Issue 137

China: Shiyan-12 01 Reverses Course

12 Jan 2026: It’s that time again. China increased the average altitude of its SY-12 01 (50321) inspector satellite ~91km. As a result the satellite changed from drifting East 0.6° per day and is now drifting westward 0.6° per day. China made the maneuver as SY-12 01 approached 170°E, previously China had allowed the…

12 Jan 2026: It’s that time again. China increased the average altitude of its SY-12 01 (50321) inspector satellite ~91km. As a result the satellite changed from drifting East 0.6° per day and is now drifting westward 0.6° per day. China made the maneuver as SY-12 01 approached 170°E, previously China had allowed the satellite to move as far east as 178°E. If China maintains previous patterns, SY-12 01 will drift westward for the next 8-9 months and reverse course when it arrives at 16-19°E longitude. Average leg for SY-12 satellites is 244 days.


2.5 Yrs of SY-12 01 Orbital History: Average Altitude (black) and Longitude Location (Green)
(celestrak.org)

China launched the SY-12 01 and SY-12 02 satellites on 23 Dec 2021. This is SY-12 01’s 6th change of direction. SY-12 02 has changed direction 5 times.

SY-12 02 most recently changed directions on 13 July 2025 when it increased its average altitude to begin drifting Westward. SY-12 02 will likely reverse course in mid-March 2026.

– On average the two SY-12 satellites cover from 17.8°E to 175.1°E during each leg of their journey. Average time for each leg has been 244 days.