finite element modeling was used to inform stress distribution across the tile seams.

Power generation leverages roll-out solar arrays deployed post-assembly, sized for 20–30 kW demands for the needs of the labs, ECLSS and other power systems. Trades evaluate photovoltaics vs. emerging tech, prioritizing launch mass. Batteries buffer eclipse periods, with guidance navigation integrated with attitude control via control gyroscopes, minimizing propellant use.

These analyses emphasize scalability: TESSERAE’s tiles enable redundant, upgradable subsystems, contrasting with legacy monolithic designs.

The paper identifies a few challenges. For instance, assembly reliability (magnet actuation in vacuum), pressurization integrity at seams, and outfitting logistics. But opportunities abound in biotech such as enabling “fly-your-own-experiment” for scientists, accelerating drug pipelines, and demonstrating adaptive habitats for lunar/Mars precursors. User research highlights psychosocial needs—privacy amid openness, sensory variety against confinement—which will inform iterative designs.

Future work matures hardware testing in microgravity (e.g., parabolic flights), refines trades via modeling, and pursues partnerships for CLD certification. The authors invite input, positioning TESSERAE as a collaborative pivot toward reconfigurable space living.

This case study encapsulates one of TESSERAE’s promises: a self-assembling, biotech-focused habitat merging innovation with pragmatism. By the 2030s, it could sustain crews in 493 m³ of adaptive volume in LEO, tapping into a $700B+ market while advancing human-centered space architecture. Preliminary insights from this work — from ConOps to design of interiors— lay the groundwork for transformative outposts that not only return benefits to human lives on Earth, but are preparing humanity to become a spacefaring species.

While the Aurelia Institute is a nonprofit organization, Ariel Ekblaw cofounded a startup called Rendezvous Robotics which aims to generate revenue building large-scale structures like antenna apertures, space solar power arrays and orbital data centers, all autonomously fabricated in space using TESSARAE. Rendezvous Robotics recently partnered with another startup called Starcloud which plans to fabricate gigawatt-scale orbital AI data centers using Ekblaw’s invention, a potentially huge new market forecasted to be just over the horizon by several tech leaders in the news recently. Blue Origin CEO Jeff Bezos just announced he’ll be leading a new AI company called Project Prometheus and says AI orbital data centers are coming in the next decade or two. Last May former Google chief executive Eric Schmidt acquired Relativity Space to put data centers in orbit. Earlier this month Elon Musk says in not more than 5 years, the lowest cost way to do AI compute, will be in space. And Mach33 Research, an investment research firm focused on the industrialization of space, predicts that orbital compute energy will be cheaper than on Earth by 2030. TESSARAE could be leveraged to assemble these space-based hyperscalers autonomously and quickly while proving out this reconfigurable technology which can be used to build large-scale adaptable habitats and other infrastructure in space for a multitude of applications. As stated on the their website,

“Aurelia is working toward geodesic dome habitats, microgravity concert halls, space cathedrals—the next generation of space architecture that will delight, inspire, and protect humanity for our future in the near, and far, reaches of space.”

Artist illustration of a habitat constructed from TESSARAE modules in Earth orbit. Credit: Aurelia Institute

Finally, in celebration of the 50th anniversary of the 1975 NASA Space Settlements: A Design Study, the Institute announced today they are sponsoring The Aurelia Institute Prize in Design for Space Urbanism. An award of up to $20,000 will granted for concepts of a functioning space station in one of three categories: A space station in LEO or at a Lagrange point; a space habitat in lunar orbit or on the surface of the Moon; or an automated industrial facility (e.g. focused on space mining, energy, biotech, etc.) in one of those locations.

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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.

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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

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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.

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Design considerations for rotating space settlements

Illustration of a cylindrical rotating space settlement in Low Earth Orbit. Credits: Grok 3

A paper by German astrophysicist Rainer Rolffs titled Rotation of Space Habitats published last October has been uploaded to the National Space Society (NSS) Space Settlement Journal. The study aims to quantify how much structural mass is required to support both the artificial gravity and the internal pressures in various designs of a rotating habitat. It expands on previous work the author completed on energy flow in such habitats, integrating considerations of cooling, energy collection (via mirrors and photovoltaics), and the distribution of interior mass.

Habitat Geometry and Design Options
Rolffs analyzes several geometric configurations, including:
– Cylinder: A habitat rotating about its central axis, with design trade-offs between compactness and rotational stability.
– Tube: A cylindrical structure rotating perpendicular to its length, featuring rounded endcaps to ensure uniform gravity.
– Oblate Spheroid: A sphere that is flattened along the rotation axis, offering a different balance between structural mass and interior volume.
– Torus: A ring-like structure where the habitat’s thickness is a fraction of the overall rotational radius.
– Dumbbell and Dumbbell with Tube: Two-sphere configurations connected either by cables or a tube; these shapes offer flexibility in managing rotational radius and gravity distribution, especially at smaller scales.

Scaling and Habitat Sizing
The analysis scales the design by considering a constant interior volume per person, leading to a range of populations from very small (few individuals) to billions. Lower limits on habitat size are determined by constraints such as acceptable rotation rates (to maintain human comfort) and the mass needed for shielding against radiation. Upper limits are set by the challenges of maintaining co-rotation of critical components like mirrors for sunlight collection and the growing demands on structural integrity and cooling systems as size increases.

Gravity Distribution and Structural Considerations
The paper provides detailed methods to compute the gravity distribution inside the habitat by dividing the interior into floors with heights that vary inversely with gravity. Rolffs examines how the structural mass must not only counteract the centrifugal forces (to create artificial gravity) but also support the self-weight of the structure, with different methods for vertical (hanging) versus horizontal (standing) support. A “critical co-rotational radius” is introduced, beyond which certain components (like non-rotating mirrors or photovoltaics) can no longer be kept in co-rotation with the habitat without incurring prohibitive mass penalties.

Trade-Offs in Mass Budget and Optimization
Not surprisingly, shielding against radiation is identified as a dominant mass component for small habitats, while for larger habitats, the structural and cooling masses become more significant. The study shows that there exists an optimum size range—between tens of thousands and tens of millions of cubic meters of interior volume—where the payload (interior mass per person) dominates the overall mass budget, and the design can be optimized for cost and functionality. Rolffs finds that different shapes yield different trade-offs; for example, the dumbbell shape is preferable at smaller sizes due to its flexible rotational radius, whereas spheroidal shapes may offer lower structural mass for very large habitats.

Detailed Derivations and Appendices
The work includes extensive mathematical derivations provided in three appendices:
– Appendix A: Details the geometric parameters and derivations for determining the rotational radius and interior volume for each habitat shape.
– Appendix B: Focuses on the gravity distribution within the habitat, explaining how the artificial gravity varies across different floors and regions.
– Appendix C: Deals with structural integrity, deriving the requirements for supporting both the artificial gravity forces and the habitat’s own self-weight, including considerations for both vertical and horizontal support systems.

Rolffs’ analysis provides design guidelines that are critical for planning future space settlements, especially in the context of reducing launch costs and using in-situ resources (e.g., processed asteroid matter) for construction. He concludes that while very large habitats are theoretically possible (even accommodating populations in the billions), practical constraints related to cooling, light distribution, and structural integrity likely favor habitats in the medium-size range with optimized shapes such as the dumbbell or oblate spheroid.

Overall, Rolffs provides an in-depth exploration of the physical and engineering challenges associated with rotating space habitats, providing both theoretical foundations and practical design criteria that could inform future developments in space settlement engineering, earning the top spot on SSP’s Artificial Gravity Section as of this post.

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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.
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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.

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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
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ESA launches the Second Space Resources Challenge

Conceptual illustration of lunar regolith extraction and beneficiation operations creating feedstock for an oxygen production factory on the Moon. Credits: Grok 2

The European Space Agency (ESA) on October 24 initiated their Second Space Resources Challenge. The Space Resources Challenge is an initiative aimed at stimulating innovation in the field of in-situ resource utilization (ISRU) for lunar and potentially other planetary bodies’ development. Launched in partnership with the Luxembourg Space Agency and their joint European Space Resources Innovation Centre (ESRIC), the competition encourages participants from various backgrounds—including students, startups, and established companies—to develop technologies that can collect, process, and utilize resources on the Moon. The challenge focuses on extracting valuable resources like oxygen for human life support and rocket fuel, as well as metals for construction, from lunar regolith. By fostering a competitive environment, ESA seeks to advance technologies that could reduce the dependency on Earth-supplied materials, thereby making long-term lunar missions more economically viable. The competition not only aims to develop new ISRU technologies but also to build a community of innovators interested in the value of space resources, potentially leading to commercial opportunities in the burgeoning space economy.

Launched on October 24, the second Challenge will focus on extraction and beneficiation of lunar regolith, critical steps in establishing a sustainable human presence on the lunar surface. Teams have until February 20th 2025 to submit proposals. Competition winners can claim €500K for the best performing team and will be awarded a development contract for a feasibility study. A second place prize worth €250K will be awarded to the best team in the category of beneficiation.

The first Challenge, which targeted resource prospecting, took place in 2021 and featured a competition between robotic protypes in ESA’s Lunar Utilisation and Navigation Assembly (LUNA) facility, an advanced research and simulation center designed to support Europe’s efforts in lunar exploration. Located within ESA’s European Space Research and Technology Centre (ESTEC) in the Netherlands, LUNA serves as a testing ground for technologies and systems intended for lunar missions. The facility includes a moon-like environment where various aspects of lunar landing, operations, and human habitation can be simulated.

The Second Resource Challenge will focus on:

  • Extraction: The collection, hauling and handling of lunar regolith. In LUNA this will be modeled using lunar simulant, which mimics the Moon’s soil. The problem to be solved in this area of the challenge involves designing robotic systems that can collect and transport material efficiently in the harsh lunar environment.
  • Beneficiation: a term adapted from the terrestrial mining industry, is the process whereby the economic value of an ore is improved by removing the gangue minerals, resulting in a higher-grade product. In the context of ISRU on the Moon, beneficiation will convert regolith into a suitable feedstock through particle sizing and mineral enrichment, preparing it for the next step in the value chain. On the Moon the next process could be extracting valuable resources like oxygen for life support and rocket fuel, and metals for construction or manufacturing, which will be essential for sustaining a long-term human presence on the Moon.

The technology development program will award the teams with the most innovative robotic systems that exhibit autonomy, durability, efficient handling and processing of regolith in the extreme conditions of vacuum, temperature extremes and dust expected in the lunar environment.

Alignment with Strategic Roadmap:

The Second Space Resources Challenge is a pivotal part of ESA’s Space Resources Challenge strategic roadmap to build out the ISRU Value Chain. The next phase of the program will focus on “Watts on the Moon”, i.e. reliable surface power sources for lunar operations. Subsequent phases will develop ISRU applications including extraction of oxygen and water for life support and rocket fuel, with the goal of sustainable in situ factories in the 2030s providing resource supply chains for settlements and the cislunar economy. Integrated systems downstream in the Value Chain, such as Pioneer Astronautics’ (now part of Voyager Space) Moon to Mars Oxygen and Steel Technology (MMOST) application to produce oxygen and metallic iron/steel from lunar regolith, are already under development.

Space Resources Challenge strategic roadmap depicting gradual progression of ISRU development activities. Challenges are planned to be solicited every three years. Credits: ESA

The Second Space Resources Challenge competition is a critical forward-thinking step in ESA’s plans for space development. By concentrating on the extraction and beneficiation of lunar regolith, ESA is not only preparing for the logistics of long-term lunar habitation but also setting a precedent for how future space missions might operate autonomously and sustainably. This challenge underscores ESA’s commitment to innovation, sustainability, and the strategic use of space resources, paving the way for humanity’s next steps in the settlement of the Moon and other worlds in the Solar System.

Update October 2025: This month the challenge resulted in a field test at the LUNA facility. Eight teams demonstrated robotic systems designed to collect and process lunar regolith. The participating teams hailed from six countries including Canada, Denmark, Germany, Luxembourg, Poland and the United Kingdom. A contract for detailed design development will be awarded by ESA next month to the most promising team, which could see flight hardware for mission to the Moon (timeline dependent on future funding).