The R-15 was a submarine launched ballistic missile (SLBM) design from the Soviet Union

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 during the Cold War

Cold War

The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

. It was not deployed.

The R-15 was a project to develop an SLBM complex D-3 with the capability to be launched directly from the submarine while submerged. The development was authorized for OKB-586 in Dnipropetrovsk, Ukraine, on 20 March 1958 and cancelled before testing in December 1958.