Cryogenics give pilots breath of fresh air
A cart valve frosts over while 31st Logistics Readiness Squadron fuels facility Airmen refill it with liquid nitrogen, Aug. 10, 2016, at Aviano Air Base, Italy. Cryogenics Airmen fill an average of 1,200 gallons of liquid oxygen and 1,200 gallons of liquid nitrogen monthly. (U.S. Air Force photo by Senior Airman Areca T. Bell/Released)