Airmen 1st Class Angelito Kamatoy and Nathanael Markley, 36th Logistics Readiness Squadron cryogenic production technicians, pull a daily sample from a tank April 8, 2015, at Andersen Air Force Base, Guam. Every 24 hours, a cryogenics airman pulls a sample to ensure liquid and gaseous nitrogen are produced are 99.5 percent pure. (U.S. Air Force photo by Senior Airman Katrina M. Brisbin/Released)