RDS-4

RDS-4 (Russian: РДС-4, also known as Tatyana) was a Soviet nuclear bomb that was first tested at Semipalatinsk Test Site, on August 23, 1953. The device weighed approximately 1,200 kilograms (2,646 lb). The device was approximately one-third the size of the RDS-3. The bomb was dropped from an IL-28 aircraft at an altitude of 11 kilometres (7 mi) and exploded at 600 metres (1,969 ft), with a yield of 28 kt.
The Soviet Union's first mass-produced tactical nuclear weapon was based on the RDS-4 and remained in service until 1966.It used a composite core of 4.2 kilograms (9 lb) Pu-239 and 6.8 kilograms (15 lb) 90% enriched U-235 and had a nominal yield of 30 kilotons. RDS-4 "Tatyana" turned out to be very compact - its weight (1200 kg) and dimensions were four times less than that of RDS-1, which allowed the new bomb to be taken into service not only by long-range aviation (Tupolev Tu-4, Tupolev Tu-95, Tupolev Tu-16, Tupolev Tu-22, Myasishchev M-4, and Myasishchev 3M), but also front-line (Ilyushin Il-28, Yakovlev Yak-26, Yakovlev Yak-28, Mikoyan-Gurevich MiG-19, and Mikoyan-Gurevich MiG-21). A tactical weapon based on the RDS-4 was also used on September 14, 1954 during Snowball military...