The second satellite launch attempt on April 24, 1970, was successful. A CZ-1 was used to launch the 173 kg "Dong Fang Hong I" (东方红一号, meaning The East Is Red I), also known as "Mao-1". It was the heaviest first satellite placed into orbit by a nation, exceeding the combined masses of the first satellites of the other four previous countries. The third stage of the CZ-1 was specially equipped with a 40 m2 solar reflector (观察球) deployed by the centrifugal force developed by the spin-up orbital insertion solid propellant stage. Therefore, the faint magnitude 5 to 8 brightness of the DFH-1 made the satellite (at best) barely visible with naked eyes was consequently dramatically increased to a comfortable magnitude 2 to 3. The PRC's second satellite was launched with the last of the CZ-1 SLVs on March 3, 1971. The 221 kg ShiJian-1 (SJ-1) was equipped with a magnetometer and cosmic-ray/x-ray detectors. The first crewed space program was known as "Project 714", was officially adopted in April 1971 with the goal of sending two astronauts into space by 1973 aboard the Shuguang spacecraft. The first screening process for astronauts had already ended on March 15, 1971, with 19 astronauts chosen. The program would soon be cancelled due to political turmoil. A first flight test of the DF-5 ICBM was carried out in October 1971. On August 10, 1972, the new heavy-lift SLV FB-1 made its maiden test flight, with only partial success. The CZ-2A launcher, originally designed to carry the Shuguang-1 spacecraft, was first tested on November 5, 1974, carrying China's first FSW-0 recoverable satellite, but failed. After some redesign work, the modified CZ-2C successfully launched the FSW-0 No.1 recoverable satellite (返回式卫星) into orbit on November 26, 1975. After expansion, the Northern Missile Test Site was upgraded as a test base in January 1976 to become the Northern Missile Test Base (华北导弹试验基地) known as Base 25.