Why settle space?

Artist depiction of the interior of a cylindrical space colony during an eclipse of the sun. Credits: Don Davis / NASA Ames Research Center

This question has come up a lot lately in the press, usually in the context of how public funds should be spent in space.  On the affirmative side, the answer has been addressed well by many space advocates over the years. Elon Musk wants to make the human race a multi-planetary species in case of a catastrophe on Earth and to expand consciousness out into the cosmos starting with Mars. Jeff Besos wants to move industrial activity off world and eventually fulfill Gerard K. O’Neill’s vision of trillions of people living in free space colonies. When asked the question last year by American Enterprize Institute’s James Pethokoukis, Robert Zubrin said: “In order to have a bigger future. In order to have an open future. In order to open the possibility to create new branches of human civilization that will add their creative talents to the human story. ” He thinks Intellectual Property will be the main export of a Mars colony and he’s already kickstarting that process with the Mars Technology Institute. And of course, The National Space Society (NSS) provides clear rationale in the introduction to their Roadmap to Space Settlement.

On the negative side, there are many naysayers. Some even say humans will never live in space. NSS Board Member Al Globus does a great job of refuting these viewpoints.

In an effort to gain deeper insights and clarify the vision of space settlement, SSP reached out to several space advocates, academicians and entrepreneurs to gather as many viewpoints as possible. They were asked if they agreed with the viewpoints above or if they had a different take.  Regardless of if we are asking for public support for government efforts through space agencies, if the efforts will be funded by private individuals or through a combination of public/private partnerships, why should humanity settle space? Here are their answers:

Doug Plata MD MPH, President & Founder of the Space Development Network, makes the case that there is no need to convince the public of the value of space:

“Many space advocates argue that the general public needs to be convinced of the value of space if we are ever going to see space development occur. So, these advocates come up with a wide variety of arguments including: the necessity of securing large amounts of public funding, the value of satellites in our everyday lives, the potential for a huge “space economy”, inspiring the next generation, and even for the survival of the human species.

“But is convincing the general public actually necessary? Put another way, will off-Earth settlement be impossible unless polls show a large percentage of the public supports space settlement?

“Secondly, it is not the general public who will be deciding whether they will settle on the Moon and Mars. Specifically, the uninterested, the cynical, nor the leftist opponent will need to be convinced over their objections. The ones who will decide will be countries choosing to send their hero astronauts to represent their own people and also private citizens who have saved up enough money. If countries have national pride (practically all) and if there are any “early adopters” with enough savings to pay for their ticket and stay, then it will be those who will decide to go. From Elon’s first BFR presentation (Guadalajara), this has been his business case and I find it to be sufficient. We don’t have to imagine some sort of unobtanium to trade with Earth to figure out where the funding will come from.

“For starters, much of the recent progress in space has not been the result of a groundswell of support from the public. Both Elon Musk and Jeff Bezos started their path to radically reducing the cost of launch independent of any groundswell of support for space by the public. And it is significant to note that they obtained their considerable wealth thanks to their Internet companies that had little, if anything, to do with space. It is their vast wealth that now gives them the ability to develop the reusable rockets which will make space development and settlement affordable and, as a result, inevitable. Even if NASA’s budget is cut to zero, Bezos will still have 20 X the wealth of NASA’s annual human spaceflight budget with Musk’s wealth at 30 X. And both are making progress with their heavy lift vehicles in a significantly more cost-effective manner than NASA.

“In conclusion, the cynic cannot be convinced, and it is probably a waste of time to try. But for those who have their own reasons for wanting to go, so long as the price has been brought down low enough…it is they who will inherit the stars. To each his own.”

Image of the Space Development Network’s full-scale mockup of an inflatable permanent habitat for the Moon or Mars at ISDC 2023. The concept is intended to demonstrate how a 100 tonne SpaceX Starship payload could be delivered and deployed to create a habitat with a 1 acre footprint. Credits: Doug Plata / Space Development Network

Dr. Daniel Tompkins, an agricultural scientist and founder of GrowMars weighs in:

“To address the term settlement from a biological view, for me it means to settle on a process or methodology to sustain and expand water/food/housing. There is settling the land to provide these things (where and how to get clean water, grow/harvest food, get building material). there is settling on practices that are reproducible with multi generational intent. Building schools, planning for expanding population. Different than an oil platform or remote research center which aren’t considered sea steading or settling Antarctica for the multigenerational intent reason.

“To answer directly on various views, mixed on positions:

“Musk- agree Mars is “easy” and most scaleable [sic]. Disagree that sustainable cites or a million people is a magically successful benchmark. Showing ability to support expanding population regardless of scale is important. How do you go from the resources to support 2 people, to 4 people.

“Zubrin- practical and pragmatic about challenges for human missions to Mars and how they can potentially accelerate the science and search for life beyond Earth. Agree IP is best export to support Mars economy lb for lb., particularly genetic engineering and synthetic biomanufacturing. Also agree on term resource creation vs term ISRU.

“Bezos- Moon is more difficult then Mars to “settle” lacking useful carbon and nitrogen than Mars, but opens a bigger range of options for where we can, the trillion people in the solar system model. The thermodynamics of habitats and greenhouses in these places isn’t well established or realized and there are misconceptions to this point of Mars being too cold.

“NSS- disagree with undertone of unlimited power needed to solve for space and earth to bring post scarcity. Unlimited biology vs unlimited power argument.

“O’Neill mostly addressed in above views, specifically cylinders are inspiring, but the process to make them not shown to make people think reproducible. Also, micrometer impacts.

“My short response to the space community and wider is that regardless of where in space (orbit, lunar, Mars etc.), space settlement is about learning to thrive independent of Earth’s natural resources in extreme environments. Whether we go to space or not, we are going to have to solve the same problem sets, i.e. clean air, water, food, materials on Earth in 50-100 years, if not sooner. It means you don’t have to fight with [your] neighbor or chop down the rainforest for more resources, you can do resource creation anywhere on Earth and meet basic needs.

“Space settlement level hardware should not be an eventually, it can be smaller than traditional mission payloads and de-risk certain mission architectures. Which is less mass/volume. Food for 3 years, greenhouses, or a machine to make greenhouses? Some of all three would be good, especially in certain scenarios.

“With sustainable independent settlement as a benchmark, practices and processes need to be inherently reproducible and serviceable. Similar and inspired methods could be used on Earth with limited resources in extreme environments to bootstrap resource creation to meet basic needs.”

Conceptual illustration of a habitat on Mars constructed from self-replicating greenhouses. Credits: GrowMars / Daniel Tompkins

Dr. Tiffany Vora, VP of Innovation Partnerships at Explore Mars and Vice Chair of Digital Biology and Medicine at Singularity University, had the following take:

“In my mind, there are three big arguments in favor of humans moving off-planet for extended, if not permanent, habitation.

“First, we more or less have the technologies that we need in order to do so, as well as a burgeoning space economy. I view crewed space habitation and settlement as further spurs to technological and economic development that will drive deeper understanding of the world around us while creating jobs and, hopefully, prosperity beyond a privileged few. That technology development has the added benefit of improving life on Earth, for example by contributing to solutions to the UN SDGs—on the way to setting the stage for sustainable human habitation off Earth.

“Second, as a biologist, I simply cannot believe that we are alone in the universe. I can’t even bring myself to believe that we’re alone in the Solar System! I view exploration and long-term settlement as key components of finding life off Earth, learning how it works, and learning from how it works. Serving as stewards of non-Terran life would be a momentous responsibility for humanity; although we have a dismal record of that here at home, I believe that life anywhere in the universe is a precious thing that would be worth a deep sense of obligation on the part of humans. Alternatively, failing to locate life elsewhere in the Solar System could provide strong messaging about the fundamental science of life—and hammer home the precarity and beauty of life on Earth.

“Third, I still believe in the capacity of space to inspire people, across generations and boundaries and even ideologies. The goal of settling space isn’t only about setting boots on exotic landscapes: it’s about staring at unbelievably complicated and dangerous challenges and saying, “Let’s do this—and here’s how I’m going to help.” I grew up in Florida, standing in my backyard watching shuttle launches. I have never lost the feeling that I had as a kid, witnessing that. I want every child on Earth to feel that sense of inspiration, of desperate excitement about the future—as well as a compelling urge to be part of it. Sure, I’d love for that to inspire STEMM careers, but there are so many other ways to contribute!

“Obviously, every word that I’ve written here comes with its own caveats. But just as I believe in these words, I also believe in our ability to make choices that open up an abundance of possible futures to bring prosperity and peace, not just to as many people around the world as possible, but to our own planet. The key is choices, and those choices have to be made starting today.”

Science journalist and historian Robert Zimmerman in his book Genesis, The Story of Apollo 8, wrote this:

“The new century will see a renaissance of space exploration as exciting and as challenging as the space race in the 1960s. And this rebirth will happen under the banner of freedom and private property, the very principles for which the United States fought the Cold War.”

Zimmerman continues:

“In a larger more philosophical perspective, we settle space because that’s what humans must do. It is the noblest thing we can do. To quote myself again, this time from my 2003 history, Leaving Earth:

‘Our hopes and dreams are a definition of our lives. If we choose shallow and petty dreams, easy to accomplish but accomplishing little, we make ourselves small. But if we dream big, we make ourselves great, taking actions that raise us up from mere animals.’ “

“Earthrise” image taken by astronaut Bill Anders from Apollo 8 on Christmas Eve 1968. Note that this is the original orientation of the image. As pointed out by Zimmerman, it was rotated 90o by the press for dramatic effect. Credits: William Anders/NASA

Entrepreneur and inventor Ryan Reynolds had a refreshingly unique perspective:

“So, why should humanity settle space (remotely and in-person)?:

  • To be confronted with a new set of challenging environments.
  • Feel the struggle to understand and adapt to them. 
  • Benefit from the effort through shared insights and tangible gains for all. 
  • To observe ourselves outside of the cradle, and know better what we are. 
  • To gain a broader view of our kinship with all that exists. 
  • To be surprised and appalled at our behavior out there. 
  • To ensure that the story does not end here. 
  • To extend biology’s reach.”

Dr. Peter Hague, an astrophysicist in the UK who blogs on Planetocracy had this to say:

“The solar system can and will, eventually, support civilisation on a more larger scale than exists on Earth. There is 2 billion times as much energy available from the Sun in the wider solar system as falls on the Earth alone, and huge reserves of raw materials. The composition of this civilisation will be determined by which nations make investments now – they will get to populate the new society, set the rules and inspire the culture. So it’s in the interests of nations to have a stake in the future, or be irrelevant in a few centuries.”

Haym Benaroya, Distinguished Professor of Mechanical and Aerospace Engineering at Rutgers University and author of Building Habitats on the Moon provided these views:

“I often have to defend the efforts and resources that have been used, and will continue to be allocated, for the space program, and especially the manned space program. While one can rightly say that the funds expended is miniscule as compared to other things that governments and people spend vast sums on, this argument rings hollow. I prefer to point to space, its exploration and its settlement, as an open-ended human adventure and imperative that provides young generations a positive vision of their future, one that gives hope to them and their decedents. Simultaneously, it offers the likely significant technical developments that would not occur otherwise. These technologies will impact how humans will live. Their health will improve, their lives will be longer, more fulfilled, and with the potential for great achievements. There is also the hope that with greater abundance for all on Earth, which a potentially vast space economy can provide, the tolerance for wars will decline. This last idea is a bit utopian given the history of the human race, but it is not a fantasy. It is a potential. Space can increase that potential in a major way.”

Dr. David Livingston, creator/host of The Space Show and one of today’s foremost authorities on the New Space economy, had this thought-provoking vision:

“Space settlement is a visionary long-term project.  In addition, I’m confident that be the inevitable outcome pushed by a global humanity wanting to go to space for off-Earth experiences, living off-Earth and eventually creating off-Earth communities.  I see it as a natural outgrowth of innovation, advancements in all walks of life and in our desire to see and check out what lies just around the corner.  Over time this will happen within the private commercial section of our economy with government mostly working to provide enabling rules of the road to mitigate some risks and uncertainty through establishing order and reasonable protocols. To breathe life into this vision so that it becomes reality, collectively we need to anchor our vision in science, engineering, medical development, behavioral science and most likely many more foundational components so that what we build and stands the test of time on solid footing. Having a dream and a vision for space settlement is one thing but to work on it, to enable it, to develop it, to make it come about implies we are a free people able to pursue dreams, to turn them into reality and to create amazing outcomes that were not even in existence yesterday. But its not enough to just have a good dream or vision for the future. We need to be able to make it happen which to me implies having a solid foundation not Bay Mud, plus realistic, plausible outcome expectations that are only possible when we can explore, build, and develop as we see fit. When we can take risks.  Being free to push forward to what lies beyond Earth is as essential as all the other ingredients that will go into making space settlement happen because without that freedom, we will have our dreams but without the ability to make them real.

“I’m fully aware that the settlement discussions like to focus on operational timelines, rockets, engineering, medical, food, and all sorts of challenges.  While all of this is critical to developing space settlement, these discussions must not sidetrack us into a world of hypotheticals and perspectives suggesting this or that technology is best given our present state of settlement R&D. Since I firmly believe that the private sector should make settlement happen, more so than the government, I would like to see viable commercial projects and startups designed to enable and support the goal of settlement. Government too has an important role in establishing space settlement. Rules of the road and policies are needed to provide order, structure, and safety.  One of our primary relationships with government must be oversight so that we enable not curtail settlement development.

“Space Settlement is fraught with challenges, with naysayers and those that think they know best for others.  I have every confidence that we will in time be overcome these obstacles.  By showing and doing, not by talking and promising.  I’m in less of a hurry to see the first settlement than I am in seeing us get started with essential precursors such as long-term commercial project financing as an example.  Space settlement will likely evolve because of a step-by- step methodical approach to information and fact gathering, problem solving, testing, development, and more testing. Risk taking will play a very large role in our ability to move forward.  As for risk taking, it can only be taken by those with the freedom to do so. As we advance step by step, innovation and forward thinking by those on the front lines will play an increasingly valuable role in turning our vision into reality.

“Space settlement is and should be a global endeavor with unlimited motivating and inspiring reasons driving thousands if not millions of us to our goal. As we move forward, we are sure to uncover and use many of the tightly held secrets of our universe. For sure it will be a very exciting and rewarding adventure as we figure out how to live, work, and play off-Earth, all the while making sure the process and our off-Earth communities are sustainable and independent on an ongoing basis.  This will happen if we remain focused and avoid distraction. Having patience will help us stay the course and to develop and maintain our needed drive into the future.  A future that to me lies ahead of us with as much certainty as does our daily sunrise and sunset.”

Tom Marotta, CEO of The Spaceport Company and Brett Jones, Strategic Marketer and Frontier Tech investor cowrote this inspiring response:

Reimagining the Stars: A Multiplanetary Mindset for a Flourishing Future
The challenges humanity faces today are vast. From the instability of our global systems to the dwindling resources and fading hopes, there’s an undeniable sense of stagnation. Yet, within this atmosphere of despondency lies a beacon of hope, a path toward rejuvenation: the cosmos. Imagine a world where resources are not just abundant, but practically infinite. Where our collective potential is not limited by the boundaries of our blue planet, but instead, expanded by the boundless wonders of space. Such a vision is not mere science fiction; it is a future within our grasp.

Space: An Oasis of Resources and Possibilities
Outer space is not just about twinkling stars and distant planets. It’s a treasure trove waiting to be explored. The vast quantities of materials and energy floating in the cosmic expanse can fuel economies, revitalize our planet, and secure prosperous futures for generations. And it’s not just about physical resources. The challenges of space exploration will drive advancements in healthcare, technological innovation, and even the social fabric of society.

New Frontiers, New Beginnings
Space offers a fresh canvas, an opportunity to redefine human existence. For those yearning for change, be it a new environment, companionship, or the thrill of exploration, the cosmos holds endless possibilities. It’s not just about survival; it’s about thriving in ways we have yet to envision.

Redefining NASA’s Mission: From Pride to Purpose
NASA has always been a symbol of American pride. Its achievements, from landing on the moon to exploring the distant reaches of our solar system, are testament to human ingenuity. Yet, its true potential lies not just in exploration, but in transformation.

“For NASA to truly leave an indelible mark on every individual, it needs to shift its vision. Instead of focusing solely on exploration and scientific endeavors, the emphasis should be on providing direct benefits for every citizen. This involves prioritizing space settlements, harnessing energy from space, and leveraging cosmic resources.

An Invitation to the Stars
As we stand on the cusp of a new era, we must choose the trajectory of our future. By adopting a multiplanetary mindset, we’re not just securing a better life for ourselves but ensuring the continued growth and prosperity of all humankind for millennia to come. The universe beckons, offering hope and possibilities. It’s up to us to answer the call.”

Conceptual illustration of a mobile offshore launch platform as part of a robust launch industry infrastructure servicing thousands of launches in the near future to support space development. Credits: The Spaceport Company

Daniel Suarez, author of Delta-V and Critical Mass, believes we should rephrase the question:

“The question of ‘why’ humanity should settle space has been debated ever since it became technologically possible in the late 1960’s and early 1970’s. And the question has renewed relevance here in 2023 with the launch of a new space race — both public and private. A frequent objection is: “Why should we spend precious resources on space development when we have pressing problems to solve down here on Earth?”

“However, to address that concern I think it’s vital to re-frame the question as not just ‘why’ we should settle space, but why we must urgently settle space. And the answer is compelling: we must settle space in order to deliver economic opportunity and clean energy to all the people of Earth, particularly if we are to have a reasonable chance of resolving the existential threat of climate change. One may question how expanding human society and industry into space accomplishes that, but the answer is straightforward…

“Yes, developed nations have made progress in reducing their carbon emissions in an effort to address climate change. And yes, more consumers are buying electric cars. However, social media and mainstream news reports tend to suggest climate change will soon be under control if we just continue installing solar & wind farms, and keep buying electric cars. However, the truth is that human civilization as a whole is not reducing carbon emissions. In fact, for all our efforts over the past 30 years all we’ve done is slow the growth of emissions. For example, global carbon emissions increased yet again (0.9%) in 2022 and that increase was above the 6% increase from the year before (source: National Oceanic & Atmospheric Administration). Pointedly, carbon emissions have increased almost every year since the dawn of the industrial age in 1850 (a notable exception being 2020, during the height of the pandemic).

“The amount of CO2 in the atmosphere today was last experienced 4.3 million years ago, during the mid-Pliocene epoch when sea levels were 75 feet higher than today, and average temperatures were 7 degrees Fahrenheit warmer than pre-industrial times. Even if we reduced annual global carbon emissions to zero tomorrow, average global temperatures would still continue to rise each year for a century or more because of the trillion tons of CO2 that we’ve already released into our atmosphere since 1850. That CO2 will take a century or more to be sequestered by the natural carbon cycle, which means there will be a surplus of heat absorbed by the planet each and every year no matter how many solar panels, wind turbines, and hydro power stations we install.

“No, in order to truly address climate change, we’re going to need to remove CO2 from Earth’s atmosphere, reducing concentrations from the present 418ppm down to at least 350ppm, a level more suitable to global civilization. But coming up with the terawatts of clean energy required to remove all that CO2 is going to be nearly impossible here on Earth, especially as economic and political turmoil continues to spread in response to climactic chaos.

“Adding to the challenge of resolving climate change is the fact that over 2 billion people currently live in poverty and billions more experience meager living standards. They are eagerly trying to improve their circumstances through economic development and increased energy usage. India, China, nations of Africa, and elsewhere want to improve the lives of their citizens just as developed nations of the West did over the past 150 years. They need energy to do so, and new coal and gas-fired power plants are coming online in the developing even as they continue to roll out solar and wind.

“How can we possibly increase the energy and resources available to the people of Earth without further polluting our already ailing home world — especially in time to stave off the worst effects of climate change, which will itself cause more conflict, uncontrolled migration and food shortages, reducing cooperation on global issues? Earth is a finite system, and the solution to climate change and continued economic development worldwide lies in going beyond Earth’s atmosphere to obtain the energy and resources we need.

“One answer is to expand carbon-intensive industry and energy generation into cislunar space. By using in-situ resource utilization in deep space (as opposed to launching all our working mass from Earth), we can start to rapidly build out an offworld industrial infrastructure & economy, using resources harvested from our Moon and near-Earth asteroids. By refining these materials in space, we can build enormous solar power satellites, place them in geosynchronous orbit, and beam at first gigawatts and later terawatts of clean solar power to rectennas on the Earth’s surface 24-hours a day, rain or shine anywhere in the hemisphere beneath them. The technology to accomplish this has existed since the mid-1970’s. And Earth’s geosynchronous orbit, safely populated with solar power satellites could return well over 300 terawatts of continuous clean energy — and for reference we currently consume a bit over 20 terawatts of energy worldwide.
Plus, the economic growth made possible by expanding industry and energy generation into cislunar space will be critical for all the people of Earth. This could include industries only possible in the microgravity and/or near-perfect vacuum of space, from ultra-clear ZBLAN fiber optics, exotic alloys, pharmaceutical discovery, astronomy — the list goes on.

“So ‘why’ should we settle space? I contend that’s the wrong question. The right question is ‘why should we urgently‘ settle space? And the answer is to avoid an existential catastrophe and instead make possible a promising and dynamic future for countless generations to come.”

Artist depiction of a space-based solar power satellite collecting sunlight and converting the energy to microwaves for beaming to rectennas on Earth to be fed into a country’s power grid. Credits: © ESA – Andreas Treuer

Finally, here are the reasons for space settlement articulated as goals in 1976 by Gerard K. O’Neill from his blueprint for migration off Earth, The High Frontier:

  • Ending hunger and poverty for all human beings
  • Finding high-quality living space for a world population which will double withing forty years, and triple with another thirty, even if optimistic estimates of low-growth rate are realized
  • Achieving population control without war, famine, dictatorship, or coercion
  • Increasing individual freedom and the range of options available to every human being
Cutaway view revealing interior of a toroidal space settlement. Credits: Rick Guidice / NASA Ames Research Center

Sex in space and its implications for space tourism and settlement

AI generated image of an amorous couple embracing in a space tourist destination. Credits: DALL-E

Last April, an international team of researchers published a green paper to solicit public consultation on the urgent need for dialogue concerning uncontrolled human conception which will be problematic for space tourism when it takes off in the near future.   A coauthor on the paper, Alex Layendecker of the Florida based Advanced SpaceLife Research Institute (ASRI) studied the subject for his PhD thesis. Layendecker gave a talk at ISDC 2023 entitled Sex in Space in the Era of Space Tourism in which he emphasized the huge knowledge gap we have on mammalian conception, gestation and birth in the high radiation and lower gravity environments of outer space.  Since humans evolved for millions of years in Earth’s gravity protected from radiation by our planet’s magnetic field and atmosphere, there is a significant risk of developmental abnormalities in offspring which could result in legal liability and potential impacts on commerce if conception occurs in space without consideration of the potential hazards.  After his talk, I discussed these matters and the implications for space settlement with Alex who agreed to continue our discussion in an interview by email for this post.

SSP: Alex, it was a pleasure meeting you at ISDC and thank you for taking the time to answer my questions on this important topic.  The green paper is attempting to foster discussion from relevant stakeholders on addressing “uncontrolled human conception”.  Uncontrolled is defined in the paper as “…without societal approval for human conception – i.e. without regulatory approval from relevant bodies representing a broad societal consensus.” I am not aware of any regulatory authority on these matters at this time and there will likely be considerable challenges to obtain consensus across the space community before tourism becomes mainstream. The intent of the paper appears to be to help develop a framework for regulations (or guidelines) before space tourism takes off. Given how long it takes for regulations to be implemented and the challenges of international consensus, will there be enough time to implement sufficient controls before conception happens in space?

AL:  Great question – short answer up front, no, I don’t believe any “controls” will be implemented before the first incidence of human conception in space, given the timelines we’re currently looking at.  As you mentioned, regulations can take a long time to come into effect and you need to have a basis for establishing regulations/law – space law itself is still being developed.  Our knowledge of reproduction in space is minimal at this stage, certainly not at the level it needs to be at this point of history.  We’re also in virtually unexplored territory when it comes to mass space tourism – there have been space tourists in the past, Dennis Tito being the first “official” space tourist in history over 20 years ago – but all previous individuals that went into space for tourism purposes have done so while integrated into the crew, typically with very little privacy and a considerable amount of training.  With mass access to space, we’ll soon have groups of individuals going up solely for vacation/leisure purposes, and you can be assured some of them will be engaging in sexual activity.  While it would be absurd to try to implement or enforce laws preventing sexual activity in those environments, the dangers associated with potential conception still exist.  What is critically needed at this point is a better collective understanding of those dangers, their mitigation, and for space companies to be able to provide those paying customers with enough information that informed consent can be established – space is inherently dangerous already, and people launching into space are briefed on that.  They will need to be briefed on the dangers associated with conception in space as well, which could not only potentially threaten the life of the baby but also that of the mother, depending on the times and distances involved.

SSP: Will this be a government effort (since a green paper typically implies government sponsorship) or a self-imposed industry-wide trade association consensus approach like CONFERS? Or a combination?

AL: I think in the immediate sense, there will need to be a self-imposed industry consensus on establishing informed consent among space tourism customers. Sex and potential conception in space is currently a blind spot for would-be space tourism companies, because up to this point many of them haven’t considered the dangers it could pose to their customers, and corporate liability here is also an issue. It’s their responsibility to keep their passengers safe, and to inform them of any dangers to the max extent possible. I don’t necessarily see governments being able to implement or enforce any regulations in this regard, because regulating people doing what they want with their own bodies in the privacy of their own bedrooms typically doesn’t fare well over the long term. Where governments may get involved is if any medical situation develops to the point of needing rapid rescue, but Space Rescue capabilities is another topic.

SSP: Space tourism is likely to attract thrill seekers and risk-takers who are likely to have rebellious personalities with a reluctance to follow rules and regulations, let alone respect for societal norms. If this is the case, will pre-flight consultations on the risks of uncontrolled conception and legal waivers be sufficient to prevent risky behavior? Can the effectiveness of this approach be tested prior to implementation?

AL: Prevent risky behavior? Absolutely not. As you point out, these are folks who are intentionally undertaking an enormously risky endeavor in flying to space already, and at least in the early years, will be primarily comprised of your limits-pushing, boundary-breaking types. So they’re already about risk as individuals. However, legal waivers will of course be part of the whole operation, likely to include waivers around the risks of conception. Waivers or not, people are still going to engage in sex in space, and relatively soon, and if the individuals in question are capable of conception, the act itself brings that risk. Not to mention that there are individuals out there who will be vying for the title of “first couple to officially have sex in space,” despite speculation over the years that it could have occurred in the past. To be part of the first publicly declared coupling in outer space will land their names in history books. Now, there will be individuals who decide that they don’t want to deal with those risks after a thorough briefing on the potential dangers, but not everyone – probably not even a majority, knowing humans – will be deterred.

SSP: The paper highlights concerns about pregnancy in higher radiation and microgravity environments. From a space settlement perspective, radiation is less of a problem as there are engineering solutions (i.e. provision for adequate shielding) to address that issue. The bigger challenge will be pregnancies in microgravity, or in lower gravity on the Moon and Mars. The physiology of human fetus development in less than 1g is a big unknown. Some space advocates such as Robert Zubrin brush this off with the logic that a fetus in vivo on Earth is developing in essentially neutral buoyancy, and is therefore weightless anyway, so gestation in less than 1g probably won’t matter. Setting aside the issues associated with conception in lower gravity, if a woman can become pregnant in space, do you think this logic may be true for gestation or are there scientific studies and/or physiological arguments on the importance of Earth’s gravity in fetal development that refute this position?

AL: I’ve heard the neutral buoyancy argument before but it doesn’t address all the issues by a long shot. There is more neutral buoyancy during the first trimester of gestation but in the second and third gravity is very important, even just logistically speaking. Gravity helps the baby orient properly for delivery, and helps keep the mother’s uterine muscles strong enough to provide the necessary level of contractions to safely move the baby through the birth canal. On a more cellular level, cytoskeletal development is impacted by gravity, so even proper formation and organization of cells can be affected by microgravity throughout the span of gestation, from conception to birth. Gravity has a huge impact on postnatal development as well – in the small handful of NASA experiments we’ve conducted using mammalian young (baby rat and mouse pups), there were significant fatality rates among younger/less developed pups against ground control groups when exposed to microgravity during key postnatal phases. The youngest pups (5 days old) suffered a 90% mortality rate, and any of the survivors had significant developmental issues. So gravity is crucial not just to fetal development but to newborns and children as well, that much is evident from the data we do have.

SSP: Following up on your response, the Moon/Mars settlement advocates will say partial gravity levels on these worlds may be sufficiently higher than in microgravity to address the issues you mentioned – baby orientation, cytoskeletal development, cellular formation/organization, postnatal development – and a full 1g may not be needed for healthy reproduction.  The mammalian studies you mentioned with detrimental postnatal development were in microgravity.   We now have a data point at the lunar gravity level from JAXA with their long awaited results of a 2019 study on postnatal mice subjected to 1/6g partial gravity in a paper in Nature that was published last April. The good news is that 1/6g partial gravity prevents muscle atrophy in mice. The downside is that this level of artificial gravity cannot prevent changes in muscle fiber (myofiber) and gene modification induced by microgravity. There appears to be a threshold between 1/6g and Earth-normal gravity, yet to be determined, for skeletal muscle adaptation.  Have you seen these results, can you comment on them and do you think they may rule out mammalian postnatal development in lunar gravity?  

AL: With regard to the JAXA study, I think I’ve seen a short summary of preliminary results but haven’t gotten to read the full study yet. What I will comment for now is that there’s at least some promise in those results from a thousand foot view. While we still need to determine/set parameters for what we as a society/species consider medically/ethically acceptable for level of impact (obviously there was gene modification in the JAXA mice), there are clearly still some benefits to even lower levels of gravity.

SSP: With respect to risk mitigation and the paper’s recommended area of research: “Consolidation of existing knowledge about the early stages of human (and mammalian) reproduction in space environments and consideration of the ensuing risks to human progeny”, SSP has covered off-Earth reproduction and highlighted the need for ethical clinical studies in LEO to determine the gravity prescription (GRx) for mammalian (and eventually human) procreation.  During our personal discussions at ISDC, you mentioned ASRI’s plans for such studies in space.  Can you elaborate on your vision for mammalian reproduction studies in variable gravity?  What would be your experimental design and proposed timeline?

AL:  Well, with regard to timelines, humanity as a whole is already behind, so we’ll need to move as quickly as we possibly can while still upholding safe medical and ethical standards.  We’re approaching an inflection point where human conception in space is more probable to occur, and we still have vast data gaps that need to be filled on biological reproduction.  I’d advocate that the best way to go about filling those gaps would be a systematic approach using mammalian test subjects to determine safe and ethically acceptable gravity parameters for reproduction.  We already know a decent amount about the impacts of higher radiation levels on reproduction from data gathered on Earth, but with microgravity we’ve still got a long way to go, and we don’t know what the synergistic effects of microgravity and radiation are together either.  With regard to experiments, NASA researchers have actually already designed extensive mammalian reproduction experiments with university partners, but those experiments haven’t been funded by the agency.  There was a comprehensive experiment platform called MICEHAB (Multigenerational Independent Colony for Extraterrestrial Habitation, Autonomy and Behavior) that was proposed back in 2015, around the time I was completing my PhD dissertation.  It would effectively be a robot-maintained mini space station that would study the microgravity and radiation effects on rodents in spaceflight over multiple generations, which of course requires sexual reproduction.  That experiment alone would prove enormously beneficial to data collection efforts.  It would be important to study said generations and physiological impacts at variable gravity levels as you mentioned – think the Moon, Mars, 0.5g, 0.75g and so on, so we could fine tune what level of impact we as a species are medically and ethically willing to accept in order to settle new worlds.  With regard to ASRI’s experiment roadmap, our intent is to start with smaller, simpler experiments that will garner us more data on individual stages of reproduction first using live mice and rats, with the hope of eventually moving on to complex and comprehensive experiments like MICEHAB.  Once we have a good plot of data over the course of many experiments, we can hopefully move on to primate relative studies to establish safe parameters for human trials.  I anticipate the small mammal experiments alone will take at least five years were we to launch our first mission at this very moment – though speed is often dependent on level of funding, as happens with most science.

SSP: If contraceptives are recommended to prevent conception during space tourism voyages, the paper calls for validation of the efficacy of these methods in off-world environments.  Do your plans for variable gravity experiments include such studies and how would you design the protocol?

AL: Well, the first important thing to remember is that contraceptives are known to fail occasionally on Earth – condoms can break (especially if used incorrectly), and even orally-taken birth control pills aren’t considered 100% effective. Currently ASRI doesn’t have plans for contraception studies because that’s further forward than we can reasonably forecast at this point. Frankly we need to establish medical parameters first regarding conception in space and know where the risk lines are before we implement birth control studies using humans. We have to take many small steps before we get there. Once we do have established limits for safe reproduction in space environments, we would look to operate any birth control studies within those parameters to determine efficacy. That way if the contraceptives do fail, we at least know the resulting pregnancy has a reasonable chance of success.

SSP: Should experiments on mammalian reproduction in variable gravity determine that fetal developmental or health issues arise after conception and gestation in less than 1g, do you think this may lead to a significant shift in the long-term strategy for space settlement (e.g. toward O’Neill type artificial gravity space settlements) if children are to be born and raised in space?

AL:  I certainly think so.  There’s a lot at stake here.  If we can’t safely birth and grow new generations of humans at a Martian gravity level (0.38 Earth G), then we’ve largely lost Mars as a destination for permanent multigenerational settlement. Fully grown adults can live and work down on the planet itself, but we’d need to come up with an alternate nearby solution for pregnant mothers and children growing up to certain age.  From an engineering perspective, artificial gravity space settlements like an O’Neill cylinder make the most sense to me personally, so long as there’s Earth-level radiation shielding and gravity, and you can recreate Earth-like environments within those structures.  During our conversation at ISDC I referred to it as an “Orbital Incubator” concept, though I’m of course not the first person to ever discuss something like that.

SSP: I appreciate you sharing your PhD Thesis with me. In that work you developed the Reproduction and Development in Off-Earth Environments (RADIO-EE) Scale to provide a metric that could help future researchers identify potential issues/threats to human reproduction in space environments, i.e. microgravity and radiation. Respecting your request that the images of the metric not be published at this time, qualitatively, the scale plots the different phases of reproduction, fetal development, live birth and beyond against levels of gravity or radiation in outer space environments encompassing the range from microgravity all the way up to 1g (and even higher). The scale displays green, amber, and red areas mapping safe, cautionary, and forbidden zones, respectively, dependent on location (e.g. Moon, Mars, free space, etc.). When I originally read your thesis I thought you included both gravity and radiation on the same chart but after our discussions I understand that they would have to be separated out. I also acknowledge that we have no data at this time and the metric is a work in process to be filled in as experiments are performed in space. Have you considered using three dimensions (gravity on x-axis, radiation on the y-axis, viability on the z-axis) and create a surface function for viability. Does that make sense?

AL: I’m totally with you on the 3D model scale (I’ve always thought of it like navigating a “tunnel” made up of green data points to reach the end of the reproductive cycle safely).  The scale was originally envisioned as separate graphs for Microgravity/Hypergravity and Radiation, but obviously we couldn’t combine those in 2D because those two different factors can vary wildly depending on where you’re physically located in the solar system/outer space in general.  So the best answer is to effectively plot green, amber, and red “zones” on each chart (again based on location), then make sure that wherever we’re trying to grow/raise offspring (of any Earth species) we’re keeping our expectant mothers and children in double-green zones (for both gravity, and radiation).  Now the third axis would actually be time (i.e. what point are you at in the reproductive cycle), with viability being determined by where all three axes meet in a green/amber/red zone.

I’d like to thank Alex for this informative discussion and look forward to further updates as his research progresses. We urgently need his insights to inform ethical policies and practices regarding reproduction for the space tourism industry in the short term, and eventually for having and raising healthy children wherever we decide to establish space settlements. Readers can listen to Alex describe his research live and talk to him in person when he appears on The Space Show currently scheduled for August 27.

The prospects for mining precious metals and structural materials from asteroids

Artist impression of an asteroid smelting operation. Credits: Bryan Versteeg / spacehabs.com

When humanity migrates out into the solar system we’ll need a variety of elements on the periodic table to build settlements and the infrastructure needed to support them such as solar power satellites. But before that future becomes a reality, there may be a near term market on Earth for precious metals sourced in space as transportation costs come down. There is also the added benefit of moving the mining industry off planet to preserve the environment. Could the asteroid belt provide these materials? Kevin Cannon, assistant professor at the Space Resources Program at the Colorado School of Mines describes the prospects for mining precious metals and building materials for space infrastructure asteroids in a recent paper in Planetary and Space Science. Coauthors on the paper Matt Gialich and Jose Acain, are CEO and CTO, respectively, at the asteroid mining company AstroForge which just came out of stealth mode last year.

The asteroids have accessible mining volume that exceeds that available on the Moon or Mars. This is because only the thin outer crust of these bodies is reachable by excavation, whereas the asteroids are small enough to be totally consumed resulting in higher accessible mining volume.

To-scale accessible mining volume of terrestrial bodies, calculated as the total volume for the asteroids (main belt mass of 2.39 x 1023 kg, mean bulk density of 2000 kg/m3), and as the volume for an outer shell 1.2 km in thickness for the Moon, Mercury, and Mars, equivalent to the deepest open pit mine on Earth. Note the combined volume of the near-Earth asteroids (~5 x 1012 m3) is too small to be visible at this scale. Figure 1 in paper. Credits K.M. Cannon et al.

The authors take a fresh look at available data from meteorite fragments of asteroids. Their analysis found that for Platinum Group Metals (PGMs), the accessible concentrations are higher in asteroids than ores here on Earth making them potentially profitable to transport back for use in commodity markets.

“Asteroids are a promising source of metals in space, and this promise will mostly be unlocked in the main belt where the Accessible Mining Volume of bodies greatly exceeds that of the terrestrial planets and
moons”

PGMs are indispensable in a wide range of industrial, medical, and electronic applications. Some examples of end-use applications include catalysts for the petroleum and auto industries (palladium and platinum), in pacemakers and other medical implants (iridium and platinum), as a stain for fingerprints and DNA (osmium), in the production of nitric acid (rhodium), and in chemicals, such as cleaning liquids, adhesives, and paints (ruthenium).

It has been pointed out by some analysts that flooding markets here on Earth with abundant supplies of PGMs from space will cause prices to plummet, but the advantage of reducing carbon emissions and environmental damage associated with mining activities may make it worth it. The authors also point out that there are probably various uses where PGMs offer advantages in material properties over other metals but are not being used because they are currently too expensive.

Asteroids are rich in other materials such as silicon and aluminum which would be economically more useful for in-space applications. As the authors point out, some companies are already planning for use of metals and manufacturing in space such as Redwire Corporation with their On-Orbit Servicing, Assembly and Manufacturing (OSAM) and Archinaut One, which will attempt to build structural beams in LEO. Another example mentioned in the paper has been covered by SSP: the DARPA NOM4D program with aspirations to develop technologies for manufacturing megawatt-class solar arrays and radio frequency antennas using space materials. Finally, another potential market for aluminum sourced in space is fuel for Neumann Thrusters (although spent upper stage orbital debris may provide nearer term supplies). And of course, silicon will be needed to fabricate photovoltaic cell arrays for space-based solar power.

AstroForge will test their asteroid mining technology on two missions this year. Brokkr-1, a 6U CubeSat just launched on the SpaceX Transporter 7 mission last April, will validate the company’s refinery technology for extracting metals by vaporizing simulated asteroid materials and separating out the constituent components. Brokkr-2 will launch a second spacecraft on a rideshare mission chartered by Intuitive Machines attempting their second Moon landing later this year. Brokkr-2 will hitch a ride and then fly on to a target asteroid located over 35 million km from Earth. The journey is expected to take about 11 months and will fly by the body and continue testing for two years to simulate a roundtrip mission.

The limits of space settlement – Pancosmorio Theory and its implications

Artist’s impression of the interior of an O’Neill Cylinder space settlement near the endcap. Credits: Don Davis courtesy of NASA

Its a given that space travel and settlement are difficult. The forces of nature conspire against humans outside their comfortable biosphere and normal gravity conditions. To ascertain just how difficult human expansion off Earth will be, a new quantitative method of human sustainability called the Panscosmorio Theory has been developed by Lee Irons and his daughter Morgan in a paper in Frontiers of Astronomy and Space Sciences. The pair use the laws of thermal dynamics and the effects of gravity upon ecosystems to analyze the evolution of human life in Earth’s biosphere and gravity well. Their theory sheds light on the challenges and conditions required for self restoring ecosystems to sustain a healthy growing human population in extraterrestrial environments.

“Stated simply, sustainable development of a human settlement requires a basal ecosystem to be present on location with self-restoring order, capacity, and organization equivalent to Earth.”

The theory describes the limits of space settlement ecosystems necessary to sustain life based on sufficient area and availability of resources (e.g. sources of energy) defining four levels of sustainability, each with increasing supply chain requirements.

Level 1 sustainability is essentially duplicating Earth’s basal ecosystem. Under these conditions a space settlement would be self-sustaining requiring no inputs of resources from outside. This is the holy grail – not easily achieved. Think terraforming Mars or finding an Earth-like planet around another star.

Level 2 is a bit less stable with insufficient vitality and capacity resulting in a brittle ecosystem that is subject to blight and loss of diversity when subjected to disturbances. Humans could adapt in a settlement under these conditions but would required augmentation by “…a minimal supply chain to replace depleted resources and specialized technology.”

Level 3 sustainability has insufficient area and power capacity to be resilient against cascade failure following disturbances. In this case the settlement would only be an early stage outpost working toward higher levels of sustainability, and would require robust supplemental supply chains to augment the ecosystem to support human life.

Level 4 sustainability is the least stable necessitating close proximity to Earth with limited stays by humans and would require an umbilical supply chain supplementing resources for human life support, and would essentially be under the umbrella of Earth’s basal ecosystem. The International Space Station and the planned Artemis Base Camp would fall into this category.

Understanding the complex web of interactions between biological, physical and chemical processes in an ecosystem and predicting early signs of instability before catastrophic failure occurs is key. Curt Holmer has modeled the stability of environmental control and life support systems for smaller space habitats. Scaling these up and making them robust against disturbances transitioning from Level 2 to 1 is the challenge.

How does gravity fit in? The role of gravity in the biochemical and physiological functions of humans and other lifeforms on Earth has been a key driver of evolution for billions of years. This cannot be easily changed, especially for human reproduction. But even if we were able to provide artificial gravity in a rotating space settlement, the authors point out that reproducing the atmospheric pressure gradients that exist on Earth as well as providing sufficient area, capacity and stability to achieve Level 1 ecosystem sustainability will be very difficult.

Peter Hague agrees that living outside the Earth’s gravity well will be a significant challenge in a recent post on Planetocracy. He has the view, held by many in the space settlement community, that O’Neill colonies are a long way off because they would require significant development on the Moon (or asteroids) and vast construction efforts to build the enormous structures as originally envisioned by O’Neill. Plus, we may not be able to easily replicate the complexity of Earth’s ecosystem within them, as intimated by the Panscosmorio Theory. In Hague’s view Mars settlement may be easier.

Should we determine the Gravity Rx? Some space advocates believe that knowledge of this important parameter, especially for mammalian reproduction, will inform the long term strategy for permanent space settlements. If we discover, through ethical clinical studies starting with rodents and progressing to higher mammalian animal models, that humans cannot reproduce in less than 1G, we would want to know this soon so that plans for the extensive infrastructure to produce O’Neill colonies providing Earth-normal artificial gravity can be integrated into our space development strategy.

Others believe why bother? We know that 1G works. Is there a shortcut to realizing these massive rotating settlements without the enormous efforts as originally envisioned by Gerard K. O’Neill? Tom Marotta and Al Globus believe there is an easier way by starting small and Kasper Kubica’s strategy may provide a funding mechanism for this approach. Given the limits of sustainability of the ecosystems in these smaller capacity rotating settlements, it definitely makes sense to initially locate them close to Earth with reliable supply chains anticipated to be available when Starship is fully developed over the next few years.

Companies like Gravitics, Vast and Above: Space Development Corporation (formally Orbital Assembly Corporation) are paving the way with businesses developing artificial gravity facilities in LEO. And last week, Airbus entered the fray with plans for Loop, their LEO multi-purpose orbital module with a centrifuge for “doses” of artificial gravity scheduled to begin operations in the early 2030s. Panscosmorio Theory not withstanding, we will definitely test the limits of space settlement sustainability and improve over time.

Listen to Lee and Morgan Irons discuss their theory with David Livingston on The Space Show.

Autonomous conversion of asteroids into rotating space settlements

Artist impression of a rotating space settlement constructed from an asteroid. Credits: Bryan Versteeg, spacehabs.com

When Gerard K. O’Neill first proposed building enormous rotating space settlements at the Earth-Moon Lagrange points back in the 1970s he envisioned many space shuttle flights to launch the initial equipment and people into space. He thought that mass drivers placed on the Moon would be an efficient and cost effective mechanism for lofting copious amounts of lunar regolith needed for radiation shielding to protect colonists aboard the settlements. Alas, the economics of the shuttle did not work out back then, as reusability (among other things) was not ready for prime time, making launch costs a show stopper. Also, O’Neill thought that hundreds of people would be working under weightless conditions in space to fabricate the settlements. This was problematic because of the health hazards of exposure to radiation and microgravity.

All three problems can be solved according to David W. Jensen in an article posted on the ArXiv server. He envisions restructuring an asteroid into a spin gravity space settlement using self replicating robots to process asteroid materials in situ. High launch costs would be solved with a single modest-size probe containing a small number of seed robots that fashion more robots, tools and equipment. This approach bootstraps the colony fabrication through self replicating machines and in situ resource utilization.

“The restructuring process improves the productivity using self-replication parallelism and tool specialization.”

By removing humans from the initial asteroid processing activities, health risks from radiation and the deleterious effects of microgravity would be eliminated. Restructuring of the asteroid would take about a decade, after which colonists would have a rotating space settlement the size of a Stanford Torus providing Earth normal gravity and a safe living space shielded from radiation, ready for buildout and eventual occupation.

Cutaway view of a Stanford Torus space settlement. Credits: Rick Guidice / NASA

The key to this approach is self replication of robots delivered in the initial seed payload which significantly reduces costs by launching only one rocket to the target asteroid. The first machines sent are called replicators, or spiders for short. Four of these spiders with a minimum of supplies use the raw materials of the asteroid to make thousands of copies of themselves plus additional helper machines (tools and equipment). The spiders and helpers cooperate to produce end products of construction materials and the colony structures.

Jensen does not assume total self-replication, meaning that the robots do not need to make complete copies of themselves. A small percentage of more complex mechanisms such as microprocessors are provided in the initial payload as supplemental “vitamins” to finish out the machines. The intent is to minimize the need for humans in the initial construction phase. The objective is to fabricate a basic scaffolding for a rotating space settlement with access to an abundant storehouse of volatiles and metals. The final enclosed structure would then support migration of colonists who would complete construction and add more advanced manufacturing technologies such as solar cell production and microelectronics. As SSP has explained previously, complete closure of self-replicating machines is very challenging, but is not needed in this case.

The technology has wide applications and could be applied to Earth’s desserts, on the surface of the Moon or Mars, or even on the satellites of Jupiter and Saturn.

“We plan to apply and study these concepts for use in lunar, Titan, and Martian environments.”

Jensen’s restructuring process could complement or be combined with other asteroid mining architectures such as the University of Rochester’s approach which builds spin gravity cities starting with a carbon fiber collapsible scaffolding completely encapsulating the target asteroid. As the process matures it could be applied to even larger bodies such as the asteroid Ceres eventually combining settlements into a mega satellite community as envisioned by Pekka Janhunen.

“The equipment and process are scalable and … create a
space station structure that can support a population of nearly
one million people.”

Spin gravity cities fabricated from Near Earth Asteroid rubble piles

A cylindrical, spin gravity space settlement constructed from asteroid rubble like that from the Near Earth Asteroid Bennu. The regolith provides radiation shielding contained by a rigid container beneath the solar panels. The structure is spun up to provide artificial gravity for people living on the inner surface. Credits: Peter Miklavčič et al.*

Scientists and engineers* at the University of Rochester have conceived of an innovative way to capture a Near Earth Asteroid (NEA) and construct a cylindrical space colony using it’s regolith as shielding. In a paper in Frontiers in Astronomy and Space Sciences they propose a spin gravity habitat called Bennu after the NEA of the same name. Readers will recall that NASA’s OSIRIS-REx spacecraft launched in September 2016, traveled to Bennu, collected a small sample in October 2018 and is currently in transit back to Earth where the sample return capsule will reenter the atmosphere and parachute down in Utah later this year.

Near Earth Asteroid Bennu imaged by the spacecraft OSIRIS-REx. Credit: NASA Goddard Space Flight Center

It would be ideal if an asteroid could be hollowed out for radiation shielding and spun up to create artificial gravity. However, it is shown in this paper that this would not work for larger solid rock asteroids because they don’t have the tensile strength to withstand the rotational forces and smaller rubble pile asteroids (like Bennu) would fly apart because they are too loosely conglomerated.

The problem is solved by containing the asteroid in a carbon fiber collapsible scaffolding that initially has the same radius of the asteroid. As the container is spun up, the centrifugal force will cause the disintegrating rubble to push open the expandable cylinder to its final diameter.

“…a thick layer of regolith is created along the interior surface of this structure which forms a shielded interior volume that can be developed for human occupation.”

The mechanism to initiate the rotation of the structure is interesting. Solar arrays on the outer surface would power mass driver cannons which eject rubble tangentially exerting torque to produce spin.

Detailed engineering analysis and simulations are performed to calculate the stresses on a Bennu sized asteroid to create a cylindrical space colony 3 kilometers in diameter. This structure would have a shielded livable space of 56 square kilometers, an area roughly equivalent to Manhattan.

The authors conclude that the physics of harvesting small asteroids and converting them into rotating space settlements is feasible. They note that this approach would cost less and be easier from an engineering standpoint then fabrication of classic O’Neill cylinders. Concepts for asteroid capture and utilization have already been covered on SSP such as TransAstra’s Queen Bee and SHEPHERD.

The University of Rochester News Center provided a good write up of the paper last December.


* Authors of cited paper: Miklavčič PM, Siu J, Wright E, Debrecht A, Askari H, Quillen AC and Frank A – (2022) Habitat Bennu: Design Concepts for Spinning Habitats Constructed From Rubble Pile NearEarth Asteroids. Front. Astron. Space Sci. 8:645363. doi: 0.3389/fspas.2021.645363

Mars as breadbasket for the outer solar system

Artist’s rendering of a farming settlement on Mars. Credits: HP Mars Home Planet Rendering Challenge via International Business Times.

Space settlement will eventually require space farming to feed colonists and to provide life support. It’s clear that we will replicate our biosphere wherever we go. In that spirit, Bryce L. Meyer envisions Mars as the breadbasket of the outer solar system. In a presentation at Archon 45, a science fiction and fantasy convention held annually by St. Louis area fans, he makes the case for why the fourth planet would be the ideal spot to grow crops and feed an expanding population as part of the roadmap to agriculture in space.

Carbon dioxide and subsurface water ice are plentiful on Mars, critical inputs for crop photosynthesis. There is also evidence of lava tubes there which could provide an ideal growing environment protected from radiation, micrometeorite bombardment and temperature extremes. The regolith should provide good nutrients and there is already research on methods to filter out perchlorates, a toxic chemical compound in the Martian soil.

Image of Lava tubes on the surface of Mars as photographed by ESA’s Mars Express spacecraft. Credits: ESA/DLR/FU Berlin/G Neukum / NewScientist

Another advantage that Mars holds as a food production hub for the asteroids and beyond is its placement further out in the solar system. Since it is higher up in the sun’s gravity well, Meyer calculates that it would take less than 43% of the fuel needed to transport goods from Mars outward than from Earth. He even suggests that with its lower gravity and recent advancements in materials research, a space elevator at Mars could be economically feasible to cheaply and reliably transport foodstuff off the planet.

Meyer keeps a webpage featuring space agriculture, terraforming, and closed cycle microgravity farming where he poses the question “Why settle space?” I like his answer: “Trillions of Happy Smiling Babies!!!”

Basic input/output diagram of an environmental control and life support system like what would be expected in a space farm. Credits: Bryce L. Meyer

Meyer is the founder and CEO of Cyan React, LLC, a startup that designs compact photobioreactors and provides expertise in closed-cycle farming and life support especially for space settlement and space habitats. He is also a National Space Society Space Ambassador doing his part to educate the public about the potential benefits to humanity through the use of the bountiful resources in space. In a presentation at this year’s International Space Development Conference, he describes his research on bioreactors explaining how settlers will grow food and recycle waste sustainably on the high frontier.

Diagram depicting the flow of materials in a closed space farm habitat utilizing bioreactors. Credits: Bryce L. Meyer

Complete closure and stability of an environmental control and life support system (ECLSS) is challenging and not without limitations. As launch and space transportation costs come down in the near future and off-Earth supply chains become more reliable, complete closure will not be required at least initially. In situ resource utilization will provide replacement of some ECLSS consumables where available for colonists to live off the land. As missions go deeper into space reaching the limits of supply chain infrastructure and even out to the stars, closure of habitat ECLSS and resource planning will become more important. Meyer has done the math for farms in space to provide food and air for trillions of smiling babies…and their families as they move out into the solar system.

Dennis Wingo’s strategy for development of cislunar space and beyond

Image credit: NASA/Goddard/Arizona State University

The Cislunar Science and Technology Subcommittee of the White House Office Science and Technology Policy Office (OSTP) recently issued a Request for Information to inform development of a national science and technology strategy on U.S. activities in cislunar space.

Dennis Wingo provided a response to question #1 of this RFI, namely what research and development should the U.S. government prioritize to help advance a robust, cooperative, and sustainable ecosystem in cislunar space in the next 10 to 50 years?

In a prolog to his response Wingo reminds us that historically, NASA’s mission has focused narrowly on science and technology.  What is needed is a sense of purpose that will capture the imagination and support of the American people.    In today’s world there seems to be more dystopian predictions of the future than positive visions for humanity.  We seem to be dominated by fear of “…doom and gloom scenarios of the climate catastrophe, the degrowth movement, and many of the most negative aspects of our current societal trajectory.”  This fear is manifested by what Wingo defines as a “geocentric” mindset focused primarily within the material limitations of the Earth and its environs.

“The question is, is there an alternative to change this narrative of gloom and doom?”

He recommends that policy makers foster a cognitive shift to a “solarcentric” worldview: the promise of an economic future of abundance through utilization of the virtually limitless resources of the Moon, Asteroids, and of the entire solar system.  An example provided is to harvest the resources of the asteroid Psyche which holds a billion times the minable metal on Earth, and to which NASA had planned on launching an exploratory mission this year but had to delay it due to late delivery of the spacecraft’s flight software and testing equipment.

Artist rendering of NASA’s Psyche Mission spacecraft.  Credits: NASA/JPL-Caltech/Arizona State Univ./Space Systems Loral/Peter Rubin

Back to the RFI, Wingo has four recommendations that will open up the solar system to economic development and address many of the problems that cause the geocentrists despair. 

First, we should make the Artemis moon landings permanent outposts with year long stays as opposed to 6 day “camping trips”. This should be possible with resupply missions by SpaceX as they ramp up Starship launch rates (assuming the launch vehicle and lander are validated in the same timeframe, which seems reasonable). Next, we need power and lots of it – on the order of megawatts.  This should be infrastructure put in place by the government to support commerce on the Moon.  By leveraging existing electrical power standards and production techniques, large scale solar power facilities could be mass produced at low cost on Earth and shipped to the moon before the capability of in situ utilization of lunar resources is established.  Some companies such as TransAstra already have preliminary designs for solar power facilities on the Moon.

Which brings us to ISRU.  The next recommendation is to JUST DO IT.  This technology is fairly straightforward and could be used to split oxygen from metal oxides abundant in lunar regolith to source air and steel.  Pioneer Astronautics is already developing what they call Moon to Mars Oxygen and Steel Technology (MMOST) for just this application.

Conceptual illustration of the Lunar OXygen In-situ Experiment (LOXIE) Production Prototype. Credits: Mark Berggren / Pioneer Astronautics

And lets not forget the wealth of in situ resources that could be unlocked via synthetic geology made possible by Kevin Cannon’s Pinwheel Magma Reactor.

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

Of course there is water everywhere in the solar system just waiting to be harvested for fuel and life support in a water-based economy.

Illustration of an ice extraction concept for collection of water on the Moon. Credits: George Sowers / Colorado School of Mines

Wingo’s final recommendation is industrialization of the Moon in preparation for the settlement of Mars followed by the exploration of the vast resources of the Asteroid Belt.  He makes it clear that this is more important than just a goal for NASA, which has historically focused on scientific objectives, and should therefore be a national initiative.

“…for the preservation and extension of our society and to preclude the global fight for our limited resources here.”

With the right vision afforded by this approach and strong leadership leading to its implementation, Wingo lays out a prediction of how the next fifty years could unfold. By 2030 over ten megawatts of power generation could be emplaced on the Moon which would enable propellant production from the pyrolysis of metal oxides and hydrogen production from lunar water.  This capability allows refueling of Starship obviating the need to loft propellent from Earth and thereby lowering the costs of a human landing system to service lunar facilities.  From there the cislunar economy would begin to skyrocket.

The 2040s see a sustainable 25% annual growth in the lunar economy with a burgeoning Aldrin Cycler business to support asteroid mining and over 1000 people living on the Moon.

By the 2050s, fusion reactors provide power and propulsion while the first Ceres settlement has been established providing minerals to support the Martian colonies.

“The sky is no longer the limit”

By sowing these first seeds of infrastructure a vibrant cislunar economy will enable sustainable settlement across the solar system. A solarcentric development mythology may be just what is needed to become a spacefaring civilization.

Artist’s concept of an O’Neill space colony. Credits: Rachel Silverman / Blue Origin

Highlights from the International Space Development Conference

Conceptual illustration of Mag Mell, a rotating space settlement in the asteroid belt in orbit around Ceres – grand prize winner of the NSS Student Space Settlement Design Contest. Credits: St. Flannan’s College Space Settlement design team*

In this post I summarize a few selected presentations that stood out for me at the National Space Society’s International Space Development Conference 2022 held in Arlington, Virginia May 27-29.

First up is Mag Mel, the grand prize winner of the NSS Student Space Settlement design contest, awarded to a team* of students from St. Flannan’s College in Ireland. This concept caught my eye because it was in part inspired by Pekka Janhunen’s Ceres Megasatellite Space Settlement and leverages Bruce Damer’s SHEPHERD asteroid capture and retrieval system for harvesting building materials.

The title Mag Mell comes from Irish mythology translating to “A delightful or pleasant plain.” These young, bright space enthusiasts designed their space settlement as a pleasant place to live for up to 10,000 people. Each took turns presenting a different aspect of their design to ISDC attendees during the dinner talks on Saturday. I was struck by their optimism for the future and hopeful that they will be representing the next generation of space settlers.

Robotically 3D printed in-situ, Mag Mell would be placed in Ceres equatorial orbit and built using materials mined from that world and other bodies in the Asteroid Belt. The settlement was designed as a rotating half-cut torus with different angular rotation rates for the central hub and outer rim, featuring artificial 1G gravity and an Earth-like atmosphere. Access to the surface of the asteroid would be provided by a space elevator over 1000 km in length.


* St. Flannan’s College Space Settlement design team: Cian Pyne, Jack O’Connor, Adam Downes, Garbhán Monahan, and Naem Haq


Conceptual illustration of a habitat on Mars constructed from self-replicating greenhouses. Credits: GrowMars / Daniel Tompkins

Daniel Tompkins, an agricultural scientist and founder of GrowMars, presented his Expanding Loop concept of self replicating greenhouses which would be 3D printed in situ on the Moon or Mars (or in LEO). The process works by utilizing sunlight and local resources like water and waste CO2 from human respiration to grow algae for food with byproducts of bio-polymers as binders for 3D printing blocks from composite concretes. Tompkins has a plan for a LEO demonstration next year and envisions a facility eventually attached to the International Space Station. He calculates that a 4000kg greenhouse could be fabricated from 1 year of waste CO2 generated by four astronauts. An added bonus is that as the greenhouse expands, an excess of bioplastic output would be produced, enabling additional in-space manufacturing.

Diagram depicting GrowMars Expanding Loop algae growing process to create greenhouse blocks and byproducts such as proteins and fertilizer. Credits: GrowMars / Daniel Tompkins.

Illustration of a portion of the Spacescraper tethered ring from the Atlantis Project. Credits: Phil Swan

Phil Swan introduced the Atlantis Project, an effort to create a permanent tethered ring habitat at the limit of the Earth’s atmosphere, which he calls a Spacescraper.  The structure would be placed on a stayed bearing consisting of two concentric rings magnetically attached and levitated up to 80 km in the air.  In a white paper available on the project’s website, details of the force vectors for levitation of the device, the value proposition and the economic feasibility are described. As discussed during the talk at ISDC, potential applications include:

  • Electromagnetic launch to space
  • Carbon neutral international travel
  • Evacuated tube transit system
  • Astronomical observatories
  • Communication and internet
  • Solar energy collection for electrical power
  • Space tourism
  • High rise real estate

Phil Swan will be coming on The Space Show June 21 to provide more details.


Conceptual illustration of a Mars city design with dual centrifuges for artificial gravity. Credits: Kent Nebergall

Finally, the Chair of the Mars Society Steering committee and founder of MacroInvent Kent Nebergall, gave a presentation on Creating a Space Settlement Cambrian Explosion. That period, 540 million years ago when fossil evidence goes from just multicellular organisms to most of the phyla that exist today in only 10 million years, could be a metaphor for space settlement in our times going from extremely slow progress to a quick expansion via every possible solution. Nebergall suggests that we may be on the verge of a similar growth spurt in space settlement and proposes a roadmap to make it happen this century.

He envisions three settlement eras beginning with development of SpaceX Starship transportation infrastructure transitioning to robust cities on Mars with eventual para-terraforming of that planet. He also has plans for how to overcome some of the most challenging barriers – momentum and money. Stay tuned for more as Kent has agreed to an exclusive interview on this topic in a subsequent post on SSP as well as an appearance on The Space Show July 10th.

NewSpace features the dawn of the age of space resources

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 Pinwheel Magma Reactor for synthetic geology and plans for feeding millions of people on Mars.