Home›Maneuver Tracker›Close Approaches›OTTER 24C ⟷ FLOCK 4J-10
HighProximity
United StatesOTTER 24CNORAD 100930 · launched Oct 2026Payload
2.40kmPredicted miss distance
United StatesFLOCK 4J-10NORAD 101195 · launched Oct 2026Payload
Final forecastFinal forecast, made minutes before the pass.
After the passBest estimate, from the orbit data published nearest its time: 2.40 km at 28 Oct 11:34 UTC.
Closest approach28 Oct 202611:36 UTC
Drift speed3.9 m/s14 km/h, seen from FLOCK 4J-10
Altitude514 kmlow Earth orbit
Last confirmed28 Oct11:39 UTC · final forecast
Track OTTER 24CTrack FLOCK 4J-10All approaches
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US OTTER 24C and US FLOCK 4J-10 were predicted to reach a closest approach of 2.40 km at 2026-10-28 11:36 UTC, drifting past at about 3.9 m/s (14 km/h) as seen from FLOCK 4J-10. Final forecast, made minutes before the pass. Best estimate after the pass, from the orbit data published nearest its time: 2.40 km at 28 Oct 11:34 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
OTTER 24CPayload
NORAD 100930
CountryUS
Launched2026-10-01
OrbitLEO · 511 × 516 km
COSPAR2026-227AZ
Maneuver capableUnknown
Profile →Globe →
FLOCK 4J-10Payload
NORAD 101195
CountryUS
Launched2026-10-01
OrbitLEO · 512 × 517 km
COSPAR2026-227CY
Maneuver capableUnknown
Profile →Globe →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 514 KMISS 420Starlink 550

At 514 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

3 predicted passes under 10 km
Pair history · OTTER 24C ⟷ FLOCK 4J-10
2026-10-28 13:159.16 km Final forecast0.01 km/s517 kmView →
2026-10-28 12:413.90 km Final forecast0.01 km/s508 kmView →
2026-10-28 11:362.40 km Final forecast0.00 km/s514 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
1 Nov 08:36 UTC2.40 km Best estimate28 Oct 11:34 UTC28 Oct 14:45 UTCBest estimate
28 Oct 11:39 UTC2.40 km Forecast28 Oct 11:36 UTC28 Oct 06:44 UTCRe-check
28 Oct 07:43 UTC2.31 km Forecast28 Oct 11:41 UTC28 Oct 02:45 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
702 m10-31 16:13 UTC
STARCATCHER-1FLOCK 4J-10
948 m11-04 04:44 UTC
OTTER 24COBJECT CE
1.41 km11-03 05:48 UTC
OTTER 24CFLOCK 4J-11

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 →