Kind of funny - with all the news about Planetary Resources Inc and asteroid mining, here's some notes I made back in 2006 on the topic to talk with some of my colleagues on the subject.

1. Asteroid Mining
Opportunities
Notes
1

2. “Early evidence suggests that there are
trillions of dollars' worth of minerals and
metals buried in asteroids that come close
to the Earth. Asteroids are so close that
many scientists think an asteroid mining
mission is easily feasible.”

3. Value
3

4. 
Value of ANYMaterials per kg.
Launch cost
of material from earth: $10,000
 “Note that the asteroidal materials we are talking about are, simply, water,
nickel-iron metal, hydrocarbons, and silicate rock. Purified, and made
available in low earth orbit, they will be worth something like $500,000 per ton,
by virtue of having avoided terrestrial gravity's "launch cost levy."
 “These values are up there with optical glass, doped semiconductors, specialty
isotopes for research or medicine, diamonds, some pharmaceuticals, illicit
drugs. On the mining scene, the only metal which has ever been so valuable
was radium, which in the 1920's reached the fabulous value of $200,000 per
gram!
 Platinum Group Metals (which are present in metallic and silicate asteroids, as
proved by the "ground truth" of meteorite finds) have a value presently in the
order of $1,000 per ounce or $30 per gram. Vastly expanded use in catalysts
and for fuel cells will enhance their value, and PGM recovery from asteroid
impact sites on the Moon is the basis of Dennis Wingo's book, "Moonrush.“”

5. Value of Materials
One NASA report estimates that the mineral wealth of the
asteroids in the asteroid belt might exceed $100 billion
for each of the six billion people on Earth. John S. Lewis,
author of the space mining book Mining the Sky, has
said that an asteroid with a diameter of one kilometer
would have a mass of about two billion tons. There are
perhaps one million asteroids of this size in the solar
system. One of these asteroids, according to Lewis,
would contain 30 million tons of nickel, 1.5 million tons of
metal cobalt and 7,500 tons of platinum. The platinum
alone would have a value of more than $150 billion!

6. Professor John Lewis has pointed out (in
Mining the Sky) that the resources of the
solar system (the most accessible of
which being those in the NEAs) can
permanently support, in first-world
comfort, some quadrillion people.

7. Resources
7

8. Mineral Content
 Spectroscopic studies suggest, and ‘ground-
truth' chemical assays of meteorites confirm,
that a wide range of resources are present in
asteroids and comets, including nickel-iron
metal, silicate minerals, semiconductor and
platinum group metals, water, bituminous
hydrocarbons (Ralph: think OIL like materials),
and trapped or frozen gases including carbon
dioxide and ammonia.

9. Mineral Content
 Even a relatively small asteroid with a diameter of one kilometer
can contain billions of metric tons of raw materials.
 “In 1989 the world production of iron ore reached a local peak of
928,054 metric tons prior to the collapse of the Warsaw Pact. In
comparison, a comparatively small M-type asteroid with a mean
diameter of 1 km could contain more than 3 billion metric tons of
iron-nickel ore, or 3,000 times the annual production for 1989. (In
other words, more iron ore than has ever been mined in human
history.) A small portion of the extracted material would also contain
precious metals, although these would likely be more difficult to
extract. “

10. Platinum Elements
 “As one startling pointer to the unexpected
riches in asteroids, many stony and stony-iron
meteorites contain Platinum Group Metals at
grades of up to 100 ppm (or 100 grams per
ton). Operating open pit platinum and gold
mines in South Africa and elsewhere mine ores
of grade 5 to 10 ppm, so grades of 10 to 20
times higher would be regarded as spectacular if
available in quantity, on Earth.”

11. Helium-3
 “Researchers see helium-3 as the perfect fuel source: extremely
potent, nonpolluting, with virtually no radioactive by-product.
Proponents claim its the fuel of the 21st century. The trouble is,
hardly any of it is found on Earth. But there is plenty of it on the
extraterrestrial bodies (the moon and asteroids). “
 “"Helium 3 could be the cash crop for the moon (and asteroids),"
said Kulcinski, a longtime advocate and leading pioneer in the field,
who envisions the moon becoming "the Hudson Bay Store of Earth.
"Today helium 3 would have a cash value of $4 billion a ton in terms
of its energy equivalent in oil, he estimates.

12. Water
 Water is an obvious first, and key, potential
product from asteroid mines, as it is a highly
prized resource in outer space. (Think
Moon/Mars Colonies)
 Water could also be broken down into hydrogen
and oxygen to form rocket engine propellant.
(not only what we need to get stuff back home,
but also a very valuable commodity to sell to
other space faring companis)

13. Energy
 Solar Arrays – think 24 hour a day sunlight
 Nuclear
 (can’t build this kind of stuff on earth)

14. Extraction and
Processing
14

15. Mining
 There are two options for mining:
 Bring back raw asteroid material.
 Process it on-site to bring back only processed materials, and
produce fuel propellant for the return trip.
 Processing in situ for the purpose of extracting high-
value minerals will reduce the energy requirements for
transporting the materials to the point of manufacture.
However the processing facilities must then be
transported to the mining site. Thus there is an
economic trade-off.

16. Mining (cont’d)
 Mining and processing an asteroid is much less massive an operation than Earth or
Moon mining. We do not need heavy mining and transport machinery, we don't need
complex chemical processing as on the Moon in order to get valuable materials, and
waste disposal is achieved by just putting all waste into a big bag. However, the near
zero-gravity space environment has its unique challenges as well.
 A typical asteroid would probably be crumbly, consisting of silicate dirt embedded
with nickel-iron granules and volatiles. We can make this assumption for the
purposes of this analysis, but should be aware that the consistency from asteroid to
asteroid can vary from pure metal to pure powder, and could also entail a mix of
consistencies.
 Many different methods have been discussed for mining the asteroid. Conventional
methods include scraping away at the asteroid's surface (i.e., strip mining), and
tunneling into the asteroid. Most Earth mining depends upon gravity to hold the
cutting edge against the ore. (However, for many Earth mining operations this is not
enough, and other means are employed, e.g., cables and reels.) Scraping away at
the surface of the asteroid requires holding the cutting edge against the outer surface
of the asteroid. This would require either local harpoons or anchors imbedded into
the surface of the asteroid, or cables or a net around the asteroid for the cutter to
hold onto.

17. Mining (cont’d)
 Strip mining would result in a lot of dirt being thrown up. An unconventional space mining method
sees this not only as a problem but also as an opportunity. A canopy around the mining site can be
used to collect ore purposely kicking up, the canopy shaped and rotating to use the centrifugal force
to channel the ore to the perimeter for collection, as this NASA artwork shows. If no canopy were put
up, a lot of debris would cloud and cover the mining environment and probably interfere with mining
operations. (Mining without a canopy would certainly be unacceptable in Earth orbit. Companies will
most probably use a canopy also because the canopy would be quite profitable in terms of the
amount of loose ore it would collect.)
 A variation on this is to have a stationary canopy. A dust kicker goes down to the asteroid and just
kicks up the ore at low velocity. When there's enough ore in the canopy, it's sealed off and moved to
the processing site (where the ore can be collected by rotation or other mechanical means). It is
simple and highly reliable, presenting minimal risk of breakdown of mining machinery.
 Some studies adopted tunneling to mine an asteroid. The cutter holds itself steady by the walls of
the tunnel -- pushing against the walls or cutting into them. Tunneling prevents consumption of the
entire asteroid, but desirable ore veins or cracks can be followed.
 Another candidate process for extracting volatiles from within near Earth asteroids which are
dormant comets (currently estimated to be around 40% of near Earth asteroids) is to drill into the
asteroid, much like we do for oil and natural gas. Geological and Mining Consultant David L. Kuck of
Oracle, Arizona, proposes in a long paper entitled "Exploitation of Space Oases" some highly
automated methods of drilling and producing volatiles without the need for extraction of materials
and thus without dealing with the crushing, grinding and tailings disposal.

18. Mining Mechanisms
 One of the difficulties in mining an asteroid will be the rotation period of the body. It may be
necessary to attach rockets to the asteroid in order to eliminate the spin before mining can
commence. Alternatively, the mining operation can be placed at the pole of the asteroid, or asteroids
with high rates of rotation can simply be avoided.
 The mining operation will require special equipment to handle the extraction and processing of ore in
outer space. The machinery will need to be anchored to the body, but once emplaced the ore can be
moved about more readily due to the lack of gravity. Docking with an asteroid can be performed
using a harpoon-like process, where a projectile penetrates the surface to serve as an anchor then
an attached cable is used to winch the vehicle to the surface.
 There are several options for material extraction:
 Material is successively scraped off the surface in a process comparable to strip mining. The digging machine
will need to be anchored against the asteroid using a series of attachments, then cut into the surface using a
blade. The drawback to this approach is the large amount of loose material that will collect in the low-gravity
environment about the asteroid.
 A mine can be dug into the asteroid, and the material extracted through the shaft. This eliminates the problem of
producing loose material, but it would require a transportation system to carry the ore to the processing facility.
Potentially the microgravity environment can be exploited to move the material to the surface.
 Ultrasonic/Laser Mining
 Due to the distance from Earth to an asteroid selected for mining, the round-trip time for
communications is likely to be on the order of a minute or more. Thus any mining equipment will
either need to be highly automated, or a human presence will be needed nearby. Humans would also
be useful for troubleshooting problems and for maintaining the equipment. So, at least until
automated space mining technology improves sufficiently, the mining facilities would need to be
accompanied by a sealed-environment habitat. The operation is also likely to be of long duration, so
the health risks of weightlessness would need to be managed and the crew would require a shelter
against radiation from solar flares. A habitat mounted on the asteroid and covered by surface

19. Mining Equipment Postulates
 The machinery will likely be solar powered, to reduce the need for fuel that would have to be
hauled to the asteroid by spacecraft.
 The equipment will also have to be lightweight to transport it to the asteroid.
 Some experts, including Lewis, have favored using robotic equipment to limit the personnel
needed to carry out the mining project. This would reduce the amount of supplies, like food,
required for a manned mission.
 Miners on asteroids would use techniques similar to those used on Earth. The most likely
method would be to scrape desired material off the asteroid, and tunnel into veins of specific
substances. Scraping, or strip mining, will pull out valuable ore that will float off the asteroid.
 Because much of the ore will fly off, a large canopy might be used to collect it.
 Asteroids have nearly no gravity, so the mining equipment, and the astronaut-miners who
operate it, will have to use grapples to anchor themselves to the ground. However, the lack of
gravity is an advantage in moving mined material around without having to use much power.
 Once a load of material is ready to be sent to either Earth or a space colony, rocket fuel for a
ferrying spacecraft could be produced by breaking down water from the asteroid into hydrogen
and oxygen.
 After an asteroid's minerals and resources have been exhausted by the mining project, the
equipment can then be transported to the next asteroid.

20. Processing
 Asteroidal material in general is exceptionally good ore requiring a minimum of
processing, since it has free metal already.
 Only basic ore processing need occur at the asteroid, producing free metal and volatiles
(usually stored as ices), and perhaps selected minerals, glasses and ceramics. The
required equipment is quite simple.
 The following is a sample ore processing system, but is not the only one proposed to date.
 At the input chute, the ore will be ground up and sieved into different sizes as the first step
of a basic ore processing system. Most asteroids probably offer far more crumbly material
than we could consume in one mining expedition.
 Simple mechanical grinders, using a gentle rocking jaw arrangement for coarse crushing
and a series of rollers for fine crushing, could be arranged in a slowly rotating housing to
provide centrigufal movement of the material. Vibrating screens are used to sift the grains
for directing them to the proper sized grinders.
 The streams of material are put through magnetic fields to separate the nickel-iron metal
granules from the silicate grains. Alternatively, the streams can be dropped onto magnetic
drums, whereby the silicates and weakly magnetic material deflect off the drum whereas
the magnetic granules and pebbles stick to the magnetic drum until the scrape off point.
Repeated cycling through the magnetic field and perhaps additional grinders can give
highly pure bags of free nickel iron metal.
 An optional additional piece of equipment is an "impact grinder" or "centrifugal grinder"
whereby a very rapidly spinning wheel accelerates the material down its spokes and flings
it against an impact block. Any silicate impurities still attached to the free metal are
shattered off. It's feasible to have drum speeds sufficient to flatten the metal granules by
impact. A centrifugal grinder may be used after mechanical grinding and sieving, and
before further magnetic separation. In fact, most of the shattered silicate will be small
particles which could be sieved out.

21. Processing (cont’d)
 The nonmagnetic material is channelled into a solar oven where the volatiles are cooked out. In zero gravity and
windless space, the oven mirrors can be huge and made of aluminum foil. The gas stream is piped to tanks
located in a cold shadow of space. The tanks are put in series so that the furthest one away is coldest. This way,
water condenses more in the first one, carbon dioxide and other vapors in the tanks downstream.
 Rocket fuel for the delivery trip to Earth orbit can be produced by separating oxygen and hydrogen gases from
the mix, or by electrolysis of water. Alternatively, the hydrogen could be chemically bonded with carbon to
produce methane fuel. On the simpler end, simple steam rockets could be used. This is all discussed in chapter 3
on transportation in space.
 Thin, relatively lightweight spherical tanks could be sent to store the frozen volatiles. Ultimately, tanks for storing
frozen volatiles for sending to Earth orbit can be manufactured by some of the nickel iron metal, by use of a solar
oven for melting the nickel iron metal. A cast can be made from sand or glass-ceramic material from melted
leftover ore.
 Some silicate material from the asteroid can be shipped back to Earth orbit to be used for making glass,
fiberglass, ceramics, "astercrete", dirt to grow things in, and radiation shielding for habitats and sensitive silicon
electronics.
 Processing of glasses, ceramics, "astercrete" and the like is not discussed here, because it is discussed in the
chapters on lunar material utilization and space manufacturing. If we were to not use lunar materials but use only
asteroidal materials, processing asteroidal material to make glasses, ceramics and astercrete is analogous to the
discussion on processing lunar materials for the same feedstocks and products.
 Undesired material can be put in a big wastebag container, or "sandbags", or cast into bricks by a solar oven,
used for shielding the habitat from space radiation, creating more cold shadows, or just removed from the mining
operation's space. (If waste were simply ejected at escape velocity, it would not significantly increase the number
of meteors in interplanetary space. However, it's cheaper to skip the ejector equipment and just bag it all.)
 Finally, I should add that some studies consider processing all the asteroidal material by solar oven, skipping the
magnetic separators, impact grinders, etc. This approach would utilize giant superlightweight mirrors to
concentrate sunlight onto a cavity containing any matrix of material, to first extract the volatiles, and then raise
the temperature to more than 1600C (2900F). Only the free metal would melt at the latter temperature. However,
separating the molten metal from the silicate matrix seems a little tricky. Thus, I don't review that alternative here.
Similar methods, "vacuum vapor distillation" as well as high temperature electrolysis, are discussed in chapter 4
on industrial processes

22. Customers
22

23. Usage of Materials on Earth

24. Usage of Materials in Outer Space
 On the Moon
 In Orbit
 During exploration/colonization
 Will Catalyze the colonization of space – but colonization
(moon, mars, space) will require massive amounts of
minerals, energy and water…
 Potential to be able to make own propellant out of
asteroid minerals
 Current cost to launch materials from the earth =
~$10,000 per kg.

25. “Development and operation of future in-orbit
infrastructure (for example, orbital hotels,
satellite solar power stations, earth-moon
transport node satellites, zero-g manufacturing
facilities) will require large masses of materials
for construction, shielding, and ballast; and also
large quantities of propellant for station-keeping
and orbit-change maneuvers, and for fuelling
craft departing for lunar or interplanetary
destinations. “

26. Spinoff Technologies
 Lots of opportunity along the way for sale
of, or licensing of the technologies we
create – to military, and private sector.
 Worst case scenario, we end up just being
a research and dev company that makes
mucho dinero by selling the stuff we
create to other people taking the risk.

27. Getting there and
Back
27

28. Prevalence of Asteroid Matter in Near
Space
Not just one
ring, these
bodies of
minerals are
everywhere
in the solar
system…
Millions of
them.

29. Near Earth Opportunities and
Targets
 Some of these near earth asteroid bodies have orbits that bring them very close to earth –
allowing very low energy/effort to return production materials to earth/earth orbit.
 “The most accessible group of NEAs for resource recovery is a subset of the Potentially
Hazardous Asteroids (PHAs). These are bodies (about 770 now discovered) which approach to
within 7.5 million km of earth orbit. The smaller subset of those with orbits which are earth-orbit-
grazing give intermittently very low delta-v return opportunities (that is it is easy velocity wise to
return to Earth). “
 “The Near-Earth asteroids orbit in close proximity to the Earth and are considered likely
candidates for early mining activity. Their low delta-v location makes them suitable for use in
extracting construction materials for space-based facilities, greatly reducing the economic cost of
transporting supplies into Earth orbit. “
 “One potential source for an early asteroid mining expedition is 4660 Nereus. This body has a
very low delta-v compared to lifting materials from the surface of the Moon. The velocity
difference from low earth orbit is only 60 meters per second (compared to 9,000 meters per
second to reach orbit from Earth.) However it would require a much longer round-trip to return
the material. So most likely it would require an automated mining mission for economic reasons.
“

30. Launch Technologies
 N.B. a large number of these objects are
substantially closer to Earth than the
moon, and thus easier to reach at much
lower expenditures of energy/cost.

31. LiftPort
 http://www.liftport.com/
 Think – space elevator.

32. Transport
 Rail Gun
 Ion Drive
 Self – Generated Propellant (out of Water)
 Return to Earth – “About 10% of Near-Earth Asteroids are
energetically more accessible (easier to get to) than the Moon (i.e.
under 6 km/s from LEO), and a substantial minority of these have
return-to-Earth transfer orbit injection delta-v's of only 1 to 2 km/s.
 Return of resources from some of these NEAs to low or high earth
orbit may therefore be competitive versus earth-sourced supplies.”

33. The Interplanetary Transport
Network (requires Patience)
 http://www.answers.com/main/ntquery;jsessionid=6mw7syc
 Uses gravity assist to create transport lanes
throughout the solar system. Movement of materials
through these lanes is slow, but also very cheap…
setting up a steady stream of deliveries – first one
wouldn’t arrive for some time, but after that they’d
arrive in a continuous stream at regular intervals.

34. Competition
 So far, the only competition I can find
(other than NASA and other space
agencies having considered the
feasability) is a company called
SpaceDev.
 http://www.spacedev.com/newsite/templat
es/homepage.php?pid=2