US Air Force's Flying Nuclear Sniffer: Boeing WC-135 Constant Phoenix

The Boeing WC-135 Constant Phoenix is an unusual aircraft that plays a critical role in nuclear detection and arms-control monitoring. Its mission is to collect radioactive particles and gases from the atmosphere, which can reveal what happened after a nuclear event.

Unlike satellites and ground-based sensors, this aircraft can directly collect atmospheric material for laboratory analysis. This gives it a unique value in detecting and characterizing nuclear events.

The WC-135R is the latest generation of this specialized aircraft, with modernized engines and avionics replacing older equipment. The Air Force replaced its aging fleet with three new WC-135Rs between July 2022 and December 2023.

This aircraft operates as part of a larger nuclear detection network, working alongside other technologies to detect and analyze nuclear events. Its role is not just about detecting an event, but also providing physical evidence that can be studied.