Let's first understand that the Long March 6 was changed into a launch vehicle.
The launch vehicle is a new generation of non-toxic and pollution-free launch vehicle in China, and it is also the first solid-bound launch vehicle in China, which is used to launch sun-synchronous orbit. Pujiang-2 satellite is mainly used for scientific experimental research, land and resources investigation and other tasks, while Tiankun-2 satellite is mainly used for experimental verification of space environmental monitoring technology. The Long March 6 carrier rocket is an improved version of the Long March 6 rocket and the first solid-liquid bound rocket in China. The main arrow uses non-toxic and pollution-free liquid oxygen and kerosene propellants, and the four boosters use solid boosters. This type of rocket not only fills the gap of heavy load in China's 700-kilometer sun-synchronous orbit, but also breaks through many key technologies, such as segmented high-thrust solid booster, bundling and separation of solid booster, high-power electromechanical servo mechanism, etc., and injects new impetus into the improvement of China's core space launch capability.
Then, the carrier rocket Long March 6 successfully made its first flight. What are the key messages that deserve our attention? Let me summarize it for you.
Cross-border combination of solid-liquid engine
The rocket has a two-and-a-half stage configuration, a total length of about 50 meters, a take-off weight of about 530 tons, and a carrying capacity of not less than 4 tons in a 700-kilometer sun-synchronous orbit. The first and second stages of the rocket core are 3.35 meters in diameter. The first stage adopts two liquid oxygen kerosene engines with thrust 120 tons, and the second stage adopts liquid oxygen kerosene engines with thrust 18 tons. The core stage is bundled with four 2-meter-diameter boosters, each of which is equipped with a solid motor with a thrust of 120 tons.
Compared with other rockets in China, the biggest difference of Long March 6 is that its main rocket part adopts liquid engine, while the booster tied around it adopts solid engine. Liquid engine has high performance, long working time, large thrust of solid engine and simple use and maintenance. The combination of the advantages of the two makes the rocket more reliable and cost-effective.
The first intelligent launch site was put into use.
The 9A station of Taiyuan Satellite Launch Center used in this mission is the first intelligent launch site in China. The launch site uses the Internet of Things technology to collect and integrate the data of all facilities and equipment on the ground, and integrates them through big data technology, thus realizing the whole system situation awareness, intelligent control and driving support in the whole process, greatly improving the space launch efficiency and the stability and safety of the launch command system. It is reported that the operation of the 9A station has started the journey of building a new generation of intelligent launch site in China, which is of great significance for simplifying the launch process, improving the launch efficiency and enhancing the launch stability and safety.
"Tie it tight and separate it."
The solid-liquid combination of booster and core stage requires "firm combination and separation". Changliu Reform connects the unlocking device through the binding of "front-end auxiliary force transmission+rear-end main force transmission", which is equivalent to connecting the booster with the core stage by "shoulder+lift". In order to further optimize the structural weight, Liu Chang changed the launch vehicle into a lightweight binding connection unlocking device, which can bear and effectively transmit the axial and radial loads of the launch vehicle during parking and flight.
A clever brain is the icing on the cake.
Liu Chang Rocket is also equipped with a "healthy housekeeper" to make the rocket more intelligent. Different from the ignition process of conventional launch vehicles, when the rocket is launched, the first-stage engine with long six rocket cores is ignited first, and then four solid motor boosters are ignited.
After the core engine is ignited, the engine health diagnosis system starts to work. At this time, the solid booster has not been ignited to generate strong takeoff thrust, and the weight of the four boosters can firmly fix the whole rocket on the launch pad. The health diagnosis system only has 0.3 seconds to quickly diagnose the health status of the core engine: if there is something wrong with the engine, the faulty engine should be automatically shut down in an instant to ensure that the solid booster does not perform the ignition procedure.
In order to ensure foolproof, the designer equipped the rocket with three identical diagnostic systems, which can diagnose the engine state at the same time. If two or more systems diagnose faults at the same time, it is considered as engine fault. It's like a game with three referees. Only when two or more referees decide that a player has committed a foul can they be punished.
What is the difference between Liu Chang's reform and Liu Chang's reform?
Long March 6 is an all-liquid fuel rocket independently developed by China. The first and second stages adopt low temperature, non-toxic and pollution-free liquid oxygen/kerosene combination as oxidant and fuel. The original intention of the Long March 6 design is: short cycle, high speed, no pollution, low cost, commercialization and high reliability; It can launch various satellite payloads. The whole rocket adopts the "three-level" measuring and launching mode of horizontal integral testing, horizontal integral satellite-rocket docking and horizontal integral transportation and erection, and is launched by a self-propelled rocket transportation and erection vehicle, which has the conditions of being fast, clean and cheap.
Shanghai Institute of Aerospace Technology (SAST) is responsible for the overall research and development of Long March 6. Unlike Liu Chang, Liu Chang changed the rocket to "one stage and two verticals" (horizontal transfer, vertical assembly and vertical test). Previously, there was no precedent of solid-liquid combination in China's new generation of launch vehicles. The Long March 6th Project takes full advantage of the characteristics of large solid power thrust, short time, stable liquid power thrust and high specific impulse, and adopts a two-and-a-half-stage configuration with four solid boosters tied at the liquid core level to realize "cross-border cooperation" between solid and liquid power.