Mines on asteroids? Here is how we will do
In the previous video "Mines on asteroids: science fiction or new frontier?" we talked about why it
seems necessary for the human species to turn its attention to the exploitation of mineral resources
outside its home planet. But between necessity and feasibility there is a sea of technical and
even legal problems. Nothing really insuperable, but the smell of a design vagueness that will
certainly not allow to grasp the results of so much work before the end of this century.
But we must not exaggerate with criticism. A lot of work, in fact, has already been done...
And even if it does not seem so, it is already several years that the same government agencies
have committed themselves to design and carry out missions that involve the descent of probes
on the surface of asteroids and comets. The first to do so was NASA in 2001, when
the NEAR probe landed on the asteroid 433 Eros, one of the largest and best known NEOs, about 33
km long. In 2014, instead, the enterprise of the Rosetta probe, launched ten years earlier by the
European Space Agency, aroused great sensation all over the world. You will all remember how after
having flanked the comet Churyumov-Gerasimenko, approaching the Sun, the probe released the lander
Philae, which landed on the frozen core analyzing its composition and sending the data to Earth.
Without forgetting that just in these months the NASA mission Osiris-Rex
has landed on the asteroid Bennu, with the task of collecting material to bring home in 2023.
But the most significant precedent for future space miners is the lesser known one of the
Japanese probe Hayabusa ("peregrine falcon" in Japanese). Launched in 2003 and equipped
with a futuristic ion engine, in 2005, after a journey of over 290 million kilometers,
Hayabusa landed on the Itokawa asteroid; from where it took tiny rock samples that it then
brought to Earth in 2010. A feat then repeated by the Hayabusa 2 mission that in 2019 landed
on the asteroid Ryugu, and that just in these days should be back to Earth with its load of samples.
NASA is also respecting the stages that should lead to the start of the Psyche
Mission in the summer of 2022, when a probe will leave for the huge homonymous asteroid
that is located in the belt between Mars and Jupiter. Arrival expected in 2026.
Psyche is an asteroid that according to spectral analysis contains large amounts of gold. It is
also one of the largest asteroids in the Solar System with its diameter of about 250 km.
Strangely, despite its size, Psyche seems to be made mainly of iron and nickel, a composition
similar to that of the Earth's core. For this reason, scientists suspect that the object may be
the exposed core of an ancient planet, whose rocky outer layers were torn away by impacts long ago.
Of course, picking up small fragments of asteroid and bringing them back to Earth is
something quite different from setting up mining stations on huge space rocks orbiting millions
of kilometers from our planet, and then bringing back the tons of extracted material. But having
managed to develop in a few years a technique that allows to settle on the ground of those
rotating mountains is already a good goal, and a good basis to start planning the next steps.
To understand what to do after going down on an asteroid and digging hundreds of tons of material
it is necessary to think about the fact that the most important resource to have available in space
is not gold, platinum or diamonds, but water! This liquid, abundant on Earth, is in fact one
of the main ingredients of the fuels that will make rockets and spacecraft travel. And it's
tremendously expensive to start it from Earth, even just the one to be drunk by astronauts in low
orbit (sending a liter of it to the Space Station costs about 40 thousand dollars...). Currently
the spaceships have to be supplied with all the necessary fuel and this limits very much their
loading and displacement capacity: just think that just to escape from the Earth's gravitational
field you consume from 5000 to 10.000 dollars of fuel for every kilogram of weight.
Imagine having to face a long-range mission, carrying everything from home with you;
it would be like thinking to go around America through Route 66 by motorcycle,
carrying all the fuel crammed in big tanks. Where do you put them? To make the first 300
km in orbit around the Earth you need more energy than to make the remaining 300 million kilometers.
And this is where asteroids come into play: water can be extracted relatively easily from
the clay minerals of a class of asteroids called "carbonaceous" or "type C"; then, through trivial
processes of electrolysis, hydrogen and oxygen can be separated to produce propellants for rockets
and spacecraft. All this could then start a supply chain, and more generally a transport network
completely outside the Earth, with considerable advantages for planetary colonization.
That the Earth should be cut off from the space economy can also be understood by another example.
When we talk about mining from asteroids, we mention rare elements that, once brought to Earth,
could be worth billions of dollars, but in reality we forget that if a huge amount of
any material asset is put on the market, it will become less rare and therefore much less
valuable. And if you go so far as to bring small quantities to Earth just to keep prices high,
how could space companies compete with companies that work on Earth and already
extract this material at infinitely lower costs? So the starting idea must be to extract resources
in space to use them in space, and not to bring them to Earth!
To start programs of this kind there is however (at least) a critical problem that must be faced
and solved: choose the right asteroid, the one that can economically repay the initial effort.
In this will be important the contribution of astronomers, who will have to choose the asteroids
with extreme care: some to obtain 'water, thus creating refueling stations for spaceships
traveling in the Solar System, others for the minerals needed for our technology. It will
be necessary to know which ones to discard, so as not to waste resources unnecessarily.
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With a large telescope equipped with a last generation spectrograph
you could have a picture of the characteristics of an asteroid in 2-3 minutes:
this would allow a first skimming, perhaps even 80-85%, but there would remain a good
number of promising targets to which to direct exploratory probes to verify the data collected.
This research is comparable to that conducted by geologists on a mining area of the Earth
studying it from the sky: if it is assumed that in a certain area there are minerals or other useful
resources, before digging the geology helps to calculate the costs and benefits. In the same way,
for asteroids, large telescopes could allow the abatement of a factor of 10 of the survey costs.
Once a final exploration mission has been carried out to confirm that it is
worth digging the asteroid, the target is set and the actual extraction should take place. And
that's when things get (even more) interesting: there are many ideas about the actual construction
of the infrastructure and extraction techniques, but there are too many variations to consider:
until we actually get there there there is nothing that can be said to be really safe. All we know is
that once the extraction is finished, it should be relatively easy and not too expensive in terms of
energy to lift and store the materials, thanks to the negligible gravity of the asteroids.
Some minerals will be brought back to Earth, but many more will be used in space to provide energy
for the mining industry itself and to support the needs of space infrastructure and settlements.
But there is one aspect that should not be underestimated in this space
race that may seem purely economic in nature. Being able to create an industrial chain able to
extract precious metals from an asteroid and then send them to Earth or wherever Man is settling,
would significantly reduce pollution in the regions of the planet
where there are mines and mining activities. It is estimated that annually more than
28,000 tons of lead and almost 2000 tons of mercury are released into the environment,
along with other toxic substances used to allow the extraction of gold, iron, aluminum,
platinum and other precious metals. If these mining activities could be moved into space,
perhaps for the first time in human history we could separate the economy from ecology.
In addition, there are many advantages in trying to expand the research and processing of resources
outside of the Earth. Here on our planet, in fact, mining activity has a considerable impact
on the natural environment. And depending on the methods used, it can cause erosion,
sinkholes, habitat destruction and destruction of native plant and animal life.
There are also the dangers of toxic runoff and contamination of soil, groundwater and
surface water, which is a danger to humans as well as wildlife and the natural environment.
Together with energy production, these industrial processes are some of the main contributors to air
and water pollution. Meanwhile, we still need to find solutions to the problems of overpopulation,
hunger, resource depletion and climate change, which emphasize
sustainability and green technologies. By shifting these burdens away from the world,
humanity could drastically reduce the impact that such mining has on the natural environment.
We have reached the end of a long history, and although there is still a great deal to do,
we are ready to make the final leap. We are facing unexplored territories,
immense resources just waiting to be discovered... an unlimited frontier to conquer.
If two centuries ago it was the gold rush and the lands of the west that forged our spirit
of adventure, today the rush continues as far as the asteroids that wander above our heads;
and today's gold is as blue as the water they contain. It sounds like science
fiction but soon it won't be anymore. In other words, it is no longer a
matter of "we can" or "we should", but only of "when will we do it?".
However, commercial missions on asteroids may soon face a challenge that will not be in the technical
or scientific field, but in the legal one. A United Nations treaty of 1967,
the Outer Space Treaty, states that "outer space, including the Moon and other celestial bodies,
must be considered free from claims of sovereignty by states.
In practical terms, it means that "no country can claim ownership of the Moon or asteroids".
At the time of signing the treaty, the main states involved in the negotiations
did not consider the possibility that the treaty would constrain private companies
interested in investing and operating in space exploration. So that in this regard the treaty
could be interpreted in a thousand different ways. Suffice it to say that while Article 2 of the
treaty explicitly prohibits the appropriation of the Moon and other celestial bodies,
it is not clear whether this provision should also apply to the resources that can be found there!
Needless to say, such a situation of legal uncertainty risks blocking investments in
this field, or vice versa transforming the space race into a modern Far West.
In fact, there is no international legal framework to deal with the different interpretations of the
United Nations Treaty nor with the territorial disputes in space that could possibly arise.
Despite this, space agencies and space mining companies
continue to develop plans for the next generation of asteroid exploration... It's going to be fun!