Mining an Asteroid

I don't think the American West would have been populated so quickly if it weren't for the gold rush.

Here are some of the U.S. statistics for 1904:

* The average life expectancy in the U.S. was 47 years.
* Only 14 percent of the homes in the U.S. had a bathtub.
* Only 8 percent of the homes had a telephone.
* A three-minute call from Denver to New York City cost eleven dollars.
* There were only 8,000 cars in the U.S., and only 144 miles of paved roads.
* The maximum speed limit in most cities was 10 mph.
* Alabama, Mississippi, Iowa, and Tennessee were each more heavily populated than California. With a mere 1.4 million residents, California was only the 21st most populous state in the Union.
* The American flag had 45 stars. Arizona, Oklahoma, New Mexico, Hawaii, and Alaska hadn't been admitted to the Union.
* The population of Las Vegas, Nevada, was 30.

The fact that it's so, or that I said it?

Bringing an asteroid into orbit would probably start a war. Think about it. If you were say the leader of China and the US was bringing an asteroid into orbit would you believe their story that it was for mining?

Well which one would annoy you ?
Naturally it's the fact that the politicians are the most amazingly short sighted and parochial of people.
If it's not a fast buck or re-election they don't want to know.
The sooner we get rid of them the better.

Agreed absolutely.

Dude, if I were the leader of China I'd already have had one in orbit by now and be controlling the global metals and hydrocarbon markets. Not to mention being the absolute last word in microgravity manufacturing of critical computer components.

I assumed the the first asteroid we put in Earth orbit, would circle about 2/3 of the way to the moon, so $50,000 per pound may be optimistic. If people have to return to Earth from the mining site, And the metal is space available that can be used as ejection mass if an emergency occurs, then perhaps one dollar per pound.
Asteroids in the hundred ton to million ton range will likely be done at first, as they do little or no damage in most failure modes = they burn up in Earth's atmosphere. In this size range we can either mine them in orbit, or lower them gently to Earth's surface. The risk becomes significant in the final approach at reduced speed as it will likely land intact even if the wrong place. Neil

Hi heliotrope: If we hollow out a 1000 inch radius sphere at the mass center of the asteroid; we can install a bladder for a giant basketball. The inside surface area is A = 4 times 3.1316 times r squared =12,560,000 pounds pressure trying to expand the asteroid's shell. That is with one psi of 99% oxygen which might be enough for genetically altered humans. Opposing the expansion is the cohesion and adhesion of the shell material. There is essentually no gravity in small asteroids. As a precaution, we need to band the asteroid with many straps like we would a shipping create of inadequate strength. The humans will live in zero gravity = free fall.
1000 inches = 83 feet = 23 meters = really crowded with 10,000 humans. That big a hollow will be possible only in asteroids that have a mass of about a million tons or more. Million ton asteroids are rarely close to sphere shaped. so two habitats may be practical for some shapes. Neil

Niel you're not thinking big enough by a long way.
Or practical enough.

You don't need balloons, straps or anything else.
Half a kilometer of solid rock will insulate the interior and be air tight especially if you've lined the inside surface with concrete made from some of the mined material.
You rotate the asteroid about it's longest axis to provide pseudo gravity.
Everyone can live fine up there under the right g and conditions with no hassles.

The only problem is getting such a mass of atmosphere inside the damn thing and that can be taken care of with the next carbonaceous chondrite or passing comet that you hijack. They're full of volatiles. A cubic kilometer of ice has plenty of oxygen in it.

By the way, there is no way to lower anything from orbit to Earth's surface. It falls under gravity or you attach a rocket to it to slow it down.
I'll be buggered if I want the contract for the rocket.
If a space elevator was in place you could ship bits of it to the surface no worries but again, why would you want to ?
The only things you need to bring to Earth from space are the rare metals and compounds obtained from asteroids that will be processed in the existing factories on Earth to build more space vehicles which then build the same manufacturing facilities in orbit.
Once you've done that you don't have to bring anything down apart from the really shocking profits.

Oh, and there's no way you'd have an asteroid 2/3 of the way to the Moon either.
It's too far to go.
3 or 4 thousand kilometers is about right for starters.

all of thhe asteroids have slightly different compositions. Most are oxides or silicates of the metals. Usually nickel ferrous with some other trace metals. Id rather smelt and or/ calcine it up there by solar furnaces and then lower the metal down by
1 tooling it in space into a ball or cone or some friendly shape

2 then spraying /coating it with a layer of silicate sponge material to act as a heat barrier.

3Then fire that puppy down range and pick it up in an oceanic annealing bath. Then we could have it delivered as a billet right to the factories. All wed need is a big "catchers mitt" we can run metal analyses in space by icap and send the billets into a sustaining orbit and hold auctions for them.

A big catcher's mit ?
There's one called the Pacific Ocean

The ceramic foam will keep it afloat and protected as you say so you just tow it into the smelter and off you go.

Now, the only question I have is. Why are we mining asteroids? Im not sure of their average compositions but, most of the metal they contain, we are now throwing into landfills..
I have to go look up assay info on asteroids.. Ni and Fe arent making the economics work.Even if there is a 200% environmental surcharge on mine reclamation here on earth , payable to some international fund for healing mine scars.
I dont know whether there is enough rare earth or noble metal on an asteroid to make it pay back.
I know this is a feasibility question buit Im in an applied field. I can mine the gold from seawater, but cant make it pay unless gold is over 2500$ an oz.

I found a general composition as Iron /Nickel ?spinel. Spinel is an oxide usually listed as AB2O4 where the A is a divalent metal and B is a trivalent form, so its possible that many metals like Ti, Ta, Cr,Co may all be found. I didnt see any mention of Iridum or other rare or noble metals. Theres a ref to a 1993 issue of Discover Mag that has an apparent list of asteroid components..
Im sure Geochemica, Cosmochemica Acta has got more scholarly refs but I dont have the time to visit a University on-line library. Ill also bet a farthing that it will take a long time in que to get in and browse because its end o the term and everyones using the librarys on-line.(I usually go to U Penn/U Del/Bryn Mawr or Penn State for good on-line resources , but not today)

Yeh, I asked this question too, but the answer seems to be that we are not "mining" them for materials to be brought back to Earth, but instead, we are colonizing space, and using local resources to do our building.

If it's big enough to mine then it's big enough to cause a lot of damage.

Most shooting stars you see are the size of a grain of sand or a small pepple.

Something the size of a car would more than likely make it to ground and wipe out quite a few city blocks. Something the size of a house would wipe out a city.

There is no real safey margin with bringing them into orbit unless you think killing millions is a good business idea as long as you make enough money or think anything under a ELE is acceptable.

well tobruk, a counter to that is, whenever we bring the space shuttle back, its like bringing in a greyhound bus. Im sure , if un guided and in a suitable glide path , itd do lotsa damage on earth. The issue of accuracy on landing, IMHO, has never been in doubt. Youve gotta think we have the technology to machine a big hunk of metal into a gliding body.,strap an engine and a guidance system onto it, and bring it in without a care. BUT, Im still stuck on the "why" base
I dont think humans do anything in space with as cavelier an attitude as you portray. We do this because we must. Were just an incredibly curious species..The shuttle is even going back up and , i HEAR they are doing major redesign for safety to the vehicle.

Rosborne,Remember the "cost effectiveness " argument that Buzz Aldrin made about space travel.He said'100% of the money on the space program is spent on earth" I believe the only thing I see that an asteroid can provide in intergalactic prep, is if it were made an intergalactic near light speed platform itself. Im just playing the whatta we do game, and thinking in a slightly different box. However, I wonder whether we cannot reach aplanet like MArs and take its resources and crack its water for energy , and make it a jumping off point.
Still more Howevers , In reality, when we are going to the stars .It almost doesnt matter where we leave from, the destination distances are hewmongous in comparison.

I just looked this up in a BOOK.

1The solar system is about 10 light HOURS in diameter

2The closest star is 4.3 LIGHT YEARS (or 7200 times the distance from the sun to Pluto)

3 The nearest "earthlike planet" is 90 light years away (or 172000 times the distance from earth to Pluto)Its the star sytem HD70642 in the constellation "puppies" (my name is cuter if we have to go there)

4Big deal where we start, Im sure the intergalactic travelers would like to spend their last few days with their families cuz their families are all gonna be dead when the travelers return.

These vast distances make resources(to me anyway) not so critical from a source standpoint. In all cases, the provisioning is going to have to be sustainable . Its going to be Shelfords law of the minimum writ large.

Shuttles don't come in though at 100kms a second.

Plus not all countries have safety standards like the USA. For them the result is worth the cost......... cough old USSR and China cough

Tobruk, neither would a piece of metal that we processed in space. It would come back to the same jumping off spot from a deeper space processing "plant". We wouldnt just aim and shoot a chunk of metal the size of a Peterbilt toward the earth from the asteroid belt. Cmon, even the Russians wouldnt be that stupid.
Being worth the cost is exactly my point. I dont think the economics to produce a hunk of nickel or titanium is woth the cost of producing in space to anybody,when we have so much untapped ore and scrap metal here on earth. Hell, we have more titanium in beach sands than wed ever need......
But remember Rosborne wants this to be resources for manufacturing intergalactic ships and living quarters for travelers. Chances are this hunk of metal, would, under his scenario, never come to earth anyway.

Im just here for the free food.

It could come in that fast though if towing it into orbit was screwed up.

Known iron deposits on Earth are suppose to run out in a few decades. Lots of iron asteroids out there. We do need them here soonish.