| Primary satellite | Secondary satellite |
| Name | M-CUBED/EXP-1 PRIME | COSMOS 2503 |
| Spacetrack catalog number | 37855 | 40420 |
| Radar cross section | small | large |
| Epoch of two-line elements (UTC) | 2021 Mar 05 21:11 | 2021 Mar 06 05:54 |
| Time of closest approach (UTC) | 2021 Jan 22 21:43:18.181 |
| Minimum distance | 2.315 km |
| Height difference | 1.365 km |
| Relative speed | 14.085 km/s |
| Angle between velocity vectors | 137° |
| Geographic position | 62.1°S, 60.3°W |
| Height | 589 km |
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