| Primary satellite | Secondary satellite |
| Name | STARS | COSMOS 2251 DEB |
| Spacetrack catalog number | 33498 | 35587 |
| Radar cross section | medium | small |
| Epoch of two-line elements (UTC) | 2021 Mar 03 09:46 | 2021 Mar 02 17:11 |
| Time of closest approach (UTC) | 2021 Jan 20 05:24:38.610 |
| Minimum distance | 28.908 km |
| Height difference | -4.036 km |
| Relative speed | 4.005 km/s |
| Angle between velocity vectors | 31° |
| Geographic position | 37.5°N, 117.7°W |
| Height | 631 km |
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