Planetoid Mines Corporation’s ISRU off-world extractor. Credits: Planetoid Mines Corporation
A New Mexico based startup called Planetoid Mines Corporation has just completed development of an autonomous robotic platform for mining the moon or other extraterrestrial worlds via in situ resource utilization. The system features a multi-head icy regolith extractor that feeds directly into an ore beneficiation tool, the output of which is channeled to an onboard oven that extrudes 3D printed structures via a robotic arm.
Through a post on his LinkedIn profile, CEO Kevin DuPriest says “Our self-contained system provides end-to-end continuous mining operations with multiple excavator heads, mineral concentration through beneficiation, a pyrometallurgy oven and thermal printing head. Using lunar surface minerals the system can print landing pads, extrude fused quartz rods, large antenna arrays, etc. ISRU platform designed to fit most lunar landers.”
The company’s website highlights a solid oxide hydrogen fuel cell and steam electrolysis stack that can split lunar water into hydrogen and oxygen for rocket fuel while generating heat and power on-demand. There is even potential dual use benefits of the ISRU architecture for mining on Earth. The website intimates the possibility of a mission to the Moon by 2022, but provides no further details on suppliers of launch or lander services.
In a recent Tweet DuPriest announced the company is considering going public through a Special Purpose Acquisition Corporation (SPAC) and looking for partners to assist with cislunar infrastructure and logistics for mission operations.
A new YouTube channel has just been launched called Space Matters. Hosted by Rhonda Stevenson, President/CEO of the Tau Zero Foundation, the show is a weekly digest covering a wide array of current space activities, challenges and accomplishments which aims to show how our success in space will improve life on Earth. This could become an influential forum for discussion among industry leaders on how to steer humanities course toward becoming a spacefaring civilization. The first episode, a panel discussion with pillars of the space industry, aired on March 20th and featured Jeff Greason of Tau Zero and Electric Sky, Justin Kugler of Redwire Space, Grant Anderson of Paragon Space Development Corporation, Andy Aldrin of the ISU Center for Space Entrepreneurship, at FIT and Rod Pyle, editor of Ad Astra and author of Space 2.0. The group had a lively discussion on each of their contributions to space development as well as current trends in the New Space economy. Subscribe to get an update every week on why Space Matters.
Peaks of Eternal Light at the lunar south pole annotated with crater labels. Mosaic of 40 images taken by the ESA SMART-1 spacecraft 2005/2006. Area covers 500 x 150 km. Credits: ESA/SMART-1/AMIE camera team; M. Ellouzi/B. Foing, CC BY-SA 3.0 IGO
As most space settlement enthusiasts know, the Peaks of Eternal Light on the rims of craters in the lunar polar regions hold much promise as the ideal location to place collectors for solar energy to power ice mining operations. At the south pole in particular, these peaks lie within just a few kilometers of large frozen water deposits in the permanently dark shallows. But how much solar power is available? Companies such as Trans Astronautica Corporation will want to know so they can inform plans for their Sun Flower™ collector invention as part of a Lunar Polar Mining Outpost.
In a paper posted this month on the pre-print server arXiv.org, a team of researchers at Harvard University and Technische Universität Berlin present the results of a study to answer this question. Using data from high resolution maps of solar illumination on the ridges of Shackleton crater and others, they determined the total available power from collector towers of various heights if they were placed at these locations.
The study found that the power available depends heavily on the height of the panels above the local surface but could be substantial, from a few megawatts for towers of heights less than 100m up to the gigawatt range for towers of 500m or more. This is sufficient power for mining several thousand tons of water per year from Shackleton crater.
Image of Biosphere 2, a research facility to support the development of computer models that simulate the biological, physical and chemical processes to predict ecosystem response to environmental change. Credits: Biosphere 2 / University of Arizona
Once cheap access to space is realized, probably the most important technological challenge for permanent space settlements behind radiation protection and artificial gravity is a robust environmental control and life support system (ECLSS). Such a system needs to be reliably stable over long duration space missions, and eventually will need to demonstrate closure for permanent outposts on the Moon, Mars or in free space. In his thesis for a Master of Science Degree in Space Studies, Curt Holmer defines the stability of the complex web of interactions between biological, physical and chemical processes in an ECLSS and examines the early warning signs of critical transitions between systems so that appropriate mitigations can be taken before catastrophic failure occurs.
Holmer mathematically modeled the stability of an ECLSS as it is linked to the degree of closure and the complexity of the ecosystem and then validated it against actual results as demonstrated by NASA’s Lunar-Mars Life Support Test Project (LMLSTP), the first autonomous ECLSS chamber study designed by NASA to evaluate regenerative life support systems with human crews. The research concluded that current computer simulations are now capable of modeling real world experiments while duplicating actual results, but refinement of the models is key for continuous iteration and innovation of designs of ECLSS toward safe and permanent space habitats.
This research will be critical for establishing space settlements especially with respect to how much consumables are needed as “buffers” in a closed, or semi-closed life support system, when the model’s metrics indicate they are needed to mitigate instabilities. Such instabilities were encountered during the first test runs of Biosphere 2 in the early 1990s.
As SpaceX races to build a colony on Mars, they will need this type of tool to help plan the life support system. Holmer believes that completely closed life support systems for relatively large long term settlements are at least 15 to 20 years away. That means that SpaceX will need to resupply materials and consumables due to losses in their initial outpost who’s life support system in all probability will not be completely closed during the early phases of the project over the next decade. Even SpaceX cannot reduce launch costs low enough to make long term resupply economically viable. They will eventually want to drive toward a fully self sustaining ECLSS. That said, depending on how the company funds its initiatives and sets up it’s supply chains, they may not need a completely closed system for quite some time.
Of course there are sources of many of the consumables on Mars that could support a colony but not all the elements critical for ecosystems, such as nitrogen, are abundant there. There are sources of some consumables outside the Earth’s gravity well which could lower transportation costs and extend the timeline needed for complete closure. SSP covered the SHEPHERD asteroid retrieval concept in which icy planetesimals, some containing nitrogen and other volatiles needed for life support, could be harvested from the asteroid belt and transported to Mars as a supply of consumables for surface operations. TransAstra Corporation is already working on their Asteroid Provided In-situ Supplies family of flight systems that could help build the infrastructure needed for this element of the ecosystem. It may be a race between development of the competing technologies of a self-sustaining ECLSS vs. practical asteroid mining. The bigger question is if humans can thrive long term on the surface of Mars under .38G gravity. In the next century, O’Neill type colonies, perhaps near a rich source of nitrogen such as Ceres, may be the answer to where safe, long term space settlements with robust ECLSS habitats under 1G will be located.
Curt Holmer appeared recently on the The Space Show discussing his research. I called the show and asked if he had used his modeling to analyze the stability of ecosystems sized for an O’Neill-type colony. He said he had only studied habitats up to the size of the International Space Station, but that it was theoretically possible to analyze this larger ecosystem. He said he would like to pursue further studies of this nature in the future.
Artist’s concept of projects which could benefit from DARPA’s (NOM4D) plan for robust manufacturing in space. Credits: DARPA
Pronounced “NOMAD” the Defense Advanced Research Projects Agency plan aims to develop technologies for adaptive, off-earth manufacturing to fabricate large structures in space and on the Moon.
Bill Carter, program manager in DARPA’s Defense Sciences Office explains in an announcement of the program, “We will explore the unique advantages afforded by on-orbit manufacturing using advanced materials ferried from Earth. As an example, once we eliminate the need to survive launch, large structures such as antennas and solar panels can be substantially more weight efficient, and potentially much more precise. We will also explore the unique features of in-situ resources obtained from the moon’s surface as they apply to future defense missions. Manufacturing off-earth maximizes mass efficiency and at the same time could serve to enhance stability, agility, and adaptability for a variety of space systems.”
The program will be split into three 18 month phases driven by metrics associated with progressively challenging exemplars such as respectively, a 1-megawatt solar array, a 100m diameter RF reflector, and finally IR reflective structures suitable for use in a segmented long-wave infrared telescope.
Lessons learned from the program could be applied to on-orbit manufacturing operations by commercial space companies as launch costs come down and access to cislunar space becomes more routine for both government and commercial entities.
Artist impression of ISRU activities on the Moon. Credits: NASA
What do space experts in industry and academia think will be the technical and policy challenges to overcome for a sustainable lunar outpost leveraging ISRU by 2040 to be realized? A survey using the Delphi method has just been completed to answer this question. The results were just released as a pre-proof in Acta Astronautica. Significant contributors in the fields of ISRU technologies, space architecture, power systems, and space exploration participated in the survey.
There was a group consensus that NASA’s Artemis mission returning humans to the Moon would be delayed by at least 2 years from the previous administration’s target of 2024 due to uncertainty in U.S. policy over the next few years. No surprise here. There was also agreement that ISRU processes could add significant power requirements on the order of 1 MW to a lunar base, and that photovoltaic systems were preferred over nuclear power sources because of a “…political distaste for space nuclear power systems”. Of particular note, the survey participants could not reach agreement on the impact that Covid-19 would have on space exploration.
Artist impression of activities at a Moon Base which could include oxygen production. Credits: ESA – P. Carril
Kevin Cannon of the Cannon Group at the Colorado School of Mines can help find the answer. In a recent post on his Planetary Intelligence blog, the Assistant Professor of Geology and Geological Engineering describes a trade study comparing extraction of oxygen from regolith such as Metalysis’ ESA funded study to getting O2 from ice mining at the lunar poles as favored by NASA. Nothing stands out from a cursory look at the pros and cons of each approach.
In a more data driven analysis to compare apples to apples, Cannon examines energy costs of mining oxygen and plots it against the amount of bulk material that has to be processed to produce an equal amount of O2 from different sources ranging from plain silicate regolith to various grades of water ice endmembers. The analysis even includes processing material from various types of asteroid resources. The types of ice/regolith mixtures can vary widely as described in one of Cannon’s tweets.
Artist’s impression of different types of water ice / regolith endmembers. Credits: Lena Jakaite / strike-dip.com / Colorado School of Mines
Cannon’s analysis reaches the conclusion that “At 1.5-2% water by weight, icy regolith is essentially on par with O2-from-regolith on a joule for joule basis. In other words, if you had a pile of icy regolith already sitting on the surface, it makes sense to throw it out if the grade is less than about 1.5% and extract oxygen directly from the silicate regolith instead.”
ArmorHab transport habitat configured for artificial gravity. Credits: Dark Sea Industries LLC / University of New Mexico / The Mars Society
The innovative ArmorHab mission architecture was presented at the Mars Society Conference in 2016. This novel approach should be considered as part of a strategy for settlement of the Red Planet. The concept integrates several engineering solutions for habitat design to address radiation protection, life support, and transportation while leveraging in situ resource utilization to enhance crew health, safety and reduce costs.
The basic building block of the architecture is a cylindrical Mylar shell wrapped in superconductive tape providing radiation protection through emulation of a magnetosphere. This structure is encased in a protective aerogel for strength and insulation including layers of water ice to further protect the crew from micrometeorites and algae bioreactors for scrubbing carbon dioxide for life support.
ArmorHab wall structure with superconducting tape for radiation protection and algae bioreactors for life support. Credits: Dark Sea Industries LLC / University of New Mexico / The Mars Society
Leveraging Buzz Aldrin’s Mars Cycler invention, the plan starts by building out infrastructure in cislunar space including automated factories on the Moon, then expanding out to Mars with space stations, cycling habitats and connecting “trucks” to provide transport to and from the surface of each destination.
Illustration of cycler model showing six TransportHabs, three space stations and a Mars Truck. Credits: Dark Sea Industries LLC / University of New Mexico / The Mars Society
Left – Image of the Photovoltaic Radio-frequency Antenna Module (PRAM). Credits: of U.S. Naval Research Laboratory. Right: X-37B orbital test vehicle. Credits: Boeing
The first on-orbit demonstration of wireless power transmission, technology that could eventually support elements of a space solar power satellite has just been completed and published in the IEEE Journal of Microwaves. This experiment, the first flight test of a solar-to-RF Photovoltaic Radio-frequency Antenna Module (PRAM) lovingly referred to as a “sandwich module”, was performed on the U.S Airforce’s X-37 Orbital Test Vehicle, the launch of which SSP covered last May. Preliminary results have duplicated in space the expected power transmission that was tested on the ground pre-flight. Although testing is just getting started, the results show proof of concept of this prototype PRAM paving the way for the next phase of the Space Solar Power Incremental Demonstrations and Research (SSPIDR) project planned by Air Force Research Laboratory. The primary objective of SSPIDR is delivery of power to forward deployed expeditionary forces on Earth which would assure energy supply with reduced risk and lower logistical costs. The technology could eventually be used for commercial energy production.
Modular solar-to-RF panels based on the PRAM concept will enable very large radio frequency power beaming apertures to be assembled from a single panel design leading to scalability, lower mass and reduced costs.
Depiction of the PRAM functional mechanism for solar power satellites. Credits: Christopher T. Rodenbeck et al. / IEEE Journal of Microwaves
The next step in Phase 1 of the the SSPIDR project will be the world’s first space-to-ground power beaming demonstration of a solar to-RF modular panel currently planned for 2023.
Credits: Advanced Science Open Access / Wiley‐VCH GmbH
In space, conventional aluminum alloys tend to degrade when exposed to stellar-radiation such as solar flares or coronal mass ejections resulting in softening of the material to the point of dissolving over time. This property has ruled out aluminum as a lower mass material suitable for space structures…until now.
A new blend of aluminum has been discovered that may provide light weight radiation hardened material for protective hulls of spacecraft. The new research by Matheus A. Tunes et al.* was published in Advance Science. Using a metallurgical strategy called “crossover alloying,” the researchers combined 5xxx (AlMg) with the 7xxx (AlZn) alloy series obtaining beneficial properties of both such as high formability and high strength. The new amalgam was then age hardened to form a complex crystal structure of Mg32(Zn,Al)49 called a “T-Phase” that when subjected to heavy ion bombardment representative of stellar radiation, achieved a high degree of radiation tolerance. The results of the research show that the alloy is a promising candidate for applications in space.
* Authors of the Advance Science paper: Matheus A. Tunes, Lukas Stemper, Graeme Greaves, Peter J. Uggowitzer, Stefan Pogatscher.
