Issue 121

12 May: China launched a Long March-3C with TJS-19 (King of the South) (63924) from Xichang. According to official sources, the satellite has entered the planned orbit and will be “mainly used to verify multi-band and high-speed satellite communication technology” which is identical to the description provided for TJS-15 (King of the West) (63157), TJS-16 (King of the East) (63397), and TJS-17 (King of the North) (63524). On ~20 May, western observers located TJS-19 in GEO at 141.15°E. Launch Video.

– With its location at 141.15°E TJS-19 is located between TJS-9 (137.2°E) and TJS-12 (146.5°E). TJS-9 is a suspected SIGINT collection satellite while the mission of TJS-12 remains unknown.

-Initial orbit observations detected TJS-19 inclined at 4.0°, far greater than any of the other TJS “Kings.” TJS-15, 16, & 17 are all inclined 0.1°. The only TJS satellite with a greater inclination is TJS-11 (59020) which is now inclined at 4.8°.

– Of the 4 recently launched “Kings,” TJS-15 and TJS-19 appear to be operating alone, while China parked TJS-16 and TJS-17 in (relative) proximity with one another.

• In April 2025 China parked its recently launched TJS-17 in GEO at 152.74 E longitude. At this location, TJS-17 is only 0.24° east (171 km) of TJS-16 which is located at 152.50°E longitude.

– This is only the second TJS launch to use the LM-3C, the only previous use was for TJS-3 back in 2018. The LM-3C has 2 strap-on boosters and can deliver a maximum mass capacity to GTO of 3,800kg, while the LM-3B has 4 strap-on boosters capable of delivering 5,500kg to GTO.

– There was a secondary object also associated with TJS-19. The object appeared after the satellite had circularized its orbit in GEO and per the Joint Commercial Operations Cell “is possibly the apogee kick motor (AKM) which is currently drifting west at a rate of 5.14 W deg/day.”

• China used the LM-3B to launch both TJS-15 and TJS-17. In both instances observers noted a secondary object in GEO, likely an apogee kick motor.

– Speaking of TJS-15, it appears to have been visited by TJS-3 (43874) on 21 May 2025 at ~0730UTC. Minimum range between the two satellites was just over 100km and lighting conditions were ideal for TJS-3 to observe TJS-15. TJS-3 is a suspected inspection satellite. TJS-3 does not appear to have performed any specific maneuvers for this imaging opportunity. It is currently orbiting 73km above the GEO belt and drifting westward 1° per day.

https://www.youtube.com/watch?v=CCNh9Xxjrcc

TJS Summary

– TJS-19 is the 5th TJS launch in 2025, the most ever for a single year (and we’re not even to June yet). In the past 10 years China has launched 17 TJS satellites, half of which were launched in the past 18 months. For some reason China avoided the TJS-8 and TJS-18 designations…

• 2015 (1): TJS-1 (suspected SIGINT)
• 2016 (0): No Launches
• 2017 (1): TJS-2 (suspected Missile Warning)
• 2018 (1): TJS-3 (suspected satellite inspection)
• 2019 (1): TJS-4 (suspected SIGINT)
• 2020 (1): TJS-5 (suspected Missile Warning)
• 2021 (3): TJS-6 (suspected Missile Warning), TJS-7 (Unknown), & TJS-9 (suspected SIGINT)
• 2022 (0): No Launches
• 2023 (1): TJS-10 (unknown)
• 2024 (3): TJS-11 (unknown), TJS-12 (unknown), TJS-13 (HEO, suspected Missile Warning)
• 2025 (5): TJS-14 (unknown), TJS-15 (unknown), TJS-16 (unknown), TJS-17 (unknown), TJS-19 (unknown)

19 Apr – 3 May: Chinese space operators raised the average altitude for all 6 Shiyan 27 (SY-27A-F, 63599-63604) satellites to 1,045.9km. The timing of the maneuvers resulted in the nearly identical spacing between the satellites. According to official sources, the satellites “will be mainly used for space environment exploration and related technology tests”. Unknown how the even distribution of the 6 satellites around the earth will assist with accomplishing this mission.

– China launched the SY-27A-F from Taiyuan on 18 April 2025.

– Beginning on 19 Apr, China space operators began raising the average altitude of all all six satellites 39-41km. After the maneuvers were completed all 6 satellites were at an identical average altitude of 1,045.9km.

• Western observers noted the following dates for the SY-27 maneuvers: 1) SY-27D 19 Apr; 2) SY-27B 23 Apr; 3) SY-27E 24 Apr; 4) SY-27F 27 Apr; 5) SY-27A 27 Apr; and 6) SY-27C 29 Apr.

– The satellites are now virtually evenly spaced around the earth with an average separation of 7,425km between one another. The maximum deviation between separation distances is only 54km.

– The satellite spacing will remain consistent as long as China continues to keep the satellites orbiting at equal average altitudes.

11 May: China launched a Long March-6A launch with three Yaogan-40 02A-C (63918-20) satellites from the Taiyuan Satellite Launch Center. According to official sources, the satellites entered the preset orbits and “will be used to carry out electromagnetic environment detection and related technical tests”. The satellites launched into the same 86.0° inclination as the YG-40 01A-C triplets (57830-32). This inclination will allow China to monitor the Arctic and Antarctic regions. The two sets of triplets are not co-planar as the YG-40 02 satellites are offset ~72° west of YG-40 01. As of 18 May 25 the YG-40 02 triplets had begun to maneuver to establish their equilateral triangle formation. This formation indicates a likely radio frequency detection and geolocation mission. Launch Video.

-To form the equilateral triangle formation China will likely operate 2 of the satellites at an increased average altitude than the third satellite for a period of time to create the desired RAAN offset. When that has been achieved, China will maneuver the satellites to the same average altitude.

• Per Orbital Focus: “The effect of having satellites orbit at two slightly different orbit heights is that the two orbit planes move at different rates with the lower orbit moving faster. By the time the three satellites come together, the orbit of the singleton will have moved to the east of the pair at the higher altitude. “
• The YG-43 02 satellites appear to be following the same deployment pattern as YG-40 01. Two of the satellites (A & B) have increased their average altitudes equally while YG-43 02C has decreased its SMA from 802 to 78.3km beginning on 15 May.
• For YG-40-01 only one satellite maneuvered to create the formation. The singleton, YG-40-01C, increased its altitude to match YG-40A & B. (see graphic)
• YG-40 spent 60 days to complete its maneuvers and begin operating in formation.
• The YG-40 02 will likely increase their average altitude to ~850km to match that of YG-40 01. As of 19 May 2025 they had only begun their post-launch maneuvering and were at ~806km.

-Comparing with China’s YG-31 Triplets

• China also operates 4 sets of Yaogan-31 triplets. These satellites also orbit in equilateral triangle formation, however they are in a 65° inclined orbit. They are also at a higher average altitude of 1,089.2km.
• In the case of YG-31 02 A/B/C (47532, 47533, 47536), all three satellites maneuvered, the pair lowered their altitude initially and then increased their altitude. After initially raising its altitude, the singleton decreased its orbit to match the pair. As a result, YG-31 took about half the time of YG-40 01 to complete its maneuvers and begin orbiting in formation. (see graphic)

Editor’s Note: The YG-40 02 maneuvers will play out over the coming weeks, only then will we be able to confirm the techniques China has used to place the satellites into the desired formation. Stay tuned!