Issue 131

China: SY-29 Update

9 Oct 2025: China reduced the average altitude of its SY-29 (65486) satellite to 35,785.5km or just below GEO (35,786km). China launched SY-29 on 5 Sep 2025 and its original orbit was ~400km above the GEO graveyard orbit resulting in a westward drift of ~5.5°/day. Beginning in late September China conducted a series of…

9 Oct 2025: China reduced the average altitude of its SY-29 (65486) satellite to 35,785.5km or just below GEO (35,786km). China launched SY-29 on 5 Sep 2025 and its original orbit was ~400km above the GEO graveyard orbit resulting in a westward drift of ~5.5°/day. Beginning in late September China conducted a series of three maneuvers. The first occurred 28-29 Sep when China decreased SY-29’s SMA (average altitude) ~55km. On 30 Sep, China reduced SY-29’s SMA another 290km and decreased its westward drift to 0.725°/day. The final maneuver occurred on 6 Oct when China further reduced SY-29’s SMA another ~55km. This final maneuver centered SY-29’s orbit over 95.1° E longitude with a minimal eastward drift of 0.01°/day. The satellite remains 28.5° inclined. With these maneuvers SY-29 is likely NOT some sort of GEO inspection satellite and is intended for other experimentation.