did the volunteer officer observer program. For the latter, trained staff officers calculated the effects of a nuclear detonation to determine a minimum safe distance for observing the blast; they later watched the detonation from the calculated position. Among the other activities, the operational helicopter tests performed by the Marine Corps were designed to investigate the capability of helicopters and their crews to withstand a nuclear burst and its effects (11: 1). 4.9.3 Dose Summary for Operation UPSHOT-KNOTHOLE. The maximum permissible dose for participants in the Joint Test Organization, which coordinated UPSHOT-KNOTHOLE, and AFSWC was 3.9 rem of gamma radiation for the series. The limits were higher for Desert Rock V participants, according to the requirements of their missions. Desert Rock V troops were restricted to a maximum of 6.0 rem of gamma radiation for the series, with no more than 3.0 rem of prompt radiation. The volunteer officer observers were limited to 10.0 rem of gamma radiation, with no more than 5.0 rem of prompt radiation per test, and a total of no more than 25.0 rem for the exercise (11: 11). Dosimetry information is available for the volunteer officer observers, who participated at Shots NANCY, BADGER, and SIMON. The exposures of seven of the eight SIMON observers exceeded the 10.0 rem shot limit, with a high of 17.5 rem. The one volunteer observer who witnessed all three shots had an exposure of 26.6 rem (11: 12). The calculated mean neutron doses for the volunteer observers have been reconstructed as 0.63 rem for Shot NANCY; 2.4 rem for Shot BADGER; and 28 rem for Shot SIMON (11: 12,15). 102