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Interview with Mikhail Shubov: Guided self replicating factories, orbital fuel depots, hydrogen production on Mars and other visions for space settlement

Vintage 1980 artist depiction of a self replicating factory on the Moon. Credits: NASA

Earlier this year SSP covered self replicating factories for space settlement. An innovative paper on this topic with a simpler approach was submitted by Mikhail Shubov to ArXiv.org in August that shows how to accelerate efforts in this area.

A fully autonomous self replicating factory in space requires significant advancements in artificial intelligence, robotics, and other fields. Such facilities are mainly theoretical at this point and may not be feasible for many decades. But if humans could “guide” the operation remotely via computer control, a colony on the Moon could be started relatively soon.  This could be the proving ground for establishing such facilities on other worlds which Shubov believes could be set up on Mercury, Mars and in the Asteroid Belt eventually leading to exponential growth allowing humanity to expand out into the solar system and beyond.  He suggests that rather then using the usual definition of self-replication in which a factory would make a duplicate copy of itself, until this capability is realized, a better figure of merit would be the “doubling time”. This is how long it takes to double the facility’s mass, energy production, and machine production.

I reached out to Dr. Shubov about this article and discovered that he has been busy with a variety of scholarly papers on several technologies needed for space settlement. He agreed to a wide ranging interview via email about these topics and his vision of our future in space.

SSP: Thank you Dr. Shubov for taking the time for this interview.  With respect to your work on Guided Self Replicating Factories (GSRF), there are already companies developing semiautonomous robots for in situ resource utilization on other worlds.   OffWorld, Inc. states that “We envision millions of smart robots working under human supervision on and offworld, turning the inner solar system into a better, gentler, greener place for life and civilization.”  Their business model is focused on developing a robotics platform for mining and construction on Earth, then leveraging the technology for use in space.  Do you think this is a good approach to get started?

MS: Thank you Mr. John Jossy for taking interest in my work!

In my opinion, remotely guided robots will be very effective for construction of a colony on the Moon. These robots could be guided by thousands of remote operators on Earth. They would be linked to Earth’s Internet via Starlink which is already being deployed by Elon Musk via SpaceX. Starlink will consist of thousands of satellites linked by lasers and providing broadband Internet on Earth. About 1,646 satellites are already orbiting the Earth.

Hopefully, it would be possible to produce [an] Earth-Moon Internet Connection of about a Terabit per second. That would enable people on Earth to remotely operate hundreds of thousands of robots.

Using these robots on Asteroids and other planets of Solar System will be much more difficult due to low bandwidth and high delay of communication. For example, latency of communication between Earth and Mars is 4 to 21 minutes.

SSP: Obviously, establishing outposts on other worlds where astronauts could teleoperate robots to build a GSRF would eliminate the latency problem, which you address in your paper.

You’ve envisioned four elements of a GSRF: an electric power plant, a material production system (ore mining, beneficiation, smelting), an assembly system in which factory parts are shaped and fabricated, and a space transportation system.  With respect to the space transportation system you cover both launch vehicles and in-space propulsion systems.  The space transportation element of a GSRF, although vital for its implementation, seems to be an external part of the system.  In fact, you stated that “Initially, spaceships will be built on Earth. Fuel for refueling spaceships will be produced in space colonies from the beginning.”  So, when calculating the doubling time of a GSRF, we are not including the production of space transportation systems, correct?

MS: In my opinion, [the] space transportation system may become part of GSRF at later stages of development. How soon space transportation becomes a part of GSRF depends on the speed of development of different technologies.

If inexpensive space launch from Earth becomes available, then there will be less reliance on self-replication and more reliance on transportation of materials from Earth. In this case, space transportation system will not be part of GSRF for a long time.

If rapid growth of a Space Colony by utilization of in situ resources is possible, then many elements of space transportation system would be produced at the colony. In this case, [the] space transportation system will become a part of GSRF relatively soon.

SSP: You suggest that an important product produced by a GSRF in the Asteroid Belt would be platinum group metals to be delivered to Earth, and that they would help finance expansion of space colonization.  Some space resource experts, including John C. Lewis, believe that “…there is so vast a supply of platinum-group elements in the NEA [Near Earth Asteroids] … that exploiting even a tiny fraction of them would cause the market value to crash, bringing to an end the economic incentive to mine and import them.”  Some suggest the market for these precious metals may be in space not on Earth.  When you say “delivered to Earth” what markets were you envisioning to generate the profits needed to finance the GSRF?

MS: In my opinion the main applications of platinum group metals would be in industry. First, PGM are very important as chemical reaction catalysts. In particular, platinum is used in hydrogen fuel cells and iridium is a catalyst in electrolytic cells. It is likely that demand for platinum, iridium and other PGM will grow along with hydrogen economy. Second, platinum and palladium is used in glass fiber production.

Third, Iridium-coated rhenium rocket thrusters have outstanding performance and reusability. Rhenium is also used in jet engines. These thrusters will also provide a market for iridium and rhenium metals.

SSP: As the need for PGM grows exponentially in the future, especially with energy and battery production needs on Earth in the near future, the environmental impacts of mining these materials on Earth may be another reason to source these materials off world.

Mining water to produce hydrogen for rocket fuel is a theme throughout your writings.  In a paper submitted to the arXix.org server last month entitled Feasibility Study For Hydrogen Producing Colony on Mars, you propose that a technologically mature Martian factory could produce and deliver at least 1 million tons of liquid hydrogen per year to Low Earth Orbit.  Does placing a hydrogen production facility on Mars for fuel used in near-Earth space make sense from a delta-v perspective?  You acknowledge that initially it will be cheaper and easier to access the Moon’s polar ice to produce hydrogen.  But in the long term, Near Earth Asteroids (NEA) or even the Asteroid Belt are easier to access and they include CI Group carbonaceous chondrites which contain a high percentage (22%) of water.  Can you reconcile the economics of sourcing hydrogen on Mars over NEAs?

MS: Delivery of Martian hydrogen into the vicinity of Earth may be necessary only when the space transportation technology is relatively mature. In particular, as I mention in my work, Lunar ice caps contain between 48 million and 73 million tons of easily accessible hydrogen. Until at least 16 million tons of Lunar hydrogen is used, hydrogen from other sources would not be needed.

As I calculate in my work, delta-v for transporting hydrogen from Low Mars Orbit to LEO is 3.5 km/s accomplished by rocket engines plus about 3.2 km/s accomplished by aerobreaking. This would be economic if vast amounts of electric energy will be produced on Mars easier than on asteroids. An important and renewable resource on Mars is the heat sink in the form of dry ice. This may enable production of vast amounts of electric energy by nuclear power plants.

Even if delivery of hydrogen from Low Mars Orbit to Earth turns out to be economically infeasible, hydrogen depots in near-Mars deep space would still play a very important role in transportation to and from Asteroid Belt as well as [the] Outer Solar System.

SSP: Your first choice of a power source for the colony on Mars is an innovative heat engine utilizing dry ice harvested from the vast cold reservoirs at the planet’s polar caps. You suggest that the initial heat source for this sublimation engine be a nuclear reactor. Why not simply use the nuclear reactor to produce electricity? Nuclear reactors coupled to high efficiency Stirling engines for electricity generation like NASA’s Kilopower project have very high power density per unit weight and the technology will be relatively mature soon. Your second choices are solar and wind which are not as reliable as a nuclear power source, especially with reduced solar flux at Mars’s orbit and the problem caused by dust in the atmosphere. Why was a more mature nuclear power technology for direct electricity production not considered?

MS: Thank you.  As I understand now, a regular nuclear reactor with a heat engine using water or ammonia as a working fluid is the best choice for energy production on Mars.  Dry ice should only be used as a heat sink and not as working fluid.  Given the very low temperature and ambient pressure of Martian dry ice, it is likely that power plants will have thermal efficiency of at least 50%.

Almost all components of Martian power stations can be manufactured from in situ resources.  Only the reactors themselves and the nuclear fuel will have to be delivered from Earth.

SSP: A booming space transportation economy will need cryogenic fuel depots to store hydrogen for rocket fuel in strategic locations throughout the inner solar system.  You’ve got this covered in your recent paper Hydrogen Fuel Depot in Space.  Some start ups like Orbit Fab have already started work in this area, albeit on a smaller scale, and United Launch Alliance integrated cryogenic storage into their Cislunar-1000 plans a few years back, but this initiative seems to have slowed down due to delays in ULA’s next generation Vulcan launch vehicle.  In this paper you calculate the required energy to refrigerate hydrogen in one smaller (400 tons) and another larger (40,000 tons) depot.  In both cases, a sun shield is required to block sunlight to prevent boil off.  You don’t mention the method of power generation to provide energy for the refrigeration units.  Could the sun shield have a dual use function by incorporating photovoltaic solar cells on the sun facing side to generate electricity to power the refrigeration system?

Diagram depicting a cryogenic liquid hydrogen storage depot with 40,000 ton capacity. Credits: Mikhail Shubov

MS: Power for the refrigeration system will be provided by an array of solar cells placed on the sun shield.  As I mention in my work, the 400 ton depot requires 80 kW electric power for the refrigeration system, while the 40,000 ton depot requires 840 kW electric power.  This power can be easily provided by photovoltaic arrays.

SSP: SpaceX has proven what was once believed impossible: that rockets could be reused and that turnaround times and reliability could approach airline type operations.  Although we are not there yet, costs continue to come down.  In your paper entitled Feasibility Study For Multiply Reusable Space Launch System you calculate that with your proposed system in which the first two stages are reusable and the third stage engine can be returned from orbit, launch costs could be reduced to $300/kg.  Musk is claiming that with the projected long term flight cadence, eventually Starship costs could be as low as $10/kg.  Even if he is off by a factor of 10 that is still lower than your figure.  What advantages does your system offer over Starship? 

MS: The main advantage of the Multiply Reusable Space Launch System is the relatively light load placed on each stage. As I mention on p. 10, the first stage has delta-v of 2.6 km/s and the second stage has delta-v of 1.85 km/s. The engines have high fuel to oxidizer ratio and a low combustion chamber temperature of 2,100oC. These relatively light loads on the rocket airframes and engines should make these rockets multiply reusable similar to airliners. The launch system should be able to perform about 300 space deliveries per year.

Hopefully Elon Musk would succeed [in] reducing launch costs to at least $100 per kg. Unfortunately, many previous attempts at drastic reduction of launch costs did not succeed. Hence, we may not be sure of Starship’s success yet.

SSP: You state in several of your papers that:

“A civilization encompassing the whole Solar System would be able to support a population of 10 quadrillion people at material living standards vastly superior to those in USA 2020. Colonization of the Solar System will be an extraordinary important step for Humankind.”

Why do you think that colonization of the solar system is important for humanity and when do you think the first permanent settlement will be established on the Moon or in free space?  Here I use the National Space Society’s definition of a space settlement:

‘ “A space settlement” refers to a habitation in space or on a celestial body where families live on a permanent basis, and that engages in commercial activity which enables the settlement to grow over time, with the goal of becoming economically and biologically self-sustaining as a part of a larger network of space settlements. “Space settlement” refers to the creation of that larger network of space settlements. ‘

MS: In my opinion colonization of Solar System will bring unlimited resources and material prosperity to Humankind.   The human population itself will be able to grow by the factor of a million without putting a strain on the available resources.

As for the time-frame of establishment of human settlements on the Moon and outer space, I have both optimistic and pessimistic thoughts.  On one hand, Humankind already possesses technology needed to establish rapidly growing space settlements.  This means that Solar System colonization can start at any time. On the other hand, such technology already existed in 1970s.  This technology is discussed in Gerard K. O’Neill’s 1976 book “The High Frontier: Human Colonies in Space”.  Thus, space colonization can be indefinitely delayed by the lack of political will.  Hopefully space colonization will start sooner rather then later.

Credits: Gerard K. O’Neill / Space Studies Institute Press
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Saving Earth and opening the solar system with the nuclear rocket

The NERVA solid core nuclear rocket engine. Credits: NASA

James Dewar believes it is time to reconsider the solid core nuclear thermal rocket, like what was developed in the 1960s under the NASA’s Nuclear Engine for Rocket Vehicle Application (NERVA) Project, as a high thrust cargo vehicle for opening up the solar system and for solving problems here on Earth. A tall order, as he explained in his appearance on The Space Show (TSS) October 26, because nuclear propulsion within the atmosphere and close to the Earth was taken off the table by NASA over 60 years ago and research on nuclear rockets was put on ice after 1973 until recently. Dewar worked on nuclear policy at the Atomic Energy Commission and its successor agencies, the Energy Research and Development Administration and the Department of Energy. He has documented his views in a paper linked on TSS blog.

What is old could be new again. NERVA had a very light high power solid core reactor with Uranium 235 fuel in a graphite matrix creating nuclear fission to heat hydrogen to produce rocket thrust. The specific impulse (efficiency in conversion of fuel to thrust) of the first iteration of NERVA was about 825 seconds, or almost twice that of chemical rockets. More efficient versions were on the drawing board. The compact design (35×52-inch core) lends itself to low development costs and would be inexpensive to fabricate and operate. It has the potential to lower launch costs significantly and research could pick up where it left off nearly 50 years ago.

So why is NASA announcing development of new nuclear thermal propulsion systems for missions to Mars in the distant future? The reactor cores like those used in Project NERVA are known technologies that can it be adapted for other useful applications and it can be done safely on Earth. There could be a large niche market for energy production in remote rural areas such as Alaska or Canada, or supplementing base load utilities during power disruptions due to severe weather events. With their high operating temperatures, these reactors can replace fossil fuel power generation for manufacturing industries that require process heat such as steel/aluminum or chemical production, which cannot be powered efficiently by wind or solar energy. There may also be a cost advantage and environmental benefit to replacing carbon based fuels for powering maritime oceangoing vessels.

“Even the Greens may support it…What if a reestablished program included making a nuclear propelled 1000-foot tanker sized skimmer to rid the oceans of plastic?”

Additionally, a nuclear reactor of this type could service manufacturing centers in both space and on Earth. It could inexpensively launch satellites and provide power for environmental and solar weather stations to monitor and protect Earth’s health. Dewar even thinks that the solid core nuclear reactor could be used to address the growing global problem of industrial waste by melting it down to its chemical constituents and then separating out commercially valuable components from the actual waste prior to permanent disposal. The low launch costs of the nuclear rocket may actually make disposal of waste off Earth economically feasible. Whole clean industries could spring up around these process centers. So this type of reactor could address many national goals and objectives rather than just crewed missions to Mars or deep space.

But what about the elephant in the room? Safety, radiation and fear of all things “nuclear”? Would the public support ground based testing if a NERVA type solid core nuclear thermal rocket program were restarted? Dewar covers this in detail in his book The Nuclear Rocket, Making Our Planet Green, Peaceful and Prosperous. As reported by the EPA in 1974, “…It is concluded that off-site exposures or doses from nuclear rocket engine tests at [the] NRDS [Nuclear Rocket Development Station] have been below applicable guides.”

What about regular launches of a nuclear rocket in the Earth’s atmosphere? First, the launch range proposed would be in an isolated ocean area over water to eliminate the possibility of failure or impact in populated regions. Second, the nuclear core would be enclosed in a reentry vehicle type cocoon for safe recovery in the event of an accident. Third, the nuclear engine is envisioned as an upper stage and would not be “turned on” until boosted high in the stratosphere, thus emission of gamma rays and neutrons from the fission reaction would not be any different then the radiation already impinging on our atmosphere from cosmic and solar radiation.

“…the best way to banish fear is for citizens to profit from the program.”

There is also the potential for the U.S. and its citizens to profit from this venture. Dewar suggests a governance framework for creating a public/private corporation in which the private sector is in charge, but leases assets from NASA and DOE. The government would support the venture via isolated testing sites, providing technical advice, supplying the uranium fuel and security to guard against potential nuclear proliferation. The public/private partnership would be set up to incentivize citizen participation through stock purchases and distribution of dividends in addition to providing jobs and funding the missions.

“Another source of funding would exist beyond the government or private billionaires: the public now has access”

Dewar concludes his paper with an inspirational statement: “…a new space program emerges based on science, not emotion, one that maximizes the technology for terrestrial applications, one that neuters the rocket equations and democratizes the space program, allowing citizens to participate and profit, and one that ever integrates Earth into the Solar System.”

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Freedom Engineering in Space

A tongue-in-cheek Freedom Engineering poster encouraging space settlers to produce oxygen through plant growth as an alternative to dependency on centralized oxygen production facilities. Credits: Charles Cockell

At the 24th Annual International Mars Society Convention held October 14 – 17, Dr. Charles Cockell, professor of Astrobiology in the School of Physics and Astronomy at the University of Edinburgh, gave a talk on what he calls Freedom Engineering. His viewpoint was also published in a paper via the journal Space Policy in August of 2019. Cockell makes the case that due to the extreme constraints imposed by the laws of physics on living conditions in space settlements, freedom of movement will necessarily be restricted. Such conditions could be exploited by tyrannical governments to limit social, political and economic freedoms as well. To address these concerns Cockell suggests that colony designers utilize proactive engineering measures in planning off Earth communities to maximize liberty in the space environment. For example, rather then one centralized oxygen production facility or method that may be leveraged by a despot to control the population, it is suggested that settlements be designed with multiple facilities distributed widely and if possible, other types of oxygen production (e.g. greenhouses) be employed to minimize the chance of monopolization.

This engineering philosophy raised many questions among colleagues of mine so I reached out to Dr. Cockell for an interview via email to provide answers. He graciously agreed and I’m very grateful for his responses.

SSP: How is Freedom Engineering different from standard engineering practices of designing for redundancy to prevent single point failure?

CC: There is a strong overlap. For example, if you want redundancy, you multiply oxygen production. That would also be a desired objective to minimize the chances of monopolistic control over oxygen. So often the objectives are the same. However, I suggest that freedom engineering is a specific focus on engineering solutions that cannot be used to create coercive extraterrestrial regimes, which is not always the same as redundancy. For example, we might minimize the use of cameras and audio devices to monitor habitats for structural integrity, an objective consistent with general engineering demands, but potentially antithetical to human freedoms.

SSP: Since the added costs are significant and we may not be able to follow these practices initially, how do we get around the problems you mention after being on the Moon a decade or two? Wouldn’t the forces of tyranny have already won?

CC: Liberty is never cheap in resources and human effort. You can take a cost-cutting approach and hope that tyrannical regimes don’t take hold in a settlement or you can plan before hand to minimize their success, even if that involves more cost. However, as many freedom engineering solutions are compatible with redundancy, it is not necessarily the case that introducing measures like maximizing oxygen production and spacesuit manufacture motivated by considerations on liberty would add significantly to a cost already incurred by ensuring redundancy.

Liberty is never cheap in resources and human effort.

SSP: How do we avoid centralized control of transportation? Will we have two or more landing pads, several sets of rockets? – e.g., Musk, Bezos, and ULA?

CC: I would say that maximizing the number of entities with transportation capabilities is a good idea. Here too, we would want to achieve this for redundancy, but it would also reduce the chances of monopolization and the isolation of a settlement (particularly if leaving the settlement can only be achieved with one provider). This could also include multiplying the physical number of rocket launch and arrival points.

SSP: There are always non-redundant systems, which you acknowledge. At some level there are critical infrastructures that cannot be made redundant because then we get into an infinite loop. If a tyrannical power wanted to control everything on the Moon, for example, that is where they would focus their control. Can you comment?

CC: That’s true. It goes without saying that, as on Earth, a determined despot with enough support can find ways to take over a society. However, as the framers of the US Constitution understood, if you can introduce enough checks and balances you can make tyranny an outcome that requires many of those to fail. You reduce the risk. So by minimizing the number of single point controls in an extraterrestrial society you never eliminate the chances of tyranny, but you reduce the number of options open to those with tyrannical tendencies.

It goes without saying that, as on Earth, a determined despot with enough support can find ways to take over a society.

SSP: How would a tyrannical off-Earth settlement get its citizens when moving to such a settlement would seem like a terrible idea?

CC: It’s true that an overtly tyrannical settlement may eventually find it difficult to recruit people and might therefore fail. One might hope that this would be a feedback loop that would discourage tyranny in space. However, when building free government[s], it’s a good idea to assume the worse to achieve the best, i.e. assume that people will attempt to, and can, create a tyranny, and then build a system that minimizes this possibility. It’s also worth pointing out that once people are in a settlement, they will be physically isolated under some governance power. Just as it isn’t trivial to remove a tyranny on Earth that has a population corralled under it once it is established, it may not be easy to free a settlement once it has a population under its control. It is worthwhile to attempt to design societies that avoid this possibility from the beginning.

SSP: Would a space settlement economy with multiple competing companies providing essential needs such as life support, obviate the requirement for engineering redundancy since it would be more difficult for a tyrannical government to take over all the means of production?

CC: Yes, I think in many ways multiple competing companies is a form of redundancy – providing many conduits for production and minimizing single points of control or failure. Maximizing productive capacity is essential. I would mandate some basic level of oxygen production capability, for example, that any settlement must be capable of producing to keep people alive, and then try and stimulate a private market in fashionable oxygen machines of various kinds, different oxygen production methods etc. Of course, one should not be utopian. A coercive monopoly could still control a lot of this, but in general the more entities that produce vital resources, the more likely real choice can emerge in some form.

SSP: One reasonable measure that can be taken that doesn’t fall under normal engineering approaches is standardizing data transparency. It might make sense that it should be a matter of public record, and easily assessable, the records of who does what with vital resources and how activities that seriously impact human safety are managed. This can be done without compromising anyone’s intellectual property. The full light of day can be good protection especially when used proactively, and establishing such standards would head off the opportunity to wave things away as bias or smear campaigns. Open-source approaches to data are already a big thing for all the space agencies and may be the best course of action. Do you have an opinion on this philosophy?

CC: I think this is essential. The freedom engineering approach I suggest is just one mechanism for reducing coercive governance, but a free society is constructed from many other needs. In some of my previous papers I have discussed exactly this – the need for transparency in information about oxygen production, who is funding it, and how etc. A general culture of openness is necessary. There may be some novel approaches such electing members of the settlement by lot to take part in meetings to do with oxygen or water production, for instance, and write public reports. Corporations will find all this very annoying of course, but the wider culture of liberty will be enhanced by a very ‘leaky’ society with respect to information. Other essential things are a free press (even if that is just informal lunar or Martian newspapers), transparency in elections for running the settlement, and perhaps maximum terms on people involved in health and safety tasks to create fluidity in the network of officialdom that oversees the potentially large number of health and safety concerns with respect to radiation, dust, production of essential items.

Corporations will find all this very annoying of course, but the wider culture of liberty will be enhanced by a very ‘leaky’ society with respect to information.

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The emerging in-space manufacturing economy

Diagram depicting the market sectors of the nascent in-space economy. Credits: Erik Kulu / Factories in Space

Erik Kulu, a Senior Systems Engineer in the satellite industry, has a passion for emerging technologies…especially those in the in-space manufacturing field. He’s created the largest public database of companies active in the emerging in-space economy. Called Factories in Space, it tracks companies engaged in microgravity services, space resources, in-space transport services, the economies of LEO, cislunar space, the Moon and much more.

Kulu provides an overview of commercial microgravity applications for both terrestrial and in-space use. His listing and analysis of potential business ventures provides a comprehensive summary of unique profitable commodities manufactured in microgravity, including fiber optics, medical products, exotic materials and many more.

Breakdown of the in-space manufacturing sector of the space economy. Credits: Erik Kulu / Factories in Space

“This is the missing piece to speed up development for the exciting Star Trek-like future. I believe in-space manufacturing will be the kickstarter and foundation.”

In a recent industry survey examining the commercial landscape of space resources in 2021, Kulu renders a statistical breakdown of the currently evolving development stages of in-space manufacturing companies, levels of funding by market sector, timing of company founding and geographical location of the main players. His analysis shows a marked increase in the formation of companies from 2016 – 2018 dropping off over the last 3 years.

Prominent founding peak of space resource companies in 2018 with drop at end of the last decade. Credits: Erik Kulu / Factories in Space

I asked Kulu about what he thought caused the downward taper because it seemed to have started before the COVID-19 pandemic, and so was probably unrelated. He agreed, and offers this explanation:

“Primarily, I think the decline is a mix of following:

  1. There was a boom of some sorts, which has slowed down in terms of very new startups. Similar graphs [indicate the same trend] for nanosatellite, constellation and launcher companies. Funding boom is continuing though.
  2. As many of those space fields do not have obvious markets, some potential new actors might be in wait mode, because they want to see what happens financially and technically to existing companies.
  3. Startups could be in stealth mode or very early stage and as such I have not become aware of them yet. They will likely partially backfill.”

“While there was a decline, I forecast Starship and return to the Moon will kick off another wave in about 2-3 years.”

Kulu also tracks NewSpace commercial satellite constellations, small satellite rocket launchers and NewSpace funding options through his sister site NewSpace Index. But he doesn’t stop there. The world’s largest catalog of nanosatellites containing over 3200 nanosats and CubeSats can be found in his Nanosats database.

Learn more about how Erik Kulu got started tracking the in-space economy in this interview from earlier this year over on Filling Space. And be sure and tune in live to The Space Show next month when I cohost with David Livingston for his debut appearance, exact date to be determined. You can call the show and ask Erik questions directly. Check TSS Newsletter, updated weekly, for the show date once its set. This post will be updated when the schedule is finalized, so readers can check back here as well.

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Astrosettlement Development Strategy for human expansion into the solar system and beyond

Conceptual illustration of a Habitat Autonomous Locomotive Expandable (HALE) mobile self sustaining habitat under propulsion near a planetary destination. Credits: unknown artist via Thomas Matula

Dr. Thomas Matula, Professor at Sul Ross State University Uvalde, Texas, has developed an economically based strategy for space settlement. His plan addresses the deficiencies in many proposed visions of human expansion beyond earth, namely the missing economic and legal aspects needed for sustainable settlement of the solar system. Matula discussed his approach with David Livingston on The Space Show September 14 and in a paper entitled An Economic Based Strategy for Human Expansion into the Solar System attached to the show blog.

Astrosettlement Development Strategy (ADS) can be boiled down into a four step economically based roadmap for space settlement which could be started with minimal private funding. Each step would achieve economic success before moving on to the next level. The four levels are Earth based research, industrialization of the Moon, developing and settling the solar system and interstellar migration.

In the first step of Earth based research, Matula suggests developing a subscription based online role playing computer game with the purpose of creating a virtual simulation of a space settlement to model the social and economic aspects of communities beyond Earth. SSP has been following similar efforts already underway by Moonwards. Further research in this phase would look into space agriculture to understand the types of plants and dietary needs of space settlers and improving the efficiency of crop growth paving the way for self sustaining habitats. Matula has penned a different paper along these lines called The Role of Space Habitat Research in Providing Solutions to the Multiple Environmental Crises on Earth, also attached to the Space Show Blog, which could have duel use applications in addressing environmental problems on our home planet. There are already efforts underway in this arena with Controlled Environment Agriculture (CEA) utilizing greenhouse automation through the Internet of Things leading to reduction of water needs and an increase in crop yields.

“Developing the technology
to green the Solar System will also green the Earth for future generations”

Next on the roadmap is lunar industrialization. The focus of this step is to use robotics and in situ resource utilization to minimize the mass of materials lifted from Earth and to create lunar manufacturing capability in a cislunar economy that can be leveraged to build space based habitats for expansion into deep space.

Developing the solar system comes next. Once an economic foundation of industrialization of the Moon has been established, large mobile habitats can be built at the Earth-Moon Lagrange points L1 and L2. Called HALE, for Habitat Autonomous Locomotive Expandable, these are 1km wide self sustaining habitats with 1G artificial gravity capable of low energy transit throughout the solar system including out to the Kuiper Belt, where they can use the resources there to add to their size or build copies of themselves.

The final phase combines mobile free space settlement with advanced propulsion to develop the capability of expansion into the Oort cloud and on to the stars.

“…propulsion technology could advance to a point that would allow mobile space habitats designed for the Oort Cloud to be transformed into the first generational starships.”

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Where is the mother lode of space mining? The Moon or near-Earth asteroids?

Conceptual rendering of TransAstra Honey Bee Optical Mining Vehicle designed to harvest water from near-Earth asteroids: Credits: TransAstra Corporation

Advocates for mining the Moon and asteroids for resources to support a space based economy are split on where to get started. Should we mine the Moon’s polar regions or would near-Earth asteroids (NEAs) be easier to access?

Joel Sercel, founder and CEO of TransAstra Corporation, is positioning his company to be the provider of gas stations for the coming cislunar economy. In a presentation on asteroid mining to the 2020 Free Market Forum he makes the case (about 10 minutes into the talk) that from an energy perspective in terms of delta V, NEAs located in roughly the same orbital plane as the Earth’s orbit may be easier to access for mining volatiles and rare Earth elements.

Scott Dorrington of the University of New South Wales discusses an architecture of a near-Earth asteroid mining industry in a paper from the proceedings of the 67th International Astronautical Congress. He models a transportation network of various orbits in cislunar space for an economy based on asteroid water-ice as the primary commodity. The network is composed of mining spacecraft, processing plants, and space tugs moving materials between these orbits to service customers in geostationary orbit.

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Illustration depicting the layout of a transportation network in an asteroid mining industry in cislunar space. Credits: Scott Dorrington

On the other side of the argument, Kevin Cannon of the Colorado School of Mines in a post on his blog Planetary Intelligence lays out the case for the Moon being the best first choice. All of the useful elements available on asteroids are present on the Moon, and in some cases they are easier to access in terms of concentrated ore deposits. Although delta V requirements are higher to lift materials off the Moon, its much closer to where its needed in a cislunar economy. Trips out to a NEA would take a long time with current propulsion systems. In addition, he thinks mining NEAs would be an “operational nightmare” as most of these bodies are loose rubble piles of rocks and pebbles with irregular surfaces and very low gravity. This makes it hard to “land” on the asteroid, or difficult to capture and manipulate them. In an email I asked him if he was aware of SHEPHERD, a concept for gentle asteroid retrieval with a gas-filled enclosure which SSP covered in a previous post, but he had not heard of it. TransAstra’s Queen Bee asteroid mining spacecraft has a well thought out capture mechanism as well, although this concept like SHEPHERD are currently at very low technology readiness levels.

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SHEPHERD-Fuel variant harvesting ice from a NEA and condensing it into liquid water in storage tanks, then subsequent separation into hydrogen and oxygen (top). These tanks become the fuel source for a self-propelling tanker block (bottom) which can be delivered to a refueling rendezvous point in cislunar space. Credits: Concept depicted by: Bruce Damer and Ryan Norkus with key design partnership from Peter Jenniskens and Julian Nott

Cannon also makes the point that there is very little mass in the accessible NEAs when compared to the abundance of elements on the Moon.

“There’s more than enough material for near-term needs on the Moon too, and it’s far closer and easier to operate on.”

Finally, he believes that the Moon would be a better stepping stone to mining the asteroids then NEAs would be. This is because most of the mass in the asteroid belt is located in the largest bodies Ceres and Vesta. Operations for mining on these worlds would be more akin to activities on the Moon then on near-Earth asteroids.

Image of Vesta taken from the NASA Dawn spacecraft. Credit: NASA/JPL

What about moving a NEA to cislunar space as proposed by NASA under the Obama Administration with the Asteroid Redirect Mission? Paul Sutter, an astrophysicist at SUNY Stony Brook and the Flatiron Institute, investigates this scenario and suggests that at least the argument for these asteroids being too far away might be mitigated by this approach, although it would take a long time to retrieve them using solar electric propulsion, as recommended in the article. The trip time might be reduced with advanced propulsion such as nuclear thermal rockets currently under investigation by NASA.

It should be noted that TransAstra has both bases covered. They are working on innovations such as their Sun Flower™ power tower for harvesting water at the lunar poles as well as the company’s Apis™ family of spacecraft for asteroid capture and mining of NEAs.

Conceptual illustration of TransAstra’s Sun Flower™ power towers collecting solar energy above a permanently shadowed region on the Moon to provide power for ice mining operations. Credits: TransAstra Corp.

Update 28 August 2021: Take a deep dive into TransAstra’s future plans with Joel Sercel interviewed by Peter Garretson, Senior Fellow in Defense Studies at the American Foreign Policy Council podcast Space Strategy.

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The Pinwheel Magma Reactor: synthetic geology for ISRU

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Conceptual depiction of the Pinwheel Magma Reactor on a planetary surface in the foreground and in free space on a tether as shown in the inset. Credits: Kevin Cannon

How can space settlers harness useful resources that have not been concentrated into ore bodies like what takes place via geologic process on Earth over eons of time? Could we artificially speed up the process using synthetic geology? Kevin Cannon, a planetary geologist at the Colorado School of Mines (CSM), thinks it might be possible to unlock the periodic table in space to access a treasure trove of materials with an invention he calls the Pinwheel Magma Reactor. He has submitted a NASA Innovative Advanced Concepts proposal for the concept. The device is a essentially a centrifuge sitting on a planetary surface with a solar furnace reaction chamber spun at the end of its axis. In space, a free flying system could be connected by tether.

PMR chambers are positioned at the end of the axis of a centrifuge. Credits: Kevin Cannon

In a Twitter thread Cannon sets the table with a basic geology lesson explaining why mining on Earth is so different from what we will need in space. The Earth’s dynamic crustal processes, driven by fluid flow and plate tectonics over millions of years, exhibit a very different geology then that under which the Moon, Mars and asteroids evolved. The critical minerals that could be useful to support life and a thriving economy in space settlements are present in far lower concentrations in space then on Earth.

Current plans for ISRU infrastructure on the Moon and asteroids are only targeting a small set of elements like hydrogen, oxygen, carbon, silicon and iron (below, left).

Illustration of the periodic table showing currently targeted elements for ISRU on the left. On the right, the most mined elements on Earth (colored gold) and critical elements (orange) useful for an advanced society. Credits: Kevin Cannon

But an advanced society expanding out into the solar system would benefit from many critical minerals (above, right) that are not easily accessible because of their far lower concentrations. For example, energy production will need uranium and thorium, energy storage systems require lithium and electronics manufacturing is dependent on rare earths. So how to unlock the periodic table for these critical materials?

If we are to live off the land by harvesting useful materials to build and sustain space settlements we’ll need a totally revolutionary mining process. The PMR was designed with this in mind. The procedure begins by loading unprepared rocks or regolith into the chamber followed by heating via a solar furnace. Next, the chamber is spun up in the centrifuge where super gravity concentrates the desired minerals. Cannon believes that the PMR could also be used to extract water from regolith on the moon or asteroids.

“If hydrated asteroid material or icy regolith are put in at low temperatures, they’ll be separated by super-gravity and can be siphoned off.”

Of course the technology needs to be validated and flight hardware developed to determine if the PMR can be a tool to speed up the geological processes to concentrate useful materials for humans, who can then use them to synthetically propagate life in space. Cannon sums it up:

“Obviously a lot of work to be done to prove out the concept. But I think that a process flow of synthetic geology -> synthetic biology is the way to solve the concentration problem in space and enrich any element we want from the periodic table.”

Check out Cannon’s research page at The Cannon Group . He also blogs on space resources and development at Planetary Intelligence.

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Virtus Solis: Affordable Space Solar Power

Conceptual illustration of a Virtus Solis satellite array beaming power to central California (not to scale). Credits: Virtus Solis Technologies. NOTE: all images in this post are credited to Virtus Solis Technologies

Ever since I was in high school space solar power has been the holy grail of space advocates. I even wrote a report on the topic based on Peter Glaser’s vision in my high school physics class before Gerard K. O’Neill popularized the concept in The High Frontier leveraging it as the economic engine behind orbiting space settlements. But the technology was far from mature back then, and O’Neill knew back in 1976 the other main reason why after all these years space solar power has not been realized:

“If satellite solar power is an alternative as attractive as this discussion indicates, the question is, why is it not being supported and pushed in vigorous way? The answer can be summarized in one phrase: lift costs.” – Gerard K. O’Neill, The High Frontier

John Bucknell, CEO and Founder of Virtus Solis, the company behind the first design to cost space solar power system (SSPS), believes that recent technological advances, not the least of which are plummeting launch costs, will change all that.  He claims that his approach will be able to undercut fossil fuel power plants on price.  He recently appeared on The Space Show (TSS) with Dr. David Livingston discussing his new venture.  SSP reached out to him for an exclusive interview and a deep dive on his approach, the market for space solar power and its impact on space development.

SSP: Technological advancements of all the elements of a space solar power system have gradually matured over the last few decades such that size, mass and costs have been reduced to the point where there are now experiments in space to demonstrate feasibility.  For example, SSP has been following the first test of the Naval Research Laboratory’s Photovoltaic Radio-frequency Antenna Module (PRAM) aboard the Air Force’s X37 Orbital test vehicle.  Caltech’s Space-based Solar Power Project (SSPP) has been working on a tile configuration that combines the photovoltaic (PV) solar power collection, conversion to radio frequency power, and transmission through antennas in a compact module.  According to your write-up in Next Big Future on a talk given to the Power Satellite Economics Group by the SSPP project manager Dr. Rich Madonna, they plan a flight demonstration of the tile configuration this December.  The Air Force Research Laboratory’s Space Solar Power Incremental Demonstrations and Research (SSPIDR) project also plans a flight demonstration later this year with an as yet unannounced configuration.  Which configuration of this critical element (PRAM or tile) do you think is the most cost effective and can you say if your system will be using one of these two configurations or some other alternative?

Bucknell: There is a lot of merit to the tile configuration as it shares much of it’s manufacturing process with existing printed circuit board (PCB) construction techniques. The PRAM itself is a version of the tile, but as it was Dr. Paul Jaffe’s doctoral dissertation prototype (from 2013) it did not use PCB techniques and should not be considered an intended SSPS architecture. Details of Caltech’s latest design aren’t released, but it appears they intend to deploy a flexible membrane version of the tile to allow automated deployment. Similar story with SSPIDR. As space solar power is a manufacturing play as much as anything, you would choose known large scale manufacturing techniques as your basis for scaling if you intend earth-based manufacturing – which we do. So yes, we are planning a version of the tile configuration.

SSP: You’ve said that the TRL levels of most of the elements of an SSPS are fairly mature but that the wireless power transmission of a full up phased array antenna from space to Earth is at TRL 5-6.  The Air Force Research Laboratory (AFRL) plans a prototype flight as the next phase of the SSPIDR project with demonstration of wireless power transmission from LEO to Earth in 2023.  What is your timeline for launching a demo and will it beat the Air Force?

Bucknell: Our timescales are similar for a demonstrator, but I suspect the objectives of a military-focused solution would be different than ours.  We would plan a LEO technology demonstrator meeting most of the performance metrics required for a MEO commercial deployment.

SSP: Your solution is composed of mass produced, factory-built components including satellites that will be launched repeatedly as needed to build out orbital arrays.  Will multiple satellites be launched in one payload or will each module be launched on its own?  What is the mass upper limit of each payload and how many launches are needed for the entire system?

Bucknell: We intend a modular solution, such that very few variants are required for all missions. A good performance metric for a SSP satellite would be W/kg – and we believe we can approach 500 W/kg for our satellites (Caltech has demonstrated over 1000 W/kg for their solution). With known launchers and their payloads a 100MW system would take three launches of a Starship, with less capable launchers requiring many more. Since launch cost is inversely related to payload mass, we expect Starship to be the least expensive option although having a competitive launch landscape will help that aspect of the economics with forthcoming launchers from Relativity Space, Astra and Rocket Lab being possibilities.

SSP: The way you have described the Virtus Solis system, it sounds like once your elements are in orbit, additional steps are needed to coordinate them into a functional collector/phased array. Presumably, this requires some sort of on-orbit assembly or automated in-space maneuvering of the modules into the final configuration. I know you are in stealth mode at this point, but can you reveal any details about how the system all comes together?

Bucknell: An on-orbit robotic assembly step is necessary, although the robotic sophistication required is intentionally very low.

SSP: Your system is composed of a constellation of collection/transmitter units placed in multiple elliptical Molniya sun-synchronous orbits with perigee 800-km, apogee 35,000-km and high inclination (e.g. > 60 degrees).  I understand this allows the PV collectors to always face the sun while the microwave array can transmit to the target area without the need for physical steering, which simplifies the design of the spacecraft.  Upon launch, will the elements be placed in this orbit right away or will they be “assembled” in LEO and then moved to the destination orbit.  Do the individual elements or each system assembly as a whole have on-board propulsion?

Bucknell: The concept of operations is array assembly in final orbit, mostly to avoid debris raising from lower orbits.

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

SSP: The primary objective of the AFRL SSPIDR project is delivery of power to forward deployed expeditionary forces on Earth which would assure energy supply with reduced risk and lower logistical costs.  It sounds like your system would not work for this application given the need for 2-km diameter rectenna.  Could this potential market be a point of entry for your system if it were scaled down or reconfigured in some way?

Bucknell: Wireless Power Transmission (WPT) at orbital to surface distances suffer from diffraction limits, which is true for optics of all kinds.  It is not physically possible to place all the power on a small receiver, and therefore the military will likely accept that constraint.  As a commercial enterprise, we could not afford to not collect the expensively-acquired and transmitted energy to the ground station. There are also health and safety considerations for higher intensity WPT systems – ours cannot exceed the intensity of sunlight for example, and therefore is not weaponizable.

SSP: You said on TSS that your strategy would, at least initially, bypass utilities in favor of independent power producers.  What criteria is required to qualify your system for adoption by these organizations?  You mentioned you have already started discussions with one such group.  Can you provide any further details about how they would incorporate an SSPS into their existing assets? 

Bucknell: One of the key features of space solar power is on-demand dispatchability.  Grid-tied space solar power generation has the benefit of being able to bid into existing grids when generation is needed and task the asset to other sites when demand is low.  This all assumes that penetration will be gradual, but some potential customers might desire baseload capacity in which case there is not as much need for dispatchability.  Each customer’s optimal generation profile is likely to be unique so it is preferable to attempt to match that with a flexible system.

Conceptual illustration of a 1GW Virtus Solis rectenna array next to Topaz Solar Farm of 550MW capacity in San Luis Obispo County, California

SSP: Other companies have alternative SSPS designs planned for this market.  For example, SPS – ALPHA by Solar Space Technologies in Australia and CASSIOPeiA by International Electric Company in the UK. How does Virtus Solis differentiate itself from the competition?

Bucknell: From a product perspective, we are able to provide baseload capacity at far lower cost. Also, we intentionally selected orbits to not only reduce costs but to induce sharing of the orbital assets across the globe such that this is not a solution just for one country or region.

SSP: How big is the likely commercial market for your product/services going to be by the time you are ready to start commercial operations?  Can you share some of your assumptions and how they are derived?

Bucknell: Recent data indicates that electrical generation infrastructure worldwide is about $1.5T annually.  If you add fossil fuel prospecting, it is $3.5T.  Total worldwide generation market size is about $8T.  All of this is derived from BP’s “Statistical Review of World Energy – June 2018” and the report from the International Energy Agency “World Energy Investment 2018”

SSP: For your company to start operations, what total funding will be required, and will it come from a combination of government and private sources, or will you be securing funding only from private investors? 

Bucknell: As a startup, especially in hardware, funding comes from where you can get it.  To date no governmental funding opportunities have matched our technology, but that might change.  Our early raise has been from angel investors and venture capital firms.  Over the course of the research and development efforts, we expect demand for capital will be below $100M over the next several years but accurately forecasting the future is challenging.  We would note this level of required investment is far below our competition.

SSP: For hiring your management team, since this business is not mature, what analogous industries would you be looking at to recruit top talent?

Bucknell: Everything in our systems exist today elsewhere.  The wireless data industry (5G for example) has the tools and experience for developing radio frequency antennas and associated broadcast hardware.  The automotive industry has extensive experience with manufacturing electronics at low cost in high volumes, including power and control electronics.  Controls software engineering is a large field in aerospace and automotive, but in a large distributed system like ours the controls software will extend far beyond guidance, navigation and control (GNC).

SSP: O’Neill envisioned the production of SSPSs as the market driver for space settlements, in addition to replication of more space colonies.  This approach seems to have gathered less steam over the years as economics, technological improvements, and safety concerns have taken people out of the equation to build SSPSs in space.  In a recent article in the German online publication 1E9 Magazine you talked about SSPSs being useful for settlements on the Moon and Mars.  What role do you see them playing in free space settlements and could they still help realize O’Neill’s vision?

Bucknell: We stand at a cross-roads for in-space infrastructure.  For the first time access to space costs look to be low enough to make viable commercial reasons to deploy large amounts of infrastructure into cislunar space and beyond.  To date the infrastructure beyond earth observation and telecom has been deployed to mostly satisfy nation-state needs for science unable to be performed anywhere else as well as exploration missions (also a form of science).  However, there has to be a strong pull/demand to spur the construction of access to space hardware (heavy lift rockets) that consequently lowers the cost further through economies of scale.  As I described in my Space Show interview there are only a few commercial in-space businesses that are viable with today’s launch costs.  We have had telecom for a long time, followed closely by military and then commercial earth observation.  Now we have a large constellation of “internet of space”.  Even with those applications, there is not a large pull to scale reusable launch vehicle production – as reusability is counter-productive for economies of scale.  A large, self-supporting in-space infrastructure would be needed to bootstrap launch production sufficiently to self-fulfil low cost access to space – Space Solar Power is that infrastructure.  Space tourism, asteroid mining and others do not have scale nor potential lofted mass to scale the launch market adequately.  In that way, O’Neill’s vision is right – and the follow-on markets can leverage the largely paid-for launch infrastructure to make themselves viable.  Space solar power will be the enabler for humanity to live and work off-Earth, and Virtus Solis is leading the way.

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Enabling a multiplanetary civilization with photonic laser thrusters

Illustration of photonic laser thruster infrastructure for in-space transportation in cislunar space. Credits: Young K. Bae

Y.K. Bae Corp is on the verge of testing a revolutionary photonic laser thruster (PLT) that could be a game changer for in space propulsion and interplanetary travel. Founder and Chief Scientist Young K. Bae Ph.D described the technology in a recent Future In-Space Operations (FISO) Telecon presentation. The secret is generating thrust through photon pressure of a recycled laser beam enabling high energy to thrust efficiency without onboard propellant. Y.K. Bae Corp’s Continuous-Operation laser thruster or PLT-C is capable of delivering continuous thrust for long periods of time (e.g. days – years). The crew/payload section of the craft contains no power supplies, fuel or rocket engines. A power source is needed at the destination to generate a velocity reversal and stopping beam.

Dr. Bae believes an in-space “photonic railway” using this technology could open the solar system to commercialization and laid out a timeline for development of the photonic laser thruster. He believes that a 1 Newton (N) thrust PLT demonstration on the ISS could be accomplished within 3 years, a 50-N thrust PLT suborbital lunar launch is possible within 10 years, transits to the Moon can be done within 20 years and trips to Mars/Asteroids are projected to be in the 30 – 40 year timeframe.

When scaled up, super high ∆v can be achieved using the PLT. With a total electric laser power of 1000MW, travel times from the Earth to Mars could be achieved in less then 20 days for a 1-ton ship with 50% payload. From Mars out to Jupiter, a trip would take about 45 days for a craft with the same mass. The PLT spacecraft could be the main mode of rapid in-space transportation for humans and high price or lighter commodities after conventional thrusters (e.g. chemical rockets) establish the initial infrastructure and continue as the transportation choice for low cost or heavier payloads.

Illustration of a photonic railway using PLT infrastructure for in-space propulsion established at (from right to left, not to scale) Earth, Mars, Jupiter, Pluto and beyond. Credits: Young K. Bae.

Y.K. Bae Corp has demonstrated the photonic laser thruster technology in the lab. Check out their cubesat demo video.

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Update on SHEPHERD, an innovative spacecraft architecture for asteroid capture, mobilization and resource extraction

Artist renderings of an autonomous pneumatic handling system using SHEPHERD technology. An asteroid is first carefully enclosed in a touchless manner within a sealed fabric envelope, de-spun and de-tumbled through friction with an introduced controlling gas, then driven by continuous gas flow to introduce delta-V and deliver the asteroid to a target destination. Chemical and thermal interaction between the introduced atmosphere and the asteroid will permit fuel and water extraction, 3D electroforming of parts from metal sources and the creation of in-space biospheres to feed large habitats. Concept depicted by: Bruce Damer and Ryan Norkus with key design partnership from Peter Jenniskens and Julian Nott. Note: all of the illustrations in this post are credited as above unless otherwise indicated

The SHEPHERD concept for gentle asteroid retrieval with a gas-filled enclosure, an SSP favorite open source technology, has been covered in a previous post.  Dr. Bruce Damer, one of the coinventors of the system, recently appeared on SpaceWatch.Global’s Space Café podcast where he revisited this promising technology for capturing asteroids, mobilizing them and extracting key materials to support space settlement (which can be found near the end of the recording).  SHEPHERD could solve the three main sourcing problems of sustainable spaceflight and habitation: harvesting volatiles, building materials, and sources of food.  Dr. Damer has also been busy with his (and UCSC Prof. David Deamer’s) Hot Spring Hypothesis, a testable theory regarding the place and mechanism of the life’s origins on the Earth, which was the main focus of the podcast.  In fact, the arc of his career has tied these two endeavors together in interesting ways.  SSP reached out to Dr. Damer for an exclusive interview via email on these groundbreaking topics.

SSP: Dr. Damer, thank you so much for taking the time to answer my questions about SHEPHERD.  I’ve been excited and intrigued with the technology ever since I saw the initial paper and your 2015 TEDx talk.  Can you give our readers an overview of the concept?

Damer: The goal for SHEPHERD is to provide a universal technology to open the solar system to sustainable spaceflight and beyond that, to large scale human colonization (see figures and explanations for Fuel, Miner and Bio variants below). Enclosing an asteroid (or Near-Earth Object-NEO) within a fabric membrane and introducing a controlling gas would turn that asteroid into a “small world”. The temperature of the gas, its chemical composition and gas pressure forces set up within it can enable multiple in-situ resource utilization (ISRU) scenarios. Initially, the extraction of water and other volatiles from icy NEOs could provide fueling stations with deliveries throughout the solar system. Next, the use of the Mond-process carbonyl gas extraction from high-metallic NEOs can provide electroform 3D printing of large parts in space for construction of habitats. Lastly, melting the ice content of a NEO to a liquid phase surrounding its rocky core enables the introduction of microbes, algae and even some aquatic animals into a biosphere, a mini-Earth terrarium sustained in space. This one invention could provide many of the elements necessary for sustainable spaceflight but also for the construction and support of in-space and surface-located planetary and lunar habitats for thousands or millions of inhabitants. Co-inventor of the design, Dr. Peter Jenniskens at the SETI Institute, calls this the “sailing ship for space” harkening back to how his Dutch ancestors helped open the Earth to commerce centuries ago.

SHEPHERD-Fuel variant with volatiles such as water ice sublimating from the NEO into a warming gas, the resulting water vapor pumped down and condensed into liquids in storage tanks and then separated into hydrogen and oxygen. These tanks become the fuel source for a self-propelling tanker block which can be delivered to a refueling rendezvous point such as Earth cislunar space or Mars orbit
SHEPHERD-Miner version with an introduced carbonyl gas and an electric field dipole drawing off ions from a metallic NEO and layering them on a mandrel (shown on the left) to create a precision 3D part such as blocks, beams or tanks for space habitat construction
SHEPHERD-Bio variant sustaining a liquid biosphere around the rocky core of a NEO, with a lit interior and boom to introduce and extract organic materials. A balance of microbes, algae, and even small aquatic animals could maintain this small world, a “terrarium in space” to support large populations in habitats and at surface colonies
SHEPHERD-Fuel variant in Mars orbit or at some distance away showing the delivery of re-fillable tanker block sections to a Mars mission, the nearly empty block propelling itself for refilling. In this way ample fuel is provided in-situ prior to the craft arriving at Mars, with mission lander fuels, water for human consumption, shielding and return propellant provided in orbit in advance without having to extract volatiles from the Mars atmosphere or regolith
Vision of SHEPHERD Miner and Bio variants supporting a large habitat in LEO with the mantra of: “built in space, and fed in space”

SSP: Have there been any developments or updates to the concept since the initial TEDx talk and NewSpace Journal paper which both came out in 2015?

Damer: Back then we thought that no company or government had the will or capability to invest in such an opportunity, but this is now changing. The roaring success of NewSpace ventures such as SpaceX and their dual award of NASA’s Artemis Program returning humans to the moon based on reusable crewed launches and their recent successful low altitude testing rounds for Starship, has totally changed the space landscape of the near future. Jeff Bezos’ vision for megastructures in space based on the O’Neill colonies of the 1970s would require substantial asteroid resourcing. Elon Musk’s vision for large surface colonies on Mars would be equally well supported by simple, automated space based ISRU which overcomes substantial mining and manufacturing hazards attempting to process bulk materials on the surface of Mars or the moon. In addition, Bigelow’s success with inflatables, China’s surging space program with a new crewed station and rovers on the moon and Mars, all point to much more traffic and demand, especially for fueling depots, as early as the mid-2030s. Reducing the cost of lifting heavy and bulky materials from Earth may never be competitive to extraction, electroforming and farming in space with low-cost delivery directly to points of demand.

Earlier this year I determined that the time was right to place our invention out into the field again and seek partners to join in a development roadmap that will provide a solid financial and technical ladder for SHEPHERD’s maturation.

At a NASA/SETI meeting in January 2019 I was discussing SHEPHERD with members of the Luxembourg Space Agency and was overheard by space entrepreneur Carlos Calva. He approached me and offered that he would work with me to make SHEPHERD into a business. Subsequent meetings at SETI with my co-designer Peter Jenniskens (Julian Nott had died tragically in a ballooning accident) gave us early insights into SHEPHERD’s developmental timeline.

In that spring of 2019 Carlos and I engaged in a rapid-fire series of meetings developing a short-term cash business model for SHEPHERD which would provide a financial lever for the technology. Capturing, moving, and extracting resources from asteroids is a longer-term (15+ years) play, with no immediately apparent buyer for the first potential products: volatiles for propulsive fuel, air, water, and other crew consumables. Elon Musk and SpaceX might reach a point in this decade when they would buy a futures contract for hundreds, or thousands of tons of water and fuel delivered into Earth and Mars orbits sometime in the 2030s. Jeff Bezos may also want to finance the development of SHEPHERD as a technology for delivery of resources to build space habitats much as he has with Amazon’s funding of drone and other robotic fulfillment innovations.

But how to prove SHEPHERD as a technology and then sustain it as a business for long enough to be ready for either of these clients? We settled on two emerging market opportunities: 1) satellite servicing and decommissioning, and 2) hazardous debris removal and deorbiting. Both are potential cash businesses that could provide us achievable milestones to support the multiple investment rounds required. Satellite servicing and debris removal or de-risking is an urgent unmet market need for both governments and commercial operators worldwide. Along with the CubeSat revolution, SpaceX’s reusable launch platform and Bigelow Aerospace’s success with the inflatable Genesis and BEAM module on the ISS, many core technologies were maturing.

Making SHEPHERD into a viable sailing ship for space will not be without its challenges. Designing and flying a fabric enclosure which can open, admit an object (a satellite, a chunk of debris, or a space rock) and then closing it tight, sealing it well enough to fill it with a controlling gas was a major technical challenge which NASA identified  in their review of our 2014 Broad Agency Announcement proposal for the asteroid redirect program (since cancelled). The tried-and-true way to make a new space system work reliably is to build scale models, test them to failure, and test them again.

SSP: You mentioned that some of the capabilities of the system could be tested in LEO with CubeSats. Since the technology is open source, has anyone reached out to you to develop hardware for such an experiment? What would be tested and how?

Damer: Carlos and I made a bee-line for the world-renowned annual CubeSat Developer Conference meeting at Cal State San Luis Obispo in April of 2019 where we were able to interact with many of the leading thinkers and solution providers in the CubeSat industry. We devised a back-of-an-envelope LEO test vehicle flight series and made some key contacts. For a small investment (2-4 million USD), an effective six test flight series with a 4U CubeSat would first deploy a gas filled bag into which we could release a target object (such as a real meteorite which would be returned to space). The images below depict this scenario. Later flights in the series could have the target released to space and then the CubeSat would match orbits, track, enclose and seal the object into the enclosure. Key for any test is the ability to manage the object within the enclosure such that it does not contact the fabric. This would not be an issue for our small CubeSat, but it would be a potentially catastrophic encounter for a satellite or NEO. The key to safety (SHEPHERD stands for Secure Handling through Enclosure of Planetesimals Headed for Earth-Moon Retrograde Delivery) is that the system is touchless. In the image below we see gas jets firing to move the object toward and hold it in the center of the enclosure.

SHEP Cube test vehicle
Inflation of bag enclosure using controlling gas, introduced target object (perhaps a meteorite returned to space)
Management of target object position with gas jets
Lit interior showing target centered safely in the enclosure

All of this early effort to build and fly the CubeSat missions would mature our IP including: tracking, gas fluid dynamics for handling and enclosure deployment and sealing. We could then value the company and seek a round of investment from governmental or commercial partners in the satellite servicing and debris removal markets.

SSP: How do you foresee these two potential near term commercial applications generating sufficient revenue to “pay the way” for SHEPHERD to achieve its long-term goals?

A much larger SHEPHERD version with an enclosure for capture and servicing of a high value large satellite. Servicing could either be carried out with a robotic bay or by astronaut mechanics flying on SpaceX Dragon, who enter through an airlock and can breathe a low-pressure Earth atmosphere negating the need for bulky EVA/space suits

Damer: Paying the way for SHEPHERD could come from a mixture of satellite servicing (expensive “big birds” for the US DOD or communication satellite operators), orbit graveyarding (for GEO, or de-orbiting from LEO), and of course mitigation of dangerous space debris to head off Humanity’s disastrous  encounter with the “Kessler syndrome” as depicted in the movie Gravity. In-space satellite servicing via robotic spacecraft is problematic, requiring very high-risk grappling procedures between vehicles which have no built-in standard grappling mechanism. SHEPHERD provides a gas-based “pneumatic” way to safely envelop and control spacecraft without hard contact. Early computational studies at the SETI institute in 2014 established that a shape model of multi-ton asteroid 2008 TC3 could be de-tumbled and de-spun in less than 24 hours if the object was interacting within a gas at 10% Earth atmosphere pressure. The friction of the satellite or chunk of debris with the gas will bring it to a standstill, then gas jets can be used to rotate and position the enclosed spacecraft for servicing. Imparting a continuous driving force onto the craft using these same jets can create sufficient delta-V to change its orbit. Such safe handling and mobilization of objects in space is key to a whole range of future space operations. The irregularity of satellite shapes (including long booms or antennae) presents fewer challenges to SHEPHERD’s scale and size-independent gas handling system than they would to a robotic or crewed “jet pack” style EVA servicing as we saw with the Space Shuttle’s Hubble servicing missions.

If a satellite servicing, extension of life, or safe decommissioning capability were clearly on the horizon, supporters of international treaties and reinsurance companies could create guaranties, service contracts and insurance instruments which would finance a first generation of SHEPHERD vehicles.

SSP: What do you see as the full vision for the sustainable space architecture which SHEPHERD could enable?

A full vision of the architecture enabled by SHPHERD supporting near-Earth habitats, interplanetary missions, and a class of continuously cycling robotic and crewed spacecraft. Cycling visits of SHEPHERD ISRU supply depots could capture, relocate and extract from asteroids of all sizes and compositions. Eventually a mature SHEPHERD architecture could scale up enclosure sizes to provide the Earth a comprehensive planetary protection shield from larger NEO impact hazards

Damer: The image above depicts the enabling of SHEPHERD-derived spacecraft and processing facilities to support both near Earth space stations and larger megastructure colonies, robotic and human exploration of the inner solar system and beyond. I envision the SHEPHERD business being most akin to the mining industry I was raised around in British Columbia and as depicted in the Sci Fi series The Expanse. Some companies would fly prospecting (and orbit determination) missions to NEO targets, file claims and then sell them on to development companies. Those companies would license or build SHEPHERD-class spacecraft financed through contracts for future deliveries of commodities to companies and governments. Buyers would eventually acquire the risk-taking development companies and leverage them to support much larger projects such as space settlement megastructures or to supply Mars surface colony operations. Over time, scaling of the SHEPHERD system enclosure sizes would permit the safe handling and redirection of Earth-threatening asteroids giving us all a planetary protection shield. A great deal of Astrobiology science could also be supported such as the delivery of a pristine carbonaceous asteroid to Lunar orbit (see below) for astronaut geologists to sample. These samples might give us clues as to how life began on the Earth through the delivery of abundant organics from asteroids like this.

Release of pristine asteroid into Lunar orbit to support sampling by Astrobiologists looking for clues to life’s origins on the Earth, four billion years ago

SSP: What are the next steps for SHEPHERD?

Damer: The COVID-19 pandemic caused a pause on SHEPHERD’s development both as an engineering concept and a business. When I was invited to appear on the Space Café podcast in April (of 2021), I decided to bring it up again to gauge public interest and bring it to leaders in New Space. This interview with you is the next step in developing that interest, calling forward a development team. What I am also seeking is critical input from the community on the concept, leadership in research, and the formation of a company or university research program with financial support for the early on-ground computational and test-article studies leading up to CubeSat flights.

I specifically “open sourced” the basic concept of SHEPHERD on behalf of the three co-inventors in my 2015 TEDx talk, but IP developed by one or more implementers of this core concept can provide them and their investors with protectable value. The seal closure will be one key patentable innovation. Together with a team of keen and willing supporters including myself and Carlos, we produced a pitch deck which was first premiered at the Space Resources Roundtable held at the Colorado School of Mines in May of 2019. This deck concisely lays out the initial cash business in satellite servicing and debris removal and the engineering we have done around the CubeSat and larger variants. Carlos is back at work on the key steps of recruiting engineering leadership and funding for the ground-based development. I am open to inquiries from qualified contacts who wish to discuss their involvement seriously.

SSP: As you described above, of the three key applications of SHEPHERD, one could be food production for space settlements by creating a fully self-contained biosphere out of an asteroid, a mini-Earth if you will.  This complements your Hot Springs Hypothesis for life’s beginnings in its method for seeding space with life beyond Earth.  Is there an underlying principle linking the origin of life and humanity’s role in extending it beyond the cradle of the Earth?

Series of three images showing cellular mitosis beginning with fission of the nucleus, mitosis underway and completion of the process with daughter cells separated
SHEPHERD Bio with image of Earth overlain on its 500m diameter terrarium world
Mitosis of the Earth into “daughter worlds” represented by the arising of SHEPHERD-Bio in the solar system

Damer: Thank you for asking this question! A couple of years ago I literally sat bolt upright in bed having had a dream of a future vision of the solar system, possibly from the year 2100. A ring of asteroids had become enclosed with SHEPHERD craft or some derivative thereof, and thousands to millions of “new worlds” were orbiting the sun. In nearby orbits were the sharply geometric and tubular shapes of space settlements under construction, housing billions of humans and the organisms with which they cohabitate. Evolution had a future path, moving off our birth world by first creating many new ones. Like the first living cells, the Earth had undergone a spectacular mitosis! I realized in a flash that this future solar system was a huge scale evolution of the ancient hot spring pool cycling with membrane-enclosed protocells which Dave Deamer and I have proposed for life’s beginning. The principal of membranous encapsulation enabling chemical activity and resource sharing acted out four billion years ago in hot spring pools would return to enable life to emerge from the womb of the Earth into a long evolutionary future in the cosmos. It was truly gratifying. You can see how I then wove together these stunning parallel visions in my two TEDx talks below.

The SHEPHERD project is dedicated to the memory and genius of Julian Nott (right) at home in Santa Barbara during my 2014 visit

Links and Resources:

Humanity’s Next steps in Space | Dr. Bruce Damer | TEDxSantaCruz (April 15, 2015):
https://www.youtube.com/watch?v=wLMHcUg36yc

In the Beginning: The Origin & Purpose of Life | Dr. Bruce Damer | TEDxSantaCruz (April 15, 2015): https://www.youtube.com/watch?v=6qiW4aUqtvA

Peter Jenniskens’ first Asteroid Day SETI talk on the technical aspects of SHEPHERD: https://youtu.be/EnCTkUxgtZo

Update July 29, 2021: My interview of Dr. Damer along with David Livingston on The Space Show: https://www.thespaceshow.com/show/13-jul-2021/broadcast-3721-dr.-bruce-damer-john-jossy