| Primary satellite | Secondary satellite |
| Name | Cosmos 921 Rocket | DNEPR OBJECT J |
| Spacetrack catalog number | 10096 | 39424 |
| Radar cross section | large | small |
| Epoch of two-line elements (UTC) | 2025 Nov 17 20:26 | 2025 Nov 17 18:53 |
| Time of closest approach (UTC) | 2025 Oct 14 05:27:58.639 |
| Minimum distance | 99.296 km |
| Height difference | 0.090 km |
| Relative speed | 13.997 km/s |
| Angle between velocity vectors | 136° |
| Geographic position | 75.7°S, 147.8°E |
| Height | 627 km |
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