| Primary satellite | Secondary satellite |
| Name | Cosmos 858 Rocket | CZ-2C DEB |
| Spacetrack catalog number | 9444 | 39629 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 20 04:37 | 2021 Jan 19 22:37 |
| Time of closest approach (UTC) | 2020 Dec 01 04:05:24.544 |
| Minimum distance | 12.777 km |
| Height difference | 2.866 km |
| Relative speed | 14.947 km/s |
| Angle between velocity vectors | 172° |
| Geographic position | 0.4°S, 1.7°E |
| Height | 759 km |
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