Home›Maneuver Tracker›Close Approaches›STARCATCHER-1 ⟷ FLOCK 4J-12
HighProximity
United StatesSTARCATCHER-1NORAD 100921 · launched Oct 2026Payload
1.19kmPredicted miss distance
United StatesFLOCK 4J-12NORAD 101287 · launched Oct 2026Payload
Final forecastFinal forecast, made 12 min before the pass.
Closest approach11 Nov 202620:09 UTC
Drift speed1.8 m/s6 km/h, seen from FLOCK 4J-12
Altitude506 kmlow Earth orbit
Last confirmed11 Nov19:57 UTC · final forecast
Track STARCATCHER-1Track FLOCK 4J-12All approaches
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US STARCATCHER-1 and US FLOCK 4J-12 were predicted to reach a closest approach of 1.19 km at 2026-11-11 20:09 UTC, drifting past at about 1.8 m/s (6 km/h) as seen from FLOCK 4J-12. Final forecast, made 12 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 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
STARCATCHER-1Payload
NORAD 100921
CountryUS
Launched2026-10-01
OrbitLEO · 511 × 515 km
COSPAR2026-227AQ
Maneuver capableUnknown
Profile →Globe →
FLOCK 4J-12Payload
NORAD 101287
CountryUS
Launched2026-10-01
OrbitLEO · 511 × 517 km
COSPAR2026-227DA
Maneuver capableUnknown
Profile →Globe →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 506 KMISS 420Starlink 550

At 506 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

5 predicted passes under 10 km
Pair history · STARCATCHER-1 ⟷ FLOCK 4J-12
2026-11-11 22:029.06 km Final forecast0.01 km/s508 kmView →
2026-11-11 21:178.71 km Final forecast0.01 km/s521 kmView →
2026-11-11 20:412.23 km Final forecast0.00 km/s518 kmView →
2026-11-11 20:091.19 km Final forecast0.00 km/s506 kmShown above
2026-11-11 18:286.78 km Withdrawn0.01 km/s509 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
11 Nov 17:37 UTC1.19 km Forecast11 Nov 20:09 UTC11 Nov 12:47 UTCRe-check
11 Nov 10:26 UTC1.17 km Forecast11 Nov 20:08 UTC11 Nov 04:05 UTCRe-check
11 Nov 04:26 UTC2.50 km Forecast11 Nov 19:35 UTC11 Nov 00:48 UTCRe-check
10 Nov 20:46 UTC2.62 km Forecast11 Nov 19:32 UTC10 Nov 16:47 UTCRe-check
10 Nov 19:46 UTC2.59 km Forecast11 Nov 19:32 UTC10 Nov 05:56 UTCRe-check
10 Nov 19:26 UTC3.08 km Forecast11 Nov 19:26 UTC10 Nov 05:56 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
365 m11-09 20:38 UTC
OTTER 24CFLOCK 4J-12
365 m11-09 20:38 UTC
OTTER 24CFLOCK 4J-12
906 m11-13 07:10 UTC
STARCATCHER-1LUNA-2

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 →