_ an Eclair 35 mm motion picture camera. The RB-36 was positioned sixty miles from Ground Zero for the purpose of photographing cloud phenomenology. For approximately ten minutes after the shot it orbited at 35,000 to 40,000 feet altitude. The C-54's, with a bank of cameras located in the cargo entrance, took fireball and cloud rise and growth photography from altitudes of 10,000, 12,000 and 14,000 feet and a distance of about eighty miles. The C—54's took pictures from Time Zero wntil the cloud lost its identity. These aircraft were on loan from MATS and were modi- fied at Norton AFB, California, to accept camera racks and associated equipment from Air Force Lookout Mountain Photographic Laboratory. The B-50 took radar scope pictures from distances of fifteen to thirty miles ; at 30,000 feet for study of indirect bomb damage assessment and base surge characteristics. This information was then added to that gained from ground photography performed by Lookout Mountain Laboratory. On selected occasions, the SAC IBDA B-50's photographed thecrater after completing their IBDA rus. Approximately forty aircraft were airborne in the shot area for each detonation. Since each nuclear burst took place before daylight, careful aircraft control was necessary. Therefore two radar control centers were operated, one at Eniwetok and the other aboard the USS ESTES at Bikin4. Under continuous radar control and surveillance, each air- craft was brought from Eniwetok to Bikini, positioned for its role in the shot, and then returned to Eniwetok. Throughout the mission all aircraft -» were in constant communication with the control centers and received their instructions through this system. AFWL/HO 57