On this day, 51 years ago, August 1, 1974 (June 14, 1974 in the lunar calendar), nuclear-powered submarines were officially equipped with the Navy. On August 1, 1974, the Central Military Commission issued an order to name the first nuclear-powered submarine designed and manufactured by China itself "Long March 1" and incorporate it into the naval combat sequence. On the same day, the Central Military Commission held a solemn flag awarding ceremony for the submarine. Navy Commander Xiao Jinguang, Deputy Director of the National Defense Science and Technology Commission Qian Xuesen and others attended the submarine handover and naming conference. Since then, the People's Navy has entered a new stage of possessing nuclear submarines. This nuclear submarine was completed and launched on December 26, 1970.