Earlier, according to foreign media reports, the United States issued a document entitled "International Support Guarantee for the Exploitation and Use of Space Resources", which formally established policies for the future entry of the United States into space, especially for the exploration of space resources on the moon and asteroids.
Although this document has caused countless controversies, it is undeniable that the exploitation of resources in outer space is very tempting. It is understood that asteroids are rich in carbon, sulfur, nitrogen, and hydrogen, which can provide humans with abundant raw materials and fuels after mining. In addition, some scarce resources on the earth, such as platinum-based metals and palladium metals, are also widely distributed in outer space.
So, if the earth encounters a bottleneck of mineral resources, can space become a human resource supply station? What obstacles do humans need to overcome in order to conduct space mining? Recently, Zhang Kefei, a specially-appointed professor at China University of Mining and Technology, answered these questions when sharing research progress.
Near-Earth asteroids are currently the most suitable for mining
"In the next 100 years, human beings must leave the earth for survival and go to space to find new homes." This prediction by the English physicist Hawking in 2017 may become a reality.
According to Zhang Kefei, oil, natural gas and coal are the three pillars of world energy supply and consumption, accounting for more than 85% of primary energy consumption. According to the 2019 World Energy Statistics Yearbook, the three types of energy reserves are only sufficient for 50 years. , 50.9 years and 132 years of global consumption.
At the same time, according to the prediction of the United Nations Population Fund, the annual increase in the global population will remain above 86 million. By 2050, the world’s population will reach 9.8 billion, and the energy demand will be increasing.
In order to solve the bottleneck of the depletion of the earth's mineral resources and the sustainable development of the human community, the development and utilization of abundant space resources is imperative, and space mining has emerged.
Near-Earth asteroids refer to those asteroids whose orbits intersect Earth's orbits. Previously, according to foreign media, the National Aeronautics and Space Administration (NASA) tracked approximately 16,700 near-Earth asteroids. The water, silicon, nickel, and iron on these asteroids are the development priorities. After the water is decomposed into hydrogen and oxygen, it can be used as a power fuel to fill the aircraft, which is clean and low cost; silicon can be used to develop solar systems; nickel and iron are potential resources for space manufacturing.
According to Zhang Kefei, asteroids can be divided into C (carbon) asteroids, S (silicon) asteroids, and M (metallic) asteroids according to their spectral characteristics. Among them, the C and M asteroids are considered to contain huge mineral resources and economic value, which can be used by humans. Specifically, Class C asteroids are rich in carbon, hydrogen, oxygen, nitrogen and other elements, which can provide fuel for deep space exploration and serve as a supply station for space exploration; Class M asteroids are mainly composed of iron and nickel, and some asteroids Platinum-based metal elements are rich in content, such as platinum, cobalt, rhodium, iridium, osmium and other rare metals.
Zhang Kefei said that the focus of space resources mining on asteroids is a comprehensive consideration of many factors.
"Considering modern science and technology, the value of resource exploitation, and the safety of the earth, the most suitable target for mining at this stage is the near-Earth asteroid, and existing studies have proven that there are more than 1,500 asteroids with very high recoverable And mining value." He said that mining mineral resources on near-Earth asteroids may also reduce the risk of some asteroids hitting the earth.
Space mining needs to overcome multiple obstacles
An article published by MIT estimated that it would cost about US$1 billion to develop a new rare earth metal mine on earth. In comparison, the cost of bringing a smaller asteroid back to Earth in the near future is comparable. However, in distant space, if you want to be a good "miner", in addition to the cost, there is a basket of problems to be solved.
"Space mining first needs to overcome the low reaction force under low/microgravity, to ensure that the equipment can achieve fully autonomous and intelligent operation on weathered dust. In addition, the mining process must also overcome the obstacles of sub-surface rocks, to solve the equipment for long-term night Work and energy storage issues." Zhang Kefei said.
In addition, Zhang Kefei also emphasized that there are also great challenges in the communication between the earth and space. If problems occur during space mining, failure to send information to the ground in time to make judgments may cause incalculable losses.
To solve these problems, spatial information technology is one of the key technologies. It is understood that at present, researchers are conducting research on issues such as space navigation and positioning, information perception, and intelligent equipment for space mining. "Human activities on the earth, especially large-scale engineering projects, are pioneers in surveying and mapping. The same is true for the exploration of the moon and Mars. We must first establish a benchmark before we can guide surveying, mining, and machinery operations." Zhang Kefei introduced that it is necessary to realize space as soon as possible. Mining also requires research on space navigation and positioning and information perception, intelligent equipment for space mining, exploration and selection of space resources, space safety and comprehensive utilization of space resources, and breakthroughs in space environment monitoring and space resources under different gravity environments. A series of technical problems, such as utilization methods, on-site processing and in-situ utilization of space resources, and rapid transportation of space resources, are expected to provide a powerful guarantee for space mining.
