| Primary satellite | Secondary satellite |
| Name | Cosmos 1666 Rocket | YAOGAN 29 DEB |
| Spacetrack catalog number | 15890 | 42673 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2025 May 11 19:48 | 2025 May 11 21:48 |
| Time of closest approach (UTC) | 2024 Jun 25 19:11:08.627 |
| Minimum distance | 148.290 km |
| Height difference | -19.572 km |
| Relative speed | 15.080 km/s |
| Angle between velocity vectors | 177° |
| Geographic position | 59.8°S, 163.7°E |
| Height | 640 km |
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