Kh-55

Kh-55/65/101/102/555 AS-15 Kent
Kh-55 in the Ukrainian Air Force Museum
Type	Air-launched strategic cruise missile
Place of origin	Soviet Union
Service history
In service	1983-present
Used by	Russia, China, Iran
Wars	Syrian Civil War
Production history
Designed	1971-1981
Manufacturer	Raduga OKB
Unit cost	unknown
Produced	1981
Specifications
Weight	1,650 kg (3,640 lb) (Kh-65SE) 2,400 kg (5,300 lb) (Kh-101)
Length	604 cm (19 ft 10 in) (Kh-65SE) 745 cm (24 ft 5 in) (Kh-101)
Diameter	51.4 cm (20.2 in) (Kh-55-Kh-55SM)
Warhead	Thermonuclear weapon or Conventional warhead
Blast yield	Nuclear 200kt (Kh-55-Kh-55SM)
Engine	turbofan (Kh-55-Kh-55SM) 400 kgf (Kh-55-Kh-55SM)
Wingspan	310 cm (122.0 in) (Kh-55-Kh-55SM)
Propellant	jet fuel
Operational range	2,500 km (1,300 nmi) (Kh-55) 3,000 km (1,600 nmi) (Kh-55SM) 600 km (320 nmi)(Kh-65SE) 300 km, later 600 km(Kh-SD)
Flight altitude	under 110 m/300 ft
Speed	Mach 0.75 (KH-SD) Mach 0.6-0.78 (Kh-101)
Guidance system	inertial guidance with Doppler radar/terrain map updates; Kh-SD had a TC/IIR terminal guidance system, and an alternative active radar homing seeker was proposed
Launch platform	Tu-95MS, Tu-160, Su-34

The Kh-55 (Russian: Х-55, also known as RKV-500; NATO reporting name: AS-15 'Kent') is a Soviet/Russian subsonic air-launched cruise missile, designed by MKB Raduga. It has a range of up to 2,500 km (1,350 nmi) and can carry nuclear warheads. Kh-55 is launched exclusively from bomber aircraft and has spawned a number of conventionally armed variants mainly for tactical use, such as the Kh-65SE and Kh-SD, but only the Kh-101 and Kh-555 appear to have made it into service. Contrary to popular belief, the Kh-55 was not the basis of the submarine- and ground-launched S-10 Granat or RK-55 Relief (SS-N-21 'Sampson' and SSC-X-4 'Slingshot') designed by NPO Novator. The RK-55 is very similar to the air-launched Kh-55 (AS-15 'Kent') but the Kh-55 has a drop-down turbofan engine and was designed by MKB Raduga. Both have formed the basis of post-Cold-War missiles, in particular the Sizzler which has a supersonic approach phase.

A Kh-55 production unit was delivered to Shanghai in 1995 and appears to have been used to produce a similar weapon for China.

In the late 1960s, the "Ekho" study conducted by the GosNIIAS institute concluded that it would be more effective to deploy lots of small, subsonic cruise missiles than the much more expensive supersonic missiles then in favour. Work started at the Raduga bureau on an air-launched cruise missile in 1971, with a first test flight in 1976. The appearance of the US Air Force's AGM-86 ALCM in that year gave further impetus to the programme, with the Soviet Air Force issuing a formal requirement for a new air-launched cruise missile in December 1976. The longer-range Kh-55SM was developed a few years after the original went into service. In the late 1980s work began on a replacement missile with either conventional (Kh-101) or nuclear (Kh-102) warheads and greater stealth. It was designed by Igor Seleznyev of Raduga. The importance of advanced missiles as "force multipliers" increased as Russia's fleet of available cruise-missile bombers declined in the early 1990s. The cancellation of the ambitious Kh-90 ramjet missile due to INF treaty in 1987 led to a renewed emphasis on improving the Kh-55, in particular to achieve the <20 m accuracy required to hit infrastructure targets with conventional - as opposed to nuclear - warheads. First flight of the Kh-101 was in 1998, and evaluation trials started in 2000.