3.3. THE ADVISORY GROUP This group was composed of a numberof consultants in specialized fields. Its function was to advise the Commander, Task Group (CTG) 132.1 and the JTF 132 Deputy for Scientific Matters on the numerous and complex technical problemsinvolved in this operation. Representatives for health, safety, and weather were included in the group. The principal efforts of this group were directed toward the problems peculiar to the Mike device. The group acted as an inspection agency and represented LASL and AEC in certifying that, prior to its detonation, the Mike device was assembled and operating in the manner intended in ita design. It was the function of this group to make decisions and authorizations for any changes in the Mike device necessitated by field conditions. Fortunately the need for such changesdid not occur. The advisory group took an active part in the Mike assembly. Their advice and assistance was a major factor in the timely completion of the assembly. 3.4 PLANNING AND TRAINING 3.4.1 Device Planning One of the major purposes of Operation Greenhouse was to answer key questions relating to the possibility of developing thermonuclear explosions. The Greenhouse George and Item Shots were important steps in the investigation of basic problems in the developmentof a thermonucleardevice. t By August 1951 the Chairman of AEC had stated in a letter that a thermonuclear device would probably not be ready for testing prior to the winter of 1952-53. However, in late October 1951 he reported that progress in research and development activities had been such that a more realistic date for planning purposes appeared to be thefall of 1952, possibly 1 October. In addition to the thermonuclear device to be tested on Operation Ivy, the Director of LASL in- structed J-Division to plan for an airdrop of a high-yield (500 kt) fission weapon as a second Ivy event. In view of the October 1952 target date, the Panda staff, comprised of key personnel of LASL and certain contractors, was organized in October 1951 to consider the operational, design, fabrication, and planning problemarelated to the thermonuclear device to be tested dur- ing Operation Ivy. Initially,) ‘would be tested on Operation Ivy. Consideration was given to the possibility of testing this device in the “dry” form, but the lack of critical materials at this point indicated a need for the use of liquid deuterium. Variations in the design of the Mike device continued up to the time of final assembly. The King Shot weapon was particularly desirable to test in order to extend the knowledge of the effects of high-yield weapons and knowledge of certain factors involved in the design of high-efficiency weapons. The choice of a specific island for the detonation of a device with the predicted yield of Mike Shot (the thermonuclear device) presented many problems, both from construction and from experimental points of view. But by November, after consideration and discussion, the island group of Eniwetok Atoll from Elugelab clockwise to Bogon was decided on as the shotisland group, with Elugelab to be the shot island, thus permitting the use of the islands both east and west of the shot island for instrumentation. The sequence for the two detonations was initially decided to be King Shot, the high-yield fission weapon, followed by Mike Shot. However, further study in late February 1952 proved that it would be best to fire Mike Shot first. This would permit the greatest flexibility of oper- 19