| Primary satellite | Secondary satellite |
| Name | Cosmos 773 Rocket | COSMOS 2251 DEB |
| Spacetrack catalog number | 8344 | 34729 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Apr 12 08:20 | 2021 Apr 12 12:24 |
| Time of closest approach (UTC) | 2021 Mar 08 07:54:15.268 |
| Minimum distance | 31.435 km |
| Height difference | -1.705 km |
| Relative speed | 6.868 km/s |
| Angle between velocity vectors | 55° |
| Geographic position | 72.1°N, 83.9°W |
| Height | 759 km |
|