Issue 138

Chinese GEO Refueling Update

6 Feb 2026: As we noted in the previous flash, SJ-21 (49330) and SJ-25 (62485) exited RPO conditions in mid-January. They are now approximately 600km apart with SJ-21 located to the east of SJ-25. Both satellites have conducted minor “in-track” maneuvers (changes to their SMA) to create the separation. Of note, the two…

6 Feb 2026: As we noted in the previous flash, SJ-21 (49330) and SJ-25 (62485) exited RPO conditions in mid-January. They are now approximately 600km apart with SJ-21 located to the east of SJ-25. Both satellites have conducted minor “in-track” maneuvers (changes to their SMA) to create the separation. Of note, the two remain co-planar with a radial-track separation of <20km and a cross-track separation of only 300m. A reminder that in-track maneuvers are by far the least expensive in terms of energy (fuel). Should Chine desire to do so they could quickly and cheaply return to RPO conditions between these two satellites.

Previously, I pointed out that according to publicly available TLE data, it appeared SJ-21 and SJ-  25 conducted 7-8 extremely close (<1km) Rendezvous Proximity Operations (RPO) with one another between 1-15 January 2026.  As a reminder, TLE data is an average of multiple observations and works great when objects have adequate separation (let’s say >10km). However, once objects near one another the chances for cross-tagging and other errors grows. So, to get a more accurate understanding requires carful analysis of sensor ephemeris data. With this in mind I asked the COMSPOC OPS team to have a look with their sensor data (and to do the painstaking orbital analysis.) Their results differed from the TLE-based analysis. Based on this analysis, COMSPOC found a minimum range of approximately 2.83 km was reached on 13 Jan 2026 and the satellites were often within 5km of one another but did not perform “Zero Prox Ops” as the TLE data suggested. COMSPOC was even nice enough to create a video to show the differences between their ephemeris based analysis and that based on TLE information.



SJ-21 & SJ-25 Visualization 6 Feb 2026 (saberastro.com)

Chinese GEO Refueling Update continued


4 Jan – 6 Feb SMA Comparison (sbms.saberastro.com)


TLE Based SJ-21 & SJ-25 Proximity 1-15 January 2026 (saberastro.com)


COMSPOC vs TLE Comparison (COMSPOC_OPS)