Mines on asteroids: science fiction or new frontier?
Some claim that the colonization and exploration of the Solar System will begin for real only when
humanity will begin to exploit economically the minerals rich in asteroids. Although the
concept has been proposed for decades by science fiction, it is only in recent years that it has
been seen as a serious possibility. This has even led to the creation of numerous mining companies
for the exploitation of asteroids. But how close are we really to the realization of this dream?
For many years now, experts, environmental scientists but also geopolitical scholars
and economists, have been telling us that the Earth's natural resources are not infinite,
and that sooner or later (sooner than later, considering the continuous growth of the world's
population and consumption), they will run out. These are not only energy resources such as fossil
fuels, which in addition to being increasingly scarce are also harmful to the environment,
but also and above all the metals and other minerals used for the countless industrial
processes necessary for contemporary society. We are talking about phosphorus,
antimony, zinc, tin, lead, indium, silver, gold and copper, platinum, cobalt ... All minerals
that the earth's crust now struggles to provide us in the right amount and at affordable costs.
The most sought after minerals are present in limited quantities in the Earth's crust,
and once they are all extracted and used there will be no magic hand ready to replace them.
Already now the control of the extraction and export of rare minerals plays a very important
role in the economy and in the relations between states, and in some cases is a cause
of tensions and conflicts; a scenario that will be repeated more and more often in the future.
We have already seen, for example, that the almost monopoly owned by China
on the extraction and trade of some fundamental elements for the production
of electronic components, the so-called "rare earths", has given that country a considerable
advantage over other industrial powers. There are not many solutions to face the
inevitable depletion of some minerals on Earth. Experts urge to reduce waste and
develop new mining and industrial processes that are more efficient and require fewer resources.
Another possible way is that of recycling: every object no longer usable must be demolished
and the materials that make it up must be reused for new processes. But this does not
mean that if industrial production continues to grow at the pace of the last 50 years,
the day will come when the Earth's mineral resources will not be sufficient and sustain it.
However, there is another solution, very easy to think about but much harder to put into practice:
if the mineral resources of the planet are going to end, just start looking for them and
get them outside the Earth, in space! It may seem like a classic science fiction scenario,
with large space stations extracting resources from distant moons, and colonies of miners on
other planets in the Solar System. But someone on Earth already believes that such a scenario is not
so futuristic, and is investing dizzying sums in what will probably be the new economic, scientific
and social frontier: the colonization of space and the exploitation of its mineral resources.
But why should we go into space to look for rare metals on uncomfortable and very small celestial
bodies like asteroids, when we have at our disposal a whole planet to dig? The reason, apart
from the progressive scarcity of materials we have already talked about, lies in the fact that when
our planet was still in a state of fusion, gravity made all the heavier elements sink into the core.
This has depleted the earth's crust of all metals, until an authentic asteroid bombardment,
which occurred from 4.1 to 3.8 billion years ago, brought back to the surface all those minerals
that we are still extracting today, essential for our economic and technological progress,
but increasingly difficult to identify. On the asteroids, apart from those of planetary size,
gravity has not had any influence. On the contrary, the many impacts to which they
have been subjected, and which have fragmented them, have certainly meant that somewhere the
heavy minerals we are looking for are close to the surface, and therefore easy to detect and extract.
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Most of the asteroids currently known are of three main types:
type C (the so-called Chondritis) includes dark, porous, and predominantly carbon asteroids,
They are perhaps the most valuable, being rich in water. Astronauts need this vital resource
not only as a drink and to hydrate food, but also because it is a very efficient radiation shield.
The type S - more common, and which includes most of the asteroids in the Main Belt - includes
asteroids that are on average denser, and composed mainly of silicates. They are also
rich in platinum group metals (ruthenium, rhodium, palladium, osmium and iridium).
And type M. Much rarer, but consists of asteroids with very high metal content. Just to say,
the asteroid UW158, which passed in the vicinity of the Earth in 2015, has a diameter of about half
a kilometer and is estimated to contain precious metals worth about five trillion dollars...
Having an efficient and rapid strategy to differentiate the three types
will be necessary to select the most suitable targets for a mining mission.
Unfortunately, apart from a few samples that have been reported to us from a few missions,
the only way we have to study the composition of asteroids is to analyze the light reflected
from their surface, or examine the fragments that have arrived on earth, in the form of meteorites.
But these methods have big limits, since "spectroscopic observations are related to the
outer "layer" of the asteroid, which is exposed to space and subject to other processes that
alter its composition. Meteorites are crucial, but they also tell only part of the story:
the most fragile elements contained in asteroids may have been destroyed during the crossing of the
atmosphere. Another possible method to classify asteroids is to identify "families" (groups of
asteroids resulting from the fragmentation of one or more common "ancestors"), able to indicate
groups with similar internal composition. But even if the best targets are identified,
engineering problems remain: what can be the best technique for excavation in the absence of
gravity, and not yet knowing the consistency and thickness of the layer of regulite of asteroids?
And what tools will be needed to extract materials from within them?
It is believed that, from 10 meters up to almost a thousand kilometers in diameter,
our Solar System can count on tens of millions of asteroidal objects. Obviously, at least for
the first time, we will need to choose the best targets among those that orbit as close to the
Earth as possible... that is, among more than 15,000 objects called NEO (Near Earth Objects)
observed and cataloged for their characteristic of dangerously approaching the Earth. In practice,
NEOs represent both a threat and a resource, and the technologies needed to bring asteroid
resources into Earth orbit will certainly also allow to develop methods to divert objects
at high risk of impact. But how many asteroids are
potential mining hotspots? Martin Elvis, an astrophysicist at Harvard University with an
interest in asteroid mining, developed an equation in 2013 to estimate the number of asteroids that
could be potential candidates for mining with our current technology. The equation takes into
account the number of asteroids within reach of today's rocket ships, the likelihood that they
are worth extracting, whether it is practically possible to extract them, and whether it would
make a profit. When he first analyzed the numbers in 2013, Elvis estimated that about
10 potentially metal-rich and 18 sufficiently water-rich asteroids are within our reach.
All easy, then? Not really... Currently, the mining of asteroids is considered a
completely speculative project, whose immediate implementation is burdened by huge start-up costs.
Despite this, more and more private companies are emerging with the explicit purpose of prospecting,
exploration and extraction of asteroids, and it is clear that this wonderful idea
is now moving from the realm of science fiction to the world of scientific facts.
Obviously, asteroid mining companies must first convince potential lenders that such a venture
is credible and achievable, and progress is already underway. The first company ever,
Planetary Resources, was founded in 2012, followed by Deep Space Industries. Since then,
dozens of them have been born, and although some are certainly less serious than others,
it can be said that the race to the riches of space has officially begun.
One day, companies like these will bring to Earth metals for the production of electronic devices
and catalytic converters, minerals that will be transformed into rocket fuel, or materials
to use to print 3D structures in space... But it is the opinion of many that all this
turmoil will only get results once the economy based on human presence in commercial orbit takes
off (space stations, permanent bases on the Moon, etc.). Only then a market will open. And only then
will the market automatically create the technical capacity to access the resources of NEOs.
In short, we are faced with a new Klondike, a "gold rush" which could potentially
yield twelve-figure revenues (thousands of billions of dollars, to put it mildly)...but
this time it won't be enough to equip oneself with a spirit of adaptation,
shovels and strong arms in order to succeed. It will be necessary to design specific spacecraft,
build them, plan reconnaissance missions, survey and transport the precious cargo here
on our planet, and, if the human crew is expected, provide adequate training for future astro-miners.
All this is not improvised, it takes enormous economic and human resources investments,
as well as a lot of foresight. NASA, for its part, has already shown a real interest in this area,
and has already presented the New Asteroid Initiative a few years ago to choose an
asteroid suitable to be captured, dragged on an intermediate orbit between Earth and Moon
and then explored by astronauts in the flesh. But if the West is moving, China is already a
little bit further... A private Chinese company, Origin Space, has announced
its intention to launch in space by the end of 2020 an asteroid extraction robot called NEO-1. It
will depart aboard a Long March rocket, provided by the China National Space Administration,
to encourage private companies to start extracting space resources.
The robot will be used to test the technologies and sequences
needed to land on an asteroid, search and identify materials
and then start extracting them. And also to simulate the capture of small asteroids.
How many years will it take to get the first results? How long will it take before a "space
tugboat" delivers a beautiful mountain to our home, in lunar or terrestrial orbit?
Certainly not the 10 or 20 years that private companies have been promoting, also because as
you can see in the video "Mines on asteroids? Here's how we will do" - always available here
on "Insane Curiosity Channel" - the obstacles to overcome are also political and legal...