| Etalon-1 | |
| Mission Type: | Geodesy |
| Cospar Id: | 1989-001C |
| Satcat: | 19751 |
| Launch Date: | UTC[1] |
| Launch Site: | Baikonur Cosmodrome, Kazakhstan |
| Orbit Epoch: | 25 July 2018, 18:51:56 UTC |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Medium Earth |
| Orbit Inclination: | 64.1497 degrees |
| Orbit Eccentricity: | 0.0021819 |
| Orbit Period: | 675.56 minutes |
| Etalon-2 | |
| Mission Type: | Geodesy |
| Cospar Id: | 1989-039C |
| Satcat: | 20026 |
| Launch Date: | UTC[2] |
| Launch Site: | Baikonur Cosmodrome, Kazakhstan |
| Orbit Epoch: | 25 July 2018, 18:59:47 UTC |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Medium Earth |
| Orbit Inclination: | 65.2335 degrees |
| Orbit Eccentricity: | 0.0017121 |
| Orbit Period: | 675.41 minutes |
Etalon-1 and Etalon-2 are geodetic satellites. They are designed to determine, with high accuracy, terrestrial reference frame and Earth rotation parameters, to improve the gravity field, and to improve the gravitational constant. Each satellite is a high-density passive laser reflector in a very stable medium Earth orbit (MEO).[3]