Diagram depicting NASA’s Lunar Water ISRU Measurement Study (LWIMS). Credits: NASA
NASA just published a Technical Memorandum on its Lunar Water ISRU Measurement Study (LWIMS). The TM describes the establishment of a measurement plan for identification and characterization of a water reserve on the Moon. This program would support the Artemis program to achieve a sustainable lunar presence by 2028.
Three primary data inputs feed information into the system. First, predictive modeling provides a ‘water favorability’ index to map out locations on the Moon with water ice potential. This algorithm is fed data by orbital measurements providing information on a regional scale. It is critical that this orbital data is interpreted properly for water-favorable sites on the Moon. To ensure accuracy, lunar landers will take surface measurements in a series of three phases: mobile reconnaissance for validation of the predictive model, focused exploratory missions to verify water’s presence and final reserve mapping to inform an ISRU ice mining plant by 2028.
Artist’s rendition of Airbus lunar lander with ROXY on board. Credits: Airbus
In a breakthrough experiment last month, a team led by Airbus Defence and Space (Friedrichshafen, Germany) has for the first time produced oxygen and other metals from simulated lunar soil with a proprietary process called Regolith to OXYgen and Metals Conversion, or ROXY. The revolutionary new process could be the core of an ISRU value chain on the moon, providing oxygen for habitats or rocket fuel, with added byproducts of metals and alloys as feedstock for additive manufacturing of building materials. This would significantly reduce the cost of settlements on the Moon as the construction materials could be fabricated in situ, without the need to be brought from Earth. Check out Airbus’ animation of ROXY here.
Airbus thinks that the ROXY reactor could have beneficial environmentally friendly applications on Earth as well:
“On Earth, ROXY opens a new pathway to drastically reduce the emissions of greenhouse gases that result from production of metals.” Since the process is essentially free of emissions “…these environmental impacts could be reduced, providing a significant contribution to the UN sustainability goals – another example of how space technologies can improve life on Earth”
In the July Issue of Planetary and Space Science there is a summary of research on beneficiation, the process used for separation of minerals from waste in lunar regolith to prepare feedstock for chemical reactions to produce oxygen. One of the most commonly studied processes is hydrogen reduction of ilmenite (FeTiO3), a mineral abundant in the lunar maria. This type of research is critical to prepare for situ resource utilization (ISRU) needed for lunar settlements.
Benefication processes use differences in physical properties (e.g., density, electromagnetic characteristics) to manipulate materials, most commonly (especially on Earth) with water to facilitate separation. This is not practical in space environments where large scale water use will be more challenging then on Earth. On the Moon, dry techniques such as magnetic or electrostatic process are better suited to this application. The authors describe the physics behind the beneficiation process for ISRU in the lunar environment and survey the research performed thus far on these methods with interesting recommendations for further studies.
Stepwise illustration of the casting process to produce the Lava Hive; (1) deposition of foundation base, (2) regolith is gathered and sintered into a flow channel, (3) molten basalt from the sand/regolith is poured into the channel and allowed to solidify, (4) the next layer of regolith is spread across, and another channel sintered, (5) layer by layer the structure is constructed, (6) loose, un-sintered regolith is excavated from the structure, revealing the completed dome. Credits Aidan Cowley, et al.*
In a paper posted on Academia.edu, the 3rd prize winner for the 2015 NASA 3D Printed Mars Habitat Centennial Challenge called Lava Hive is described by a team* of European researchers. The habitat is produced by additive manufacturing via a ‘lava-casting’ construction technique and utilizing recycled spacecraft structures. Innovations include ‘re-use’ of discarded landing vehicles as part of the central habitat, 3D printed adjacent structures connected to the central habitat and use of a novel ‘LavaCast’ process to fabricate solid structures resistant to radiation and thermal cycling.
Illustration of the Lava Hive. The central habitat core is shown with the smaller 3D printed satellite structures clustered around it. Credits: René Waclavicek, LIQUIFER Systems Group, 2015
The Lava Hive Mars settlement has a number of advantages including a modular design with the ability to expand or adapt to changing mission requirements while “living off the land” with a simple ISRU process utilizing Martian soil, thereby reducing the amount of mass that would need to be launched from Earth.
* Authors of this paper are: Aidan Cowley, Barbara Imhof, Leo Teeney, René Waclavicek, Francesco Spina, Alberto Canals, Juergen Schleppi, Pablo Lopez Soriano
Image credit: Richard Bizley, bizelyart.com / National Space Society
In a paper published in New Space last March, Peter Hague describes a figure of merit he developed to drive policy decisions to help accelerate space exploration and space settlement. The aim of the paper was to generate a single metric for every potential space mission on a common scale for comparison purposes. This ‘mass value’ is the amount of mass that would need to be placed in low Earth orbit (LEO) to perform the same mission using a baseline method. That method would use only storable propellants and Hohmann transfer orbits – no gravity assists, aerocapture, high energy propellants or ISRU.
This approach puts a price on all the add-ons which expand the mission beyond the baseline. One can then use a single normalized scale to calculate how much mass to LEO you would save by making propellant on Mars for example, or by taking advantage of a certain launch window to get a gravity assist.
A hands-off government entity could subsidize space expenditures at a flat rate per kg of mass value, confident they are promoting space development without having legislators involved in engineering decisions.
Aggregating all the missions by a nation, company, or other entity could be used to calculate an analogue of GDP for a space civilization. While this does not measure everything we care about – scientific merit, human occupation, etc – neither does GDP. It does capture the overall capability to move around the solar system; and as such, is as useful for charting our journey to becoming a Type II civilization on the Kardashev Scale as it is for analyzing individual missions.
Thanks to Peter Hague for the material in this post. We’ve heard a rumor that there may be a book forthcoming on the subject. Looking forward to it!
Illustration of an ice extraction concept for collection of water on the Moon. Credits: George Sowers / Colorado School of Mines
Mining the Moon changes everything. In an article in Air and Space, several prominent scientists we’ve been following discuss how in situ resource utilization (ISRU) can close the business case for companies that will build the infrastructure for a cislunar economy.
George Sowers of Colorado School of Mines and lead researcher on a recent study of ice mining in the solar system believes that water is “the oil of space” which can be used for all sorts of propulsion needs as well as supporting life. He believes that “…the economy of space will run off of water.”
Kevin Cannon, who has developed a treasure map for where the ice deposits are located at lunar poles based on satellite data to support ISRU, believes that we need to follow up with actual prospecting hardware to confirm how much water is actually present.
Joel Sercel, CEO of Trans Astronautica Corporation and recent recipient of a Phase II NIAC grant for a Lunar Polar Mining Outpost, has proposed calling a base located at the Moon’s north pole “New Mesopotamia” likening it to the Fertile Crescent in the Middle East on Earth.
Most of the experts agree that fuel depots on the moon are needed for a sustainable economy in cislunar space before we can push off to Mars and beyond.
Ceramics sintered using a MGS slurry system employing classic pottery (potter’s wheel), slip casting, material extrusion (robocasting/direct ink writing), 3D printing (layerwise slurry deposition with binder jetting) and as a reference dry pressing. Credits: David Karl et al.*
Development of the methods for in situ resource utilization on Mars requires validation ahead of time. Making durable and useful ceramics is one such material processing technique that would be valuable. In a paper just posted on the arXiv preprint server to be published in the journal Open Ceramics, David Karl at the Technische Universitaet Berlin and others* present findings on a study of such methods using Mars global simulants (MGS) as a proxy for clay on the Red Planet. These simulants, provided by Kevin Cannon’s Center for Asteroid and Lunar Surface Science (CLASS) Exolith Lab at the University of Central Florida, deliver superior strength when compared to other ISRU materials, as mentioned in a recent Tweet by Cannon.
The paper also documents the results of a sophisticated additive manufacturing technique called layerwise slurry deposition (LSD) using the MGS. As mentioned in the paper’s Introduction, “To highlight the importance of clay as a medium for human civilizations and thought (along with illustrating the usefulness of the unfired/fired concept, as cuneiform tablets are found in unfired as well as fired state), cuneiform tablets from 3D scans were reproduced as inspirational artifacts, illustrating the excellent LSD printing resolution”.
(Top left) Flowchart of MGS slurry production (described in detail in [5]), (top right) schematic of 2 the layerwise slurry deposition and (bottom) processing path for cuneiform tablets from 3D scans of 3 original cuneiform tablets made during the Ur III period (ca. 2100-2000 BC), produced as technological 4 demonstrators for LSD and inspirational artifacts for Mars colonization. Credits: David Karl et al.*
___________
* D. Karl, F. Kamutzki, P. Lima, A. Gili, T. Duminy, A. Zocca, J. Günster,A. Gurlo, Sintering of ceramics for clay in situ resource utilization on Mars, Open Ceramics, https://doi.org/10.1016/j.oceram.2020.100008.
A nuclear thermal rocket concept. Credits: NASA/Wired
In a paper presented at the 8th Symposium on Space Resource Utilization (2016), Bryan Palaszewski analyzes multiple mission architectures for human voyages to the inner and outer solar system. The planet Mercury has permanently shadowed craters at its poles which likely contain frozen water enabling ice mining for rocket propellant and oxygen for breathable air to sustain settlements. The outer planets and their moons are reservoirs of significant amounts of useful gases such as hydrogen, helium 3, methane, ethane, and ammonia which can be utilized as in-situ resources. Through nuclear propulsion and living off the land with ISRU, travel times can be reduced and payloads increased for both robotic and human missions. With a positive vision for eventual space settlement, Palaszewski concludes the paper with “These technological innovations will enable Krafft Ehricke’s vision of a polyglobal civilization“.
Paragon Space Development Corporation, a subcontractor for Dynetics which is one of the three companies NASA has selected to begin work on designs for human lunar landers, was just awarded a Small Business Innovation Research (SBIR) Phase I grant to develop its ISRU Collector of Ice in a Cold Lunar Environment or ICICLE. The system will use a cold trap for collecting and purifying water from ice mining the permanently shadowed regions of the lunar poles. The purification and collection of lunar water is a critical step in generating in-situ propellant, breathable oxygen, and potable water for space settlements and the cislunar economy.
Artist concept of dining in space. Credits: Disney/Eater
In a recent Twitter thread Kevin Cannon shares his thoughts on the logistics of feeding an expanding population as humans settle other worlds. His “food quality” model compares different food preparation venues in an effort to highlight the challenges of feeding folks in in remote locations such as space settlements (and no, there likely won’t be food trucks in space).
Rough index of “food quality”. Credits: Kevin Cannon / Twitter
The obvious goal is sustainable, high frequency food replenishment utilizing in situ resource utilization (ISRU). Cannon recently published a paper in which he modeled the calorie needs and land requirements for a martian settlement that reaches a population of one million people becoming self-sufficient within a hundred years. A wealth of research relevant to space settlement can be found at his website kevin.cannon.rocks.
