Staff Sgt. Kajuan Green, 51st Logistics Readiness Squadron cryogenic storage supervisor conducts a quality control test on liquidized oxygen at Osan Air Base, Republic of Korea, Dec. 1, 2022. The quality control test ensures that pilots and air crews are provided with safe breathing oxygen when conducting missions at high altitudes. (U.S. Air Force photo by Staff Sgt. Dwane R. Young)