ROSE EVENT OPERATION HARDTACK 1. ROSE was detonated off Yvonne Island, Eniwetok Atoll, at O645M, 3 Jue 1958, 5,000 feet. The cloud rose to 17,000 feet; the base wes measured at The cloud moved in a westerly direction, but the top hoversd overhead. 2. The P2V aircraft arrived, and it was vectored from Dayid to Keith at 0720M, No readings were obtained on this run, so the sircraft was vectored up the island chain to Janet. over Yyonne at 0735M, A reading of 500 mr/hr was recorded Other readirgs were insignificant, thsn vectored across the lagoon in 10-degree increments. The P2V wes The only signifi- cant readings were recorded on a line vest of the roint of detonation. Re-entry hour was declared at 0745M axcept for the western reef area, which was held until 0845, 3. The helicopter survey wes initiated at 0&25M, readings were made on Janet: 50 mr/hr; Yvonne: ground zero at twenty-five feet: The only recorded 8 mr/hr; and near the 1200 mr/hr. 4, Fallout was estimated to have fallen well within the foresast fallout area, BEST COPY iVAILABLE TAB A (S59