A Long March 3B rocket lifted-off from the Xichang Satellite Launch Center, Peoples Republic of China, at 2120 GMT, 22 September 2019, carry two satellites for the Chinese satellite navigation system – Beidou. The satellites involved in this mission were BEIDOU-3 M23 and M24. As with the case for all other third-generation MEO (Medium Earth Orbit), Beidou launches the Long March 3B variant utilised the YZ-1 Upper Stage.

This was the fourth launch in service of the Beidou constellation this year, but the first catering to the MEO segment.