| Primary satellite | Secondary satellite |
| Name | Cosmos 1666 Rocket | FENGYUN 1C DEB |
| Spacetrack catalog number | 15890 | 31165 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2024 Dec 22 16:44 | 2024 Dec 22 00:37 |
| Time of closest approach (UTC) | 2024 Dec 28 06:43:42.940 |
| Minimum distance | 3.375 km |
| Height difference | -3.115 km |
| Relative speed | 15.087 km/s |
| Angle between velocity vectors | 178° |
| Geographic position | 48.9°S, 2.0°W |
| Height | 646 km |
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