| Primary satellite | Secondary satellite |
| Name | Cosmos 1125 Rocket | COSMOS 2251 DEB |
| Spacetrack catalog number | 11511 | 34972 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 15 20:08 | 2021 Jan 15 12:47 |
| Time of closest approach (UTC) | 2020 Nov 28 09:46:16.589 |
| Minimum distance | 46.693 km |
| Height difference | -3.131 km |
| Relative speed | 13.538 km/s |
| Angle between velocity vectors | 130° |
| Geographic position | 49.2°N, 105.1°E |
| Height | 767 km |
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