Illustration showing concept of operations of the RedWater mining system for water extraction on Mars developed by Honeybee Robotics. Credits: Mellerowicz et al. via New Space
The editorial in the latest issue of New Space, coauthored by two of SSP’s favorite ISRU stars, Kevin Cannon and George Sowers, describes the dawning age of space resource utilization. Cannon, who guest edits this issue, and Sowers are joined by the rest of the leadership team of the graduate program in Space Resources at the The Colorado School of Mines: Program Director Angel Abbud-Madrid and professor Chris Dreyer. The program, created in 2017, has over 120 students currently enrolled. These are the scientists, engineers, economists, entrepreneurs and policymakers that will be leading the economic development of the high frontier, creating the companies and infrastructure for in situ resource utilization that will enable affordable and prosperous space settlement.
How can regolith on the Moon and Mars be refined into useful building materials? What are the methods for extracting water and oxygen from other worlds for life support systems and rocket fuel? Is it legal to do so? Will private property rights be granted through unilateral legislation? What will space settlers eat? The answers to all these questions and more are addressed in this issue, many of the articles free to access.
One of my favorite pieces, the source of this post’s featured image, is on the RedWater system for harvesting water on Mars. This technology, inspired by the proven Rodwell system in use for sourcing drinking water at the south pole, was developed by Honeybee Robotics, just acquired by Blue Origin earlier this year. End-to-end validation of the system under simulated Mars conditions demonstrated that water could be harvested from below an icy subsurface and pumped to a tank up on the surface.
We need to start thinking about these technologies now so that plans are ready for implementation once a reliable, affordable transportation system comes on line in the next few years led by companies such as SpaceX and others. Sowers has been working on thermal ice mining on cold worlds throughout the solar system for some time, predicting that water will be “the oil of space”. Cannon has been featured previously on SSP with his analytical tools related to lunar mining, the Pinwheel Magma Reactor for synthetic geology and plans for feeding millions of people on Mars.
Artist concept of industrial hubs of circular food production including vertical farming, bioreactors, greenhouses, water treatment and energy production. The same technology has duel use and could be leveraged for life support systems in space settlements. Credits: Mark Goerner / Orbital Farm
Typical plans for space settlements include greenhouses for growing plants as a source of food as well as a key component of ecological closed life support systems to help produce air and recycle water. There are efforts to make these space farms as compact and efficient as possible utilizing hydroponics and LED lighting. But the energy, volume, water and labor requirements can still be a challenge. A new approach is described in a paper in New Space by Michael Nord and Scot Bryson that is based on Earth’s dark ecosystem, the food chain based on bacteria that are chemotrophic, i.e. deriving their energy from chemical reactions rather then photosynthesis. An example of these type of organisms are bacteria that live near volcanic sulfur vents at the bottom of the ocean. They synthesize organic molecules from hydrogen sulfide, carbon dioxide and oxygen which in turn nourish giant tube worms.
Giant tube worms nourished by organic molecules synthesized by chemotrophic bacteria near deep undersea sulfur vents. Credits: Biology Dictionary
“Earth’s dark ecosystem affords us an elegant solution.”
This is not new technology. Fermentation is an example of this biological process which humans have been using for thousands of years in the production of food and drink. NASA explored this option in the 1960s in their plans for sources of food to sustain astronauts on long duration space flights. Synthetization of “single-celled proteins” showed promise for astronaut sustenance but NASA’s priorities shifted after Apollo putting less emphasis on manned spaceflight leading to funding cuts, which put these efforts on hold.
Fast forward to today, there are many companies focusing on using dark ecology as an alternative source of protein both for an ever increasing human population and for animal agriculture. The single-celled proteins are produced by fermentation in bioreactors to produce products mainly used in animal feed but at least one firm, Quorn, is focused on human consumption.
Mycoprotein for human consumption produced by fermentation of the fungus Fusarium venenatum. Credits: Quorn
Others in both government and industry are transitioning Earth’s agricultural approach to a circular economy for food, where food waste is designed out, food by-products are re-used at their highest value, and food production regenerates rather than degrades natural systems. Innovations by companies involved in this type of farming here on Earth have direct applications in bioregenerative life support systems in space. Orbital Farm, who’s CEO Scot Bryson coauthored the paper, is one such company exploring commercialization opportunities in this field.
The authors performed an analysis of energy inputs and material flows for conventional photosynthetic food production when compared to a dark ecosystem and found that the latter is 100 times more efficient in water and energy use, and 1000 times better in terms of volume. But that is not all. There is an added benefit in that “…the very same organisms can be engineered to make pharmaceuticals, plastics, and a variety of other useful complex organic compounds.”
The advantages for space settlement are clear. Although photosynthetic plant growth will play a role in life support systems including the added benefit to humans of the aesthetic value of living among plants, dark ecology can augment food from photosynthetic plants with efficient and sustainable protein production.
“…for bulk production of calories, chemotrophic organisms have enormous efficiencies over production with staple crops, which will be nearly impossible to ignore for mission designers.”
Conceptual illustration depicting the deployment sequence of a LEO Moon-Mars dumbbell partial gravity facility serviced by SpaceX’s Starship. Left: Starship payloads being moored by a robot arm. Center: 1.6 m ID inflatable airbeams (yellow) play out from spin access and mate with dumbbell end modules. Rectangular solar arrays deploy by hanging at either end as spin is initiated via thrusters at Mars module. Right: Full deployment with Starship and Dragon docked at spin axis hub. Credits: Joe Carroll via The Space Review
There may be no single human factor more important to understand on the road to long term space settlement than determination of the gravity prescription (GRx) for healthy living in less than Earth normal gravity. What do we mean by the GRx? With over 60 years of human space flight experience we still only have two data points for stays longer than a few days to study the effects of gravity on human physiology: microgravity aboard the ISS and data here on the ground. Based on medical research to date, we know that significant problems arise in human health after months of exposure to microgravity. To name a few, osteoporosis, immune system degradation, diminished muscle mass, vision problems due to changes in interocular pressure and cognitive impairment resulting memory loss and lack concentration. Some of these problems can be mitigated with a few hours of daily exercise. But recovery upon return to normal gravity takes considerable time and we don’t know if some of these problems will become irreversible after longer term stays. We have virtually no data on human health at gravity levels of the Moon and Mars, as shown in this graph by Joe Carrol:
The more important question for permanent space settlements is can humans have babies in lower gravity? If we go by the National Space Societies’ definition, an outpost will never really become a permanent space settlement until it is “biologically self-sustaining”. We evolved over millions of years at the bottom Earth’s gravity well. How will amniotic fluid, changes in cell growth, fetal development and human embryos be affected during gestation under lower gravity conditions on the Moon or Mars? There are already indications that problems will arise during mammalian gestation, at least in microgravity as experienced aboard the ISS.
To answer these questions, Joe Carroll suggests the establishment of a crewed artificial gravity research facility in LEO which he described last month in an article in The Space Review. He proposes a Moon-Mars dumbbell with nodes spinning at different rates to simulate gravity on both the Moon and Mars, which covers most of the planetary bodies in the solar system where settlements would be established if not in free space. The facility could be launched and tended by SpaceX’s Starship once the spacecraft is flight worthy in the next few years in parallel with Elon Musk’s plans to establish an outpost on Mars. Musk may even want to fund this facility to inform his long term plans for communities on Mars. If his goal is for the humanity to become a multiplanetary species, surely will want to know if his settlers can have children.
Carroll’s design connects the Moon and Mars modules with radial structures called “airbeams” which will allow crew to access the variable gravity nodes in a shirtsleeve environment. The inflatable members are composed of polymer fiber fabric which can be easily folded for storage in the Starship payload bay. Crews would be initially launched aboard Dragon until the Starship is human rated.
“Eventually, rotating free-space settlements will get massive enough to use other shapes, but dumbbells plus airbeams seem like the key to useful early ones.”
The paper addresses details on key operating concepts, docking procedures, emergency protocols, and the implications for long term settlement in the solar system.
There may even be a market for orbital tourism to experience lower gravity that could make funding for the facility attractive to space venture capitalists, especially if it is located in an equatorial orbit shielded from ionizing radiation by the Earth’s magnetic fields. As the technology matures, older tourists may even want to retire in orbital communities that offer the advantage of lower gravity as their bodies become frail in their golden years.
Humankind’s expansion out into the solar system depends on where we can survive and thrive in a healthy environment. If ethical clinical studies on lower mammals in a Moon/Mars dumbbell clears the way for a healthy life in lunar gravity then we can expand out to the six largest moons including our own plus Mars. If the data shows we need at least Mars gravity, then the Red Planet or even Mercury could be potential sites for permanent settlement. But if nothing below Earth normal gravity is tolerable, especially for mammalian gestation, it may be necessary to build ever larger rotating O’Neillian free space settlements to expand civilization across the solar system. There are vast resources and virtually unlimited energy if we need to do that. But it will take considerable time and careful planning to establish the vast infrastructure needed to build these settlements. If human physiology is constrained by Earth’s gravity then space settlers will want to know this information soon so that the planning process can be integrated into space development activities about to unfold on the Moon and beyond. If Musk finds out that Mars inhabitants cannot have children and wants to establish permanent communities beyond Earth, would he change course and switch to O’Neillian free space settlements?
“If we do need sustained gravity at levels higher than that of Mars, it seems easier to develop sustainable rotating settlements than to terraform any near-1g planet.”
Listen to Joe Carroll answer my questions about his Moon/Mars dumbbell facility from earlier this month on this archived episode of The Space Show.
Launch of the Space Shuttle Atlantis (STS-66) on November 3, 1994. The mission carried an experiment called NIH.Rodent 1, the first of only two study’s to date on rats launched at mid-pregnancy and landed close to full term to study the effects of microgravity on reproduction. Credits: NASA
In a MDPI Journal Life paper, Alexandra Proshchina and a team* of Russian researchers summarize the research that has been performed thus far on reproduction of invertebrates in space. As mentioned in the article, the only data we have on mammalian reproduction in microgravity since the dawn of the space age is from two experiments carried out over 26 years ago. The studies looked at pregnant rats launched aboard the Space Shuttle on missions STS-66 and STS-70 in 1994 and 1995 respectively, and there have never been any births of mammals in space. This huge knowledge gap on reproduction in space is problematic for human space settlement. Yet Elon Musk, The Mars Society, and other groups are charging ahead with plans for cities on Mars. What if we discover that humans cannot have healthy babies in 0.38g? SSP has covered the quest for determining the gravity prescription before looking at JAXA’s effort to at least start experimenting with artificial gravity in space, albeit on adult mammals (mice). We are still waiting for JAXA’s published results of 1/6g experiments carried out in 2019.
The data from the Space Shuttle program only looked at part of the gestation period (after 9 days) and only in microgravity. The results did not bode well for reproduction in space. Some findings “…clearly indicate that microgravity, and possibly other nonspecific effects of spaceflight, can alter the normal development of the brain itself.”
Histological cross section through a representative rat brain from NIH.Rodent 1 experiment from STS-66. Left side (a) is low magnification and right side (b-d) are high magnification. Red arrows show areas of neurodegeneration. 1 – Nasal cavity, 2 – olfactory nerve, 3 – olfactory bulb, 4 – eye, 5 – cortex telencephali, 6 – hippocampus, 7 – fourth ventricle, 8 – cerebellum. Credits: Alexandra Proshchina et al.*
So we have this one piece of data for reproduction in microgravity and nothing in higher gravitational fields except what we know here on Earth in 1g.
Would partial gravity like on the Moon or Mars be sufficient for normal fetal development in rats (or mammals in general, especially humans) during the full gestation period? If problems are identified could it be extrapolated to human reproduction? The fact that homo sapiens and their ancestors evolved on Earth in 1g for hundreds of thousands of years is a big red flag for future space colonists that hope to settle on the surface of planetary bodies and have children.
We don’t know how lower gravity conditions could affect embryonic cell growth. How would the changes in surface tension and embryo cell adhesion be altered in these environments? We have very little data on cellular mechanisms and embryonic alterations that lower gravity may induce that could affect fetal development.
“There are also many other questions to be answered about vertebrate development under space flight conditions.”
A recent report on giving birth in space by SpaceTech Analytics looks at many of the factors that need to be considered for human reproduction off Earth. Most problems could be potentially mitigated through engineering solutions such as radiation protection, medical innovations tailored for space use, life support technology, etc. In this entire presentation the authors gave very little consideration to partial gravity affects on human embryos and child birth. One slide (number 70) out of 85 discusses these issues.
It is clear that more and longer term experiments will be necessary to determine how partial gravity affects the reproduction and development of mammals before humans settle space. Some researchers are actually considering genetic modification to allow healthy reproduction in space, and the ethical considerations associated with this course of action. Obviously, such a drastic methods would come only if there was no other alternative. One would think that building O’Neill type habitats rotating to produce 1g of artificial gravity would be preferable to such extreme measures.
Clearly, we need a space based artificial gravity laboratory to carry out ethical clinical studies on the gravity prescription for human reproduction, starting with rodents and other lower organisms. SSP recently covered a kilometer long version of such a facility that could be deployed in a single Falcon Heavy launch. And don’t forget Joe Carroll’s proposal for a LEO partial gravity test facility. Doesn’t it make sense to invest in such a facility and do the proper research before (or at least in parallel to) detailed engineering studies of colonies on the Moon or Mars intended for long term settlement? This research could inform decision making on where we will eventually establish permanent space settlements: on the surface of smaller worlds or in free space settlements envisioned by Gerard K. O’Neill. Elon Musk may want to consider such a facility before he gets too far down the road to establishing cities on Mars.
* Authors of Reproduction and the Early Development of Vertebrates in Space: Problems, Results, Opportunities: Alexandra Proshchina, Victoria Gulimova, Anastasia Kharlamova, Yuliya Krivova, Nadezhda Besova, Rustam Berdiev and Sergey Saveliev.
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.
Living space in a Kalpana orbital space settlement. Credits: Bryan Versteeg
Kasper Kubica presents an optimistic business case for space tenants moving in (er, up) to deluxe condominiums orbiting the Earth within 10 years. Initially for the ultra rich, the price tag is comparable to high end real estate currently on the market. Of course the devil is in the details, so lets dive in.
In a post on Medium, Kubica uses the rotating habitat Kalpana as an illustrative example of his “Spacelife Direct” approach for an orbital settlement spinning to create 1G of artificial gravity and hosting north of 400 condominiums in LEO. Such a facility would be shielded from radiation by Earth’s magnetosphere if it were located in low equatorial orbit and therefore could be constructed with less shielding. This results in a significant reduction of mass driving costs way down. Running the numbers on this scenario opens up exciting possibilities with the amazing capabilities of Elon Musk’s Starship currently under development by SpaceX.
Using the scaled down Kalpana Two version as discussed in Tom Marotta and Al Globus’ book, The High Frontier, an Easier Way, the cylindrical habitat is sized at just over 100 meters in diameter and the same in length, weighing in at 16, 800 metric tons. Kubica estimates that it would take 140 launches to loft the required mass to LEO. Assuming costs keep coming down as Starship launch cadence increases (a safe bet), at $10M/launch the cost of just the materials to LEO would be $1.4B. Of course there are many more expenses associated with design, development and fabrication, not to mention insurance of such an orbital condo complex. For the sake of argument Kubica triples that figure arriving at a total price tag of $4.2B.
But would there be a market for real estate in LEO? Kubica provides comparable examples of skyscrapers with similar costs and over 200 condominiums recently selling for over $10M in Manhattan.
“The clamor for earthside luxury condos is massive and growing. Orbital condos — representing an exclusive experience far beyond that available to anyone on earth — could generate astronomical demand.”
With the economics of Starship opening up limitless possibilities, Kubica lays out a roadmap over the next 10 years to realize the Spacelife Direct opportunity. First would come financing the venture though a team of visionary entrepreneurs and investors (are you listening Dylan Taylor?). Design and development would come next including the robotic systems that would be required for assembly in space. Laying the groundwork for this infrastructure may be completed soon by Orbital Assembly Corporation which could potentially be leveraged as a Spacelife Direct supplier. To keep labor costs down much of the facility would be fabricated on Earth in launchable modules that would be assembled in orbit. The final stages would activate life support systems and finish out the interiors for the occupants to begin moving in.
So what about the rest of us? As history has shown in the aerospace industry at the beginning of the last century and we see unfolding in the space tourism market today, the rich help pave the way so that mass production and economies of scale will drive down costs eventually making space settlement affordable for the masses.
“We don’t want to live in space because it’s an economic necessity, we want to live in space because we are explorers and adventurers, and space is humanity’s next frontier!”
One kilometer long spinning space station producing 1G of artificial gravity deployed from a single Falcon Heavy launch vehicle. Credits: Zachary Manchester, graphic by Tzipora Thompson
This year’s NASA Innovative Advance Concepts (NIAC) award winners presented their ideas in a virtual poster session last week. Zachary Manchester of Carnegie Mellon University and Jeffrey Lipton at the University of Washington have come up with a rotating habitat to produce artificial gravity. But to do this without causing severe disorientation that would result from a short radius habitat, their novel facility is one kilometer long spinning to produce 1G at both ends. Manchester and Lipton’s innovation is a deployment mechanism that leverages advances in “mechanical metamaterials” to reduce mass while increasing expansion ratios such that the structure can be squeezed into a single Falcon Heavy payload envelope but when deployed, expands to 150 times its stored configuration size. The structure can be erected autonomously and without any assembly in space.
The key enabling technologies are a combination of “handed shearing auxetics” (HSA) and branched scissor mechanisms. HSA is described in a 2018 paper in Science by Lipton and other researchers where they “…produce both compliant structures that expand while twisting and deployable structures that can rigidly lock.”
“The station can…be spun at 1-2 RPM to generate 1g artificial gravity at its ends while still maintaining a microgravity environment at its center near the spin axis, providing the crew with the flexibility of living in a 1g environment while performing some work in microgravity.”
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.”
Conceptual illustration of a planetary sunshade blocking a fraction of sunlight from reaching Earth at the L1 Lagrange point. Credits: Planetary Sunshade Foundation
The Planetary Sunshade Foundation (PSF) would answer “Yes!” to both questions. In a paper presented at the AIAA ASCEND conference in 2020 on the group’s website, the authors* lay out a well researched case on feasibility. The technology needed to build such a megastructure, envisioned to be located at the Earth-Sun L1 Lagrange point, will depend heavily on resource extraction on the Moon and Near Earth Asteroids as well as in-space manufacturing, both of which are anticipated to be mature industries by mid-century.
Building such a megastructure will be a huge undertaking and would require significant funding as well as international cooperation among world governments. PSF and many other groups (including President Joe Biden) take the position that global warming is an existential threat and therefore mitigating its effects are worth the costs. The foundation says on their website that “We have only ten years to dramatically decrease the use of fossil fuels, or be forced to respond to catastrophic global warming.” Other credentialed climate scientists interpret the same data differently disagreeing that if we don’t act now the impact will be catastrophic. They believe that a more gradual transition based on innovation and adaption would make more economic sense.
Dr. Steven Koonin, who served as Undersecretary for Science in the U.S. Department of Energy under President Obama, in his book “Unsettled” uses data from the UN Intergovernmental Panel on Climate Change to show that the impact on the U.S. economy near the end of this century due to the worst scenario of predicted global temperature rise would be minimal. Therefore, in his view the warnings of an “existential threat” are not supported by the data.
Bjorn Lomborg takes the position that rather than making an abrupt change to our economy of reducing carbon emissions to zero by mid century, which is projected to impose significant economic costs and lower standards of living, we need to ramp up our investments in green energy innovation. This would include research and development in renewable energy technology such as solar and wind power, improving battery efficiency, nuclear power and other options to more gradually migrate away from fossil fuels.
The idea of placing a sunshade at L1 to cool the planet is not new, as evidenced by a few examples listed as references in the PSF paper. One of the references published back in 2006 by Roger Angel, Professor of Astronomy and Optical Sciences at the University of Arizona, examines the “Feasibility of cooling the Earth with a cloud of small spacecraft near the inner Lagrange point (L1)”. Angel realized that embarking on such an ambitious endeavor should only be initiated to avert serious climate change “…found to be imminent or in progress.” He concludes that “The same massive level of technology innovation and financial investment needed for the sunshade could, if also applied to renewable energy, surely yield better and permanent solutions.”
Such major undertakings among world governments are by nature political, but if agreement is eventually reached by stakeholders on the urgency to build a planetary sunshade, the option will be available to humanity in the near future should it become necessary. The planetary sunshade is technically possible with future technology advances and has the potential for other benefits. For example, if the structure is made from thin-film photovoltaics, it would be possible to collect enough solar energy to provide hundreds of terawatts of power which is many times the current needs of Earth (currently 17TW). PSF believes the sunshade megastructure “…could generate civilization-transforming energy supplies.” The authors even suggest that a toroidal colony like the one conceived in the NASA 1975 Space Settlement Design Study could be constructed nearby to house workers supporting the manufacture of the sunshade and be “…combined to create banded toroidal settlements as well, scaling linearly, depending upon the population needs of the settlement.”
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* The authors ( A. Jehle, E. Scott, and R. Centers) of the paper “A Planetary Sunshade Built from Space Resources” as of last year were graduate students in the Center for Space Resources at the Colorado School of Mines in Golden, Colorado. Centers and Scott are Director and Systems Engineer, respectively on the PSF Team.
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 theUK. 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.
