Home›Maneuver Tracker›Close Approaches›SDA-NG-T1TL-405 ⟷ THORAD AGENA D DEB
HighProximity
Final forecastFinal forecast, made minutes before the pass.
Closest approach13 Nov 202611:14 UTC
Relative speed13.94 km/sat the closest approach
Altitude943 kmlow Earth orbit
Last confirmed13 Nov11:14 UTC · final forecast

US SDA-NG-T1TL-405 and US THORAD AGENA D DEB were predicted to reach a closest approach of 4.65 km at 2026-11-13 11:14 UTC, at a relative speed of 13.94 km/s. Final forecast, made minutes 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
NORAD 100987
CountryUS
Launched2026-10-10
COSPAR2026-231E
Maneuver capableUnknown
NORAD 42521
CountryUS
Launched1970-04-08
COSPAR1970-025SB
Maneuver capableNo
Uncontrolled debris fragment tracked by the public catalogue. About space debris →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 943 KMISS 420Starlink 550

At 943 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

1 predicted pass under 10 km
Pair history · SDA-NG-T1TL-405 ⟷ THORAD AGENA D DEB
2026-11-13 11:144.65 km Final forecast13.94 km/s943 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 Nothing is overwritten: a withdrawn forecast keeps its figure, with the newer check beside it, and the best estimate after the pass is a row of its own.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
13 Nov 10:18 UTC4.65 km Forecast13 Nov 11:14 UTC12 Nov 17:27 UTCRe-check
13 Nov 09:58 UTC6.40 km Forecast13 Nov 11:14 UTC12 Nov 17:27 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
1.14 km11-11 10:42 UTC
SDA-NG-T1TL-405PRAETORIAN SDA_608
1.84 km11-11 10:36 UTC
SDA-NG-T1TL-405SL-16 DEB
1.90 km11-13 10:16 UTC
SDA-NG-T1TL-405FENGYUN 1C 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 →