Everything grows by the sun, and human spaceflight depends on rockets.

In the last month of 2020, 65438+February, the aerospace field was very lively. China's Chang 'e V successfully sampled and returned to the moon, successfully completing the first phase of the lunar exploration project. The starship prototype SN8 of American Space Exploration Technology Company is no longer a stainless steel jar that jumps 100 meters like previous times, but it has reached the height of 12.5 kilometers. Although it finally landed and exploded, it was also a successful failure. Two days ago, China's new carrier rocket Long March 8 also made its first successful flight. It is said that a reusable version will be developed in the future, and the China Falcon 9 is just around the corner.

Just when these space hotspots haven't subsided, news broke out recently that China's manned space project will complete the last step of the three-step process at this stage, "China's manned space station construction" next year.

According to the plan, the Tianhe core module and the experimental module of Tiangong Space Station will be launched next year, followed by manned spacecraft Shenzhou 12 and Shenzhou 13 and cargo spacecraft Tianzhou-2 and Tianzhou-3.

In 2022, the Meng Tian Experimental Module will be launched, and two manned spacecraft and two cargo spacecraft will also be launched. From 202/KLOC-0 to 2022, a total of *** 1 1 space launches were carried out, and the construction of a manned space station was finally completed. China Space Station will be transferred to the on-orbit operation stage, and launching manned spacecraft after 2022 will become the norm.

China's manned spaceflight project began on September 2, 1992 1,1,with the code "92 1". From Shenzhou I in 1999 to Shenzhou XI in 20 16, China * * launched1shenzhou spaceship, sent Yang Liwei and others 1 1 astronauts into space and successfully returned to Earth, with a success rate of/kloc. In addition, the Tianzhou-1 cargo spacecraft, Tiangong-1 target aircraft and Tiangong-2 space laboratory were launched for preliminary technical verification and testing of space station construction. Through this series of space missions, China has mastered a large number of key technologies, such as manned space flight, astronaut extravehicular activities and spacecraft rendezvous and docking. A special way for China's manned spaceflight project.

To build a space station, we have to say that our Hercules Long March 5 carrier rocket, which has the largest carrying capacity in China, has a core diameter of 5 meters and is affectionately called "Fat Five". Only it can send a space station weighing dozens of tons into space.

Long March 5 can be said to be the epitome of China's current launch vehicle technology. We can launch deep space probes, such as Tian Wen-1 Mars probe, Chang 'e-5 lunar probe, and Tianhe-1 core module and questionnaire experimental module to be launched next year. At present, the Long March 5 has two main configurations. One is the basic type, and the other is the Long March 5 B.

The basic Pangwu is a two-stage four-booster type, with a total length of 56.97 meters and a first-stage rocket diameter of 5 meters. It is equipped with two YF77 liquid oxygen liquid hydrogen engines with a thrust of 50 tons, and each of the four boosters is equipped with two YF100t liquid oxygen kerosene engines. The second stage rocket is also 5 meters in diameter, and two YF75D liquid oxygen liquid hydrogen engines with 9 tons of thrust are installed. The basic model is equipped with 12 engines. It was used to launch Chang 'e V this year.

Pangwu in the B configuration of Long March 5 is a one-stage four-boost configuration with a total length of 53.66 meters. Cancel the second level, and the other basics are the same as the fat five basic type. It is used to launch various parts of the space station.

After talking about the fat five who launched the space station, I have to talk about the arrow used to launch the manned spacecraft.

Manned space flight, manned space flight begins with the word "manned". Since it is manned, the most important thing is to ensure the safety of people, which means that we have to talk about the Long March 2F launch vehicle, which is also commonly known as the "God Arrow".

Shen Jian's research and development began in 1992 and 92 1 projects. Sun Tzu's art of war goes: "The military and horses have not moved food and grass first." If we regard our manned spaceflight project as a battle, then our magic arrow is "grain and grass". If we want to send people into space, we must first build a very, very safe and reliable rocket. This is a big rocket, with a total length of 58.34 meters and a diameter of 3.35 meters. It has four boosters and an escape tower at the top. It is also the longest rocket in China at present. As a rocket specially designed for manned spaceflight, its reliability reaches 0.97 and the safety of astronauts reaches 0.997. So far, the success rate of 14 is 100%. From Shenzhou 1 to Shenzhou 1 1 spacecraft, together with the experimental space laboratories of Tiangong-1 and Tiangong-2 and a mysterious reusable experimental spacecraft, they were all launched with it, which can be described as real arrows.

The Shenzhou 12 and Shenzhou 13 manned spacecraft launched next year will still use the Shen Jian Long March 2F if there are no accidents. In fact, this magic arrow Long March 2F has been in service for more than 20 years. Although many improvements have been made in the middle, it still belongs to the product of the last century. Many technologies are out of date, such as nitrogen tetroxide, unsymmetrical dimethylhydrazine and other toxic, environmentally friendly and expensive substances are still used in its propellant.

Of course, our astronauts have started to upgrade their rockets, and the main model of China's new generation of launch vehicles, Long March 7, will soon replace Long March 2F. Speaking of Long March 7, some friends may think that there is still Long March 7. I knew it. Long March 5. It is true that Fat Five is so famous that other new rockets, such as Long March 6 and Long March 7, are not impressed.

In fact, the Long March 7 should be the absolute main force of a new generation of launch vehicles. 20 16 On June 25th, Long March 7 made its first flight at Wenchang Space Launch Site in Hainan. This is the first launch mission of Hainan Wenchang Space Launch Site, the fourth space launch center in China, and the first launch of Long March 7, the first medium-sized rocket in a new generation of launch vehicles I have ever seen. You said that the Long March 7 was awesome.

Long March 7 is a medium-sized launch vehicle with two stages and four boosters. Its reliability design index is 0.98, which is higher than that of Shen Jian Long March 2F. It has two versions, one is the freight version and the other is the manned version.

The cargo version of the rocket has a total length of 53.2 meters, a takeoff mass of 593 tons, a takeoff thrust of 735 tons, and a target orbital carrying capacity of not less than 13.5 tons. It can also launch satellites, with a carrying capacity of 5.5 tons in 700 km SSO (Sun Synchronous Orbit).

The manned version of the rocket has a total length of 59.4 meters (currently the longest rocket in China, with a new length). The takeoff mass is 597 tons, the takeoff thrust is 735 tons, and the target orbital carrying capacity is not less than 1 1.5 tons.

The first stage and four main propellers of these two versions all adopt 120 ton high thrust YF 100 liquid oxygen kerosene engine. The second stage adopts 4 18 ton YF 1 15 liquid oxygen kerosene engines, which are small thrust engines and can be used flexibly.

In order to cope with the rainy and windy weather conditions at Wenchang launch site in Hainan, the Long March 7 has certain waterproof ability and launch ability in rainy weather. The newly developed windproof device is not only waterproof, but also wind-resistant, and has the ability to carry out rocket transition in gale weather of level 8.

Long March 7 is an all-around player who can transport goods, carry people and launch satellites. According to the plan, it will gradually replace the Long March 2, 3 and 4 rockets in the future and undertake 80% of China's space launch mission.

Then some friends may ask: Since Long March 7 is so awesome, will Shenzhou 12 and Shenzhou 13 manned spacecraft, Tianzhou-2 and Tianzhou-3 cargo spacecraft be launched with it next year?

Because manned space launch requires high reliability and safety of rockets. After all, Long March 7 is a new rocket, and as the absolute main rocket in the future, it must be tested and launched many times before it can be put into mass production and use until all technologies are mature and stable. Although Long March 7 has been successfully launched twice, the improved Long March 7 A rocket based on Long March 7 failed in the first round, so its reliability and safety performance may be almost meaningless compared with Shen Jian's old Long March 2F. Therefore, next year's Shenzhou 1 1 and Shenzhou 12 manned spacecraft should continue to use our old Long March 2F rocket. Tianzhou-2 and Tianzhou-3 cargo spacecraft will be launched by Long March 7.

Finally, let's talk about the basic situation of our new generation Long March launch vehicle series, so that everyone can have a general understanding of our new rocket.

Long March II, III and IV have been in service for decades and made outstanding contributions to China's space industry. China's major space achievements, such as shenzhou spaceship, Chang 'e probe, Beidou satellite global navigation system and other satellites of various models and uses, were all accomplished by them. However, the old Long March rocket was the product of the last century, and many technologies and functions can no longer meet the requirements of space missions in the new era, so a new generation of launch vehicles in China, the New Long March Series, was born.

The new Long March series rockets have completely solved various functional defects of the older generation rockets, and the design goals are non-toxic, environmentally friendly, modular and standardized, high reliability, easy maintenance, low cost, high adaptability and short development and production cycle. To sum up briefly, the new generation of launch vehicles is "one series, two engines, three modules"

One series means that the new rocket belongs to the Long March series, and the two engines refer to the liquid oxygen kerosene engine and the hydrogen-oxygen engine, and also refer to the small thrust engine and the large thrust engine. The three modules refer to cores with a diameter of 2.25m, cores with a diameter of 3.35m and cores with a diameter of 5m. By matching different levels, different types of engines and different sizes of module cores, they can be combined to meet the launch requirements of various space missions. So far, several models of the new generation Long March rocket series have successfully made their first flight. It mainly includes Long March 6 (small 2.25m core class), Long March 5 (large 5m core class), Long March 7 (medium 3.35m core class) and Long March 8 (medium 3.35m core class). The next step is to solve all kinds of problems exposed during the launch of these rockets, improve their reliability and maturity, and then gradually replace the old Long March series.

Here we should focus on the heart of a new generation of rockets: two main engine models, YF 100 and YF77, both of which use environmentally friendly propellants, with lower cost and greater thrust.

Let's talk about the handle of China rocket engine, the first generation 120-ton afterburning liquid oxygen kerosene rocket engine in China. This engine is based on the RD- 120 engine obtained by China from the former Soviet Union (Vienna's liquid oxygen kerosene engine is the only one in the world). It will be the standard of the new generation of Long March rockets in China in the future, and can be seen on the Long March 5, 6, 7 and 8. Really.

Besides YF 100, a fist engine with large thrust of liquid oxygen and kerosene, YF77 engine is a 50-ton hydrogen-oxygen engine, which is the engine that China astronauts love and hate. Because this engine has been dragging, many planned space missions have been pushed back and forth. Both Chang 'e V and the space station have been delayed for several years because of this cargo, otherwise the astronauts of the space station will have to change several waves now, and the lunar exploration may be Chang 'e VIII.

Hydrogen-oxygen rocket engine has the excellent advantage of high specific impulse and the highest thrust efficiency among rocket engines. However, because liquid oxygen and liquid hydrogen need extremely low temperature to ensure liquid storage, and engine combustion will produce thousands of degrees of high temperature, so the extremely cold and hot working conditions are like two worlds of ice and fire, which requires very high engine materials and processing technology. Therefore, the development of hydrogen-oxygen engine is relatively difficult and complicated. YF77 has been developed in China for more than ten years, and its thrust is only about 50 tons, which is still far from the mainstream hydrogen-oxygen engine in the world. And as far as the current situation is concerned, YF77 can only be said to be useful and usable, but it is not reliable. After all, I only flew a few times and failed once. It can be seen that this thing is really too difficult.

Through the development of a new generation of Long March rockets, it has basically caught up with the technical level of mainstream rockets in the world. Although there are still many technical indicators far from the international advanced level. But the current rocket technology can basically meet the needs of our new era space engineering. Our country has always had its own rhythm and pace for the development of the space industry, and has always been doing more with less money. Now, with the continuous rise of the country's comprehensive strength, the country has also increased its investment in the space industry, so our catch-up speed is also accelerating. Our country has started to upgrade new Long March rockets, such as smart rockets and reusable technologies. According to the plan, by 2035, basically all the main Long March rockets will be smart reusable rockets.

In addition, we have begun to develop the Long March 9 with greater thrust, and some key technologies have made breakthroughs. This is a heavy rocket developed for manned landing on the moon and Mars. According to the plan, Long March 9 will make its first flight before 2030. If all goes well, our rocket technology level will enter the first echelon in the world by then.