| Primary satellite | Secondary satellite |
| Name | Cosmos 1125 Rocket | COSMOS 2251 DEB |
| Spacetrack catalog number | 11511 | 47053 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 20 12:05 | 2021 Jan 18 22:33 |
| Time of closest approach (UTC) | 2020 Dec 10 00:13:03.142 |
| Minimum distance | 25.277 km |
| Height difference | 2.541 km |
| Relative speed | 14.506 km/s |
| Angle between velocity vectors | 148° |
| Geographic position | 1.7°S, 54.5°E |
| Height | 767 km |
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