USAF
The U.S. Air Force has confirmed that a recent and unusual flight by its WC-135R Constant Phoenix ‘nuke sniffer’ jet, a converted KC-135 tanker, over the Atlantic Ocean off the coast of South America was the first time it has conducted an air-sampling sortie outside of the Continental United States. Constant Phoenix aircraft regularly conduct missions to gather data that can be used to help keep watch for unusual spikes in atmospheric radiation.