| Primary satellite | Secondary satellite |
| Name | Cosmos 1766 | ESAIL |
| Spacetrack catalog number | 16881 | 46273 |
| Radar cross section | large | medium |
| Epoch of two-line elements (UTC) | 2021 Jan 27 15:33 | 2021 Jan 27 22:39 |
| Time of closest approach (UTC) | 2020 Nov 30 22:08:06.943 |
| Minimum distance | 3.955 km |
| Height difference | 3.944 km |
| Relative speed | 15.205 km/s |
| Angle between velocity vectors | 180° |
| Geographic position | 65.7°N, 158.1°W |
| Height | 533 km |
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