| Primary satellite | Secondary satellite |
| Name | Cosmos 1891 Rocket | FENGYUN 1C DEB |
| Spacetrack catalog number | 18403 | 31650 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 17 20:38 | 2021 Jan 16 22:26 |
| Time of closest approach (UTC) | 2020 Dec 02 18:10:19.465 |
| Minimum distance | 58.121 km |
| Height difference | -5.506 km |
| Relative speed | 14.596 km/s |
| Angle between velocity vectors | 168° |
| Geographic position | 80.7°S, 114.4°E |
| Height | 963 km |
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