Home›Maneuver Tracker›Close Approaches›SHIYAN 27A ⟷ COSMOS 1275 DEB
HighCross-border
Final forecastFinal forecast, made minutes before the pass.
After the passBest estimate, from the orbit data published nearest its time: 5.07 km at 2 Nov 11:37 UTC.
Closest approach2 Nov 202611:37 UTC
Relative speed9.26 km/sat the closest approach
Altitude1,037 kmlow Earth orbit
Last confirmed2 Nov11:35 UTC · final forecast

CN SHIYAN 27A and RU COSMOS 1275 DEB were predicted to reach a closest approach of 5.09 km at 2026-11-02 11:37 UTC, at a relative speed of 9.26 km/s. Final forecast, made minutes before the pass. Best estimate after the pass, from the orbit data published nearest its time: 5.07 km at 2 Nov 11:37 UTC. This is a cross-border encounter between objects of different nations, the kind of event closely watched for space-security implications. 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 mattersOne side of this pass cannot maneuver, so any avoidance decision rests with the other operator. Screening continues as new element sets arrive.

The Two Objects

Dossiers from the satellite directory
SHIYAN 27APayload
NORAD 63599
CountryPRC
Launched2025-04-18
COSPAR2025-078A
Maneuver capableUnknown
NORAD 12704
CountryCIS
Launched1981-06-04
COSPAR1981-053AY
Maneuver capableNo
Uncontrolled debris fragment tracked by the public catalogue. About space debris →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 1037 KMISS 420Starlink 550

At 1037 km this pass sits inside the most congested band in low Earth orbit, home to the debris left by the 2007 ASAT test and the 2009 collision. 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 · SHIYAN 27A ⟷ COSMOS 1275 DEB
2026-11-02 11:375.09 km Final forecast9.26 km/s1,037 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
5 Nov 13:47 UTC5.07 km Best estimate2 Nov 11:37 UTC2 Nov 17:08 UTCBest estimate
2 Nov 09:14 UTC5.09 km Forecast2 Nov 11:37 UTC2 Nov 05:50 UTCRe-check
2 Nov 03:27 UTC5.09 km Forecast2 Nov 11:37 UTC1 Nov 12:08 UTCRe-check
1 Nov 19:47 UTC5.10 km Forecast2 Nov 11:37 UTC1 Nov 06:50 UTCRe-check
1 Nov 19:27 UTC6.11 km Forecast2 Nov 11:37 UTC1 Nov 06:50 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
2.83 km10-30 20:02 UTC
SHIYAN 27AOPS 0100 DEB *
4.49 km11-06 12:51 UTC
SHIYAN 27AOPS 5798 DEB
5.10 km11-04 17:36 UTC
SHIYAN 27ATHORAD AGENA D 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 →