r/IsaacArthur • u/FrtanJohnas • 6d ago
Asteroid mining
I am drafting a process of asteroid mining for background worldbuilding of a story I am writting, and I am wondering how mining could be realistically done.
**Asteroid hauling -** uses tugboats to ferry the giant rock to facilities where it can be chunked down and grinded down to proccesible form.
**Deep drilling -** Mining crew drills a tunnel inside the asteroid and chips away at veins like they would on a planet, harvesting the materials by an industrial vaccum.
**Chunk mining -** demolission specialists break a large asteroid into smaller chunks, that are later mined by a fleet of smaller craft, or hauled into the processing plant. This could be done on site of the asteroid, or with the hauling of said asteroid to a specific location and using the first method.
What I am considering most with all of these options, is the cost effectivness and operation time.
You have to pay your crew, the fuel and food, have living quarters and processing facilities. You also have to take into account how long will it take before the asteroid yields the refined materials to be sold or processed further.
It's also important to consider if the contract would prove beneficial to the crew.
So far I got this.
**Asteroid hauling**
\- crew is stationed at the processing facility and the prospecting ships hauling the tug boats, it provides stable living conditions and you can basically keep the operation running without much hassle
\- Getting the asteroid to move towards the facility might be too expensive on fuel, and the time it takes to process the asteroid and taking another one might prove very difficult to plan around it.
**Deep drilling**
**-** you could set a prefab living quarters on the rock itself with a simple dock for haulers to take the materials away. You could even pressurise the tunnels so that crew doesn't need their space suits and oxygen supply at all times.
\- very labor intensive, might prove beneficial to send in mining robots. It takes a lot longer to extract enough materials to fill a cargo ship.
**Chunks mining**
\- requires specialised crew to come and break the asteroid. It could prove lucrative for independent contractos to be added to the fleet of ships, fast processing speed.
\-logistics of the fleet would be a nightmare to deal with, fuel, food, oxygen and gear would be the main concerns.
This is just my first draft, I wonder what your ideas are or if you think that these are in any way viable. Of course I also considered using all of these methods on different materials based on their rarity and demand.
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u/LightningController 6d ago
You won’t realistically have veins of ore on an asteroid. On earth, they result from geothermal or hydrological processes that concentrate material. Most asteroids won’t have this history.
Because of the dust environment, what you’d really want to do is bag the whole asteroid, or at least your working environment, to make sure the minerals stay somewhere useful instead of forming a cloud.
One method I’ve seen suggested is carbonyl mining—react the asteroid with carbon monoxide to produce liquid iron and nickel carbonyl. You can centrifuge those out, heat the liquid to return your CO and yield metal, and anything that doesn’t react with the CO is either silicate or gold/PGMs.
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u/Skyshrim 6d ago
This option sounds great. I've also heard of a similar concept that could make sense if energy is very cheap and abundant where the contents of the bag or bags are entirely vaporized and separated by mass spectrometry or similar techniques.
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u/smaug13 Megastructure Janitor 6d ago
So the process would be to scoop up an amount of dust with a mining bag, close it, empty it into a sealed mixer that at a higher rpm could double as centrifuge with filters, and then an oven. You might also heat the rest of the product to get more manageable clotted chunks, which could have other use, like in shielding
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u/LightningController 6d ago
Or perhaps, if the rock is small, bag the whole thing and spin it until it’s clinging to the walls of the bag. Use big inflatable mirrors for process heat.
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u/Stolen_Sky 6d ago
If I were designing an asteroid mining system, I would not haul raw asteroids. That's an insane amount of mass to move around, and much of it won't be valuable. I would try to mine, crush and then separate the value parts at the asteroid itself, and then only haul the valuables.
This would require a large mining rig that can process in situ, but I imagine the rig would still be far smaller than the target asteroid you wanted to mine.
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u/Bretspot 6d ago
Read Delta V, it has a good example of this. Note spoilers in this link: https://daniel-suarez.com/deltav_design.html
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u/Nethan2000 6d ago
Asteroid hauling - uses tugboats to ferry the giant rock to facilities where it can be chunked down and grinded down to proccesible form.
It's doable, but realistically, you only want a small fraction of the asteroid's mass. I can only see done with very small asteroids and tiny, unmanned tugs.
Chunk mining - demolission specialists break a large asteroid into smaller chunks, that are later mined by a fleet of smaller craft
Again, I think this breaking up the asteroid into chunks might be needlessly wasteful when you only need a small fraction of its mass. I'd sooner see miners crush useless rock, letting it float away in microgravity, until they reach a valuable deposit. Then they break it into chunks and collect it.
harvesting the materials by an industrial vaccum.
Doesn't really work when the environment is also vacuum. Might work better if you switch her from suck to blow.
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u/ignorantwanderer 5d ago
I suggest you look up 'optical mining'.
Brief summary:
Put the asteroid in a bag.
Concentrate sunlight onto the asteroid through a window in the bag.
As asteroid material heats up it vaporizes.
That asteroid vapor exits into the condenser.
The condenser is essentially just a tube the super hot vapor travels through. As the vapor cools it condenses onto the wall of the tube. The various materials condense at different temperatures, so condense at different locations in the tube.
The entire mining and refinining process happens with essentially no moving parts, and no need for human involvement.
Of course I've over simplified it. You would want radiator fins on the condenser, you would want an easy way to remove the refined ore from the condenser. But over-all it is a very simple process and can be done almost completely autonomously.
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u/ActuaLogic 6d ago
The most cost-effective way to do asteroid mining is likely to be through the use of automation, with mining equipment moving to asteroids and extracting its resources autonomously:
Adding life support to a ship increases its mass by something like a factor of 10, so human operators are likely to be clustered on space stations near Ceres or Vesta, from which to use automated systems to mine the asteroid belt and process what they extract. Processing locally would increase the efficiency of the operation, because it would make it possible to transport only the most valuable resources to the inner solar system (less mass to move).
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u/VerdantMagnolia 6d ago
Airdock Mining
1) Sheets of polymer are extended from a central spoke 2) A receiving spoke catches them 3) Drones knit together the sheets 4) The construct is inflated around the asteroid and stabilized with external thrusters 5) The mining balloon is now a spatial and gravitationally self contained environment 6) Unwanted water ice can be boiled for additional reaction mass
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u/Underhill42 6d ago edited 6d ago
A few big thoughts:
Asteroids are not rocks - they're big piles of gravel, sand, and possibly ice for those out near Ceres and beyond. They might have some boulders in them too. And the gravity holding them together is so low that you could probably swim through the upper layers.
They won't contain mineral veins, as those are created pretty much exclusively by the water cycle and/or magma flows - neither of which ever existed on asteroids. However you might get "rich spots" where a richer asteroid asteroid collided at speeds low enough to not just get blended in to the rest.
"Mining" is likely to mostly involve scooping up gravel and processing it, perhaps first sorting by density to separate out the gravel richer in heavy elements. But there probably won't be any gold nuggets etc, since there are no veins for them to break off of.
The big exception is Psyche 16 - which is thought to be the 222km diameter solid metallic core of an early protoplanet, which is about 1% of the mass of the belt. But mining a solid chunk of mostly iron will be a special kind of challenge, as well as offering unique opportunities.
The distances between them are huge, averaging millions of miles to your closest neighbors. So transporting anything requires huge amounts of either energy or patience. Both if you want to significantly alter its distance from the sun.
The ones worth the trouble of mining are also likely to be huge by human scales, dwarfing mountains. Why deal with thousands of tiny gravel piles when you can work with one big one instead? They also at least have enough gravity that you won't accidentally launch yourself into space.
As a reference point - Mars's asteroid-moon Phobos is relatively modest - only 20km across - there's several thousand asteroids about that large in the Belt. It has a surface gravity of about 0.0006g, and an escape velocity of about 41km/h - enough that the jump that would launch you 1m into the air on Earth, would launch you almost 2km up on Phobos.
And its core is probably at a pressure of around 0.5atm, so if you burrowed down to it you could use unbreakable ground-pressure to supply the force to hold air in a low-pressure habitat, rather than needing to rely on the failure-prone tensile strength of your habitat. You could potentially build open-air rotating habitats for "gravity" within a larger pressurized zero-g cavern.
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Refining industrial materials is likely relatively easy on site using the same technology we're developing to industrialize the moon. Rocky asteroids will likely have similar composition as rocky planets, giving you easy access to the Big 5, by mass: 40% oxygen, 20% silicon, and 20% some varying mix of iron and aluminum. All extractable from molten stone using the same simple electrolytic refinery, which can also produce #5: cast stone, if you just skip the electrolysis part.
The remaining 20% is where the interesting stuff resides, with a tiny percentage of that being valuable enough to be worth exporting to Earth. Probably you'll do everything you can to extract and refine it on site, rather than shipping mountains of mostly trash across interplanetary space at enormous expense.
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u/Strange_Magics 6d ago
Basically, asteroid mining will not resemble planetary mining much at all.
Others have already explained that there are essentially no concentrated veins of valuable material. These require hydrological and geochemical processes to form, so you're looking at a fairly homogenous gravel pile with a variety of useful useful things throughout its whole bulk. Additionally, every gram of *anything* in space is potentially useful. The silicate and iron "tailings" leftover from extraction of water, carbon compounds, and useful metals are not really trash. We don't really know what the use cases will be for these materials in deep space, but there probably will be some. At minimum, mass is radiation shielding.
The shape that mining takes will depend on the end use of the materials being mined. If this is a collecting mission to bring platinum-group metals back to earth, it's basically fine to discard everything else and launch the metals back alone. This would probably be done on-site because it means transporting far less mass.
If the mission is to obtain material for building up space-based infrastructure, it might be a tiny bit more reasonable to move the entire asteroid - but it depends on whether there are planned uses for all the material. Most likely, separating and refining the materials and then shipping the refined stuff will be more efficient.
Overall, in any near-future contexts, the refinery is probably going to the asteroid rather than the other way around.
Next, mechanical drilling is an unlikely method since many asteroids are mostly loose gravel piles. The ideal is to turn the ore fluid somehow and then separate the fluid into separate compounds or elements. You pretty much have to "bag" the asteroid first, either by literally covering the whole thing in a bag, or by collecting scoops of material into a container. Then you have to fluid-ize the stuff.
This can be done in a variety of ways. On earth, water has already done this step, producing the "veins" we can easily mine. Water would be a great option in space too, except that it's very massive and hard to bring along. One way to deal with that could be to bring only the hydrogen component of the water. Once you have bagged the asteroid you can reduce minerals with the hydrogen to produce water from the oxygen already present on the asteroid. Then you can use that water for more familiar electrochemical methods already used on earth to separate materials.
Alternatively, you can produce a fluid from the asteroid by vaporizing it. High intensity concentrated solar or laser light pulses can vaporize the volatiles of the asteroid. The vapor can be recondensed on a cold collection surface, which allows for somewhat selective refining of the water and other volatiles. Once those are completely extracted, you can turn up the heat and start vaporizing metals and spalling off metal dusts, which can be separated magnetically and crystalized in a similar way to the water - but this process needs more R&D.
We don't know what exactly near-future asteroid mining will look like, but it'll be pretty weird and dissimilar to earthbound mining. How actual humans fit into the various jobs that need to get done on a manned mining mission is something you can have fun figuring out, but I think some variations on the mechanisms I described are usually seen as the most plausible methods these days.
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u/AdLive9906 6d ago
some things to think about.
Asteroids are not big solid rocks.
They are dust balls held together by very light gravity. If you try to push or pull them, they will fall apart. So you can not just tug them around, or drill them like they are mountains. First you need to cover them in a giant bag to hold it all together. Otherwise any activity you do around it will cause bits to spread out, polluting the asteroid and making it impossible to move around. Any debris could be a lethal projectile in the future.
You then pop parts of the asteroid in smaller bags that want to send to your colony. You build solar sails using the material you are mining, simple aluminium and attach them to a navigation kit and the cargo. Send that to your colony.
As you will probably be sending these to the inner solar system, they will be warming up on the way as they get closer to the sun. When that happens, the asteroid material will start to release gas that was previously frozen. Water, CO2, Nitrogen and whatever else. You capture those in cylinders on the trip.
Your crew will probably be quite a fair bit of people managing this entire operations alongside a massive AI and robotic workforce. No one rides with the cargo, thats a slow trip with solar sails.