Ablative Arc Mining for the Moon and Asteroids

Unlocking water and resources on the moon and asteroids will be a huge breakthrough for space development. It will give us water, building materials, and propellants.

Water is the most critical component in the near-term and is therefore the focus of many studies. However, being able to mine other resources with the same system will become critical in the future. A good mining system should therefore encompass extraction and collection of water in parallel with as many other local materials as possible. Ablating surface material using electric arcs creates free ionized particles that can be sorted by mass into material groups and transported to a relevant collector by electromagnetic fields. Collectors specific to each material type are used in parallel to enable maximum collection efficiencies and storage conditions for retention. The ionizing ablation arc, electromagnetic transport and sorting, and collector modules are housed within a mobile surface crawler, potentially leading to diverse, efficient, and wide-coverage in-situ resource utilization for human space exploration. By using an arc to both ablate and ionize the regolith particles, the transport and collection of the volatiles is more controlled and efficient than the random walks of rarefied neutral particionles that are relied upon in thermal mining techniques. This increases the rate particles are collected, and reduces losses from condensation on non-intended surfaces. Using a magnetic field to separate volatiles means this technique can readily apply to any regolith constituent, including water and metal ions, in a single system architecture.

To prove feasibility of ablative lunar arc mining and to determine potential mining production rates and power requirements, further investigations are required. The overall goal of the Phase I NIAC is to propose a feasible ISRU architecture using ablative arc mining to support planned lunar exploration missions.

This will be achieved through three specific objectives:
1) Define a combination ablative arc and electromagnetic transport system for the simultaneous extraction and collection of water, silicon, and nickel;
2) Design a mission architecture capable of producing 10,000 kg/yr of water to support planned lunar exploration programs; and
3) Evaluate the proposed mission architecture concept against others ISRU concepts under investigation, including resistive heating, microwave heating, and direct solar heating.

The two main outcomes of the work will be
1) a mission architecture design at Mission Concept Review level, and

2) a mission level trade study of ISRU concepts using criteria evaluated within the framework of supporting a crewed lunar mission.

Development of ISRU mining architectures are a necessary component for enabling long-term human exploration missions to the Moon or Mars. An ablative arc mining system that extracts and captures multiple volatile constituents in a single system offers significant improvements over other systems that collect only one constituent at a time.

This is a NASA NIAC phase I study.

NASA NIAC Grants

Phase I (FY21)

$125,000 for a nine-month study
12 to 18 awards per year

Phase II (FY21)

$500,000 for a two-year study
Six to eight awards per year

Phase III (FY21)

$2 million for a two-year study
One award per year

8 thoughts on “Ablative Arc Mining for the Moon and Asteroids”

  1. For the Moon we can send astronauts. For asteroids, the distance is too great (both to them and between them) so we need robots. Elon's self-driving computers will come in handy for this. Also the distance is too great for effective remote control, so we'll need at least rudimentary AI to do the mining.

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  2. How do you strike an arc in a vacuum? Are they introducing some ionizable gas to begin with to get things going? At the pressures you'd typically find on the moon or an asteroid, you'd be lucky to get even a glow discharge.

    I'm not sure about the electrical resistivity of lunar regolith, it's possible you could just stick a couple of electrodes into the ground, and resistance heat would drive off enough gas to get it started, then the arc would form between the electrodes.

    My thought was that, given that highly effective reflective optics are easy on the Moon, you could dig a hole, cap it with a cover that had a transparent port, and reflect concentrated sunlight in through the port. Once you started driving off enough gas, you could circulate it through a filter and reintroduce it near the port as shield gas, (Otherwise the port would become contaminated and all the heat would soon stop there.) and the heat would build high enough to render even a lot of normally solid materials volatile. The theoretical limit is, after all, solar surface temperature.

    Sunlight is cheap on the moon, as is vacuum. Electricity? Not so cheap.

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  3. The problem with this concept is contamination. Particles in gases distribute evenly and all surfaces get coated with gunk regardless of the use of magnetic fields. So the result will be that it can only be operated for a certain, lowish, production volume before it either breaks down or needs 'cleaning'. If we select this solution we need space janitors… cool.

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  4. So. I don't want to be that guy, but:
    Development, exploitation, and utilizing available resources on or near the moon surface to foster a lunar colony, seed a cis-lunar presence, and contribute to extra-solar jump-off missions is beyond noble, but large-scale strip mining and crater-size open-pit excavations need to be evaluated, irrespective of how 'nifty-do' the mining tech. Perhaps processing the intended habitation excavations, immediate surrounding, and beneath may be an acceptable first footprint of regolith input.
    Though, I'm all in for < 50m asteroid crushers and pulverisers.

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