U.S. Air Force Senior Airman Kyle Long, an aerospace and operational physiologist technician from Shaw Air Force Base, S.C., monitors Airmen sitting inside a high-altitude pressure chamber April 4 at Offutt Air Force Base, Neb. This is the last group of Airmen to take their training in this chamber at Offutt, which has been in place since 1957 and built out of World War II battleships. Slowly these types of altitude chambers are being phased out by newer technologies. (U.S. Air Force Photo by Josh Plueger/Released)