Freezing Air: Airmen prepare liquid oxygen for sampling
U.S. Air Force Tech. Sgt. Jason Powers, 20th Logistics Readiness Squadron NCO in charge of fuels fixed facilities, releases a valve on a liquid oxygen tank at Shaw Air Force Base, S.C., June 26, 2014. Powers, one of two specially trained cryogenic experts here, released the liquid oxygen into a smaller tank, which is then inverted, forming a gas, and it is then tested for purity. (U.S. Air Force photo by Airman 1st Class Jensen Stidham/Released)