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.

Greater Earth (GE⊕) Lunar Power Station

Conceptual illustration showing the first iteration of the proposed design of a GE⊕ Lunar Power Station beaming power to facilities on the Moon. Credit: Astrostrom

In response to ESA’s Open Space Innovation Platform Campaign on Clean Energy – New Ideas for Solar Power from Space, the Swiss company Astrostrom laid out a comprehensive plan last June for a solar power satellite built using resources from the Moon. Called the Greater Earth Lunar Power Station (GE⊕-LPS, using the Greek astronomical symbol for Earth, ⊕ ), the ambitious initiative would construct a solar power satellite located at the Earth-Moon L1 Lagrange point to beam power via microwaves to a lunar base. Greater Earth and the GE⊕ designation are terms coined by the leader of the study, Arthur Woods, and are “…based on Earth’s true cosmic dimensions as defined by the laws of physics and celestial mechanics.” From his website of the same name, Woods provides this description of the GE⊕ region: “Earth’s gravitational influence extends 1.5 million kilometers in all directions from its center where it meets the gravitational influence of the Sun. This larger sphere, has a diameter of 3 million kilometers which encompasses the Moon, has 13 million times the volume of the physical Earth and through it, passes some more than 55,000 times the amount of solar energy which is available on the surface of the planet.”

GE⊕-LPS would demonstrate feasibility for several key technologies needed for a cislunar economy and is envisioned to provide a hub of operations in the Greater Earth environment. Eventually, the system could be scaled up to provide clean energy for the Earth as humanity transitions away from fossil fuel consumption later this century.

One emerging technology proposed to aid in construction of the system is a lunar space elevator (LSE) which could efficiently transport materials sourced on the lunar surface to L1. SSP explored this concept in a paper by Charles Radley, a contributor to the Astrostrom report, in a previous post showing that a LSE will be feasible for the Moon in the next few decades (an Earth space elevator won’t be technologically possible in the near future).

Another intriguing aspect of the station is that it would provide artificial gravity in a tourist destination habitat shielded by water and lunar regolith. This facility could be a prototype for future free space settlements in cislunar environs and beyond.

Fabrication of the GE⊕-LPS would depend heavily on automated operations on the Moon such as robotic road construction, mining and manufacturing using in situ resources. Technology readiness levels in these areas are maturing both in terrestrial mining operations, which could be utilized in space, as well as fabrication of solar cells using lunar regolith demonstrated recently by Blue Origin. That company’s Blue Alchemist’s process for autonomously fabricating photovoltaic cells from lunar soil was considered by Astrostrom in the report as a potential source for components of the GE⊕-LPS, if further research can close the business case.

Most of the engineering challenges needed to realize the GE⊕-LPS require no major technological breakthroughs when compared to, for example (given in the report), those needed to commercialize fusion energy. These include further development in the technologies of the lunar space elevator, in situ lunar solar cell manufacturing, lunar material process engineering, thin-film fabrication, lunar propellent production, and a European heavy lift reusable launch system. The latter assumes the system would be solely commissioned by the EU, the target market for the study. Of course, cooperation with the U.S. could leverage SpaceX or Blue Origin reusable launchers expected to mature later this decade. With respect to fusion energy development, technological advances and venture funding have been accelerating over the last few years. Helion, a startup in Everett, Washington is claiming that it will have grid-ready fusion power by 2028 and already has Microsoft lined up as a customer.

Astrostrom estimates that an initial investment of around €10 billion / year over a decade for a total of €100 billion ($110 billion US) would be required to fund the program. They suggest the finances be managed by a consortium of European countries called the Greater Earth Energy Organization (GEEO) to supply power initially to that continent, but eventually expanding globally. Although the budget dwarfs the European Space Agency’s annual expenditures ( €6.5 billion ), the cost does not seem unreasonable when compared to the U.S. allocation of $369 billion in incentives for energy and climate-related programs in the recently passed Inflation Reduction Act. The GE⊕-LPS should eventually provide a return on investment through increasing profits from a cislunar economy, peaceful international cooperation and benefits from clean energy security.

The GE⊕-LPS adds to a growing list of space-based solar power concepts being studied by several nations to provide clean, reliable baseload energy alternatives for an expanding economy that most experts agree needs to eventually migrate away from dependence on fossil fuels to reduce carbon emissions. Competition will produce the most cost effective system which, coupled with an array of other carbon-free energy sources including nuclear fission and fusion, can provide “always on” power during a gradual, carefully planned transition away from fossil fuels. The GE⊕-LPS is particularly attractive as it would leverage resources from the Moon and develop lunar manufacturing infrastructure while serving a potential tourist market that could pave the way for space settlement.

Artificial photosynthesis for production of oxygen and fuel on the Moon and Mars

Image of ice in a crater on the Martian plain Vastitas Borealis captured by the European Space Agency’s Mars Express orbiter. Credits: ESA/DLR/Freie Universitat Berlin (G. Neukum)

When we establish outposts and eventually, settlements on the Moon or Mars it would be economically beneficial if we did not have to create supply chains from Earth for water, breathable air and the fuel we will need for our rockets. This is why sources of water ice in the permanently shadowed craters at the lunar poles and in glaciers in the equatorial regions on Mars are so attractive as early destinations. Once we get there what equipment will we need to process this valuable resource? The typical way envisioned for cracking water in situ on the Moon or Mars to produce oxygen and hydrogen is through electrolysis. But this method requires a lot of power. There may be a more efficient way. New ESA sponsored research by scientists* in the UK and Europe examines a novel method that mimics photosynthesis in plants using a photoelectrochemical (PEC) device. The findings were published June 6 in Nature Communications.

PEC reactors are currently being studied on Earth for water splitting to produce green hydrogen from sunlight. Since they only rely on solar energy for power they are ideal for space applications. One type of device consists of a semiconductor photocathode immersed in an electrolyte solution that absorbs solar energy for a reaction to split hydrogen from water molecules. Oxygen is produced at the anode of the cell. PEC devices can be fabricated as panels similar to photovoltaic arrays. For use on Mars, the authors analyze another similar PEC technology using a gas-diffusion electrode to reduce atmospheric carbon dioxide in a reaction producing methane for rocket fuel.

The authors modeled the performance of these devices subjected to the expected environmental conditions on the Moon and Mars. Specifically, they looked at attenuation from the accumulation of dust on the PEC cells caused by micrometeorites pulverizing the lunar surface, coupled with the solar wind inducing an electrostatic charge in the resulting dust. And of course dust storms are relatively frequent on Mars which could significantly degrade performance. To address this problem self cleaning coatings are suggested as a solution. Solar irradiance was also considered as it would be reduced at the orbit of Mars. It was concluded that the PEC performance could be significantly boosted with solar concentrators by a factor of 1000 enabling higher production rates and power densities, especially on Mars.

An added advantage for space-based application of this technology is the elements needed to construct PEC devices are readily available on these worlds obviating the need to transport them from Earth and thereby significantly reducing costs.

“…in-situ utilization of elements on both, the Moon and Mars, is feasible for the construction of PEC devices.”

The technology is ideal to augment the production of oxygen in environmentally controlled life support systems of habitats that may not initially be 100% closed and cannot easily be resupplied with consumables from Earth. A competing technology for oxygen production which was recently demonstrated on Mars is the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) which functions via solid oxide electrolysis of carbon dioxide. This process requires high temperatures and therefore, more energy presenting a challenge when increased production of oxygen will be required for large settlements. The author’s analysis show that the PEC devices are more energy efficient and can easily be scaled up.

“Oxygen production via unassisted PEC systems can … be carried out at room temperature … suitable to be housed in temperature controlled space habitats.”


* Authors of the Nature Communications article Assessment of the technological viability of photoelectrochemical devices for oxygen and fuel production on Moon and Mars: Byron Ross at the University of Warwick, UK; Sophia Haussener at Ecole Polytechnique Fédérale de Lausanne, Switerland; Katharina Brinkert, University of Bremen, Germany


Space solar power developments in 2022

Conceptual illustration of ESA’s SOLARIS space based solar power system. Credits: ESA

This year there were a lot of announcements and commentary regarding government support for studies that may lead to actual development activities for space solar power. These events, as well as some efforts by private companies, have been prompted by global initiatives to reduce carbon emissions toward net zero by midcentury in the hope of mitigating climate change.

Last January Japan codified into law an aggressive timetable to launch an end-to-end space solar power demonstration flight in LEO by 2025. From an English translation of Japan’s Basic Space Law provided by the National Space Society, the exact text reads “Each ministry will work together to promote the realization of space solar power generation. Concerning microwave-type space solar power generation technology, the aim will be to demonstrate by 2025 energy transmission from low Earth orbit to the ground.” If implemented on time, this would be the first such technical demonstration to be performed from space. Also, the fact that the initiative is codified into Japan’s laws means they are serious.

At a Royal Aeronautical Society conference last April in London called Toward a Space Enabled Net-Zero Earth, chairman of the Space Energy Initiative Martin Soltau outlined a 12-year timeline that would provide gigawatts of power from space for the UK by 2035. The Initiative, which is a collection of over 50 British technology organizations, has selected a space solar power satellite design called CASSIOPeiA after a cost benefit analysis performed by Frazer-Nash Consultancy initially covered by SSP. Incidentally, links to the final report by Frazer-Nash Consultancy completed in September 2021 and to the CASSIOPeiA system are available on the SSP Space Solar Power page.

At the International Space Development Conference in Washington D.C. last May, Nickolai Joseph of the NASA Office of Technology Policy, and Strategy (OTPS) announced an effort by the space agency to reexamine space based solar power. The purpose of the study is to assess the degree to which NASA should support its development.  Joseph said the report was to be completed by the end of September but as this post goes to press, it had not been released. Head of the OTPS, Bhavya Lal, tweeted last month that the report was in final review but this Tweet has been deleted without explanation. We are still waiting.

Three items on space solar power came up in September. First, John Bucknell returned to The Space Show to give an update on Virtus Solis, his space-based power system that SSP covered previously in an interview. With the novel approach of a Molynia sun-synchronous orbit, Bucknell claims that Virtus Solis will provide baseload capacity at far lower cost. In addition, the choice of orbits allow sharing orbital assets globally enabling solutions for multiple countries and regions. Bucknell hopes to have a working prototype to test in space within the next few years.

Schematic illustration of a three-array Virtus Solis constellation in Molniya orbits serving Earth’s Northern Hemisphere and a two-array constellation serving the Southern Hemisphere of Luna. Credits: Virtus Solis

Later in the month, the American Foreign Policy Council published a position paper on space based solar power in the organization’s publication Space Policy Review. From the introduction, author Cody Retherford writes that space solar power “…satellites are a critical future technology that have the potential to provide energy security, drive sustainable economic growth, support advanced military and space exploration capabilities, and help fight ongoing climate change.”

Overview of Space-based Solar Power from Figure 1 in American Foreign Policy Council report. Credits: AFPC and U.S. Department of Energy.

Also in September, the European Space Agency proposed a preparatory program called SOLARIS to inform a future decision by Europe on space-based solar power. The proposal was submitted for consideration in November at the ESA Council at Ministerial Level held in Paris.

The goal of SOLARIS, conceptualized in the illustration at the top of this post, would be to lay the groundwork for a possible decision in 2025 to move forward on a full development program to realize the technical, political and programmatic viability of a space solar power system for terrestrial needs.

Upon the conclusion of the ESA Council at Ministerial Level meeting SOLARIS was approved as a program. The Council confirmed full subscription to the General Support Technology Programme, Element-1, which requested funding for SOLARIS development.  The activities performed under Element 1 support maturing technologies, building components, creating engineering tools and developing test beds for ESA missions, from engineering prototype up to qualification.  Still to be determined: how much funding will be allocated by each member of the EU.

Then in October an article published in Science asks the question “Has a new dawn arrived for space-based solar power?” The authors bring to light what many advocates have already realized: that better technology and falling launch costs have revived interest in the technology.  Also in October, MIT Technology Review issued a report “Power Beaming Comes of Age”. Based on interviews with researchers, physicists, and senior executives of power beaming companies, the report evaluated the economic and environmental impact of wireless power transmission to flush out the challenges of making the technology reliable, effective and secure.

China announced in November that it plans to test space solar power technologies outside its Tiangong space station. Using the robotic arms attached to the station, they plan to evaluate on-orbit assembly techniques for a space-based solar power test facility which will eventually then orbit independently to verify solar energy collection and wireless power transmission. The China Academy of Space Technology has already articulated plans for development of their own space solar power system culminating in a 2 Gigawatt facility in geostationary orbit by 2050.

To cap off the year, aerospace engineer and founder of The Spacefaring Institute Mike Snead published a four-part series on evaluation of green energy alternatives including space solar power which he calls Astroelectricity. In the first part, he covers the history of humanity’s energy use and the dawn of fossil fuel use over the last century pointing out the fragility of the current system with respect to energy security. A gradual transition to fossil fuel free alternatives is needed to provide enough time for technology development and conversion over to green energy sources while not creating shocks to an economy based mostly on coal, oil and gas.

Next, nuclear power is addressed (and dismissed) as a green alternative with the next generation of smaller modular fission nuclear reactors currently under development. Due to waste heat challenges and nuclear weapons proliferation issues plus problems with scaling up enough of these power plants as base load supply to supplement intermittent wind and solar, this alternative is rejected as a viable green alternative. No mention is made of some the numerous fusion energy development activities in process or the promise of thorium molten salt reactors, so some readers may take issue with Snead’s position on this point.

In the third installment, if it is assumed that nuclear power is not a viable option, Snead examines to what extent wind and terrestrial based solar power has to be scaled up to replace fossil fuels in the latter part of this century given population growth and resulting energy needs. Not surprisingly, given the intermittent nature of wind and solar he finds these sources lacking, and they “… are not practicable options for America to go green.” Enter space solar power to fill the void.

In the last article in his series, Snead provides guidance for establishing a national energy security strategy for an orderly transition to green energy. He concludes that, “With America’s terrestrial options for going green not providing practicable solutions, the time for America to develop space solar power-generated astroelectricity has arrived. America now needs to pursue space solar power-generated astroelectricity to ensure that our children and grandchildren enjoy an orderly, prosperous transition to green energy.”

Finally, we close out the year with this: Northrop Grumman announced plans for an end to end space to ground demo flight in 2025 of their Space Solar Power Incremental Demonstrations and Research (SSPIDR) project funded by the Air Force Research Laboratory. SSP reported on the SSPIDR system previously. This development sets up a race between Japan, Virtus Solis (both mentioned above) and the U.S. government to be the first to beam power from space to the ground by the middle of this decade.

Plasma process for in situ production of air, fuel and fertilizer on Mars

Hubble Space Telescope image of Mars showing clouds in atmosphere near the poles and the extinct volcano Olympus Mons at right. The primary constituents of the Martian air are carbon dioxide (95%) and nitrogen (~3%). Credits: NASA

A new technology funded by ESA is under development in Belgium and Portugal that could produce breathable air, oxidizer for rocket fuel and nitrogen for fertilizer out of thin air on Mars. Using a high energy plasma, researchers at the University of Antwerp and the University of Lisbon published independent results that look promising as a source of oxygen for life support and propulsion, plus nitrogen oxides as fertilizer to grow crops.

Team Antwerp heated simulated Martian atmosphere with microwaves in a plasma chamber. The electrical energy cracked the carbon dioxide and nitrogen in the gas into highly reactive species generating oxygen which, in addition to creating breathable air and oxidizer for fuel, was combined with the nitrogen to create useful fertilizer.

The scientists in Lisbon used direct current to excite the gases into a plasma state, literally creating lightning in a bottle. This team focused only on the production of oxygen.

The efficiency of these processes is quite impressive. For example, when compared to the Mars Oxygen In Situ Resource Utilization Experiment (MOXIE) on NASA’s Perseverance rover, the Antwerp system uses the same input power, about 1kWh, but produces 47 g per hour which is about 30 times faster. MOXIE uses solar energy to electrochemically split carbon dioxide into oxygen ions and carbon monoxide, then isolates and recombines the oxygen ions into breathable air.

Image of the toaster-sized Mars Oxygen In Situ Resource Utilization Experiment (MOXIE) being installed on the Perseverance rover at the Jet Propulsion Laboratory prior to launch. Credit: NASA/JPL-Caltech

The research is in early days but has the potential for benefits on Earth too. The amount of energy needed to fix nitrogen in fertilizer for terrestrial crops is significant and releases considerable amounts of carbon dioxide to support worldwide agriculture. This plasma technology, if it can be commercialized, has the potential to reduce the carbon footprint of Earth-based fertilizer production. The fact that the process has duel-use provides a profit motive for development of the equipment and scaling up production, which could lead to improvements in efficiency and reduction in the mass for space applications.

We love ISRU technology that facilitates production of consumables using local resources at space destinations, thereby reducing the mass that needs to be transported to support space settlements and enabling them to become self-sustaining.

Progress on inflatable lunar habitats

Conceptual illustration of a Moon base composed of inflatable habitats near one of the lunar poles. Credits: ESA / Pneumocell

The European Space Agency (ESA) recently published a report on a design study of an inflatable lunar habitat. The work was done by Austrian based Pneumocell in response to an ESA Open Space Innovation Platform campaign. The concept utilizes ultralight prefabricated structures that would be delivered to the desired location, inflated and then covered with regolith for radiation protection and thermal insulation. The main components of the habitat are toroidal greenhouses that are fed natural sunlight via a rotating mirror system that follow the sun. Since the dwellings are located at one of the lunar poles, horizontal illumination is available for most of the lunar night. Power is provided by photovoltaic arrays attached to the mirror assemblies. During short periods of darkness power is provided by batteries or fuel cells.

Cutaway view of the inflatable lunar habitat. Credits: ESA / Pneumocell

The detailed system study worked out engineering details of the most challenging elements including life support, power sources, temperature control, radiation protection and more. The greenhouses would provide sustenance and an environmentally controlled life support system for two inhabitants recycling everything. The authors claim that “…it appears possible to create in the long term a closed system…” This remains to be validated.

Inflatable space habitats have many advantages over rigid modules including lower weight, packaging efficiency, modularity and psychological benefit to the inhabitants because after deployment, the interior living space is much larger for a given mass. Several organizations and individuals have already begun to investigate inflatable habitats for lunar applications. The Pneumocell study mentions ESA’s Moon Village SOM-Architects concept which is a hybrid rigid and partly inflatable structure. Also referenced is the Foster’s and Partners Lunar Outpost design which envisions a 3D printed dome shaped shell formed over an inflatable enclosure.

Foster and Partners Lunar Outpost constructed from a hybrid of 3D printed modules and an inflatable structure. Credits: Foster and Partners

SSP previously covered another hybrid lunar inflatable structure designed by Rohith Dronadula. This design combines a collapsible rigid framework with an inflatable dome, can be autonomously launched from Earth and deployed through telepresence.

Illustration of a hybrid lunar inflatable structure. Credits: Rohith Dronadula

The Pneumocell report concludes: “A logical continuation of this study would be to build a prototype on Earth, which can be used to investigate various details of the suggested components … ” Such an approach would be relatively inexpensive and could inform the future design of flight hardware.

Speaking of ground based prototypes, The Space Development Network has been exploring inflatable structures for habitats on the Moon for some time. Doug Plata, president of the nonprofit organization working to advance space development hopes to display an inflatable version of his InstaBase concept at BocaChica, Texas when SpaceX attempts its first orbital launch of Starship, hopefully within the a year or so. When comparing his design to Pneumocell’s, Plata says in an email to SSP, “One difference is that we have the modules directly attached to each other and so avoid the mass of those connecting corridors.”

Conceptual illustration of InstaBase – a fully inflatable lunar base capable of supporting an initial crew of eight. Credits: The Space Development Network

In reference to the greenhouse designs, Plata continues: “As for the GreenHabs, they have a pretty interesting design to take advantage of direct sunlight. We address the shielding conceptually by fully covering the GreenHabs and then use PV solar drapes and transport the electricity into the GreenHabs via wires. By converting sunlight to electricity to LEDs, more surface area of plants can be grown than the surface area of the solar panels powering them. This is due to the full spectrum of the sun being converted to only those frequencies that plants use.”

It is great to see such creativity and variety of designs for abodes on the Moon. When reliable transportation systems such as Starship blaze the trail, we will be ready with easily deployable, safe and voluminous habitats for lunar settlements.

Artist rendering of the interior of an inflatable toroidal greenhouse in a lunar habitat. Credits: Pneumocell

Crops in space: providing sustenance and life support for settlers

Roadmap for research and infrastructure development for growing crops in space for human sustenance and life support, from the ISS to Mars. Credits: Grace L. Douglas, Raymond M. Wheeler and Ralph F. Fritsche

Space settlement advocates know that we will have to take our biosphere with us to space to produce food, provide breathable air and recycle wastes. Completely closing the system, i.e. recycling everything is a huge technological challenge, especially on a small scale like what is planned for settlements in free space or on the surfaces of the Moon or Mars. Fortunately, there are plenty of raw materials in the solar system for in situ resource utilization so we can live off the land, so to speak, until our bioregenerative life support system efficiencies improve.

Early research into crop production in space has been performed on the ISS. But the road ahead for space agriculture in the context of life support systems needs careful planning to pave the way toward biologically self-sustaining space settlements. A team of scientists at NASA is working on a roadmap toward sustainability with a step-by-step approach to bioregenerative life support systems (BLSS) that will provide food and oxygen for astronauts during the space agency’s mission plans in the decades ahead. In a paper in the journal Sustainability they identify the current state of the art, resource limitations and where gaps remain in the technology while drawing parallels between ecosystems in space and on Earth, with benefits for both.

Simulation and modeling of BLSS concepts is important to predict their behavior and help inform actual hardware designs. A team at the University of Arizona performed a study recently analyzing the inputs and outputs of such a system to improve efficiencies and apply it to food production on Earth in areas challenged by resource limitations and food insecurity. Sustainable ecosystems for supporting humans on and off Earth have similar goals: minimizing growing space, water usage, energy needs and waste production while simultaneously maximizing crop yields. The team presented their findings in a paper presented at the 50th International Conference on Environmental Systems held last July. In the study, a model of an ecosystem was created consisting of various combinations of plants, mushrooms, insects, and fish to support a population of 8 people for 183 days with an analysis of total growing area, water requirements, energy consumption and total wastes produced. The study concluded that “In terms of resource consumption, the strategy of growing plants, mushrooms, and insects is the most resource-efficient approach.”

At the same conference, an update was provided on a Scalable, Interactive Model of an Off-World Community (SIMOC). SIMOC was described in a previous post on the Space Analog for the Moon and Mars (SAM) located at Biosphere 2 in Arizona. SIMOC is a platform for education meeting standards for student science curriculum. Pupils or citizen scientists can customize human habitats on Mars by selection of mission duration, crew size, food provisions as well as choosing types of plants, levels of energy production, etc.. Users gain an understanding of the complexity of a BLSS and the tradeoffs between mechanical and biological variables of life support for long duration space missions. There is much to be learned on the limitations and stability of closed biospheres, as discussed last year.

Image of Biosphere 2, a research facility to support the development of computer models that simulate the biological, physical and chemical processes to predict ecosystem stability. Credits: Biosphere 2 / University of Arizona

Across the Pond, our European friends at LIQUIFER Systems Group are working on greenhouses for the Moon and Mars derived from the EDEN ISS simulation facility in Antarctica.

A BLSS based on plant biology could be augmented with dark ecosystems, the food chain based on bacteria that are chemotrophic, i.e. deriving their energy from chemical reactions rather then photosynthesis, which could significantly reduce the inputs of energy and water.

A concept for a lunar farm called Lunar Agriculture, Farming for the Future was published in 2020 by an international team of 27 students participating in the Southern Hemisphere Space Studies Program at the International Space University.

Layout of a potential subsurface lunar farm. Credits: International Space University and University of South Australia

As a treat to cap off this post, a retired software engineer and farmer named Marshall Martin living in Oklahoma provided his perspective on crops in space on The Space Show recently. A frequent caller to the program, this was his first appearance as a guest where, like the NASA team mentioned earlier, he recommends a phased approach to space farming starting with small orbital facilities, testing inputs and outputs as we go, to ensure the economics pay off at each stage of our migration off Earth. He even envisions chickens and goats as sources of protein and milk, although the weight limitations for inclusion of these animals in space-based ecosystems may not be possible for quite some time. Its unlikely that cows will ever make it to space but cultured meat production is a real possibility for the carnivores among us which is being studied by ESA.

Cattle in the cargo bay of the Firefly-class transport spaceship Serenity. Cows probably won’t make it to space because of weight, volume and resource limitations but cultured meat is a real possibility. Image from the television series Firefly. Credits: Josh Whedon/ Mutant Enemy, Inc. in associations with Twentieth Century Fox Television

Finally, for those thinking long term of eventual settlement of the galaxy, there are even some people modeling life support systems for interstellar arks.

Image of the interior of a worldship habitat for interstellar travel. Credits: Michel Lamontagne / Principium, Issue 32, February 2021

Sustainable space commerce and settlement

Artist impression of a sustainable settlement on the Moon. Credits: ESA – CC BY-SA IGO 3.0

Dylan Taylor of Voyager Space Holdings recently wrote an article in The Space Review on sustainable space manufacturing. He makes a convincing case that long-duration space missions and eventual human expansion throughout the solar system will require radical changes in the way we design, manufacture, repair and maintain space assets to ensure longevity. In addition, the cost of lifting materials out of Earth’s deep gravity well will drive sustainable technologies such as additive manufacturing in space and in situ resource utilization to reduce the mass of materials needed to be launched off our planet to support space infrastructure. In-space recycling and reuse technologies will also be needed along with robotic manufacturing, self-reparability and eventually, self-replicating machines.

But there is more to the philosophy of sustainability and its impact on the future of space activities. According to the Secure World Foundation (SWF), sustainability is essential for “Ensuring that all humanity can continue to use outer space for peaceful purposes and socioeconomic benefit now and in the long term. This will require international cooperation, discussion, and agreements designed to ensure that outer space is safe, secure and peaceful.” Much of the discussion centers around the problem of orbital debris, radio frequency interference, and accidental or irresponsible actions by space actors. SWF is active in facilitating dialog among stakeholders and international cooperation.

The National Science and Technology Council released a report in January called the National Orbital Debris Research and Development Plan. To address the issue, there are several companies about to start operations in LEO to deal with the orbital debris or in-orbit servicing. Japan based Astroscale just launched a demonstration mission of their End-of-Life Services by Astroscale (ELSA) platform to prove the technology of capturing and deorbiting satellites that have reached their end of life or other inert orbital debris.

Image of the Astroscales ELSA-d mission showing the larger servicer spacecraft releasing and preparing to dock with a “client” in a series of technical demonstrations, proving the capability to find and dock with defunct satellites and other debris. Credits Astroscale.

Even financial services and investment houses like Morgan Stanley are pushing for sustainability to reduce the risks to potential benefits emerging from the Newspace economy such as remote sensing to support food security, greenhouse gas monitoring, and renewable energy not to mention internet access for billions of people.

Sustainable operations on the Moon are being studied by several groups as the impact of exploration and development of Earth’s natural satellite is considered. Lunar dust when kicked up by rocket exhaust plumes could create hazards to space actor’s assets as well as Apollo heritage sites. SWF, along with For All Moonkind, the Open Lunar Foundation, the MIT Space Exploration Initiative and Arizona State University have teamed up on a project called the Moon Dialogs to advance interdisciplinary lunar policy directions on the mitigation of the lunar dust problem and to shape governance and coordination mechanisms among stakeholders on the lunar surface. SSP’s take on lunar dust mitigation was covered last July.

These few examples just scratch the surface. NASA, ESA and the UN Office for Outer Space Affairs have initiatives to foster sustainability in space. Humanity will need a collaborative approach where public and private stakeholders work together to ensure that the infrastructure to support near term commercial activities in space and eventual space settlement is both durable and self-sustaining.

The long-term sustainability of space. Credits: ESA / UNOOSA

UK company aims to turn lunar soil into oxygen

Artist’s depiction of a future lunar base 3D printed from local materials. Credits: ESA/Foster + Partners

A British company called Metalysis as been funded by ESA to study their industrial-scale production of metals and alloys for application in a lunar environment. Metalysis has already demonstrated that they can extract 96% of the total oxygen content from ilmenite, a black iron-titanium oxide with a chemical composition of FeTiO3 found by Apollo astronauts to be abundant in lunar regolith. The process leaves a metallic powder alloy that can be used for in-situ 3D printing on the Moon.

In a press release last month, Metalysis states that “The project will provide an assessment to prepare and de-risk technology developments, focused towards oxygen production for propellants and life support consumables. The ability to extract oxygen on the moon is vital for future exploration and habitation, being essential for sustainable long duration activities in space. In-Situ Resource Utilisation (ISRU) will significantly reduce the payload mass that
would be needed to be launched from Earth.”

ESA’s Biorock experiment demonstrates microbe extraction of rare Earth elements from simulated regolith aboard ISS

ESA astronaut Luca Parmitano loads microbes into the Kubik centrifuge facility on the International Space Station. Credits: ESA

A research team at the University of Edinburgh in the UK has just published an analysis of data from an experiment on the International Space Station that could lead to “biomining” on Mars or an asteroid. Published in Nature Communications on November 10, Cockell, C.S., Santomartino, R., Finster, K. et al.* present experimental results demonstrating microbiological leaching of rare Earth elements from basalt rock, an analogue for much of the regolith material on the Moon and Mars. Called BioRock, the ESA sponsored experiment examined three species of microorganisms under variable gravity conditions in the Kubik centrifuge facility located in Europe’s Columbus module on the ISS.

This technology is a significant breakthrough for in situ resource utilization. By “living off the land” on the Moon, Mars or an asteroid, space settlers could have an available source of valuable materials used in electronic devices and many other high-technology applications. These rare Earth elements and the traditional heavy mining equipment needed to extract them would not have to be launched from Earth, significantly reducing transportation and processing costs. Positive results were found under Earth gravity, Mars gravity and microgravity conditions. The authors conclude that the experiment “…shows the efficacy of microbe–mineral interactions for advancing the establishment of a self-sustaining permanent human presence beyond the Earth and the technical means to do that.”

* BioRock study Authors: Charles S. CockellRosa SantomartinoKai FinsterAnnemiek C. WaajenLorna J. EadesRalf MoellerPetra RettbergFelix M. FuchsRob Van HoudtNatalie LeysIlse ConinxJason HattonLuca ParmitanoJutta KrauseAndrea KoehlerNicol CaplinLobke ZuijderduijnAlessandro MarianiStefano S. PellariFabrizio CarubiaGiacomo LucianiMichele BalsamoValfredo ZolesiNatasha NicholsonClaire-Marie LoudonJeannine Doswald-WinklerMagdalena HerováBernd RattenbacherJennifer WadsworthR. Craig Everroad & René Demets