| Primary satellite | Secondary satellite |
| Name | COSMOS 2251 DEB | Cosmos 990 |
| Spacetrack catalog number | 35671 | 10676 |
| Radar cross section | small | large |
| Epoch of two-line elements (UTC) | 2024 Dec 21 12:45 | 2024 Dec 22 16:09 |
| Time of closest approach (UTC) | 2024 Dec 23 14:16:08.400 |
| Minimum distance | 4.770 km |
| Height difference | 4.765 km |
| Relative speed | 5.163 km/s |
| Angle between velocity vectors | 40° |
| Geographic position | 73.0°N, 172.7°W |
| Height | 776 km |
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