Kh-55, Russian Cruise Missile

The Kh-55 is a Russian air-launched cruise missile, designed by MKB Raduga. It has a range of up to 3,000 km (1,620 nmi) and can carry conventional or 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 RK-55 Granat (SS-N-21 'Sampson' and SSC-X-4 'Slingshot').

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

KH-55 Design

It is powered by a single R95-300 turbofan engine, with pop-out wings for cruising efficiency. It can be launched from both high and low altitudes, and flies at subsonic speeds at low levels (under 110 m/300 ft altitude). After launch, the missile's folded wings, tail surfaces and engine deploy. It is guided through a combination of an inertial guidance system plus a terrain contour-matching guidance system which uses radar and images stored in the memory of an onboard computer to find its target. This allows the missile to guide itself to the target with a high degree of accuracy, with a reported CEP of 15 meters.

The original Kh-55 had a drop-down engine; the Kh-65SE had a fixed external turbojet engine, whilst the Kh-SD had its engine inside the body of the missile.

Kh-55/65/101/102/555 (NATO reporting name: AS-15 'Kent')
Type	Air-launched strategic cruise missile
Place of origin	Soviet Union
Service history
In service	1984-current
Used by	Russia, China, Iran
Production history
Manufacturer	Raduga OKB / M. I. Kalinin Machine Building Plant
Specifications
Weight	1,650 kg (3,640 lb) (Kh-65SE) 2,200–2,400 kg (4,900–5,300 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-55SM)
Warhead	Nuclear
Warhead weight	200kT (Kh-55SM)
Wingspan	310 cm (122.0 in) (Kh-55SM)
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)
Speed	Mach 0.75 (KH-SD) Mach 0.6-0.78 (Kh-101)
Guidance system	inertial with Doppler radar/terrain map updates; Kh-SD had a TC/IIR terminal guidance system, and an alternative active radar seeker was proposed
Accuracy	6–9 m (20–30 ft) (Kh-101)
Launch platform	Tu-95MS, Tu-142M, Tu-160, Su-34

KH-55 Variants

• Kh-55 (NATO 'Kent-A', RKV-500A, Izdeliye 120) - original model with 2,500 km range.
• Kh-55-OK - development name of Kh-55SM
• Kh-55SM (NATO 'Kent-B', RKV-500B, Izdeliye 121) - with TERCOM (Terrain Contour Matching) navigation and extra fuel tanks to extend range to 3000 km.
• Kh-101/102 (Izdeliye 111) - developed as a more stealthy replacement for the Kh-55SM in the late 1980s, the Kh-101 has a conventional warhead and the Kh-102 is nuclear. A propfan version with 5000 km range was cancelled in 2000. Accuracy is reportedly 6–9 m.
• Kh-65SE - tactical version announced in 1992 with 410 kg conventional warhead and restricted to the 600 km range limit of the INF treaty.
• Kh-SD (средней дальности Srednei Dalnosti - 'Medium Range') - 300 km range conventional version announced in 1995, possibly for export. Shared components with the Kh-101, range reportedly increased to 600 km with a high-altitude approach, but the Kh-SD was apparently shelved in 2001. An alternative active radar seeker was proposed for anti-shipping use.
• Kh-555 (NATO 'Kent-C', Kh-55SE, Kh-55Sh) - conventionally-armed version with an improved guidance system and warhead developed in response to the lessons of the NATO air offensive against Yugoslavia in 1999. It became operational in 2000.

It was believed originally that the RK-55 (SSC-X-4 'Slingshot' and SS-N-21 'Sampson') were land- and submarine-launched derivatives of the Kh-55, but it is now known that the Kh-55 is different from the other two as its motor drops down below the missile during flight.