What exactly does space flight mean?

Space flight is also called space flight or space travel. "Aerospace" refers to the navigation activities of spacecraft in space outside the earth's atmosphere (including the solar system), which can be roughly divided into manned space flight and unmanned space flight. "Aerospace", a new thing in the long river of human history, uses many terms involving basic concepts, which is very different from "aviation".

High Life

The cosmic environment is extremely harsh, and the main factors harmful to human body are high vacuum, high hypoxia, cosmic radiation, temperature difference and so on. These unfavorable factors will cause serious harm to the human body. In this environment, astronauts cannot live and work. Facing the severe space environment, how to ensure the life safety of astronauts? Our scientists and technicians have developed a closed environment that is basically isolated from the outside world, that is, a closed cockpit, to protect astronauts.

One is in the morning and the other is in the evening.

People's long-term living habit is to "work at sunrise and rest at sunset", and sleep is usually arranged at night. The day and night cycle of spacecraft in space flight is different from our day and night cycle on earth. A day on earth is sunset and sunrise, which is set to 24 hours. A sunset and a sunrise in space flight have different periods, because it is related to the orbit of spacecraft around the earth. High orbit and long day and night cycle; When the orbit is low, the cycle of day and night is short. During the space flight of spacecraft, the duration of day and night is inconsistent. The duration of the day is long, and the duration of the night is short. The day and night cycle is 90 minutes, and the longest night is only 37 minutes. When a spaceship enters the dark side from the front of the earth, it is like entering dusk and night from day. The space shuttle is very fast. When the sun comes out, it jumps out like thunder, and when it goes down, it disappears like a whirlwind.

An astronaut once described a day in the universe: in the morning, a computer-controlled clock woke us up. Wake up, open the curtains and look at the space. The sun is shining and the sky is beautiful. But after a while, the sun disappeared, the sky darkened and night came. We think it's time to go to bed again. It's really interesting, one is in the morning and the other is in the evening. ...

Sleeping standing is the same as sleeping lying down.

The most special thing in space is sleeping position. When the body is completely relaxed in weightlessness, it will naturally form a bow posture. Aerospace experts believe that it is much more comfortable to sleep in space with a slight bow than to lie flat completely straight.

When astronauts fly in space, sleeping bags are usually fixed on the bulkhead of the spacecraft. If not, the attitude inside the spacecraft may collide with the bulkhead when the engine is started. Therefore, astronauts generally prefer to sleep with sleeping bags close to the bulkhead, which is as comfortable as sleeping in a bed. In weightlessness, you can't tell up and down. Sleeping standing is the same as sleeping lying down. So astronauts can sleep against the ceiling, or they can sleep upright against the wall, and sleep as they want.

Because people float in weightlessness, astronauts will find it difficult and inconvenient to move, and their movements are not as coordinated as on the ground. If you sit unsteadily and stagger, you may make a big turn as soon as you look up and lean back, and you may tumble when you bend over, so you should be careful in all actions.

Astronauts can overlook the earth in space flight, which is also a great pleasure of their space life. Since ancient times, flying into space has been the best daydream of mankind. The earth seen by astronauts on the spaceship is very beautiful. It is a green sphere. Look carefully during the day, most of the earth is light blue, and the dense forest belt looks bluer. The only real green belt is the Qinghai-Tibet Plateau in China. Some alpine lakes look bright and bright green, like the color of copper sulfate areas. In areas where the temperature is very low and there are no clouds, such as high mountains like the Himalayas in China, we can clearly see the landform there. The most dazzling spectacle that astronauts can see is the Kavil Salt Desert in Iran. This desert looks like Jupiter, with a red, brown and white whirlpool in the middle. This is because of the dazzling traces left by the evaporation of salt lakes from generation to generation. It sparkles like jade.

Physical exercise is essential.

Astronauts can't live in space without physical exercise. In addition to enhancing physical fitness, it also has its special significance: enhancing the adaptability to weightlessness and other space environments, and reducing the harmful effects of harsh environment on astronauts in space flight. In the long-term space station, there is a "small stadium" specially designed for astronauts to exercise, and some special space sports equipment is also set up for astronauts to use. These devices include bicycle dynamometer, miniature track, spring tensioner and negative pressure cylinder.

Astronauts who travel in space, like people on earth, need personal cleaning and hygiene treatment, such as brushing teeth, washing face, taking a bath and urinating. Dealing with sanitation and garbage under weightlessness is very complicated and requires special facilities and skills.

When you brush your teeth in weightlessness, toothpaste foam is easy to float, and water droplets will float in the cabin, which will affect people's health and the normal work of the instrument. Astronauts in the spaceship can't bring tools and methods to brush their teeth on the ground. In that case, water may float if it leaks out at a certain point, so astronauts can only brush their teeth in a simpler way. The United States uses a special kind of rubber candy, which allows astronauts to chew fully instead of brushing their teeth to achieve the purpose of cleaning their teeth. When an astronaut washes his face, he actually scrubs his face with a wet towel soaked in cleaning solution. Then, put a towel on the massage brush to comb your hair.

Astronauts need to take a bath if they live in the space station for a long time. The long-term manned space station is equipped with space bathroom facilities designed and manufactured by aerospace engineers and technicians. This bathroom is nothing more than a powerful nylon cloth shower cover. There are fixed frames above and below the shower cover, and the ceiling is connected with the floor, which becomes a closed shower cover, which is usually folded and fixed on the ceiling of the living room. The ceiling is also provided with a circular water tank, a nozzle, an electric heater, a water tank for bathing and a pipeline communicated with the large water tank.

Before bathing, prepare the purification adsorbent in the wastewater recovery and purification device, recover and purify the sewage during bathing, then clean the water supply pipeline, pumping device, filtering and purification device (to remove impurities and odor), put down the nylon cover rolled on the ceiling, and fix it directly to the bottom frame to form a drum connected to the ceiling floor, just like a completely transparent glass jar. Start the electric heater to heat the water in the water tank to a suitable temperature, then people can take off their clothes and enter the bathroom. There is a pair of fixed slippers under the cylinder, so that people will not float after wearing them. You should wear a respirator before turning on the tap. The respirator is connected with a hose leading to the outside. Astronauts can breathe the air in the cabin to avoid the danger that the mixture of air and water vapor is inhaled into the respiratory tract during bathing. Astronauts cover their ears and wear goggles when taking a shower, just like divers. After everything is ready, you can turn on the faucet, and a thin stream of water sprays on your body, forming a water film with countless bubbles on it. You must suck up the water with a towel or a suction brush. Water will not automatically flow out under weightlessness, and when there is air in the water tank under pressure, water will flow out continuously.

The disposal of astronauts' urine on the spacecraft is also quite scientific. The urinal is specially made, and the toilet is connected with a plastic sleeve. Close the rubber valve quickly after defecation, and the feces will fall into the breathable feces collection bag through the airflow, and then be sealed with a sealing bag and put into the toilet. When it is full, it will automatically pop out of the cabin.

This is the special life of astronauts. Isn't it really wonderful?

Space flight: refers to the space flight of artificial earth satellites and spacecraft near the earth or in the solar system.

With the rapid development of science and technology, reference books always seem to be old or vague and inaccurate. Although there are some local modifications that follow the development of the situation, they often lead to contradictions.

In modern natural science, the "universe" adopts the above second explanation. Generally speaking, the universe is the sum of space and time. Our ancestors had a correct understanding of the universe for a long time. The ancient book of Han Dynasty, Huai Nan Qi Customs Xun, said that "the four directions called the universe, and the past called the universe". Zhang Heng, a famous astronomer in Han Dynasty, said: "The universe is infinite, and the universe is infinite." .

With the development of science and technology, the division of space and time is becoming more and more accurate.

In ancient times when productivity was low, it was enough for people to divide time into days, months and days. Later, in order to distinguish between hours and hours. The rise of modern industries and means of transportation, such as trains, automobiles and airplanes, further requires the division of minutes and seconds. For modern technology, this is not enough. It takes milliseconds, microseconds and nanoseconds to measure time.

The same is true of the division of space. In ancient times, the concepts of heaven, air and earth were enough, but they were far from meeting the requirements of modern science and technology. Especially after the birth of space technology, it is required to strictly distinguish between "sky" and "space". "sky" refers to the vast space outside the earth's atmosphere. This is roughly equivalent to "sky" and "space". Say "roughly" because if the sun, moon and stars do not include the earth and the sky only exists outside the earth's atmosphere, then the sky is space, and the space is generally called "extremely high sky", and there is no accurate division of physical properties.

"Empty" refers to the atmospheric space above the earth's surface.

According to the above classification, are weather, weather forecast and starry sky all known as "air", "air forecast" and "starry sky"? But there is a conventional problem here, which does not need to be revised and will not cause ambiguity. Similarly, the term "space science (technology)" now used should also be called "space science (technology)". If the term "space" is too vague, it needs to be rebuilt.