Russia launched its small rocket, the Angara-1.2 from the Plesetsk launch site at 1955 GMT on 29 April. A military satellite codenamed Cosmos 2555 (Kosmos-2555) was launched into a very low Sun-synchronous 294 x 279 km orbit at 96.5 degrees inclination. The exact nature of this satellite is unknown but it is known to be military. Astrophysicist and orbits expert Jonathan McDowell notes its orbital and orbital plane similarity to the Cosmos 2551, which is thought to be a Razbeg small optical reconnaissance satellite aka MKA-R using derivative of the EMKA (Experimental Small Space Apparatus) bus design.
Update on 16 May 2022: The Cosmos 2555 satellite has not moved from its orbit and is now thought to have failed in orbit after launch (or that it was always just a dummy satellite).