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"The Shenzhou-15 return capsule has landed at the predetermined location, and the astronauts are in good physical condition and can carry the astronauts back to the ground together."
The return capsule of Shenzhou-15 carrying three astronauts landed smoothly at the Jiuquan Satellite Launch Center in Inner Mongolia, which was the first space mission in the history of Chinese astronauts in which three astronauts flew on the same stage.
The three astronauts Wang Yaping, Zhou Wangxin and Nie Haisheng left the Tiangong core module first to return to Earth, and according to the pictures taken by reporters at the scene, when the three astronauts were carried out by the staff from the return capsule, they seemed to have inflexible legs and feet and could not stand on their own, what is going on?
Astronauts have been in space for a long time, why is this happening?
1. The effect of microgravity on the body.
After an astronaut takes a long space flight in space, there are many symptoms in the body, the most common ones are vomiting, dizziness, etc., but these symptoms appear in the process of returning to Earth, so what about in space?
Are there any symptoms that have always accompanied the astronauts?
In fact, it is the symptoms that accompany these astronauts all the time that make astronauts have symptoms of "unable to stand" when they return to Earth.
Microgravity means that the force of the object is less than 1 g, and the weight of the object in this state is almost negligible, so as to give people the feeling that the weight of the object is equal to 0, which is the feeling of "weightlessness", and astronauts live in this state of microgravity for a long time in space.
Since the weight of the object is equal to 0, astronauts can easily move and control their bodies in space, can levitate freely in space, and can even move quickly, and there will be no resistance, which makes it very convenient for astronauts to carry out various experiments in space.
But microgravity also has its adverse effects, because astronauts are always in microgravity in space, so the body can not withstand the normal load and pressure from the earth, which makes the astronaut's body very "fragile".
The first is the skeletal system, which is composed of bones and skeletal muscles, and bones are formed by calcium salts deposited on collagen fibers, which can bring very high hardness and toughness to the bones, making the bones very strong.
However, because the astronaut's bones cannot withstand normal pressure for a long time, the calcium salt of the bones will be decomposed, so that the bones lose their original strength and quality and become more fragile, so astronauts are prone to bone diseases such as fractures and bone density reduction in space.
Muscle tissue is also affected in a similar way, due to the lack of normal load for a long time, muscle tissue will lose its original strength and quality, become weaker, and even muscle atrophy will occur.
In addition, because the astronaut's body is in a slightly heavy state for a long time, the blood of the lower limbs will gradually flow to the upper body, which will eventually lead to a very large impact on the blood circulation of the lower limbs, which makes the astronauts' lower limbs prone to varicose veins and other diseases.
At the same time, astronauts' heart and respiratory systems and other physiological systems will be affected by lack of exercise, and even the immune system will decline, which brings great hidden dangers to the health of astronauts.
Second, the challenge of returning to Earth.
Because the astronaut's body in space will have the above symptoms, so when the astronaut returns to the earth, he needs to go through the process of deorbiting, re-entering the atmosphere, landing and other processes with high load and high stress, which requires the astronaut to have very good physical and psychological quality.
First of all, the de-orbit stage is the process of astronauts exiting the orbit and orbiting the earth's flight trajectory, because Shenzhou 15 and the Tiangong core module are combined flights, so the Shenzhou 15 return module must first be separated from the Tiangong core module, and then adjust its orbit and carry out deorbit operations.
The de-orbit operation is very dangerous, because if it is not done properly, it will allow the Shenzhou-15 return capsule to come into contact with the atmosphere, which will cause the re-entry capsule to burn and explode, thus endangering the safety of astronauts.
Therefore, it is necessary to carry out the deorbit operation at an appropriate altitude, and at the same time to predict the density of the atmosphere, and arrange the appropriate time period according to the quality and shape design of the return capsule, which requires the astronaut's spatial sense and prediction ability to be very high, but also needs to be very calm and steady, and no mistakes are allowed.
Once the deorbit operation is completed, the re-entry capsule will gradually de-orbit, and before entering the atmosphere, it will first usher in the high-temperature plasma layer, and when entering the plasma layer, the re-entry capsule will be affected by very high temperatures, and will be affected by the friction of the plasma, and the speed will gradually slow down.
At the same time, because the plasma is very rare, in this process, the temperature outside the cabin will be very high, and the temperature inside the cabin will be very low, which will cause a very serious temperature difference in the cabin, which will have a very large impact on the cabin and the astronauts.
Because plasma is made of ions and electrons, and has a very strong conductive ability, they will discharge the space capsule, and these discharge phenomena will cause static electricity, which will discharge the astronaut, which will endanger the safety of the astronaut.
Therefore, the capsule must be electrically protected to avoid these problems, so astronauts must install corresponding electromagnetic coupling devices in front of the capsule to ensure the normal operation of the electronic equipment in the capsule.
3. Examination and quarantine before returning to Earth.
When the re-entry capsule gradually passes through the plasma layer and enters the atmosphere, it will be dragged by the atmosphere, so that the speed of the re-entry capsule will continue to slow down, and finally it will enter the predetermined landing orbit, and then it will deploy the parachute and slow down to the ground.
In this process, on the one hand, astronauts must complete a series of operations such as deorbiting, entering the atmosphere, and landing in a very short time, so they need to have a very high sense of space and prediction ability, and also need a very high level of professionalism, which is a very big test for the psychological quality of astronauts.
On the other hand, in the process of returning to the atmosphere, the temperature in the astronaut's cabin will produce a very large temperature difference due to the friction of the plasma, and if there is no certain electromagnetic protection device, the equipment in the cabin and the astronauts will be electrocuted, so the astronauts must be very calm and steady, and no mistakes are allowed.
At the same time, because astronauts stay in space for a long time, there will be many aspects of the body, and if these conditions are not known, it will also bring great danger to the astronauts' return to Earth.
4. Isolation and rehabilitation.
In addition, because astronauts stay in space for a long time, astronauts may have a variety of microorganisms in their bodies, and these microorganisms are affected by the extreme environment in space and are likely to mutate, posing a very big threat to astronauts and spacecraft.
Therefore, before returning to Earth, it is necessary to conduct a comprehensive physical examination and microbial testing of astronauts to help scientists understand the physical condition of astronauts and the microorganisms in their bodies, so that corresponding treatment plans and isolation plans can be formulated to ensure the safety of astronauts.
Once on Earth, astronauts need to undergo a series of rehabilitation exercises and medical examinations to adapt to the Earth's gravity environment and restore normal body functions.
At the same time, there are also many scientists in China who are studying the physical condition of astronauts, and through scientific rehabilitation plans and treatment methods, astronauts can gradually restore the normal functions of their bodies.
epilogue
With the development of space technology, future space missions will become more complex and long-term, so space organizations need to continuously study and improve health and safety measures to ensure the health and safety of astronauts.
At the same time, the study of microbes in space is also a very important field, and understanding the mutation and adaptability of microorganisms in extreme environments can help maintain the health of astronauts and spacecraft.
Therefore, in future space missions, the importance of isolation and rehabilitation programs is not only reflected in the physical recovery of astronauts, but also in order to reduce the risk of possible virus transmission and protect the health of other humans on Earth.
By studying the physical recovery of astronauts, it can provide an important reference for the planning of long-term space missions in the future and the health management of astronauts.