A Bulgarian air force Aero L-39 Albatros takes off during exercise Thracian Star 21 at Graf Ignatievo Air Base, Bulgaria, July 13, 2021. Thracian Star 21 is a multilateral training exercise with the Bulgarian air force, aimed to increase operational capacity, capability and interoperability with Bulgaria. (U.S. Air Force photo by Airman 1st Class Brooke Moeder)