This question has bugged me for years. Last week, a 30-meter asteroid created a 50 kiloton blast as it disintegrated in the atmosphere. A 300 meter asteroid (10 times the diameter, 1000 times the mass) would generate a 50 megaton explosion and probably big enough to survive entry into the atmosphere and make it to the ground. How do future asteroid miners deliver the mineral deposits to earth without a disaster occurring.
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Crossover_Maniac":23dmv4e3 said:
That is a good question actually. Although I don't think the whole Idea of asteroid mining is to mine asteroids on the earth, but to mine them out in space. Transporting the ore back to earth is where the problem lies. Technology has to be advance enough for development of Heavy lifters and gliders, or even space elevators.
Yep sending stuff like iron is just silly. Rare earths maybe and those could be sent down in a pod. Dont see why we cant just use the mats there in space though.
Having your entire space industry on earth i just a epic fail.
Having your entire space industry on earth i just a epic fail.
Crossover_Maniac":1dioheim said:
There should be a ceiling on incoming cargo, loads small enough they'd disintegrate harmlessly in the upper atmosphere in the event of an accident.
Exploiting the oberth effect makes it desirable to do the earth orbital insertion at a low altitude. Also the possibility of using aerobraking to shed velocity makes low altitude perigees more attractive. So I believe even cargo bound for the lagrange points might have an atmosphere grazing perigee on the way to their destination.
Most of the common earth materials mined from asteroids would be used in space, but the rare-earth and other valuable materials would be shipped back. I have 2 options that i like, both include containerization. Option one would be to have a robust and cheap spaceplane like an advanced form of the Skylon. The plane would haul up a large standardized cargo container with an ion (or other) engine, once in LEO the space plane would let go of the container which will fly to the destination asteroid. The container could also haul equipment and materials needed at the automated mining site. On the same flight the vehicle would pick up an incoming cargo container filled with valuable materials. After which it deorbits and automatically flies to its spaceport. The flights would only cost a couple thousand dollers each with a huge return.
Second option includes building large containers at the mining site with heat shields and sending them on a guided collision course with a terrestial desert. The containers would be guided to specific collection points in the deserts and the container material itself recycled for something else. Note: the containers would have paracutes of course, however since it it not manned and the container will not be reused in this option a highter velocity could be allowed. As long as it dosent vaporize and casue an impact crater.
Mining facilities could also send containers to other destinations in the solar system, such as other roids, Mars, Venus, Luna, orbital constructon yards and space stations.
Second option includes building large containers at the mining site with heat shields and sending them on a guided collision course with a terrestial desert. The containers would be guided to specific collection points in the deserts and the container material itself recycled for something else. Note: the containers would have paracutes of course, however since it it not manned and the container will not be reused in this option a highter velocity could be allowed. As long as it dosent vaporize and casue an impact crater.
Mining facilities could also send containers to other destinations in the solar system, such as other roids, Mars, Venus, Luna, orbital constructon yards and space stations.
SpaceXFanMobius57":61o1s8ig said:
Given expense of space transportation, rare earth or any materials couldn't be profitably mined. The asteroid could be pure crack cocaine and it still wouldn't be profitable.
In the near term, the most valuable asteroidal resource will likely be water and other hydrogen compounds. If propellent can be brought back to earth orbit with relatively little delta V, this would make it less expensive to reach our inner solar system.
The key word is "would", I am not using todays expenses, but tomorrows. The cost of lifting off the ground and returning will continue to go down to the point where at most it will be a few thousand per flight to LEO. This can be achived by better technology and business management. The return would be much greater than the expense to lift the container back up. The expense is in getting off the ground, once you are in space it is much easier and cheaper. Cheap and easy ways to get into LEO opens up the entire solar system to us.
SpaceXFanMobius57":3ifgwq5w said:
Why do you think so?
SpaceXFanMobius57":3ifgwq5w said:
If rockets were mass produced, as we do computers or cars, they would be far cheaper. Development costs would be amortized over many units.
However present flight rates don't justify mass production. Perhaps future flight rates will, but this isn't a given.
Further, high delta V budgets mandate multi-stage expendable rockets. Even if 747s were mass produced, plane tickets would be prohibitively expensive if half or all of the jet were thrown away each trip.
We use gravity from other planets to get our robots into their target orbits with many missions. The same technique could be applied to an asteroid. Aerobraking would be the final step to achieve Earth orbit. Much of the material could be used in space. Only refined metals or uncut diamonds would be sent down to the surface. With small enough comets, and depending on the purity of the comet, a direct hit on a lake would create a reservoir.
The assumption is that we will ever have a craft and launcher that can achieve reaching into deep space. We will need a new NASA or some other organization with vision to achieve that.
The assumption is that we will ever have a craft and launcher that can achieve reaching into deep space. We will need a new NASA or some other organization with vision to achieve that.
There is no need for bringing asteroid materials down here. We have plenty for our needs, besides bringing anything down here would significantly disrupt world market potentially resulting is some irreversible changes.
On the other hand, there is never enough materials up there. Just build refining facilities in orbit (geostationary or higher, higher the better) and make whatever you need to build a station, base or a ship.
Bringing down significant amounts of materials will, IMO, never be feasible. No parachute can withstand reentry.
On the other hand, there is never enough materials up there. Just build refining facilities in orbit (geostationary or higher, higher the better) and make whatever you need to build a station, base or a ship.
Bringing down significant amounts of materials will, IMO, never be feasible. No parachute can withstand reentry.
This topic has been argued to death on several boards. Mostly by people who haven’t though the entire thing through.
That won’t even fuel an airliner across the country. It doesn’t matter what kind your rocket uses. Do you really think the fuel needed will get cheaper?
Name one mineral we are in danger of running out of anytime in the next 100 years. Then run the numbers for how much it would realistically cost you to bring down 10 tons worth. That’s about how much a shuttle could handle.
Consider this.. We have been shooting metal up since the 1920’s. That’s about 90 years. Has it ever gotten cheaper?
Also pretend you have built a single stage to orbit space plane. The current cost per pound to orbit is about $10,000. Are you going to sell space for $10 per pound or $5000? The cost to orbit will never get dirt cheap. Pun intended.
That won’t even fuel an airliner across the country. It doesn’t matter what kind your rocket uses. Do you really think the fuel needed will get cheaper?
Name one mineral we are in danger of running out of anytime in the next 100 years. Then run the numbers for how much it would realistically cost you to bring down 10 tons worth. That’s about how much a shuttle could handle.
Consider this.. We have been shooting metal up since the 1920’s. That’s about 90 years. Has it ever gotten cheaper?
Also pretend you have built a single stage to orbit space plane. The current cost per pound to orbit is about $10,000. Are you going to sell space for $10 per pound or $5000? The cost to orbit will never get dirt cheap. Pun intended.
Crossover_Maniac,
The concept of asteroid mining is based on the premise that we will have the industrial capacity off-planet to utilize the materials we harvest from the asteroids. So dropping payloads of raw materials into the atmosphere is not very likely. What will be coming down will be using the atmosphere to slow down, and parachutes to lower the landing speed to acceptable levels. Most likely, what will be coming down will be processed metals, already cast into parts ready for assembly.
HopDavid,
Have you ever considered what impact carbon costs will have on industrial processing and mineral extraction here on Earth? It is quite likely that we are not going to be able to mine ore, smelt it down, and cast it here much longer, which will make any competing source cheaper than what we can produce here. Costs are subject to supply and demand. It used to be that hardwoods for furniture construction were readily available. Try finding large, clear pieces of hardwood today. Or consider crude oil: 75 years ago, most wells were less than 1000 feet deep. Today, we are drilling in thousands of feet of water, and going over a mile beneath the sea floor to reach oil deposits. A new field off of the coast of Brazil is being explored for exploitation, which will require drilling in 10,000 feet of water, and going nearly 3 miles beneath the ocean floor, through a layer of salt several thousand feet thick. We will never run out of crude oil, but we will probably not be able to use it for something as mundane as fuel after a while.
Environmental costs have only begun to be a factor in our technologically based culture, but they are threatening to increase at a rapid rate. We may soon face a choice of killing ourselves to maintain our technology, or moving it off planet.
The concept of asteroid mining is based on the premise that we will have the industrial capacity off-planet to utilize the materials we harvest from the asteroids. So dropping payloads of raw materials into the atmosphere is not very likely. What will be coming down will be using the atmosphere to slow down, and parachutes to lower the landing speed to acceptable levels. Most likely, what will be coming down will be processed metals, already cast into parts ready for assembly.
HopDavid,
Have you ever considered what impact carbon costs will have on industrial processing and mineral extraction here on Earth? It is quite likely that we are not going to be able to mine ore, smelt it down, and cast it here much longer, which will make any competing source cheaper than what we can produce here. Costs are subject to supply and demand. It used to be that hardwoods for furniture construction were readily available. Try finding large, clear pieces of hardwood today. Or consider crude oil: 75 years ago, most wells were less than 1000 feet deep. Today, we are drilling in thousands of feet of water, and going over a mile beneath the sea floor to reach oil deposits. A new field off of the coast of Brazil is being explored for exploitation, which will require drilling in 10,000 feet of water, and going nearly 3 miles beneath the ocean floor, through a layer of salt several thousand feet thick. We will never run out of crude oil, but we will probably not be able to use it for something as mundane as fuel after a while.
Environmental costs have only begun to be a factor in our technologically based culture, but they are threatening to increase at a rapid rate. We may soon face a choice of killing ourselves to maintain our technology, or moving it off planet.
halman":2fp5vyt5 said:
As rich deposits are exhausted and human population (and therefore demand) goes up, I do expect commodities to increase in price.
And I believe space access can become much cheaper. A small rocket architecture could enable high flight rates which might justify mass production. I don't see mass production of Ares Vs.
Presently high delta V budgets mandate multi stage mega rockets for getting people to Mars, asteroids, etc. But a way to circumvent the exponent in the rocket equation is multiple sources of propellent and propellent depots at various locations. It will never be possible to send a single stage reusable rocket from earth's surface to Mars and back. However a small single stage reusable craft could move between depots at LEO, EMLI, Phobos, and Deimos. Max delta V budget for such a craft would be around 4 km/sec. And if it never had to endure re-entry that further reduces mass requirements, failure modes and engineering difficulty.
A reusable lander/ascent vehicle between Mars and Phobos is perhaps doable. A reusable tanker to haul Lunar oxygen from the moon and EML1 is perhaps doable. Or, down the road, a mag rail could send lunar oxygen to EML1.
Developing Luna, Phobos and Deimos as propellent sources would take a greater initial investment than Mars (or asteroid) direct schemes, but it would enable transportation with smaller, reusable rockets. Smaller, reusable rockets are a sustainable architecture that could take us beyond flags and footprints.
A lot of people seem to have the notion that if only the incompetent, greedy, and evil NASA would get out of the way, private enterprise could skip going to the moon and starting building Martian colonies as well as cities in the main belt. Regardless whether a program is being conducted by SpaceX or NASA, if the vehicle is a disposable mega rocket with a low flight rate, it won't be sustainable and venture capitalists would never see a return on their investment.
Dropping a fully fueled ship from EML1 for a low altitude perigee burn would also be very helpful to send ships to asteroids (to guide this back to being on topic). Many asteroids are thought to be extinct comets that conceal volatile ice cores beneath an insulating mantle. These too are possible propellent sources.
In the near term I believe water rich asteroids will be the most valuable. With multiple propellent sources, returning asteroidal metal and other commodities to near earth space might become profitable.
At present, the costs and technical difficulty in moving into orbit or return to the earth are high. Until some form of quantum leap in rocket technology or some kind of space elevator comes along, it just doesn't make business sense.
Doesn't anyone else have serious reservations about the concept of taking large lumps of rock in deep space and directing towards a collision course with the earth? geez, they make movies about this kind of stuff. I am more than sceptical that this operation can never be accepted by most people.
Now, let's talk about the military and "national security", and this applies to any nation. Let's assume that some Chinese miners have directed a huge asteroid towards earth. Trust me, the military would crap their pants. I doubt any nation would endorse this scheme because it places national security at risk.
Doesn't anyone else have serious reservations about the concept of taking large lumps of rock in deep space and directing towards a collision course with the earth? geez, they make movies about this kind of stuff. I am more than sceptical that this operation can never be accepted by most people.
Now, let's talk about the military and "national security", and this applies to any nation. Let's assume that some Chinese miners have directed a huge asteroid towards earth. Trust me, the military would crap their pants. I doubt any nation would endorse this scheme because it places national security at risk.
has anyone considered the possibility of mining Luna for minerals? there must be asteroid remnants in those craters. any opinions?
hoodoomeatbucket":1m7n1ig7 said:
They're talking about mining the moon for water. No need to carry water, propellant, or oxygen there if there is water.
yes, of course i know about the potential of water on the moon. you can't do much without that. i meant the type of mineral mining being discussed in this thread. metals, the sort of things we might want from asteroids, there being so many asteroid impacts on luna's surface. but thanks anyway.Crossover_Maniac":3ptaq0d4 said:
Huge momentum exchange tethers = bolo are a far future possibility, but space elevators seem more likely since both need a material about 20 times stronger than kevlar to get per kilogram shipping costs below typical international air freight cost.
We send a 10,000 ton asteroid toward Earth, the bolo catches it at an altitude of perhaps 100 kilometers, slowing the asteroid by one kilometer per second and speeding the bolo by 5 kilometers per second, which means the bolo can next launch several 1000 ton space craft to the Oort cloud, before it needs to be sped up again. Perhaps a fair trade, even if the value of the asteroid averages zero on Earth's surface. If the catch fails, the 10,000 ton asteroid burns up in the atmosphere, producing little or no liability for the bolo owners. The bolo is 1000 kilometers long, and can catch and throw with both ends, so throughput is high with a tip throwing speeds of 15 kilometers per second. Several other bolos can catch the same asteroid before it lands on Earth's surface, each slowing it about one kilometer per second. Is my arithmetic and thinking correct, assuming we have customers for 100 craft per week going to the Oort cloud and/or outer solar system? Neil
We send a 10,000 ton asteroid toward Earth, the bolo catches it at an altitude of perhaps 100 kilometers, slowing the asteroid by one kilometer per second and speeding the bolo by 5 kilometers per second, which means the bolo can next launch several 1000 ton space craft to the Oort cloud, before it needs to be sped up again. Perhaps a fair trade, even if the value of the asteroid averages zero on Earth's surface. If the catch fails, the 10,000 ton asteroid burns up in the atmosphere, producing little or no liability for the bolo owners. The bolo is 1000 kilometers long, and can catch and throw with both ends, so throughput is high with a tip throwing speeds of 15 kilometers per second. Several other bolos can catch the same asteroid before it lands on Earth's surface, each slowing it about one kilometer per second. Is my arithmetic and thinking correct, assuming we have customers for 100 craft per week going to the Oort cloud and/or outer solar system? Neil
hoodoomeatbucket":2p4mug2x said:
There probably are reminants but there mixed in with martain regolith which makes earth sand look like boulders in comparison. Very very small sticky and tough to remove. Also they are in a gravity well.
The moon has a place for mining but asteroids contain many of the materials a space based economy needs to get off the ground and that earth would need to supplament rare materials found here that would otherwise cause a road block to scientific, technological, and industrial advancment.
One of the things about Zero-g is the ability to produce goods there not possible or ruinously expensive here.
Many commerical nitches are available in orbit and in space it just needs a boost to help get there. So like the railroads Nasa is essentuall to help bring that.
Oh and another thing about asteroids they can be used as there own bases. There is no need to send a ship out everytime.
Also we arent talking bus size chunks of lithium, platinum and other rare materials to earth. These are just needed in small amounts. Think something like a bare bones pod sent down say 2 to 3 times a month. The amount of ore/materials made here on earth is sometimes only a few dozen tons a year yet our economies would not be hear without them.
neilsox":2gptts63 said:
10 000 tons decelerated at 1/kms^2?
You would need to apply 1 billion Newtons of force to accomplish it.
What would hold your bolo in its position?
hoodoomeatbucket":18fyq74b said:
Water will be the most valuable space commodity. Sources of propellent at various locations break one long journey into smaller legs. Simpler, reusable vehicles become possible.
When space transportation costs drop, only then will mining platinum etc. become viable.
Recent Chandrayaan 1 and LRO data suggest thick (2 meters or more) ice sheets at the lunar poles.
There's abundant aluminum and silica as well as oxygen in the regolith. This may become valuable ISRU resources.
And there could be rich mineral depots at sites of meteorite impacts.
I think this is a little naive. Estimates of a 25m diameter asteroid (relatively small) can produce up a 700 meter crater for iron, or airblast of fraqments that could cause a lot of other damage (think Tanguska) if rock.neilsox":qsk4ct36 said:
On breakaway, you would have no idea where it would hit, and because of low relative velocity compared to a normal asteroid re-entry, would probably make it all the way down.
Here is a handy little calculator for impact effects:
http://impact.ese.ic.ac.uk/ImpactEffects/
Play with it yourself a bit, if you like.
It would be interesting to drill into the mascons on the moon, rumored to be iron...HopDavid":2n3vpnzl said:
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