| Primary satellite | Secondary satellite |
| Name | Vanguard 2 | Sirio 1 Rocket |
| Spacetrack catalog number | 11 | 10295 |
| Radar cross section | medium | large |
| Epoch of two-line elements (UTC) | 2025 Dec 08 16:26 | 2025 Dec 08 07:25 |
| Time of closest approach (UTC) | 2024 Nov 10 09:17:38.332 |
| Minimum distance | 158.898 km |
| Height difference | -32.691 km |
| Relative speed | 1.948 km/s |
| Angle between velocity vectors | 15° |
| Geographic position | 24.5°N, 11.9°W |
| Height | 1240 km |
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