Editing Soviet atomic bomb project (section)

=== RDS-4 ===
[[RDS-4]] represented a branch of research on small tactical weapons. It used plutonium in a "levitated" core design. The first test was an air drop on August 23, 1953, yielding 28 kilotons. In 1954, the bomb was also used during [[Totskoye nuclear exercise|Snowball exercise]] at the [[Totskoye range]], dropped by [[Tupolev Tu-4|Tu-4 bomber]] on the simulated battlefield, in the presence of 40,000 infantry, tanks, and jet fighters. The RDS-4 comprised the warhead of the [[R-5 (rocket)|R-5M]], the first [[medium-range ballistic missile]] in the world, which was tested with a live warhead for the first and only time on February 5, 1956