The Kh-555 is a Russian long-range, subsonic cruise missile with a conventional or nuclear warhead, and its history can be traced back to the development of the Kh-55 in the late 1970s and early 1980s. The Kh-55, also known as the AS-15 'Kent', was designed by the Soviet Union's Raduga Design Bureau as an air-launched weapon for strategic bombers like the Tupolev Tu-95MS and Tu-160. The missile entered service in the early 2000s and has since become an important component of Russia's airborne strategic force.