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Against all odds, an asteroid mining company appears to be making headway (arstechnica.com)
154 points by bookofjoe 74 days ago | hide | past | favorite | 177 comments



Asteroid mining only makes sense for constructing things in space. For applications here on Earth, the logistics of both leaving and re-entering the gravity well mean that it will never, ever be economical for anything other than materials that literally don't exist on Earth. Bringing platinum and gold from asteroids to Earth doesn't make economic sense, let alone iron.


If any of these asteroids have water ice buried that might be a good start. Easier to refine water and carbon into methane for fuel depots in space than other applications. Also drinking water, splitting for hydrogen or just use the ice as a radiation shield all are near term applications that don’t require lots of supporting infrastructure.

I suspect that near term they might make some decent money just returning small samples for labs to analyze. If they can figure out how to do that economically they can likely survive off of grant money from various government entities. Contracting their asteroid lander for various science missions is also a good opportunity.


I remember reading an article from back when Blue Origin was a space mining concern that the first thing to grab is water just to supply the space station. Because it’s so expensive to take water into orbit and retrieving a comet or something else was fairly cheap and could yield billions of water for use by anyone in orbit.


Yup that is how I would do it. Water sample returns to labs > water mining > platinum/gold/etc.


I don’t think this is categorically true. A couple obvious options are constructing titanium gliders to land materials on earth, and de-orbiting incoming metal loads with a space tether to provide inertia that can then be used to launch planetary loads to orbit.

It’s true that the relative value of these materials will be higher in space (since your alternative is lifting it out of the gravity well) but there may be so much supply that you can saturate the space market and justify the extra transport cost to sell it on earth too.


Or most likely in today's scenario, demand is miniscule in space compared to earth's so you sell on the earth market while demand in space materializes.


If you make water cheap in the orbit, and have capability to produce fuel... it would drive investments into space through the roof.

Suddenly you only need to get to orbit, as everything else is cheap, because you can refuel and get water. You can go where you want to go, you can grow food, you can stay in low earth orbit for cheap.


Suppose one of the things you construct in space is a skyhook. The economical way to operate one of those is to bring down as much mass as you bring up, that way the net change in angular momentum is 0. This would change the economics of bringing space-materials down to earth.

That said, we're a long long way from being able to build a skyhook. I'm only objecting to the "never, ever" part of your post.


> I'm only objecting to the "never, ever" part of your post.

Sure, let me qualify "never, ever" as having a time horizon of "so long that anyone claiming that you, the eager investor, will see an economic return on this endeavor in your lifetime is secretly banking on breakthroughs in life extension technologies to make that statement technically correct".


"within your natural lifespan" isn't really a qualification of "never, ever". The two are very different time frames. I think it's good that you're willing to adjust your opinions given new information, but it would be nice if you admitted that you changed your mind based on what MatrixMan said instead of acting like "within your natural lifespan" was your original intent.


Or alternatively, they was using hyperbole as a rhetorical device.

If you read the comment sympathetically, it is definitely possible to infer that was their original intent. In fact, i think its the most reasonable interpretation.


Every prediction about the future--this one, every other one ever made, and every other one that will ever be made--is implictly made under the assumption that if the prediction lies beyond the predictor's lifespan, then the predictor will not be in a position to care one whit about the veracity of the prediction when that time comes. My clarification isn't at all motivated based on what the parent commenter said (I find the construction of a skyhook approximately as likely as the construction of a space elevator, which is to say, it will "never, ever" happen), but rather as an explicit clarification of the aforementioned implicit assumption.


My trouble with this definition of never ever is that it prevents us from starting on endeavors that may take a long time--a self fulfilling prophecy.

We may never ever mitigate our climate concerns, which obfuscates that it is a choice we'll have made, not an inevitability.


What would you say to someone who claims that "never" obviously means "not before the end of this quarter, cause who could possibly care about anything beyond that"?


Why does it matter whether their caring about whether their prediction is correct, is done at the time that their prediction is about?


Why does the time horizon matter? Imagine I own an immortal goose that lays a golden egg every 100 years. I may not live to see an egg but I can sell the goose based on the expected future payout. A bank could invent some financial instrument that pays me 1/100th of a golden egg every year for a fee.


This neglects the cost of extraction. In particular, the most rare (and therefore precious) commodity in the solar system and indeed the universe is the 4 billion year old bioreactor we refer to as "topsoil".

Getting all the other elemental material we need without screwing that up will be a win for our descendants.


The topsoil lost from mining is miniscule compared to other causes. Most mines aren't even located in places that could be used as productive farmland.


Perhaps not productive farmland, but lots of forests have been cut down and have been proposed for deforestation to support mines


Far more forests were cut down to produce iron and steel, post-mining.

Thankfully, forests are self-renewing, and we no longer use charcoal as a carbon source.

Mines are also generally pretty small compared to forests.


Some points for you to consider:

Charcoal is very much in use around the world, forests are now small enough that entire forests are marked to make way for mines, and forests are not-self renewing on time nor does a mine convert back into a forest.


4,620,000 kg of raw wood to equip a standard Roman legion with iron/steel is a lot of wood.

Charcoal is no longer used as a primary heating source in the way it was in antiquity, given the global trade in oil, gas, and coal.

Furthermore, mines in civilized parts of the world generally do have reforestation requirements as part of their decommissioning.

We can certainly gripe about the legacy of toxic tailing ponds et al., but tree cover is usually handled decently.


We are then talking about different parts of the world. I am biased by what I see in India.


I dunno, Dragon's return capacity is 3000kg which is about $240m... I think if there was a giant sack of pure gold bars up there it would be economically viable. The problem is there isn't. No way are you going to be able to refine it in space either.


It might not be so hard to do because space is such a good insulator. You could get two chunks spinning on a tether and use a solar pumped laser to heat them. It would be a sort of melting-point chromoatograph where you'd get different materials melting out at different times. Cooling the collected material would be expensive, but you'd end up with most of the gold all together in one stratum of the result.


"It would be a sort of melting-point chromoatograph where you'd get different materials melting out at different times."

In geology, we do something incredibly similar called the Bowens Reaction Series. Take a bunch of stuff, melt it and cool it, watch what precipitates and crystallizes from the melt in order to determine the overall composition.


> Cooling the collected material would be expensive

Can't you just throw it in the shade and wait? Space is an excellent insulator, but radiation cooling still happens. Just let it sit there for a few weeks/months and you're all set, right?


I think you're right. I've been thinking in terms of vehicles with habitats, where the conductive heating would eventually be a problem. But this is just a few buckets on a cable, the whole assembly can stay at molten-metal temperatures for weeks without hurting anything.


Indeed, I'm referring to the cost of the whole operation, including all the bits where you need to develop and deploy a fully-autonomous robotic mining operation a zillion miles from anywhere.


Why would you return the materials in Dragon? You can build a simple glider from space-side materials. The return trip is way easier than getting out of the gravity well. You don’t even need crew.


Bonus points if you design the glider in such a way that it is covered in some sort of ablative material that helps mitigate climate change after it burns off keeping the mined material from doing so to maximize material return.


This is an interesting idea. I initially assumed you’d just structure your payload (eg titanium) to ablate during reentry.

But maybe you can do something better with carbonaceous asteroids, or simply with regolith, to produce a cheap ablative shield. I suppose the problem would be with the changes to aerodynamic profile during reentry - but perhaps regolith tiles could be manufactured to ablate in a consistent-enough pattern?


You can't glide back to the surface. Kind of feels like you should be able to but it doesn't work out like that. If it did then that's how all spacecraft would descend.

Scott Manley did a good video about it.

https://youtu.be/5kl2mm96Jkk?si=Uf9ntP6R39SJrVBm

Skip to 3:45 for your exact "well meaning suggestion from people who aren't rocket scientists".


Scott is debunking ideas to dump deltaV before hitting the atmosphere, to avoid having to go through the rigors of reentry. This isn’t relevant to the discussion; he’s not disproving the possibility of landing from orbit in a glider.

The existence proof here is the shuttle, which did indeed manage to glide from orbit.

The challenge is that you need some strategy to dissipate the kinetic energy on reentry. The approach that both the shuttle and these hypothetical gliders use is ablative heat shielding.

A glider manufactured in space and autonomously piloted would have a lot more design space to explore, since you don’t have the constraint that it has to be launchable on a rocket, and you can potentially spend years on successive aerobrake approaches if that is optimal.


As I’ve continued to read I realize the shuttle didn’t have ablative tiles, rather reusable heat dissipation tiles. Better aerodynamics, so maybe our glider should use this approach; the Si and C required are present in asteroids, but manufacturing is space could be challenging.


When the vehicle disintegrates on reentry like a shuttle sometimes does, who gets the platinum?


Uhm yes he is. You didn't listen to the whole video did you?


I listened to the whole video, and the parent understands this better than you do. The video doesn't say that gliders are impossible, period. It says that slowly gliding down, without a heat shield, is impossible. As the parent noted, the Space Shuttle proved that quickly gliding down with a heat shield is possible and very realistic. The video doesn't claim anything to the contrary, of course.

It's a good and important point that the term "glider" needs to be qualified. But you failed to make this point.


Return trip is double the complexity as first you need to get there. And then you need to slowdown to get back here as into orbit. Getting off the Earth is somewhat solved. But getting there and back at scale is not really done.


Smelting using focused solar radiation against a spinning carbon crucible would be cheap, mechanically simple, and effective. I’m not sure why you think you can’t refine in space.


Smelting is for extracting metals from oxides or sulfides. It can be used on the Moon or on Mars.

It does not work for asteroid mining.

There you have just pieces of iron with a low content of alloying elements.

Among the alloying elements, nickel is the most abundant (17.3 times less than iron), then cobalt (20.9 times less than nickel), then germanium (20.4 times less than cobalt).

The precious metals that would justify the mining operation are present as a few grams each for a ton of iron.

Melting the alloy will never separate the metals by itself.

However perhaps some kind of floating zone melting could enrich the proportion of precious metals in a part of the iron, but it is very unlikely that a high enough enrichment could be achieved by a reasonable number of zone melting passes.

On earth the cheaper metals could be dissolved by an acid solution, but on metallic asteroids you have neither water nor acids.

The SciFi solution would be to vaporize and ionize the metal alloy and separate the metal ions by their specific charge, like in mass spectrometry.

This would need a lot of energy, but at least it does not need reactants and it is the only method that achieves almost perfect separation.

However for now, the throughput of such a ionic separator is extremely small, too small for industrial production. Perhaps it will become possible to scale such ionic separators to acceptable productivities.


Yes I was actually thinking of a gaseous centrifuge process. It would require turning the metals into a gas yet not ionizing them and venting the iron gas into space leaving an ever enriched gold. Realistically you don’t need to enrich to total purity.


Unfortunately that does not work, because these metals are among those with the highest boiling points, even at very low pressures (which is why the oldest solid objects that have formed in the Solar System, at its very beginning, when it was still very hot, have been refractory grains of platinum-group metals with tungsten and rhenium; their condensation has been followed by that of refractory minerals with high content of oxides of aluminum, calcium, titanium and zirconium; and only after additional cooling by the mainstream condensation of silicates and iron alloy).

There are no materials from which you could make a centrifuge for gaseous osmium and iridium.

Vaporizing the input metal with an electron beam and ionizing the vapors allows after that contactless interaction with the ions, using electric fields and magnetic fields, guiding them into separate condensation chambers (which need strong cooling).

The ionic current of such separators must be increased several orders of magnitude over those currently existing, for this to become a viable separation technology.


Except we are talk about iron and gold not osmium or iridium. Iirc carbon ceramics like hafnium carbide have melting points significantly beyond the vapor point of iron?


The main valuable content of the metal alloy from which metallic asteroids are made is given by the platinum-group metals, including osmium and iridium.

Of all metals that could be extracted, osmium and iridium are those for which there is the greatest difference in abundance between the surface of the Earth and the metallic asteroids.

If the temperature is not high enough to vaporize the platinum-group metals, they will remain as solid grains, which are likely to damage any centrifuge.

Making a centrifuge from a ceramic material like hafnium carbide is unlikely to work, due to its fragility and low tensile strength, especially at very high temperatures. A ceramic coating of the parts in contact with the hot gas might work, but even if there is a lot of experience in making such things nobody has made parts working at temperatures so high as needed for this application.

The problems for making such a gaseous centrifuge are similar to those for making a high temperature gas turbine.

During the last century, tremendous resources have been dedicated for increasing the maximum temperature of gas turbines. The working temperatures have been slowly increased, but more and more slowly in recent years and there is very little hope that it is possible to increase the working temperatures much beyond what has been already achieved.

A metal separation centrifuge would require working temperatures not higher by 10% or by 50%, but temperatures at least 3 to 6 times higher than for the existing gas turbines.

Based on the existing experience in improving gas turbines, I believe that this separation method can be safely dismissed.

While a centrifuge is not feasible, there are chances to use a part of your proposal.

Heating the metal alloy at a temperature high enough so that iron will sublimate quickly (together with nickel, cobalt, gold etc.) while platinum-group metals will sublimate very slowly could produce an alloy highly enriched in platinum-group metals with a mass many times lower than the starting mass.

This method cannot separate any individual metals and it would lose the gold and other possibly useful components, like germanium, gallium or cobalt, but it could reduce the mass enough so it may make sense to take the concentrated alloy with platinum-group metals away from the asteroid, to a place where it could be processed with more selective methods.

While such a method has some small chances of being profitable, it is very wasteful. Real asteroid mining must separate the metal alloy in all its components, because all can be very valuable, less for being brought back on Earth, but for building any kind of structures in space or on other planets/asteroids.


Thank you this was very informative and helpful.

Another idea, taking advantage of the vastness of space and relative masses in another way. Rather than containing the gaseous material could you not vaporize a large amount of material and linearly accelerate it at the same time by a fixed amount. Maybe even a high powered laser could accomplish both at once without physical contact, or a laser combined with a magnetic field. The mass of the heavier metals will mean their ultimate velocity will be significantly less than the lighter ones. Over some distance they would condense back to liquid then solid but would have striated and continue to separate in distance as the relative velocities continues to pull them apart in distance. You could even do this by producing a pulsed beam of material moving towards earth from the mined asteroid. Closer to earth you would collect material in order of arrival and separating them into bins by expected relative arrival time by elemental mass. Would this not lead to a pretty refined mixture and require no physical contact?

To your point about the sublimation points being different slowly heating the material while applying force to the vapor would also increase the separation in space, and leaving some highly concentrated high vapor point platinum group residual alloy to be refined on earth - maybe this would be considerably less wasteful as you would capture everything at the collection point relatively separated with no exotic materials or centrifuges?


Because right now it's not even research, let alone economical. This isn't Stellaris, this is real life.


I see, so when pursuing future technologies we should stick with what we know? We typically research what’s achievable in the near future, however the mechanics for purifying heavy metals with centrifugal forces isn’t new fwiw. It’s how we made atomic bombs.


[flagged]


Yes. 80 year old technology trying to do something much more complex than separating two very distinct elements.

I’d remind you you’re commenting on an article about asteroid mining, which is sci-fi that’s becoming more attainable.

What I don’t really get is the nasty hostility.


Tone policing is a weak retort. If you'd rather we just sing Kumbayah and talk about science fiction then yeah! We could even staff these centrifuges with autonomous bipedal androids a la Lt. Commander Data. Those are becoming attainable in much the same way as your mechanically simple, cost effective, never been built zero g metal gas centrifuges. Learn something with that big brain of yours.


No, I’d rather people just not be assholes but some are simply incapable of it.

I’d note you’re responding in a thread about asteroid mining becoming more attainable, at a time of large language models in the last two years being able to remarkably emulate natural language beyond anything dreamed of three years ago, with low earth orbit lift a commodity orders of magnitude cheaper as we work towards a moon base, in the final stages of preparing an interplanetary starship built by a privately owned company whose owner wants to personally colonize another planet, while humans are only years away from potentially being redundant at driving (and possibly many white collar professions)… and none of that was made possible by people with no ability to imagine a future like yourself. Enjoy your petty and cynical existence of insulting people on the internet while the rest of us make the future you were promised despite you.


Can't we just shape the mined platinum into rods and drop them into the oceans from orbit? Or onto rival mining companies, for that matter?


Often referred to as Rods from God, but Syndicate Wars had the better name: Satellite Rain.



if space fuel is cheap you can just elongate your orbit and at the peak retro-burn to match the relative earth speed. Then release the cargo, it would fall with terminal velocity to earth. and burn with your cargo-craft back to establish the orbit.


Why not make a mostly-empty mesh from mined metals?

Someone talked about 3D printing mostly hollow golf balls in outer space and dropping them onto a desert where they could be picked up .


But once you have that infrastructure in space that can mine and construct in space won't that greatly shorten the supply chain for asteroid mining and bring the cost down?

It seems to me that when people make the kind of argument that you're making they're forgetting to price the negative externalities that Earth based mining cost our society via environmental damage.

If the environmental damage and species decline that we're experiencing from our planet-side economic endeavours were properly priced in space based manufacturing and asteroid mining would look a lot more attractive.


The key to manufacturing is humans. Robots help yet need a lot of human maintenance. Human-free spacecraft require a lot of lead time and still begin from a human touch on earth.

NEO is too resource starved for it to ever be independent enough to be cheaper than just managing resources better on the surface of Earth.


Maintanance is hard, but there is a solution.

Design the robots out of materials that can be found in space. Then make them capable of reproduction. Then you can just scrap damaged robots as long as you can replace them fast enough. This also has the benefit that you just need to send up a tiny bootstrap population, but with time you will have quite the formidable workforce.


Doubtful there are enough resources to sustainably maintain much of anything in NEO. Asteroids with significant reservoirs are far apart and navigating between them is fraught.

Also how are the robots going to know what and how to maintain things? Otherwise they must be remote controlled. Yet their sensors break down over time.

Do reproducing robots even exist on Earth? How robust, nimble, and capable are they? Are their inputs found in space?

All that said, I do love the idea of a robot space colony producing useful things, even if all we gain are space probes and knowledge.


Robot production on earth is entangled with the whole global supply chain. I do believe many of the steps are automatic or semi-automatic.

It's """simply""" a matter of separating taking all those steps and separating them from the whole, packaging them into a bunch of boxes and sending them to space.

So in other words it's incredibly complicated... but possible.


You may find this link interesting:

https://en.wikibooks.org/wiki/Seed_Factories


Kind of a hand-wavy solution here - don't worry about maintenance just invent a self replicating universal tool that is either perfectly recyclable or cheap enough that we don't need to worry about their resource costs or cleanup. With that kind of tech nailed down pretty much ANY endeavor sounds very achievable (until the cheap startup version cuts one too many corners and the gray goo scenario begins I guess).


But isn't it just the natural progression of innovations like interchangeable parts and assembly line manufacturing?

And isn't it already a thing that we're progressing to with increased industrial output and reduced labour requirements?

This is where we're going, we just need an driver to push us to do it. Space exploration and resource extraction from the asteroid belt/moon to prevent the complete destruction of our environment seems to be as good a driver as any.


Silver is antimicrobial. Gold is highly conductive.

If we had these materials in absurd excess, we could literally build hospitals from silver and the electric grid from gold, and it would be great for our civilization.


Gold is a worse conductor than copper. Silver is slightly better per volume but worse per mass.


Per mass, aluminum is better than copper. That's why modern high voltage lines have aluminum conductors around a steel core, while "advanced conductors" (aka High Temperature Low Sag) densely pack aluminum around a composite core.

https://pv-magazine-usa.com/2023/11/20/reconductor-existing-...

https://haas.berkeley.edu/wp-content/uploads/WP343.pdf#page=...

https://www.entsoe.eu/Technopedia/techsheets/high-temperatur...


It’s better in oxidizing environments.


So basically everywhere under the sky.


Gold and silver is less common in space than here on Earth.


The average content of gold and silver and of platinum-group metals is very similar in the whole Earth and in the rest of the bodies of the Solar System.

Nevertheless, in the crust that covers the surface of the Earth, the abundances of gold and silver and of platinum-group metals are many orders of magnitude lower than their average abundances in the Solar System.

For instance most of the silver has remained in deep parts of the mantle when the crust has formed, so silver is 11 times less abundant at the surface of the Earth than in the Solar System.

Gold and the platinum-group metals have gone to even higher depths, in the iron kernel. So at the surface gold is almost 300 times less abundant than in the Solar System, rhenium almost 600 times and nickel more than 900 times less abundant than in the Solar System, palladium around 3000 times, platinum and ruthenium around 5500 times and osmium and iridium around 50000 times less abundant than in the Solar System.

Similar numbers apply to all of the 8 planets that are big or medium-sized and also for some of the small planets and big satellites, because all these have been melted at some point in their history, when all the metals with high affinity to iron or sulfur have gone to inaccessible depths below the surface of those planets.

In the outer parts of the Solar System, the bodies are covered by thick layers of ice, but for the 4 inner planets the silicate crust that we see covering their surface is similar to the slag that forms at the surface of the iron smelted in an iron furnace and it is similarly depleted in the metals with low electropositivity.


You can also find asteroids that are enriched in platinum-group metals, by that same process. The shattered core of an ancient ("Iron catastrophe" differentiated) planet should be highly enriched in these metals.

16 Psyche might, or might not, be such an object. If so its surface is still covered by a "rubble pile" layer of rocky material.

https://www.space.com/james-webb-space-telescope-psyche-plan...

https://www.freethink.com/space/psyche-asteroid


You are right, but the enrichment of those asteroids in platinum-group metals is very small in comparison with the corresponding depletion of the surface of the planets.

While the depletion has reduced the amount of platinum-group metals by many thousands of times, the enrichment only increases their concentration a few times over the average concentration.

The reason is that the planet cores still include iron, one of the main 10 elements of the universe, the least abundant of which is many times more abundant than all the other elements combined.

The enrichment consists only in the removal of the magnesium, silicon and oxygen from the planet core, while the iron stays there.

Even with all the platinum-group elements in the core, their abundance cannot increase beyond the limit imposed by the ratios between their average abundances and that of iron (actually their abundances become a little larger than those ratios, because a bigger fraction of iron remains oxidized in the mantle than the corresponding fraction of platinum-group metals, but the difference above the average ratios remains very small).


https://www.forbes.com/sites/jamiecartereurope/2023/06/05/go...

You sure about that? Here's just one asteroid made of mostly gold, nickel, and / or iron that's supposedly worth many times more than the entire global economy. Pretty sure that anything we have here on Earth also exists "out there" in much greater abundance than we could ever possibly imagine here on our finite little speck of a planet (except maybe "life", which we only have absolute proof of here on Earth).


> gold, nickel, and / or iron that's supposedly worth many times more than the entire global economy

You hear these statements sometimes about asteroid mining, and they betray a misunderstanding of the way economies work. The reason gold/etc. is expensive is because it is scarce. If we suddenly have an abundance of these materials, then they will be cheap. The intrinsic value of these metals is not worth multiples of the global economy.


For precious metals that doesn't necessarily mean it's not worth going to get them in large quantities. Aluminum used to be more precious than gold. Now we make airplanes out of it.


It's a pretty good example with the difference being energy to retrieve vs energy to refine.

Even with/if there's a 'flood the market' eventuality, you'd have approx multiple generations for the market to grow and mature, improving the associated technologies along the way, and wealth generated orders beyond the Carnegies Rockefellers and Vanderbilts combined.


Soda cans too!


I’ve had an idea for a sci fi story lurking in the back of my head of an earth-based cartel sabotaging space mining to preserve the value of their precious metals. The catch is being able to communicate the economics in a way that’s both accurate and entertaining.


Without giving too much away, you would probably enjoy “Artemis” by Andy Weir.


As long as you double-check it's work, you could always ask an LLM for help with some of that, maybe? I'd install something local like Ollama or somesuch and download one of the larger more popular more recent models and give it an appropriate system prompt related to being a "writing assistant" or something like that. Then bounce ideas off it and maybe throw a few related articles at it for "context" to work with. It's one of the things a lotta recent LLMs are actually useful for and somewhat good at.


Nah, I’m the kind of writer who views using a thesaurus as cheating. I have no interest in LLM nonsense for my writing.


I can sorta understand that, but both a thesaurus and an LLM when used as tools to enhance and extend your own knowledge and skill can totally be a good thing. The problem is that many try to use such things as a substitute / replacement for their own knowledge and skill, to do the actual human creative work part for them. That's where the real fault lies; Not in the tools themselves, but in the user mis-using the tools.

Also, not sure why the prior comment was gettin' down-voted. I'm just tryin' to be encouraging here. If this guy has an idea and wants to write, I'm just sayin' "go ahead and do it then". Why not? Even if nobody ever reads it, if you enjoy writing it, then something was gained.


In the whole Earth the abundances of the elements are similar to the averages of the Solar System, with the exception of some volatile elements, most of them being non-metals, which have been lost in space during the condensation of the Earth and also later.

However the Earth is made of layers with different chemical compositions and many elements are concentrated in layers that are too far from the surface to hope that we will ever reach them. So in the accessible part of the Earth, close to the surface, those elements are seriously depleted.

Some asteroids, unlike the Earth, have never been melted. In that case their composition is homogeneous, similar to the averages of the Solar System. Other asteroids are broken parts from the cores of bigger planets, so they have a composition like in the Earth at very high depths.

However, in the latter kind of asteroids the useful metals are dissolved as tiny percentages in an iron-nickel-cobalt-germanium alloy. This will make their extraction incredibly energy-consuming. On Earth such metals have been separated during millions of years from their surrounding minerals and they have been accumulated as native nuggets or metallic sulfides that are very easy to process for their final separation and purification.

With the alloy that exists in planet cores and asteroids nobody has demonstrated an efficient separation method yet. The laboratory methods used for such separations use huge amounts of water and acids and they will be impossible to implement on an asteroid. Carrying raw metal from asteroids, which is almost completely iron, would also increase the costs tremendously.

So it is absurd to even consider asteroid mining before demonstrating a method that can extract the metals from iron at the mining sites and with a minimum consumption of energy and of non-recyclable reactants.


Thank goodness there’s a lot more space than earth then!


What? Carbonaceous chondrites (the toyota corolla of asteroids) are like .1ppm gold, whereas Earth’s crust is ~0.005ppm

https://pubs.usgs.gov/circ/1968/0603/report.pdf


Carbonaceous chondrites are bodies that have never aggregated into a big planet, so their chemical composition is close to the average composition of the Solar System.

They are extremely numerous, but most of them are extremely small. Changing the spaceship orbit to catch one of them, which might have a few tons only in rare cases, will provide only a few grams at most of useful elements, far too little for the energy spent to achieve this.

Mining a big asteroid that is a fragment of the core of a former bigger planet has much more chances to be worthwhile, but even for that nobody has gives any suggestion yet for how to separate the mined metals from iron and nickel at the extraction place, otherwise the transportation of the raw alloy would also need too much energy.


Bringing stuff down from space is not that expensive with reusable systems like Starship, and this is even more true if you don’t need to soft land it i.e., spray an ablative on a huge rock of precious metals and redirect it to Earth. The delta V costs are quite small. There’s no fundamental physics barrier here.


The going rate for a ton of iron ore is under $100. Pack 100 of those into a Starship, and your gross revenue will be a cool $10,000.


Iron is not precious. Marked to market, 100 tons of platinum is worth $3.2B. That’s a bit more than half the annual world production, so the price would fall significantly, but still easily be more than $1B.


Exactly, and people complaining that the price would fall so it wouldn't really be "that" valuable are missing the forest for the trees. Having a hundred times more platinum available to our civilisation (and platinum being a hundred times cheaper) because there are 200 shiploads of it coming down a year is going to drive innovation & utility in ways we can't even predict yet. Same goes for every other precious metal we can get in abundance from asteroids.


The space elevator will make bringing cargo to/from earth trivial and it will happen way before asteroid mining (current estimates for it being built is 15-20 years)


Wildly optimistic when there is no known material that can be used to build it.


Carbon nanotube is an existing material, manufacturing it at scale is one of the challenges.


Carbon nanotubes are not even close to strong enough to build a space elevator, that's the whole problem. We have no idea if anything that strong even exists, at this point.


Here's a NASA-funded study from the early 2000s, arguing that a space elevator could be built as a paper-thin ribbon at least a meter wide, composed of carbon nanotubes 7cm long, bonded together with epoxy.

http://images.spaceref.com/docs/spaceelevator/521Edwards.pdf

The study also addresses lots of other engineering issues. This work sparked a lot of subsequent R&D that is still ongoing. We're not yet able to actually make the ribbon described in the study, but we're getting there.

Then again, if you're willing to rely on dynamic support, a minimal orbital ring could be built with materials we have today:

https://en.wikipedia.org/wiki/Orbital_ring


From the linked report:

> The material required for construction of the cable is a carbon nanotube composite: currently under development and will be available in 2 years.

Its actually crazy that the report thinks that we would have the necessary material in 2005 and is still used as evidence of a practical space elevator. The graph on page 10 shows the absolutely massive extrapolation from data at the time. It seems disingenuous to even talk final price and time to construct a space elevator (as is done in the one-page brief) without any data confirming the possibility of manufacturing the goal material.


It was definitely way overoptimistic on making the material. But it does present a pretty interesting design, for whenever the material becomes available.


> Carbon nanotubes are not even close to strong enough to build a space elevator, that's the whole problem.

Do you have any sources for that? Because from a quick search online I’m seeing that SE requires a tensile strength of 60-80 GPa and the theoretical max strength of carbon nanotubes can reach 150-200 GPa (with a 63 GPa being demonstrated back in 2000)


Nobody can make a nanotube with a length of one meter, much less with a length of 1 km or of 100 km.

We can imagine a molecular machine that would grow carbon nanotubes like a silkworm grows silk filaments, but we are many decades away from this kind of things.

Moreover, the tensile strength is not all. It must resist to some intentional or accidental collisions, to earthquake waves and so on.


We don't need kilometers. We need lots of 7cm nanotubes, bonded together with epoxy.

http://images.spaceref.com/docs/spaceelevator/521Edwards.pdf


That paper only presents hope that perhaps adhesive bonding of carbon nanotubes could produce a cable with high tensile strength.

It does not contain any experimental results supporting this hope, because only a strength similar to steel has been obtained.

Perhaps it will become possible to obtain a higher tensile strength than with other materials by this method, but it is likely that this will require longer nanotubes and perhaps some other kind of polymeric resin instead of epoxy. It is very difficult to find anything that has high enough adhesion to carbon.


Sure, the material had not been produced yet, and still hasn't. Getting all those long nanotubes to line up parallel is another of the hard parts. It's just a theoretical result.

A key part of the design is for the glue to have a low enough melting point, so if the cable breaks, it melts on reentry and you don't get lots of little fluttery bits instead of a big super-strong cable wrapping around the planet.


manufacturing and building anything out of them in the required scale


15-20 years? I would doubt that range if the process was started yesterday. Any reasonable complex project of closing that scale takes longer time than that. And those have no real unknowns.


CA high speed rail has taken 16 years so far with another 15 on the horizon, and that required 0 novel technology.


I sure hope you’re also betting on a superintelligent ai that can solve every single problem for a 15-20 year timeline


Tether / skyhook seems a more plausible option.


Citation needed. Moving the biggest polluters from Earth to space makes a lot of sense. I am not sure about economic realities.


To be clear, I think there's a lot of reasons to do cool things in space (Moon base, etc.). However, we're kidding ourselves if we think one of those reasons is "make a profit based on the intrinsic economic value of the endeavor".


I think it makes a lot of sense. You leave the earth light and you return heavy and have a gravity assist to return it to earth for free.


Surely reentering is very much not the problem?


Re-entering is a very large problem. Say you've got a few thousand tons of material hurtling towards Earth. How do you get it down to the surface in a useful way? You're not just going to shotgun it raw into the ocean, because then you still have to retrieve it somehow. You're not going to land it with rockets, SpaceX-style, because the fuel costs would be astronomical. You're not going to land it with a short atmospheric drag followed by parachutes, Apollo-style, because the weight makes the energies too great (the Apollo command module weighed about 6 tons upon re-entry). You're going to need something much more sophisticated, Space Shuttle-style, but on a grander scale than ever, and you're going to need to bear the cost of putting that thing back into orbit every time, or you're going to need to develop something brand-new (like a HUGE inflatable re-entry vehicle) or something that exists in the realm of sci-fi (like a space elevator).


Starship has a return capacity of 50 tons.[0] If you have 5000 tons of material to return, that's a hundred Starship flights.

I wouldn't expect asteroid mining to be viable until we have Starship or something like it at scale, doing thousands of launches per year. If most of those flights return empty, then that's a lot of cargo space already available.

Starship uses $1 million in fuel to launch 100 tons to LEO, so half that much should be plenty to take 50 tons back down. But Starship's propellant mass for launch is 2600 tons[1] so that'd be up to thirteen launches to put the landing fuel in orbit. Actually it'd be less, since a lot of the orbital velocity is burned off by atmospheric breaking, not sure how much.

Ideally though, get the fuel from the same asteroids you're mining already. Starship uses methane, so you're just looking for water ice and carbon, both abundant in asteroids.

At current prices, 5000 tons of gold is worth about $400 billion, so it's not obvious that this wouldn't be economical. The world mines about 3000 tons of gold annually and the price of gold has still been going up, so if our asteroid miner returns a couple thousand tons per year it might not crash the price too badly.

[0] https://space.skyrocket.de/doc_lau/super-heavy-starship.htm

[1] https://en.wikipedia.org/wiki/SpaceX_Starship


Gold is the worst example because the price of gold is almost 100% based on its scarcity. Doubling the supply of gold would just cause the price to roughly halve. Hilariously, if you actually had the capability to inundate the world with gold, you'd find it much easier and still extremely profitable to extort the people who own gold to pay you not do so.


You'd make a lot of money on the way to doubling the world's supply. 3000 tons annually just doubles how much we mine, not how much we have; that's more like 190,000 tons. And even if you doubled the total supply instantly, you'd now own half the current value of the world's gold, which would be about $6 trillion.

And of course gold has all sorts of really useful properties, so long term, it'd be worthwhile to make it abundant and cheap.


> Doubling the supply of gold would just cause the price to roughly halve

that isn't the way price elasticity on the demand curve works. that isn't the way any of this works


Does it have to be hurtling toward Earth? How about first parking it at the L4 or L5 Earth-Sun Lagrange point, and then nudging it so it leisurely meanders toward Earth instead of hurtles toward Earth?

That would enter the atmosphere orders of magnitude slower than meteors do. Would that be enough for it to largely survive the fall to the surface either stay largely intact on impact or break up but the pieces would all be in the same general area?


While the interplanetary transfer network is real (https://en.wikipedia.org/wiki/Interplanetary_Transport_Netwo...), getting a payload onto the network itself requires a large and varying amount of energy based on where your asteroid is located. And then once you've successfully gotten your giant rock of solid platinum to some Earth-Sun Lagrange point, you still need to manage its descent to Earth, and beyond the technical difficulties of trying to steer it precisely, the superpowers of the world are unlikely to be peachy keen on the idea of a private company having global orbital bombardment capabilities, which is going to be a political headache of its own.


Heh that's an interesting point. It doesn't have to orbit the Earth, so it doesn't necessarily have lots of lateral velocity to burn off. It'd be interesting to work the numbers for just matching the Earth's velocity around the sun, at a distance of a few hundred kilometers.

Edit: based on a quick chat with Claude Sonnet, reentry velocity would be about a fourth as high, but getting to that initial orbit in the first place makes the whole project significantly harder. But maybe if ablation from reentries became an environmental problem, and deep-space propulsion got really good, it'd be worthwhile.


getting raw materials from space onto the surface of earth intact is such an easy problem that dumb rocks do it literally every day entirely by accident. you just need a low enough sectional density that it loses most of its kinetic energy to the atmosphere rather than exploding when it hits the ground (i.e., not much higher than 1kg/cm²), a high enough sectional density that it doesn't burn up entirely given whatever materials are on the front side of it, a shape that's aerodynamically stable in the supersonic regime, aerodynamics and structural integrity such that what doesn't ablate lands in one piece rather than exploding into a fireball, and good enough targeting that it lands on land in friendly territory rather than at the bottom of the ocean

i mean i'm not an expert in the area, but i think this is a well-understood set of problems. passive reentry vehicles have been used for decades for spy satellite film canisters, v-2 ballistic missiles, scud ballistic missiles, icbms, mirvs, and space capsules like those used in the vostok, apollo, and mercury programs. it gets easier in this case because you don't care if it breaks when it hits the ground, so you don't need parachutes or retrorockets; you just don't want it to vaporize

specifically, a hunk of mass at rest at the von kármán line of 100 km has 981 kilojoules per kilogram of gravitational potential energy with respect to the ground. one degree of temperature is roughly one kilojoule per kilogram, so that's roughly 981 degrees of heating if it falls to the ground from that height with no further air resistance—not enough to melt steel, nickel, gold, platinum, or even mafic rocks. and it's still 981 kilojules per kilogram whether it's a kilogram of platinum or a thousand tons of platinum. but it gets better! that heating is shared between the reentry vehicle and a somewhat larger mass of whatever it hits, roughly in inverse proportion to their stiffness. and of course there is atmospheric resistance, even without a parachute—quite a significant amount of it at the comparatively low sectional densities you need to lose most of your escape velocity from hitting the atmosphere. so, typically, when meteorites land, they aren't even hot. the arguments above explain why in most cases they can't be hot unless they hit so hard as to blow open a crater

980 kilojoules per kilogram is 1400 meters per second, about mach 4, so you really don't want it to hit you. but it won't even melt, and newton's penetration depth approximation assures you it won't penetrate very far into the ground, like, less than a meter

so basically you're worried about a nonproblem


Rare earth metals might be a good use case....say the stuff used in cytalitic converters etc


Rare earth metals are not actually rare.


Might make sense for Mars or a moon base too.


I'm not sure what substance you could mine on an asteroid that could possibly be economical.

The first obvious assumption is would have to be launched from space and return to space because the cost of getting a payload from Earth to LEO is a huge extra expense.

Then you have to consider the delta-V of getting to the asteroid, doing a rendezvous and getting back. If that's so significant that the Earth launch cost is trivial then the delta-V budget is so huge, it must make the endeavour even more uneconomical.

I believe humanity's future is in a Dyson Swarm. There are simply too many advantages. This is a deep topic. The question is how do you bootstrap that? Where do you get raw materials?

I don't think it's from asteroids. I very much suspect it's from a larger body and my money is on Mercury. Why? On pretty much any body in the Solar System you're living underground so Mercury is at no disadvantage here. It has no atmosphere. That's an advantage. Mars's super thin atmosphere is the worst of both worlds. Additionally, Mercury is metal rich and due to its proximity to the Sun, energy is abundant (ie solar power). Interestingly, it has a higher orbital speed than Earth (47km/s vs 30km/s). That's really interesting because it's free velocity to leave the Solar System.

Resources on EArth are so ridiculously cheap. You can mine iron ore for a few dollars a ton at scale. You can convert it into steel really cheaply too (again, at scale). Doing anything in space requires having truly stupendous amounts of cheap energy available.


Mercury sounds interesting. Requires a certain scale though (gravity is a bitch).

Considering just the initial mining and construction, bodies with low gravity and proximity to the earth feel like an efficient starting point, right? I always thought the moon would be a good place to bootstrap the first few thousand space habitats.

Your point about energy will probably be the biggest deal. Wondering how complicated it would be to ship a bunch of nuclear reactors to the moon. There seems to be quite a few companies working on small, "mass produced" reactors currently.


In terms of delta-v, the asteroids are much closer to us than mercury. A small one in the belt is like delta 1.5km/s from earth escape, versus 11km/s to mercury. Heck, the Mars moons are technically closer to us than 'our' moon. (Overview i.e deltavmap.github.io/)

And the sun is a gravity well. Mercuries higher orbital speed will not help you leave the solar system. In fact, it is the other way around.

Oh, and solar cells are already crazy good. With all the space you have out there, higher energy density on mercury will be very marginally important.


Send a piece of lead in orbit around the sun so it heats up but not melts, when it comes around heat some water to steam. Free power!


The internet is a messed-up place, because as much as I'm convinced this is a joke, I'm also certain somebody could write the same comment in all seriousness and think they are making a great discovery.

We can't even just laugh.


the idea is actually workable, it just isn't competitive with other ways of exploiting solar energy


It has some really serious drawbacks, like needing to repeatedly synchronize and desynchronize orbits. That makes it crazy complex even on the context of crazy futuristic space machinery.

That "isn't competitive" is quite an understatement. But yeah, technically it doesn't break any law of Physics.


Once all of your water is steam, how do you get it back into a liquid phase so that you can do it over again?

Or so that you can do other things, like drink it...


There are neutron stars that create chunks of gold and platinum larger than the size of earth itself.

Highly doubt such chunks are floating around our solar system but it's an amusing thought that one day hundreds of years from now we could nudge a (much) smaller chunk into orbit or park it in a Lagrange point and shave off pieces to return to earth.


> There are neutron stars that create chunks of gold and platinum larger than the size of earth itself.

Aren't neutron stars 12 miles in diameter on avg?


Neutron stars are the literal limit to how much matter can be collapsed before it turns into a black hole and yet still remain a star.

A neutron star 12-16 miles in diameter contains the mass over HALF-MILLION earths, it is very hard to fathom but yet they exist!

So popping out an earth-sized chunk of gold after collision with say another neutron star (kilonova) and ejecting matter to "normal" density is plausible.


re: delta V, the chaotic nature of orbits involving many bodies means that a very well-timed nudge ought to be sufficient to move certain asteroids quite a long distance for "free". So the problem becomes finding the right asteroid, and the right time, and the right nudge vector. More about computation than rocket fuel: the deeper into that chaotic system we can penetrate, the less we have to spend on influencing it.

You've also got to slow it down when it gets to where your smelters are. For that I'd propose we just let it smash into the moon and then mine it on the surface. We can alternate which sides we smash into in order to prevent the moon's orbit from changing significantly.

Of course you still need to provide the initial nudge, which ain't nothing, but it's a far cry from towing an asteroid or towing a smelter.


A medium-sized asteroid identified had something like $3T of titanium on it. Of course, that's gross value and you can’t clear your supply at that price. But even if it costs hundreds of billions to extract you should be able to net a profit.


Using the rocket equation, it is possible to compute the ratio between the $kg launch cost and $/kg material sell price that would make it economical.

Based on my calculations, with optimistic assumptions (including the asteroid being made solely of the desired material), you need 5 Falcon 9 launches and in-space assembly to bring back one ton of material, which would require selling the material for 350k$/kg for parity. But gold is only 80k$/kg, platinum is 30$/kg, etc.

Doesn't look feasible with current technology.


> Doesn't look feasible with current technology.

If you don't pay the demanded price before it arrives in orbit, it will be delivered a full speed on your lawn. Your entire city will be destroyed.


Can you share your calculations and assumptions that go into them?


What about with StarShip tha, whilst unproven, looks to be on path to the goal full reusability?


The title is far too generous. They've only launched a single spacecraft so far which failed due to communications issues. They're planning to launch a second spacecraft in Q4 this year which will fly by an asteroid and take pictures. They're planning a third spacecraft which they say will dock to an asteroid using magnets because it's "likely iron rich" and basically take measurements.

Nothing about actually mining resources and returning those materials to Earth. So they've gotten funding from investors? In the past, even dumber endeavours have gotten even more funding than this, it really doesn't mean anything.


"The docking mechanism is simple—since the asteroid is likely to be iron-rich, Vestri will use magnets to attach itself."

While that sounds simple, it does make it sound like the mining part just became much more difficult.

Thinking about some of the sci-fi regarding asteroid mining, I've always liked the idea of bringing the asteroid to park into an orbit around earth to make it easier/cheaper for multiple deliveries, but I've always wonder what kind of ownership claims that would imply. If I took the time and effort to park an asteroid in orbit, would I have sole ownership of it or would you be able to mine from it as well?


> I've always liked the idea of bringing the asteroid to park into an orbit around earth to make it easier/cheaper for multiple deliveries

I think you're dramatically underestimating the difficulty of doing this.

If you look at rockets, they're 90-95% propellant. Even relatively svelt upper stages like Centaur III (the upper stage from Atlas v) are more than 50% propellant. And that's for just taking payloads to LEO - for higher energy missions, the usable payload gets smaller, which means the percent of the upper stage that's propellant increases.

How difficult would it be to get an amount of propellant, say, 5 times the mass of the asteroid to the asteroid? You'd also have to get the engines and other structures to let you use the propellant in a productive way.

It's way easier to extract valuable parts from an astroid and move a lot less mass there and back.


Moving mass back with a free return trajectory is much easier than getting stuff out of Earths gravity well and up there. Escape velocity from an asteroid is low and if you yeet it with enough precision you can send it on a trajectory that will land it on Earth.

As for moving the asteroid you could use extremely high specific impulse ion thrusters, in situ propellant from the asteroid itself, or a solar sail. But you are right that simply firing the valuable stuff back to Earth is probably easier.


What about using the asteroid itself as fuel? Even if the asteroid is devoid of hydrocarbons that could be turned into fuel for conventional engines iron make a suitable (albeit inefficient) fuel for ion thrusters powered by solar panels.

Mass drivers and linear rails are also viable ways of bringing raw material into Earth's orbit from asteroids of a certain size.


This was my thought as well. Also for what it’s worth iron oxidation is slow but very exothermic.

So what you’d want is a LEO starting point/station. You launch a barge from there to snag an asteroid. You could use a mass driver using solar or nuclear and mass from a previously spent asteroid to get to the asteroid belt, then snag an asteroid and use its mass to get back. You strip the important parts of it, construct a capsule for what you mined, and nudge it so it falls someplace in say a shallow part of the ocean. Then recover from there.

Or hell why mine it up there? Simply nudge an asteroid on a collision course towards Earth to make sure it falls someplace “safe”. Sure most of it will burn up but not all. It’s free material after all.


Didn't the asteroid that destroyed the dinosaurs hit the ocean?


Sure. So size matters. If you drop a rock in the ocean it doesn’t darken the skies, does it?

Meteors fall onto Earth all the time. It is a matter of composition, trajectory, and mass, no?


> It is a matter of composition, trajectory, and mass, no?

We're talking very specifically about an asteroid made up of iron. Logic would follow that it would be on the more massive end of the scale. No? That's like the worst possible composition and the very type that worries the doomsday types.


Lead is much heavier than iron. A uranium asteroid is pretty bad too.

But that aside, we have plenty of iron right here on earth. There is zero reason to mine iron in space unless you need it in space. An asteroid of pure gold on the other hand…

But setting all that aside, you get to choose the size! And the trajectory! And the arrival point! Like if you toss a 100kg asteroid and get 1kg of gold out of it, no you won’t kill the planet. You get to choose all the variables.


Probably at very high speed (in excess of orbital velocity) and near head-on.

Ideally you’d put an asteroid in LEO, slow it below orbital velocity, and have it come down at a shallow angle so aero breaking removes most of the remaining velocity.


Not to mention the governance and liability implications of the plan. If a company mining something on Earth screws up really badly, they can ruin the environment for a hundred miles around. If a company mining an asteroid in LEO screws up really badly, the literal blast radius would wipe out a significant percentage of life on earth.


Why does it need to be parked in LEO? It could be kept in an orbit at the same distance as the Moon and it would still be relatively close compared to where it is now


Fair. I don't think we'd want that either, though, for the same reason. The moon is too close for comfort for smaller objects that we've proven we can move.


Ok, just park an ion drive on the asteroid and your descendant's descendants' descendants' get to mine it from LEO?


I don't think that moving the whole thing into our orbit would make much sense.

The biggest amount of delta-v is necessary to leave Earth's gravity well. Once you're there, going from and to asteroid is time-consuming but doesn't need that much delta-v, moving ore from the asteroid to Earth would cost some fuel, proportional to the mass.

So moving it into orbit would save time but require us to pay for the fuel all at once.

So why should someone do this, unless you need a permanent human presence on the asteroid?


> So why should someone do this, unless you need a permanent human presence on the asteroid?

Activity is only economically valuable if it is valued - i.e. by people.

Unless there's a population of people living in space, the ore or products derived from ore need to eventually make their way to Earth in order to be worth while.


I think we're all scared of the actual question posed or something as we've totally ignored it in everyone of these responses.

Nobody cares in sci-fi about whether something should/could be done. That's not the purview of the plot. It's also not the purview of the original comment.


I recently did an interview with them and found their perspective to be a little... flippant? A bunch of screw NASA, we sleep in the office, etc etc. I admit that I only spoke with one person in the company but it was enough that I realized it wasn't the work environment I wanted for myself. Regardless, I wish them all the best.


I'm no rocket scientist, but to me it makes sense to try and redirect asteroids to enter our atmosphere. The only thing I'd seek to "mine" on the asteroid is H2O, Hydrogen, or something that could be immediately converted to power/propulsion by the unit-itself.

I guess one risk would be introducing unknown biological or chemical nastiness. Another would be how precise we could be to target open ocean/desert/etc.


That’s insanely irresponsible. Even if everything goes perfectly you’re going to have volcano tier dust plumes altering the local climate and in the worst case you could kill millions of people by wiping out entire cities.


The cost of getting the asteroid to orbit, transportation (back and forth), and mining it would be too much. Even if we do this, keeping in mind that we can find some elements that we are aware of, I think it is way more important for humanity overall to execute this mission because there is always an upside that we can discover something that is much more valuable just like the company can sell the piece of just an asteroid as a souvenir.


Contracting their asteroid lander for various science missions is also a good opportunity. My bet is, that's where all the revenue in the next 10 years will come from.


I for one love the idea of space extraction, even if it is a pipe dream. Gathering minerals from dead space rocks seems better than from our planet.


Why not a mining operation in the Antarctic? Or the Sahara? Or in the Mariana Trench?

As all these options are cheaper and easier than asteroid mining, and as none of these bright-eyed ‘entrepreneurs’ are undertaking these tasks, I can only assume the things being ‘mined’ are gullible investors. (Not that I’m blaming them… what’s easier? Finding an asteroid with a precious metal, mining it and getting it back to earth at less the cost of mining it here? Or, finding a gullible venture capitalist who will cover your salary for a few years? Probable the latter…)


Platinum-group metals on earth: $965/oz

Water, volatiles and carbonaceous materials anywhere else in the solar system: priceless


Not really. You can't set up a "gas station" somewhere in the Solar system. It has to orbit. Anything in orbit goes many, many times faster than a bullet. Aligning yourself with such a fast moving object is doable, but costs a lot of fuel. Then detaching yourself from that orbit in order to go to your original destination burns a lot of fuel too. But let's say you get more fuel from that station than you burn. Who is going to replenish the station, and how? They need to burn a lot of fuel too, to go to an asteroid and back. It's not completely impossible, but it's quite unlikely.


Where did I say I’d waste volatiles moving things around?

(1) Build a solar sail factory on a CC asteroid and you can deliver sunshades to Earth-Sun L1 without wasting volatiles as reaction mass

(2) If you read this paper and really thought about it

https://arxiv.org/pdf/2011.07487

You’d realize that it strictly dominates all other space colonization schemes that have been proposed because it doesn’t waste volatiles for transportation. Certainly O’Neill’s ideas look infeasible in comparison (where do you get the nitrogen to fill those big airspaces? My plan for a baby Bernal sphere intended to be a luxury hotel in LEO still takes 15 starship loads of LN2 for the atmosphere)

Even Musk’s plan to colonize Mars is something that only makes sense to people who were born on a planet. If “grabby” aliens capable of interstellar travel and building such things here they might find the Earth a curiosity at best.


Solar sails are at this time quite useless for most purposes, and always will be if we can't build, fold, and deploy working sails of micrometer thickness, and/or build gigawatt-scale laser launch projectors.

Using ion thrusters it is already the case that we have access to power-generation-limited domain of specific impulse; Nobody thinks a mission at 30,000isp instead of 3,000isp is superior for interplanetary because of the sheer amount of waiting time and the extreme mass fraction of the solar panels. Solar sails, even moreso.

And one more dream to kill - large open volumes are probably never going to happen. This is implied by the mathematical engineering reality of the thin-walled pressure vessel, whose minimum mass scales directly with (volume * pressure) / tensile strength. Contrary to my naive expectations, there is no square cube ratio to the structure of a pressure vessel, so every cubic meter costs mass.


Solar sails and large open spaces face big challenges, but experiments like JAXA’s IKAROS, the LightSail missions, and NASA’s NanoSail-D2 have shown that solar sails can work in space.


Isn't that a bit like saying the solar car cross-country races show that solar-powered cars can work? In both cases the 'payload' and vehicles are stripped to the barest essentials.

Solar sails with any significant mass attached to them would either need to be impossibly large, and/or operate on timescales that make ion propulsion seem like a warp drive. And that's not counting the issue of stopping when you get to your destination, which will either require some insane laser/power source already at your destination, or propellant- in which case you're back to just using that in the first place.


You’re right. Solar sails need to be massive to move anything heavy, and they take a long time to build up speed. Stopping is another big hurdle. But they’re not supposed to replace everything. They’re useful when you can’t carry fuel, like on really long missions. They’re slow, but they work for what they’re designed to do: keep going without needing fuel.


Funny, a low performance solar sail is actually a high performance sunshade, you’d actually do better with a black sunshade than a highly reflective one.


Somebody pointed out to me that IKAROS didn’t last that long (neither did its namesake), so far that’s the best rebuttal to my L1 sunshade plan but I’d imagine a second generation product could do better. People so forget that space is a corrosive environment that will wreck many materials.

https://en.wikipedia.org/wiki/Long_Duration_Exposure_Facilit...


breaking news: asteroid mining company mismatch calculus and the rock hits a rural city in Texas


This gives me the same vibes as OceanGate's Titan, and Boeing's Starliner capsule.

Better these two as a role model than Theranos though.

Obviously the lack of any squishy humans that need to be part of the process makes it less of an issue when nothing comes of it.




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