Home›Maneuver Tracker›Close Approaches›YAOGAN-39 04C ⟷ SJ-30C
HighProximity
ChinaYAOGAN-39 04CNORAD 58145 · launched Oct 2023Military payload
1.63kmPredicted miss distance
ChinaSJ-30CNORAD 66547 · launched Nov 2025Military payload
Final forecastFinal forecast, made minutes before the pass.
Closest approach13 Nov 202608:14 UTC
Relative speed4.24 km/sat the closest approach
Altitude509 kmlow Earth orbit
Last confirmed13 Nov08:13 UTC · final forecast
Track YAOGAN-39 04CTrack SJ-30CAll approaches
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CN YAOGAN-39 04C and CN SJ-30C were predicted to reach a closest approach of 1.63 km at 2026-11-13 08:14 UTC, at a relative speed of 4.24 km/s. Final forecast, made minutes before the pass. Miss distance and time of closest approach are computed by propagating the latest published orbital elements for both objects, and each pass is re-checked every 20 minutes as new element sets are published. See the Satellite Maneuver Tracker for the live picture and space situational awareness for context.

Why it mattersBoth objects are catalogued as payloads. Screening continues as new element sets arrive; operators act on their own conjunction data.

The Two Objects

Dossiers from the satellite directory
YAOGAN-39 04CPayload
NORAD 58145
CountryPRC
Launched2023-10-23
OrbitLEO · 514 × 515 km
COSPAR2023-163E
Maneuver capableUnknown
Profile →Globe →
SJ-30CPayload
NORAD 66547
CountryPRC
Launched2025-11-19
OrbitLEO · 514 × 524 km
COSPAR2025-266C
Maneuver capableUnknown
Profile →Globe →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 509 KMISS 420Starlink 550

At 509 km this pass sits in low Earth orbit. Objects here stay up for decades: there is too little atmospheric drag to clean the band naturally. Why crowded bands matter →

History Between This Pair

1 predicted pass under 10 km
Pair history · YAOGAN-39 04C ⟷ SJ-30C
2026-11-13 08:141.63 km Final forecast4.24 km/s509 kmShown above

Repeat encounters are common for objects in near-intersecting orbital planes. Each pass is re-screened as fresh element sets arrive; "Final forecast" means the screening still predicted it within 45 minutes of its time, "Not re-confirmed" means later screening stopped finding it.

Forecast Record

Every figure published for the pass shown above, newest first. Nothing is overwritten: a withdrawn forecast keeps its figure, with the newer check beside it, and the best estimate after the pass is a row of its own.
Computed · figure · predicted time · orbit data · by
13 Nov 05:33 UTC1.63 km Forecast13 Nov 08:14 UTC12 Nov 17:47 UTCRe-check
12 Nov 23:01 UTC1.64 km Forecast13 Nov 08:14 UTC12 Nov 17:47 UTCRe-check
12 Nov 19:13 UTC1.89 km Forecast13 Nov 08:14 UTC12 Nov 06:43 UTCRe-check
12 Nov 09:12 UTC2.10 km Forecast13 Nov 08:14 UTC12 Nov 00:18 UTCRe-check
12 Nov 08:38 UTC2.24 km Forecast13 Nov 08:14 UTC11 Nov 14:50 UTCRe-check
12 Nov 08:18 UTC2.44 km Forecast13 Nov 08:14 UTC11 Nov 14:50 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
1.18 km11-08 06:00 UTC
SJ-30CERMINAZ-2U
1.27 km11-06 17:33 UTC
SJ-30CREASON-1
2.15 km11-10 17:14 UTC
YAOGAN-39 04CCOSMOS 2251 DEB

How These Numbers Are Computed

Miss distance and TCA come from propagating the latest published orbital elements for both objects and searching for the minimum separation over the screening window. Element sets carry kilometre-scale uncertainty, so figures here describe a close pass, not a collision prediction; a change in either object's published elements re-computes the pass automatically. What is a conjunction? → How conjunction assessment works →