U.S. Air Force Tech. Sgt. Richard Westra, special equipment operator assigned to the 21st Surveillance Squadron, Det. 1, left, shows Colombian Air Force Col. Alejandro Leguizamón, right, Air Forces Southern Foreign Liaison Officer, how atmospheric particles are collected during a WC-135 Constant Phoenix tour, Feb. 13, 2025 at Davis-Monthan AFB, Arizona. The WC-135, which traveled from Offutt AFB, Nebraska, plays a critical role in nuclear treaty monitoring by collecting airborne effluents and particulates. (U.S. Air Force Photo by Andrea Jenkins)