Virginia Class Submarine, United States of America

The Virginia Class new attack submarine is an advanced stealth multimission nuclear-powered submarine for deep ocean anti-submarine warfare and littoral (shallow water) operations.
Although the Seawolf submarine was developed to provide an eventual replacement for the US Navy Los Angeles Class submarines in combating the Soviet forces, the prohibitive unit cost and changing strategic requirements led to the US Navy defining a smaller new-generation attack submarine.
Babcock & Wilcox (B&W) Nuclear Operations won a contract for the assembly of nuclear propulsion components for Virginia Class submarine in February 2013.

Virginia class submarines

The Electric Boat division of General Dynamics, Connecticut, is the lead design authority for the Virginia Class. General Dynamics Electric Boat has built the first of the class - Virginia (SSN 774), and Northrop Grumman Newport News the second - Texas (SSN 775).
The US Navy's total requirement is for 30 of the class. It placed a bulk-buy contract for the first five ships and, in January 2004, placed a multiyear contract for the following five. In December 2008, the navy signed a $14bn contract with General Dynamics and Northrop Grumman for eight more submarines.
Virginia was laid down in September 1999, launched in August 2003 and commissioned in October 2004. It underwent a three-year operational evaluation before operational deployment. Texas was launched in April 2005, delivered in June 2006 and commissioned in September 2006. The keel for Hawaii was laid in August 2004, it was launched in June 2006 and commissioned in May 2007.
North Carolina was launched in May 2007, delivered in December 2007 and commissioned in May 2008. New Hampshire was launched in February 2008 and commissioned in October 2008. The keel for New Mexico was laid in April 2008.
General Dynamics Electric Boat delivered the nuclear-powered attack submarine Mississippi (SSN-782) to the US Navy in May 2012.
The US Navy launched Minnesota (SSN 783) at Huntington Ingalls Industries (HII) in November 2012.
It was launched in December 2008 and commissioned in March 2010. Missouri (SSN 780) began construction in December 2004. Her keel was laid in September 2008, launched in November 2009 and commissioned in July 2010. The keel for California (SSN-781) was laid in May 2010.
Construction of SSN 786 began in March 2011 at General Dynamics Electric Boat. The US Navy then decided to build two Virginia class submarines a year. Accordingly, $1.2bn was released to General Dynamics in April 2011, to construct the 14th Virginia-class submarine SSN-787. Construction began in September 2011, the second in that year.
Construction of Colorado SSN 788 and Indiana SSN 789 began in March 2012 and September 2012 respectively.

Design of NSSN Virginia Class submarines

The engineering teams and design and build teams at Electric Boat in partnership with the Naval Sea Systems Command, NAVSEA, of the US Navy have used extensive CAD/CAE simulation systems to optimise the design of the submarine.
The hull size is length 377ft by beam 34ft and the displacement is 7,300t dived, which is smaller than the more expensive Seawolf attack submarine with displacement 9,137t dived.
The hull structure contains structurally integrated enclosures, which accommodate standard 19in and 24in width equipment for ease of installation, repair and upgrade of the submarine's systems.
The submarine is fitted with modular isolated deck structures, for example the submarine's command centre will be installed as one single unit resting on cushioned mounting points. The submarine's control suite is equipped with computer touch screens.
The submarine's steering and diving control is via a four-button, two-axis joystick.
The noise level of the Virginia is equal to that of the US Navy Seawolf, SSN 21, with a lower acoustic signature than the Russian Improved Akula Class and fourth-generation attack submarines. To achieve this low acoustic signature, the Virginia incorporates newly designed anechoic coatings, isolated deck structures and a new design of propulsor.
Goodrich is supplying high-frequency sail array acoustic windows and composite sonar domes.

Command system

The command and control systems module (CCSM) has been developed by a team led by Lockheed Martin Naval Electronics & Surveillance Systems - Undersea Systems (NE&SS-US) of Manassas, Virginia. It will integrate all of the vessel's systems - sensors, countermeasure technology, navigation and weapon control and will be based on open system architecture (OSA) with Q-70 colour common display consoles.
Weapon control is provided by Raytheon with a derivative of the CCS mk2 combat system, the AN/BYG-1 combat control system, which is also being fitted to the Australian Collins Class submarines.
The Virginia has two mast-mounted Raytheon submarine high data rate (sub HDR) multiband satellite communications systems that allow simultaneous communication at super high frequency (SHF) and extremely high frequency (EHF).

Weapon systems

The submarine is equipped with 12 vertical missile launch tubes and four 533mm torpedo tubes. The vertical launching system has the capacity to launch 16 Tomahawk submarine-launched cruise missiles (SLCM) in a single salvo. There is capacity for up to 26 mk48 ADCAP mod 6 heavyweight torpedoes and sub harpoon anti-ship missiles to be fired from the 21in torpedo tubes. Mk60 CAPTOR mines may also be fitted.
An integral lock-out / lock-in chamber is incorporated into the hull for special operations. The chamber can host a mini-submarine, such as Northrop Grumman's Oceanic and Naval Systems advanced SEAL delivery system (ASDS), to deliver special warfare forces such as navy sea air land (SEAL) teams or Marine reconnaissance units for counter-terrorism or localised conflict operations.

Countermeasures

 

Virginia is fitted with the AN/WLY-1 acoustic countermeasures system being developed by Northrop Grumman, which provides range and bearing data, along with the mast-mounted AN/BLQ-10 electronic support measures (ESM) system from Lockheed Martin Integrated Systems.
AN/BLQ-10 provides full spectrum radar processing, automatic threat warning and situation assessment.

Sensors

The Virginia Class sonar suite includes bow-mounted active and passive array, wide aperture passive array on flank, high-frequency active arrays on keel and fin, TB 16 towed array and the Lockheed Martin TB-29A thinline towed array, with the AN/BQQ-10(V4) sonar processing system. A Sperry Marine AN/BPS-16(V)4 navigation radar, operating at I-band, is fitted.
The submarines have two Kollmorgen AN/BVS-1 photonic masts, rather than optical periscopes. Sensors mounted on the non-hull-penetrating photonic mast include LLTV (low-light TV), thermal imager and laser rangefinder. The mast is the Universal Modular Mast developed by Kollmorgen and its Italian subsidiary, Calzoni.
The Boeing LMRS long-term mine reconnaissance system will be deployed on the Virginia Class. LMRS includes two 6m autonomous unmanned underwater vehicles, an 18m robotic recovery arm and support electronics.
Northrop Grumman Electronic Systems is supplying the lightweight, wide-aperture array (LWWAA) system based on fibre-optic arrays, instead of traditional ceramic hydrophone sensors.
LWWAA is a passive ASW sonar system which consists of three large array panels mounted on either side of the submarine's hull.
Lockheed Martin will provide acoustic rapid commercial off-the-shelf insertion (A-RCI) hardware for the sonar system upgrade. The $25.1m contract was awarded in August 2009. Deliveries are expected to be completed by December 2011.
In January 2011, a $84m contract was awarded to Lockheed Martin for submarine sonar upgrades.

Propulsion

The main propulsion units are the GE pressure water reactor S9G, designed to last as long the submarine, two turbine engines with one shaft and a United Defense pump jet propulser, providing 29.84MW. The speed is over 25kt dived.

Nuclear Submarine Yury Dolgoruky, Russian Federation

Yury Dolgoruky is a new-generation nuclear-powered ballistic missile submarine which was built by Sevmash shipyard for the Russian Navy. Constructed as the lead-submarine of the Project 955 Borei Class, Yury Dolgoruky is the first submarine launched by Russia after the Soviet era.
Yury Dolgoruky, deployed in the Pacific Fleet of the Russian Navy, is a key component of the country's nuclear-powered ballistic missile submarine fleet. The Borei Class submarines are intended to replace the Delta III, Delta IV and Typhoon classes of the Russian Navy.
In May 2012, the Russian Ministry of Defence placed a contract for the delivery of five new Project 955A Borei Class nuclear submarines. The Russian Navy plans to acquire ten new Borei Class submarines by 2020.

Construction and sea trials of Yury Dolgoruky

 

The keel for Yury Dolgoruky was laid in November 1996, but construction was largely delayed because of budget constraints. The submarine was finally launched in February 2008, while the on-board reactor was first activated in November 2008.
The initial sea trials began in June 2009 and were completed in July 2010. The subsequent sea trials were concluded in September 2010.
The submarine successfully launched the first RSM-56 Bulava submarine-launched ballistic missile (SLBM) in June 2011. Yury Dolgoruky completed its state trials in early 2012, and was officially commissioned into the Russian Navy in January 2013.
The other three Borei Class submarines currently being built are Alexander Nevsky, Vladimir Monomakh and Knyaz Vladimir.

Design features of the nuclear submarine

 

Yury Dolgoruky was designed by the Rubin Marine Equipment Design Bureau. The design incorporates a hydro-dynamically efficient hull. The outer hull is covered with anechoic coating to reduce its acoustic signature.
The submarine is equipped with pump-jet propulsion for carrying out quieter operations. Yury Dolgoruky is the first Russian submarine to use such a propulsion system.
The Borei Class vessel has a length of 170m, beam of 13.5m and a draught of ten metres. The surfaced and submerged displacements of the sub are 14,720t and 24,000t respectively. The submarine can hold a crew of 130 personnel.

Bulava submarine-launched ballistic missile

 

Yury Dolgoruky is armed with a RSM-56 Bulava SLBM, which was developed by the Moscow Institute of Thermal Technology.

Yury Dolgoruky can carry 16 Bulava SLBM, while the improved variants of Borei Class submarines can be armed with up to 20 missiles.
The three-stage missile uses solid fuel propellant for the first two stages and liquid fuel for the third stage. It can be classified as a quasi-ballistic missile because of its low flight trajectory. Bulava features advanced defence capabilities designed to penetrate enemy missile-defence systems. The missile can withstand a nuclear blast at a minimum range of 500m.
The missile has a length of 12.1m and diameter of 2.1m. It has an operational range of 8,000km and is capable of carrying up to ten independently guided, manoeuvrable warheads with an yield of 100-150kt each.

Anti-submarine warfare and pump-jet nuclear propulsion

 

Yury Dolgoruky is fitted with six 533mm torpedo tubes for launching six RPK-2 Viyuga (SS-N-15) missiles. Each SS-N-15 is capable of carrying a payload of a Type 40 torpedo or 90R nuclear depth charge. The missile can strike enemy submarines within a range of 45km, while travelling at a subsonic speed of Mach 0.9.
The submarine is propelled by pump-jet propulsion, powered by a single nuclear reactor. The propulsion system integrates an OK-650 nuclear reactor, AEU steam turbine, a shaft and a propeller. The nuclear powered propulsion provides a submerged speed of 29kt and surfaced speed of 15kt. The submarine has an endurance period of 100 days.

Trident II missile,Usa

UGM-133 Trident II, or Trident D5 is a submarine-launched ballistic, built by Lockheed Martin Space Sustems  in Sunnyvale ,California , and deployed with the US and Royal Navies. It was first deployed in 1990, and is still in service.

Trident II was designed to be more sophisticated than Trident 1, and have a greater payload capacity. It is accurate enough to be used as a first strike  weapon. All three stages of the Trident II are made of graphite epoxy , making the missile much lighter than its predecessor. Trident II missiles are carried by US Ohio and British Vanguard-class submarines. USS Tennessee (SSBN-734)  was the first submarine to be armed with Trident IIs. Trident II missiles are currently carried by fourteen Ohio class and four Vanguard-class SSBNs. There have been 143 consecutive successful test flights  of the D5 missile since 1989, with the most recent being from  HMS Vigilan in October 2012.

The development contract for Trident II was issued in October 1983. The first Trident II launch occurred in January 1987, and the first submarine launch was attempted by Tennessee, the first D-5 ship of the Ohio class, in March 1989. The launch attempt failed because the plume of water following the missile rose to greater height than expected, resulting in water being in the nozzle when the motor ignited. Once the problem was understood relatively simple changes were very quickly made but the problem delayed the Initial Operational Capability (IOC) of Trident II until March 1990.
It is estimated that 540 missiles will be built by 2013. The Trident D5LE (life-extension) version will remain in service until 2042.

Purpose: Strategic Nuclear Deterrence
Unit Cost: US$ 30.9 million
Range: Varies, based on payload, but rumored to be up to 11,300 kilometres (7,000 mi)
Maximum speed: > 6,000 metres per second (22,000 km/h; 13,000 mph)
Guidance system: inertial , with Star-Sighting ; GPS experiments done but not deployed.
CEP: Requirement: 90–120 metres (300–390 ft).That demonstrated by flight tests is classified, but rumored to be significantly better.
Warhead (in USA usage only): nuclear MIRV  up to eight W88 (475 kt) warheads (Mark 5) or eightW76  (100 kt) warheads (Mark 4). The Trident II can carry 12 MIRV warheads but START 1  reduces this to eight and SORT  reduces this yet further to four or five.New START  provides for further reductions in deployed launch vehicles, limiting the number of Submarine-launched ballistic missiles (SLBM) to 288, and the number of deployed SLBM warheads to a total of 1,152.

Patriot Air-Defence System, United States of America

Patriot is a long-range, all-altitude, all-weather air defence system to counter tactical ballistic missiles, cruise missiles and advanced aircraft. Patriot (MIM-104) is produced by Raytheon in Massachusetts and Lockheed Martin Missiles and Fire Control in Florida.
As well as the US, Patriot is in service in Egypt, Germany, Greece, Israel, Japan, Kuwait, the Netherlands, Saudi Arabia and Taiwan.
Patriot missile systems were deployed by US forces during Operation Iraqi Freedom. The systems were stationed in Kuwait and successfully destroyed a number of hostile surface-to-surface missiles, using the new PAC-3 and guidance enhanced missiles.


Guidance enhanced missile (GEM-T) upgrade.

The Patriot missile is equipped with a track-via-missile (TVM) guidance system. Midcourse correction commands are transmitted to the guidance system from the mobile engagement control centre.

The target acquisition system in the missile acquires the target in the terminal phase of flight and transmits the data using the TVM downlink via the ground radar to the engagement control station for final course correction calculations. The course correction commands are transmitted to the missile via the missile track command uplink. The high-explosive 90kg warhead is situated behind the terminal guidance section.
The range of the missile is 70km and maximum altitude is greater than 24km. The minimum flight time is the time to arm the missile, which is less than nine seconds, and the maximum flight time is less than three and a half minutes.
Raytheon has developed the Patriot guidance enhanced missile (GEM-T), an upgrade to the PAC-2 missile. The upgrade involves a new fuse and the insertion of a new low noise oscillator, which increases the seeker's sensitivity to low radar cross-section targets.
The GEM-T missile provides an upgraded capability to defeat air-breathing, cruise and ballistic missiles, as a complement to the PAC-3 missile. The first upgrade forebodies were delivered to the US Army in November 2002.
By September 2010, a total of 1,000 Patriot missiles were upgraded for the US Army.
In July 2008, South Korea placed an order for 64 GEM-T upgrade kits. In April 2011, US Army Aviation and Missile Command awarded a $58.3m contract to upgrade 131 PAC-2 missiles to GEM-T missile configuration.
In July 2008, South Korea placed an order for 64 GEM-T upgrade kits.

Patriot advanced capability (PAC-3) missile.

A new Patriot advanced capability (PAC-3) missile has increased effectiveness against tactical ballistic and cruise missiles, through the use of advanced hit-to-kill technology. Lockheed Martin is the prime contractor, with Raytheon the systems integrator. The PAC-3 has a Ka-band millimetre wave seeker developed by Boeing.
The missile guidance system enables target destruction through the kinetic energy released by hitting the target head-on. 16 PAC-3 missiles can be loaded on a launcher, compared to four PAC-2 missiles.
PAC-3 entered low rate initial production in late 1999 and first LRIP production missiles of a total of 92 were delivered in September 2001. A contract for 88 missiles was placed in December 2002 and another for 12 in March 2003.
The missile was first deployed during Operation Iraqi Freedom in March / April 2003. In February 2004, Lockheed Martin was awarded a production contract for 159 PAC-3 missiles, which includes 22 missiles to replace those expended in Iraq. Deliveries were concluded by April 2006.
A further contract for 156 missiles was received in February 2005. Of these missiles, 32 are for the Netherlands and 16 for Japan, under foreign military sales (FMS) agreements. The Netherlands received the first PAC-3 missiles in October 2007. The US Army ordered another 112 missiles in May 2006 and 112 in March 2007.

PAC-3 missile segment enhancement (MSE)

The PAC-3 missile segment enhancement (MSE) is part of a spiral development being undertaken by Lockheed Martin.
The increased range MSE gives the missile a more powerful rocket motor for added thrust and larger fins for increased manoeuvrability against faster and more sophisticated ballistic and cruise missiles. The MSE began flight testing in May 2008.
The PAC-3 MSE is the baseline interceptor for the multinational medium extended air defence system (MEADS) under a contract placed in February 2008. The missile was successfully test fired using the Patriot system in May 2011. Lockheed Martin was awarded a $68.9m contract in July 2012 to prepare the PAC-3 production line for the PAC-3 MSE missile.
The PAC-3 MSE successfully destructed a tactical ballistic missile (TBM) target at White Sands Missile Range in December 2012.

M901 launching station

The M901 launching station transports, points and launches the Patriot missile. Each launcher has four missiles. The launcher is remotely operated via a VHF or fibre-optic data link from the engagement control station, which provides both the missile prelaunch data and the fire command signal.

Engagement control station

The AN/MSQ-104 engagement control station is the only manned station in a Patriot fire unit. The control station communicates with the M901 launching stations, with other Patriot batteries and the higher command headquarters.
The control station is manned by three operators, who have two consoles and a communications station with three radio relay terminals. The digital weapon control computer is located next to the VHF data link terminals.

 Radar on the air defence system

The AN/MPQ-53 phased array radar carries out search, target detection, track and identification, missile tracking and guidance and electronic counter-countermeasure (ECCM) functions. The radar is mounted on a trailer and is automatically controlled by the digital weapons control computer in the engagement control station, via a cable link. The radar system has a range of up to 100km, capacity to track up to 100 targets and can provide missile guidance data for up to nine missiles.
The US Army Patriot radars are being upgraded by Raytheon. The upgrade kits provide greater power for the radar and the addition of a wideband capability for improved target discrimination.
A target engagement can be carried out in manual, semi-automatic or automatic mode. When the decision has been made to engage the target, the engagement control station selects the launch station or stations and pre-launch data is transmitted to the selected missile. After launch, the Patriot missile is acquired by the radar.
The command uplink and the TVM downlink allow the missile's flight to be monitored and provide missile guidance commands from the weapon control computer. As the missile approaches the target, the TVM guidance system is activated and the missile is steered towards the target. A proximity fuse detonates the high-explosive warhead.

Topol M, Russia

Topol-M (Nato code name: SS-27) is an intercontinental ballistic missile (ICBM) in service with the Russian strategic rocket forces (RVSN). It was developed by the Moscow Institute of Thermal Technology (MITT) and is an upgraded version of the RS-12M Topol missile.
 Topol-M is the first ICBM developed by Russia after the breakup of Soviet Union. The missile is being launched from underground silos. The Russian Army plans to deploy about 300 missiles on transporter erector and launcher (TEL) vehicles too.
Two Topol-M silo-based missile systems were deployed in December 2010 in the Tatishchevo Missile Division near Saratov in southwest Russia.
About 52 silo-based and 18 mobile Topol-M missile systems were in service as of January 2011. A total of 450 to 500 missiles are expected to be deployed between 2015 and 2020.

Topol-M ICBM development

The development of Topol-M was initiated by the MITT and Yuzhnoye Design Bureau in late 1980s. The Ukrainian firm Yuzhnoye withdrew from the programme and all documentation was shifted to MITT in 1992, following the dissolution of the Soviet Union.
The missile development was consolidated inside Russia. The programme was approved by the Russian government in 1993. The producers consortium led by MITT included about 500 Russian firms. The final assembly was made at the Votkinsk Mechanical Plant.
The first missile was test fired in December 1994. The first silo-based regiment was declared operational in 1998. The system was officially accepted into service in April 2000.
The first test of the mobile launcher was conducted in April 2004. The first flight version of the missile was delivered to the Russian Federation in 1995.
The first three mobile Topol-M missile systems entered service with a missile unit stationed near the town of Teykovo in December 2006. RS-24, a multiwarhead variant of Topol-M missile, was test fired from the northern launch site in May 2007. The missile variant is capable of carrying multiple independently targetable re-entry vehicle (MIRV) warheads.

Topol-M intercontinental ballistic missile system features

The Topol-M is a three-stage solid-propellant ICBM. It carries a single nuclear warhead under US-Russian arms control treaties. The design can support MIRV warheads. The missile can reach a range of 11,000km at a speed of 17,400km/h.
The missile is cold launched using a special booster called PAD which allows the first stage to fire into air by pushing out the missile from the storage container. The motors for the first stage were developed by the Soyuz Federal Centre for Dual-Use Technologies.
Topol-M is directed by autonomous digital inertial navigation system using an onboard GLONASS receiver. The burn time of the engine was minimised to avoid detection by the present and future missile-launch surveillance satellites during boost phase. The missile carries targeting countermeasures and decoys.
It can perform evasive manoeuvres in terminal phase to avoid the hit of interceptor missiles. The flat ballistic trajectory of the missile complicates the interception by the anti-ballistic missile (ABM).
The missile is shielded against radiation, electromagnetic pulse (EMP) and nuclear blasts, and can withstand a hit from laser technology.

Missile launch platform

The silo-based missile deployment site includes ten isolated silos. The underground silos were originally developed for R-36M and UR-100N missiles. The high cost elements such as protective covers and control systems were retained with minor changes. The missile uses the existing launch control and communication systems.
The underground site consists of a command and control bunker, security, power supply and nuclear blast detection systems. The launch complex was designed to survive hits from high-precision conventional weapons.
The Topol-M mobile missile is fired from a transporter erector launcher (TEL) canister mounted on the MZKT-79921 cross-country, a modified eight-axle mobile launch vehicle. The TEL was developed by the Titan Central Design Bureau and produced at the Barrikady Plant.
The mobile launcher can launch the missile at any time, even on a rough terrain route. The chassis is fitted with jacks to level the launcher. The onboard gas and hydraulic systems maintain the elevation of the container.

Unha-3 Rocket,Nord Korea

The Unha or Eunha is a Nord Korean expendable carrier rocket, which partially utilizes the same delivery system as the  Taepodong 2 long-range ballistic missile.
Western analysts believe the Unha-3 is a hybrid of Soviet and Iranian design, derived from the Taepodong-2 missile that North Korea began developing in the 1990s, but which has never successfully launched. No one in the West knows how much of the latest rocket and its engines were actually built inside North Korea.
North Korea has been rolling out ballistic missiles since the 1970s, when it first got Soviet Scud-B launchers from Egypt in return for help in the 1973 Arab-Israeli war. The first North Korean-built missiles—essentially Scud copies—were developed in the 1980s and were called the Hwasong-5 and the Hwasong-6.
By 1990, North Korea had produced an upgraded version called the Nodong, which had a longer range and greater payload capacity. (It was the Nodong that alarmed the West on July 4, 2009, when North Korea fired off seven of them from its east coast.) Next came the two-stage Taepodong-1 rocket (using a Hwasong atop a Nodong), which could deliver a one-ton payload up to 1,500 miles.

 

In August 1998, in North Korea’s first orbital attempt, a Taeopodong-1 with an additional third stage lifted off with a small satellite called Kwangmhyongsong-1 (“Bright Star 1”). The launch failed when the third stage didn’t ignite. North Korea then began working on a successor missile, called Taepodong-2, which launched only once, in July 2006; the missile blew up 40 seconds after launch. (An additional missile, called Taepodong-X, has not been tested, and little is known about it.)

The 91-ton, 100-foot-tall Unha-3 is a slightly modified version of the Unha-2 that North Korea launched eastward in 2009, a liftoff condemned by the United Nations Security Council, which considered it a ballistic missile test and soon thereafter tightened economic sanctions on the country. That orbital attempt—North Korea’s second—also ended in failure when the rocket’s third stage failed to ignite and fell into the Pacific Ocean.
The Unha-3’s first stage, about eight feet in diameter, appears to be made of steel and weighs about 60 tons, says Wright. “We’re pretty sure the first-stage engine is a Soviet design,” a scaled up version of the engine used in the Scud-B design, he says. It burns kerosene and nitric acid. The first stage has four such engines that share a common fuel tank.
The slimmer second stage is “a much more advanced design,” Wright says, that is identical to the submarine-launched Soviet R-27 ballistic missile, called the SS-N-6 in the United States. That stage has three engines: a main one for propulsion and two smaller ones for steering. “It’s not clear to me that they know how to build that engine,” says Wright. It burns a toxic, volatile, clear liquid fuel known as UDMH (unsymmetrical dimethylhydrazine) and nitrogen tetroxide. The Soviets first deployed he SS-N-6 in 1968. North Korea got some in the 1990s and modified them for use as intermediate-range missiles.

 The third stage appears to be identical to the upper stage of the Iranian Safir-2 booster, which Iran used to put a small satellite into orbit in February 2009. The Safir-2 uses the small steering motors from the SS-N-6 for propulsion.

Function	Expendable carrier rocket
Manufacturer	Korean Committee of Space Technology
Size
Height	32.01 metres (105.0 ft)
Diameter	2.41 metres (7 ft 11 in)
Mass	85,000 kilograms (190,000 lb)
Stages	3

Launch history
Status	Active
Launch sites	Sohae,Tonghae
Total launches	3
Successes	1

First stage
Engines	4 Nodong 2-1
Thrust	1100 kN
Specific impulse	252 sec
Burn time	120 seconds
Fuel	IRFNA,UDMH

Second stage
Engines	unknown
Thrust	250 kN
Specific impulse	255 s
Burn time	110 seconds
Fuel	IRFNA / UDMH

Third stage
Engines	unknown
Thrust	54 KN
Specific Impulse	230 sec
Burn time	40 seconds
Fuel	Unknown