| Primary satellite | Secondary satellite |
| Name | Cosmos 1308 Rocket | Cosmos 1861 |
| Spacetrack catalog number | 12836 | 18129 |
| Radar cross section | large | large |
| Epoch of two-line elements (UTC) | 2025 Nov 13 02:16 | 2025 Nov 13 04:59 |
| Time of closest approach (UTC) | 2025 Oct 18 09:14:52.894 |
| Minimum distance | 3.672 km |
| Height difference | 2.402 km |
| Relative speed | 14.561 km/s |
| Angle between velocity vectors | 164° |
| Geographic position | 27.2°N, 20.4°W |
| Height | 994 km |
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