detonation of the test shot, and continued until about dark when the cloud tracker aircraft retumned.>- BUSTER ABLE. Scheduled for the morning of 19 October 1951, the first shot was postponed, Test aircraft were in the air; however, the firing mechanism did not operate properly and the shot failed to detonate, The Atomic Energy Commission was successful with the device on the morning of 22 October 1951. The shot produced very little nuclear radiation and terrain survey and cloud tracker aircraft were cancelled, and one of the B-29samplers went home,” For ABLE Shot the B-29 samplers operated from Nellis Air Force Base, near Las Vegas, because Indian Springs had no night lighting facilities, The B-29 samplers’: carried on all flights a radiological officer and a trainee radiological officer, in addition to the regular crew, Each airplane collected data for both the AFOAT~1l organization and for the Atomic Energy Commission. Because of the low yield of the first shot, the B-29 which did not sample had a rather long mission, The first pass through the cloud resulted in no radiation being detected, Therefore, the sampler made eight more passes through the cloud at altitudes from 100 feet to 7,500 feet which finally resulted in adequate samples .>> It flew directly to Indian Springs Air Force Ease, landed, and taxied to the decontamination area where the crew left the aircraft through the nose wheel door and were carefully monitored for contamina- tion. Dr. Harold F, Plank, Los Alamos Scientific Laboratory radiation expert, with a crew of technicians from the laboratory, then went about removing the paper samples from the aircraft and preparing them for 2 APWL/HO SWEH-2-003, b sated s -