China launched a Long March 2C rocket with three Yaogan 30 military satellites on Friday and tested new lattice fins on the first stage of the Long March to channel the booster away from the populated areas.
The Two-Stage Rocket Launched Friday, March 23 (EDT: 23.57 EDT), the rocket will launch at 0357 GMT from Xichang Space Center in Sichuan Province, China, on March 2, according to the China Academy of Launch Vehicle Technology.
The launch took place on Friday, Beijing time, at 11:57.
The tracking data released by the US military showed that the Long March 2C rocket had an orbit of 600 kilometers with a 35 degree inclination to the equator. The orbit is similar to that of four of the earlier Yaogan 30 triplets in late 2017 and early 2018, which also flew into space onboard Long March 2C rockets from Xichang. Satellites – called Yaogan 30-05 – remain a mystery. According to Chinese state media, spacecraft are designed for "remote sensing missions" and are "used to detect electromagnetic environments and related technological tests."
It is believed that the Yaogan satellite series is operated by the Chinese military for intelligence purposes.
Some analysts suggested that the 12 Yaogan satellites 30-01, 30-02, 30-03 and 30-04, launched in 2017 and 2018, could test new electronic listening devices or help the Chinese military, the US to track and other missions abroad.
However, the Chinese government has not disclosed details of the spacecraft and its missions.
China's military has another satellite called Yaogan 30, which is, however, in a polar orbit and is considered high-resolution imaging spacecraft.
Images of the Long March 2C rocket launched on Friday showed air surfaces attached to the intermediate stage structure on the first stage booster.  The fins did not fly on previous missions in March, and their appearance is similar to the lattice fins flying on SpaceX's Falcon rocket boosters.
In a statement after the launch, the Chinese launch authorities said the mission had tested the function of the new aerodynamics control surfaces in support of controlling the booster on descent.
The new system is used to control where the booster falls back to the ground. Rockets fired from China's inland ports usually drop their stages and still contain toxic propellant vapors near villages and towns.
E-mail to the author.
Follow Stephen Clark on Twitter: @ StephenClark1 .