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On December 16, 2020, a capsule containing samples of lunar soil, taken by the Chinese probe Chang’e 5, landed in Inner Mongolia. These samples have been carefully examined by scientists. The China Space Administration and the China Atomic Energy Authority have just announced the discovery of a brand new mineral, which they call Changesite-(Y). This is the first time that China has discovered a new mineral on our satellite.
Thanks to the Chang’e 5 mission, China has become the third country (after the United States and the former Soviet Union) to bring lunar samples back to Earth. No lunar material had been reported since 1976! It is therefore with interest and great meticulousness that the Chinese scientists analyzed the approximately 1700 grams of regolith collected in the Mons Rümker region. They announce today that they have detected a new mineral — the sixth discovered on the Moon.
According to the Xinhua News Agency, this new mineral is a kind of transparent and colorless columnar crystal. It was discovered from an analysis of lunar basalt particles by a research team from the Beijing Uranium Geology Research Institute, a subsidiary of the China National Nuclear Corporation. The discovery makes China the third country in the world to have discovered a new mineral on the moon, said Dong Baotong, deputy director of China’s Atomic Energy Authority.
One more step towards the exploitation of lunar helium 3
Changesite-(Y), present in the sample as a single particle with a radius of approximately 10 micrometers, has been officially approved as a new mineral by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association.
But the Chang’e 5 mission made it possible to obtain another crucial data: the samples made it possible to estimate the concentration of helium 3 contained in the lunar dust and to define its extraction parameters. However, helium 3 is a promising potential fuel for nuclear fusion. The “preferred” nuclear fusion reaction is normally initiated with two isotopes of hydrogen, deuterium and tritium. The latter has one proton and two neutrons; it decays into helium 3, emitting low-energy beta radiation and an electron antineutrino.
The helium-3 nucleus has two protons and a single neutron (it is the only known stable isotope of an element that has more protons than neutrons). A fusion reaction between deuterium and helium 3 produces helium 4 and a proton; it can theoretically release 164.3 megawatt-hours of energy per gram of helium 3, precise New Atlas. The advantage of this reaction is that neither the helium 3 nor the products of the reaction are radioactive (unlike the deuterium-tritium reaction, where the neutrons produced can make the materials in the reactor radioactive).
If this reaction is not currently considered by experimental fusion reactors, it is because it requires even higher temperatures than a tritium reactor (about 600 million degrees!), not to mention that the helium 3 is extremely rare and difficult to isolate on Earth (in the atmosphere, it is present in minute concentrations of the order of 7 parts per trillion). Helium 3 today comes mainly from the disintegration of tritium, which itself is produced in a nuclear fission reactor. On the Moon, on the other hand, it is much more abundant: according to estimates, the lunar reserves of helium 3 would amount to 1.1 million metric tons.
A precious resource, but difficult to exploit
According to’International Policy Digest, this represents resources worth around 1.5 quadrillion dollars (not counting the price increase inherent in the use of helium 3 in future fusion reactors)! For Ouyang Ziyuan, head of China’s lunar exploration program, these resources are “a transformational fusion energy opportunity”: Each year, three space shuttle missions could provide enough fuel for all humans on the planet “, he said in the mid-2000s.
An interesting resource, but the construction of a lunar mining facility would generate considerable costs, not to mention the organization of the return to Earth of the helium 3 harvested… The highest concentrations of helium 3 in the lunar soil are estimated at approximately 50 parts per billion, it would therefore be necessary to process 150 tons of regolith to harvest a single gram of this isotope! Note that China has not communicated the exact concentrations found in its samples.
The costs of extracting the precious isotope do not seem to curb the ambitions of China, which is firmly determined to position itself in the sector as soon as possible. As pointed out by theInternational Policy Digest, it is the only one to map helium-3 deposits on the far side of the Moon. ” If China were to obtain the monopoly of helium 3 available on the Moon, it would become the first economic power on Earth “, sums up the magazine.
After the announcement of the discovery, the Chinese Space Agency has also confirmed the next three lunar missions of the Chang’e exploration program in the next 10 years. The Chang’e 6 mission, whose launch is scheduled for 2024, must recover samples from the far side of the Moon; the following missions will be used to explore the lunar south pole and to lay the foundations of an international lunar research station.