| Primary satellite | Secondary satellite |
| Name | Cosmos 858 Rocket | IRIDIUM 33 DEB |
| Spacetrack catalog number | 9444 | 46972 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2021 Jan 24 10:28 | 2021 Jan 17 10:23 |
| Time of closest approach (UTC) | 2020 Dec 01 22:07:51.545 |
| Minimum distance | 16.820 km |
| Height difference | -0.064 km |
| Relative speed | 4.155 km/s |
| Angle between velocity vectors | 32° |
| Geographic position | 65.4°S, 50.7°E |
| Height | 782 km |
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