Operation CROSSROADS During Hiroshima and Nagasaki, no attempt was made to collect samples of any type, These were the only nuclear detonations made by the United States which did not have spme samples taken. They were followed in July 1946, by Operation CROSSROADS, the first of many elaborately planned and conducted tests on the new energy. During CROSSROADS, the debris ‘from an atomic cloudwas sampled by aircraft for the first time > The greater part of the Operation CROSSROADS program involved the United States Navy. From target arrangement to support units, the operation was almost entirely- Navy with naval personnel filling 90 per cent of the posts. On 29 December 1915, the Joint Chiefs of Staff appointed Vice Admiral William H. P. Blandy, an ordnance specialist, to command Task Force One, the organization which would conduct the tests. President Truman, on 10 Jamary 1946, approved the appointment and, the next day, the Task Force was activated. 2 Air operations for CROSSROADS was commanded by Major General W, E. Kepner, Army Air Forces, General Kepner had wide experience in aviation commands and was familiar with both Army and Navy air activities, t! Admiral Blandy organized a mumber of task groups for specific functions, a practice which was contimed through nuclear test programs including the overseds- tests conducted ten years later in 1956, Under the Task Force, the Army Air Forces established Task Group 1.5, commanded by Brigadier General R. M, Ramey. General Ramey's Task Group was responsible for all Army Air Force activities during Operation 3 APWLHC SWEH-2-003) 4 aN{0%