4.9.1 Background and Objectives of Operation UPSHOT-KNOTHOLE. UPSHOT-KNOTHOLE went a step further than the previous CONUS series, TUMBLER-SNAPPER, which had explored the use of nuclear weapons for tactical purposes. Designed to address both the tactical and strategic considerations of the U.S. defense policy, UPSHOT-KNOTHOLE was designed to accomplish the following (11: 33): e Establish military doctrine for the tactical use of nuclear weapons e Improve the nuclear weapons used for strategic bomber delivery and those used for tactical battlefield situations. Like the earlier BUSTER-JANGLE and TUMBLER-SNAPPER series, UPSHOTKNOTHOLE was initially envisioned as two separate weapons testing programs: Operation UPSHOT and Operation KNOTHOLE. Plans began in late 1951 for a large military effects test, later called Operation KNOTHOLE, to be conducted during the spring of 1953 at the NTS. The objective was to obtain general weapons effects information to supplement the data obtained from Operation GREENHOUSE, conducted at the Pacific during spring 1951 (11: 32). Meanwhile, the AEC was planning Operation UPSHOT, with the earliest test date set for spring 1953. The DOD consequently accelerated its planning for Operation KNOTHOLE so that arrangements for the AEC and DOD tests could be coordinated. In June 1952, the DOD and AEC agreed to conduct the spring 1953 tests as a combined operation, designated UPSHOT-KNOTHOLE (11: 32). 4.9.2 UPSHOT-KNOTHOLE Test Operations. An estimated 18,000 DOD personnel participated at UPSHOT-KNOTHOLE in observer programs, tactical maneuvers, scientific studies, and support activities. The largest DOD participation was in Exercise Desert Rock V, which involved members of all four armed services. Exercise Desert Rock V included troop orientation and training, a volunteer officer observer program, tactical troop maneuvers, operational helicopter tests, and damage effects evaluation. The troop orientation and training included briefings before the detonation on nuclear weapons characteristics and effects and on personal protection; figure 12 is a photograph of one such briefing (E). Troop orientation and training also involved observation of a nuclear detonation, as 100