| Primary satellite | Secondary satellite |
| Name | Cosmos 1891 Rocket | FENGYUN 1C DEB |
| Spacetrack catalog number | 18403 | 29978 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 17 20:38 | 2021 Jan 17 21:17 |
| Time of closest approach (UTC) | 2020 Nov 30 03:22:19.678 |
| Minimum distance | 35.998 km |
| Height difference | -0.443 km |
| Relative speed | 13.496 km/s |
| Angle between velocity vectors | 132° |
| Geographic position | 80.9°S, 17.6°W |
| Height | 962 km |
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