Previous space missions didn't last long, maybe a few days or half a month, so the spacecraft would have its own oxygen supply and a backup system. How to solve the oxygen problem after staying in space for a long time After the development and improvement of the space station, the space station is now equipped with a relatively complete oxygen supply system.
There are three ways to make oxygen at present. The first way is to electrolyze water, which is the main way to make oxygen on the International Space Station. Water can electrolyze oxygen. Although water in space is scarce, it can be recycled. As we said before, space toilets can filter and reuse used water, such as sweat and urine, and then convert it into daily drinking water after filtration and purification.
When current flows from one positively charged electrode (anode) to the other negatively charged electrode (cathode) through water containing a small amount of salt, the two parts are separated and recombined into hydrogen and oxygen after electrification. There is oxygen-making equipment on the space station. The energy comes from solar panels, and the generated oxygen is discharged into the cabin of the International Space Station. In the early days of Tiangong-1 and Mir, China also used electrolyzed water to produce oxygen.
Second, when the spacecraft is launched, it carries a high-pressure oxygen bottle into space, and the oxygen bottle carries oxygen. The third type is solid fuel oxygen generator, also called oxygen candle or chlorate candle, which is a standby system for producing oxygen through chemical reaction. It uses chemicals such as alkali metal peroxide to release oxygen and absorb the emitted carbon dioxide. Generally, this method is only used when the solar panel fails.
At present, the oxygen used in China's Shenzhou is produced by the nitrogen and oxygen station established and manufactured by Hangyang Cryogenic Liquefaction Company. From Shenzhou-1 to Shenzhou-13, the nitrogen and oxygen station has been providing oxygen for astronauts. Astronauts have higher requirements for oxygen, and there are many air particles on the earth, which are not suitable for astronauts to use directly, so in space, astronauts use mixed oxygen with very low moisture.
Mixed oxygen is produced by the nitrogen and oxygen station of Hangyang Company, and it is the gas source guarantee unit of special gases such as liquid nitrogen, liquid oxygen and high-purity oxygen. The production of oxygen and nitrogen is a very delicate and complicated process. Because it is invisible and intangible, it is very important to control the air composition. After purification and compression, impurities such as carbon dioxide and water are removed, and then liquid oxygen and liquid nitrogen are separated through separation, condensation and distillation.
Due to the influence of weightlessness, astronauts' muscles will contract and stay in weightlessness for a long time. Without the restraint of gravity, their muscles and bones will be idle for a long time. If it is not used for a long time, it will gradually shrink and will not stand for the first time after returning to earth. In addition, osteoporosis is serious. Generally, the bone loss of the elderly is the fastest, about 1%-2%, while the astronauts who stayed in space for three months lost 6% of their bones, which is very harmful to their bones and takes at least three years to recover.
The body will also temporarily become taller. 20 17 Japanese astronaut Kimi Xuanmao said that he grew 2 cm in space in about 3 weeks. What is the reason? According to astronaut Wang Yaping, the human body will grow taller in space because the compression of vertebrae on intervertebral discs disappears. Without the influence of gravity, the cartilage between vertebrae will slowly spread out, so it will grow taller temporarily, and generally it will return to its original height within one week.
In addition, the round heart, bigger face, decreased blood and decreased vision are all physical changes that astronauts will face after returning to the ground. It is understood that aerospace medical experts are also establishing a mathematical simulation model of human motion under weightlessness. In order to reduce the impact of space environment on astronauts' bodies, we hope to better ensure the safety and health of astronauts in space.
Ok, that's all for today. Pay attention to passers-by and listen to them. See you next time.
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