Dong Feng-3 (CSS-2)

DF-3AThe Dong Feng-3 (DF-3, NATO code name: CSS-2) is single-stage, nuclear-armed medium-range ballistic missile introduced in the late 1960s. The missile remained in operational service with the PLA until the 2010s. A conventionally-armed version was exported to Saudi Arabia in 1987.

Background

By late 1959, development of Project 1059 Missile (R-2/SS-2) was near completion. Engineers at the Fifth Academy were ready to move on to their next project—an indigenously designed and developed ballistic missile. The Fifth Academy had originally proposed in 1958 a medium-range ballistic missile (MRBM) with a maximum range of 2,000—2,500 km. However, some in the Fifth Academy believed that the proposal was over-ambitious. Instead, they proposed to improve Project 1059’s engine performance, which would extend the missile’s range from 590 km to over 1,000 km.

Not able to reach a decision, leadership team of the Fifth Academy proposed to run the two projects in parallel: a 2,000 km-range MRBM designated Dong Feng-1 (DF-1), and a 1,200 km-range short-range ballistic missile (SRBM) designated Dong Feng-2 (DF-2). When this plan was submitted to Marshal Nie Rongzhen for approval in August 1960, Nie asked the Fifth Academy to take an incremental approach, with a model (Project 1059) in production, a model (DF-2) in development, and a model (DF-1) in pre-research. In October, the Central Military Commission (CMC) showed their support to the DF-2 by giving it top-priority go-ahead for development.

The original DF-1 MRBM development had stopped by 1962 due to financial and technical difficulties. However, development of the sub-systems including the 5D10 rocket engine and giro inertial guidance continued in the early 1960s. The Fifth Academy re-submitted its MRBM proposal to the National Defence Science & Technology Committee (NDSTC) in October 1963, with the objective of developing a missile that could reach the U.S. military bases in the Philippines. The CMC and NDSTC approved the new MRBM proposal and gave the missile a new designation Dong Feng-3 (DF-3), while the original DF-1 designation was reassigned to Project 1059 Missile.

Under the new design proposal, the DF-3 was to be powered by a cluster of four parallel rocket chamber motors, giving a takeoff thrust of 104 t. The missile was callable of delivering a three megaton thermal nuclear warhead over a maximum distance of 2,600 km, allowing it to strike any target in Asia. Western intelligence referred to the missile as CSS-2.

The DF-3 featured a range of new technologies, including the use of storable propellants, with red fuming nitric acid (HNO3) as oxidiser and unsymmetrical dimethylhydrazine (UDMH) as fuel. This allowed the missile to be fuelled in advance and remain in a ready-to-launch mode for hours or even days, thus lowering its chance of being detected by enemy surveillance and improving its survivability. The missile was also given a new cascade compensation inertial guidance system, which offered an estimated accuracy of 870 m CEP.

To collect flight parameters during atmospheric re-entry, a telemetry warhead was developed carrying a magnetic tape recorder, which is ejected for a soft-landing shortly before the ground impact. A ground tracking system known as the “150 System� was installed at the Jiuquan missile range to provide optical and radar tracking of the missile during the flight.

Out of the four DF-3 flights conducted between December 1966 and June 1967, three had failed due to the rocket engine losing propulsion on one of its chamber motors. To investigate the reasons for these failures, a team led by the Director of the 1st Academy Ren Xinmin went into the desert to search for the wreckages of the rocket engine at the impact zone. After 5 days of search, they successfully recovered the engine wreckage, which offered important clues for the design team to amend the engine design. The redesigned (Batch-02) DF-3 missile was successfully tested on 18 December 1968.

The DF-3 reached the initial operational capability in 1969, with a small number of the missile delivered to the PLA Second Artillery Corps. The flight test using a dummy nuclear warhead was carried out successfully in July 1970, though the development and tests of the “524� warhead was not completed until 1973. The missile was certified for design finalisation in August 1980. It was estimated that 150—200 missiles were in operational deployment.

The PLA initiated the DF-3 improvement programme in 1980, with the objective of resolving the issue of the rocket engine’s poor reliability and simplifying the missile’s launch equipment. The resulted DF-3A was first tested in 1984. However the first two flights in 1984 both failed. The modified design was tested again in 1985~86, with two successful tests. The DF-3A was certified for design finalisation in August 1988, with 50—100 missiles produced for operational deployment and export.

In 1987, China sold 30—120 DF-3A missiles with conventional warheads, as well as 9—12 launchers to Saudi Arabia. These systems were reportedly delivered in 1988, though no known test launch has ever been made in the country. It is not known whether these missiles are still operational.

Design

The DF-3 is 20.65 m in length and 2.25 m in diameter. The missile uses the YF-2 rocket engine, which consists of four 260kN-thrust YF-1 chambers motors placed in parallel. The engine burns a liquid-propellant with unsymmetrical dimethylhydrazine (UDMH) as fuel and red fuming nitric acid (HNO3) as an oxidiser. The missile uses a cascade compensation inertial guidance system, with an estimated accuracy of 870m CEP. The basic variant Dongfeng 3 has a range of 2,660km, and the improved Dongfeng 3A has a range of 2,810km.

The DF-3 was the first Chinese ballistic missile to be armed with a thermonuclear warhead. A single warhead with a designed yield of 3MT can be carried by the missile. Alternatively, the missile an be configured conventionally to carry a single high-explosive warhead. The missile is road-mobile on a carriage towed by 8×8 truck, and is launched from a pre-surveyed launch spot located near its base. The missile requires 2 hours for fuelling and preparation before firing.