Close approach · predicted from public data
DMSP 5D-3 F16 (USA 172) and SL-16 R/B: 5.05 km apart
DMSP 5D-3 F16 (USA 172) (satellite) and SL-16 R/B (rocket body) are predicted to pass 5.05 km apart at 2026-10-14 10:26 UTC, about 832 km up, closing at 13.5 km/s.
After this encounter passes we check fresh tracking data for a week and report here what happened.
The two objects
| Object | NORAD | Type | Latest orbit data | Data age at approach |
|---|---|---|---|---|
| DMSP 5D-3 F16 (USA 172) | 28054 | satellite | 2026-10-08 08:02 UTC | 6.1 d screening: 7.2 d |
| SL-16 R/B | 23705 | rocket body | 2026-10-07 22:00 UTC | 6.5 d screening: 7.5 d |
What this is, and is not
This is a prediction built from public orbit data, which is accurate to roughly a kilometre and comes without uncertainty estimates. Operators get better data and formal warnings, and may already have moved. A prediction of a few hundred metres is common and rarely ends in a collision; it is the sheer number of them that makes orbit dangerous.
Orbits are calculated in your browser with SGP4, the same model used to produce the data, from CelesTrak GP data (CCSDS OMM). Screening by CelesTrak SOCRATES Plus. Earth imagery: NASA Blue Marble.