A gaseous collection vessel known as “the sphere” is displayed during a WC-135 Constant Phoenix tour, Feb. 13, 2025 at Davis-Monthan Air Force Base, 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 Tech. Sgt. Rachel Maxwell)