DF-5

The Dong Feng-5 (DF-5, CSS-4) is China’s first true intercontinental ballistic missile, capable of reaching most parts of North America and Western Europe. The missile has also been developed into the Chang Zheng-2/3/4 families of orbital launch vehicles.

  • PLA designation: Dong Feng-5 (DF-5)
  • NATO code name: CSS-4
  • Type: Intermediate-range ballistic missile
  • Designer: China Academy of Launch Vehicle Technology (CALT)
  • Manufacturer: Capital Astronautics Machinery Co. (Factory 211)
  • Payload: Single 3.3 MT-yield thermonuclear (DF-5/5A); 3—6 MIRV of 1 MT-yield (DF-5B)
  • Range: 8,000—12,000 km
  • Propulsion: Two-stage liquid (N2O4/UDMH)
  • Guidance: Computer-platform inertial
  • Basing: Underground silo with ‘hot’ launch
  • In service: 1981
  • Status: Operational

Development History

Development of the DF-5 ICBM began in 1965, with the objective of fielding a true intercontinental-range missile system that could reach the targets in North America and Western Europe. The DF-5 development was headed by two Western-trained top Chinese rocket scientists: Tu Shou’e, who received a MSc degree from MIT, was responsible for the missile’s design. Ren Xinmin, who graduated from University of Michigan with both MSc and PhD, was in charge of the YF-20 liquid-propellant engine.

The goal of developing an ICBM as the nuclear delivery system was set very early on in China’s strategic weapon programme. The ICBM was first proposed by the Chinese missile industry as a long-term goal in 1958, though the actual development programme was not initiated until the mid-1960s. Following the early success in the indigenous ballistic missile programme, the Seventh Ministry of Machinery Industry (Ministry of Astronautics) drew up an ambitious plan to develop 4 ballistic missile models in 8 years (1965—1972), including the short-range DF-2A, medium-range DF-3, intermediate-range DF-4, and intercontinental range DF-5.

In March 1965, the Central Special Committee overseeing China’s missile and nuclear weapon programme approved the proposal to develop the DF-5 ICBM, with the first test launch set for 1971 and design finalisation 1973. The DF-5 was envisaged to be a two-stage rocket employing a 260 t-thrust engine on the first-stage and a 65 t-thrust engine on the second-stage, both burning the N2O4/UDMH bi-propellant. The National Defence Science Commission (NDSC) was responsible for building the missile test range and target impact zone. The China Academy of Sciences (CAS) was tasked with the development of the digital computer (Project 156) and fluid-suspended gyro-stabilized platform (Project 157) for the inertial guidance system.

The concept definition phase of the DF-5 programme concluded in January 1968, which kicked off the design phase of the programme. However, political turmoil of the ‘Cultural Revolution’ in the late 1960s and early 1970s, coupled with a string of unsolved technical issues, resulted in serious delay in the development programme. Between 1969 and 1970, the Seventh Ministry of Machinery Industry focused most of its resources on the CZ-1 launch vehicle and DFH-1 satellite projects, which led to further delay in the DF-5 programme.

Following the successful launch of the DFH-1 satellite in April 1970, the Seventh Ministry was finally able to give more attention to the DF-5 development. A campaign codenamed “705” was initiated in early 1970 to speed up the DF-5 development, with the objective to conduct the first test launch in October of the same year. However, normal development procedures were not being followed in order to meet the extremely tight timescale, resulting in poor production quality. The first missile was left in the assembly plant for several months after it was built, so that the engineers could carry out the ground testing of the missile’s guidance and control systems – a process that should have been done in the laboratory but was cut out in order to save development time.

DF-5 Design Features

The DF-5 was an entirely new missile with most of its technologies being newly developed. As a result, the DF-5 development team had to overcome a range of technical obstacles in its airframe, propulsion, guidance, and payload.

Body Diameter

The missile would be built in the assembly plant in Beijing and then transported in segments to the test centres and operational missile bases by railway. As a result, the missile’s body diameter must not exceed the maximum dimensions allowed for going through railway tunnels and bridges. After surveying the various railway bridges and tunnels in the country, the development team set the DF-5’s body diameter at 3.35 m.

Propellant Tanks

The propellant tanks of the DF-5 were constructed using the LD10 aluminium-copper alloy with grid stiffened reinforcement, which reduced the structural weight by 30%.

Propulsion

The DF-5’s first-stage propulsion (YF-21) consists of four parallel 65 t-thrust YF-20 engines. The second-stage propulsion (YF-24) consists of a 65 t-thrust YF-22 main engine and a YF-23 vernier engine. The latter was designed for steering and sustaining propulsion after the second-stage main engine cut-off, in order to enable a wide aiming arc for the missile’s warhead in the upper atmosphere. Both stages burn a liquid bipropellant with unsymmetrical dimethylhydrazine (UDMH) as fuel and nitrogen tetroxide (N2H4) as oxidiser.

The DF-21 engine was designed by the 11th Institute of the 1st Academy (CALT) in August 1965. The engine passed its first long-duration ground testing in February 1968. The engine’s testing and development was originally carried out at the 11th Institute in Beijing, but was transferred to Base 067 in Shaanxi Province in 1970.

Guidance

The DF-5 was the first Chinese ballistic missile to have adopted a ‘Computer-Platform’ inertial guidance system. The system utilises a fluid-suspended gyro-stabilized platform (Project 157), with gas bearing gyroscopes to achieve a high degree of accuracy. The onboard computer (Project 156) was China’s first integrated circus miniaturised computer, which became successful in the late 1960s.

Flight Control

With the increased size and weight, the DF-5 ditched the jet vane control used by previous Chinese ballistic missiles, and adopted swinging nozzles on its engines to control the flight of the missile.

DF-5 missile and re-entry vehicle

Design

The DF-5 consists of two stages connected by an inter-stage structure, all 3.35 m in diameter. Each stage has two propellant tanks: an oxidiser tank at the front and a fuel tank at the rear, connected by an inter-tank ring section. Oxidiser is pumped to the engines via a pipe penetrating through the centre of the rear fuel tank. The two propellant tanks and the inter-tank ring section form part of the vehicle’s thrust and weight bearing load structure and are constructed from high-strength aluminium-alloy LD10.

First-Stage

The first-stage comprises (from front to rear): oxidiser tank, inter-tank ring section, fuel tank, engine frame, and tail section. The front end of the forward oxidiser tank is protected by a fibreglass heat insulation layer to prevent damage from the high pressure and hot stream of engine exhaust from the second-stage engine during stage separation. The four main engine motors are mounted on the engine frame secured to the rear of the fuel tank. The frame transfers the thrust of the engines to the rocket’s thrust and weight bearing load structure. The stage is powered by the YF-21 module, which consists of a cluster of four parallel YF-20 single-chamber engines arranged symmetrically at an angle of 2°50’ to the axis of the core vehicle. Each motor has a swinging nozzle that can be pivoted up to +/-10° at radial direction to provide directional thrust and steering.

The tail section is a two-piece shroud 3.5 m in diameter and 2.4 m in length. It protects the main engines from aerodynamic forces and also houses engine components and linkages. A honeycombed fibreglass heat shield situated between the engine nozzles and the rear structure safeguards engine components and the fuel tank from the flames and heats of engine exhaust during launch. Four pressure relief valves regulate the pressure inside the shroud during flight. The erected missile is supported by four weight bearing points on the tail section, secured to the launch pad’s base unit with explosive bolts, which are detonated less than a second before the vehicle lifts off.

Inter-Stage Structure

The inter-stage structure comprises an inter-stage shroud and a grid structure. The inter-stage shroud, 3.35 m diameter and 3.2 m in length, houses second-stage engines to protect them from aerodynamic forces, and is connected to the rear of the second-stage’s fuel tank with explosive bolts. The grid structure, which consists of thirty-two 60 mm diameter metal bars, was designed to let exhaust gas from the engines on the second stage to escape. The rocket uses a ‘hot separation’ method, where the two stages are separated by the impingement of the hot exhaust gas jet from the second-stage engines. The engines ignite while the two stages are still connected, thus eliminating the need for jettisoning devices to provide the separation impulse and avoiding unpowered flight during the separation.

Second-Stage

The second-stage maintains the overall diameter of the first-stage at 3.35 m and comprises (from front to rear): instrument compartment, oxidiser tank, inter-tank ring section, and fuel tank. The engines are directly mounted on the rear of the fuel tank. The instrument compartment at the front houses the flight control system, navigation platform, and gas canisters. The stage is powered by an YF-22 main engine with fixed nozzle, and a swivelling vernier engine consisting of four YF-23 chamber motors. The swivelling vernier engine is designed for steering and sustaining propulsion after the main engine cut-off. The stage also has four small solid fuel rocket motors, which are fired for only half a second after the second-stage engine cut-off. This reduces the velocity of the rocket stage to allow the payload to be separated from the stage.

DF-5 re-entry vehicle
DF-5 re-entry vehicle
DF-5 re-entry vehicle being hoisted onto the missile

DF-5 Testing and Certification

The DF-5 testing consisted of both partial- and full-range testing. The partial-range testing was conducted within the Chinese territory, either using depressed trajectory from the Jiuquan missile test centre (Base 20), or elevated trajectory from the Taiyuan missile test centre (Base 25), with the missile flying westwards to its target impact zone in Xinjiang. The full-range testing was fired from Jiuquan to a target impact zone in the South Pacific.

To support the DF-5 testing, the Jiuquan missile test centre was added with new launch site (Launch Complex 2), target impact zone, telemetry and tracking system, and communication network, which became operational in the late 1960s.

To ensure the safety during the flight tests, the DF-5 missile was fitted with a self-destruction device, which could be triggered either by the onboard computer or remotely by the ground control.

DF-5 on launch pad at Jiuquan (Base 20)
DF-5 on launch pad at Jiuquan (Base 20)
DF-5 on launch pad at Jiuquan (Base 20)
DF-5 on launch pad at Jiuquan (Base 20)
DF-5 on launch pad at Taiyuan (Base 25)
DF-5 launch from surface launch pad in Taiyuan (Base 25)
DF-5 launch from surface launch pad in Taiyuan (Base 25)
DF-5 launch from underground silo at Taiyuan (Base 25)
DF-5 used as a satellite launch vehicle under the designation CZ-2

Batch-01 Testing

The partial-range flight testing of the DF-5 using depressed trajectory began in early 1971. The first test missile rolled out of the production line in March, but it took the engineers six months to fully test the missile and resolve the various teething issues before the missile was finally ready for launch. The first test launch took place on 10 September 1971. The missile flew normally for 207 seconds and completed main engine cut-off, first-stage jettison, and second-stage ignition as scheduled. However, the second-stage engine shut down earlier than scheduled due to an incorrect command from the onboard computer, resulting in the missile missing its targeted impact zone by 565 km.

The second DF-5 test launch on 26 December 1971 was aborted the last minute due to an engine failure. The missile was repaired and then launched on 8 April 1973, but lost control 43 seconds into the flight and was ordered to self-destruct. The root cause for both test failures was due to poor production quality.

The DF-5 testing was suspended after two unsuccessful flight tests, with the remaining 4 missiles converted into the CZ-2 launch vehicle to loft China’s FSW recoverable reconnaissance satellite. The first CZ-2 launch on 5 November 1974 failed, but the subsequent three missions in November 1975, December 1976, and January 1978 all succeeded with their payload placed into orbit.

Batch-02 Testing

The development of the DF-5 Batch-02 variant, which featured 10 major modifications in its design, began in January 1974. A total of 10 examples in the batch were produced, including 8 for the partial-range flight testing and 2 for the full-range flight testing. The testing began in 1978.

The first depressed trajectory flight test took place on 5 October 1978, with the missile successfully hitting its target zone, following by a second successful flight test on 5 April 1979. The two tests also allowed the engineers to collect valuable data on re-entry vehicle thermal proection and warhead detonation.

The flight tests from the Taiyuan missile test centre (Base 25) using elevated trajectory (high ballistic) began in early 1979, with the first test launch conducted successfully on 7 January 1979. This was followed by more tests from Taiyuan between June and November 1979.

Full-Range Testing

Preparation for the full-range flight testing codenamed “580 Mission” of the DF-5 began in early 1977, with the target to conduct the test launches by 1980. In February 1978, the mission planners confirmed that full-range testing would be conducted from the Jiuquan Satellite Launch Centre (Base 20) to the South Pacific, with a total distance of over 9,000 km. The target zone was a circular area 140 nautical miles in diameter, with its centre located at 7° S, 171°33’ E, between Solomon Islands, Nauru, and Tuvalu.

On 26 April 1980, a PLA naval task force consisting of two missile tracking instrumentation ships (Yuanwang 1 and 2), two communications relay ships (Xiangyanghong 5 and 10), eight Type 051 (‘Luda’ class) missile destroyers, rescue ships and tugs, totalling 18 vessels and 4 helicopters, left the Wusong Naval Base in Shanghai for the missile target zone in the South Pacific.

In the early morning of 18 May 1980, two fuelled DF-5 missiles stood on the two launch pads at Launch Complex 2 (North Launch Site) of the Jiuquan Satellite Launch Centre. The first missile (“580-A”) was launched at 10:00:23 local time. After flying for 29 minutes and 57 seconds over a distance of 9,070 km, the re-entry vehicle hit its targeted impact spot (7° 42′ 23” S, 172° 15′ 36” E), where it was recovered by the PLA naval task force. A second missile (“580-B”) was launched on 21 May at 11:19:32 local time. However, the second-stage of the missile was shut down 6.4 seconds early, resulting the re-entry vehicle missing its targeted landing spot by 1,400 km.

‘580 Mission’ launch preparation
DF-5 taking off from Jiuquan in full-range flight test
‘580 Mission’ flight path
Computer screen showing the flight trajectory in 580 Mission

Certification

The last Batch-02 test before operational deployment took place on 7 December 1981, with a modified DF-5 launched from an underground silo at the Taiyuan Satellite Launch Centre (Base 25) using an elevated trajectory.

The YF-20 rocket engine was certified for design finalisation in 1983. On 1 October 1984, three DF-5 missiles were shown for the first time during the military parade to mark the 35th anniversary of the founding of the PRC.

In July 1986, the DF-5’s warhead was certified for design finalisation. On 16 December 1986, the DF-5 received its certificate for design finalisation, ending its two decades of development.

DF-5 on display during the 1984 National Day military parade
DF-5 on display during the 1984 National Day military parade

Production

Between 1978 and 1981, 211 Factory and Base 062 produced a total of sixteen DF-5 missiles. Eight of these missiles were used for test launches and two delivered for operational deployment. The remaining six examples were converted into the CZ-2C launch vehicles for FSW satellite missions.

Between 1987 and 1989, Base 062 produced five DF-5 missiles in the Batch-03 standard for operational deployment. One of the missiles was test fired in Autumn 1989. This was also the last known DF-5 test launch. The remaining missiles were reportedly upgraded to the DF-5A standard in the early 1990s

Between 1994 and 1995, Base 062 produced eight missiles in the Batch-04 production, possibly in the improved DF-5A design.

Deployment

The exact number of the missile in service remains highly classified, and observer estimations vary significantly, ranging from less than 10 to over 30. According to some reports, by 2008 the DF-5 units in the PLA Second Artillery Corps (now PLA Rocket Force, PLARF) consisted of three launch brigades, each operating 6—10 missiles deployed in underground silos.

The 801st Brigade (cover designator: 96261 Unit), the oldest missile launch unit of the PLARF, is subordinated to Base 54. The brigade is based in Lingbao, Henan Province.

The 804th Brigade (cover designator: 96263 Unit), also subordinated to the 54 Base, is based in Luanchan County of Luoyang City, Henan Province. The brigade is believed to deploy 6—10 silo-based DF-5A ICBMs in the nearby Funiu Mountain.

The 803rd Brigade (cover designator: 96311 Unit), established in 1996 and subordinated to Base 55, is based in Jingzhou county of Huaihua City, Hunan province. The brigade has been undertaking operational duty since the late 1990s.

DF-5 deployment in underground silo

Variants

DF-5

The basic variant DF-5 had a maximum range of just under 10,000 km. The early DF-5 warhead does not have manoeuvre capability, so the re-entry vehicle would make an unpowered descent through the atmosphere to a pre-selected target on the orbital ground track. The estimated CEP for the warhead was over 1,000 m.

DF-5A

The improved DF-5A began development in the early 1990s, with the objective to field a missile with an extended range of 13,000 km, allowing it to cover most part of North America. The extended range was achieved by increasing fuel capacity and reducing the weight of the re-entry vehicle heat shield. Other improvements include an improved warhead with a reaction control system (RCS), which allowed the warhead to deviate from its re-entry trajectory to reach a selected landing site and achieve greater accuracy. The launch system was also redesigned to simplify the launch procedure and reduce launch preparation time.

The first flight test of the DF-5A using a depressed trajectory took place on 17 June 1993 from the Jiuquan Satellite Launch Centre. A second test using an elevated trajectory took place on 26 July 1995 from the Taiyuan Satellite Launch Centre. Both tests were successful, allowing the DF-5A to enter operational service.

DF-5A launch from Jiuquan (Base 20)

DF-5B

A U.S. report in 1999 suggested that the DF-5/CSS-4 may be fitted with 4—6 lightweight multiple independently-targeted re-entry vehicle (MIRV) warheads from the DF-31/JL-2 programme. However, it took over a decade before the missile was fully developed and tested. The MIRV variant, designated DF-5B, was first revealed to the public during the September 2015 military parade in Beijing to mark the 70th anniversary of the WWII victory.

The DF-5B is believed to be capable of carrying at least 3 MIRV warheads, which are housed inside a blunt payload fairing similar to that of the CZ-2C launch vehicle.

In February 2016, it was reported that older single-warhead DF-5 missiles were being retrospectively fitted with MIRV warheads, allowing China to increase the size of its nuclear arsenal without deploying additional missiles.1

DF-5B on display during the 2015 Victory Day military parade
DF-5B on display during the 2015 Victory Day military parade
DF-5B on display during the 2015 Victory Day military parade

DF-5C

In January 2017, it was reported that China carried out a test of the new DF-5C capable of carrying 10 MIRV warheads.2

Specifications

  • Overall length (m): 33
  • Core stage diameter (m): 3.35
  • Take-off mass (kg): 183,000
  • Payload mass (kg): 3,000

References

  1. Bill Gertz / The Washington Times. 2016. China adds warheads to older DF-5s. [ONLINE] Available at: http://www.washingtontimes.com/news/2016/feb/10/inside-the-ring-china-adds-warhead-to-older-df-5s/. [Accessed 25 September 2017]. []
  2. Bill Hertz / The Washington Free Beacon. 2017. China Tests Missile With 10 Warheads. [ONLINE] Available at: http://freebeacon.com/national-security/china-tests-missile-10-warheads/. [Accessed 25 September 2017]. []

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