Over billions of years the earth, other planets and further large astral presences have been hit by asteroids, which have formed a large number of gold, iron, diamond, coal and rare earth mines on our planet that have been and are being mined at a hectic pace and are being exhausted.
For example, the Chicxulub crater with a diameter of 180 km in the Yucatán Peninsula (Mexico) – obtained by the impact of the well-known asteroid, which according to the theories of Spanish-American physicists Luis and Walter Álvarez led to the disappearance of dinosaurs – has formed a large deposit of copper, diamonds, zircons, etc.
The development of human beings is destined to leave the cradle of the earth, and the continuous expansion of civilisation involves the consumption of enormous resources. After the moon, asteroids have become the main target of development and use of human space resources, which should necessarily be the “strategic” energies of future humans. According to the type of emission spectrum, scientists divide asteroids into the following types: C, M and S.
C-type (carbonaceous) asteroids are the most common variety, accounting for about 75 per cent of known asteroids. They are rich in volatiles and are distinguished by a low albedo (ratio of reflected light from a celestial body to incident light), as their composition includes a large amount of carbon, as well as rocks and minerals. Their density averages about 1.7 g/cm3. They are found most frequently at the outer edge of the asteroid belt, 3.5 astronomical units (AUs) from the sun, where 80 per cent of asteroids are of this type, while only 40 per cent of asteroids 2 AUs from the sun are C-types (one AU is equal to the distance between the sun and the earth). The proportion of C-types may actually be higher than this, because C-types are much darker (and therefore less detectable) than most other types of asteroids, with the exception of other types that are mainly found at the outer edge of the asteroid belt.
M-type asteroids are a spectral class of asteroids that appear to contain higher concentrations of metallic phases (e.g. iron-nickel) than other classes of asteroids, and are widely believed to be the source of iron meteorites.
S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition – hence their name. They have a relatively high density. About 17% of asteroids are of this type, making it the second most common type after C-type. For example, asteroid No. 16 Psyche – discovered on 17 March 1852 by Annibale de Gasparis from the Capodimonte Astronomical Observatory in Naples – has a diameter of about 250 kilometres. Some scientists estimate that it contains five hundred million tonnes of iron, five trillion tonnes of nickel and hundreds of millions of tonnes of other rare metals, including gold.
If humans were to drag this asteroid close to the moon for mining operations and bring useful metals back to earth, the value of its resources would be very considerable and it could also be used as raw material for the in-situ construction of manned exploration vehicles. It would play an important role and also provide an important stepping stone for humans to make journeys into deep space. It has therefore become a major focus of human space resource development and use.
There are plans to reach asteroid 16 Psyche. The mission was approved by NASA on 4 January 2017 and was originally scheduled for launch in October 2023, with an earth gravity-assist manoeuvre in 2024, a flyover of Mars in 2025 and landing on the asteroid in 2030. In May 2017, the launch date was brought forward to aim for a more efficient trajectory, with launch in 2022, with a Mars gravity assist in 2023 and landing in 2026. On 28 February 2020, NASA awarded SpaceX a $117 million contract to launch the Psyche spacecraft and two smallsat secondary missions on a Falcon Heavy rocket. In October 2022, it was decided that the mission should be launched no earlier than October 2023, reaching the asteroid in August 2029. The distance of asteroid 16 Psyche from earth is 376,217,445 kilometres (2.514858 astronomical units).
Asteroids basically have a weak gravity and no atmospheric environment. As technology continues to develop, it is possible to perform multiple surveys at low cost and even bring back samples. These exploration activities will also play a huge role in human deep space exploration technology, including electric propulsion, precise orbit control, autonomous navigation and deep space communication.
All this is nothing more than an alternative to the last remaining resources on planet Earth, as a scramble for outer space is highly desirable and certainly not wars by the most powerful countries to raid and plunder the last riches in the territories of the weakest ones.
Hence the development of space mining designs is no longer just a science fiction chapter written by Jules Verne or contemporary authors, as space technology enabling humans to land on asteroids and recover raw materials has been demonstrated in terms of possibilities, especially with the aid of artificial intelligence and robotically humanoid crews or simply excavators and grippers.
Back in January 2016, the website of the magazine Wired published the article Space Mining May Trigger Star Wars, in which some experts predicted that space mining could be one of the most profitable and beneficial industries for mankind in the next half of the 21st century. Hence, what treasures exist on asteroids and which countries and companies are currently eager to try mining them?
Today, some metal raw materials on earth are scarce or overexploited, and many companies cannot help but look deep into space for more resources.
According to NASA’s survey, in the asteroid belt between the orbits of Jupiter and Mars, millions of rocks of different sizes (from a thousand kilometres to a few metres in diameter) form a ring around the sun. It is a distant remnant of the formation of the solar system. Scientists have discovered that although some asteroids are small in size, they contain – as seen above – rich resources of metals, such as high-purity iron and platinum etc. They are about 40 million kilometres away from earth. Many of the rocks have left the planetary belt due to collisions and many of them have flown close to our planet.
Since there is almost no gravity on the asteroid, very powerful machines can be used so that their weight does not adversely affect them. This is also a great advantage as huge materials could be transported without excessive effort to detach them from the celestial body. Although these projects require billions of dollars in investment, they are still much cheaper than mining on the Moon or Mars.
According to media reports, the US companies Deep Space Industries and Planetary Resources have been designing spacecraft systems for at least seven years to investigate and find possible development targets. Planetary Resources is examining a series of observation satellites in space to find the most suitable asteroids for exploitation. When you land on them, you need to assemble the necessary structures and then start mineral development from there.
In terms of choice of technical solution, machinery and equipment can be powered by solar energy, which would greatly reduce the fuel needed to transport the machinery from earth to the asteroids. The number of people on board could be limited, and hence all workers, including robots, should be sufficiently light. During the mining process, each spacecraft and equipment should be firmly fixed on the asteroid to prevent them from drifting off and being lost in space due to the absence of gravity, which is a disadvantage in such a case.
According to foreign media reports, researchers at the University of Bielefeld in Germany have created a robot based on the structure of the stick insect that is able to proceed on rough and uneven terrain and cross rocky one. It can automatically search for and transport goods on difficult terrain, which would also apply to the exploration of planets and not just asteroids. The countries interested in involving asteroids for their exploitation of raw materials are the following: United States of America, People’s Republic of China, Russia, Germany, Luxembourg, United Arab Emirates and Japan, as well as the European Space Agency.
NASA has formulated a space development plan for the next twenty-five years and will launch a series of exploration missions to asteroids, such as capturing them and pulling them into an orbit in the Earth-Moon system not only for mining but also for changing dangerous trajectories.
In this regard, in October 2022, the analysis of data obtained over the last two weeks by the investigation team of NASA’s Double Asteroid Redirection Test (DART) spacecraft mission showed that the kinetic impact of the spacecraft with its asteroid target, Dimorphos, successfully altered the asteroid’s orbit. This marks the first time mankind has purposely changed the motion of a celestial object and the first large-scale demonstration of asteroid deflection technology.
NASA Administrator Bill Nelson said: “We all have a responsibility to protect our home planet. After all, it is the only one we have. This mission shows that NASA is trying to be ready for whatever the universe throws at us. This is a watershed moment for planetary defence and for all mankind, demonstrating the commitment of NASA’s outstanding team and partners from around the world”.
For this analysis, astronomers will continue to study the images of Dimorphos from DART’s terminal approach and from the Light Italian CubeSat for Imaging of Asteroids (LICIACube): the latter is a mission of the Italian Space Agency (ASI), and is part of NASA’s DART mission. The DART team is continuing to work on this rich database to fully understand this first planetary defence test of asteroid deflection.
Giancarlo Elia Valori