Basic principles of Asteroid mining

What is asteroid?

Asteroid is a relatively small celestial body of the Solar System moving in an orbit around the Sun. Asteroids are much smaller in mass and size than planets, they have an irregular shape and do not have an atmosphere, but they can have satellites too. Currently, hundreds of thousands of asteroids have been discovered in the solar system.

Classification 

Three quarters of known asteroids are classified in this way:

Group of carbonaceous asteroids (C-type) - includes dark carbon asteroids with low reflectivity. This group includes 75% of the total number of asteroids. 

Group of silicaceous asteroids (S-type) - includes stone asteroids. This group includes 17% of the total number of asteroids.

Group of iron asteroids (X-type) - collects together several types with similar spectra, but quite different compositions. This group includes objects with a high iron content. This is the third most widespread group of asteroids. 

There are also several smaller classes. 

However, despite the predominance of the C-type, most near-Earth asteroids belong to the S-type, they are reddish-red stone bodies which occupy a dominant position in the inner belt of asteroids.

Resources 

Various minerals and volatile elements, which compound asteroids, can be the source of iron, nickel and titanium. In addition, it is assumed that some asteroids contain hydrous minerals consisting of oxygen and water needed to sustain life, and hydrogen which is one of the main types of propellant fuel. In further exploration of space, the use of space resources will be indispensable.

Metals

At a sufficient level of development of the technology of exploitation of raw materials such as platinum, cobalt and other rare minerals from asteroids with subsequent transportation them to the Earth, it may be profitable. In prices of 1997 year, a relatively small iron asteroid 1.5 km in diameter contained a variety of metals, including precious metals worth 20 trillion USA dollars.

In fact, all the gold, platinum, iron, cobalt, manganese, palladium, rhodium and other metals that are now mined from the upper layers of the Earth are the remnants of asteroids that fell during the early meteoric bombing, when, after the cooling of the crust, the great amount of asteroid material rained down on Earth. Due to large mass, more than 4 billion years ago the differentiation of mineral resources took place, and as a result, the majority of the heavy elements fell to the core of the planet under pressure of the gravity. And on asteroids, there has never been a differentiation of the mineral resources and all the chemical elements are spaced equally.

The World Community 

From 21st to 22nd of September 2016, a conference with scientists, studying the asteroids science, and with business men who wanted to learn a new type of business was held; all the needed conditions were created for a detailed discussion of the specific properties of asteroids and the engineering needs of space missions. "Asteroid mining is an incredible intersection of science, engineering, business and imagination," says Galache from Aten engineering enterprise. In a written press release of this conference, issues, related to the need to conduct a survey of asteroids in preparation for mining operations on the surface and in the deep areas of asteroids, are considered. Also, great attention should be paid to the implications of astrobiology and the protection of our planet, and of course to other questions concerning the policy and strategy of developing a roadmap for resources transportation. 

Lack of Knowledge

The World Conference has borne fruits - knowledge gaps have been identified: miners need access to a map of nearby asteroids, with atmosphere similar to the Earth’s, so they can consider potential targets. Many objects are still not explored, or our knowledge about them is not enough, therefore, it is also necessary to develop the detection of near-Earth asteroids and follow the program. Galache explains: "Near-Earth asteroids are detected by their brightness, our best chance to study them is in a short time using powerful telescopes to detect an asteroid and describe its shape and spectral characteristics, and for this purpose we need high-quality, specialized telescopes, but for now we do not have access to such equipment ".

Further research is essential to understand the connection between asteroids and meteorites, as well as to obtain information in order to create imitation asteroid soils or "regolith" and to work out practical aspects of the mining mission, such as planting and retrieving materials. There are two methods to study the composition of the asteroid, the first is to analyze light reflected from the asteroid surface, the second is to study fragments landed on the Earth in the form of meteorites. Both methods have its limitations.

Spectral observations emanate from the upper layer of the asteroid, which was battered in space and subjected to other processing methods. Meteorites are extremely important, but they have no part of history: fragile components of primitive material contained in asteroids will be lost in atmospheric entry. At the moment, comparison of the meteorites types back to different parent asteroid classes is not reliable. The shortest way to understand the structure of near-Earth asteroids is to define the source of their formation in solar system and to look at the characteristics of their "Orbital family". Thus, another knowledge gap is the connection between dynamic predictions, where near-Earth asteroids originate from their actual physical characteristics.

Technologies

It is necessary to put in a lot of effort to understand the dynamics of granular material, in conditions of low gravity. Studies show that the granular material can behave as a solid, liquid or gas. In this environment, this behavior will be especially important for asteroids, which are debris, since a spacecraft trying to land or drill them can easily destabilize regolith causing a granular flow or avalanches.

It is essential to adapt technologies which allow to mine fossils from asteroids, to low gravity environment. Possible solutions include: abolishing reaction forces by digging simultaneously in opposite directions or tying a net around an asteroid to capture in the process of digging.

Few Words in Conclusion

Exploitation of raw materials from asteroids, which are used as fuel, building materials or for life support systems can radically change the study of our Solar System. Such ambitious projects are a challenge not only for a specific group of scientists, but for humanity. I will be incredibly happy if one of you will get at least a little closer to the implementation of such a high-level project.