Pioneering the growth of space settlements

Conceptual illustration of Station 520, a 320 meter diameter rotating orbital space settlement constructed from Stellamer, a plant-based thermoset mixed with plant fiber fillers extruded via an additive manufacturing system. Credit: Orbital Construction Pioneers

At a presentation at ISDC 2026, Orbital Construction Pioneers (OCP) introduced the First Step Manufacturing System (FSMS): an orbital additive manufacturing system that could potentially produce segments for very large structures (on the order of a few hundred meters long) using a bio-material derived from plants grown and processed in orbit.

Why is this important? Humanity’s long-term expansion into the solar system cannot be sustained by continuous resupply from Earth. The cost, complexity, and sheer mass penalties of launching every kilogram of food, water, oxygen, fuel, structures, and spare parts out of Earth’s gravity well become prohibitive as missions move farther out from low Earth orbit. In situ resource utilization (ISRU) has long been recognized as the only practical path to sustainability.

OCP has developed the FSMS as a promising architectural response to this challenge. FSMS is an orbital fabrication platform whose core innovation is biological additive manufacturing. Hydroponic and aquaponic farms operating inside a rotating space station would generate plant biomass that serves as both binder and filler for Stellamer, a bio-derived thermoset polymer. This material could enable continuous, large-scale additive manufacturing of structural components in an artificial-gravity environment. The system simultaneously produces life-support commodities and specialized mission components, creating a symbiotic industrial-ecological ecosystem.

George Tyson, CEO of OCP, came on The Space Show on July 28th to discuss the company’s plans and progress to date with David Livingston and me, along with several members of The Space Show Advisory Board. Tyson spoke with us from his lab in Colorado City, Texas, on the development of Stellamer and showed samples of the material he’s tested. When asked about the technology readiness level of flight-ready hardware and plans for orbital demonstration flights, Tyson indicated that it was still in the early research stages but as soon as they have optimized the Stellamer formulation and are satisfied with the performance of their prototype printer, the next milestone would be validation of the equipment under microgravity conditions on a parabolic flight platform.

Tyson also made an exclusive media announcement. In partnership with Hawaii-based Exo-Scientific, the companies are forming the Interplanetary Regen Network (IRN), a multi-party consortium focused on the collaborative development of bioregenerative systems, advanced in-space construction techniques, and ISRU technologies to sustain human presence beyond Earth. Exo-Scientific provides integrated solutions in engineered aquatic life systems for closed-cycle cultivation, ISRU management, and the practical application and adaptation of Earth-proven sustainability principles to offworld environments. I asked Tyson if Exo-Scientific would provide the life support systems for OCP’s space stations via their aquaponic ecosystems, but he was under an NDA at this juncture, so could not comment on the question. Exo-Scientific was also a presenter at ISDC2026 on their Coral Wetlab concept. Clearly, the company’s systems could be synergistic and complementary to OCP’s technology and plans.

The IRN is soliciting discussions with potential consortium members, government partners, research institutions, and commercial clients interested in advancing bioregenerative systems, in-space construction, and ISRU capabilities for cislunar, lunar, and Mars applications.

OCP’s long-term plan for full-scale implementation of FSMS is to start with the construction of Station 520 in medium Earth orbit (MEO), a 320-meter-diameter rotating habitat that would generate lunar-level artificial gravity at one revolution per minute. The pressurized volume would be approximately 774,000 cubic meters, sufficient to house extensive farms, processing equipment, habitation quarters, and specialized manufacturing functions such as pharmaceutical production and thin-film fabrication. A large-format 3D printer would sit at the geometric center, capable of producing structural segments up to 50 meters across and 6 meters thick. These segments would clad the station’s primary truss frame and enable the fabrication of additional modules.

OCP envisions construction beginning with the launch of seven Version 3 Starship-sized vehicles (or equivalent) that would deliver the essential components for assembly. These vehicles would contain enough scaffolding for the station skeleton, hydroponics and aquaponics materials, the necessary items for the construction of the 3D printer located at the center, plant processing equipment, food, water, air, tools, and EVA suits used by the construction crew. A repair station for EVA suit and equipment maintenance would also be provided, including a small startup crew’s quarters and work area.

Once the vehicles reach MEO, the scaffolding would be employed to build the station skeleton while incorporating the seven vehicles themselves into the emerging framework. Appropriate items such as propulsion systems, electronics, pumps, and related equipment would be relocated from the vehicles to their permanent placement on the scaffolding. The tanks and cargo areas of the vehicles would then be connected to provide pressurized sections that serve as the initial farms. With these foundational elements in place, the station could be spun up to one-third rotation, allowing the hydroponic and aquaponic systems to be mounted and activated.

As plant material becomes available, the plant processing system would be assembled and activated. This system creates the material—thermoset epoxy and plant fibers—required for use in the printer. Using a mix of the station-produced thermoset and plant material, the outside skin and inside bulkheads would then be printed. As the outside of the station is skinned, additional sections would be enclosed and pressurized to accommodate new hydroponic and aquaponic farms. When the construction of the station is complete, rotation is increased to one rpm, and tenants could then be allowed to move in.

As stated previously, central to this entire sequence is the FSMS 3D printer, which would be integrated into the structure of the station. The printer will utilize materials grown and processed on the station. Printed items up to 50 meters across and 6 meters thick will be used to sheet the truss frame of the station. Beyond these large segments, the printer is also capable of printing other shaped parts of varying size, such as I-beams, triangles, tubes, tanks, and similar components, thereby creating various pressurized modules that will increase the size and volume of the station as well as support other applications. The printer will rely exclusively on station-derived thermoset bio-binder and plant-derived fillers, both of which would be hydroponically grown and processed on the station.

Illustration of Station 520 under construction in MEO. The top is in the process of being enclosed, exposing the internal scaffolding. Credit: Orbital Construction Pioneers

Once operational, Station 520 would become a self-sustaining ecosystem. Waste streams would be fully recycled; oxygen and water continuously regenerated; methane produced from biological waste; and plant fibers would become industrial feedstock. It is believed that outputs will exceed the station’s own needs and could be traded with visiting spacecraft, providing refueling, resupply, and waste-processing services. In this way, FSMS will transform Station 520 into a renewable manufacturing hub that could produce structural mass, life-support commodities, and mission-specific modules. It could become the first practical foundation for a non-Earth-centric orbital economy and simultaneously offer the United States a strategic industrial and defense platform in orbit. It is being positioned as a gateway to the Moon and Mars.

Tyson’s vision doesn’t stop in low Earth orbit. He shared with me a draft paper that he intends to submit for consideration as a presentation at ISDC 2027, of an economic model based on FSMS that lays the foundation for a space-based economy that could extend throughout the solar system. The rest of this post is based on his insights from that paper, with his generous permission.

Progression of Orbital Economic Development

Orbital economic development will follow a predictable sequence analogous to the terrestrial progression from subsistence agriculture to industry and then to commerce. The sequence will be shaped by mass constraints, the necessity of closed-loop life support, and the requirement for continuous production. FSMS will supply the architecture that will enable an orbital station to advance through each stage without reliance on Earth-supplied resources.

The initial stage will be biological sustainability. Hydroponic and aquaponic systems will generat food, oxygen, water, and biomass, forming the ecological base required for long-duration habitation. This stage mirrors early agricultural settlements in which reliable food production enabled population growth and the beginnings of specialization.

The second stage is industrial capability. FSMS converts biological output into structural mass, life-support commodities, and manufacturing feedstock. The transition is analogous to terrestrial industrialization, in which local production of steel, concrete, and machinery enabled large-scale construction and economic expansion. In orbit, manufacturing will break the launch vehicle fairing-size constraint and permit the creation of large rotating habitats, industrial modules, and specialized stations.

The third stage is economic expansion. Once primary and secondary outputs become established, tertiary services will emerge—logistics, crew support, data services, defense infrastructure, and interstation trade. These services will create economic gravity that attracts additional stations, missions, and commercial operators. Over time, specialized stations will form clusters, and clusters will form networks, producing a resilient orbital economy capable of supporting interplanetary operations. This progression will transform Station 520 from a single manufacturing node into a central hub of orbital commerce and will lay the foundation for sustained human presence in cislunar space and eventual expansion to Mars, the asteroid belt, and beyond.

Station 520 as the First Orbital Industrial Hub

Station 520 is designed from the outset to function as an industrial hub rather than a research outpost or mere logistics waypoint. Its scale, closed-loop ecology, and manufacturing capability will allow it to operate as a self-sustaining economic engine. The ability to produce more than it consumes is intentional. Visiting spacecraft will be able to offload waste, receive processed commodities, refuel, resupply, and acquire custom-fabricated components. These exchanges will create predictable traffic patterns and establish the station as a focal point for orbital logistics. Subsequent stations will rely on Station 520 for structural modules, life-support commodities, and specialized manufacturing services. The role is analogous to that of early industrial cities that anchored regional economies by supplying essential goods and services. Station 520 will perform the same function in orbit, serving as the first node in a network of infrastructure that will eventually support interstation trade, defense operations, scientific research, and interplanetary missions.

Cluster Formation and Interstation Trade

When Station 520 begins production, it will naturally attract additional stations seeking reliable supply, fabrication services, and ecological support. Orbital clusters will form through economic gravity rather than centralized planning. Stations will appear where production, logistics, and habitation needs intersect, creating dense regions of activity similar to terrestrial industrial districts. The first cluster will form around Station 520 because it will supply the essential goods required for orbital expansion. Research stations, agricultural modules, logistics depots, defense platforms, and specialized manufacturing nodes will locate nearby to minimize transit time and maximize access to FSMS outputs. As each station specializes, interstation trade will increase, strengthening the entire cluster.

Trade flows will follow predictable patterns. Structural modules will move outward from Station 520 to new construction sites. Life-support commodities will circulate among habitation stations. Waste streams will move inward for processing and conversion into fuel, fertilizer, and industrial feedstock. Data, navigation, and timing services will flow across the cluster, supporting operations and defense. Over time, these exchanges will create a resilient economic ecosystem capable of supporting large populations and complex industrial activity. Cluster formation will mark the transition from isolated stations to interconnected economies, enabling specialization, efficiency, and scalability. As clusters grow, they will become staging points for expansion to lunar orbit, Mars transit routes, and eventually the asteroid belt.

Expansion Beyond Earth Orbit

Once an orbital cluster becomes self-sustaining, expansion beyond Earth orbit will be economically viable. The historic limiting factor for deep-space missions has been mass: every kilogram launched from Earth carries a cost penalty that compounds with distance. By producing structural mass, life-support commodities, and fuel precursors in orbit, FSMS will eliminate much of this penalty and enable missions that would otherwise be infeasible.

The first stage is cislunar expansion. Stations positioned at Earth–Moon Lagrange points or in lunar orbit will rely on Station 520 for construction modules, ecological support, and resupply. These stations will specialize in mining, scientific research, logistics, or defense. Their proximity will permit efficient trade and form the first interorbital economic corridor.

The second stage is Mars transit. Large rotating habitats fabricated in orbit will provide artificial gravity, radiation protection, and closed-loop life support for long-duration missions. Instead of launching fully assembled transit vehicles from Earth, FSMS will enable modular construction in orbit, reducing launch mass while increasing mission size and flexibility. Transit vehicles will be refueled, repaired, and upgraded at Station 520 before departure.

The third stage is the asteroid belt. Resource extraction becomes economically viable only when processing and manufacturing occur near the source. FSMS-derived technologies such as large rotating habitats, closed-loop ecology, and modular fabrication will enable industrial operations in deep space. Stations built in orbit will become templates for asteroid-based manufacturing hubs capable of producing metals, volatiles, and industrial feedstock. Expansion beyond Earth orbit will therefore be the natural consequence of establishing a functional orbital economy. Once mass can be produced in space, the solar system will become accessible in a manner that Earth-launched missions alone cannot achieve.

Strategic Implications for the United States

A functional orbital economy will be both an industrial achievement and a strategic asset. Nations that control orbital manufacturing, logistics, and closed-loop ecological systems will shape the future of space commerce, defense, and exploration. Station 520 will provide the United States with the first platform capable of sustaining large-scale orbital operations without continuous Earth resupply, establishing a durable advantage in cislunar space.

Manufacturing in orbit will break the launch-vehicle constraint that currently limits the size and capability of U.S. orbital assets. Large rotating habitats, industrial modules, and defense platforms can be built and maintained without the limitations of Earth’s gravity well. This strengthens national security by enabling resilient infrastructure that cannot be easily disrupted by terrestrial launch bottlenecks or adversary interference. Closed-loop ecological systems will provide strategic endurance: stations that produce food, water, oxygen, and fuel locally can operate indefinitely, supporting long-duration missions, rapid response, and persistent presence in critical orbital regions. They also allow the United States to support allied missions, humanitarian operations, and scientific research without overburdening terrestrial logistics. Interstation trade and cluster formation will create strategic depth. A distributed network of specialized stations will support defense, commerce, and exploration while reducing vulnerability and increasing operational flexibility. The same capabilities extend beyond Earth orbit, enabling construction of Mars transit vehicles, asteroid-belt industrial hubs, and deep-space research stations. By establishing the first functional orbital economy, the United States positions itself to lead the next era of human expansion into the solar system.

The Economic Path to a Solar-System Civilization

The emergence of an orbital economy will mark a fundamental shift in humanity’s relationship with space. For six decades, orbital activity has been constrained by Earth’s gravity well, limited launch mass, and the absence of local production. FSMS will break these constraints by enabling continuous, renewable manufacturing in orbit. With Station 520 the United States could establish the first platform capable of producing structural mass, life-support commodities, and industrial feedstock without reliance on Earth-supplied resources.

This capability will transform orbital stations from isolated outposts into interconnected economic actors. Primary outputs will create the foundation for habitation and construction. Secondary outputs will expand industrial capability and ecological resilience. Tertiary outputs will generate logistics, services, and strategic infrastructure. Together, these layers will form a scalable economic architecture capable of supporting clusters, trade networks, and deep-space missions. Once mass can be produced in orbit, expansion beyond Earth will become economically inevitable. Cislunar stations, Mars transit vehicles, and asteroid-belt industrial hubs will follow naturally from the ability to fabricate large structures and sustain crews without continuous resupply. The solar system will become accessible not primarily through larger rockets but through the emergence of a functional orbital economy.

Station 520 is the first step in this transformation. It will supply the United States with a durable industrial foothold in orbit, generate economic gravity that attracts additional stations, and lay the foundation for a solar-system civilization built on renewable orbital manufacturing. The path forward is clear: build the economy first, and the civilization will follow. Orbital Construction Pioneers is blazing the trail with FSMS.

3D printing Mars habitats using in-situ resources

Conceptual illustration of a habitat on Mars being 3D printed with a regolith-based mixture using a direct ink writing technique. The configuration is inspired by the MARSHA habitat concept proposed by SpaceFactory. Credit: Marcelo Tramontin Souza, Figure 1 from open access article in Acta Astronautica with minor text edits / Used under CC by 4.0

Imagine trying to build a house on Mars. All the materials you need would have to be imported from Earth on a rocket that costs tens of thousands of dollars per kilogram to launch. Aerospace engineers and advocates for space settlement know that in-situ resource utilization (ISRU)—using materials already on Mars instead of shipping everything from home – is the key to sustainable and affordable settlement of Mars (and elsewhere in the solar system, for that matter). A review paper by Brazilian researcher Marcelo Tramontin Souza in the forthcoming issue of the journal Acta Astronautica, pulls together the latest research on one of the most promising ways to do this: 3D printing (additive manufacturing) habitats directly from Martian regolith. This post explains the paper’s main ideas, why they matter, the biggest challenges, and what the future might look like.

Why Mars Habitats Would Benefit from 3D Printing Using Local Materials

Sending humans to Mars is currently incredibly expensive. One early estimate puts the cost of the first crewed mission at around $500 billion, with most of that money going toward hardware, launch, and operations. This estimate has the caveat that it was made prior to SpaceX significantly reducing launch costs through the company’s continuous optimization of the reusability of its Falcon 9 launch vehicle and the anticipated $100M/ton delivered to the Martian surface with Starship. Even if the cost may be quite a bit lower, it will still be cost-prohibitive to bring everything from Earth.

The biggest single issue is, of course, Mass. Every kilogram of building material launched from Earth adds huge costs in rocket fuel. Once on Mars, astronauts will need safe places to live that protect them from the planet’s deadly environment: a paper-thin carbon-dioxide atmosphere (only about 0.6% of Earth’s pressure), average temperatures of –60 °C with swings up to 100 °C in a single day, no magnetic field to block cosmic radiation, toxic perchlorate salts in the soil, and dust storms that can last for months.

Traditional ideas—shipping pre-built modules and assembling them on the surface—still require launching tons of material. ISRU flips the script by mining and processing local resources on site. Souza’s paper focuses on additive manufacturing, or 3D printing, because it can be automated easily, wastes almost no material, and can create complex shapes layer by layer from digital designs. In this scenario, robots would excavate regolith, mix it into printable “ink,” and build protective shells around inflatable living quarters. This approach could let early outposts grow into self-sustaining colonies without constant resupply from Earth.

The paper reviews three main categories of 3D-printing technologies adapted for Mars: low-temperature extrusion (like giant concrete printers), medium-temperature thermoplastic (sulfur-based “Martian concrete”), and high-temperature sintering (melting or fusing regolith with solar, microwave, or laser heat). It also covers habitat designs, radiation shielding, structural engineering under Mars conditions, energy needs, and remaining technology gaps.

What Martian Regolith Is Really Like—and Why It’s Both Useful and Tricky

The loose, dusty regolith on Mars formed from billions of years of meteorite impacts, wind erosion, and limited chemical weathering of the planet’s basaltic crust. Chemically, it is roughly 40–50% silica (SiO₂), 10–15% aluminum oxide, 10–20% iron oxides, plus magnesium, calcium, sulfur, and traces of other elements—very similar to Earth basalt but with more variability from site to site. Grain sizes are mostly silt to fine sand, which helps flow in printers but can clump in low gravity. About 25–60% of it is amorphous (non-crystalline) material, which is great for chemical reactions but unpredictable.

Key challenges include:

  • Perchlorates (0.5–1% by weight) are toxic to humans and plants and can interfere with binders.
  • Low pressure (~600 Pa) makes water boil or freeze instantly, so water-based materials are hard to use on the open surface.
  • Temperature swings cause cracking from repeated expansion and contraction.
  • Radiation: Surface dose is ~200–250 mSv per year—far above Earth’s safe limits. Regolith is a good shield, but you need about 1–3 meters of it to cut exposure dramatically.
  • Dust and wind: Fine particles stick to everything and abrade surfaces.

The paper provides a summary of regolith properties: bulk density 1.1–1.6 g/cm³, solid density ~3 g/cm³, angular particles for good interlocking and low thermal conductivity when gathered in loose piles (good for insulation).

To model Martian soil with these characteristics, regolith simulants like JSC Mars-1A, MGS-1, and HIT-MRS-1 are used on Earth to test ISRU scenarios because they match these properties with respect to chemistry and grain size.

The Three Main 3D Printing Approaches for Mars Construction

Souza organizes the technologies by temperature and binder needs. Each has strengths for different mission phases.

1. Extrusion-Based Printing (Low-Temperature, ~20–80 °C curing) – The Most Mature Option
This is like the giant concrete printers already used on Earth for houses. A robotic arm or gantry extrudes a thick paste of regolith mixed with a geopolymer binder (alkali-activated, similar to ancient Roman concrete but made from local minerals). Studies like one of the references in the paper by Ma et al. (2022) mixed HIT-MRS-1 simulant with sodium silicate and NaOH, then added basalt fibers for toughness. They printed bio-inspired shapes—honeycomb, helical, suture-like patterns—that turn brittle material into damage-tolerant structures achieving up to 32 MPa compressive strength.

The major problems on Mars for this method include:

  • Needs water and imported alkaline chemicals (hard to make locally at scale).
  • Curing fails in vacuum and cold: water evaporates or freezes, creating weak, porous parts.
  • Solution: Print inside a pressurized, heated inflatable enclosure (like the MARSHA concept from AI SpaceFactory) and use localized heaters or microwaves to speed curing.

Pros: Scalable for large structures, proven on Earth analogs like NASA’s Mars Dune Alpha (ICON’s 3D printed habitat).
Cons: High Earth-dependence early on; slow curing (hours to days).

2. Thermoplastic Extrusion – Sulfur “Martian Concrete” (120–150 °C)
Sulfur is abundant on Mars in sulfates. It can be melted, mixed with ~50% regolith, extruded or casted, and it will harden in minutes as it cools—no water needed. Wan et al. (2016) and Giwa et al. (2024) showed compressive strengths of 35–60 MPa, with additives like dicyclopentadiene (DCPD) improving flexibility and reducing sublimation in vacuum

Advantages: Fully ISRU-compatible once sulfur is extracted, can be processed quickly, is recyclable by remelting, and works in a vacuum. Domes and blocks are easy to print or cast.
Drawbacks: Brittle at low temperatures; may crack during thermal cycles of Martian days, which can have temperature swings of up to 100 °C; sulfur can sublimate (turn directly from solid to gas) if hot. Long-term durability under repeated freeze-thaw cycles is poor without modifiers.

3. Binder-Free Sintering (High-Temperature, >1000 °C) – Solar, Microwave, or Laser
Heat regolith until particles fuse like pottery or glass. No imported binders—just pure local dirt.

  • Solar sintering: Concentrate sunlight with lenses or mirrors. Mars gets less sunlight than Earth (~590 W/m² at the top of the atmosphere vs. 1361 W/m²), but the thin atmosphere means almost no convective cooling, so efficiency is surprisingly good. A study by Deng et al. (2025) showed basaltic regolith sinters well with optimized particle size. Layer-by-layer printing could build graded structures (dense outside for strength, porous inside for insulation).
  • Microwave sintering: Iron-rich regolith absorbs microwaves volumetrically (heats from inside out). Fast but hard to control; risks cracking from uneven heating.
  • Laser sintering: Great for small, precise parts (tools, brackets) inside a habitat, but too slow and energy-hungry for full-size buildings.

These methods depend fully on ISRU but are energy-intensive (10–100 MJ per kg vs. ~1–2 MJ/kg for extrusion) and sensitive to dust on optics or variations in regolith chemistry.

Robotic systems (rovers for excavation, gantry arms for printing, sensors for real-time monitoring) and energy sources (solar + nuclear backup) are critical across all methods.

Habitat Designs: From Inflatable Cores to Printed Shells

Early habitats will likely be hybrid: lightweight inflatable modules flown from Earth, then covered by 3D printed or piled regolith for protection. Inflatable pressure vessels handle internal Earth-like air pressure (~50–100 kPa). Regolith overburden (1–3 m thick) blocks radiation, insulates against temperature swings, and stops micrometeorites and dust.

  • Loose regolith burial: Fast and cheap but risks settling, dust infiltration, and uneven loading.
  • Consolidated regolith shells: 3D print a rigid outer layer first, then pile loose dirt on top. This distributes loads, stops dust migration, and allows graded porosity for better shielding.
  • Fully printed or subsurface options: Lava tubes or excavated trenches offer natural shielding; printed domes or cylinders provide long-term durability.

Radiation modeling (using GEANT4 simulations) shows that a one-meter layer of regolith cuts the dose by ~70%; 3 meters brings the exposure down near Earth background levels. Thermal buffering from regolith also reduces heating/cooling needs.

Structural Challenges Under Martian Conditions

Mars is not Earth (obviously):

  • Internal pressure: The habitat must hold ~1 atm inside against near-vacuum outside. Printed layers must be airtight (often needing internal liners).
  • Low gravity (0.38g): Implies less structural loads but also less compaction during printing; soil bearing capacity changes may arise.
  • Marsquakes: The InSight Lander, which sent its last transmission December 15, 2022 after a successful four-year mission, recorded hundreds of small events (magnitude ~1–4). They last minutes with low damping, so long vibrations could fatigue structures, but they are too weak to cause collapse.
  • Thermal cycling and dust abrasion: Printed layer interfaces are weak points.

Habitat designers must use finite-element modeling, taking into account the above environmental factors, consider interactions between the soil and structure, and build in redundancy. To the authors’ knowledge, no studies have yet performed integrated simulations combining all these factors, which is a major research gap.

Energy, Scalability, and Real-World Trade-Offs

Energy is the hidden killer. Extrusion is relatively inexpensive with respect to power needs, but requires imported binders. Sintering uses only local materials but demands 10–100 times more energy per kilogram. Early missions will favor low-energy extrusion inside enclosures, while later ones can go fully solar-sintered. Robots must work autonomously for years in dust and cold—this is still a significant engineering hurdle.

In comparing the main Martian habitat design approaches, Souza summarizes their advantages, limitations, and associated trade-offs in terms of construction complexity, radiation protection, structural performance, and operational feasibility. Loose burial will be the fastest for initial crews; hybrid printed shells offer the best long-term balance; full subsurface or printed habitats are the ultimate goal, but need mature ISRU technologies.

Prospects, Gaps, and the Road Ahead

Souza is optimistic but realistic. 3D printing combined with ISRU is the most promising path to sustainable Mars habitats because it significantly reduces launch mass and enables rapid expansion. Near-term wins could come from sulfur concrete for quick protective barriers and geopolymer printing inside controlled environments. In the long term, binder-free sintered regolith has the potential to create entire self-repairing cities.

Conceptual illustration of an autonomous 3D printing system constructing a Martian shelter using sulfur-based concrete, deposited layer by layer from locally sourced materials. Credit: Marcelo Tramontin Souza, Figure 3 from open access article in Acta Astronautica with minor text edits / Used under CC by 4.0

The key remaining challenges include:

  • Making binders 100% from Mars resources.
  • Proving long-term durability (thermal cycling, radiation protection, perchlorate mitigation).
  • Scaling robots and energy systems.
  • Sealing printed structures for pressurization.
  • Integrating life support, greenhouses, and expansion.

The paper calls for more analog testing on Earth (e.g., in deserts and vacuum chambers), international collaboration, and hybrid approaches that combine the best of each method. Dual-use benefits for Earth include better disaster-resistant 3D printed buildings in remote areas.

In the end, Souza’s review shows that Mars habitats won’t arrive fully formed, delivered from Earth on rockets. They will be grown, layer by layer, from the Red Planet’s own dirt—made robust and resilient by smart engineering, powered by the Sun and nuclear energy, and built by tireless robots. This technology will enable humans to live on the Red Planet permanently and, one day, turn humanity into a true multi-planetary species. The next decade of research will decide how quickly that vision becomes reality.

ICON awarded $57 Million by NASA to develop lunar 3D printing technology for lunar surface construction

Conceptual illustration of Olympus, a lunar construction system based on in situ resource utilization. Credits: ICON

In a press release, the Austin based company reports how the Phase III award under NASA’s Small Business Innovation Research (SBIR) program will be used to adapt its existing additive manufacturing process for home building on Earth to the Olympus system using lunar regolith for fabrication of structures on the Moon. ICON envisions the system to be integrated into a rover that will be delivered to the Moon via a lander. The rover will then autonomously drive to a target site where the Olympus laser 3D printer will process lunar regolith into useful structures. The system can be used for fabricating roads, landing pads and habitats out of local resources without having to bring building materials from Earth, thereby significantly lowering costs. Once the system is proven on the Moon, perhaps in the later stages of Artemis, the same technology can be applied on Mars as well.

ICON plans to test the system “…via a lunar gravity simulation flight” although no details were revealed on such a mission. Presumably, this would be a parabolic flight in the Earth’s atmosphere. The company would use samples of lunar soil brought back during the Apollo missions and lunar regolith simulant to tune the process variables of their laser 3D printing equipment operating under these conditions. Once optimized, Olympus would be placed on the Moon “…to establish the critical infrastructure necessary for a sustainable lunar economy including, eventually, longer term lunar habitation.”

“The final deliverable of this contract will be humanity’s first construction on another world, and that is going to be a pretty special achievement.”

– Jason Ballard, ICON co-founder and CEO

Self-replicating “living” machines for lunar settlement

Conceptual illustration of a self-replicating machine. Source: Wikipedia

In a 2020 paper in the journal Biomimetics, Alex Ellery who heads the Space Exploration Engineering Group in the Department of Mechanical & Aerospace Engineering at Carleton University, Ottawa, lays out a case for engineering mechanical systems that emulate biological life in the same vain as a Von Neumann universal constructor. This concept, conceived by the Hungarian-American mathematician John von Neumann in 1940s prior to the invention of the computer, is a machine that can make copies of itself given a set of instructions, sufficient materials and a source of energy.

Ellery begins by examining theories on the origin of life on Earth to distill down the essence of how inanimate material was transformed into living systems. He then goes on to define the basic characteristics of how organisms use energy to process materials to evolve and reproduce. Applying these principles to mechanical systems he envisions bioinspired machines be used to propagate self-replicating factories on the Moon in a lunar industrial ecology. Materials mined in situ by robots would be processed using solar energy via automated additive manufacturing processes analogous to living organisms reproducing to expand the facility.

“Adopting the notion of a biological ecosystem, we can envisage a modest self-sustained metabolism.”

In an examination of what life is, Ellery makes the analogy between ribosomes, the basic macromolecular machine that performs protein synthesis in living cells, and a 3D printer called the Replicating Rapid Prototyper (or RepRap), a key element of his research. Through additive manufacturing this device can print some of its own plastic components.

RepRap 3D printer comprising a Cartesian robot with extruder head (Figure 2 in the paper) capable of printing copies of some of its own plastic components.. Credits: Alex Ellery

Eventually, Ellery’s goal is for the device to be able to fabricate most of its own parts including the metal components. However, a fully autonomous self-replicating machine will required considerable advancements in artificial intelligence and automation. Initially, prefabricated complex components such as electronic circuitry, actuators, and sensors may be supplied independently as “vitamins” from Earth and assembled automatically during fabrication to enable automatic manufacture of the robots. Ellery introduces his team and describes his research at Carlton University in this short video.

Self-replicating factories designed for the production of space settlement infrastructure have been covered previously by SSP. Hybrid approaches that include humans in the loop to guide the process may be a near term solution until AI and robotic technologies become fully autonomous.

Some have postulated that if Von Neumann probes have been used by alien civilizations to colonize the galaxy there may be ways to detect them.

Converting orbital trash to treasure with CisLunar Industries’ Micro Space Foundry

Illustration of orbital debris recycling. Instead of deorbiting after a few missions, debris removal spacecraft can refuel themselves with metal propellant using the Micro Space Foundry extending the lifespan and lowering costs. Credits: CisLunar Industries

CisLunar Industries is developing an innovative way to clean up Earth orbit by recycling spent rocket stages and other orbital debris using their Micro Space Foundry (MSF). In a March 2 presentation to the Future In-Space Operations telecon, CisLunar CEO Gary Calnan described the technology and markets for the MSF, development of which was funded by an SBIR/STTR grant from NASA. There is a vast untapped value chain of metals high above our heads. Over the last 60 years as satellites have been launched into space, the used upper stages have been cluttering up low Earth orbit and beyond. But the trash has value because it is useful material in orbit that has already incurred the launch cost.

The system works by robotically cutting aluminum feedstock off of derelict satellites and then processing the metal through the MSF using electromagnetic levitation furnace technologies originally proven on the ISS for virtually contactless metal recycling and reuse in a weightless environment. The MSF spits out rods of “fuel” to feed a Neumann Thruster on the debris removal spacecraft, which can then be powered to deorbit the target satellite and move on to its next destination. Rinse and repeat. The architecture has the potential to change the economics of the cislunar economy by harvesting a valuable in situ resource while cleaning up Earth orbit at the same time.

The Neumann Thruster, invented by Dr. Patrick “Paddy” Neumann, is an electric propulsion system for in-space use which is a highly adjustable, efficient and scalable method for moving satellites where they are needed. The Neumann Drive uses solid metal propellant and electricity to produce thrust via a pulsed cathodic arc system analogous to an arc welder. Neumann, who created the company Neumann Space to commercialize his invention, explains the physics behind the thruster in a video of an early prototype.

CisLunar Industries has other applications planned for the MSF in an emerging in-space ecosystem. In addition to extruding metallic rods as propellant, the system can fabricate long tubes for large-scale space structures or wires for additive manufacturing enabling an in-space commodities value chain and creating demand for processed metals.

Conceptual illustration of the MSF core processing unit, utilizing a modular design to enable lower cost flexible deployment and multiple products in an emerging cislunar economy. Credits: CisLunar Industries

So how mature is the technology? CisLunar has already demonstrated component validation in the lab taking the system to TRL 4. You can see a video documenting the experiment at timestamp 35:54 here. A parabolic flight to run an experiment in simulated weightlessness is scheduled for later this year. Actual in-space end-to-end demonstration with a Neumann Thruster is planned in 2024 via an agreement with Australian space services company Skykraft.

Self replicating factories for space settlement

Artist’s illustration of a self replicating factory near an asteroid and serviced by a SpaceX Starship. Credits: Michel Lamontagne / Principium

The technology of self replicating machines has been gradually progressing toward maturity over the last few decades. The Space Studies Institute recognized this key enabler of space settlement as far back as the 1980s and covered the topic frequently in its newsletter updates. Now Michel Lamontagne has provided a status update in the latest issue of Principium. On page 50, he highlights the history of self replicating factories, provides a vision for the evolution of the concept for production of space settlement infrastructure and gives a summary of recent developments in key areas of research such as additive manufacturing, machine learning and cheap access to space that will be enablers of this space based industry.

The first factory will be built on the Moon after deep learning simulations prove the concept on Earth. Eventually the more autonomous versions would migrate to Mars and then to what may be the best suited location, the asteroid belt which “…may be the ultimate resource for space settlement construction.” Lamontagne believes “These factories would then follow humanity to the Stars, after having helped to build the infrastructure required for the occupation of the solar system and for Interstellar travel.”

Artist’s rendering of an early self replicating factory on the Moon with SpaceX Starships serving as basic construction elements. Credits: Michel Lamontagne / Principium

Project MOONRISE demonstrates 3D printed regolith structures under lunar gravity conditions

Artist impression of the MOONRISE laser mounted on a lunar rover for fabrication of structures on the Moon. Credits: Laser Zentrum Hannover / 3D Printing Industry

A German company called Laser Zentrum Hannover .eV in partnership with the Technical University of Braunschweig has been working on a project called MOONRISE which aims to use laser technology to build a village on the Moon out of lunar regolith. Toward that end, the team for the first time has demonstrated the ability to 3D print structures out of simulated lunar regolith under lunar gravity conditions. The results of their experiments are described in an article in 3D Printing Industry.

The research was carried out in the Leibniz University Hannover’s Einstein-Elevator, a large-scale drop tower device in which experiments can be run under variable gravity conditions at a high repetition rate.

Initiated in 2019, Project MOONRISE is funded by the Volkswagen Foundation and is focused on improving the technology readiness level of additive manufacturing using lunar regolith as building material.

Martian in situ manufacturing using chitosan biolith

Illustration of three applications of chitosan derived Martian biolith cast into different geometries including a wrench, freeformed material or an additive manufactured habitat model. Credits: Ng Shiwei, Stylianos Dritsas, Javier G. Fernandez via PLOS ONE

Working with simple chemistry suitable for an early Martian settlement, a team of researchers in Singapore has demonstrated that Martian biolith using chitosan derived from shrimp, with minimal energy requirements, could be used for rapid manufacturing of objects ranging from basic tools to rigid shelters. Ng Shiwei, Stylianos Dritsas, and Javier G. Fernandez publish their results in a paper in PLOS ONE.

Chitosan is chemically derived from chitin, the organic matrix produced by biological organisms incorporating calcium carbonate into rigid structures. Chitin would be a byproduct of food production in a closed-loop life support system on Mars.

Chitosan can form transparent objects similar in appearance and mechanical properties to plastic, which would be lacking in early stage Mars settlements. When processed with Martian regolith, the resulting Chitosan biolith produces a material with good mechanical properties and general utility for manufacturing on Mars.

Redwire manufactures the first 3D printed ceramic in space

Image of Ceramics Manufacturing Module (CMM), a commercial manufacturing facility that produces ceramic parts in microgravity for terrestrial use. Credits: Redwire/Made in Space

Made in Space, a recent acquisition of Redwire, has just for the first time successfully manufactured a ceramic part in their Ceramics Manufacturing Module on the ISS using additive manufacturing. The demonstration could stimulate demand in low Earth orbit from terrestrial markets which will be a key driver for space industrialization. Redwire claims that the parts, which included a turbine blisk (bladed disk) and other test pieces, demonstrate that the CMM can produce ceramic parts that exceed the quality of turbine components made on Earth.

According to Redwire’s press release: “CMM aims to demonstrate that ceramic manufacturing in microgravity could enable temperature-resistant, reinforced ceramic parts with better performance, including higher strength and lower residual stress. For high-performance applications such as turbines, nuclear plants, or internal combustion engines, even small strength improvements can yield years-to-decades of superior service life.”

Image of CCM 3D printed part fabricated in LEO. Credits: Redwire

Making oxygen from moondust with ROXY (and improving life on Earth)

Artist’s rendition of Airbus lunar lander with ROXY on board. Credits: Airbus

In a breakthrough experiment last month, a team led by Airbus Defence and Space (Friedrichshafen, Germany) has for the first time produced oxygen and other metals from simulated lunar soil with a proprietary process called Regolith to OXYgen and Metals Conversion, or ROXY. The revolutionary new process could be the core of an ISRU value chain on the moon, providing oxygen for habitats or rocket fuel, with added byproducts of metals and alloys as feedstock for additive manufacturing of building materials. This would significantly reduce the cost of settlements on the Moon as the construction materials could be fabricated in situ, without the need to be brought from Earth. Check out Airbus’ animation of ROXY here.

Airbus thinks that the ROXY reactor could have beneficial environmentally friendly applications on Earth as well:

“On Earth, ROXY opens a new pathway to drastically reduce the emissions of greenhouse gases that result from production of metals.” Since the process is essentially free of emissions “…these environmental impacts could be reduced, providing a significant contribution to the UN sustainability goals – another example of how space technologies can improve life on Earth”