| Primary satellite | Secondary satellite |
| Name | Envisat | COSMOS 2251 DEB |
| Spacetrack catalog number | 27386 | 34297 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Apr 16 14:23 | 2021 Apr 16 10:27 |
| Time of closest approach (UTC) | 2021 Mar 04 16:17:49.137 |
| Minimum distance | 6.867 km |
| Height difference | -2.686 km |
| Relative speed | 14.916 km/s |
| Angle between velocity vectors | 172° |
| Geographic position | 15.7°N, 161.7°W |
| Height | 767 km |
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