Program 2, Nuclear Radiation and Fallout; Projects 2.1, 2.2, 2.3, 2.5a, 2.5b, 2.6a, 2.6b @® Program 6, Systems Effects; Projects 6.1, 6.4, 6.5, 6.6 ATES E . KTweokt @e 6.2a, 6.2b, Program 7, Electromagnetics; Projects 7.1, 7.2, 7.4 Program 9, Cloud Photography; Project 9.1. The locations of the instrument stations for these projects are shown in Figure 78. Details of each project are given in Chapter 3. aircraft participation is given in Table 37. TG 7.4 Table 38 indicates the posi- tions of some of these aircraft at burst time. The Test At shot time (0620), a rain shower between the fleet and ground zero possibly extended to ground zero. about 55,000 feet (16.8 km). The debris cloud reached an altitude of The lowest portion of the stem (estimated at below 5,000 feet [1.5 km]) moved to the west at an average velocity of about 17.3 mi/hr (27.8 km/hr). (Contact was made with this portion of the cloud at H+5 by Wilson 2, about 59 nmi zero. The intensity was 0,015 R/hr.) (1.5 to 7.6 km) mi/hr 109 km to the west of ground The middle segments of the cloud initially moved north, then east-northeast at about 17.4 (28 km/hr). The top section of the cloud moved to the east-northeast at approximately 34 mi/hr CONTAMINATION. (55 km/hr) (Reference 16, Tab M). The Wilson 1 aircraft encountered radiation intensi- ties of 5 R/hr while collecting cloud samples. Wilson 2, flying at 10,000 feet (3.05 km), made no contact with the cloud while in the racetrack pattern between Bikini and Enewetak/Ujelang. Wilson 2 began a sector search at H+4 and located the cloud east of ground zero. foot This area was the forecast H+6 position of the 20,000- and 30,000(6.1- and 9.l-km) particle trajectories. R/hr was reported at H+5.5 about 100 nmi A maximum reading of 0.250 (185 km) east-northeast of Bikini. This layer of the cloud was probably responsible for the contamination subsequently noted at Rongerik and Rongelap atolls. 276