| Primary satellite | Secondary satellite |
| Name | Cosmos 1408 Rocket | COSMOS 2251 DEB |
| Spacetrack catalog number | 13553 | 40802 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Apr 14 06:24 | 2021 Apr 13 22:33 |
| Time of closest approach (UTC) | 2021 Mar 01 00:47:36.446 |
| Minimum distance | 27.172 km |
| Height difference | -3.983 km |
| Relative speed | 13.344 km/s |
| Angle between velocity vectors | 124° |
| Geographic position | 64.3°N, 101.8°W |
| Height | 643 km |
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