Home›Maneuver Tracker›Close Approaches›COSMOS 2491 ⟷ SL-8 DEB
MediumProximity
RussiaCOSMOS 2491NORAD 39497 · launched Dec 2013Military payload
5.53kmPredicted miss distance
RussiaSL-8 DEBNORAD 21209 · launched Feb 1991Debris
Live forecastConfirmed by the latest screening, 21 Oct 17:31 UTC.
Closest approach22 Oct 202615:56 UTC
Relative speed13.99 km/sat the closest approach
Altitude1,484 kmlow Earth orbit
Separation now—live
Track COSMOS 2491Track SL-8 DEBAll approaches
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RU COSMOS 2491 and RU SL-8 DEB are predicted to reach a closest approach of 5.53 km at 2026-10-22 15:56 UTC, at a relative speed of 13.99 km/s. Confirmed by the latest screening, 21 Oct 17:31 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 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 2491Payload
NORAD 39497
CountryCIS
Launched2013-12-25
OrbitLEO · 1,481 × 1,502 km
COSPAR2013-076E
Maneuver capableUnknown
Profile →Globe →
SL-8 DEBDebris
NORAD 21209
CountryCIS
Launched1991-02-12
OrbitLEO · 1,469 × 1,684 km
COSPAR1991-009BC
Maneuver capableNo
Uncontrolled debris fragment tracked by the public catalogue. About space debris →
Profile →Globe →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 1484 KMISS 420Starlink 550

At 1484 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 2491 ⟷ SL-8 DEB
2026-10-22 15:565.53 km Live forecast13.99 km/s1,484 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 Nothing is overwritten: a withdrawn forecast keeps its figure, with the newer check beside it, and the best estimate after the pass is a row of its own.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
21 Oct 16:30 UTC5.53 km Forecast22 Oct 15:56 UTC21 Oct 06:57 UTCRe-check
21 Oct 16:10 UTC9.12 km Forecast22 Oct 15:56 UTC21 Oct 06:57 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
1.59 km10-22 05:56 UTC
COSMOS 2491DELTA 1 DEB
1.75 km10-22 11:58 UTC
COSMOS 2491GONETS M 06
3.07 km10-22 12:56 UTC
COSMOS 2491GONETS M 06

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 2491 ⟷ SL-8 DEB: 5.53 km predicted close approach”, https://orbitalradar.com/conjunction/21209-39497 (accessed 2026-10-21).