Tech. Sgt. Alexander Sasser, 379th Expeditionary Logistics Readiness Squadron fuels cryogenics NCO in charge, levels out the gauge to ensure the right amount of pressure is in a 50-gallon liquid oxygen tank during an inspection Aug. 5, 2016, at Al Udeid Air Base, Qatar. The cryogenics team here produces liquid oxygen, which is primarily used as aviator breathing oxygen, and liquid nitrogen, which is used for tire pressure and medical purposes. (U.S. Air Force photo/Senior Airman Janelle Patiño/Released)