North Korean Long-range Missile Debris Survey January 18, 2013 Ministry of Defense (English translation by D. Wright, revised 1/27/13)
General Period: December 14, 2012 January 9, 2013 Venue: Agency for Defense Development (Daejeon) Participants (52): From Intelligence HQ and agencies, Agency for Defense Development, KARI, and other relevant agencies Debris studied: first stage engine, fuel tanks and 10 items Galaxy-3 structure and principles Satellite compartment Intermediate stage Stage 3 Stage 2 tank inlet Connecting parts Fuel dispenser Stage 1 Fuel tank Turbo pump to inject oxidizer Engine Turbo pump to inject fuel Diameter of stage 1: 2.4m Gross weight: 91 tons (estimated), including 48 tons of oxidize * Dimensions of stages 2, 3, and satellite compartment are estimated
Findings Engine System Main engine structure / principles Turbo pump assembly Fuel Compressed air Main engine combustion chamber flow regulator Compressed air Auxiliary engines Nozzle Fuel flow regulator 1. is supplied to the main engine combustion chamber 4 through the turbo pump assembly 1 and the oxidizer flow regulator 2, and part of the oxidizer is supplied to the auxiliary engine combustion chamber 3. 2. Fuel is supplied through the turbo pump assembly 1 and the fuel flow regulator 5 to the main engine combustion chamber 4 and to the auxiliary engine combustion chamber 3. 3. Compressed air is used to pressurize the oxidizer and fuel tanks the oxidizer to give a smooth feed of fuel and oxidizer to each engine.
Turbo pump assembly: sends fuel and oxidizer to the engine with constant pressure. Fuel turbo pump turbo pump disassembled Turbo pump drive shaft cut - Regenerative cooling of the main engine is used to prevent overheating. Combustion chamber Nozzle Combustion chamber partial cut Engine combustion chamber cut Engine Engine nozzle partial cut Engine nozzle cut Auxiliary engines Bottom of stage 1?? Four auxiliary engines are located between the four main engines of the first stage. They each produce 3 tons of thrust and can rotate ± 36 to control the direction of the rocket.
Fuel Tank Structure General specifications Top part Bottom part Engine compartment connecting ring 1 Fuel inlet 3 Port to check fuel level 2 3 : part of missile name 4 Fuel outlet Fuel is kerosene with some additional hydrocarbon compounds added. Kerosene is a type of general-purpose fuel (such as in aircraft). The fuel tank is made of the magnesium alloy (AlMg6), which consists of 94% aluminum and 6% magnesium. The size of the fuel tank is 2/3 the size of the oxidizer tank.
Tank Structure 1 inlet 2 Support (2 places) 3 Name (2 places) 4 outlet 5 Exhaust port 1 inlet 2 Supporting part: Fuselage skeletal structures 3 Galaxy : missile name 4 outlet 5 Exhaust port: Allows air to vent with filling oxidizer, and allows checking oxidizer level * is nitric acid HNO3 (RFNA, Red fuming nitric acid) Assessment of oxidizer tank Exterior Interior Basic circular frames are in this region Weld lines All three types of supports are in this region Basic circular frames Circular frames I-beam frame tanks are made from aluminum-magnesium alloy (AlMg6) to prevent corrosion by nitric acid and to reduce the weight.
The oxidizer tank consists of several panels manually welded together. The welds are not uniform and were made using coarse techniques. Our assumption is that the I-beams and circular frames are installed inside the tank to prevent swirling and fluctuations of the liquid inside (the oxidizer has an estimated total weight of 48 tons when full) Exterior of oxidizer tank Left side Right side Braking motors 1 Camera 3 Exhaust tracks from braking motors 2 Cover for pressurized gas piping 4 electrical system conduit 1 The camera mounted on the stage 1 fuselage transmits the state of the engine to the ground in real-time. The video recording from the cameras was released through KCNA TV. 2 The cover of the gas piping is presumed to be used to protect the piping that takes pressurized gas to the oxidizer tank and to protect other electrical cables. 3 The braking motor is used during stage separation to slow the first stage and assure a safe distance from the second stage. Four braking motors were installed where the oxidizer and fuel tanks are connected. Exhaust tracks (soot) from the braking motors is visible on the missile body.
1-2 Separation Stage 2 Interstage Acceleration motor (6) Connection between tanks Stage 1 Braking motor (4) Fuel Engine Flight termination UHF antenna (2) The mechanism for stage separation is MDF (Mild Detonation Fuse), and consists of cutting devices at A and B, acceleration motors (6), and braking motors (4) * The accelerating and braking motors change the speed of the two stages to ensure a safe distance between them after separation. Two flight termination UHF antennas separated by 180 are used for precise control of the fuselage. Galaxy -3 Domestic and Foreign Parts North Korea used imported commercial products for most of the electronic devices and sensors, including temperature detection devices (DC-to-DC converters, temperature sensors), electric devices, pressure sensors, etc. The acceleration motors and some electronics were made in North Korea.
Comprehensive Assessments 1 Galaxy 3 used four 27-ton Nodong missile engines as expected, and uses four auxiliary engines each with 3 tons of thrust, for a total of 120-tons of thrust for the engine. The auxiliary engines enhance the thrust and control the direction of the rocket. 2 The oxidizer and fuel tanks had the expected structure. They are confirmed to be made of lightweight aluminum-magnesium alloys to prevent corrosion by HNO3 and reduce the weight. 3 Temperature detection devices (DC-to-DC converters, temperature sensors), pressure sensors, and some electronic devices and wires are commercial imported products, but we presume a majority of the other parts were made by North Korea. 4 Despite the limits on North Korea s procurement of advanced technology and parts due to sanctions by the international community, we assess that through experimentation and experience they enhanced the capability of their long-range missile.