| Primary satellite | Secondary satellite |
| Name | Envisat | COSMOS 2251 DEB |
| Spacetrack catalog number | 27386 | 34818 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Apr 16 14:23 | 2021 Apr 16 10:51 |
| Time of closest approach (UTC) | 2021 Mar 07 11:14:57.584 |
| Minimum distance | 6.665 km |
| Height difference | 1.261 km |
| Relative speed | 14.904 km/s |
| Angle between velocity vectors | 172° |
| Geographic position | 17.5°S, 91.0°W |
| Height | 771 km |
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