A Long March 4B rocket launches two Shijian 6 satellites. Credit: CASC
The 400th flight of China’s Long March rocket family deployed two classified Shijian 6 satellites into orbit Dec. 10, likely on a mission to test technology or gather signals intelligence data for the Chinese military.
The Shijian 6 satellites lifted off at 0011 GMT on Dec. 10 (7:11 p.m. EST on Dec. 9) from the Jiuquan spaceport in the Inner Mongolia region of northwestern China, according to the China Aerospace Science and Technology Corp., or CASC.
Launch occurred at 8:11 a.m. Beijing time, beginning the three-stage, liquid-fueled Long March 4B rocket’s climb into a polar orbit with the Shijian 6 satellites. The 15-story launcher took off just before sunrise and headed south to place its payloads into an orbit about 285 miles (460 kilometers) above Earth at an inclination of 97.4 degrees, according to U.S. military tracking data.
CASC, China’s largest state-owned space enterprise, said the Shijian 6 satellites will perform space environment exploration and new technology verification tests.
The new Shijian 6 satellites are the fifth such pair launched by China since 2004, and the first such mission since the fourth Shijian 6 duo lifted off in 2010. Analysts believe the earlier Shijian 6 satellites performed signals or electronic intelligence-gathering functions for the Chinese government. It wasn’t immediately clear if the new satellites, designated Shijian 6-05A and Shijian 6-05B, have a similar purpose.
Shijian means “practice” in Chinese.
The launch Dec. 10 marked the 400th flight of a Long March rocket since China deployed its first satellite into orbit on April 24, 1970. It took 37 years for China to launch its first 100 Long March rocket missions, and China has completed 300 more in less than 15 years.
The most recent 100 Long March rocket missions have launched since March 2019, a span of just two years and nine months.
The Long March rocket family consists of a fleet of launch vehicles, including the long-flying Long March 2, 3, and 4 rocket variants in service since the 1970s and 1980s.
More recently, China has debuted the Long March 5, 6, 7, 8, and 11 rockets. They span in capability from the light-class Long March 11 optimized for small satellite deliveries, to the heavy-lift Long March 5, which carried the massive core segment of China’s space station into orbit earlier this year.