Concept illustration of Offworld’s Prospector 1 Mobile Excavator. Credits: Dallas Bienhoff / Offworld, Inc.
At the intersection of AI, swarm robotics and mining technology lies the key to sustainable, affordable space development. Offworld, Inc. is on the cutting edge of this frontier with their suite of diverse robot species that when coordinated with collective intelligence, will enable sustainable in situ resource utilization (ISRU) thereby lowering the cost of establishing settlements on the Moon and beyond, while kickstarting a thriving off Earth economy. In a presentation to the Future In-Space Operations (FISO) Telecon on July 24, Space Systems Architect Dallas Bienhoff described Offworld’s plans for an ambitious demonstration mission called Prospector 1.
In April 2023, OffWorld Europe entered into an agreement with the Luxembourg Space Agency to collaborate on a Lunar ISRU exploration program commissioned by the European Space Agency. The multi-year initiative will develop a processing system focused on harvesting and utilizing lunar ice resources. The program will develop a Lunar Processing Module (LPM) to be integrated into a mobile excavator that will be launched to Moon’s south pole on the Prospector 1 mission currently scheduled for late 2027. The goal of Prospector 1 is to demonstrate the capability of processing icy lunar regolith to produce oxygen and hydrogen. The LPM when loaded with icy regolith will process the lunar soil to extract water, then via electrolysis produce oxygen and hydrogen. The module’s hopper is designed to receive up to 50 kg of regolith and batch process 2.5kg/hour. The unit will be housed on a mobile excavator massed at 2500 kg. Offworld has already completed TRL4 testing on the LPM in their Luxembourg office.
The company is exploring a variety of options for generation of power for the mission. Of course landers provide some minimal power but not nearly enough for processing lunar regolith. One promising system under consideration is the Vertical Solar Array Technology (VSAT) under development by Astorbotic which will provide 10kw of power (only in sunlight). But wait, there’s more! Astrobotic announced this month that they were just awarded a Small Business Innovation Research (SBIR) award by NASA to develop a larger version of the array called VSAT-XL capable of delivering 50kw. Designed to track the sun, VSAT is ideal for location at the lunar south pole where the sun’s rays are at very low elevation and provide semi-permanent illumination on the rims of permanently shadowed craters.
Comparison of relative sizes of the two VSAT solar arrays. Credit: Astrobotic
Another innovative alternative is a power source called the Nuclear Thermionic Avalanche Cell (NTAC ) under development by Tamer Space, a company providing a range of power and construction resources for settlements on the Moon, the Cislunar economy and sustainable pioneering of Mars. The device is an electrical generator that converts nuclear gamma-ray photons directly to electric power in a compact, reliable package with high power density capable of long-life operation without refueling. NTAC can provide higher power levels (e.g. starting at 100kw) and is not dependent on the sun to enable operations through the lunar night should Offworld elect to locate their facility far from the Moon’s poles or in permanently shadowed regions. Tamer described their technology at the 2023 Space Resources Roundtable
Image of a research prototype of the Nuclear Thermionic Avalanche Cell: Credit: Tamer Space
After Propector 1, Offworld’s follow on plans envision a second Prospector 2 to be launched in the 2029 timeframe. This mission will ramp up capability to include multiple robot species such as an excavator, hauler, and processor. In addition, liquefaction will be added to the process stream (not just gaseous products) and pilot plant capabilities will be demonstrated to reduce risk for the next mission. In 2031, a formal pilot plant will be established with multiple excavators and haulers. The facility will have a fixed processing plant and storage facilities capable of producing tons of water, oxygen, and hydrogen. By the end of 2034, OffWorld plans to launch an industrial scale ISRU plant with output of 100s of tons of volatiles, elements and bulk regolith per year.
Bienhoff said at the conclusion of his presentation that Offworld’s long term vision for lunar operations include: “Industrial scale ISRU, 10s – 100s of tons of product per year – by product [I mean] that’s processed regolith, that’s oxygen, that’s hydrogen, that’s water, that’s perhaps metals. We plan to monetize or use every gram we excavate. That’s a tall order, but in order to have a thriving lunar community, we need to produce as much as we can on the Moon, for the Moon, before we think about exporting from the Moon.”
Conceptual illustration depicting the design features of a Korean Space Solar Power Satellite (K-SSPS) Credits: Joon-Min Choi, Su-Jin Choi, Sang-Hwa Yi via Creative Commons License CC by 4.0
Researchers from the Korea Aerospace Research Institute (KARI) and the Korea Electrotechnology Research Institute (KERI) describe a concept for a Korean Space Solar Power Satellite in a new publication called the Journal of Space Solar Power and Wireless Transmission. Dubbed K-SSPS, its components would be launched with reusable rockets, robotically assembled and tested in LEO, then boosted to geostationary orbit (GEO) using solar electric thrusters powered by its own solar cell array.
The baseline conceptual design for K-SSPS provides 2GW of delivered power to the ground collected by a 4km diameter rectenna located in the Demilitarized Zone. There is sufficient space in this region for 60 rectennas of this size for a total collected power of 120 GW. In terms of electricity generation, such a system would provide a terawatt-hour of electricity per year which exceeds South Korea’s electricity consumption in 2021.
This study also addresses disposal of the system after its useful life estimated to be about three decades, Since such massive systems spanning an area measuring several square kilometers would present a rather large cross section increasing the risk of collision with other decommissioned satellites in the usual graveyard orbit located 235 km above GEO, the authors propose a novel but controversial approach: controlled crash landing the spent satellite in a safe zone on the far side of the Moon. This would enable future colonies on the Moon to harvest these valuable Earth-sourced materials from the impact zone, recycling them into useful commodities to help sustain lunar operations. Care would have to be taken to ensure that the structure is guided to a designated area far from established infrastructure, most of which (if not all) would be located on the near side facing Earth. Not considered in the study was recycling and/or repurposing the K-SSPS materials in space using material processing technology like Cislunar Industries’ Modular Space Foundry (previously Microspace Foundry).
South Korea’s space agency, the Korea Aerospace Research Institute (KARI), has set a goal of a test system deployment in LEO by 2040, with a full scale system in GEO by 2050. Since this effort will take considerable development time and significant financial investment, KARI plans a small-scale two-satellite pilot system demonstration in LEO within the next decade to validate the wireless power transmission technology and the deployment mechanisms. The pilot system, which was described in a paper presented at the 73rd International Astronautical Congress in September 2022, will be placed in a sun synchronous orbit and features a solar panel equipped antenna array beaming power to a receiver satellite 100m away, in a sun synchronous orbit.
Diagram depicting the operational concepts planned over the mission life of the KARI pilot space solar power demonstration. Credits: Joon-Min Choi, Su-Jin Choi, Sang-Hwa Yi via Creative Commons License CC by 4.0
KARI and KIRI have described their case studies on a space solar power program as a renewable energy option for Korea to help address global efforts to achieve net zero greenhouse gas emissions by 2050. This paper summarizes their concept design for a 2GW space solar satellite highlighting gaps in the economic and technological knowledge needed for success, proposed a responsible and sustainable disposal method, and outlined an achievable architecture for a near term pilot demonstration within a decade. Korea joins other global development efforts that SSP has been following with their own unique approach to space-based solar power (SBSP).
However, doubters have been surfacing recently highlighting the significant engineering and economic challenges that need to be addressed for SBSP to be competitive with ground-based renewable energy sources and backup storage systems, the technology of which are rapidly developing and improving. One skeptic, former European Space Agency engineer Henri Barde, published an article in IEEE Spectrum arguing that among other things, designers will have a significant challenge shaping and aiming the microwave beam of a kilometer-scale phased array antennae. In his opinion, this and other engineering obstacles will not be solved until fusion energy will be commercially available. In a rebuttal on LinkedIn, CEO of SBSP startup Virtus Solis John Bucknell responded that his company has proprietary software that can simulate greater than 2km transmission apertures and that SBSP is in the engineering phase while fusion is still in R&D, the complexity of which makes capital and operating costs a big unknown for commercialization.
NASA has yet again kicked the can down the road, claiming in their most recent study that expected greenhouse gas emissions and the cost of space hardware for current design options will be on a par with existing renewable electricity technologies and therefore recommends further study to close several technology gaps for SBSP to make economic sense. The next few years will be critical for engineering testing, not only for Korea’s pilot satellite, but Virtus Solis‘s in-space plans and Northrup Grumman’s end-to-end test in 2025 of their Space Solar Power Incremental Demonstrations and Research prototype system. Once in-space prototype testing demonstrates sufficient feasibility to retire technical risks, venture capital investors may feel comfortable funding subsequent operational phases toward profitable commercialization.
Artist’s depiction of the NASA Volatiles Investigating Polar Exploration Rover (VIPER) locating and assessing the concentration of ice and other resources near the Moon’s South Pole. Credits: NASA / Daniel Rutter
NASA and space settlement advocates are justifiably excited about resources on the Moon, especially water ice known to be present in permanently shadowed regions (PSR) at the lunar poles, because of it’s potential as a source of oxygen and fuel that could be sourced in situ saving the costs of transporting these valuable commodities from Earth. But how much ice is actually available, accessible and can be processed into useable commodities? In other words, in terms defined by the U.S. Geological survey, what are the proven reserves? A reserve is a subset of a resource that can be economically and legally extracted.
By way of background, under NASA’s Moon to Mars (M2M) Architecture where the agency is defining a roadmap for return to the Moon and then on to the Red Planet, an Architecture Definition Document (ADD) with the aim of creating an interoperable global lunar utilization infrastructure was released last year. The goals articulated in the document are to enable the U.S. industry and international partners to maintain continuous robotic and human presence on the lunar surface for a robust lunar economy without NASA as the sole user, while accomplishing science objectives and testing technology that will be needed for operations on Mars.
Of the nine Lunar Infrastructure (LI) goals in the ADD, LI-7 addresses the need to demonstrate in situ resource utilization (ISRU) through delivery of an experiment to the lunar South Pole, the objective of which would be demonstrating industrial scale ISRU capabilities in support of a continuous human lunar presence and a robust lunar economy. LI-8 aims to demonstrate a) the capability to transfer propellant from one spacecraft to another in space; b) the capability to store propellant for extended durations in space and c) the capability to store propellant on the lunar surface for extended durations – defining the objective to validate technologies supporting cislunar orbital/surface depots, construction and manufacturing maximizing the use of in-situ resources, and support systems needed for continuous human/robotic presence.
To accomplish these goals NASA initiated a series of Lunar Surface Science Workshops starting in 2020. The results of workshops 17 and 18 held in 2022 were summarized last January in a paper by Neal et al. in Acta Astronautica and discussed recently at a Future In-Space Operations (FISO) Telecon on 2/14/2024 in a presentation by Lunar Surface Innovation Consortium (LSIC) members Karl Hibbitts, Michael Nord, Jodi Berdis and Michael Miller. These efforts identified a conundrum: there is not enough data to establish how much proven reserves of lunar water ice are available to inform economically viable plans for ISRU on the Moon. Thus, a resource prospecting campaign is needed to address this problem. International cooperation on such an initiative, perhaps in the context of the Artemis Accords, makes sense to share costs while enabling the signatories of the Accords (39 as of this post) to realize economic benefits from commerce in a developing cislunar economy.
The campaign concept proposes a 3-tiered approach. First, confirming ice is present in the PSRs near potential Artemis landing sites – this could be done by low altitude orbital reconnaissance using neutron spectroscopy, radar and other techniques. Next, surface rovers already on the drawing board such as the Volatiles Investigating Polar Exploration Rover (VIPER), would be deployed to locate specific reserves.
Finally, detailed characterization of the reserve using rovers leveraging capabilities learned from VIPER and optimized for reconnaissance in the PSRs. Some technological improvements would be needed in this final phase to address power and long duration roving under the expected extreme conditions. Nuclear power sources and wireless power beaming from solar arrays on the crater rims, both requiring further development, could solve these challenges. This technology will be directly transferrable to equipment needed for excavation, which will face the same power and reliability hurdles in the ultra cold darkness of the PSRs.
As mentioned in the FISO presentation and pointed out by Kevin Cannon in a previous post by SSP, how water ice is distributed in lunar regolith “endmembers” is a big unknown and could be quite varied. Characterization during this last phase is paramount before equipment can be designed and optimized for economic extraction.
Artist’s impression of different types of lunar water ice / regolith endmembers, characterization of which will be required before extraction methods and equipment can be validated. Credits: Lena Jakaite / strike-dip.com / Colorado School of Mines
The authors of the paper acknowledge that coordinating an international effort will be difficult but involving all stakeholders will foster cooperation and shape positive legal policy within the framework of the Artemis Accords to comply with the Outer Space Treaty.
From the conclusion of the paper:
“If the reserve potential is proven, the benefits to society on Earth would be immense, initially realized through job growth in new space industries, but new technologies developed for sending humans offworld and commodities made from lunar resources could have untold important benefits for society back here.”
George Sowers, whose research was referenced in the paper and covered by SSP, believes that “Water truly is the oil of space” that will kickstart a cislunar economy. Once reserves of lunar water ice are proven to exist through a prospecting campaign and infrastructure is placed to enable economically feasible mining and processing for use as rocket fuel and oxygen for life support systems, technology improvements and automation will reduce costs. If it can be made competitive with supply chains from Earth lunar water will be the liquid gold that opens the high frontier.
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.
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.”
“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
“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.”
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
Artist concept of a Mars settlement serviced by SpaceX Starships. Credits: SpaceX
Before there are large numbers of settlers on Mars people will live in small isolated outposts subject to the vagaries of restrained human habitats under extreme conditions. To ensure survival and sustainability it will be important to select crews that have psychological profiles with the capacity to manage adverse conditions, elevated risk or unplanned disasters. A group of researchers has studied this problem for a hypothetical mining colony on Mars using Agent-Based Modeling. A preprint paper describing their research has been posted by Anamaria Bereaon of George Mason University on the arXiv server.
Agent-Based Modeling (ABM) is a computational model for simulating the interactions of people or other collective entities (i.e. autonomous agents) either individually or in groups to understand their behavior under specified conditions. Application of ABM could be useful to predict the ecological and demographic factors required for sustainable resource-management in a restricted human settlement off Earth.
For this study human profiles were modeled after personality traits gleaned from scholarly research on the psychology of teams in extreme isolation and high stress environments such as aboard submarines, stays in Antarctica, and military deployments in war theaters. Success of individuals and teams under these conditions is dependent on coping capacity, i.e. the ability of people to use their skills and available resources to manage risk or disasters under adverse conditions.
The agents were selected based on four profiles used by NASA to screen and evaluate subjects in isolated and extreme environments. These individuals fall into the following categories, listed in decreasing order of coping capacity as measured on a standardized scale:
Agreeables: low competitiveness and aggressiveness, and not fixated on stringent routines
Socials: medium competitiveness, extroverted, not fixated on stringent routines
Reactives: medium competitiveness, competitive interpersonal orientation, fixated on stringent routines
Neurotics: highly competitive and aggressive interpersonal characteristics, difficulty adapting to boredom or change in routines
Next, the subjects were assigned management and engineering skills associated with the anticipated roles and specialized abilities needed for 30 month crewed mission to Mars. It was assumed that a mining colony had already been established to supply minerals back to Earth and that the facility would get it’s power from a fission nuclear reactor. The settlement would start out with sufficient air, water and food but would depend on supply lines from Earth for resupply. The goal of the ABM model was to apply stressors to the agents such as random resupply shuttle accidents or habitat disasters to assess interactions and skill use among the different personality types to gain insights on which category would be more enduring for the establishment of a stable colony.
The mining colony was modeled using NetLogo 6.2. NetLogo is an open source modeling environment designed for simulating natural and social interactions. The programming language is ideal for modeling complex system evolving over time.
An initial number of occupants was specified up to a maximum of 152 divided equally into the four personality types. The mining operations were then allowed to proceed over multiple time increments of one week where colonists move about the settlement, form teams to produce resources, consume supplies, interact with each other, and sleep. Health is assigned a numerical variable and can be affected by lack of sleep or consuming more resources than what is planned to be produced. Stressors were introduced such as Earth supply line disruptions or habitat disasters. Colonists partner with each other to produce resources or deal with accidents. If the settlement inventory of resources is insufficient to meet sustenance requirements, the health of the occupants is reduced. Once the health of an occupant reaches zero they die and are removed from the simulation.
Not surprisingly, the Agreeable personality type was the only agent to survive the entire duration of the simulations. Having the highest coping capacity, Agreeables were the most resilient when exposed to stressful situations and habitat disasters. Neurotics fared the worst and showed the least adaptability under stress. When selecting crews for the first space settlements, phycological profiles will be key to ensuring stable communities on Mars or elsewhere on the frontier.
Conceptual rendering of a Blue Alchemist solar cell fabrication facility on the Moon. Credits: Blue Origin
Jeff Bezos’ new initiative called Blue Alchemist made a splash last month boasting that the team had made photovoltaic cells, cover glass and aluminum wire from lunar regolith simulant. This is an impressive accomplishment if they have defined the end-to-end process which (with refinements for flight readiness) would essentially provide a turnkey system to fabricate solar arrays to generate power on the Moon. The announcement claimed that the approach “…can scale indefinitely, eliminating power as a constraint anywhere on the Moon.” Actually, this may not be possible at first for a single installation as surface based solar arrays can only collect sunlight during the lunar day and would have to charge batteries for use during the 14 day lunar night, unless they were located at the Peaks of Eternal Light near the Moon’s south pole. But if scaling up manufacturing is possible, coupled with production of transmission wire as described, a network of solar power stations in lower latitudes could be connected to distribute power where it is needed during the lunar night.
Very few details were revealed about the design outputs of the end products (not surprisingly) in Blue Origin’s announcement, particularly the “working prototype” solar cell. An image of the component was provided but it was unclear if the process fabricated the cells into a solar array or if the energy conversion efficiency was comparable to current state of the art (around 21%). Nor do we know how massive the manufacturing equipment would be, how much periodic maintenance is needed or if humans are required in the process. Still, if a turnkey manufacturing plant could be placed on the Moon and it’s output was solar arrays sourced from in situ materials, it would significantly reduce the costs of lunar settlements by not having to transport the power generation equipment from Earth. This particular process has the added benefit of producing oxygen as a byproduct, a valuable resource for life support and propulsion.
Research into production of solar cells on the Moon from in situ materials is not new. NASA was looking into it as recently as 2005 and there are studies even dating back to 1989. Blue’s process produces iron, silicon, and aluminum via electrolysis of melted regolith, using an electrical current to separate these useful elements from the oxygen to which they are chemically bound. Solar cells are produced by vapor deposition of the silicon. The older studies referenced above proposed similar processes.
It would be interesting to perform an economic analysis comparing the cost of a solar power system supplied from Earth by a company focusing on reducing launch costs (say, SpaceX) with that of a company like Blue Origin that fabricated the equipment from lunar materials. Peter Hague has done just that in a blog post on Planetocracy using his mass value metric.
Hague runs through the numbers comparing SpaceX’s predicted cost per kilogram delivered to the Moon by Starship with that of Blue Origin’s New Glenn. At current estimates the former is 5 times cheaper than the latter. Thus, to best Starship in mass value, Blue Alchemist would have to produce 5kg of solar panels for every 1kg of equipment delivered to the Moon, after which it would be the economic winner. Siting a recent analysis of lunar in situ resource utilization by Francisco J. Guerrero-Gonzalez and Paul Zabel (Technical University of Munich and German Aerospace Center (DLR), respectively) predicting comparable mass output rates, Hague believes this estimate is reasonable.
Perhaps we should not get ahead of ourselves as Blue Origin’s timeline for development of their New Glenn heavy-lift launch vehicle is moving a glacial pace and one wonders if they have the cart before the horse by siphoning off funds for Blue Alchemist. Jeff Bezos is free to spend his money any way he wishes and definitely seems to be in no hurry.
Conceptual illustration of New Glenn heavy-lift launch vehicle on ascent to orbit. Credits: Blue Origin
But SpaceX’s Starship has not made it to space yet either and after we see the first orbital flight, hopefully as early as next week, the company will have to demonstrate reliable reusability with hundreds of flights to achieve economies of scale commensurate with their predicted launch cost of $2M – $10M. As SpaceX has demonstrated with it’s launch vehicle development process it is not a question of if, it is one of when.
Image of full stack Starship at Starbase in Boco Chica, TX. Credits: SpaceX
As both companies refine their approach to space development, will it be the tortoise or the hare that wins the mass value price race for the cheapest approach to power on the Moon? Or will each company end up complementing each other with energy and transportation infrastructure in cislunar space? Either way, it will be exciting to watch.
Artist’s impression of a lunar landing pad. Credits: SEArch+
When humanity returns to the Moon and begins to build infrastructure for permanent settlements, propulsive landings will present considerable risk because rocket plumes can accelerate lunar dust particles in the bare regolith to high velocities which could result in considerable damage to nearby structures. Obviously, nothing can be done about the first spacecraft that will return to the moon later this decade unless they use their own rocket plume to create a landing pad like the concept proposed in a NIAC Grant by Masten Space Systems (now part of Astrobotic).
Flight Alumina Spray Technique (FAST) instant landing pad deployment during lunar landing. Source: Matthew Kuhns, Masten Space Systems Inc (now Astrobotic)
Therefore, before significant operations can begin on the Moon that require lots of rockets, a high priority will be construction of landing pads to prevent sandblasting by rocket plume ejecta of planned structures such as habitats, science experiments and other equipment. Several methods are currently being studied. Some require high energy consumption. Others could take a long time to implement. Still others are technologically immature. Which technique makes the most economic sense? Phil Metzger and Greg Autry examine options for the best approach to this urgent need in a November 2022 paper in New Space.
A lunar landing pad should have an inner and outer zone. The inner zone will have to withstand the intense heat of a rocket plume during decent and ascent. The outer zone can be less robust as the expanding gases will cool rapidly and decrease in pressure but will still be expanding rapidly, so erosion will have to be mitigated over a wider area.
Landing pad layout showing inner and outer zone measurements proposed in this study (Figure 1 in paper). Credits: Philip Metzger and Greg Autry / New Space – Lunar surface image credit: NASA.
Several processes of fabricating landing pads were examined by the authors. Sintering of regolith is one such technique, where dust grains are heated and fused by a variety of methods including microwave heating or focused solar energy. SSP has reported on the latter previously, but in this study it was noted that that technology needs further development work. Fabricating pavers by baking in ovens in situ was also examined in a addition to infusion of a polymer into the regolith to promote particle adhesion.
An economic model was developed to support construction of landing pads for NASA’s Artemis Program based on experimental data and the physics for predicting critical features of construction methods. Factors such as the equipment energy consumption, the mass of microwave generators compared to the power output needed to sinter the soil to specified thickness, and the mass of polymer needed to infuse the regolith to fabricate the pads were included in the model. Other factors were considered including the costs associated with program delays, hardware development, transportation of equipment to the lunar surface, and reliability.
When varying these parameters and comparing different combinations of manufacturing techniques, the trade study optimized the mass of construction equipment to balance the costs of transportation with program delays. The authors found that from a cost perspective, microwave sintering makes the most sense for both the inner and outer regions of the landing pad, at least initially. When transportation costs come down to below a threshold of $110K/kg then a hybrid combination of microwave sintering in the inner zone and polymer infusion of regolith in the outer zone makes the most sense.
Once astronauts land safely and begin EVAs on the lunar surface, they can keep from tracking dust into their habitat by taking an electron beam shower.
Other lunar dust problems and their risks can be mitigated with solutions covered previously on SSP.
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
Conceptual illustration of an oxygen pipeline located at the lunar south pole. Credits: Peter Curreri
This year’s list of NASA Innovative Advanced Concepts (NIAC) Phase I selections include a few awards that look promising for space development. For wildcatters (or their robotic avatars) drilling for water ice in the permanently shadowed craters at the lunar south pole and cracking it into hydrogen and oxygen, Peter Curreri of Houston, Texas based Lunar Resources, Inc. describes a concept for a pipeline to transport oxygen to where it is needed. Clearly oxygen will be a valuable resource to settlers for breathable air and oxidizer for rocket fuel if it can be sourced on the Moon. The company, whos objective is to develop and commercialize space manufacturing and resources extraction technologies to catalyze the space economy, believes that a lunar oxygen pipeline will “…revolutionize lunar surface operations for the Artemis program and reduce cost and risk!”.
Out at Mars, Congrui Jin from the University of Nebraska, Lincoln wants to augment inflatable habitats with building materials sourced in situ utilizing synthetic biology. Cyanobacteria and fungi will be used as building agents “…to produce abundant biominerals (calcium carbonate) and biopolymers, which will glue Martian regolith into consolidated building blocks. These self-growing building blocks can later be assembled into various structures, such as floors, walls, partitions, and furniture.” Building materials fabricated on site would significantly reduce costs by not having to transport them from Earth.
A couple of innovations are highlighted in this NIAC grant. First, Jin has studied the use of filamentous fungi as a producer of calcium carbonate instead of bacteria, finding that they are superior because they can precipitate large amounts of minerals quickly. Second, the process will be self-growing creating a synthetic lichen system that has the potential to be fully automated.
In addition to building habitats on Mars, Jin envisions duel use of the concept on Earth. In military logistics or post-disaster scenarios where construction is needed in remote, high-risk areas, the “… self-growing technology can be used to bond local waste materials to build shelters.” The process has the added benefit of sequestration of carbon, removing CO2 from the atmosphere helping to mitigate climate change as part of the process of producing biopolymers.
Graphical depiction of biomineralization-enabled self-growing building blocks for habitats on Mars. Credits: Congrui Jin
To reduce transit times to Mars a novel combination of Nuclear Thermal Propulsion (NTP) with Nuclear Electric Propulsion (NEP) is explored by Ryan Gosse of the University of Florida, Gainesville.
Conceptual illustration of a bimodal NTP/NEP rocket with a wave rotor enhancement. Credits: Ryan Gosse
NTP technology is relatively mature as developed under the NERVA program over 50 years ago and covered by SSP previously. NTP, typically used to heat hydrogen fuel as propellant, can deliver higher specific impulse then chemical rockets with attractive thrust levels. NEP can produce even higher specific impulse but has lower thrust. If the two propulsion types could be combined in a bimodal system, high thrust and specific impulse could improve efficiency and transit times. Gosse’s innovation couples the NTP with a wave rotor, a kind of nuclear supercharger that would use the reactor’s heat to compress the reaction mass further, boosting performance. When paired with NEP the efficiency is further enhanced resulting in travel times to Mars on the order of 45 days helping to mitigate the deleterious effects of radiation and microgravity on humans making the trip. This technology could make an attractive follow-on to the NTP rocket partnership just announced between NASA and DARPA.
Finally, an innovative propulsion technology for hurling heavy payloads rapidly to the outer solar system and even into interstellar space is proposed by Artur Davoyan at the University of California, Los Angeles. He will be developing a concept that accelerates a beam of microscopic hypervelocity pellets to 120 kilometers/s with a laser ablation system. The study will investigate a mission architecture that could propel 1 ton payloads to 500 AU in less than 20 years.
Artist depiction of pellet-beam propulsion for fast transit missions to the outer solar system and beyond. Credits: Artur Davoyan
