| Primary satellite | Secondary satellite |
| Name | Envisat | COSMOS 2251 DEB |
| Spacetrack catalog number | 27386 | 34430 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Apr 10 11:41 | 2021 Apr 10 14:20 |
| Time of closest approach (UTC) | 2021 Mar 06 07:53:59.496 |
| Minimum distance | 4.540 km |
| Height difference | -4.295 km |
| Relative speed | 14.786 km/s |
| Angle between velocity vectors | 163° |
| Geographic position | 60.6°N, 127.3°E |
| Height | 776 km |
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