Issue 69

March Madness: SJ-23 comes within 4km of TL-1-03

18 Mar 2023: It appears SJ-23 had a Point of Closest Approach (POCA) of 3.537kms with the Chinese Relay Satellite TL-1-03: 3.537 km on 18 Mar 2023 at 16:38:42 UTC. Information courtesy of the Palski Space Domain Awareness Report. - Based on catalog information, SJ-23 did not have to execute many maneuvers to actually achieve that POCA. U…

18 Mar 2023: It appears SJ-23 had a Point of Closest Approach (POCA) of 3.537kms with the

Chinese Relay Satellite TL-1-03: 3.537 km on 18 Mar 2023 at 16:38:42 UTC. Information

courtesy of the Palski Space Domain Awareness Report.

– Based on catalog information, SJ-23 did not have to execute many maneuvers to actually achieve that POCA. Upon SJ-23's relocation to GEO from its insertion orbit, it was already on the trajectory needed to reach that POCA with Tianlian 1-03. Given the proximity it is likely this was intentional. -It does appear (based on 18 SDS GP data), that both satellites may have maneuvered just prior to the predicted close approach. – That might suggest the close approach was planned, or the two operators were not talking and conducted a maneuver to increase miss distance. – It is possible that the observations were mis-associated due to the proximity. -SJ-23 continued to drift West until it was .9° away from TL-1-03. On 22 Mar ~13:13:09UTC, SJ- 23 decreased SMA 15.6km reversing it's drift. SJ-23 is now 3km beneath the GEO belt and slowly drifting eastward back toward TL-1-03. At current SMAs the two spacecraft will again be in proximity on 9 Apr. -China launched Shijian-23 on 9 Jan 2023 from Wenchang using a LM-7A. Launch Video. -Shijian-23, released a small object on ~19 Jan 2023. SJ-23 was initially thought of as a likely follow-on to SJ-13, a communications satellite. However, the release of a sub-payload is more indicative of SJ-17, TJS-3 and SJ-21.

Dancing in GEO: SJ-23 and

TL-1-03

Possible SJ-23 Maneuver Observed 17 Mar 15:07:42UTC

Possible TL-1-03 Maneuver Observed 17 Mar 05:57:42UTC

SJ-23 Reverses to Eastward Drift

Observed 22 Mar ~13:13:09UTC

SJ-23 & TL-1-03 at POCA via Slingshot

Visualization Tool

March Madness: SJ-23 comes within 4km of TL-1-03

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