Home›Maneuver Tracker›Close Approaches›R5-S9 ⟷ AAC-IO1
HighProximity
Final forecastFinal forecast, made 10 min before the pass.
Closest approach29 Oct 202612:01 UTC
Relative speed7.24 km/sat the closest approach
Altitude583 kmlow Earth orbit
Last confirmed29 Oct11:51 UTC · final forecast

US R5-S9 and UK AAC-IO1 were predicted to reach a closest approach of 1.25 km at 2026-10-29 12:01 UTC, at a relative speed of 7.24 km/s. Final forecast, made 10 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
R5-S9Payload
NORAD 69901
CountryUS
Launched2026-07-07
COSPAR2026-156AJ
Maneuver capableUnknown
AAC-IO1Payload
NORAD 68498
CountryUK
Launched2026-03-30
COSPAR2026-067CL
Maneuver capableUnknown

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 583 KMISS 420Starlink 550

At 583 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

1 predicted pass under 10 km
Pair history · R5-S9 ⟷ AAC-IO1
2026-10-29 12:011.25 km Final forecast7.24 km/s583 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 Nothing is overwritten: a withdrawn forecast keeps its figure, with the newer check beside it, and the best estimate after the pass is a row of its own.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
29 Oct 09:51 UTC1.25 km Forecast29 Oct 12:01 UTC28 Oct 06:39 UTCRe-check
29 Oct 09:31 UTC1.79 km Forecast29 Oct 12:01 UTC28 Oct 06:39 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
1.77 km10-23 21:57 UTC
R5-S9CZ-6A DEB
2.84 km10-26 20:29 UTC
R5-S9HORYU 2
2.99 km10-26 23:37 UTC
YAOGAN 3AAC-IO1

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 →

Cite this encounter: Orbital Radar — “R5-S9 ⟷ AAC-IO1: 1.25 km predicted close approach”, https://orbitalradar.com/conjunction/68498-69901 (accessed 2026-10-29).