Issue 140

Update: SJ-29A & B

3 Mar 2026: We last updated SJ-29A/B (67302 & 67303) in the 2 Feb 2026 Flash . Recall, at that time the pair had settled into GEO at 73.0°E longitude with an inclination of 3.1°. We also noted they were joined by USA 325 (51281), one of the United States’ Geosynchronous Space Situational Awareness Program (GSSAP)…

3 Mar 2026: We last updated SJ-29A/B (67302 & 67303) in the 2 Feb 2026 Flash. Recall, at that time the pair had settled into GEO at 73.0°E longitude with an inclination of 3.1°. We also noted they were joined by USA 325 (51281), one of the United States’ Geosynchronous Space Situational Awareness Program (GSSAP) satellites, which appeared to be in a favorable orbit to observe/characterize both satellites. At the time the two SJ-29 satellites were maintaining a separation of 30-70km of one another and were occasionally within 100km of USA 325.

As of 4 Mar the SJ-29-A and B continue to maintain ~50-70km absolute separation, most of this is due to in-track differences as the two satellites are nearly perfectly plane-matched. Only SJ-29B appears to have maneuvered in the past month; the satellite decreased SMA ~1km on 5 Feb and increased SMA by ~1.5km on 21 Feb. Both satellites remain IVO of 73.0° E longitude.

Based on TLE data from 28 Feb 2026 it appears USA 325 remains in the area. USA 325 has a close approach with SJ-29A as the pair travels from North to South and then has a close approach with SJ-29B as the pair travel from South to North. USA 325 has a close approach every twelve hours with one of the satellites. Close approach for SJ-29A and USA 325 occurs at ~0300Z with solar conditions favoring SJ-29A observing USA 325. Close approach between SJ-29B and USA 325 occurs 12 hours later (~1500Z), with solar conditions favoring USA 325 observing of SJ-29B. Examples: 2 Mar 2026 15:02Z SJ-29B was ~11km from USA 325 with optimal solar conditions for USA 325 to observe SJ-29B. On 4 Mar 2026 02:57Z SJ-29A was ~22km from SJ-29A with favorable solar conditions for SJ-29A to observe USA 325.


Update: SJ-29A & B

4 Mar 2026: SJ-29A orbit is just west of SJ-29B. USA 325 orbit positioned to observe both satellites with close approaches occurring every 12 hours
(saberastro.com)


Update: SJ-29A & B


Update: SJ-29A & B


4 Mar 2026: Point of Closest Approach ~22km With Optimal Lighting Conditions for SJ-29A to Observe USA 325
(saberastro.com)


Update: SJ-29A & B

2 Mar 2026: Point of Closest Approach ~11km With Optimal Lighting Conditions for USA 325 to Observe SJ-29B
(saberastro.com)