| Primary satellite | Secondary satellite |
| Name | CSL-04 Rocket | COSMOS 2251 DEB |
| Spacetrack catalog number | 25732 | 37975 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Apr 16 18:04 | 2021 Apr 16 02:29 |
| Time of closest approach (UTC) | 2021 Mar 09 00:48:46.466 |
| Minimum distance | 17.364 km |
| Height difference | 4.624 km |
| Relative speed | 13.502 km/s |
| Angle between velocity vectors | 131° |
| Geographic position | 74.1°S, 71.9°E |
| Height | 855 km |
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