Abstract:  As China’s only manned launch vehicle, the LM-2F Launch vehicle successfully launched the Shenzhou 12 manned spacecraft into its predetermined orbit on June 12, 2021, signifying the successful completion of the first manned launch mission in the construction and key technology test stage of China Space Station (CSS). From the launch of the Shenzhou 11 manned spacecraft on October 12, 2016 to the launch of Shenzhou 12 in 2021, over the past five years, the LM-2F launch vehicle has been continuously improved in terms of product reliability through technological innovation and design improvement, and its flight reliability index has increased from 0.97 to 0.98. Based on the new launch mission requirements for the construction stage of CSS, this paper introduces the technological innovation and reliability improvement methods of the LM-2F from the aspects of design improvement, research methods and process optimization. The LM-2F launch vehicle will make greater contributions in supporting the construction of CSS with higher reliability and perfect launch success rate.

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