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HighProximity
RussiaCOSMOS 1998NORAD 19789 · launched Feb 1989Military payload
3.86kmPredicted miss distance
RussiaCOSMOS 1690NORAD 16138 · launched Oct 1985Military payload
Final forecastFinal forecast, made 13 min before the pass.
After the passBest estimate, from the orbit data published nearest its time: 3.88 km at 4 Nov 15:25 UTC.
Closest approach4 Nov 202615:25 UTC
Relative speed11.67 km/sat the closest approach
Altitude1,400 kmlow Earth orbit
Last confirmed4 Nov15:12 UTC · final forecast
Track COSMOS 1998Track COSMOS 1690All approaches
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RU COSMOS 1998 and RU COSMOS 1690 were predicted to reach a closest approach of 3.86 km at 2026-11-04 15:25 UTC, at a relative speed of 11.67 km/s. Final forecast, made 13 min before the pass. Best estimate after the pass, from the orbit data published nearest its time: 3.88 km at 4 Nov 15:25 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 1998Payload
NORAD 19789
CountryCIS
Launched1989-02-10
OrbitLEO · 1,391 × 1,415 km
COSPAR1989-009E
Maneuver capableUnknown
Profile →Globe →
COSMOS 1690Payload
NORAD 16138
CountryCIS
Launched1985-10-09
OrbitLEO · 1,381 × 1,414 km
COSPAR1985-094A
Maneuver capableUnknown
Profile →Globe →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 1400 KMISS 420Starlink 550

At 1400 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

2 predicted passes under 10 km
Pair history · COSMOS 1998 ⟷ COSMOS 1690
2026-11-04 15:253.86 km Final forecast11.67 km/s1,400 kmShown above
2026-08-11 08:083.71 km Not re-confirmed11.64 km/s1,413 kmView →

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 09:41 UTC3.88 km Best estimate4 Nov 15:25 UTC4 Nov 18:48 UTCBest estimate
4 Nov 09:33 UTC3.86 km Forecast4 Nov 15:25 UTC4 Nov 01:43 UTCRe-check
3 Nov 21:44 UTC3.87 km Forecast4 Nov 15:25 UTC3 Nov 12:29 UTCRe-check
3 Nov 21:25 UTC9.08 km Forecast4 Nov 15:25 UTC3 Nov 12:29 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
2.02 km11-11 06:57 UTC
COSMOS 1995COSMOS 1690
4.85 km11-08 10:31 UTC
COSMOS 1998COSMOS 1473
5.27 km11-04 03:45 UTC
COSMOS 1998THORAD DELTA 1 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 →