| Primary satellite | Secondary satellite |
| Name | Cosmos 1125 Rocket | COSMOS 2251 DEB |
| Spacetrack catalog number | 11511 | 35453 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 16 12:51 | 2021 Jan 06 20:52 |
| Time of closest approach (UTC) | 2020 Nov 28 03:44:15.035 |
| Minimum distance | 93.008 km |
| Height difference | -0.501 km |
| Relative speed | 2.034 km/s |
| Angle between velocity vectors | 16° |
| Geographic position | 74.0°S, 61.5°W |
| Height | 807 km |
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