| Primary satellite | Secondary satellite |
| Name | Cosmos 1656 | COSMOS 2251 DEB |
| Spacetrack catalog number | 15755 | 38006 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Mar 07 20:07 | 2021 Mar 08 11:05 |
| Time of closest approach (UTC) | 2021 Jan 21 04:30:40.861 |
| Minimum distance | 78.130 km |
| Height difference | 1.239 km |
| Relative speed | 3.728 km/s |
| Angle between velocity vectors | 29° |
| Geographic position | 71.2°S, 160.9°W |
| Height | 854 km |
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