Artist’s illustration of a self replicating factory near an asteroid and serviced by a SpaceX Starship. Credits: Michel Lamontagne / Principium
The technology of self replicating machines has been gradually progressing toward maturity over the last few decades. The Space Studies Institute recognized this key enabler of space settlement as far back as the 1980s and covered the topic frequently in its newsletter updates. Now Michel Lamontagne has provided a status update in the latest issue of Principium. On page 50, he highlights the history of self replicating factories, provides a vision for the evolution of the concept for production of space settlement infrastructure and gives a summary of recent developments in key areas of research such as additive manufacturing, machine learning and cheap access to space that will be enablers of this space based industry.
The first factory will be built on the Moon after deep learning simulations prove the concept on Earth. Eventually the more autonomous versions would migrate to Mars and then to what may be the best suited location, the asteroid belt which “…may be the ultimate resource for space settlement construction.” Lamontagne believes “These factories would then follow humanity to the Stars, after having helped to build the infrastructure required for the occupation of the solar system and for Interstellar travel.”
Artist’s rendering of an early self replicating factory on the Moon with SpaceX Starships serving as basic construction elements. Credits: Michel Lamontagne / Principium
If humanity is to ever move off Earth, clearly we will need to be able to have children wherever we establish long term settlements. But, as humans have evolved over millions of years in Earth’s gravitational field, normal gestation may not be possible on the Moon or Mars. This is probably the most important physiological question to be answered before outposts are permanently occupied on these worlds. We can shield people from radiation, we can recycle wastes and use ISRU to replenish consumables for life support. But we may find that artificial gravity either in free space rotating habitats or on planetary surface settlements is required for settlers to have healthy children. In fact, when I asked Dr. Shawna Pandya, a physician and expert in space medicine about it on The Space Show, she said “…that is the million dollar question”.
Numerous studies have shown the deleterious effects of long term microgravity on human health. So we know that humans will need some level of gravity for sustainable occupation. But what level is enough to stave off the effects of lower gravity on human health and what about reproduction under these conditions? Plus, there is the problem of how to run ethical clinical studies to answer these questions? The Japan Aerospace Exploration Agency (JAXA) has started research in this area by studying mice under variable gravity conditions aboard their Kibo module on the International Space Station using a Multiple Artificial-gravity Research System (MARS). Results of this first ever long term space based mouse habitation study with artificial gravity were published in a paper called Development of new experimental platform ‘MARS’—Multiple Artificial-gravity Research System—to elucidate the impacts of micro/partial gravity on mice in Nature back in 2017. The authors* of the paper found that significant decreases in bone density and muscle mass of the mice reared under microgravity conditions were evident when compared to a cohort raised under 1G indicating that artificial gravity simulating the surface of the Earth may prevent negative health effects of microgravity in space. The next obvious step was to test the mice in 1/6 G simulating conditions on the Moon. This experiment was ran in 2019 but the results have not yet been published. SSP has reached out to JAXA with an inquiry on when we can expect a report. This post will be amended with an update if and when an answer is received.
Reproduction of mice or other mammals has not been studied in space under variable gravity conditions. The problem screams out for a dedicated space based artificial gravity facility such as the Space Studies Institute’s G-Lab and others (e.g. Joe Carroll’s Partial Gravity Test Facility ). Even if such a laboratory existed, how would ethical clinical studies on higher mammal animal models to simulate human physiology during pregnancy be carried out? Answering this question will come first before the million dollar one.
June 2, 2023 Update: JAXA finally released the results of their 2019 study on mice subjected to 1/6 G partial gravity in a paper in Nature in April. There is good news and not-so-good news. The good news is that 1/6 G 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.
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* Authors of Development of new experimental platform ‘MARS’—Multiple Artificial-gravity Research System—to elucidate the impacts of micro/partial gravity on mice: Dai Shiba, Hiroyasu Mizuno, Akane Yumoto, Michihiko Shimomura, Hiroe Kobayashi, Hironobu Morita1, Miki Shimbo, Michito Hamada, Takashi Kudo, Masahiro Shinohara, Hiroshi Asahara, Masaki Shirakawa and Satoru Takahash
Diagram depicting the mission architecture of a Mars habitat built from mycelia growth. Credits: 2018 Stanford-Brown-RISD iGEM Team / NASA
Lynn Rothschild, a scientist at NASA’s Ames Research Center in California, has just been awarded a NASA Innovative Advanced Concept (NIAC) Phase 2 grant to continue her synthetic biology studies using mycelium, the branching, thread-like structures of fungi, to “grow” space structures such as habitats, furniture and more. Rothchild previously advised a team working on mycelium production, or what she calls Myco-architecture, for habitats on the Moon and Mars. The project took place at NASA Ames as part of the iGEM Competition in the summer of 2018, and was funded by a NIAC Phase 1 award. Called Stanford-Brown-RISD or Myco for Mars as the they called themselves, the team was composed of students from Stanford University and the duel degree program of Brown University and the Rhode Island School of Design.
This new phase of the research will continue development of mycelia production, fabrication, and testing techniques. Rothschild describes the process on the NASA Myco-architecture Project site: “On Earth, a flexible plastic shell produced to the final habitat dimensions would be seeded with mycelia and dried feedstock and the outside sterilized. At destination, the shell could be configured to its final inner dimensions with struts. The mycelial and feedstock material would be moistened with Martian or terrestrial water depending on mass trade-offs, and heated, initiating fungal (and living feedstock) growth. Mycelial growth will cease when feedstock is consumed, heat withdrawn or the mycelia heat-killed. If additions or repairs to the structures are needed, water, heat and feedstock can be added to reactivate growth of the dormant fungi.”
Artist rendering of a habitat grown on Mars from mycelia. Credits: Emilia Mann / 2018 Stanford-Brown-RISD iGEM Team / NASA
Artist concept of a free space settlement. Credits: Don Davis / NASA
Al Globus has just published a set of cogent responses to objections made by those who question why space settlement should be considered as a goal for humanity. A link to the piece is on his website Free Space Settlement. His analysis first defines what space settlement is, then why it should be pursued and finally refutes point by point, arguments against the endeavor.
Globus positions the case for space settlement around surviving and thriving. Surviving centers on dispersing humanity’s eggs outside of Earth’s basket as a hedge against the risk of catastrophic threats such as “…climate change, major asteroid hits, supervolcano eruptions, nuclear war, pandemic, nearby supernova, and technology run amok.” Even if humanity does survive these potential hazards, in about 5 billion years our sun will transition to a red giant making life on Earth uninhabitable. Clearly our future on the home planet is not assured forever. At current population growth rates, we will have exhausted Earths resources long before then.
Thriving recognizes that expanding into space is the next step in human evolution. Globus reminds us that “…living things want to grow and expand, to thrive, not simply exist.” By settling space “…resource wars are unlikely and unnecessary because our Sun provides billions of times the energy used on Earth and the asteroids provide enough material to make new orbital land hundreds of times greater than the surface area of the Earth.”
To the objection that space is too expensive and that funds would be better spent on Earth, there are two talking points. First, it is always prudent to allocate a small percentage of outlays on planning for the future. NASA’s funding in 2020 was less then 1/2 of a percent (0.48%) of total US expenditures. The US spends quite a bit more on social programs so this argument is very weak. Second, the benefits we receive from space activities in our economy pay significant dividends. SSP has covered the return on space investments and the value of space infrastructure previously.
The next general category of objections falls under “It Can’t Be Done” such as farming in space is not feasible, radiation levels are too high and weightless conditions are intolerable for humans. Globus easily addresses each concern with technological solutions well represented on SSP’s ancillary pages.
An interesting set of protestations are described as “Power Plays” raising the specter of space wars, settlements attacking Earth or cult factions taking over space settlements. And there is the ominous possibility of “Deudney threats” as described in Daniel Deudney’s negative prediction of our space future in his book Dark Skies: Space Expansionism, Planetary Geopolitics, and the Ends of Humanity”. Globus handled these objections quite well and links to his critique of the book in the The Space Review.
Other miscellaneous complaints by doubters are addressed easily by Globus. His talking points are valuable tools to be used in persuasive dialogs with those who may be uninformed on the promise of space development. They should help in building consensus toward moving peacefully out into the solar system and establishing prosperous settlements throughout the galaxy.
Orbiting Modular Artificial-Gravity Spacecraft (OMAGS) concept for testing ecosystems in space – Exterior and cutaway views. Credits: Gregory Dorais / NASA
One of the most important technologies to realize permanent space settlements is the development of self-sustaining controlled ecological life support systems (CELSS). This will require replication of independent self-contained subsets of Earth’s biosphere containing select flora and fauna under controlled conditions for eventual human life support. But are 100% closed ecosystems (with the exception of the exchange of radiation and information) beyond Earth possible? Could a series of controlled evolutionary experiments using machine learning be carried out on controlled ecosystems in space under variable gravity conditions to rapidly optimize the key variables needed to identify the smallest possible CELSS for long term human survival? Gregory Dorais, a research scientist at NASA Ames Research Center, thinks so and describes the strategy in a paper called An Evolutionary Computation System Design Concept for Developing Controlled Closed Ecosystems.
Dorais introduces his concept with a brief description of Closed EcoSystems (CESs) and early efforts by NASA to develop a CELSS for space settlement. Of particular concern are the challenges of putting humans in the equation. There are consequences related to the ratio between human biomass and non-human biomass in ecosystems. On Earth this ratio is low so the ecosystem can self-regulate compensating for imbalances. But in a space biosphere, this ratio in the life support system is comparatively huge leading to significant challenges in maintaining equilibrium. For example, the ISS needs frequent resupply of consumables by spacecraft to replenish losses in the life support system. Wastes that cannot be recycled are either incinerated in the Earth’s atmosphere or exhausted into space. A completely closed system that is self-sustaining has not yet been developed.
Dorais’ design concept for an experimental testbed can be used to explore the viability of different biomass ratios of various combinations of larger animal species and eventually humans. The system consists of a collection of independent CESs controlled and interconnected to generate data for machine learning toward optimizing long term viability. Gradually, the size of the animals in the CES can be increased evolving over time with the ultimate goal of human life support. To kick things off, an Orbiting Modular Artificial-Gravity Spacecraft (OMAGS) is proposed, with room for 24 CESs housed in a 150cm radius centrifuge with appropriate radiation shielding capable of testing the ecosystems under different fractional gravity conditions. The spacecraft is envisioned to be placed in an elliptical orbit in cis-lunar space.
To scale illustration of the OMAGS proposed mission orbit in cislunar space. Credits: Gregory Dorais / NASA
The OMAGS spacecraft has been sized to fit in a SpaceX Falcon Heavy payload fairing.
Illustration of a OMAGS payload sized for a SpaceX Falcon Heavy launch vehicle. Credits: Gregory Dorais / NASA
A NASA patent and tech transfer fact sheet entitled Closed Ecological System Network Data Collection, Analysis, Control, and Optimization System has been issued for this innovation under the NASA Technology Transfer Program.
In a related presentation delivered in November 2018, Dorais says “Once CESs are demonstrated to reliably persist in space, within specified gravity and radiation limits, it is a small step for similar CESs to persist just about anywhere in space (Earth orbit, Moon, Mars, Earth-Mars cycler orbit, asteroids, …) enabling life to permanently extend beyond Earth and grow exponentially.”
