Home›Maneuver Tracker›Close Approaches›SDA-NG-T1TL-402 ⟷ SL-8 R/B
HighCross-border
Final forecastFinal forecast, made 18 min before the pass.
After the passBest estimate, from the orbit data published nearest its time: 7.78 km at 30 Oct 00:29 UTC.
Closest approach30 Oct 202600:29 UTC
Relative speed14.11 km/sat the closest approach
Altitude949 kmlow Earth orbit
Last confirmed30 Oct00:11 UTC · final forecast

US SDA-NG-T1TL-402 and RU SL-8 R/B were predicted to reach a closest approach of 7.84 km at 2026-10-30 00:29 UTC, at a relative speed of 14.11 km/s. Final forecast, made 18 min before the pass. Best estimate after the pass, from the orbit data published nearest its time: 7.78 km at 30 Oct 00:29 UTC. This is a cross-border encounter between objects of different nations, the kind of event closely watched for space-security implications. 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
NORAD 100984
CountryUS
Launched2026-10-10
COSPAR2026-231B
Maneuver capableUnknown
NORAD 11681
CountryCIS
Launched1980-01-25
COSPAR1980-007B
Maneuver capableNo
Spent rocket stage: uncontrolled, tracked by the public catalogue.

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 949 KMISS 420Starlink 550

At 949 km this pass sits inside the most congested band in low Earth orbit, home to the debris left by the 2007 ASAT test and the 2009 collision. 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 · SDA-NG-T1TL-402 ⟷ SL-8 R/B
2026-11-09 11:493.88 km Live forecast14.05 km/s946 kmView →
2026-10-30 00:297.84 km Final forecast14.11 km/s949 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 19:15 UTC7.78 km Best estimate30 Oct 00:29 UTC30 Oct 08:50 UTCBest estimate
29 Oct 21:31 UTC7.84 km Forecast30 Oct 00:29 UTC29 Oct 06:35 UTCRe-check
29 Oct 00:55 UTC7.71 km Forecast30 Oct 00:29 UTC28 Oct 13:30 UTCRe-check
29 Oct 00:35 UTC9.79 km Forecast30 Oct 00:29 UTC28 Oct 13:30 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
868 m11-07 02:36 UTC
SDA-NG-T1TL-402COSMOS 1932 DEB
2.44 km11-07 01:51 UTC
SDA-NG-T1TL-402COSMOS 1275 DEB
2.68 km11-08 16:37 UTC
SDA-NG-T1TL-409SL-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 →