Home›Maneuver Tracker›Close Approaches›COSMOS 2599 ⟷ SL-14 R/B
MediumProximity
RussiaCOSMOS 2599NORAD 66649 · launched Nov 2025Military payload
6.22kmPredicted miss distance
RussiaSL-14 R/BNORAD 20197 · launched Aug 1989Rocket body
Final forecastFinal forecast, made 18 min before the pass.
Closest approach8 Nov 202610:07 UTC
Relative speed2.51 km/sat the closest approach
Altitude1,495 kmlow Earth orbit
Last confirmed8 Nov09:49 UTC · final forecast
Track COSMOS 2599Track SL-14 R/BAll approaches
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RU COSMOS 2599 and RU SL-14 R/B were predicted to reach a closest approach of 6.22 km at 2026-11-08 10:07 UTC, at a relative speed of 2.51 km/s. Final forecast, made 18 min 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 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
COSMOS 2599Payload
NORAD 66649
CountryCIS
Launched2025-11-25
OrbitLEO · 1,482 × 1,507 km
COSPAR2025-273C
Maneuver capableUnknown
Profile →Globe →
SL-14 R/BR/B
NORAD 20197
CountryCIS
Launched1989-08-28
OrbitLEO · 1,484 × 1,523 km
COSPAR1989-068B
Maneuver capableNo
Spent rocket stage: uncontrolled, tracked by the public catalogue.
Profile →Globe →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 1495 KMISS 420Starlink 550

At 1495 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 2599 ⟷ SL-14 R/B
2026-11-08 10:076.22 km Final forecast2.51 km/s1,495 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 Nothing is overwritten: a withdrawn forecast keeps its figure, with the newer check beside it, and the best estimate after the pass is a row of its own.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
8 Nov 08:01 UTC6.22 km Forecast8 Nov 10:07 UTC8 Nov 02:44 UTCRe-check
7 Nov 12:51 UTC6.19 km Forecast8 Nov 10:07 UTC7 Nov 04:27 UTCRe-check
7 Nov 10:45 UTC6.21 km Forecast8 Nov 10:07 UTC7 Nov 01:37 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
3.28 km11-13 14:39 UTC
COSMOS 2599FENGYUN 1C DEB
3.55 km11-07 22:28 UTC
COSMOS 2599COSMOS 565
6.83 km11-09 03:29 UTC
COSMOS 2599SL-8 R/B

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 →