The Dong Feng-3 (DF-3, or CSS-2 in its U.S. DoD designation) is single-stage, liquid-propellant, medium-range ballistic missile (MRBM), capable of delivering a single 3 MT-yield thermal nuclear warhead over a distance of 2,800 km.
When the Chinese political leadership took the decision to embark on a strategic weapon programme in the 1950s, the Fifth Academy (Missile Design Academy) proposed an indigenous MRBM concept with an operational range of 2,000 km. The missile was given the designation Dong Feng-1 (DF-1). However, it soon became clear that such a missile was well beyond the country’s technical capability. As a result, the MRBM project was abandoned in 1962 and the DF-1 designation was later given to the Chinese copy of the Russian R-2 short-range ballistic missile.
With the successes in the reverse-engineering of the Russian R-2 and the development of the indigenous Dong Feng-2 (DF-2), Chinese missile engineers gained considerable knowledge and experience in rocket design. This paved the way for the introduction of a new MRBM concept. Relevant pre-search for the missile had been carried out at the Fifth Academy (Missile Design Academy) since August 1963.
Under the design concept, the missile was to be powered by four parallel chamber motors burning a bi-propellant with unsymmetrical dimethylhydrazine (UDMH) as fuel and red fuming nitric acid (HNO3) as oxidiser. The missile’s airframe was to be constructed from aluminium-alloy and the warhead from fibreglass, with a body diameter of 2.25 m. The propellant tanks were to be pressurised using heated nitrogen. The missile was to be controlled by either swinging nozzles (gimbaled thrust) or thrust vanes, with input from a cascaded compensation inertial guidance.
The Fifth Academy formally presented its MRBM design concept to the National Defence Science and Technology Commission (NDSTC) in October 1963, with the objective of fielding a nuclear-armed missile that could reach the U.S. bases in the Philippines. The design proposal was approved by the military in March 1964. Under the military’s new missile and rocket designation system, the MRBM was officially designated Dong Feng-3 (DF-3). Lin Shuang was appointed Chief Designer for the development programme in April 1964, with the aim to complete the missile’s detailed design in 1965 and the completion of the development around 1970.
The development of a new liquid engine burning the storable UDMH/HNO3 bi-propellant began as early as 1960, with relevant R&D facilities completed between 1962 and 1963. A new rocket engine testbed was completed in November 1964. The rocket engine, designated YF-2, consisted of four parallel YF-1 (5D10) chamber motors. The engine passed the 140-second ground test at the full-thrust of 106,000 kgf between April and June 1966. The entire development of the YF-2 engine took a total of six years, with 108 ground tests totalling 10,930 seconds.
Flight tests of the DF-3 missile began in late 1966. During the first test launch on 26 December 1966, one of the missile’s four chamber motors lost power at T plus 111.2 seconds. The warhead successfully landed in the impact zone, though the missile’s recoverable magnetic flight recorder was destroyed. The second test in January 1967 suffered a similar failure. The third test in May 1967 succeeded, with the warhead hitting the targeted impact zone. However, another engine failure occurred during the fourth test in June 1967.
To fully understand the root cause of these failures, a search team was sent to the target impact zone in the desert to retrieve the missile wreckages, which offered the design team valuable clues about the reasons of the engine failures. Improvements were made to Batch-02 of the missile, which was successfully test fired in December 1968 and January 1969. The missile carrying a dummy nuclear warhead was successfully tested in September to October 1969.
The DF-3 entered operational service in a small number in 1969, though the missile was not certified for design finalisation until August 1975. The development and test of the “524” thermal nuclear warhead completed in 1973.The development of the improved DF-3A began in 1981, with the objective of resolving the issues around poor engine reliability and simplifying the launch equipment. The DF-3A was first tested in 1984, with both of the two tests unsuccessful. The modified design was successfully tested in December 1985 and January 1986, and received design finalisation certificate in August 1988.
Stages:....................1 Overall length (m):........20.65 Wingspan (m):..............N/A Core stage diameter (m):...2.25 Take-off mass (kg):........N/A Take-off thrust (t):.......106 Thrust-weight ratio:.......N/A Maximum range (km):........2,660 km (DF-3) 2,810 km (DF-3A) Payload:...................Single 3 MT thermal nuclear or HE Propellant:................Liquid (UDMH/HNO3) Guidance:..................Inertial