HomeManeuver TrackerClose ApproachesCOSMOS 252 DEB ⟷ TRANSIT 5B-2 DEB
high · CROSS-BORDER
6.80 kmmiss distance
Closest approach (TCA)
2026-09-09 12:30 UTC
Relative speed
14.01 km/s
Altitude
Current separation
Share 𝕏 R

On 2026-09-09 12:30 UTC, RU COSMOS 252 DEB and US TRANSIT 5B-2 DEB reached a closest approach (TCA) of 6.80 km, with a relative velocity of 14.01 km/s. 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 values update as new element sets are published. See the Satellite Maneuver Tracker for the live picture and space situational awareness for context.

Why it mattersNeither object can maneuver: the miss distance will evolve only with natural orbital perturbations, so screening continues until the pass is over.

The Two Objects

Dossiers from the satellite directory
NORAD 18490
CountryCIS
Launched1968-11-01
COSPAR1968-097EN
Maneuver capableNo
Uncontrolled debris fragment tracked by the public catalogue. About space debris →
NORAD 25156
CountryUS
Launched1963-12-05
COSPAR1963-049N
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 · 1054 KMISS 420Starlink 550

At 1054 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 recorded pass under 10 km
Pair history · COSMOS 252 DEB ⟷ TRANSIT 5B-2 DEB
Now6.80 km14.01 km/s1,054 kmThis page

Repeat encounters are common for objects in near-intersecting orbital planes; each pass is re-screened as fresh element sets arrive.

These Objects Elsewhere

Other screened approaches · 7 days
5.32 km09-13 09:25 UTC
COSMOS 252 DEBCZ-4 DEB
7.47 km09-13 17:46 UTC
COSMOS 839 DEBCOSMOS 252 DEB
9.07 km09-15 01:47 UTC
COSMOS 252 DEBSL-16 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 →

Cite this encounter: Orbital Radar — “COSMOS 252 DEB ⟷ TRANSIT 5B-2 DEB: 6.80 km close approach”, https://orbitalradar.com/conjunction/18490-25156 (accessed 2026-09-15).