Home›Maneuver Tracker›Close Approaches›COSMOS 2151 ⟷ OBJECT K
HighProximity
RussiaCOSMOS 2151NORAD 21422 · launched Jun 1991Military payload
2.80kmPredicted miss distance
SKOROBJECT KNORAD 100964 · launched Oct 2026Payload
Final forecastFinal forecast, made 18 min before the pass.
After the passBest estimate, from the orbit data published nearest its time: 2.81 km at 29 Oct 21:49 UTC.
Closest approach29 Oct 202621:49 UTC
Relative speed15.15 km/sat the closest approach
Altitude561 kmlow Earth orbit
Last confirmed29 Oct21:31 UTC · final forecast
Track COSMOS 2151Track OBJECT KAll approaches
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RU COSMOS 2151 and SKOR OBJECT K were predicted to reach a closest approach of 2.80 km at 2026-10-29 21:49 UTC, at a relative speed of 15.15 km/s. Final forecast, made 18 min before the pass. Best estimate after the pass, from the orbit data published nearest its time: 2.81 km at 29 Oct 21:49 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 2151Payload
NORAD 21422
CountryCIS
Launched1991-06-13
OrbitLEO · 556 × 573 km
COSPAR1991-042A
Maneuver capableUnknown
Profile →Globe →
OBJECT KPayload
NORAD 100964
CountrySKOR
Launched2026-10-07
OrbitLEO · 564 × 581 km
COSPAR2026-229K
Maneuver capableUnknown
Profile →Globe →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 561 KMISS 420Starlink 550

At 561 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 2151 ⟷ OBJECT K
2026-10-29 21:492.80 km Final forecast15.15 km/s561 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
2 Nov 16:55 UTC2.81 km Best estimate29 Oct 21:49 UTC29 Oct 21:27 UTCBest estimate
29 Oct 21:31 UTC2.80 km Forecast29 Oct 21:49 UTC29 Oct 05:26 UTCRe-check
29 Oct 00:15 UTC2.78 km Forecast29 Oct 21:49 UTC28 Oct 13:22 UTCRe-check
28 Oct 22:15 UTC2.76 km Forecast29 Oct 21:49 UTC27 Oct 21:22 UTCRe-check
28 Oct 21:55 UTC3.31 km Forecast29 Oct 21:49 UTC27 Oct 21:22 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
487 m10-27 21:46 UTC
COSMOS 2151LEMUR-2-LUCILLE-ROSE
991 m10-27 11:23 UTC
COSMOS 2151CZ-2C DEB
1.36 km11-03 02:07 UTC
SHIJIAN 6 05A (SJ-6 05A)OBJECT K

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 →

Cite this encounter: Orbital Radar — “COSMOS 2151 ⟷ OBJECT K: 2.80 km predicted close approach”, https://orbitalradar.com/conjunction/100964-21422 (accessed 2026-11-03).