| Primary satellite | Secondary satellite |
| Name | Cosmos 858 Rocket | FENGYUN 1C DEB |
| Spacetrack catalog number | 9444 | 31966 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 23 17:46 | 2021 Jan 24 05:45 |
| Time of closest approach (UTC) | 2020 Dec 02 07:56:08.687 |
| Minimum distance | 6.890 km |
| Height difference | -2.392 km |
| Relative speed | 14.789 km/s |
| Angle between velocity vectors | 166° |
| Geographic position | 59.2°S, 149.4°E |
| Height | 787 km |
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