This missile originates from the Soviet R-17 missile and seems to be designed according to the Hwasŏng-6/Scud-C principles for maximum performance while maintaining the same engine and basically the same guidance system. At present, there is no reliable, open-source information on the origin and the history of this missile, including the connections to other Soviet-era programs.
The missile resembles a typical guided liquid rocket designed for maximum propellant load. It consists of one main engine, one propellant tank with a common bulkhead with an internal fuel line, a separate guidance compartment, and a conical warhead.
The basic construction material is stainless steel plus some air frame structural elements made of aluminum alloy. It does not differ from the Hwasŏng-5.
The propulsion system is a liquid rocket engine using the storable propellant combination of inhibited red fuming nitric acrid (IRFNA) and kerosene. Ignition is accomplished by a hypergolic (self-igniting) start fuel designated Tonka--the WW II German designator for this propellant--filled into the fuel line at the main fuel valve. The propellant feed system is a turbo pump driven by a bipropellant gas generator using the main propellants. The start and shut down valves are one shot devices, actuated by pyrotechnic charges. For improving the accuracy the engine is equipped with mechanical controls for correct thrust level and mixture ratio. Tank pressurization is performed by air stored in a toroidal high-pressure bottle at the bottom of the missile's warhead section and heated by the turbine exhaust gases.
The guidance system basically resembles that of the A4/V2 arrangement with body-mounted free gyros, however, with the modification of an additional gyro for accuracy improvement. Prior to launch, the missile is orientated such that the trajectory plane hits the target and the guidance systems keeps the missile in this plane. Two of the three body mounted gyros are used for attitude and the third one lateral acceleration control. A pendulum integration gyro assembly serves for speed measurement. The fins are fixed and thrust vector control is accomplished by four jet vanes.
Due to tank lengthening to achieve increases in propellant loads relative to the Hwasŏng-5, the guidance compartment on the "Scud-D" is shifted towards the missile's warhead with the cylindrical section comprising simply a connecting ring.
Unlike the Hwasŏng-5 and Hwasŏng-6, the propellant tank arrangement is changed such that the oxidizer tank is placed on top of the fuel tank, probably due to center of gravity reasons.
No open-source, reliable data on the transporter erector launcher (TEL) type are available; however the use of the Hwasŏng-5 and Hwasŏng-6 Soviet MAZ 543 TEL is very likely.
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Updated May 2003 |
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