Aluminium Smelting in Space: What Would it Take?

Terraformer · 2016-11-15 05:38:05

I wonder how well a solar thermal rocket for surface launch would work? Or, perhaps more practically, focusing sunlight on a lightcraft. Coming down would be harder, but for shipping materials off-world it would be great. You could use water as the propellent, or ammonia, so it would be cheaper there.

elderflower · 2016-11-15 05:53:13

Why would you seek to win Aluminium on Mars? It will have large numbers of Nickel/Iron meteorites lying around and there are deposits of Iron Oxides.
For lightweight metals we should, perhaps, consider Titanium which is abundant on the Moon and probably on Mars also, although I'm not sure how it would be refined.

RobertDyck · 2016-11-15 08:20:32

elderflower wrote:

Titanium...not sure how it would be refined.

Lunar mare basalts contain a significant amount of ilmenite. High content = 18%, low = 5%, very low = 2%. Ilmenite is FeTiO3. I posted before how to smelt it, but too tired right now. I'll come back later.

Tom Kalbfus · 2016-11-15 08:38:16

Why is it important for metals to be light weight on Mars? They already weigh less. Also what is so political about Aluminum?

JoshNH4H · 2016-11-15 09:43:11

Terraformer,

The problem as always with solar thermal is the required collector area. At an efficiency of 65%, Vex of 900s, T/W of 8 N/kg, and solar flux of 1300 W/m^2, you need 43 square meters of mirrors per kilogram of initial mass. If your mirrors are on the ground you don't have to deal with that particular problem, but then pointing becomes an issue. I'm gonna do a post on the possibilities for nuclear thermal at some point and the results (which I'm sure will show that it's likewise too expensive) will be applicable to solar thermal in the sense that solar thermal is strictly worse than nuclear thermal.

Elderflower-

This has nothing to do with Mars. This has to do with the Moon and with creating viable economies in space. You cannot support space exploration by selling things to Mars because there are no people on Mars.

Tom-

Aluminium has the second largest market of any metal, after Iron/Steel. In principle, there's money to be made by producing it. If you notice, this subforum is called "Martian Politics and Economy". Economic and political issues are not really all that separable, but this falls much more on the economic side of things. Admittedly the Moon is not Mars but this thread is definitely on-topic for this subforum.

Terraformer · 2016-11-15 10:15:19

Okay, so maybe not mirrors. But given that Luna doesn't have an atmosphere or clouds to interfere with the beam, I think some kind of beamed power system (microwave?) is worth looking at for surface launch.

Tom Kalbfus · 2016-11-15 12:39:40

I think the Moon would be a great place for manufacturing, it might not be so cost effective to beam power from there to Earth, but industry could use the energy available on the Moon to manufacture stuff on the Moon for export, and getting them to Earth with a mass driver would be a simple task. The melting point of Lithium is 180.54 °C, so what are the chances of finding lithium on the Moon? The average temperature on the Moon is around 0 °C so lithium could be in the Moon's crust where the temperature extremes of the Moon's surface averages out. We could mine the stuff on the Moon. Lithium is used in lithium-ion batteries, we can mine the stuff on the Moon, encase it in titanium capsules so it survives atmospheric entry and then fling them to Earth on mass drivers, and by the way, no EPA to stop them! No environmental impact studies, and strip mining the Moon is perfectly okay!

JoshNH4H · 2016-11-15 13:51:15

Terraformer,

I'm definitely open to such a system. How would you go about it for large-scale launch?

Tom-

Lithium would likely be found in some mineral as an oxide, in combination with other metals. On Earth, it's mined from salt flats (Lithium salts are generally water soluble, so that they're concentrated in salty bodies of water; when these bodies of water evaporate they leave behind a bunch of salts including some lithium). Because the Moon has never had bodies of liquid water, such salt flats are unlikely to exist, although not impossible.

What is the abundance of Lithium on the Moon, and how does it compare to Earth? What is the market price of Lithium, and what is the annual volume? How would the market respond to a sudden and substantial increase in the amount of lithium available for use?

kbd512 · 2016-11-15 15:46:59

JoshNH4H wrote:

You appear to be implying that some kind of superconducting thruster will enable in-space transportation without the use of reaction mass. This might be viable in space (I like the M2P2 concept, or even better the "dusty" M2P2 concept, where the magnetic field contains particles that absorb some of the incident sunlight, thus acting as a solar sail), but in any gravity well you're going to need something more substantial to push back on.

I meant to imply that an appropriately shaped electromagnetic field can produce substantial thrust inside or outside of a gravity well. No plasma or solar sail is required and no incredibly energy dense power source is required. Efficient cryocoolers (preferably all-solid-state) and high temperature superconductors (existing superconducting materials, not as-yet undiscovered superconducting materials) are required. Neither of those two technologies are beyond our capabilities. The science involved violates no known laws of physics. This system is much simpler and less costly to actually operate than chemical or nuclear thermal rockets.

The Dr. Nassikas thruster, what I call S-thrusters, requires a $32K investment for further testing (I think $19K has already been provided and the superconducting tape is presently being wound by the manufacturer). Approximately 2/3 of that is the YBCO superconducting tape and 1/3 is the LN2 dewar to produce 66kg of force. The total mass of the thruster and dewar is 5kg. That's $525/kg of payload, or $1,050/kg for a thruster capable of 2G acceleration. The thruster has no move parts and can be re-used many times. The solid state cryocooler I proposed was intended to control thrust produced and provide immediate shutdown capability. It would weigh less than a LN2 dewar appropriately sized for a launch vehicle, even though it would add quite a bit of cost.

Scaled linearly and using existing superconductor and dewar technology, that translates into a $52M marginal production cost to construct a device capable of orbiting a 50t payload. There are no moving parts, no explosive cryogenic chemicals or infrastructure to produce and store those chemicals, no propellant storage tanks, and no heat shield required. The entire propulsion device itself would fit inside a 2 car garage. Obviously the VAB has to be taller or longer than a 2 car garage to mate the payload.

If a slightly more powerful and heavier version was constructed with retractable landing gear, it could be towed to the pad by a pickup truck. Launch pads located well away from infrastructure and self-destruct mechanisms are still required because it's still a potentially dangerous piece of aerospace hardware, but no sound suppression systems, flame trenches, or gigantic transporters and cranes are required.

The launch operation would vertically accelerate the payload at subsonic speeds to orbital altitude and then slowly accelerate to orbital velocity in a vacuum. Reentry would be accomplished in reverse, removing the requirement for expensive and delicate heat shields. Once the payload is in orbit, a less powerful and more compact version of the same technology would be used to maneuver in space.

JoshNH4H wrote:

We agree that chemical is too expensive. I'm about to write a post on the topic, but nuclear is probably also too costly.

The use of chemical propulsion for space mining and colonization is not feasible and probably never will be.

JoshNH4H wrote:

There are no asteroids made of pure platinum.

In 2015 an asteroid passed by Earth that was believed to contain more than 5 trillion dollars worth of Platinum. If we used propulsion technology that requires no propellant, do you think we could afford the equipment to mine it?

JoshNH4H · 2016-11-15 17:05:08

kbd512 wrote:

I meant to imply that an appropriately shaped electromagnetic field can produce substantial thrust inside or outside of a gravity well.

Ah, I see, you're trying to bring in thrusters that violate the laws of physics.

Leave me out of this nonsense please. You'll leave yourself out of it too, if you're smart.

kbd512 wrote:

In 2015 an asteroid passed by Earth that was believed to contain more than 5 trillion dollars worth of Platinum. If we used propulsion technology that requires no propellant, do you think we could afford the equipment to mine it?

I don't disagree that there are asteroids containing elevated levels of platinum relative to what you see on Earth. This is a consensus view among people who study such things with several different sources of evidence and physics to back it up.

What you said was:

kbd512 wrote:

...a robot could be sent to an asteroid made of pure or nearly pure platinum that you could cart off...

This is not something that exists.

At $34,000/kg, 5 trillion dollars of platinum is 150,000 tonnes of platinum. This is roughly 1,000 times as much as the entire worldwide production of Platinum. No reasonable person would expect the metal to hold its (extremely high) price under such circumstances, as the bulk of its price is due to scarcity, not difficulty of production.

Platinum is a very useful, rare metal so there is definitely money to be made by its extraction. However, it's easy to go overboard and produce so much that the price drops below sustainable levels. Platinum mining will likely come before Aluminium mining and serve an important function in the development of the in-space economy.

For example, let's say doubling production causes prices to fall by 1/3. The price of Platinum will be $22,000/kg. By producing 200 tonnes per year in space, miners can get an annual revenue of 4 billion dollars. This is comparable to the economy of Malawi or Eritrea.

However a comparable operation with aluminium yields an annual revenue of 60 billion dollars. This is comparable to the economy of Luxembourg, the Dominican Republic, or Uruguay.

There's a lot more value-added in manufacturing than in resource extraction, and I expect that to follow.

kbd512 · 2016-11-15 17:24:39

JoshNH4H wrote:

Ah, I see, you're trying to bring in thrusters that violate the laws of physics.
Leave me out of this nonsense please. You'll leave yourself out of it too, if you're smart.

No physical laws are violated. It's even less fantastic than the Q-thrusters. It's producing a force imbalance on one side of the electromagnetic field. The Q-thrusters work and that was supposed to be "impossible". Alternatively, some physicists are not nearly as smart as they think they are. What explanation for Q-thrusters do you think is the "right" explanation?

JoshNH4H wrote:

This is not something that exists.

If you never build something, it never exists.

JoshNH4H wrote:

At $34,000/kg, 5 trillion dollars of platinum is 150,000 tonnes of platinum. This is roughly 1,000 times as much as the entire worldwide production of Platinum. No reasonable person would expect the metal to hold its (extremely high) price under such circumstances, as the bulk of its price is due to scarcity, not difficulty of production.
Platinum is a very useful, rare metal so there is definitely money to be made by its extraction. However, it's easy to go overboard and produce so much that the price drops below sustainable levels. Platinum mining will likely come before Aluminium mining and serve an important function in the development of the in-space economy.
For example, let's say doubling production causes prices to fall by 1/3. The price of Platinum will be $22,000/kg. By producing 200 tonnes per year in space, miners can get an annual revenue of 4 billion dollars. This is comparable to the economy of Malawi or Eritrea.
However a comparable operation with aluminium yields an annual revenue of 60 billion dollars. This is comparable to the economy of Luxembourg, the Dominican Republic, or Uruguay.
There's a lot more value-added in manufacturing than in resource extraction, and I expect that to follow.

If you want the resources, you have to build the rocket and the robot. That was my only point.

JoshNH4H · 2016-11-15 17:43:07

If you never build something, it never exists

I meant the asteroid composed of platinum.

If you want the resources, you have to build the rocket and the robot. That was my only point.

Okay, sure.

Terraformer · 2016-11-15 17:43:19

It's producing a force imbalance on one side of the electromagnetic field.

...thus violating the conservation of momentum, part of the known laws of physics. Not that it can be ruled out - we could be wrong, as we have been in the past - but we have good reason to assign a low probability to to it working (though high enough to warrant funding it, perhaps).

kbd512 · 2016-11-15 18:06:05

Josh and Terraformer,

The S-thruster is a practical application of the Meissner Effect and nothing more exotic than that.

JoshNH4H · 2016-11-15 21:51:59

kbd512,

I'm not going to argue with you about this, but you're wrong and I encourage you to educate yourself.

Tom Kalbfus · 2016-11-16 07:14:23

JoshNH4H wrote:

Terraformer,
I'm definitely open to such a system. How would you go about it for large-scale launch?
Tom-
Lithium would likely be found in some mineral as an oxide, in combination with other metals. On Earth, it's mined from salt flats (Lithium salts are generally water soluble, so that they're concentrated in salty bodies of water; when these bodies of water evaporate they leave behind a bunch of salts including some lithium). Because the Moon has never had bodies of liquid water, such salt flats are unlikely to exist, although not impossible.
What is the abundance of Lithium on the Moon, and how does it compare to Earth? What is the market price of Lithium, and what is the annual volume? How would the market respond to a sudden and substantial increase in the amount of lithium available for use?

The transportation from the Moon to the Earth is a mass driver, the thing about it is that you can point a mass driver at the Earth and fire, depending on when you shoot your payload, it can arrive at any point on Earth, the shipping costs are minimal. No cargo ships are required. Also you can ship material mined elsewhere on the Moon quite easily enough, all you need is another mass driver, this one to fling material to the main mass driver which can send stuff to Earth. The smaller mass drivers just fling stuff on a suborbital arc towards the main mass driver which ships stuff to Earth. You can also have mass drivers at the Lunar poles, where water and other volatiles can be flung towards lunar bases elsewhere that need them. Vacuum is an excellent medium for transport, often a factor that is overlooked, people assume you need a rover or something like that.

So I envision a lunar mining operation with small mass drivers flinging material to the strategically placed large mass driver which sends stuff to Earth. Of course astronauts had better stay out of the drop zone when incoming material is on its way!

JoshNH4H · 2016-11-16 10:36:56

Hi Tom,

You say:

the shipping costs are minimal

How minimal is minimal? How does "minimal" compare to $0.05/kg? How much does it cost to build your mass driver? How big is it? How long does it last? What is the marginal cost? What is the maintenance schedule, and how much does it cost to maintain? When it breaks, is the failure catastrophic (payload hits mass driver at several km/s, which costs you money to rebuild and takes the mass driver out of service) or gentle (payload misses target)? Whatever numbers you pick for these questions, please provide justification. This is engineering, not science fiction.

You love to talk about how capitalism is so great (remember that time you suggested colonies should charge people for breathing?) but when it comes to on the ground cost-benefit analysis you're totally uninterested.

Tom Kalbfus · 2016-11-16 10:50:08

JoshNH4H wrote:

Hi Tom,
You say:
the shipping costs are minimal
How minimal is minimal? How does "minimal" compare to $0.05/kg? How much does it cost to build your mass driver? How big is it? How long does it last? What is the marginal cost? What is the maintenance schedule, and how much does it cost to maintain? When it breaks, is the failure catastrophic (payload hits mass driver at several km/s, which costs you money to rebuild and takes the mass driver out of service) or gentle (payload misses target)? Whatever numbers you pick for these questions, please provide justification. This is engineering, not science fiction.
You love to talk about how capitalism is so great (remember that time you suggested colonies should charge people for breathing?) but when it comes to on the ground cost-benefit analysis you're totally uninterested.

What does your intuition say it would cost to maintain a fleet of lunar trucks, traveling over the lunar surface, navigating around craters, climbing over ridges etc, compare that to flinging the same cargo on a suborbital arc towards the same location. if you wanted to place a bet, which could deliver the good more cheaply per ton? Also is there any better way to get stuff off the Moon's surface, a spaceship perhaps? f we are to deliver bulk goods to the Earth from the Moon, a mass driver is the best way to go. If were not delivering bulk good from the Moon, the base is not economically self-supporting.

kbd512 · 2016-11-16 19:31:17

JoshNH4H wrote:

kbd512,
I'm not going to argue with you about this, but you're wrong and I encourage you to educate yourself.

Although I agree that the theories and principles developed by Newton and Einstein are very good general explanations for a wide variety of physical phenomenon, that does not mean that everything they theorized is an immutable truth that's universally applicable. Einstein was a brilliant physicist, but even he had his limitations. IIRC, superconductivity was and is a major stumbling block which science has yet to adequately explain. I think it's a bit closed-minded to simply declare something impossible, absent any mathematical proof.

The EMDrive is either producing thrust or a good number of highly respected and accomplished scientists from China, Russia, US, and UK all can't seem to manage the setup of an experiment to measure thrust. As someone who actually believes in evidence rather than theory, I must concede that the latter explanation is possible. However, at some point the preponderance of evidence suggesting the former should be taken into account.

Rather than suggesting that I educate myself, which is a cop-out for an actual explanation as to why I'm wrong, would you ever consider sharing your knowledge so as to educate the rest of us and explain why so many names with so many years of experience behind them are all unable to execute a thrust test which produces a result in agreement with your supposition?

SpaceNut · 2016-11-16 21:28:35

Take the space drive propulsion to here Breakthrough In-Space Propulsion for Affordable Mars Missions

It would seem that we have a mineral pecking order for what is needed for earth and what is needed elsewhere plus what is needed for construction on the moon all of which would have different pricing for each use to export location. The same would be true for venus and mars as what they have could be bartered for what the other needs from the other.

JoshNH4H · 2016-11-17 22:39:26

Hi Tom,

What does your intuition say it would cost to maintain a fleet of lunar trucks, traveling over the lunar surface, navigating around craters, climbing over ridges etc, compare that to flinging the same cargo on a suborbital arc towards the same location. if you wanted to place a bet, which could deliver the good more cheaply per ton? Also is there any better way to get stuff off the Moon's surface, a spaceship perhaps? f we are to deliver bulk goods to the Earth from the Moon, a mass driver is the best way to go. If were not delivering bulk good from the Moon, the base is not economically self-supporting.

You're talking about mass drivers for surface transit? How exactly do you propose to catch what they're throwing?

Relative to such a system, I would say a network of roads created by bulldozing a strip of the lunar surface is absolutely cheaper. Depending on the value of labor you could even have the trucks that drive on these roads be self-driving, or you could build a guide out of bricks for the vehicles to follow.

For surface to space transit, mass drivers are definitely something I would consider. If you're sending stuff from the Moon, you're probably going to want to send it towards L4 or L5. The reason for this is that without a circularization burn, the payload will collide with the mass driver on the other end of its orbit which is not an acceptable risk. If it's going towards L4/L5, it's mostly out of the Moon's Hill Sphere (The not-actually-spherical region where the Moon's gravity is dominant) so that's not a worry even if you miss. Delta-V from Moon surface to L4/5 is 2.3 km/s. Assuming each shell weighs around 1 tonne, you'll probably be looking to fire them off multiple times per minute.

It's more expensive to build this system, but less expensive to use. Whether it's optimal or not really depends on volume.

SpaceNut · 2017-01-14 12:03:05

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#51 2016-11-15 05:38:05

Re: Aluminium Smelting in Space: What Would it Take?

#52 2016-11-15 05:53:13

Re: Aluminium Smelting in Space: What Would it Take?

#53 2016-11-15 08:20:32

Re: Aluminium Smelting in Space: What Would it Take?

#54 2016-11-15 08:38:16

Re: Aluminium Smelting in Space: What Would it Take?

#55 2016-11-15 09:43:11

Re: Aluminium Smelting in Space: What Would it Take?

#56 2016-11-15 10:15:19

Re: Aluminium Smelting in Space: What Would it Take?

#57 2016-11-15 12:39:40

Re: Aluminium Smelting in Space: What Would it Take?

#58 2016-11-15 13:51:15

Re: Aluminium Smelting in Space: What Would it Take?

#59 2016-11-15 15:46:59

Re: Aluminium Smelting in Space: What Would it Take?

#60 2016-11-15 17:05:08

Re: Aluminium Smelting in Space: What Would it Take?

#61 2016-11-15 17:24:39

Re: Aluminium Smelting in Space: What Would it Take?

#62 2016-11-15 17:43:07

Re: Aluminium Smelting in Space: What Would it Take?

#63 2016-11-15 17:43:19

Re: Aluminium Smelting in Space: What Would it Take?

#64 2016-11-15 18:06:05

Re: Aluminium Smelting in Space: What Would it Take?

#65 2016-11-15 21:51:59

Re: Aluminium Smelting in Space: What Would it Take?

#66 2016-11-16 07:14:23

Re: Aluminium Smelting in Space: What Would it Take?

#67 2016-11-16 10:36:56

Re: Aluminium Smelting in Space: What Would it Take?

#68 2016-11-16 10:50:08

Re: Aluminium Smelting in Space: What Would it Take?

#69 2016-11-16 19:31:17

Re: Aluminium Smelting in Space: What Would it Take?

#70 2016-11-16 21:28:35

Re: Aluminium Smelting in Space: What Would it Take?

#71 2016-11-17 22:39:26

Re: Aluminium Smelting in Space: What Would it Take?

#72 2017-01-14 12:03:05

Re: Aluminium Smelting in Space: What Would it Take?

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