31 Aug 2023: China launched a Long March 2D from Xichang carrying a trio of Yaogan (YG)-39 satellites. This is the first instance of the YG-39 family. Orbital parameters closely align with those of the Yaogan-35 and Yaogan-36 constellations with identical inclination and altitude. YG-39-01’s orbit is similar to YG-35-02 and YG-36-02 and may be a replacement for the YG-35-02 which had one of its three satellites fall out of formation last year. The YG-36-02 formation may also be struggling.
Launch Video.
– YG-39-01’s launch vehicle (LM-2D) and location (Xichang) matches all 10 previous YG-35 and YG-36 launches.
– The YG-39-01 orbit also matches those of YG-35 and 36 satellites with an apogee of 506kms, a perigee of 495kms and an inclination of 35 degrees.
– As with YG-35 and YG-36 triplets, YG-39-01 is matched with other YG-35 and YG-36 satellites.
– The YG-39-01 triplet (A/B/C) is grouped with YG-35-02A/B/C and YG-36-02A/B/C.
– Here are the other pairings: 1) YG-36-01 & YG-35-01; 2) YG-36-03 & YG-35-05; 3) YG-36-04 & YG-35-03; and 5) YG-36-05 & YG-35-04.
– YG-35-02 is no longer operating in formation and it
appears YG-35-02C is no longer maneuverable.
– YG-36-02 is is far more spread out than other triplets but all satellites continue to maneuver.
– YG-39-01 is continuing to develop its formation. It is likely a replacement for the failing YG-35-02 triplet.
– More broadly it appears that China is continuing to experiment with various spacing alternatives for the YG-35/36/39 satellites while also grappling with anomalies
– 4 of the 10 triplets remain in the “typical” formation (35-03/04/05 & 36-05).
– 2 of the 10 triplets (36-03 & 04) have their 3 satellites ~equally spaced with all systems maneuvering.
– 1 of the 10 (36-02) has expanded spacing between the lead vehicle and 2 trailers.
– 3 of the 10 (35-01/02 and 36-01) appear to be having problems with one of their spacecraft no longer maneuvering (35-01A, 35-02C, & 36-01B).
Yaogan-39-01 grouped in orbit with Yaogan-35-02 and Yaogan-36-02
Typical Yaogan-35/36 formation: lead, trail 1 and trail 2
Yaogan-35-02 out of formation, with Yaogan-35-02C no longer maneuvering
Yaogan-36-02 expanded formation
Yaogan-39-01 mission patch
