Chinese rocket researchers are working on combining the Yuanzheng 1B upper-stage vehicle and the Long March 2C for a sun-synchronous orbit mission in 2018, according to the China Academy of Launch Vehicle Technology.

China started to develop the upper-stage vehicle in the 1980s. The upper-stage vehicle is a relatively independent rocket that could restart many times in space to send different payloads to different orbits.

The first mission of the Yuanzheng upper-stage vehicle was March 30, 2015, to send a Beidou satellite into orbit after being lifted by a Long March 3C carrier rocket.

The combination of Yuanzheng and the three-stage Long March 3C has completed many missions to send the Beidou satellites into orbit.

The Long March 2C is a two-stage carrier rocket, and was previously used for sending recoverable and low-Earth-orbiting satellites into space.