China News Service, August 19th, title: Demystifying the 33-year growth history of China's Long March 4 launch vehicle: Carrying capacity has been improved all the way to create multiple records

　　Author Zheng Yingying, Ma Shuaisha, Guo Chaokai

　　The Long March 4 carrier rocket "veteran" set off again.

At 6:32 on August 19th, Beijing time, China's Long March 4B carrier rocket "departed" from the Taiyuan Satellite Launch Center and rushed to space with Tianhui-2 Group 02 satellites.

Stars and arrows are all developed by the Eighth Academy of China Aerospace Science and Technology Corporation.

　　At this time, it was 33 years since the successful first flight of the Long March 4A carrier rocket on September 7, 1988.

　　The Long March 4 series of rockets are mainly responsible for the launch of sun-synchronous orbit satellites and inclined circular orbit satellites, mainly including Long March 4A (CZ-4A), Long March 4B (CZ-4B) and Long March 4C (CZ-4C) ) Type three rockets are all three-stage launch vehicles with liquid propellant at room temperature.

Long March 4A: Ten years of grinding made China the third country in the world to independently launch a sun-synchronous orbit satellite

　　The development of the Long March 4 series of rockets is closely linked to the development of China's communication satellites and meteorological satellites in the 1970s.

The Long March 4A carrier rocket has gone through ten years from its development to its first launch.

　　On September 7, 1988, the Long March 4A carrier rocket won its first battle. At the Taiyuan Satellite Launch Center, the Fengyun-1 meteorological satellite was put into a predetermined orbit, setting a new record for the first successful flight of China's large-scale carrier rocket; making China the world The third country to independently launch a sun-synchronous orbit satellite; the first-stage YF-21B engine was the liquid rocket engine with the largest thrust in China at that time.

Data map, at 15:27 on April 30, 2021, the Long March 4 Bingyao 34 carrier rocket was launched.

Photo courtesy of the Eighth Academy of China Aerospace Science and Technology Corporation

Long March No. 4 B/C: Carrying capacity is improved all the way, the first room temperature propellant three-stage engine secondary starting technology

　　On the basis of the Long March 4A carrier rocket, Shanghai Aerospace has developed the Long March 4B and Long March 4C carrier rockets.

　　On May 10, 1999, the Long March 4B carrier rocket successfully flew for the first time at the Taiyuan Satellite Launch Center.

Compared with the Long March 4A launch vehicle, the Long March 4B launch vehicle has made a number of technical improvements to further improve the rocket carrying capacity; a new long-range integrated test launch device has been developed, and the integration of a launch vehicle has been realized for the first time in China Long-distance test launch control has raised the test launch technology of China's carrier rocket to a new level.

　　In the late 1990s, with the continuous increase of satellite platforms, the Long March 4B launch vehicle faced an urgent need to improve its carrying capacity.

In March 1999, Shanghai Aerospace launched the development of the Long March 4B modified rocket. The third stage adopts a two-start operation method to achieve a substantial increase in its 700km sun-synchronous orbit carrying capacity; at the same time, it improves the rocket's ability to launch multiple satellites with one arrow. , To meet the launch needs of more types of satellites.

On April 27, 2006, the CZ-4B rocket with three stages and two launches successfully flew at the Taiyuan Satellite Launch Center. The remote sensing satellite No. 1 was launched, starting the journey of catching up with the sun.

In April 2007, China Aerospace Science and Technology Corporation approved the naming of the Long March 4B rocket, which uses the three-stage two-start technology state, as the Long March 4C carrier rocket (CZ-4C).

　　In May 2018, it was the Long March 4C carrier rocket that successfully sent the "Queqiao" relay satellite of the Chinese lunar exploration project Chang'e-4 mission into the scheduled orbit at the Xichang Satellite Launch Center.

So far, the Long March 4 series rockets have new skills for launching missions in Taiyuan, Jiuquan, and Xichang, China.

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