China’s Chang’E-5 lunar robotic mission has identified more than water on the surface of the Moon. Researchers have indeed confirmed the discovery of a new mineral, a transparent crystal named Changesite-(Y). The mission also spotted helium-3, a potentially promising fusion fuel.
A new lunar mineral
Just over two years ago, China landed on the moon as part of its Chang’e 5 mission before bringing nearly two kilograms of rock back to Earth a few weeks later. On site, analysis of the reflectance spectra of the area surrounding the landing site had identified the presence of water at an average of 120 parts per million. It was then the whole first detection of water on the Moon in situ.
More recently, the analysis of the samples collected led to the discovery of a new mineral. The International Mineralogical Association confirmed the results. It is the sixth mineral ever identified on the Moon. The latter, named Changesite-(Y), is represented by a monocrystalline particle with a radius of about ten microns.
” Changesite-(Y) is a kind of colorless transparent columnar crystal“, details the Chinese press agency Xinhua. ” It was discovered from an analysis of lunar basalt particles by a research team from the Beijing Research Institute of Uranium Geology, a subsidiary National Nuclear Society.”
The researchers also determined the concentration of helium-3 (figures not given) in their samples, and succeeded in deducing the “extraction parameters” necessary in order to harvest this isotope from returned samples.
Is helium-3 really worth it?
Helium-3 – the only known stable isotope containing more protons than neutrons (2:1) – is considered a promising potential fuel for nuclear fusion. In theory a deuterium/helium-3 fusion reaction could release 164.3 megawatts of energy per gram of helium-3, all without producing radioactivity.
On Earth, the helium-3 approach nevertheless poses a number of problems.
On the one hand, because a fusion involving this element could only take place at much higher temperatures than those necessary in a tritium reactor for example (several hundred million degrees).
On the other hand, helium-3 is extremely rare and difficult to isolate on Earth. The main way to obtain it is to wait for the tritium from nuclear warheads and other associated stockpiles to decay, then collect it in small quantities. It does occur naturally in the Earth’s atmosphere, but in tiny concentrations (7.2 parts per trillion).
The surface of the Moon, on the other hand, could contain up to 1.1 million metric tons of helium-3. However, the costs associated with operating it would be astronomical. Indeed, the highest estimated concentrations of helium-3 in the lunar soil would be around fifty parts per billion. So you would probably have to process 150 tons of regolith to harvest just one gram. You would then need to bring it back to Earth.
Nevertheless, the extraction of lunar helium remains an option for China.
Finally, in addition to the Changesite-(Y) and Helium-3 announcements, the National Space Administration of China also announced full state approval for the next three Phase 4 lunar missions. Chang ‘e 6, 7 and 8 will therefore lay the foundations of the future Chinese Lunar Research Station.