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Ethos Space has ambitious plans for the Moon and beyond

Conceptual illustration of a SpaceX Starship on a lunar landing pad made from in situ materials by Ethos Space, which plans to use lunar resources for space development. Credits: Starship image: SpaceX; Lunar landing pad and landscape: Grok 2

Kevin Cannon, one of our favorite researchers on ISRU here on SSP, recently appeared on The Space Show to discuss his new position as Senior Lunar Geologist for Ethos Space, a Los Angeles based lunar infrastructure startup that just emerged from stealth last June. Near term (by 2028), the company plans to support the Artemis program by attempting to robotically building landing pads for Starship using lunar regolith, an application SSP covered last year in a ground breaking trade study. Ethos also hopes to extract oxygen from lunar regolith which makes up 80% of rocket propellant and could be a major market segment in a cislunar economy. Incidentally, a few years ago Cannon looked into where on the Moon is the best place to source oxygen.

Long term (20 – 30 years from now) Ethos hopes to use lunar materials to manufacture a sunshade commissioned by world governments that would be placed at the L1 Sun-Earth Lagrange point to combat global warming by blocking 2% of sunlight that reaches our planet. Ethos Space CEO, Ross Centers, is founder of the nonprofit Planetary Sunshade Foundation which issued a report on the state of space based radiation modification about a year ago.

Conceptual illustration of planetary sunshade fabricated from materials sourced on the Moon. Credits: Ethos Space
Diagram depicting the proposed location for a sunshade located at the L1 Sun-Earth Lagrange point (not to scale). Credits: Planetary Sunshade Foundation
Ray trace showing that the more acute umbra shadow of a sunshade would not reach Earth while the diffuse penumbra is what would cover our planet (not to scale). Credits: Planetary Sunshade Foundation

Cannon believes that a sunshade is a better geoengineering solution to cool the climate then cloud seeding with sulfur dioxide aerosols as at least one startup company, Make Sunsets, is proposing. Cannon believes this approach, which he says amounts to “using pollution to fight pollution”, will not be very popular with the general public. Make Sunsets counters this argument with an analysis available on their website showing that sulfur dioxide released high in the stratosphere is highly effective in counteracting the warming effect of carbon dioxide while dispersing to negligible levels globally reducing the chance of producing acid rain, the primary concern of sulfur releases in the lower atmosphere. In fact, a paper in Geophysical Research Letters published last August documents evidence that recent regulations on cargo ship emissions limiting sulfur pollutants may have actually contributed to global warming. In 2020 the International Maritime Organization (IMO) instituted new regulations reducing the maximum allowed sulfur emission per kg of fuel in ships by 80%. As a result, artificial clouds created by ship emissions decreased causing northern hemisphere surface temperatures to rise. This example reinforces the need to study geoengineering projects carefully to prevent unforeseen consequences. With respect to the sunshade, Cannon anticipates that international coordination will definitely be required as some countries may have farm land that would actually benefit from anticipated warming so may not want these regions shaded.

Back to the Moon: On The Space Show podcast Cannon mentioned that Ethos will be partnering with Astrolab, a Hawthorne, California based company which has already been awarded a NASA contract to develop a Lunar Terrain Vehicle for the Artemis program. Astrolab’s current concept, dubbed FLEX, is designed to carry two suited astronauts, has a robotic arm for science excavations, and can survive the extreme temperatures at the Lunar South Pole. The rover can be teleoperated remotely from Earth or driven by suited astronauts. The Ethos robotic system for fabricating lunar landing pads would be towed behind this rover while melting the regolith in place forming molten stripes over multiple passes that cool into igneous rock that would be very robust. The mechanism for how the regolith will be melted was not disclosed but if they are guided by the trade study mentioned above, microwave sintering makes the most sense.

Image of Astrolab’s FLEX rover which may tow the Ethos Space robotic system for melting lunar regolith to fabricate landing pads on the Moon. Credits: Astolab

In a post a few years ago on his blog Planetary Intelligence, Cannon makes the case that mining Luna for platinum group metals (PGM) would be more economically feasible than from near-Earth objects (NEO) because of transit times and operational difficulties due the typical NEO being an “…irregular shaped rubble pile–or basically a space sandcastle of loose dust and boulders–held weakly together by cohesion and microgravity, and spinning rapidly.” In addition, terrestrial ore grades are higher than in NEOs potentially making the economics challenging to compete with mines on Earth. The CEO of asteroid mining company Astroforge, Matt Gialich, begs to differ. He thinks there is a business case for mining NEOs and has venture capital backers that agree. Cannon actually collaborated with Gialich on a paper making the case for mining PGMs from main belt asteroids which SSP covered last year. However, the distances involved make near term profits difficult, and Astroforge is now focusing on NEO’s relatively close to Earth. Gailich also appeared on The Space Show this year and addressed the terrestrial ore grade question when I posed it to him, essentially saying that extraction of PGMs from NEOs could be economically competitive with terrestrial mines because they are so deep and have slim profit margins.

Both Ethos and Astroforge will have mission results in the next decade, although they are targeting completely different markets. Hopefully, both will succeed.

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The prospects for mining precious metals and structural materials from asteroids

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

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

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

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

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

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

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

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

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

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