Shenzhou spaceship is a satellite spacecraft developed by China. The spacecraft consists of propulsion module, return module, orbital module and additional parts, with a total length of 8.86 meters and a total weight of 7790 kilograms. Shenzhou rocket was sent into low orbit by Long March 2F rocket.
structure
Propulsion module
The propulsion cabin of the spacecraft is located at the tail of the spacecraft, and its shape is cylindrical. It is equipped with four main engines and translation engines, and more than 20 square meters of main solar arrays are installed on both sides. The propulsion module is mainly used for attitude control, orbit change and braking of spacecraft.
re-entry module
The spacecraft's return capsule is located in the middle of the spacecraft, with a large blunt inverted cone, a diameter of 2.5 meters and a space of about 6 cubic meters, which can accommodate three astronauts. It is the spacecraft with the largest available space in the world at present. The shape of the spacecraft's return capsule is designed according to some lifting body, and the spacecraft adopts lift reentry mode. The spacecraft adopts the dome parachute recovery scheme, and the parachute area is1200m2, making it the largest parachute in the world.
Orbital module
The orbital module of the spacecraft is located at the front end of the spacecraft, which is cylindrical, with cone angles at both ends, and [solar cell] array, solar sensor, antenna and docking mechanism are installed at both sides. Orbital module is the living module, test module and cargo module of astronauts during their in-orbit flight. The orbital module has the ability to keep the orbit and can work continuously in orbit for more than half a year. The orbital module launched last time can rendezvous and dock with the next spacecraft, which saves the number of rendezvous and docking launches and reduces the overall cost of manned space program. The additional segment of the spacecraft is mainly used for the rendezvous and docking of the spacecraft, and it is generally decided whether the additional segment is needed according to the mission content.
Tasks performed
So far, China has launched six series of spacecraft from Shenzhou I to Shenzhou VI, of which Shenzhou 5 and Shenzhou VI are actually manned.
-[[Shenzhou-1 (1999165438+1October 20th)-The first test flight successfully realized the round trip between heaven and earth.
-Shenzhou II (200 1 year 65438+1October 9)-the first unmanned spacecraft prototype. The main purpose of flight test is to check the whole process of the whole project and each system from launch to operation, return and orbit maintenance, to check the correctness and matching of the overall technical scheme and the technical scheme of each system, and to obtain data related to manned flight and scientific experimental data.
-Shenzhou III (March 25th, 2002)-The main purpose of flight test is to check the functions of rocket escape, redundancy of control system, spacecraft emergency rescue, autonomous emergency return and manual control. This task includes simulating astronauts.
-Shenzhou IV (June 5, 2002 to June 38, 2002+February 29, 2002)-Integrated flight test in unmanned state. The main purpose of flight test is to further improve and assess the reliability of rockets, spacecraft and measurement and control systems to ensure the absolute safety of astronauts.
-Shenzhou 5 (June 65438 +654381October+May 2003)-First successful manned flight. Carrying astronaut Yang Liwei around the earth fourteen times.
-Shenzhou VI (10, 2005, 12)- with astronaut fees and Nie Haisheng's first multi-person multi-day space flight.
plan target
The difference between manned spacecraft and rockets is that rockets are just tools to transport spacecraft into space. After entering space, the rocket's mission is completed, and it gradually falls off and enters the atmosphere.
What's the difference between a manned spaceship and a cargo spaceship? 1, life support system
2. Return technology
These two points are the technical difficulties of manned spacecraft and the biggest difference from cargo spacecraft. The cargo ship has nothing to do with life, and returns to burn directly in the atmosphere.
What's the difference between a spaceship and a rocket? A rocket is just a means of transportation. It puts a satellite or spacecraft into orbit to complete the task.
China has launched many artificial earth satellites,
These are unmanned spacecraft. The main difference between Shenzhou manned spacecraft and them is that special systems such as environmental control and life support system, astronaut telegraph system, instrument and lighting system, space suit and emergency escape device are added to provide services for astronauts. In addition, the manned spacecraft has a large space for activities; Structural sealing performance must be good; There is also the equipment needed to return to earth, that is, the return landing system. Therefore, the Shenzhou manned spacecraft is bigger and more complicated than the satellite.
Satellites do not have these design requirements. For example, its cabin does not need to be sealed and does not need a lot of free space, so it has a simple structure and a single task. Unless it needs to be returned to Earth for special purposes, it will generally not be recycled.
Compared with satellites, spaceships have the following characteristics:
First of all, the return module and orbital module of astronauts' life must be reliably sealed to keep the cabin within the specified atmospheric pressure range. Of course, absolute sealing is impossible, and it is necessary to constantly replenish the gas source. But we must put an end to accidental leakage to avoid catastrophic accidents. 197 1 On June 30th, 2008, all three Soviet astronauts died in Soyuz spacecraft before returning to their places. The reason is that the cabin leaked air, and they didn't put on their spacesuits in time, which led to the death of astronauts due to acute hypoxia and boiling body fluids.
Second, manned spacecraft must have environmental control and life support systems. It is a complex system integrating mechanics, electricity, thermal technology, medicine and environmental engineering. It is not only used to maintain the specified atmospheric pressure in the cabin, but also to adjust the proportion of oxygen and nitrogen in the atmosphere. Eliminate harmful gases such as carbon dioxide exhaled by the human body; The most suitable temperature and humidity in the cabin are generally within the range of 18℃ ~ 25℃. In weightlessness, the air in the spacecraft cabin will not naturally convection, so the temperature and humidity inside are very uneven, and it is difficult to eliminate the heat in the cabin. Therefore, ventilation equipment must be configured for forced convection ventilation. It will also provide astronauts with basic living conditions such as drinking water, washing water, food, sleeping bags and urine collectors. Due to the small space in the spacecraft, luxury facilities such as bedroom, kitchen, dining table, bathroom, shower and sports equipment can only be abandoned.
The third is high reliability. This is the most important point of manned space flight. In order to ensure foolproof, some key components of manned spacecraft use double backup or even three backup, and a large number of ground tests and simulated flight tests are needed before going into space to eliminate hidden dangers.
Fourth, there must be an emergency escape device. Life is a matter of life. Therefore, the emergency rescue devices on spacecraft include ejection seats, rescue towers and manned mobile devices, which have their own uses in different stages of flight.
From the moment the astronauts enter the spacecraft, after getting ready on the launch pad, the launch vehicle ignites, takes off, ascends, the spacecraft enters the orbit, runs in orbit, leaves the orbit after the mission, re-enters the atmosphere, opens the parachute and makes a soft landing until the astronauts are found and picked up by the ground personnel. The whole process must be equipped with an emergency rescue system and a preset emergency rescue plan to ensure the safety of the astronauts.
In space flight, the most dangerous stage is the ignition, take-off and ascent of the launch vehicle. When the spacecraft is docked with the launch vehicle on the launch pad, an escape tower consisting of several small rockets must be installed at the top of the spacecraft. From then on, until the launch vehicle carries the spacecraft to a height of 1 100 km above the ground, during this period, once the rocket is in serious danger, which may endanger the safety of the spacecraft and astronauts, the rocket escaping from the lifesaving tower will be ignited immediately, and the orbital module and the return module will be pulled away from the rocket and flown to a safe area, and then the escape tower and the orbital module will be thrown away, and the return module will return and land safely.
If the spacecraft is unable to continue its operation due to a major failure during the on-orbit operation, it is necessary to perform the return procedure in advance. According to the position of the track relative to the ground at that time, choose to land at the main landing site or emergency landing site; If the situation is critical and it is urgent to return immediately, the astronauts will immediately enter the return capsule, leave the orbit and return to the ground. In this case, most of the crash landing in the return capsule will land on the high seas or overseas. There are emergency daily necessities (such as food, drinking water, GPS receiver and communication machine, etc.). ) in the return capsule, and the astronauts will play their own self-help survival ability in the desperate situation of loneliness and helplessness in order to wait for the arrival of rescuers.
Safe return is the last link of manned space flight, which is not easy. In 2003, the space shuttle Columbia crashed on its way back. For the spacecraft, there are four "gates of hell" when returning:
The first is attitude adjustment, which makes the spacecraft adjust from running attitude to returning attitude, including the separation of orbital module and return module-propulsion module.
The second is braking. When a spacecraft enters the atmosphere at high speed, it will have a huge impact overload, just like an airplane hitting a mountain, so the overload must be limited to the human tolerance. The method is to reduce the speed of the spacecraft by starting the rocket engine in the propulsion module to produce braking.
Third, when the spacecraft returns, the intense friction with the atmosphere will produce thousands of degrees of high temperature, so advanced heat protection measures must be taken, otherwise the steel bars and iron bones will be reduced to ashes. When re-entering the atmosphere, the cabin bottom made of special heat-proof materials should be kept forward to ensure the normal temperature in the cabin under the high temperature and high pressure caused by severe friction with air.
The fourth is the landing gap. After the return capsule descends into the dense atmosphere, the recovery control system starts to work, and the parachute is opened to further slow down. Before landing, the landing buffer device began to work, which made the return capsule achieve a soft landing at a very low speed (below 2 ~ 3m/s) and ensured the safety of astronauts. This last level is extremely important, otherwise all previous efforts will be in vain. The Soviet Union 1 Soyuz spacecraft was killed when the parachute rope was entangled and the parachute could not be opened, and the return capsule rushed to the ground at a very high speed. In addition, it is necessary to ensure the accuracy of its landing point in order to find rescue in time. A Soviet spaceship could not be found by rescuers because of its poor landing accuracy, and the astronauts trapped in the frozen forest almost froze to death.
China is the third country in the world with recoverable satellites. Successfully launched 17 satellites and returned 16 satellites. China has mastered the satellite return technology and rich experience in developing high-reliability recovery system, which has laid a solid foundation for the safe return and landing of Shenzhou manned spacecraft.
To sum up, manned spacecraft is much more complicated than satellites, with extremely high cost and great risk. However, it is precisely because the manned spacecraft can be directly operated by astronauts, which greatly expands the functions and uses of the spacecraft and has an immeasurable and great impetus to human civilization and progress.
The most important thing is that they have different uses:
Spaceships are used to fly between outer space, for example, from the Earth to proxima centauri ... Their structures, working methods and shapes are also quite different for different purposes. What the space shuttle needs most is to get rid of the gravity of the earth, so it has its own power system and huge external fuel tank (the thickest yellow one under the common American space shuttle). In order to reduce the air resistance and make full use of the aerodynamic force when landing, the space shuttle has a very beautiful aerodynamic shape and the spacecraft also has a power system. But at present, the power supply is mainly solar cells, and no external power supply is needed. In addition, although the spacecraft is flying in outer space, it has no special requirements for appearance, so it looks ugly. In addition, the space shuttle was originally an alternative to the launch vehicle proposed by the US military. The design requirements are not only manned and transport satellites. Being able to go back and forth and be reused is also the most important performance indicator. Spaceships are usually designed for a specific purpose. For example, Shenzhou VI, in addition to its internal structure, is largely designed for the safe return of astronauts. The spaceship you see in science fiction, especially in comics, has not yet appeared and will not be made in the short term.
What's the difference between manned spacecraft and manned spacecraft? Manned spaceship is a spaceship carrying astronauts.
Spacecraft refers to man-made spacecraft. (It may be manned or unmanned)
Manned spacecraft refers to all spacecraft carrying astronauts, such as spacecraft, space shuttle, space shuttle and so on.
What's the difference between a manned spaceship and a space shuttle? The manned spacecraft is disposable, and the space shuttle is reused many times. Manned spacecraft can carry out space activities independently, can also be used as a "ferryman" between the ground and the space station, and can also dock with the space station or other spacecraft for joint flight. The manned spacecraft is small in size and limited by the amount of consumable materials it carries, so it cannot be replenished and reused.
What's the difference between a spaceship and a rocket? Manned spacecraft, also known as spacecraft, is a one-time spacecraft that transports astronauts into space and returns safely. Basically, astronauts can live in space for a short time and do some work. Its running time is usually a few days to half a month, and it usually needs two or three astronauts.
The first manned spacecraft in the world was the "Oriental" spacecraft 1. It consists of two cabins, the top of which is a sealed manned cabin, also known as the astronaut cockpit. This is a sphere with a diameter of 2.3 meters. The cabin is equipped with a life support system that can guarantee the life of astronauts, as well as an attitude control system to control the attitude of the spacecraft, a beacon system to measure the flight orbit of the spacecraft, a parachute recovery system for landing and an ejection seat system for emergency rescue. The other cabin is the equipment cabin, which is 3. 1 m long and 2.58 m in diameter. There are braking rocket systems, batteries for supplying electric energy, gas cylinders, nozzles and other systems in the equipment cabin, so that the manned cabin can leave the flight track and return to the ground. The "Oriental" spacecraft 1 has a total mass of about 4700 kg. Both it and the launch vehicle are disposable and can only perform one mission.
Rocket: A rocket is just a means of transportation. It puts a satellite or spacecraft into orbit to complete the task. A space vehicle consisting of multi-stage rockets. The purpose is to send payloads such as artificial earth satellites, manned spacecraft, space stations and space probes into predetermined orbits. It is developed on the basis of missiles and generally consists of 2~4 stages. Each stage includes the rocket structure, propulsion system and flight control system. There is an instrument cabin in the last stage, which contains guidance and control system, telemetry system and launch site safety system. These stages are connected by interstage parts. The payload is installed on the instrument cabin, and the fairing is sleeved outside.
Many launch vehicles are bundled with booster rockets around the first stage, also known as zero-stage rockets. The booster rockets can be solid or liquid rockets, and their number is selected according to the need of carrying capacity. Most propellants are liquid two-component propellants. The first and second stages use liquid oxygen and kerosene or nitrogen tetroxide and mixed hydrazine as propellants, and the last stage rocket uses high-energy liquid oxygen and liquid hydrogen propellants. Most guidance systems use autonomous full inertial guidance systems. Launch in a special launch center (see spacecraft launch site). Technical indicators include carrying capacity, orbit accuracy, adaptability and reliability of rockets to payloads with different weights.
At present, the commonly used launch vehicles can be divided into three types according to the propellants used: solid rockets, liquid rockets and solid-liquid hybrid rockets. For example, cz-3 in China is a three-stage liquid rocket; The Long March 1 carrier rocket is a solid-liquid mixed three-stage rocket. Its first and second stages are liquid rockets, and the third stage is solid rockets. The American Pegasus carrier rocket is a three-stage solid rocket.
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