Issue 147

SJ-29A/B conduct synchronized maneuvers

A paired Shijian-29 test system has tightened its formation in the geostationary belt to roughly 30–35 km — the closest the two have flown — while the U.S. inspector USA 324 maneuvers to keep both in view.

Author

Greg Gillinger

Collaborators & Sources

Saber Astronautics · CelesTrak · COMSPOC

Published

14 Jun 2026 · 9-min read

Since arriving in the geostationary belt in early January, Shijian-29A and -29B have held station near 73°E, drifting in and out of a loose 10–90 km formation. Over the first week of June the pair executed a coordinated set of burns that narrowed their separation to about 30–35 km and synchronized their longitudinal drift — the tightest, most deliberate formation the system has shown to dat

0255075100 2 Jun5 Jun8 Jun11 Jun14 Jun SEPARATION (km) ~35 km · 8 Jun burn pair SJ-29A / SJ-29B — pairwise separation
Fig. 1 — Pairwise separation of SJ-29A/B, 2–14 Jun 2026. Source: Saber Astronautics, CelesTrak.

Element-set histories show both objects adjusting semi-major axis within hours of one another — behavior consistent with a planned, jointly commanded maneuver rather than independent station-keeping. The timing, direction, and magnitude of the burns line up too closely to be coincidental.

Assessment

The synchronization suggests SJ-29A/B is rehearsing cooperative proximity operations. Two spacecraft holding a controlled, close formation is a prerequisite for inspection, servicing, or coordinated RPO against a third object — a capability with obvious dual-use implications.

The maneuver did not go unobserved. USA 324, a U.S. geostationary inspector, shifted longitude in the days that followed to hold a viewing geometry on the pair, settling into a position roughly one degree west.

GEO longitude band — 9 Jun 2026 68°E71°E74°E77°E SJ-29A/B · 73.3°E USA 324 Schematic — relative GEO longitudes, not to scale
Fig. 2 — Relative GEO longitudes of SJ-29A/B and USA 324 on 9 Jun. Schematic; not to scale.

Orbital parameters — SJ-29A (9 Jun 2026)

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Table 1 — Observed maneuver sequence, early June 2026.
DateObjectΔa (km)Resulting sep. (km)
5 JunSJ-29B+12~70
7 JunSJ-29A−9~48
8 JunSJ-29A/Bpaired~35

Whether SJ-29A/B is working toward inspection of a partner satellite, a docking demonstration, or simply maturing the guidance needed to fly close formations, the trend line is clear: each pass tightens, and each maneuver is better coordinated than the last. The Flash will track the pair’s separation through the next station-keeping cycle.