Critical challenges and technology development for colonizing and developing the moon are being performed. This includes getting oxygen, water, and metals like Aluminum from the lunar soil.
There is In-Situ Resource Utilization (ISRU) related to water-ice and other materials in lunar Permanent Shadowed Regions (PSRs) and extracting O2 and metals (or metalloids) from regolith in the illuminated terrain.
There is effort to make efficient extraction of oxygen and metals.
Molten regolith electrolysis – which processes melted lunar soil to extract the metals within – is one of the leading processes for in situ resource utilization of lunar metals and oxygen.
If humans are going to establish a long-term presence on the Moon, they’ll need resources – and more than just water and oxygen.
They’ll need metals, minerals and other materials sourced not only from Earth but also the lunar surface itself.
“It’s so expensive to land materials on the Moon if you’re bringing them from Earth,” said Kevin Cannon, assistant professor of geology and geological engineering at Colorado School of Mines. “The cost to get anything down to the Moon is about $1 million – per kilogram.”
“But if you can just bring the factory, so to speak, and source all the raw materials from the Moon’s surface, you would eventually save on the cost of what you need to bring from Earth.”
Mines researchers will develop a tapping system that can siphon off the molten metals from the MRE reactor. That system will be integrated with an aluminum-refinement reactor and a wire-casting system to create high-purity aluminum wire that could be used as a feedstock for additive manufacturing on the surface of the Moon.
“Aluminum is commonly used on Earth in many different applications. On the Moon, we’d be interested in power transmission lines – if we wanted to collect solar power and create a grid, aluminum is one of the best materials for that – and we could also use it to make solar panel frames or spacecraft parts. It’s a very versatile metal and there’s a lot of it on the Moon, but it takes a lot of energy to liberate it.”
One of the key questions the researchers hope to answer is material compatibility. In order to function on the Moon, the reactor will need to be made of a material that can withstand the extreme temperatures required to melt the regolith, keep its strength and not get corroded by the lava.
National Science Foundation and NASA have provided Lunar Resources ~$3 million in funding to develop a prototype reactor that could be sent to the Moon for a demonstration test. The demonstration reactor will be ready to fly before 2024.
Lunar Resources is making a Molten Regolith Electrolysis, by which lunar regolith is heated to a temperature of 1,600 degrees Centigrade, melted, and then electrolyzed to produce oxygen and metals, such as iron and silicon. Although the composition varies by location, lunar soil is composed of about 40 to 45 percent oxygen, 20 percent silicon, and 10 percent aluminum, with smaller amounts of iron and titanium.
All the materials are there to produce silicon solar cells, transmission cables, power storage, and more to provide power to lunar settlements during the 14-day lunar night.
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.
Please pardon me … “Y A W N”
A 3-D modeled, then ray-trace rendered graphic of an inverted tub with pipes attached hardly evidences an electrolytic metals separator. Just as a first glance, knowing what I do about electrolysis (a bunch!), there’s the missing infrastructure of the electricity needed for electrolysis. A tremendous amount of DC energy, relatively low voltage (on the order of 15 to 30 volts) at staggeringly high amperage (tens to hundreds of thousands of amps).
This level of energy, here on Planet Dirt (“Terra”), is commonly and critically used 24 hours a day, everywhere that there’s abundant cheap energy, to make good old Aluminum metal. Every last milligram of it in your soda cans, preppy water bottles, aluminum foil, pie plates, endless lightweight doodads was produced by this route. We KNOW electrolysis, here on Dirt.
Again, trying NOT to be a cynic, but obviously a whole lot of electricity is needed.
Let me give you an idea how much. 15 kWh per kilogram of Aluminum via the Hall-Heroult process. This excludes the electrical investment in first purifying the aluminum ore to fairly pure status. And the process of mining it out of ore bodies. And all the transportation costs. Just the 15 kWh that goes into the electrolytic cells. Over 50% of the electricity goes to heat: this is not a bug, but a feature, since the produced heat keeps the reactants molten, AND keeps the aluminum pooling at the bottom of each cell. Molten metal is happy metal, in electrolytic reactors.
So … speaking of molten metals (aluminum serves as its own anode, being metallic, a good conductor, and always present in the bottom of the reactor), we need to think of the ‘other guy’, the cathode stuff. Hall-Heroult cells (oh, go lookit up on Google or Wikipedia already!) are made from big honkin’ walls-and-floor of graphite. Conductive carbon. The cathodes are also made of graphite, but get ‘eaten up’ by the produced oxygen, it being momentarily in its atomic state (instead of normal 2-atom molecular), and wants more than anything else to find a dumb, close-by, also-reactive atom to bond to. The graphite becomes CO₂. Happy, happy, joy, joy.
Where’s all this graphite going to come from? Ah, yes. Terra, the dirt planet. Oh sure, you counter: there’s plenty of carbon (we think) on Luna due to the eons of carbonaceous chondrites (meteors) that have impacted her, well, since time began. But… like the given-to-be-plentiful aluminum ore, it is all jumbled up with, well, everything else of any value. Jumbled up quite determinedly. Billions of years of meteors have had their way doing that.
Well, OK, let’s be positive! All the separation which is going to HAVE to happen to get the various ‘ores’ separated into piles will be producing a ‘carbon pile’ along with all the rest. Eventually there’ll be enough of it to heat up, free from most of its volatile distracting compounds (which have their own flasks and piles to go to, being useful too), and more graphite can be made ‘in situ’ as they say. Cool! Graphite sales from Terra can end.
Still, I’m struck by the fact that at least for quite a while (very likely many years to decades), it’ll be way, way cheaper to make all the electrolysing graphite tubs on Planet Dirt. The aluminum will be quite handy for conducting electricity and building all sorts of infrastructure. Buildings, roadways, bridges, pots and pans. Lol.
And the electrolysing will — per the advertisement — also be producing plenty of other volatiles and metals. Lots of nickel, lots of iron, a bunch of titanium (maybe: it doesn’t like being made without chlorine), lots of calcium, magnesium, those kind of things. And a whole lot of power. 15 kWh – minimum – per kilogram. (Aluminum is the ‘most expensive’ from an electrolytic power consumption point of view, it being trivalent, or ⊕3 charged in its oxide form.)
________________________________________
Personally, I expect the electrolytic plant to be anything but a cute little rounded pod. Its going to look ‘industrial’, with pipes, chutes, hoppers, piles of products; its going to have endless robotics, heavy lifters, people and AIs to keep cleaning it, unclogging it, unjamming its sluices and separators. Will it produce aluminum? YES! Plenty of it so long as plenty of electricity is available. Plenty. And that in turn will be feedstock to the ‘things making’ industries that also necessarily need making. EVEN IF those industries are a far cry from Earth’s equivalent factories … utilizing direct sintering of highly ‘sticky’ powders as the primary manufacturing method. Additive making.
There’s no substitute though for metal ‘working’, in the more traditional sense. The heating, squishing, pulling, hammering, fast cooling, and slow annealing of various metal alloys is critical for developing 60% to 90% of their strength. Some alloys don’t benefit, but many do. So, while outside the scope of this cute pod’s article text, more conventional materials processing will also be needed.
Since copper is pretty rare (armchair research shows) on Luna, then electricity conduction will have to primarily be aluminum based. The production of it locally is an EXCELLENT early-lead process to refine. Extraction, refining, all that too. May well be the most important reason for industrially developing Luna: to industrially build up other parts of Luna. Everything depends on local sourcing ultimately.
The largest really-useful byproduct of electrolytic smelting though is also the oxygen, carbon dioxide CO₂ and other electrolytically ‘freed’ gasses. Humans will use a lot just for existing. And for agriculture. But again, the whole industrial side has plenty of uses for things that you and I and the next donut eater ever gets to actually use, daily.
So…
Better, more complicated graphics would be a start.
And LOTS of electricity generation. Did I read ‘nuclear’ from someone else? Yep, that, too.
⋅-⋅-⋅ Just saying, ⋅-⋅-⋅
⋅-=≡ GoatGuy ✓ ≡=-⋅
“Aluminum is commonly used on Earth in many different applications. On the Moon, we’d be interested in power transmission lines – if we wanted to collect solar power and create a grid…”
Or we could be smart and just avoid the two week nighttime and go with nuclear power. The Moon is a harsh place for solar power on many levels. Two week long nights, direct exposure of solar panels to solar ionizing radiation, etc.
Say it with me… nuclear power.
My view: We need to accept the probability of the Starship fleet landing cargo starting in about 3 years. To reduce cargo missions to the Moon, we need to produce rather large quantities of metal starting in about 5 years.
1% of the lunar highlands is unoxidized metals from micrometeorites impact crucibles. Beneficiate that as your source of metals not the oxidized metals in the regolith. It would take significantly less energy to produce a kg of metal from the beneficiated unoxidized metals than the approach that NASA seems to favor.
We can develop large scale processes on Earth for use on the Moon to be delivered by Starship. Small-scale demonstrators using more energetically expensive methods will, IMO, result in an unnecessary delay.
Transporting material from the moon to Earth’s orbit would be cheaper than transporting it from the Earth. Also separating the Lunar regolith into metals and O2 should be used to turn it into rocket fuel for hybrid rockets.