China launches new set of Yaogan-40 satellites into polar orbit

HELSINKI — China added a third trio of spacecraft to a group of remote sensing satellites Saturday, marking the country’s 52nd launch of the year.

A Long March 6A rocket lifted off at 12:34 p.m. Eastern (1634 UTC) Sept. 6 from Taiyuan Satellite Launch Center, North China. The Shanghai Academy of Spaceflight Technology (SAST) under state-owned space contractor CASC announced complete success of the mission around an hour after liftoff, revealing the payload to be Yaogan-40 (03) satellites. 

The satellites will carry out electromagnetic environment detection and related technical tests, according to SAST, using the typical opaque description for such missions. The DFH Satellite Co., Ltd under CASC’s China Academy of Space Technology (CAST) stated that it developed the spacecraft, providing no further details.

While U.S. space domain awareness had not cataloged the satellites at time of reporting, the Yaogan-40 (03) group could join the earlier two groups—launched in September 2023 and May 2025 respectively—in near-circular 850-kilometer-altitude orbits inclined by 86 degrees. Navigation warnings issued ahead of launch indicate a launch into near-polar orbit.

Analysis by ISR University shows the earlier Yaogan-40 groups to be in equilateral triangle formations, following orbit-raising maneuvers, and likely designed to perform radio frequency monitoring and geolocation tasks, including over polar regions.

Yaogan (“remote sensing”) satellites are thought to be for users including military customers, with uses thought to include optical imaging, synthetic aperture radar (SAR) and electronic intelligence (ELINT) satellites.

Few details, if any, are available about the satellites. They are typically described as being for purposes including land survey, crop yield estimation, environmental management, meteorological warning and forecasting, and disaster prevention and reduction or “electromagnetic environment detection and related tests.”

The Saturday mission was China’s 52nd orbital launch of the year, keeping it on course to surpass a national record of 68 launches in a calendar year, set in 2024. This number includes one failure, suffered by commercial launch service provider Landspace in August.

Chinese launch activity updates

The launch follows launches on Thursday and Friday of a Long March 3C carrying the experimental Shiyan-29, and a commercial Ceres-1 rocket carrying three satellites.

U.S. Space Force tracking shows Shiyan-29 in a 35,796 x 36,586-km, 29 degree inclined geosynchronous drift orbit. s2a systems also spotted the spacecraft, as well as a tumbling third stage from the launch.

Chinese launch activity is set to continue in the coming days, with an expected sea launch from the Dongfang Hangtiangang barge from the Yellow Sea Sept. 8, likely seeing a Jielong-3 solid rocket launch a new set of spacecraft for GeeSpace, the space arm of automaker Geely. Meanwhile, a Long March 7A rocket has been rolled out at Wenchang Satellite Launch Center on Hainan island, with launch of an undisclosed payload expected around Sept. 9.