6 Sep 2025: China launched Long March-6A with the Yaogan-40 03 triplets (65544, 65545 & 65546) from Taiyuan. According to official sources, the satellites entered the preset orbits and “will be used to carry out electromagnetic environment detection and related technical tests”. China has added 2 YG-40 triplets in 2025 (YG-40 02 launched in May), the original YG-40 launched in Sep 2023. All three launches have been from Taiyuan. The YG-40 satellites are inclined at 86.0° to allow China to monitor the Arctic and Antarctic regions, and fly in an equilateral triangle formation likely performing the radio frequency monitoring and geolocation mission. As of 11 Sep 25 the YG-40 03 triplets had begun to maneuver to establish their equilateral triangle formation. Launch Video.
– YG-40 03 deployment is following a similar pattern with both YG-40 01 and YG-40 02.
- To form the equilateral triangle formation China maneuvers 2 of the satellites to their desired operating average altitude of 851.3km. The third satellite remains at a lower SMA until it achieves the desired RAAN offset, at which point China will maneuver it to the same average altitude as the first 2 satellites and form the equilateral triangle formation.
- China increased the average altitude of YG-40 03B (65545) and 03C (65546) ~11km and both are now orbiting at 815.3km. 03B and 03C will likely continue to raise their SMA to ~851.3km to match the YG-40 01 and 02 operating orbits.
- YG-40 03A (65544) appears to be the singleton and is orbiting at 804.3km average altitude. I expect China will lower 03A’s SMA 15-20km in the coming days where it will remain for 3-4 weeks. Then it will raise its SMA to 851.3km to match 03B and 03C only it will have a RAAN offset of 0.45°- 0.60°.
14 Sep 2025: YG-40 03 orbital plane located between YG-40 01 and YG-40 02 (spaceaware.io).
14 Sep 2025: YG-40 03A remains near an average altitude of 804 km (celestrak.org).
14 Sep 2025: YG-40 03B raises its average altitude toward the 851.3 km operating orbit (celestrak.org).
14 Sep 2025: YG-40 03C raises its average altitude toward the 851.3 km operating orbit (celestrak.org).
YG-40 03 mission patch (nasaspaceflight.com).
