The United States's Toggle nuclear test series was a group of 28 nuclear tests conducted in 1972âÂÂ1973. These tests followed the Operation Grommet series and preceded the Operation Arbor series.
Diamond Sculls was a horizontal line-of-sight (HLOS) nuclear test. Its purpose was to test the radiation hardness of the LIM-49 Spartan anti-ballistic missile. It was the largest HLOS test conducted by the United States, consisting of a diameter test chamber and a line-of-sight pipe.