Asteroid Mining Group
- Resources for the Future of Humanity -
Frequently Asked Questions:
- Isn’t this a very dangerous proposition?
- No. The asteroids we will target first will be on the small side (10 meters
or smaller), and of the “carbonaceous chondrite” class. These sorts of asteroids hit the Earth
every day, but disintegrate and burn up high in the atmosphere. The meteorites
that do survive passage to the surface generally come from much larger objects, likely 30
or more meters in diameter, and even those are blasted into smaller pieces
before they reach the ground. It takes a really large meteorite (50 or more
meters in diameter, depending upon its composition and structure) to actually
impact the Earth hard enough to make a crater.
- The Catch: Asteroids can be difficult to characterize remotely. A
carbonaceous chondrite outer surface could conceal chunks of metal. In fact,
the most interesting rocks, resource-wise, are extinct comets, which have developed a crust that both conceals and protects an inner core of volatile compounds (compounds that would evaporate if not for the outer crust), although those would be even more likely to evaporate before hitting the ground.
- The Solution: If you get very close to the asteroid itís possible to
determine the inner density distribution to a good level of accuracy, meaning
you can tell if a dirtball has metal chunks inside or not. Also, itís awkward to move one of them
accurately without determining its mass properties -- firing your control
thrusters and navigation thrusters will have unique effects depending on the
mass distribution of the asteroid payload.
- Isn’t it WAY too expensive to do this? Aren’t terrestrial mines a whole lot cheaper?
- For most products, yes. Currently, a combination of launch energy for the mining equipment and de-orbit energy for the products (the two energy levels are equivalent, if you want to land gracefully) puts the price out of bounds for products for Earth use.
- But that works both ways. It’s very expensive to bring stuff back; it’s also very expensive to send stuff there in the first place.
- So, if you want to *use* what you mine *in space*, if you can get it out of a rock that’s already in space, it is possible to do it more cheaply than launching that material from Earth.
- For example: Intelsat recently signed a legal document indicating to MDA that it would be interested in buying a total of 1000 kg of stationkeeping fuel, to be delivered to various satellites in Intelsat’s fleet. Their price tag? $270 million. That’s about half what it’s worth to Intelsat; currently, satellite lifetime is limited by stationkeeping fuel reserves, and if you can get 50 kg of fuel to a GEO (Geosynchronous Earth Orbit) comm satellite, that increases its lifespan by a year. $270 million for 20 years of design-life is a good deal for Intelsat, which would pay at least that much for a new satellite whose design life was within the 10-12 year range.
- The Catch: The most common fuel available on asteroids is water, which can be broken up via solar power into LH2 and LOX, which is used in such rockets as the Space Shuttle main engines and the Centaur booster. This type of fuel requires special cryogenic holding tanks, so for most satellites, stationkeeping is done with other fuels -- monomethyl hydrazine, etc. That is unfortunate from our point of view because
nitrogen (the backbone of hydrazine) is thought to be rare in asteroids.
- The Solution: There are a few different ways to proceed here. One, large enough asteroids (10,000s of tons) should still have adequate Nitrogen content to supply MMH needs. Or, a refuelable “Satellite servicing module” could be designed to use LH2/LOX and attach itself to existing satellites to provide stationkeeping services instead of relying on on-board fuel storage and thrusters. Or, you could use some of the carbon that’s on the carbonaceous chondrite asteroid in this example, and refine LOX / CH4 (methane) rocket fuel.
- OK, so stationkeeping is one potential customer. Is that enough to make a profit?
- $270 million is not enough to make a profit, but there are more customers out there. Intelsat flies about 10% of the GEO-orbit fleet. The US Government flies another significant percentage. And they could pay not just for station keeping, but for orbit-raising fuel as well. Right now we launch tons of fuel from the ground, stored in a kick-stage called a Centaur, which can carry as many as 20 tons of fuel at launch.
- The Catch: The Centaur’s fuel tanks get much of their structural integrity from the pressure of fuel inside. Launching them dry might not be safe.
- The Solution: If they could be redesigned to accept fuelling in LEO (Low Earth Orbit), the market would expand by several tons per commercial launch. Or, if other companies (say, SpaceX) are interested in designing a kick-stage of their own that could be fueled up with LH2/LOX on-orbit, that would provide a market as well.
- -How much fuel could you expect to find on one of these asteroids?
- The best-case Carbonaceous Chondrite is about 20% water by mass, with the water locked up in hydrated minerals. The average is probably closer to 10%. If you decided to use carbon compounds for fuel as well, that could increase the usable mass of one of these asteroids to as much as
- The Catch: With an asteroid the size that the Keck group is talking about retrieving, you could probably extract 50 tons of water. However, there’s only a market for about 10-15 tons of fuel per year in GEO.
- The Solution: Getting into the LEO-to-GEO orbit-raising fuel market
could make a NASA-like mission pay for itself.
- Aren’t asteroids hard to get to? Should we go to something closer first, like the Moon, instead?
- It takes less energy -- measured in change in velocity (or “delta-V”) -- to get from Earth to many of the asteroids we know about, than it takes to get to the Moon, land gently, and take off again. Also, in the case of the Moon, we can’t use highly efficient ion engines, and instead must use chemical engines, which can provide more thrust over a shorter period,
but require ten or more times as much fuel.
- Some asteroids are literally closer to us than the Moon as well. Knowledge of orbital mechanics, plus estimates of how many asteroids there are based on how many we’ve seen and by how many run into the Earth naturally every century, suggest that there is probably one asteroid in the 5-10m range in a temporary orbit around the Earth even as you read this.
- Would there EVER be a way to use this material on Earth? Or is this always going to be a sub-industry of our existing profitable space industry?
- Well, eventually mining will be productive enough to start returning large chunks of platinum-group metals to Earth. Simple blunt-body and ablative designs could be used to return materials, and small enough chunks could be dropped in remote enough areas to allay safety concerns.
- In the future, the elements to make airframes and thermal tiles are present in asteroids, which could replace blunt-body designs as in-space manufacturing improved. Eventually, these more sophisticated re-entry vehicles could “export” to Earth whatever goods we discover that can be more effectively manufactured in microgravity / vacuum / extreme cold than on Earth’s surface under a standard atmosphere
- Some academics and geologists believe that Earthís lithosphere has
insufficient supplies of metal to support Earthís current population at a Western standard of living. (http://www.science.org.au/nova/newscientist/027ns_005.htm) Other geologists and mining professionals disagree; but the point remains that eventually minerals (the Yale study specifically cites copper and platinum) are subject to demand that will drive their prices ever higher in the future.
- Another interesting possibility is instead of exporting goods manufactured
(or mined) in space to Earth, we could build space solar power stations out of
asteroid-derived materials and then export energy to Earth.
- -Don’t we need something like a Space Elevator to make this profitable?
- Not if we don’t move mass from Earth to orbit. Even masses processed in Lunar orbit could be returned to Earth for minimal energy -- like ballistic lunar capture (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090016184_2009015325.pdf) only backwards.
- Do we have the technology to do this, near term?
- Yes. See the following:
- Do we have the information-gathering capabilities?
- Yes, we have found 8000+ Near-Earth asteroids so far, the vast majority of them in the last 10-15 years (by LINEAR, or Catalina Sky Survey). We have even seen asteroids small enough that we can manipulate them safely with vehicles we can produce now.
- The Catch: Asteroids small enough to wrangle are very dim, and can only be detected when they’re close to Earth. In many cases a mission might not be able to reach them before
they drift away from Earth and we lose track of them.
- One Solution: JPL is already pursuing a strategy of small-body detection by going through Catalina Sky Survey data and looking for smaller blips that can be followed up by telescopes that aren’t on a programmatic search pattern like CSS.
- Another Solution: Planetary Resources plans to send up (comparatively) large numbers of orbiting observatories, which should be able to scan the sky for small asteroids out to maybe 10 lunar distances. This would be sufficient to detect asteroids (“mini-moons”) already captured into a temporary Earth orbit.
- -Why just use telescopes -- why not use radar?
- Telescopes work well because there’s an enormously energetic light source -- the sun -- supplying energy to reflect off of the asteroids in the solar system.
- We do actually use radar to explore asteroids. The trick is, you need a lot of power to send a radar ping to an asteroid and back again, so you need to know more or less where the asteroid is in the first place, and then ping it with a high-gain radar antenna. That gives you a whole lot of information -- the asteroid’s size and spin rate, and such.
- Do we have the rocket engines to get to them?
- Yes, ion engines have come into their own, and have been demonstrated on asteroid missions (like Dawn) already.
- The Catch: Ion engines will get you there efficiently, but they won’t get you there fast. It can take years to get into the outbound orbit, years to get to an asteroid, and years to get back. Once you start figuring in time-cost of money, that can mean you have to offer about a 5-to-1 return on investment to get investors interested.
- One Solution: Space is a fascinating enterprise, and it may be the case that investors can be found
who are more interested in investing in the future of humanity than in a
short-term return on their money.
- Another solution: With a large enough customer base for fuel, it could be done. With adequate support from NASA in the form of contracts to provide radiation shielding in Lunar orbit, it could be done. It would require efficient manufacturing of the retriever and adequately inexpensive development of a processing payload. If costs can be kept down, a 5-to-1 payoff is conceivable,
even in the relatively short term.
- Do we have the mining / processing payloads developed today?
- … Not that I can find. There are back-of-the-envelope calculations, there are known terrestrial processes, there are lunar miners (that depend on gravity to function), but if there are asteroid mining payload prototypes out there, I haven’t seen any.
- The Catch: Validating the performance of these payloads in sufficiently space-like conditions (e..g, a Thermal Vacuum (TVAC) chamber) could be very expensive, and worst-case could damage the chamber itself -- although Alta Space in Pisa currently plans to test 3D printing (in metal) in its TVAC chamber -- the results of that experiment could be relevant here.
- One Solution: Planetary Resources plan to use “swarms” of small and inexpensive satellites, which may end up being the least expensive way to test these payloads. Their failure-tolerant philosophy would come in handy here, too.
- Another Solution: This idea could be crowdsourced, either to interested parties (such as ISDC
attendees) or university students in either Aerospace or Mining Engineering programs.
- Why can we do this now, instead of, say 50 years ago when the idea was first floated by the likes of von Braun?
- Improvements in rocketry (especially ion engines) have only occurred in the last 10-15 years. This technology enables exhaust velocities that allow large delta-V’s (very energetic maneuvers) with small fractions of spacecraft mass devoted to fuel.
- Improvements in asteroid detection infrastructure (Catalina Sky Survey and such) have only occurred in the last 10-15 years. This could potentially have been pursued before, but the political backing has only materialized recently, as we realized just how common these bodies really are.
- As industry moves towards ever-larger spacecraft (40 kW range), the size of asteroid that we retrieve has only recently started to match the size of asteroid that we can detect from the ground.
- Improvements in astrodynamics in just the last 10 years include the discovery of the Interplanetary Transport Network (http://www.americanscientist.org/issues/issue.aspx?id=994&y=0&no=&content=true&page=3&css=print -- or if you’re comfortable with a bit of calculus, see http://www.cds.caltech.edu/~koon/book/KoLoMaRo_DMissionBk.pdf). If you’re patient, these approaches can let you travel from place to place in our solar system with very little energy.
- Isn’t all this new technology really, really expensive?
- Compared to the price of a car, sure. But compared to the price of a profitable commercial satellite (or compared to the fortune of a Silicon Valley Billionaire), not really. Flight hardware for JPL’s “Bus and bag” asteroid retrieval spacecraft closely resembles the largest commercial satellites being used today -- less than $500 Million. The closer the new spacecraft design is to legacy commercial spacecraft, the more that economies of scale can save in the manufacturing line.
- -Who’s going to pay for all this??
Do you use GPS? Do you use DirecTV? Do you use Sirius Satellite Radio? If so, you’ll probably help pay for it, and you probably won’t even notice. As companies pay for on-orbit fueling to reduce their launch costs, money goes from their customers (maybe including you) to their suppliers. In return, this technology will help improve the quality of those services, since with on-orbit fueling, satellites don’t have to devote launch mass to fuel. That means more transponders, more power, and generally more cost-effective payloads.
- -How would we survey and prospect these asteroids before we sink a lot of money into mining one of them?...
- Planetary Resources is starting its mining venture with inexpensive, mass-produced observation and prospecting satellites. If they’re looking for asteroids that are particularly rich in Platinum-Group Metals (PGMs), their prospecting approach is a good bet.
- Also, you’re just as interested in finding asteroids with favorable orbital elements -- so that they are easy to bring back into the Earth / Moon system. The easier they are to move, the bigger the load you can haul back -- or alternatively, the lighter (and cheaper) the spacecraft you can send out to fetch it.
- For some markets -- the radiation shielding market, for example -- what the asteroid is made of doesn’t even matter all that much, so prospecting doesn’t matter as much as determining how to get the asteroid to a spot where we could use it.
- Do we really have the money to spend on this, when there are so many other things to spend it on instead?
- The answer is, we ARE spending money on other things -- 300 times as much
money. NASAís budget is 0.3% of the federal budget. Space is not really all that expensive.
- Additional money is not being spent by “us” at all, but by people who’ve earned it in various high technology businesses... they have a right to spend it the way they wish. If asteroid mining turns out to be as big an opportunity as the likes of Dr. Diamandis says, this investment could make them even richer. The first trillion-dollar fortune will probably be made in Space.
- Space is cheap, and the rewards -- in terms of inspiration, science, technology, and engineering, not to mention natural resources -- are astronomical. Compared to how we spend our money now, and the fact that Space could pay off in the opening of a new frontier, this is the best investment we could possibly make.
- - Aren’t the Chinese in a better position to take advantage of this than we are?
- No. Their space program is young and ambitious, but our space infrastructure (particularly our for-profit industry, and even parts of our government endeavors) have experience and expertise the Chinese can only hope that they can match after another 20 years of effort.
- The Catch: That expertise -- especially the proud intellectual legacy of NASA -- is a use-it-or-lose-it proposition. The Apollo generation is retiring. The Space Shuttle generation is looking for other work. Even the astronaut corps is shrinking.
- The Solution: NASA needs to have the funding to get results. There are efforts that NASA is going undertake before our commercial industry, because their rewards are intangible -- the first man on Mars, the search for life -- and technologies that can’t turn a profit in a short enough term to get investors’ attention.
- - Shouldn’t we make asteroid mining a symbol of international cooperation instead of doing this on a private enterprise basis?
- We should not allow anything as uncertain as international relations to get
in the way, here. The majority of the rest of the world will be happy enough to
follow along with whoever leads the way.
- - Wouldn’t you have to have a moon base already to make asteroid mining worthwhile?
- No. While a moon base certainly would provide a very convenient market for asteroid-derived materials (there are many useful elements not found on the moon that are found on asteroids) it isn’t necessary to have anything there first.
- Asteroid mining enables everyone with dreams in space to achieve their dreams in a more affordable way,
whether those dreams are of settlements in orbit, on the Moon, on Mars, or near
- - Aren’t iron and nickel common enough on Earth that you couldn’t make money mining them in space?
- True enough. Iron is about $1.50 per kg. You’d have to return over 650 tonnes (650 thousand kg) of pure iron for each $1 million dollars you invested to break even. I’m not going to say it’s impossible, but I’m
also not going to say it’s likely.
- Fortunately, iron and nickel aren’t the only commodities on asteroids. Any iron and nickel we find on asteroids will probably be used in space.
- - Don’t we have other things to worry about, like debt and deficits?
- The only nations ever to have outgrown the level of debt that we have taken on are Britain (after Napoleon) and the United States (after WWII.) It took decades. It took massive expansion of industry and global trade. Asteroid mining is probably the only thing that would allow us a deep enough frontier and large enough economic expansion that we could outgrow our debts -- otherwise, we’re going to be stuck simply paying them off.
- - Wouldn’t it take huge amounts of energy and manpower to actually make this work?
- No, not really. It will take less than a tenth of NASA’s budget (if we go in the Public Funding direction). Companies of only a few hundred people (possibly as few as a few dozen) can actually build the sort of robotic spacecraft necessary for these endeavors, and their capitalization doesn’t need to be higher than hundreds of millions -- which is actually pretty low for a mining company.
- In terms of energy, 4 kW is enough to run a concrete-cutting tool here on Earth. Large commercial spacecraft run at 25 kW, and designs are in the works for 40 kW and even 400 kW spacecraft. Hundreds of kW may be necessary to heat some types of rock to extract its volatiles at a reasonable rate. No one’s done more than 75 kW (the International Space Station) but there aren’t any laws of physics standing in the way of power levels in the 100s of kW range -- that should be well within the competence of our power and thermal engineers to achieve.
- - Aren’t asteroids moving too fast to catch?
- They’re moving fast, so you run to catch up with them. Once you’ve matched their speed (think two cars cruising down a freeway, only without the wind whistling between them -- this is the vacuum of space, after all) it’s not impossible to reach out and grab onto them.
- The Catch: It’s a little tricky to grab them, still. Most of them are spinning, although many of them “spin” slower than the minute hand on a clock. Some of them are covered in “regolith” -- rock that has been pounded into gravel and powder by meteorite impacts -- so they’re tough to latch onto.
- The Solution: Many technical solutions are being debated even now. The simplest is to find a small asteroid and pop a bag over it. Harpoons, magnets, even pads with hundreds or thousands of tiny hooks on them, would also probably work.
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