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Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

daniel-suarez.com

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Re: Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

#61

Post by noir_lord »

evgen wrote: post #29
rlt wrote: post #25

Earlier quoted context omitted.

It’s probably just a coincidence, but I find it interesting that one of Elon Musk’s companies (Tesla) has a huge demand for nickel and another one of Elon Musk’s companies (SpaceX) won a contract with NASA to explore 16 Psyche, an asteroid essentially made of nickel, and is working on a completely reusable rocket...

The problems with this theory (and with asteroid mining in general) is that it is extremely unlikely that anything you mine in space will be economical to get back down. Most people forget that it costs almost as much delta-V to get down as it does to get up in the first place -- if something was not worth the cost to launch it into space it is unlikely to be worth landing. The problem with asteroid mining is that it…

> Most people forget that it costs almost as much delta-V to get down as it does to get up in the first place

Doesn't that depend on how you get it down.

Metal foam dropped from orbit into an ocean would float, you could have a retrieval vessel go pick it up.

Re: Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

#62

Post by evgen »

noir_lord wrote: post #61
evgen wrote: post #29

Earlier quoted context omitted.

The problems with this theory (and with asteroid mining in general) is that it is extremely unlikely that anything you mine in space will be economical to get back down. Most people forget that it costs almost as much delta-V to get down as it does to get up in the first place -- if something was not worth the cost to launch it into space it is unlikely to be worth landing. The problem with asteroid mining is that it…

> Most people forget that it costs almost as much delta-V to get down as it does to get up in the first place Doesn't that depend on how you get it down. Metal foam dropped from orbit into an ocean would float, you could have a retrieval vessel go pick it up.

Metal anything dropped from orbit at the speeds we are talking about would either burn up in the atmosphere or else hit the ocean surface and become lots of small chunks of something that is now sinking to the ocean floor. You need to shed a huge amount of delta-V just to get to the point where the landing site is described using any term other than 'impact crater.' Most of the mechanisms for dumping this energy tend to be a bit tricky to pull off and I am not sure, but there might be an upper limit after which ablation stops being a viable option.

Re: Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

#63

Post by adrian_b »

lopmotr wrote: post #35
vkou wrote: post #20

Earlier quoted context omitted.

The process chain necessary to turn rock into a single useful metal is colossal, and has been since antiquity. The effort required to set such a chain up, in space, for not one, but for dozens of metals (modern manufacturing requires many of them), as well as other chemicals (many of whom are inputs into other processes) would be astronomical. And then you would actually need to do something useful with that metal. I…

As I understand it, there iron and nickel asteroids that aren't chemically combined with other substances like ore is on Earth. So perhaps the only processing required would be melting and reforming it.

Iron and nickel are too abundant on Earth, so their transport from elsewhere cannot be profitable. They and other abundant elements can be mined only for building structures on those asteroids or in space.

The metals that are much more abundant on asteroids than on Earth will be dissolved in the Fe-Ni-Co metal in concentrations varying between 2 ppm for the most abundant (ruthenium) down to 0.05 ppm for the least abundant (rhenium).

While these very low concentrations are still thousands of times larger than the average concentrations on Earth, mining them on asteroids would still require processing thousands of tons of Fe-Ni-Co metal for a few kilograms of precious metals.

On asteroids that have never been melted, the processing could be easier, because most of the precious metals might be present in very small refractory grains dispersed between the grains of Fe-Ni-Co metal and silicate minerals and maybe a cheaper separation method could be found than for the case when they are in solution.

However, the same huge quantities of material need to be processed.

Right now, it is quite certain that this cannot be profitable.

Some time, in a more distant future, we can imagine a technology much more advanced than what we have now, which would enable sending some robots able to perform completely automatically the tasks of building from local materials some huge installations for energy collection, for mining and for extracting the desired elements, so that asteroid mining would require the transport in both directions, between Earth and the mined asteroid, of only very small quantities of materials and equipment.

Even if this is much beyond our current capabilities, it might become a necessity if we would exhaust the exploitable reserves for some of the least abundant elements, dispersing them in junk from which their extraction could become too costly.

On the other hand, there are numerous research projects now trying to replace the use of less abundant elements with the use of more abundant elements, in a lot of applications.

In most cases, it is likely that such substitution attempts are likely to succeed much earlier than the time when we would be able to mine those elements from outside the Earth.

Re: Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

#64

Post by qayxc »

WalterBright wrote: post #43
sacred_numbers wrote: post #21

Earlier quoted context omitted.

Mars will certainly be challenging to colonize, but it has some major advantages that I believe outweigh the disadvantages. First, water is pretty abundant almost everywhere on Mars. Second, carbon is abundant and nitrogen is abundant enough to make food and plastic production viable. Third, Mars has an atmosphere which is thick enough to provide some protection from radiation and meteorites but thin enough that cond…

What Mars lacks is a source of power. The solar incidence may be too weak to support much of anything. No fissile materials have yet been discovered there. The Moon has plenty of solar to harvest.

> What Mars lacks is a source of power. The solar incidence may be too weak to support much of anything.

Says who? The solar constant on Earth is about 1360 W/m².

Due to the atmosphere, only about 1025 W/m² actually get to the surface.

Mars, just from applying the inverse-square law has an average solar constant of about 589 W/m². Due to the lack of clouds and thin atmosphere, most of that reaches the surface.

So basically you get more than half the energy per unit area than on Earth. Coupled with batteries or power-to-gas and even wind power, I see no major power problem on Mars.

It's not as if there's a lack of usable land for solar arrays or big stacks of batteries on Mars...

Re: Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

#65

Post by Symmetry »

evgen wrote: post #62
noir_lord wrote: post #61

Earlier quoted context omitted.

> Most people forget that it costs almost as much delta-V to get down as it does to get up in the first place Doesn't that depend on how you get it down. Metal foam dropped from orbit into an ocean would float, you could have a retrieval vessel go pick it up.

Metal anything dropped from orbit at the speeds we are talking about would either burn up in the atmosphere or else hit the ocean surface and become lots of small chunks of something that is now sinking to the ocean floor. You need to shed a huge amount of delta-V just to get to the point where the landing site is described using any term other than 'impact crater.' Most of the mechanisms for dumping this energy tend…

Meteorites that arrive on the Earth from outer space are most certainly a thing that happens sometimes, that's wear all our existing Mars rocks come from for instance. Whether something survives reentry depends on a lot of factors including the size of the object, the angle of re-entry, its composition, etc.

Re: Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

#66

Post by Symmetry »

qayxc wrote: post #64
WalterBright wrote: post #43

Earlier quoted context omitted.

What Mars lacks is a source of power. The solar incidence may be too weak to support much of anything. No fissile materials have yet been discovered there. The Moon has plenty of solar to harvest.

> What Mars lacks is a source of power. The solar incidence may be too weak to support much of anything. Says who? The solar constant on Earth is about 1360 W/m². Due to the atmosphere, only about 1025 W/m² actually get to the surface. Mars, just from applying the inverse-square law has an average solar constant of about 589 W/m². Due to the lack of clouds and thin atmosphere, most of that reaches the surface. So bas…

The battery issue really cuts against most places on the Moon. Getting through 12 hours of night is a lot easier than getting through 2 weeks of night. There is the peak of eternal sunlight on the Moon's south pole where the sun marches around the horizon forever[1] but the lunar night is a big challenge everywhere else.

[1] And right next to an eternally shadowed crater we know has hydrogen, probably in water.

Re: Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

#68

Post by LargoLasskhyfv »

Symmetry wrote: post #52
snewman wrote: post #47

Earlier quoted context omitted.

Casey Handmer has a great blog taking hard analysis of what activities will be practical in space. He argues there is no real reason for asteroid mining to bring resources back to earth. So the challenge is to identify a large market for resources to be used in space. https://caseyhandmer.wordpress.com/2019/08/27/there-are-no-k...

So, the current price to bring something from space to Earth is for a capsule that keeps the material in a comfortable Earth-like atmosphere with minimal heating and g forces on the way down the way humans like it. If you instead have an object that doesn't need to breath and doesn't mind pulling 1000s of gs then things are much simpler, just take a reasonably sized sphere of your platinum ore, wrap it in some cheape…

Why not shaping it into some sort of lifting body, made out of honey comb like structures, and have that land into the ocean near the coast, to be towed to the next factory complex on land and disassamble the refined raw materials there? Combine with maybe inner compartments for standardized space containers for whatever else? This could be completely passive and autonomous, where the attached engine modules for deorbitng could detach and climb back up to some parking orbit or space dock before reentry happens. By choosing the right dimensions of that lifting body(surface to weight) you could avoid much of the reentry heat, down to about 400°C.

Re: Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

#69

Post by LargoLasskhyfv »

evgen wrote: post #29
rlt wrote: post #25

Earlier quoted context omitted.

It’s probably just a coincidence, but I find it interesting that one of Elon Musk’s companies (Tesla) has a huge demand for nickel and another one of Elon Musk’s companies (SpaceX) won a contract with NASA to explore 16 Psyche, an asteroid essentially made of nickel, and is working on a completely reusable rocket...

The problems with this theory (and with asteroid mining in general) is that it is extremely unlikely that anything you mine in space will be economical to get back down. Most people forget that it costs almost as much delta-V to get down as it does to get up in the first place -- if something was not worth the cost to launch it into space it is unlikely to be worth landing. The problem with asteroid mining is that it…

The thing is... we could outsource much of our current heavy- or other polluting industries 'up there', to finally remake the Planet of the Apes into the Garden of Eden, like it should be.

Wouldn't that be a nice goal?

Re: Delta-V: Designing the Asteroid Mining Ship 'Konstantin'

#70

Post by LargoLasskhyfv »

evgen wrote: post #62
noir_lord wrote: post #61

Earlier quoted context omitted.

> Most people forget that it costs almost as much delta-V to get down as it does to get up in the first place Doesn't that depend on how you get it down. Metal foam dropped from orbit into an ocean would float, you could have a retrieval vessel go pick it up.

Metal anything dropped from orbit at the speeds we are talking about would either burn up in the atmosphere or else hit the ocean surface and become lots of small chunks of something that is now sinking to the ocean floor. You need to shed a huge amount of delta-V just to get to the point where the landing site is described using any term other than 'impact crater.' Most of the mechanisms for dumping this energy tend…

When you have the ability to make it into foam in space, why not use that to make lifting bodies out of it, and let them glide down, instead of crashing like a stone?

Stop thinking in terms of projectiles. Just because the Space Shuttle came down like brick in a controlled crash doesn't mean there are no other ways to do this. Without the need for ablation, btw!

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