Eating and drinking water is a common thing for people living on the earth, but in the weightless space life, the astronauts' diet has become very complicated and particularly wonderful. It can be said that astronauts' nutritional needs, food preparation and supply, and diet have certain particularity, which is very different from their diet on the ground.
Space food, like ordinary food on the ground, provides energy and nutrition for the human body. However, in order to save the space of the spacecraft and the payload when launching, the space food carried by astronauts should be as light and compact as possible. For example, nutritious dry biscuits and sausages can be soaked in water when eating to restore the taste similar to fresh food. In addition to being able to withstand the impact of special space environmental factors, such as shock, vibration and acceleration, space food must also make appropriate adjustments to dietary nutrients according to the physiological change indicators of astronauts in weightlessness. For example, muscle atrophy requires that food must provide sufficient high-quality protein; Bone loss requires food to provide sufficient calcium, appropriate calcium-phosphorus ratio and vitamins.
How astronauts eat and drink in space flight activities is a great test for them. In weightlessness, it is the same to put a cup full of water upside down. The water in the cup will not float or overflow automatically. If you put it on the table, the cup will fly with the water. Therefore, the original eating habits of astronauts on the ground are completely inapplicable in space. Generally speaking, all kinds of food, parts and utensils are fixed. After the astronauts take out the food from the food cabinet, they should cut a small hole in the composite plastic bag containing the food, put the fork and chopsticks in their pockets and put them in their mouths. In order to prevent food residues from flying around and affecting the normal work of astronauts or equipment, this kind of food is often packaged in small packages and made into square, rectangular or small spherical "bite" foods with similar size, and it is not necessary to cut them when eating. If astronauts want to drink water, soup, soup, juice and jam, they just have to squeeze it into their mouths bit by bit from plastic bags or soft aluminum tubes like toothpaste.
With the development of rocket technology, astronauts can bring more food from the ground. Such as wet or semi-wet food, turkey with juice, beef, etc. Their water content is the same as the normal food eaten on the ground. Now, astronauts can use microwave heaters to bake food in the space capsule. This kind of microwave heater is different from the heater used on the ground. It has some special concave cells on it. In order to prevent food from floating during heating, the food to be heated must be fixed in these compartments. After being plugged in, food can be heated to a delicious level in a short time. With it, astronauts can taste hot and delicious braised beef, scrambled eggs, pork chops and other foods, and the taste is not much different from that on the ground.
Wear-a piece of clothing is worth tens of millions of dollars.
People's understanding of clothing is often limited to its characteristics of covering, keeping warm, beautiful and generous, but when people enter space, they will find that the role of space suits has already exceeded the traditional scope. Because of the pressure environment close to vacuum, extreme temperature environment, lack of oxygen needed for life, space dust, space debris and the threat of space radiation. Space suits are needed to provide a good protection and guarantee system for astronauts' life and work in space.
Space suits can be divided into in-cabin space suits and extravehicular space suits according to their functions. In-cabin spacesuit is used in the case of leakage and sudden pressure drop in spacecraft cabin. When the astronauts put it on in time and connect the oxygen and gas supply system in the cabin, the clothing will immediately pressurize and supply gas, and can provide certain temperature protection and communication functions to ensure that the astronauts can return safely when the spacecraft fails. Extravehicular spacesuit is more complicated. It is the guarantee and support system for astronauts to leave the cabin and enter the open space. It not only needs independent life support and working ability, including extreme thermal environment protection and human body balance control, oxygen supply and pressure control, indoor microenvironment ventilation and purification, measurement and control and communication system, power supply system and astronaut visual protection and support, but also needs joint system with good activity and emergency oxygen supply system in case of major system failure. The extravehicular spacesuit is structurally composed of micro-flow protective layer (outer cover), vacuum heat insulation shielding layer, airtight limiting layer, ventilation structure and liquid cooling suit, just like an independent life support system. The extravehicular spacesuit system is usually much heavier than the strong man. Its price is naturally high. At present, it costs tens of millions of dollars to develop and produce an extravehicular spacesuit.
When it comes to space suits, we can't help but talk about "space jet packs". This backpack is about 1.25m high and 830mm wide, with a total weight of 150kg. It contains 12 kg of liquid nitrogen and has 24 nozzles. It is like a chair without a seat, which is installed on the astronaut's back. Astronauts can control 24 micro nozzles to spray compressed nitrogen from the backpack through the switch on the armrest, thus forming different reverse thrust in all directions and realizing the movement in different directions. With this kind of jetpack, astronauts can freely somersault, rotate, move up and down and back and forth in the vast space.
Life-testing life skills in a closed cabin
The cosmic environment is extremely bad, and the main factors harmful to human body are high vacuum, high hypoxia, cosmic radiation, temperature difference and so on. Astronauts cannot live and work in such an environment. Therefore, scientists have developed a closed cabin isolated from the outside world to protect astronauts.
The closed cabin for astronauts to live, live and work is the main part of the spacecraft, and it is an environmental control and life support system to ensure the health of astronauts. The most important thing in life support system is water supply system. Its main task is to provide domestic water and dietary water for astronauts. The closed cabin is a narrow environment, and the pollutants that are constantly produced must be purified to keep the air in the cabin fresh and ensure the health of astronauts.
Because of weightlessness and floating, astronauts are not as free as they are on the ground. They sit unsteadily and stagger. As soon as they look up and lean back, they may make a big turn, and when they bend over, they may somersault, so all actions must be careful. In space flight, sleeping bags are usually fixed on the bulkhead of spacecraft. In weightlessness, it is the same whether you sleep standing or lying down, so an astronaut can sleep against the ceiling or upright against the wall as long as he is happy. In order to avoid accidentally touching the switch, they must put their hands on their chests when sleeping. Sleeping position in space is very special. When the body is completely relaxed in weightlessness, it will naturally form a bow posture. In the space orbit station, astronauts can already enjoy separate bedrooms and beds, but they must tie themselves to the bed when they sleep, so as not to float away due to weightlessness when they turn over.
In addition, astronauts in space flight, like people on earth, also need personal hygiene treatment, such as brushing teeth, washing face, taking a bath, urinating, etc., but these all need special facilities and skills. For example, if you brush your teeth in weightlessness, toothpaste foam will float easily, and water droplets will float in the cabin, which will affect people's health and the normal work of the instrument. In order to prevent this problem, the United States adopted a special kind of rubber candy, which allowed astronauts to chew fully instead of brushing their teeth to achieve the purpose of cleaning their teeth. Astronauts should cover their ears and wear goggles when taking a bath, just like divers. People should wear fixed slippers when entering the bathroom, so as not to float. The American space shuttle Endeavour was equipped with a space toilet, which cost as much as $23.4 million. This toilet can store and treat more feces, and has an independent urine separator, which can separate urine from feces. The airflow guide device on the toilet solves the difficulty of human excretion under weightlessness.
Line-to prevent becoming a human satellite in the vast space
1March, 965 18, Soviet astronaut leonov left the capsule of the "Ascension 2" spacecraft and walked in the vast space for the first time, which created a precedent for human spacewalking. However, spacewalking can't be compared with people walking on the ground, and its difficulty is unimaginable to ordinary people, which requires many special technical support measures.
Because space is in a vacuum, without the protection of the atmosphere, the temperature changes greatly. The temperature can be higher than 100℃ in sunshine and lower than -200℃ in no sunshine. At the same time, there are all kinds of radiation and meteors that can cause harm to human body. Therefore, when you walk in space, you must wear a special spacesuit. At the same time, because the artificial air pressure and air composition in the closed cabin of manned spacecraft such as spacecraft, space station and space shuttle are basically the same as those on the ground, the human body absorbs a certain amount of nitrogen, while the air pressure in the space suit is low, only 27.5% of the atmospheric pressure. If astronauts suddenly leave the cabin, the blood supply will be poor after encountering low pressure, and nitrogen dissolved in adipose tissue cannot be carried to the lungs through blood to form bubbles, which may cause air embolism and blockage of blood vessels. Therefore, astronauts need to suck pure oxygen to expel nitrogen from the body before leaving the cabin to avoid hidden dangers.
When spacewalking astronauts fly around the earth at high speed, there is no reference object in the vast space, so it is impossible to distinguish the distance and speed of the object. Without insurance measures, they may get lost in the vast space and become human satellites. Coupled with manned spacecraft and their own movements, astronauts sometimes get confused and may be in danger, so spacewalking needs to take insurance measures-wearing seat belts. Seat belts are like a baby's umbilical cord, connecting astronauts with spacecraft and preventing astronauts from getting lost in space. 1On February 7th, 984, during the flight of the American space shuttle Challenger 1 1, astronaut Bruce McKandri walked freely in space for the first time without wearing a seat belt for 95 minutes, and captured the satellite "The Year of the Sun Peak" that had stopped working. Bruce completed the first satellite capture mission of the space shuttle. This spacewalk has also created a new world for human space activities. But for the sake of safety, astronauts still need to wear seat belts. In case the astronaut can't walk back to the space shuttle by himself, he can be pulled back with a towing cable.
Space life seems interesting, but it is actually a big test of astronauts' survival skills. It seems that it is not easy to be an astronaut and enjoy a different life from the earth. (