Shot Dakota was a barge detonation of Operation Redwing, fired on 26 June 1956 in the Bikini Atoll lagoon. It was a prototype test of the TX-28C thermonuclear device — the development predecessor of the W-28 warhead, which became the most versatile and widely deployed thermonuclear weapon design ever adopted by the United States. Compact at 51 centimetres in diameter and 147 centimetres long, the W-28 entered service in 1958 and remained in the stockpile until 1991, fielded in five models across twenty variants. Dakota produced 1.1 megatons against a predicted yield of 800 kilotons, substantially exceeding expectations. Operation Redwing was the second American test series devoted primarily to proving thermonuclear weapon designs, conducted under a strict energy budget imposed in direct response to the unexpectedly high yield and fallout of Operation Castle — particularly the Castle Bravo event of 1954. The total yield limit for Redwing was set at approximately 20 megatons. The series used both Bikini and Enewetak atolls and proof-tested a broad range of second-generation thermonuclear designs, including the first three-stage thermonuclear systems ever tested and the first US airdrop of a thermonuclear weapon.