One of the principal problems in carrying out a manned mission to Mars, as NASA plans (for the 2030’s) and SpaceX (in 2024, Elon Musk believes), are the resources in order to sustain the astronauts alive during a considerable amount of time. We humans need water, food, oxygen, … and in the case of interplanetary space flight, enough fuel to get home.
The International Space Station uses electric energy derived from solar power, it has a water recycling system (that makes potable that which is used to brush the astronaut’s teeth, to even their sweat and urine), a system for the production of oxygen from that very water (via a process called electrolysis which separates the hydrogen from the oxygen, the hydrogen then traveling outside of the vessel, and the oxygen staying within it). In this way, humanity has been able to reduce the cost of the transport of these resources from earth, which is very costly, giving the astronauts a certain level of independence or sustainability (which is quite valuable especially in times of crisis).
Of course, even the food is brought from earth, because plants have required too much water to grow, and take up too much space in the ship. Every now and then, the station receives refueling brought from our planet.
But the International Space Station is only 254 miles / 408 km from the earth in orbit, a distance that this past October 15 three astronauts traveled in a Russian Soyuz ship. Mars, on the other hand, is 225 million kilometers away (in its most favorable orbital position), which represents a trip of at least 6 months. Even if the crew on Mars would be able to wait, there still remains a question of whether it would be able to be sufficiently supplied with one trip. After all, the amount of weight a ship can transport is limited, because the more weight it carries, the more “effort” it employs to move, and the more fuel it burns.
This is one of the principal reasons why NASA is advocating for In-Situ Resources Utilization or ISRU, which is to say, the production of resources with materials supplied by the destination planet or body.
There has already been the development of MOXIE (Mars Oxygen ISRU Experiment), an experimental tool included in the Perseverance rover which takes the carbon dioxide of the martian atmosphere (which comprises 96% of it), and converts it into oxygen. This oxygen can not only be utilized for supporting human life, but also as an oxidant for the propulsion of rockets, incredibly important for assuring the return of the astronauts.
There has also already been liquid water discovered on Mars, albeit in highly saline subterranean lakes. This means that in order to obtain this resource, excavation would be necessary (and later, desalination). Once again, the water would not only be for the hydration of the astronauts, but also for propulsion (for instance, using it to form hydrogen peroxide, a monopropellant).
To get the water, NASA has designed RASSOR (Regolith Advanced Surface Systems Operations Robot), a device for the extraction of water, ice, and regolith from the martian and lunar surfaces (but also for use on comets and asteroids).
This represents a strong advance towards space mining, a fundamental aspect of ISRU, beyond its possible applications on Earth (like the possible replenishment of industrial minerals which are considered in danger of being exhausted, like zinc, silver, lead, copper, and tin, among others).
The idea of asteroids being an opportunity to mine is not new. The first samples of them we have are from 2010, when the Japanese probe Hayabusa (launched in 2003), returned to Earth with small particulates of the asteroid Itokawa, which were found to contain iron sulfide, taenite (an alloy of iron and nickel), olivine, pyroxene, plagioclase, and chromite (principally chromium and iron, with some other metals). This is a combination of minerals that, incidentally, does not exist on Earth.
Asteroids can be classified according to their spectral appearance (what type of light they reflect) and composition into various types. The most basic, which are also found in the famous Asteroid Belt between Mars and Jupiter (the closest to us) are types M (metallic), S (silicate), and C (carbonaceous).
In spite of this classification and the predominance of one specific element, each asteroid has its own unique composition. The asteroid Ryugu, for example, belongs to type C, but although it is carbon based, it also contains considerable quantities of nickel, iron, cobalt, nitrogen, hydrogen, ammonia, and water. And yes, we must mention, it has the estimated value of 87.76 billion dollars, according to the database Asterank. Because of this, it is also not surprising that there would already be companies dedicated to space mining, like Planetary Resources (now belonging to ConsenSys), that develop technology to bring the activity to pass, or the English Asteroid Mining Corporation, which is going down a path toward a similar goal.
It is believed that the resources of one single asteroid would be able to satisfy our needs for thousands of years. Space mining, therefore, could be able to reduce the environmental impact of terrestrial mining. And this is only in respect to Earth. Asteroids, furthermore, could provide us with essential resources for the exploration of space, or for the construction of spatial infrastructure that could guarantee the survival of humanity beyond Earth.
Although there is still a long road ahead, it is evident that this is no longer science fiction. The mining of the future is, officially, in front of us.
Editor’s note: ConsenSys has made Planetary Resources’ patents and IP available for use to all it says use them in good faith.