Upshot-Knothole Dixie was the fourth test-firing of Operation Upshot–Knothole, an atomic weapons test series conducted in 1953 by the United States at the Nevada Test Site.
Upshot-Knothole Dixie was an 11-kiloton airdrop shot which detonated at 6,000 feet altitude, the highest air burst detonation conducted to that date.
See also 1953 in the environment Nuclear Test Ban Treaty Linus Pauling
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