At 13:40 Beijing time on September 21, 2020, a LM-4B launch vehicle lifted off from the Jiuquan Satellite Launch Center, successfully deploying the Haiyang 2C (HY-2C) satellite into orbit.This launch mission also implemented a verification test for controlling the impact zone of the first stage rocket debris by a flight based on the grid fins system.It was the second onboard flight verification test since the first successful flight test with the launch mission of LM-4B deploying GF-7 on November, 2019.Both of these two flight tests have accomplished the aim of reducing the area of first stage debris impact zone by more than 85％.