What is the idea of exploring and using the moon?

The moon is the closest celestial body to the earth, and it is also the only planet except the earth with human footprints. Human research on the moon can be traced back to ancient times, when there were records and predictions about lunar eclipses. After long-term research by ancient and modern scientists, especially in the 40 years at the end of the 20th century, humans landed on the moon many times, sampled and analyzed the lunar soil, and used spacecraft to approach and detect the moon. The results prove that the moon has the basic conditions for human development and utilization.

First of all, the moon is rich in material resources. There are all the elements and more than 60 minerals on the moon, 6 of which are not found on the earth. In the soil of the moon, the content of oxygen is 40%, the content of silicon is 20%, and there are rich calcium, aluminum and iron.

Through the analysis of moon rock samples, it is found that there are mainly three types of rocks on the moon. The first is the Moon Sea Basalt rich in iron or titanium. Dark Moon Sea Basalt is mainly composed of clinopyroxene, basic plagioclase and ilmenite, sometimes containing olivine and apatite, or microsatellite sulfur iron and metallic iron. More than 20 kinds of basalt were found in the rocks retrieved from the moon landing. According to the content of titanium oxide, Guangdong basalt can be divided into high titanium, low titanium and very low titanium. These basalts are characterized by being rich in titanium and iron, not containing water minerals, low oxygen fugacity, not containing trivalent iron, and various fine-grained to coarse-grained structures. The second is plagioclase, a rock rich in potassium, rare earth and phosphorus. Plagioclase is composed of 95% plagioclase and a small amount of low calcium pyroxene, which is mainly distributed in the lunar highlands. The third type consists of a size of 0? The breccia composed of 1 ~ 1 mm debris particles is the product of impact. Breccia can be divided into broken plagioclase, partially melted breccia, complex clastic breccia and deep metamorphic extrusive rock.

According to spectral analysis, moon rocks contain all the elements in the earth's crust and about 60 kinds of minerals, among which 6 kinds of minerals are not found on the earth. Refractory elements account for about 65% of the mass of the moon, and the residual liquid rich in iron and refractory elements condenses into a 250-kilometer-thick lunar shell. In lunar soil, oxygen accounts for 40%, which is the oxygen source of propellant and life support system of controlled ecological environment; Silicon accounts for 20%, and the conductor is the raw material for making solar cell arrays. The proportions of other elements are lead 6% ~ 8%, magnesium 3% ~ 7%, and iron 5% ~1/? 3%, calcium 8% ~ 10? 3%, titanium 5% ~ 6%, sodium, potassium, manganese content in a few thousandths, zirconium, barium, scandium, niobium content in a few ten thousandths. Scientists heated the lunar soil sample to 2000 degrees Celsius and found that inert gases escaped from the lunar soil, including radioactive particles such as helium, argon, neon and xenon. The moon is also rich in helium -3, a rare energy source on earth, which is an ideal fuel for nuclear fusion reactors. A rust-free iron film was also found on the lunar rock specimen. At first, scientists speculated that this kind of iron would oxidize and rust immediately if it was placed on the earth. But the result of the experiment is that this kind of iron will not be oxidized, commonly known as "pure iron". Pure iron is very useful to human beings. It is estimated that in developed countries, the annual loss caused by metal corrosion accounts for about110 of national economic income. If pure iron can be produced on the moon and transported back to the earth for use, it will not only fill a gap, but also obtain huge economic benefits, which is undoubtedly a great contribution to mankind.

It is very attractive to develop the natural mineral deposits of the moon. Processing materials into final products for space and ground use at the lunar base is expected to be an efficient industry with attractive prospects.

Energy is one of the most serious problems facing human survival and development. There are two ways to solve the future energy shortage: solar energy and nuclear energy. The testing and analysis of lunar samples and the discovery of helium -3 have injected new stimulants into lunar research and exploration, especially attracting the attention of energy experts. However, the formation, distribution, storage and application of lunar helium -3 are still urgent problems in lunar scientific research. Only through a lot of exploration and field trips to the moon can we get a satisfactory answer.

The surface soil of the moon is composed of debris, powder, breccia and glass beads, and its structure is loose and quite soft. The soil in Yuehai area is generally 4 ~ 5 meters thick, and the soil in highland is thicker, but it is only about 10 meter. The particle size of lunar soil varies greatly, from a few centimeters to only 1 mm or dozens of microns. These fine soils are generally called moon dust. The lunar soil is mostly fine breccia and glass beads, accounting for about 70%, and small-grained basalt and gabbro account for about 13%. The content of inert gas in lunar basalt and highland breccia is extremely low, even lower in the atmosphere, almost zero. However, lunar soil and breccia are rich in airborne elements. This is due to the injection of solar wind, which is actually a stable particle stream ejected by the sun. The chemical composition of the solar wind was directly measured by the "Na Wei 3" rocket in 1965. The results show that solar wind particles are mainly composed of hydrogen ions, followed by helium ions. Due to the influence of foreign objects on the surface of the moon, lunar soil materials are mixed together, and these airborne elements exist in the range of tens of meters deep. The depth of the exposed surface of an object implanted with solar ions is usually less than 0? 2 microns. Therefore, the content of these elements is the highest in the finest particles of lunar soil, and most of the particles injected with gas accumulate and stick to the breccia of lunar soil or glass beads.

Moon rocks photographed by Apollo 17

The results show that the content of helium in lunar soil is (1 ~ 63)/ 107, and the content of helium -3 is (0? 4~ 15)/ 10 10。 Helium is mostly concentrated in ilmenite-rich lunar soil less than 50 microns, and it is estimated that the whole moon can provide 7 15000 tons of helium -3. Why people are interested in helium -3, because helium -3 is the best choice for nuclear fusion fuel in the future. Helium is produced by the fusion of deuterium and helium -3. This fusion reaction is safe, clean and easy to control. On the earth, the known helium -3 resources in natural gas deposits can only maintain the consumption of a 500 MW power plant for several months, and the electricity generated by helium -3 in lunar soil is equivalent to 40 thousand times that of the United States 1985. Considering the cost of mining, exhaust, isotope separation and transportation of lunar soil, it is estimated that the energy repayment ratio of helium -3 can reach 250. This repayment ratio is quite favorable compared with uranium -235 to produce nuclear fuel (the repayment ratio is about 20) and coal mining on the earth (the repayment ratio is about 16). In addition, about 6300 tons of hydrogen, 70 tons of nitrogen and 1 600 tons of carbon can be obtained by extracting1ton of helium -3 from lunar soil. These by-products are also necessary to maintain the permanent base of the moon.

In addition, a nuclear energy base can be established on the moon to transmit electric energy to relay satellites in geostationary orbit, and then to receiving stations on earth, and then distributed to various regions for users to use. It is not difficult to understand the far-reaching significance of returning to the moon only from the development and utilization of lunar helium -3 resources.

Scientists have been studying the method of extracting oxygen from the surface soil of the moon for a long time. They experimented with the moon sand retrieved by Apollo spacecraft. At the high temperature of 1000℃, ilmenite in lunar sand contacts with hydrogen to generate water, and then oxygen is extracted from the water by electrolysis. Research shows that it takes about 70 tons of lunar topsoil to extract 1 ton of oxygen. Considering the special situation of production on the moon, it is suggested that a set of small chemical treatment equipment should be equipped while building the lunar base, which is powered by solar energy and can produce about 100 kg of liquid oxygen every day. The specific process is that the moonstone reacts with methane at high temperature to generate carbon monoxide and hydrogen. In the second reactor with lower temperature, carbon monoxide reacts with more hydrogen and is reduced to methane and water; Then the water is condensed and electrolyzed into oxygen and hydrogen, the oxygen is stored for later use, and the hydrogen is sent to the system for recycling. It is predicted that the original intention of the lunar oxygen-making equipment is to provide oxygen for astronauts on the surface of the moon, but they don't need much oxygen. A base with a scale of 12 people only needs 350 kilograms of oxygen every month. A set of oxygen production equipment can produce a considerable amount of oxygen after continuous operation. Therefore, when building the lunar base, permanent liquid oxygen storage should be built at the same time, so as to supply the spacecraft with cryogenic propellant fuel.

Significantly, in the process of oxygen production, the "slag" obtained after chemical treatment has become a superior by-product. This is because it is rich in meltable free silicon and metal oxides. As long as appropriate industrial methods are adopted, smelting can be continued and titanium metal with great industrial value can be extracted. The technological process of titanium production proposed by scientists is to extract titanium oxide from "slag" by mechanical crushing and magnetic separation, and then hydrotreat it at a high temperature of 1273 degrees Celsius to produce titanium oxide. Then replace the iron in it with sulfuric acid, then mix it with carbon, introduce chlorine at 700 degrees Celsius, and generate titanium tetrachloride after chemical reaction. Then heating at a high temperature of 2000 DEG C, adding magnesium for dechlorination, and finally obtaining molten titanium.

The refining method of aluminum is more novel. The aluminum on the surface of the moon is composed of complex structures called plagioclase. After repeated experiments and research, scientists put forward a new aluminum smelting process. The specific method is as follows: crushing the moon rock, heating it at 1700℃ to melt it, then cooling it in water to 100% to make multi-mass balls, then crushing it, and adding sulfuric acid at 100℃ to leach aluminum. After removing silicide by centrifugal separation and filtration, it was pyrolyzed at 900 degrees Celsius to obtain a mixture of alumina and sodium sulfate. Then sodium sulfate is washed away and dried, then mixed with carbon and heated, and chlorine gas is added to react with it to generate aluminum chloride. After electrolysis, the final product-pure aluminum is obtained.

Glass is indispensable to the construction industry, so it is particularly important to produce glass on the moon. Ordinary glass consists of 7 1% ~ 73% silica, 12% ~ 14% sodium sulfate and 12% ~ 14% calcium oxide. The lunar soil contains 40% ~ 50% silicon dioxide, which is the main material for making lunar surface glass. Its refining method is relatively simple. According to the need, various trace additives are added to the lunar soil, some useless components are dissolved by sulfuric acid, then melted at 1500 ~ 1700 degrees Celsius, and then calendered and cooled, so that the lunar glass can be made.

The most exciting thing is1the data sent back by the American "lunar explorer" who launched into the sky on October 6, and there are 1998+ 100 billion tons of water ice at the two poles of the moon. Because the atmospheric pressure on the surface of the moon is less than one trillion times that of the earth, the temperature on the surface of the moon can reach 130 ~ 150 degrees Celsius where the sun shines, and it is easy to boil and evaporate for lunar liquid water whose boiling point is much lower than 100 degrees Celsius. Moreover, the moon is small in mass and weak in gravity, so it can't bind water vapor, and gaseous water escapes on the moon without leaving a trace.

However, the poles of the moon are very special. For example, at the south pole of the moon, there is an Aiuken basin with a diameter of 2500 kilometers and a depth of 13 kilometers. This basin is thought to be caused by a meteorite falling to the moon. It was dark and deep, and there was no sunshine all day. The temperature is always below-150 degrees Celsius, which makes it a hiding place for solid water ice.

So where did the water on the moon come from? Scientists believe that the moon is often hit by comets, and the water content of comets is about 30% ~ 80%, and the water content of steam at the tail of comets is as high as 90%. These external moisture evaporates when the surface of the moon is exposed to sunlight, and some water vapor condenses at the bottom of the basin with extremely low temperature at the moon's poles. Therefore, ice is not concentrated together, but mixed with dust.

Water consists of two elements, hydrogen and oxygen. In the future, the water and oxygen needed by human beings to establish a base on the moon can be used on the spot on the moon without relying on the supply of the earth. It is an attractive undertaking to develop the natural resources of the moon at the lunar base and process the raw materials into final products for use in space.

Secondly, the gravity on the moon is only 1/6 of that of the earth, and the escape speed on the moon is only 1/5 of that of the earth. Therefore, the moon's low gravity and no atmospheric environment are very conducive to the launch of spacecraft. The establishment of a human space base on the moon for assembly, maintenance and replenishment will become a transit point for human beings to fly to other planets. The lunar space base will greatly reduce the difficulty and cost of interstellar flight, and the depth and breadth of human entry into the universe will greatly increase.

Thirdly, the moon is not surrounded by the atmosphere, sound waves can't spread, and there is no radio interference from the earth on the back of the moon. Therefore, the moon is an ideal and stable scientific experimental platform without atmospheric interference, silent waves and radio waves. Of course, the low gravity and vacuum aseptic environment of the moon is an ideal place for material science and medical research and production.

In the future, with the progress of science and technology, traveling on the moon will be safer, more comfortable and cheaper. Then, traveling to the moon and immigration will become a reality. The moon will be the "sixth continent" developed by mankind.