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MediumProximity
RussiaCOSMOS 2146NORAD 21302 · launched May 1991Military payload
6.08kmPredicted miss distance
RussiaCOSMOS 909NORAD 10010 · launched May 1977Military payload
Final forecastFinal forecast, made 6 min before the pass.
After the passBest estimate, from the orbit data published nearest its time: 6.02 km at 1 Nov 17:46 UTC.
Closest approach1 Nov 202617:46 UTC
Relative speed9.65 km/sat the closest approach
Altitude1,389 kmlow Earth orbit
Last confirmed1 Nov17:40 UTC · final forecast
Track COSMOS 2146Track COSMOS 909All approaches
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RU COSMOS 2146 and RU COSMOS 909 were predicted to reach a closest approach of 6.08 km at 2026-11-01 17:46 UTC, at a relative speed of 9.65 km/s. Final forecast, made 6 min before the pass. Best estimate after the pass, from the orbit data published nearest its time: 6.02 km at 1 Nov 17:46 UTC. 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
COSMOS 2146Payload
NORAD 21302
CountryCIS
Launched1991-05-16
OrbitLEO · 1,391 × 1,418 km
COSPAR1991-033D
Maneuver capableUnknown
Profile →Globe →
COSMOS 909Payload
NORAD 10010
CountryCIS
Launched1977-05-19
OrbitMEO · 989 × 2,107 km
COSPAR1977-036A
Maneuver capableUnknown
Profile →Globe →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 1389 KMISS 420Starlink 550

At 1389 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 · COSMOS 2146 ⟷ COSMOS 909
2026-11-01 17:466.08 km Final forecast9.65 km/s1,389 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
4 Nov 18:38 UTC6.02 km Best estimate1 Nov 17:46 UTC1 Nov 17:22 UTCBest estimate
1 Nov 09:16 UTC6.08 km Forecast1 Nov 17:46 UTC1 Nov 05:39 UTCRe-check
31 Oct 21:16 UTC6.16 km Forecast1 Nov 17:46 UTC31 Oct 08:12 UTCRe-check
31 Oct 18:16 UTC6.17 km Forecast1 Nov 17:46 UTC31 Oct 00:24 UTCRe-check
31 Oct 17:56 UTC6.90 km Forecast1 Nov 17:46 UTC31 Oct 00:24 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
4.63 km10-30 01:49 UTC
COSMOS 2146GLOBALSTAR M089
6.72 km11-02 23:57 UTC
COSMOS 2146COSMOS 1831
6.80 km11-03 11:49 UTC
COSMOS 2146SL-14 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 →