Asteroid/Near Earth object mining

[glappkaeft]

Ion rockets use extreme exhaust velocity of tiny mass particles [like ions] to achieve thrust. A conventional rocket utilizes low exhaust velocity, high mass particles [like gas molecules] to achieve thrust.

Actually you have the masses of the exhaust gasses the wrong way around. Ion engines usually use rather heavy Xenon ions (atomic weight 131). Thermal rockets however get the highest exhaust velocity by having light molecules in the exhaust. Common exhaust gases are water, CO, CO₂, HF, excess H₂ and similar.

For any interested parties a recommend IGNITION! An Informal History of. Liquid Rocket Propellants by John D. Clark (available at http://library.sciencemadness.org/library/books/ignition.pdf )

 

[Chronos]

Actually you have the masses of the exhaust gasses the wrong way around. Ion engines usually use rather heavy Xenon ions (atomic weight 131). Thermal rockets however get the highest exhaust velocity by having light molecules in the exhaust. Common exhaust gases are water, CO, CO₂, HF, excess H₂ and similar.

For any interested parties a recommend IGNITION! An Informal History of. Liquid Rocket Propellants by John D. Clark (available at http://library.sciencemadness.org/library/books/ignition.pdf )

From the link I posted:
"...Ion rocket:
Force = little tiny mass x BIG ACCELERATION
Normal rocket:
Force = HUGE MASS x less acceleration..."

 

[glappkaeft]

Yes, that is correct, it about mass flow not the mass of the exhaust particles. The stuff from your previous post I quoted is not (in bold below).

Ion rockets use extreme exhaust velocity of tiny mass particles [like ions] to achieve thrust. A conventional rocket utilizes low exhaust velocity, high mass particles [like gas molecules] to achieve thrust.

 

[Chronos]

Agreed. Thrust is proportionate to the aggregate mass discharged, not the mass of individual particles discharged.Thrust of a chemical rocket is limited by propellent mass payload, whereas thrust of an ion rocket is limited by the energy payload available to discharge ions.

 

[1oldman2]

Being curious about the actual processing of the raw materials once the asteroid has been returned to Earth or lunar orbit, (I can imagine there will be considerable hand wringing over asteroids purposely brought into near Earth orbit), I did some searching and came up with a few links, should be good discussion material here.
First off there seems to be a lot of "Start up" interest in the field of Astro-mining. Deep Space Industries is partnering with Ames research of NASA affiliation, Their site https://deepspaceindustries.com/mining/ contains a lot of info on the companies plans and technology.

I found this one to be particularly interesting as it discusses aspects of Astro-mining I hadn't considered. http://www.permanent.com/asteroid-mining.html
This would likely fall in the R&D department. (Once again leaning heavily towards Mechanical Engineering)
http://info.heylpatterson.com/blog/heyl-patterson-develops-equipment-for-asteroid-mining
And then I thought I'd throw in another video (Which links to many other videos concerning the subject)

Also the video Greg has posted is an excellent take on this up and coming industry, highly recommended viewing.
I wouldn't be surprised to find E. Musk getting involved before long.

 

[1oldman2]

Another plan "in the works". http://www.space.com/33079-turning-asteroids-into-spaceships-made-in-space.html
Here is part of the article from Space.com, I'm particularly interested in the "seed craft" aspect.

"The Seed Craft would harvest material from the space rocks, then use this
feedstock to construct propulsion, navigation, energy-storage and other key
systems onsite with the aid of 3D printing and other technologies. (Made In
Space has considerable 3D-printing expertise; the company built the two 3D
printers that were installed aboard the International Space Station in the past
year and a half.)"

 

[mfb]

So far, we don't even have a system that can make complex things from rocks on Earth. In space it is more difficult...

 

[BiGyElLoWhAt]

I agree, but it's not that we don't have the technology. We could probably automate a foundry, computer chips are already manufactured via automated processes. It's not that we don't have the system, we just don't have it in place... because jobs.
https://en.wikipedia.org/wiki/Automated_mining

The mining industry is in the transition towards automation.

 

[BiGyElLoWhAt]

Another plan "in the works". http://www.space.com/33079-turning-asteroids-into-spaceships-made-in-space.html
Here is part of the article from Space.com, I'm particularly interested in the "seed craft" aspect.

"The Seed Craft would harvest material from the space rocks, then use this
feedstock to construct propulsion, navigation, energy-storage and other key
systems onsite with the aid of 3D printing and other technologies. (Made In
Space has considerable 3D-printing expertise; the company built the two 3D
printers that were installed aboard the International Space Station in the past
year and a half.)"

This is actually a really neat idea, and something that I hadn't thought of. It would probably be more efficient to do it this way, just a guess. It eliminates the need for setup/tear down of the actual mining equipment. Either way we went (on site/off site mining), we would still have to transport the material somewhere outside of the asteroid belt. Also, considering the asteroid belt, it would be much safer mining "near" the asteroid belt then actually on it. This method should reduces the amount of time spent in the asteroid belt by (and also the cost/value of) the equipment, which would alleviate some of the risk of spending weeks (?) or months (?) if not longer mining one asteroid.

One thing I don't quite understand is why they went for the navigation system they did. Wouldn't it make sense to just have 3 sensors on the asteroid and triangulate a signal from wherever it's going? Perhaps that would be too complicated in space with all the stars and aliens and things. Just spitballin'.

 

[mfb]

Automated mining is very far away from full automation.

It's not that we don't have the system, we just don't have it in place... because jobs.

Jobs are expensive, if you can automate them away it nearly always saves money. A system where you just have to switch it on, and something you can sell comes out - the dream of every company.

 

[BiGyElLoWhAt]

Jobs are expensive, if you can automate them away it nearly always saves money.

I 100% agree. However, people are afraid of it. I've had conversations with people who are. They want jobs, the more jobs the better. Not necessarily the companies, but society. I mean, we can totally automate Mcky D's, yet it hasn't happened (very much), because creating jobs makes the company look good. I don't think it would be hard to automate a foundry.
I used to work at a pattern shop, and 90% of what they did was CNC, which was probably 95% automated. Yea, you had someone standing there making sure it didn't crash, spraying the chips off the bits, swapping out tools, since it only had so many slots that it could hold a bit, but other than that, it was basically a computer and a computer program that shaved thousandths of an inch off of some hunk of metal.
I'm pretty sure we could then grab the part when it's done, and stick it in some sand. You could even use Styrofoam. Just add molten metal. It makes a mess, but I bet we could spray the machine down sort of like a car wash.

I might just be simplifying things, but in essences, these processes aren't complicated.

 

[Recycler]

All these technical approaches are really fascinating-not to spout off,but I have a comment about the theoretical Solar System's space "ecosystem."Every time humans get to a new place,they move things around,change things,and much later realize they have altered the environment.

 

[BiGyElLoWhAt]

All these technical approaches are really fascinating-not to spout off,but I have a comment about the theoretical Solar System's space "ecosystem."Every time humans get to a new place,they move things around,change things,and much later realize they have altered the environment.

Your name is a bit ironic, considering the post =P

I agree with your premise (I believe). However, in order to survive as a species, long term, we need to get off of the earth. That requires either a) finding a planet that is sustainable for us (and solar system), or b) altering the environment to make it so. a) is unlikely in my opinion, so then the question becomes: how much altering is OK? Maybe I'm just being naïve, but considering the fact that in a few billion years the sun is going to die, and no life will be possible in this solar system afterwards, and also the fact that it will take a long, looonnnggg time to find a new solar system that's young enough and with a planet in the inhabitable region of said start and also get there, I'm less than concerned about mining the asteroid belt to get us there. I highly doubt, even if we scrapped the entire earth, that we would have enough resources to get us all out of here.
(run-on sentence continues to run on, sorry)

 

[mfb]

It would be the first time the altered environment does not contain life (to our knowledge). I'm fine with altering a bunch of dead rocks, especially if the result is living rocks.

 

[Hoophy]

http://phys.org/news/2016-06-luxembourg-asteroid-law.html
Interesting...

 

[1oldman2]

http://phys.org/news/2016-06-luxembourg-asteroid-law.html
Interesting...

very... http://phys.org/news/2015-12-space-law-interplanetary-gold.html https://www.congress.gov/113/bills/hr5063/BILLS-113hr5063ih.pdf
http://www.unoosa.org/oosa/en/ourwork/spacelaw/treaties/introouterspacetreaty.html
http://www.slate.com/articles/healt...gets_to_profit_from_outer_space_platinum.html
http://www.upi.com/Science_News/201...y-violate-international-treaty/8751448634436/

 

[1oldman2]

From http://www.jpl.nasa.gov/news/news.php?feature=6537
"In effect, this small asteroid is caught in a game of leap frog with Earth that will last for hundreds of years." It says the asteroid poses no threat to Earth, I'm not so sure Earth doesn't pose a threat to the asteroid though.

 

[Borrah Campbell]

My opinion on the topic is that it is OK... just as long as we're talking about asteroids that don't pose a threat to Earth or her people : )

 

[mfb]

Disassembling or redirecting asteroids that pose a threat sounds like a good idea...

 

[D H]

Redirecting asteroids that pose a threat sounds like a good idea. Merely disassembling them may not be such a good idea.

 

[Hoophy]

Redirecting asteroids that pose a threat sounds like a good idea. Merely disassembling them may not be such a good idea.

The trick is finding them well enough in advance. :)

"Asteroids have us in our sight. The dinosaurs didn't have a space program, so they're not here to talk about this problem. We are, and we have the power to do something about it. I don't want to be the embarrassment of the galaxy, to have had the power to deflect an asteroid, and then not, and end up going extinct."
-Neil deGrasse Tyson

 

[1oldman2]

This ones a little dated but relevant, http://www2.esm.vt.edu/~sdross/papers/ross-asteroid-mining-2001.pdf
http://meteorites.wustl.edu/lunar/chemclass/ree.htm
http://meteorites.wustl.edu/goodstuff/ree-chon.htm
http://www.rsc.org/chemistryworld/2013/05/mining-ocean-seafloor-asteroids-space-minerals

 

[jack476]

OK I might as well throw this one in.
What is there on asteroids that is so specially valuable that it cannot be found or made on Earth without the extreme risk and cost.?

Good question, actually.

I think the main appeal of asteroid mining is that it allows for in situ extraction. Even a small asteroid could provide a large supply of minerals like iron and silicon, and if the asteroid happened to be in a convenient location, for instance if we were to capture a NEO, then harvesting those minerals from that asteroid would be much more cost-effective than launching tons of those materials into orbit after extraction on Earth.

 

[Borrah Campbell]

Good question, actually.

I think the main appeal of asteroid mining is that it allows for in situ extraction. Even a small asteroid could provide a large supply of minerals like iron and silicon, and if the asteroid happened to be in a convenient location, for instance if we were to capture a NEO, then harvesting those minerals from that asteroid would be much more cost-effective than launching tons of those materials into orbit after extraction on Earth.

I don't think it's iron & silicon we're after... Those are abundant "useless" minerals. What we want are the moon-sized diamonds floating around out there & the asteroids made of solid platinum... Well worth a trip to space & back and then some... just as long as it doesn't endanger the freaking Earth.

https://www.rt.com/news/310170-platinum-asteroid-2011-uw-158/
http://www.universetoday.com/9295/astronomers-find-a-huge-diamond-in-space/

 

[russ_watters]

Hey, hey, we have a little, baby asteroid-moon! Don't even have to capture it, all we have to do is spend a trillion dollars and invent a bunch of robotics technology to go mine it!
http://www.cnn.com/2016/06/16/us/nasa-asteroid-circles-earth/

 

[1oldman2]

Hey, hey, we have a little, baby asteroid-moon! Don't even have to capture it, all we have to do is spend a trillion dollars and invent a bunch of robotics technology to go mine it!
http://www.cnn.com/2016/06/16/us/nasa-asteroid-circles-earth/

I like JPL's write up on it, although CNN quoted heavily from it. See post #47, since the one mentioned never approaches closer than 38 times the distance from Earth to moon this might be a good test of the "break even point" for feasible distances to go for a space rock. All in all this will be an interesting industry to follow.

 

[anorlunda]

I think the main appeal of asteroid mining is that it allows for in situ extraction. Even a small asteroid could provide a large supply of minerals like iron and silicon, and if the asteroid happened to be in a convenient location, for instance if we were to capture a NEO, then harvesting those minerals from that asteroid would be much more cost-effective than launching tons of those materials into orbit after extraction on Earth.

Useful for what? Are you proposing that we make spacecraft factories in space? , Electronic chip foundries in space? Suppose you had 100 tons of iron ore in lunar orbit. How would you refine it? What would you do with the refined steel?

There is also the issue of radiation. As I understand it, propulsion mass, or materials are not the most limiting things to long-term human habitation in space, it is exposure to cosmic radiation.

I suppose that you could mine for water to make a 10 meter thick water filled radiation shield around each spacecraft , but what are your propulsion needs then?

IMO Projects like asteroid mining must await development of very capable autonomous robotic machines. The missions will be unmanned.

 

[lpetrich]

I looked for some numbers, and I found this:

Abundance in Meteorites for all the elements in the Periodic Table
Abundance in Earth's Crust for all the elements in the Periodic Table
Abundance in the Sun for all the elements in the Periodic Table

Source: ElementData—Wolfram language Documentation, working from ElementData Source Information—Wolfram language Documentation

For platinum:
The Sun: 9.*10^(-7)%
Meteorites: 9.8*10^(-5)%
The Earth's crust: 3.7×10^(-6)%
Apparently by weight; the Sun is listed as having 75% hydrogen and 23% helium.

Though meteorites contain about 30 times more platinum per unit mass than the Earth's crust does, it's still a tiny amount: 1 part per million. So to get 1 kg of platinum, one needs to mine 1000 tons of meteorite material. Checking on Platinum Price | Platinum Price Chart History | Price of Platinum Today | APMEX, I find that platinum's typical price as I write this to be around $31,000 / kg. So it will be hard to justify the expense of sending mining machines off of the Earth and to the asteroids.

 

[Hoophy]

I looked for some numbers, and I found this:

Abundance in Meteorites for all the elements in the Periodic Table
Abundance in Earth's Crust for all the elements in the Periodic Table
Abundance in the Sun for all the elements in the Periodic Table

Source: ElementData—Wolfram language Documentation, working from ElementData Source Information—Wolfram language Documentation

For platinum:
The Sun: 9.*10^(-7)%
Meteorites: 9.8*10^(-5)%
The Earth's crust: 3.7×10^(-6)%
Apparently by weight; the Sun is listed as having 75% hydrogen and 23% helium.

Though meteorites contain about 30 times more platinum per unit mass than the Earth's crust does, it's still a tiny amount: 1 part per million. So to get 1 kg of platinum, one needs to mine 1000 tons of meteorite material. Checking on Platinum Price | Platinum Price Chart History | Price of Platinum Today | APMEX, I find that platinum's typical price as I write this to be around $31,000 / kg. So it will be hard to justify the expense of sending mining machines off of the Earth and to the asteroids.

Is this an average of the platinum per unit of mass, of all asteroids? It is (was) my understanding that some asteroids are more abundant in some materials than others. Thanks. :)

 

[russ_watters]

Is this an average of the platinum per unit of mass, of all asteroids? It is (was) my understanding that some asteroids are more abundant in some materials than others. Thanks. :)

I would assume that is true...which means someone will also need to invent prospector robots and fund their activities.