The launch of Tiangong-1 marks the second step of China's "three-step" space strategy.
The so-called "three-step space flight in China":1In September 1992, the central government decided to carry out manned space flight project and determined the development strategy of "three-step space flight" in China;
The first step is to launch a manned spacecraft, build a preliminary supporting experimental manned spacecraft project and carry out space application experiments;
The second step is to break through the astronaut's extravehicular activity and spacecraft rendezvous and docking technology, launch a space laboratory, and solve the problem of manned space application with a certain scale in the short term;
The third step is to build a space station to solve the problem of large-scale long-term space application.
If the three-step plan is successfully completed, China will eventually build a basic space station. After that, China will build the fourth space launch site in Wenchang, Hainan, after Jiuquan, Taiyuan and Xichang, which will mainly undertake the launching tasks of spacecraft such as geosynchronous orbit satellites, large-mass polar orbit satellites, large-tonnage space stations and deep space exploration satellites.
Tiangong-1 docked twice: the first time:120 am on October 3/165438+docked with Shenzhou-8 spacecraft. The second time: on the afternoon of June 20 12 18 (14: 14), it successfully docked with Shenzhou 9. Third time: On June 20 13 13, 13, Shenzhou-10 and Tiangong-1 completed automatic rendezvous and docking.
Tiangong-1 target aircraft officially terminated its data service on March 16, 2065438, and fully completed its historical mission. It re-entered the atmosphere at 8: 15 on April 2, 20 18 and landed in the middle of the south Pacific. Tiangong-1 crashed into the earth under command or burned out in the atmosphere. The landing zone is located in the middle of the South Pacific, which will not become space junk and will not endanger the ground.
Tiangong-2 (official version of space laboratory)
Tiangong-2 Space Laboratory is the second space laboratory independently developed by China after Tiangong-1, which is used to further verify the space rendezvous and docking technology and carry out a series of space experiments.
If "Tiangong-1" is the experimental version of the space laboratory, then Tiangong-2 is the official version of the space laboratory.
The purpose of Tiangong-2 is mainly to carry out applications and experiments in the fields of Earth observation and space earth system science, new space application technology, space technology and space medicine. Build the first real space laboratory in China, and use it to release a small satellite when launching. The future Tianzhou-1 cargo spacecraft will dock with Tiangong-2.
Achievements of Tiangong-2 Space Laboratory:1) Launched into orbit on September 2016, and completed four rendezvous and docking with Shenzhou 11 manned spacecraft and Tianzhou 1 cargo spacecraft; 2) Tiangong-2 successfully supported two astronauts to work and live in orbit for 30 days; 3) Breakthroughly mastered a series of key technologies such as astronauts' mid-term stay and on-orbit propellant replenishment, and completed a number of expansion tests during more than 300 days of extended service;
At 2 16 on July 20 19, Tiangong-2 Space Laboratory re-entered the atmosphere, and a small amount of debris fell into the predetermined safe waters of the South Pacific.
Internal structure of Tiangong-2: First, the main part. The actual engine room has a maximum diameter of 3.35 meters, and its appearance looks very simple, and it is a cylinder. The internal device of Tiangong-2 carries the world's first dedicated high-sensitivity gamma-ray burst polarization measuring instrument, as well as related high-tech facilities such as handles, astronaut consoles and display screens that facilitate astronauts' activities in weightlessness.
Secondly, Tiangong-2 has optimized the livable environment for manned passengers, improved the dining and sleeping environment, and increased sports equipment and entertainment facilities. In fact, the space laboratory is not only a workplace, but also a warm home for rest, which can make astronauts' 30-day life in Tiangong more comfortable, convenient and colorful.
At the same time, Tiangong-2 has built a liquid loop verification system composed of mechanical, electrical and hydraulic components, as well as a manipulator operation test terminal. And the on-orbit maintenance test is carried out, which accumulates experience for the follow-up on-orbit maintenance design of the space station.
Third, Tiangong-2 is equipped with special solar panels for satellites. The wingspan width of the original solar panel is about18.4m.. It is a polymer board made of special materials, which can provide solar energy storage for Tiangong-2 and reduce the consumption of its own resources.
In addition, the Tiangong-2 Space Laboratory is also equipped with a specially customized high-performance aerospace "digital camera", which is installed on the belly of the Tiangong-2 Earth observation surface. With the change of the flight angle of Tiangong-2, imaging in multiple directions can be realized.
"Digital camera" has the characteristics of high signal-to-noise ratio, the resolution on the ground can reach 100 meters, and the details of the ground scenery are very fine. These new detection images will be widely used in many fields, such as weather forecast, atmospheric detection, climate change, agricultural production, marine disaster prevention, navigation safety and so on.
The real purpose of Tiangong-2 is to build a small space laboratory, which aims to solve the problem of space application with a certain scale and short-term care, and has the conditions to carry out all kinds of work and experiments.
Tiangong-2 Space Laboratory is loaded with 14 space application load, such as space cold atomic clock. Most of these application projects represent the international advanced level in related scientific and technological fields, and are expected to achieve a number of major application achievements, which will strongly promote the development of space science and applied technology in China, lead the scientific and technological progress in related fields, and accelerate the implementation of the innovation-driven development strategy.
What's magical about Tiangong-2?
One of the highlights: Tiangong-2 is equipped with the world's first space cold atomic clock (the cold atomic clock made of laser cooling atoms can further improve the timing accuracy), which is expected to reach the ultra-high accuracy of 10- 16 seconds, improving the timing accuracy of human beings in space by 1 to two orders of magnitude, which means that the cold atomic clock will have to run for about 30 million years before it can be produced.
Power 2: Tiangong-2 is loaded with a gamma-ray burst polarization detector. Polarization detector for gamma-ray bursts (POLAR), jointly developed by relevant scientific research institutions in China and ESA, is the world's first special equipment for measuring polarization of gamma-ray bursts with high sensitivity, which will provide an important means for studying gamma-ray bursts.
Through the highly sensitive polarization observation of gamma-ray bursts and solar flares, it is helpful to further understand the nature of gamma-ray bursts and further study the structure, origin and evolution of the universe. This load will fill the gap in the current polarization measurement method of high sensitivity gamma bursts (gamma bursts: the phenomenon that the intensity of gamma rays from a certain direction in the sky suddenly increases in a short time and then decreases rapidly, with a duration of 0. 1- 1000).
The band of mega-electron volts. Gamma-ray burst was found in 1967. )。
Qiangda III: 1) loaded with broadband imaging spectrometer; 2) loading a three-dimensional imaging microwave altimeter; 3) A new generation of earth observation remote sensing instruments and earth science research instruments such as ultraviolet edge imaging spectrometer are loaded. The application of these loads will improve China's technical level in the fields of global climate change research, air pollution and atmospheric composition monitoring.
Powerful four: equipped with an incubator. A miniature incubator with suitable temperature and controllable light was designed on Tiangong-2. The whole process from sowing to harvesting seeds can be realized. In the past, the experiment cycle of space plant culture would not exceed 20 days, and the experiment could only be carried out at seedling stage. This is the first time that China has completed the whole process of space plant culture experiment from seed to seed.
In addition, Tiangong-2 will carry out a number of new material preparation experiments and space experiments in basic scientific fields such as fluid physics, and will also release an accompanying satellite to carry out joint experiments with Tiangong-2.
Achievements and significance of Tiangong-2
1. Docking of Tiangong-2 and Shenzhou-11 spacecraft: The rendezvous and docking technology of China spacecraft has been comprehensively tested and proved, which is an important symbol that China people have thoroughly cracked and mastered the most advanced technology monopolized by the Soviet Union and the United States for 50 years. China is even the second country in the world that can realize space teaching. This technology requires antenna communication, which only the United States and China can do at present.
Second, the space station can accommodate many people for a long time: Jing Haipeng and Chen Dong lived in the space station for 33 days, setting a record for the longest manned space flight in China, which indicates that China has the ability to build a space station where astronauts can stay for a long time.
Third, the docking of the space station and Tianzhou-1: Tianzhou-1 is China's first cargo spacecraft, and the docking with Tianzhou-1 is a very important ending battle for the mission of China's space laboratory. The successful docking of China's first cargo spacecraft means that China people have mastered the long-term stable cargo technology of the future space station.
Fourth, on-orbit refueling: the so-called space refueling. This technology was completed by Tianzhou-1, which means that the fuel supply technology for China's long-term in-orbit flight in the future Tiangong Space Station is mature.
5. Complete 14 high-level space experiment: The most interesting space cold atomic clock experiment is the first time in the world, especially the quantum communication experiment, which is a major technological breakthrough completed in China in recent years. In addition, there are biological experiments.
Sixth, the space station completed the manipulator experiment: Tiangong-2 conducted the first experiment in China.
The mechanical arm is an essential artifact for China to build a space station, maintain and transport extravehicular activities and rendezvous and docking spacecraft in the future. The mechanical arm in the experiment requires a series of harsh requirements, such as light weight, high strength, high degree of freedom and complex functions.
7. Adopt advanced modular system design. If the space station has technical problems, it can be quickly replaced and maintained in orbit, which is also an important breakthrough in China's space technology.
8. The satellite and skylink technology of the space station have matured. China designed Tianlian Communication covering the whole world to realize barrier-free communication between heaven and earth at any time. At present, only China and the United States have this cutting-edge technology. Therefore, Chinese astronauts can watch the news broadcast on the space station.
9. Complete international cooperation: China's space station carries the world's first dedicated high-sensitivity gamma-ray burst polarization measuring instrument. The cooperation project between China and Switzerland shows that China has opened the door to international cooperation in the space field.
10. Accelerate the construction of China's space station: For example, Tiangong-1 and Tiangong-2, which have been out of service, helped China master the relevant technologies for manufacturing and building the future Tiangong space station in advance, and the planned Tiangong-3 was cancelled.
Tiangong-2 has been in orbit for more than two years, and its earth observation has achieved fruitful results. Up to now, the space application system of China's manned spaceflight project has distributed 37TB of data products such as earth observation load and supported more than 70 related projects. Breakthroughs and verifications of a number of new technical systems and key technologies have been achieved on Gong-2, and relevant technical achievements have been transformed and transferred to operational applications such as ocean color satellite, ocean power satellite, Fengyun precipitation measurement satellite and Fengyun meteorological satellite. With the adoption of these new technical systems and the great improvement of equipment functions and performance, the application breadth and depth of Earth observation are constantly expanding.
At 2 16 on July 20 19 of Tiangong-2 Space Laboratory, under the command of the ground commander, the main body burned in the atmosphere and a small amount of debris fell into the scheduled waters of the South Pacific.
Compared with Tiangong-1 target aircraft, it belongs to uncontrolled reentry. Tiangong-2 achieved controlled deorbiting, which is the second time that China has implemented spacecraft controlled deorbiting after Tianzhou-1 cargo spacecraft. The purpose of controlled deorbiting: to eliminate the threat that Tiangong-2 may pose to the space and ground environment in the future.
Why should we take a controlled derailment?
With the increasing service time of Tiangong-2, the on-orbit reliability will decline. Once there is an in-orbit anomaly, Tiangong-2, which is out of control in near-earth orbit, will gradually fall. After falling into the atmosphere, some high melting point substances may not be completely burned, and a small amount of debris will fall to the ground, endangering the safety of people on the ground.
At present, there are more than 20,000 space debris with a diameter exceeding 10cm around the earth, and the impact of space debris with a diameter exceeding 10cm on spacecraft will be a disaster. Therefore, there is a lot of space junk in space, which often makes the spacecraft have to change its route and avoid obstacles. Therefore, actively destroying spacecraft has become international common sense.
What do you think of the destination of the spaceship?
Spacecraft debris must fall into the designated place, the so-called "spaceship cemetery". For example, the wreckage of Tiangong-2, like Tiangong-1 and Tianzhou-1, fell into the South Pacific.
According to the China Manned Space Engineering Office, a small amount of the remaining wreckage of Tiangong-2 will fall into the predetermined safe sea area within the range of west longitude 160 ~ 90 degrees and south latitude 30 ~ 45 degrees in the South Pacific.
It is an international practice to belong to this aspect. After the large spacecraft, which usually runs in near-earth orbit, is retired, the common plan in all countries is to let the spacecraft fall into the deep sea area of the South Pacific under control. This area is more than 2000 kilometers away from the land in all directions. It is important that there is almost no human activity in this area. Due to the influence of ocean currents, there are few marine life, so it will not cause too much damage to the ecology, so it is called "spacecraft cemetery".
According to statistics, in the past 50 years, about 15000 tons of spacecraft debris have fallen back to the earth, and there has never been an incident that harmed residents in densely populated areas. According to the statistics of NASA, in 20 14 years alone, more than 600 failed satellites, abandoned rocket stages and other debris entered the earth's atmosphere, with a total mass exceeding 100 tons, but no reports of personal injuries or property losses were received.
In history, there were 1979 spacecraft wrecks that fell to the earth, and the American "Skylab 1" fell to the earth, but the designated location of the final fall was far from the forecast. NASA originally planned to land in the ocean 1300 km south of Cape Town, South Africa, but the debris eventually landed in the desert areas of the South Indian Ocean and Western Australia. However, "Skylab 1" fell in a partially controllable way, so the spacecraft with completely controlled entry can fall to a safe area more accurately.
According to statistics, since 2000, the success rate of 1200 space launches in the world is about 94.3%. After all, space launch is a high-risk activity. China undertook the launch mission of Tiangong-2 Space Laboratory-Long March II F.
The quality of T2 rocket is very reliable, and it has successfully carried out 1 1 launch mission, and achieved continuous success. With such income, China has been strengthening the whole process quality control in strict accordance with procedures and norms with the attitude of "starting from scratch" to ensure the development quality of flight products.
Manned space flight is the top technology with the most complex system, the most intensive technology and the most active innovation in the global science and technology field. It covers many scientific fields, such as mechanics, astronomy, earth science, space medicine, space science and so on, involving systems engineering, automatic control, computer, space power, communication, remote sensing, new energy, new materials, microelectronics, optoelectronics and other engineering technologies.
Since the implementation of 1992, China's manned spaceflight project has broken through and mastered a series of core key technologies in the process of organizing the implementation of 12 space mission, obtained nearly 1,000 national invention patents, promoted the construction of China's space infrastructure, and made China's space science and technology cause achieve leap-forward development.
Over the past 20 years, more than 2,000 technological achievements in China's manned spaceflight have been widely used in various industries of the national economy. According to the calculation of relevant research institutions, the input-output ratio is between1:/kloc-0 ~1:12. Manned space flight has also promoted technological innovation, technological innovation and industrial upgrading in the fields of raw materials, microelectronics, machinery manufacturing, chemical industry, metallurgy, textiles, communications, etc., expanded the channels for transforming scientific and technological achievements into real productive forces, and injected impetus and vitality into the development of high-tech industries.
Honors won by Tiangong-2
Time magazine of the United States selected 25 best inventions in the world in 20 16, and Tiangong-2 Space Laboratory was among them. This is the first time that spacecraft products from China have appeared on this list.
The honor ceremony of "Influence China" 20 16 selected by China Newsweek was held in Beijing. China Aerospace Science and Technology Group Tiangong-2 and Shenzhou-11 manned space mission development teams won the annual scientific and technological figures.
Global Scientific American magazine selected the top ten global science news in 20 16. Tiangong-2 and Shenzhou-11 manned missions were successfully selected.