YF-77, the first stage main engine of Chang 5-2 rocket core, stopped due to the failure of turbopump pressure relief, thus losing the effective thrust of the first stage flight segment, which eventually led to the failure of rocket launch.

Long March 5 series launch vehicles;

Also known as "Big Rocket" and "Ice Arrow", it is a one-off large-scale cryogenic liquid launch vehicle developed by People's Republic of China (PRC) in 2006 to meet the needs of the further development of space and make up for the gap between China and foreign countries. It is also the core rocket series with a diameter of 5 meters in China's new generation of launch vehicles.

The Long March 5 series was developed by China Aerospace Science and Technology Corporation, and the design adopted the idea of generalization, serialization and combination. This series consists of a two-stage semi-configured basic Long March V carrier rocket (code: CZ-5) and a first-stage semi-configured Long March V B carrier rocket without a second stage (code: CZ-5B), and its carrying capacity will reach geosynchronous transfer orbit 13 tons and low-earth orbit 23 tons respectively. The rocket series will be used for the future construction of China's?Tiangong?space station, the third phase of the lunar exploration project and other deep space exploration.

From April 2065438 to August 2005, the secondary power supply system of Long March 5 core was successfully put into trial operation for the second time. 165438+1On October 23rd, the Long March V carrier rocket practiced its arrows together and successfully completed the transition.