Mining In Space


On December 10, 1986 the Greater New York Section of the
American Institute of Aeronautics and Astronautics (AIAA)
and the engineering section of the New York Academy of
Sciences jointly presented a program on mining the planets.
Speakers were Greg Maryniak of the Space Studies Institute
(SSI) and Dr. Carl Peterson of the Mining and Excavation
Research Institute of M.I.T. 

Maryniak spoke first and began by commenting that the
quintessential predicament of space flight is that
everything launched from Earth must be accelerated to
orbital velocity. Related to this is that the traditional
way to create things in space has been to manufacture them
on Earth and then launch them into orbit aboard large
rockets. The difficulty with this approach is the huge
cost-per-pound of boosting anything out of this planet's
gravity well. Furthermore, Maryniak noted, since (at least
in the near to medium term) the space program must depend
upon the government for most of its funding, this economic
drawback necessarily translates into a political problem. 

Maryniak continued by noting that the early settlers in
North America did not attempt to transport across the
Atlantic everything then needed to sustain them in the New
World. Rather they brought their tools with them and
constructed their habitats from local materials. Hence, he
suggested that the solution to the dilemma to which he
referred required not so much a shift in technology as a
shift in thinking. Space, he argued, should be considered
not as a vacuum, totally devoid of everything. Rather, it
should be regarded as an ocean, that is, a hostile
environment but one having resources. 

Among the resources of space, he suggested, are solar power
and potential surface mines on the Moon and other celestial
bodies as well. The Moon, Maryniak stated, contains many
useful materials. Moreover, it is twenty-two times easier
to accelerate a payload to lunar escape velocity than it is
to accelerate the identical mass out of the Earth's gravity
well. As a practical matter the advantage in terms of the
energy required is even greater because of the absence of a
lunar atmosphere. Among other things, this permits the use
of devices such as electromagnetic accelerators (mass
drivers) to launch payloads from the Moon's surface. Even
raw Lunar soil is useful as shielding for space stations
and other space habitats. 

At present, he noted, exposure to radiation will prevent
anyone from spending a total of more than six months out of
his or her entire lifetime on the space station. At the
other end of the scale, Lunar soil can be processed into
its constituent materials. In between steps are also of
great interest. For example, the Moon's soil is rich in
oxygen, which makes up most of the mass of water and rocket
propellant. This oxygen could be "cooked" out of the Lunar
soil. Since most of the mass of the equipment which would
be necessary to accomplish this would consist of relatively
low technology hardware, Maryniak suggested the possibility
that at least in the longer term the extraction plant
itself could be manufactured largely on the Moon. 

Another possibility currently being examined is the
manufacture of glass from Lunar soil and using it as
construction material. The techniques involved, according
to Maryniak, are crude but effective. (In answer to a
question posed by a member of the audience after the formal
presentation, Maryniak stated that he believed the brittle
properties of glass could be overcome by using glass-glass
composites. He also suggested yet another possibility, that
of using Lunar soil as a basis of concrete.) One possible
application of such Moon-made glass would be in glass-glass
composite beams. Among other things, these could be
employed as structural elements in a solar power satellite

While interest in the SPS has waned in this country, at
least temporarily, it is a major focus of attention in the
USSR, Western Europe and Japan. In particular, the Soviets
have stated that they will build an SPS by the year 2000
(although they plan on using Earth launched materials.
Similarly the Japanese are conducting SPS related sounding
rocket tests. SSI studies have suggested that more than
90%, and perhaps as much as 99% of the mass of an SPS can
be constructed out of Lunar materials. 

According to Maryniak, a fair amount of work has already
been performed on the layout of Lunar mines and how to
separate materials on the Moon. Different techniques from
those employed on Earth must be used because of the absence
of water on the Moon. On the other hand, Lunar materials
processing can involve the use of self-replicating
factories. Such a procedure may be able to produce a
so-called "mass payback ratio" of 500 to 1. That is, the
mass of the manufactories which can be established by this
method will equal 500 times the mass of the original "seed"
plant emplaced on the Moon. 

Maryniak also discussed the mining of asteroids using
mass-driver engines, a technique which SSI has long
advocated. Essentially this would entail a spacecraft
capturing either a sizable fragment of a large asteroid or
preferably an entire small asteroid. The spacecraft would
be equipped with machinery to extract minerals and other
useful materials from the asteroidal mass. The slag or
other waste products generated in this process would be
reduced to finely pulverized form and accelerated by a mass
driver in order to propel the captured asteroid into an
orbit around Earth. If the Earth has so-called Trojan
asteroids, as does Jupiter, the energy required to bring
materials from them to low Earth orbit (LEO) would be only
1% as great as that required to launch the same amount of
mass from Earth. (Once again, the fact that more economical
means of propulsion can be used for orbital transfers than
for accelerating material to orbital velocity would likely
make the practical advantages even greater. ) However,
Maryniak noted that observations already performed have
ruled out any Earth-Trojan bodies larger than one mile in

In addition to the previously mentioned SPS, another
possible use for materials mined from planets would be in
the construction of space colonies. In this connection
Maryniak noted that a so-called biosphere was presently
being constructed outside of Tucson, Arizona. When it is
completed, eight people will inhabit it for two years
entirely sealed off from the outside world. One of the
objectives of this experiment will be to prove the concept
of long-duration closed cycle life support systems. 

As the foregoing illustrates, Maryniak's primary focus was
upon mining the planets as a source for materials to use in
space. Dr. Peterson's principal interest, on the other
hand, was the potential application of techniques and
equipment developed for use on the Moon and the asteroids
to the mining industry here on Earth. Dr. Peterson began
his presentation by noting that the U. S. mining industry
was in very poor condition. In particular, it has been
criticized for using what has been described as
"Neanderthal technology." Dr. Peterson clearly implied that
such criticism is justified, noting that the sooner or
later the philosophy of not doing what you can't make money
on today, will come back to haunt people. A possible
solution to this problem, Dr. Peterson, suggested, is a
marriage between mining and aerospace. (As an aside, Dr.
Peterson's admonition would appear to be as applicable to
the space program as it is to the mining industry, and
especially to the reluctance of both the government and the
private sector to fund long-lead time space projects. 

Part of the mining industry's difficulty, according to Dr.
Peterson, is that it represents a rather small market. This
tends to discourage long range research. The result is to
produce on the one hand brilliant solutions to individual
immediate problems, but on the other hand, overall systems
of incredible complexity are left unanswered. This
complexity, which according to Dr. Peterson has now reached
intolerable levels, results from the fact that mining
machinery evolves one step at a time and thus is subject to
the restriction that each new subsystem has to be
compatible with all of the other parts of the system that
have not changed. 

Using slides to illustrate his point, Dr. Peterson noted
that so-called "continuous" coal mining machines can in
fact operate only 50% of the time. The machine must stop
when the shuttle car, which removes the coal, is full. The
shuttle cars, moreover, have to stay out of each others
way. Furthermore, not only are Earthbound mining machines
too heavy to take into space, they are rapidly becoming too
heavy to take into mines on Earth. When humanity begins to
colonize the Moon, Dr. Peterson asserted, it will
eventually prove necessary to go below the surface for the
construction of habitats, even if the extraction of Lunar
materials can be restricted to surface mining operations.
As a result, the same problems currently plaguing
Earthbound mining will be encountered. This is where Earth
and Moon mining can converge. 

Since Moon mining will start from square one, Dr. Peterson
implied, systems can be designed as a whole rather than
piecemeal. By the same token, for the reasons mentioned,
there is a need in the case of Earthbound mining machinery
to back up and look at systems as a whole. What is
required, therefore, is a research program aimed at
developing technology that will be useful on the Moon but
pending development of Lunar mining operations can also be
used down here on Earth. In particular, the mining industry
on Earth is inhibited by overly complex equipment unsuited
to today's opportunities in remote control and automation.
It needs machines simple enough to take advantage of
tele-operation and automation. The same needs exist with
respect to the Moon. Therefore the mining institute hopes
to raise enough funds for sustained research in mining
techniques useful both on Earth and on other celestial
bodies as well. 

In this last connection, Dr. Peterson noted that the mining
industry is subject to the same problem as the aerospace
industry: Congress is reluctant to fund long range
research. In addition, the mining industry has a problem of
its own in that because individual companies are highly
competitive research results are generally not shared. Dr.
Peterson acknowledged, however, that there are differences
between mining on Earth and mining on other planetary
bodies. The most important is the one already
mentioned-heavy equipment cannot be used in space. This
will mean additional problems for space miners. Unlike
space vacuum, rock does not provide a predictable

Furthermore, the constraint in mining is not energy
requirements, but force requirements. Rock requires heavy
forces to move. In other words, one reason earthbound
mining equipment is heavy is that it breaks. This brute
force method, however, cannot be used in space. Entirely
aside from weight limitations, heavy forces cannot be
generated on the Moon and especially on asteroids, because
lower gravity means less traction. NASA has done some
research on certain details of this problem, but there is a
need for fundamental thinking about how to avoid using big

One solution, although it would be limited to surface
mining, is the slusher-scoop. This device scoops up
material in a bucket dragged across the surface by cables
and a winch. One obvious advantage of this method is that
it by-passes low gravity traction problems. Slushers are
already in use here on Earth. According to Peterson, the
device was invented by a person named Pat Farell. Farell
was, Peterson stated, a very innovative mining engineer
partly because be did not attend college and therefore did
not learn what couldn't be done. 

Some possible alternatives to the use of big forces were
discussed during the question period that followed the
formal presentations. One was the so called laser cutter.
This, Peterson indicated, is a potential solution if power
problems can be overcome. It does a good job and leaves
behind a vitrified tube in the rock. Another possibility is
fusion pellets, which create shock waves by impact. On the
other hand, nuclear charges are not practical. Aside from
considerations generated by treaties banning the presence
of nuclear weapons in space, they would throw material too
far in a low gravity environment. 

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