II Preliminary reports indicated that the samples were strong enough for laboratory experimentation, even though they were gathered long after detonation. Also, Colonel Cody reported: "The indicated exposure levels of the crews in these operations have been below those anticipated in the initial calculations." He advised that, if the Air Force planned to use manned samplers on future operations, more adequate instruments and equipment be developed. And, finally, ". . . it may be wise for the Air Force, if such operations are to be continued, that a test unit be formed to do this type of operation."” Operation GREENHOUSE Within a few months of the ending of Operation SANDSTONE, plans were under way for another nuclear test series in the Pacific in 1951. By mid-December 1918, the Los Alamos Scientific Laboratory established requirements for at least eight drone samplers which were to make about two penetrations, On 18 January 199, Air Materiel Command held a preliminary conference to consider drme requirements, ". . . since it was generally recognized that radiological sampling provided one of the most important methods of measuring weapon efficiency," Plans called for aircraft to penetrate the cloud at relatively slow speeds and it was decided B-l7 drone aircraft were to be used, However, a month later some officials considered changing the drone-type aircraft, but development necessary and the time were thought to be excessive, 3h awn In SYEH-2-003h 5° ANEW? -