| Primary satellite | Secondary satellite |
| Name | Transit 2A Rocket | COSMOS 2251 DEB |
| Spacetrack catalog number | 47 | 34387 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 17 20:42 | 2021 Jan 17 18:42 |
| Time of closest approach (UTC) | 2020 Dec 01 08:57:32.615 |
| Minimum distance | 17.960 km |
| Height difference | -2.748 km |
| Relative speed | 7.057 km/s |
| Angle between velocity vectors | 56° |
| Geographic position | 66.4°N, 56.7°W |
| Height | 778 km |
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