| Primary satellite | Secondary satellite |
| Name | Cosmos 1125 Rocket | COSMOS 2251 DEB |
| Spacetrack catalog number | 11511 | 37312 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 16 12:51 | 2021 Jan 16 17:27 |
| Time of closest approach (UTC) | 2020 Dec 03 04:41:55.172 |
| Minimum distance | 7.679 km |
| Height difference | -2.583 km |
| Relative speed | 13.726 km/s |
| Angle between velocity vectors | 133° |
| Geographic position | 46.5°N, 24.4°E |
| Height | 766 km |
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