CNSA performed on September 29, 2017, classified launch of Long March 2C rocket with mysterious payload - probably another Yaogan reconnaissance satellites.
CNSA decided to launch another three reconnaissance satellites from Yaogan-30 series. Spacecrafts were delivered successfully to orbit on the top of the Long March 2C rocket from Xichang Satellite Launch Center launch site LC-03 at 04:21 UTC. This mission also is first launch since disaster of failed mission of Long March 5/ Shijian-18 from 2nd July 2017.
Due the lack of any official information regarding launch or possible designated orbit any information regarding to another Yaogan satellites comes from American tracking data provided by the Joint Space Operations Center. Satellites were placed somewhere between 593 km and 601 km orbit with inclination of 35 degrees.
According to official sources, this launch was probably success and Yaogan-30(01), (02) and (030 will perform series of “electromagnetic detection and related technical tests.” as claims CNSA in the official statement. It can be read as confirmation that satellites are in fact designated for tracking military ships and submarines as electromagnetic detection devices are often used for reconnaissance satellites. Satellites were designed and manufactured by the Chinese Academy of Sciences and are powered with deployable solar arrays with onboard batteries.
Long March 2C is a two-stage rocket designed as a modification of Dong Feng 5 ICBM. It is long for 40.4 m with diameter of 3.35 m with total mass at 223 t and LEO payload capacity of 3.8 t. Both two stages are liquid fueled with Nitrogen Tetroxide and Unsymmetrical Dimethylhydrazine. First stage is long for 35.7 m and takes over 162 t of propellant fueling YF-21B engine (basically four clustered YF-20A engines with 750 kN of thrust each) . Second stage is long for 7.58 m with 54.7 t of propellant inside tanks and powered by YF-22 central engine and four YF-23 vernier engines. Central engine is providing 742 kN of thrust while each from four vernier units is generating 10.2 kN. Long March 2C performed in total 42 launches since first performed in 1982.