After the last article, someone asked me to publish another one about the national team, so I will publish another one.
At 3:01 on February 15, 1996, the Long March 3B Y1 carrier rocket made its first flight at the Xichang Satellite Launch Center. About two seconds after ignition and take-off, the rocket’s flight attitude became abnormal. About 22 seconds later, the head of the rocket fell to the ground and hit a hillside less than 2 kilometers away from the launch pad. Then a violent explosion occurred, destroying all the rockets. The accident also killed 6 people and injured 57 people. Since the payload carried was International Communications Satellite 708, this incident also plunged my country’s external commercial launch services into a trough. After subsequent investigation and analysis, the cause of the failure was located in the change in the inertial reference of the rocket control system. The most likely failure mode causing the change in the inertial reference was the lack of current output in the power stage of the follower loop stabilization loop of the platform.
At 17:28 on August 31, 2009, the Long March 3B Y8 carrier rocket was ignited and launched from the Xichang Satellite Launch Center. The first and second stages flew normally, but the thrust of the third stage engine was low. The satellite was eventually sent into an orbit lower than the scheduled super-geosynchronous transfer orbit. After investigation and analysis, it was found that the launch abnormality was caused by a failure of the first sub-system of the rocket’s third-stage engine. The excess material blocked the hydrogen nozzle, causing local hot wires and heat flow, resulting in local leakage of the gas generator.
At 17:28 on August 18, 2011, the Long March 2C Y26 carrier rocket was ignited and lifted off at the Jiuquan Satellite Launch Center. During the flight, the secondary attitude became unstable and the launch failed. After subsequent analysis and investigation, the cause of the failure was located in the failure of the connection between the second-level cruise aircraft III extension and the servo mechanism in the second-level flight section. The reason for the connection failure was a weak link in the reliability of the connection.
At 11:26 on December 9, 2013, the Long March 4B Y10 carrier rocket failed to launch at the Taiyuan Satellite Launch Center. After subsequent investigation and analysis, it was found that the cause of the failure was a blockage in the third-stage engine, which caused its thrust to fail to reach the expected value, causing the satellite to fail to enter orbit.
At 02:55 on September 1, 2016, the Long March 4 C-Y22 carrier rocket failed to launch at the Taiyuan Satellite Launch Center. After investigation and analysis, the cause of the failure was located in the failure of the third-stage engine due to a welding defect, which resulted in abnormal operation after secondary ignition (air inclusion caused insufficient thrust).
At 11:23 on December 28, 2016, the Long March 2 Ding Y39 carrier rocket was ignited and lifted off from the Taiyuan Satellite Launch Center. 146.7 seconds after launch, the first-stage engine subsystem shut down abnormally and prematurely, resulting in a low perigee altitude of the satellite (only 210 km) after entering orbit, and a semi-major axis deviation of 157 km. In the end, the two Gaojing satellites successfully entered the scheduled 530 km SSO orbit after multiple orbit changes, but the life of the Bayi satellite was reduced from the scheduled 180 days to two months.
On June 19, 2017, the Long March 3B Y28 carrier rocket carrying the ChinaSat 9A communication satellite was ignited and launched from the Xichang Satellite Launch Center. Shortly after the satellite flew out of the earth with the rocket, it was left 16,000 kilometers above the ground due to an abnormality in the rocket. Kilometers of space, the height difference from the predetermined orbit was more than 20,000 kilometers. ChinaSat 9A then climbed more than 20,000 kilometers in space alone with its own fuel, and finally successfully settled on the predetermined orbit above the equator at 101.4° east longitude on the 16th day after launch. After investigation and analysis, the abnormal problem of the rocket was located in the thruster of the roll control of the attitude control engine in the third-stage taxiing section.
At 19:23 on July 2, 2017, the Long March 5 Y2 carrier rocket was ignited and launched at the Wenchang Space Launch Site. When it flew for 346 seconds, one engine suddenly stalled, and the other engine was still working, providing the rocket with power to accelerate its descent. As a result, the rocket’s flight formed an accelerating downward curve, and eventually crashed into the seabed, and the launch mission failed. After investigation and analysis, the cause of the failure was located in the local structural abnormality of the turbine exhaust device of one of the two YF-77 liquid hydrogen and liquid oxygen engines in the complex mechanical and thermal environment.
At 06:49 on May 23, 2019, the Long March 4 C-Y23 carrier rocket was ignited and lifted off at the Taiyuan Satellite Launch Center. The first and second stages flew normally, but the third stage worked abnormally, and the launch mission failed. Afterwards, after investigation and analysis, the cause of the accident was a quality issue with the welding seam of the third-stage engine.
At 21:34 on March 16, 2020, the Long March 7A Y1 carrier rocket encountered an abnormality during its first flight at the Wenchang Space Launch Site, and the launch mission failed. After investigation and analysis, the cause of the failure was located in the cavitation phenomenon at the outlet of the booster oxygen tank, which may have caused the pump inlet pressure to decrease and did not meet the lower limit requirements of the engine’s operation.
At 19:46 on April 9, 2020, the Long March 3B Y71 carrier rocket was ignited and launched from the Xichang Satellite Launch Center. The first and second stages flew normally, but the third stage worked abnormally, and the launch mission failed. After accident investigation, the cause of the accident was the failure of the igniter of one of the three-stage engines.
At 20:51 on March 13, 2024, the Long March 2C Y67 carrier rocket carrying DRO-A and DRO-B was ignited and lifted off at the Xichang Satellite Launch Center. The first and second stages flew normally, but the upper stage flew abnormally. The satellite did not accurately enter the intended orbit, and the launch mission failed. Finally, through emergency orbit reconstruction, after 167 days of disposal, 5 orbit control, 5 corrections, and 3 sun-lunar borrowings, the DRO-A/B combination successfully entered the DRO orbit and the binary stars separated successfully.
