The DF-2 (Dong Feng-2, NATO designation: CSS-1) is China’s first indigenously developed ballistic missile, with a maximum range of 960 km. An improved variant DF-2A with 1,200 km range was China’s first nuclear-armed ballistic missile.
The Fifth Academy of Ministry of National Defence gained considerable knowledge and experience in missile design through the development of the Soviet R-2 (SS-2 ‘Sibling’) short-range ballistic missile (SRBM) between 1958 and 1960. In late 1959, Chinese missile engineers proposed to increase R-2’s range from 590 km to 1,000 km by increasing its engine thrust and reducing its structural mass. The increase in range would be sufficient to allow the missile to hit targets in Japan.
At the same time, the Fifth Academy proposed a more ambitious medium-range ballistic missile (MRBM) with a maximum range of 2,000 km. Not able to choose between the two options, the academy decided to run two development programmes in parallel: a 2,000 km-range MRBM designated Dong Feng-1 (DF-1) and the 1,200 km-range SRBM designated Dong Feng-2 (DF-2). However, it soon became clear that the MRBM was too challenging and its development was abandoned. In August 1960, the Central Military Commission (CMC) officially approved the DF-2 design and tasked the Fifth Academy with the missile’s development.
The DF-2’s concept was developed by the First Design Department in March 1960. The concept envisaged a single-stage rocket 20.9 metres in length and 1.65 metres in diameter, with four delta-shape stabilising fins attached to the bottom of its body. The missile was to be powered by a single liquid engine that burns liquid oxygen as oxidiser and alcohol as fuel, giving a maximum thrust of 46 metric tons. The missile would weigh 29.8 metric tons when fully fuelled, and could reach a maximum range of 1,200 km. The guidance system and launch equipment were to be based on those of the R-2.
By modifying the airframe layout and replacing some steel structures with lighter aluminium alloys, Chinese missile engineers were able to reduce the ratio of the missile’s structural mass to its gross mass (structural coefficient) from 22% to 14%. The Third Design Department developed the 5D60 rocket engine based on the R-2’s 5D52 engine, with increased internal pressure and thrust. As the missile’s maximum velocity increased to 3.5 km/s, a more blunt nosecone made of heat-resistant fibreglass material was adopted to reduce the re-entry heat.
The DF-2 design was finalised in the spring of 1961 and the engineering development began thereafter. The first test launch was scheduled for October of the same year. However, the 5D60 engine did not pass its full-thrust ground test until November, which pushed the first test launch back by five months. Engineers and workers of the Fifth Academy and 211 Factory rushed to get the missile built in order to meet the deadline for the test launch. The first test missile rolled out of the production plant on 20 February 1962 and was delivered to the launch site on 4 March.
The test launch of the DF-2 took place on 21 March 1962 at the Northwest Missile Test Range (Jiuquan). The missile was launched at 09:05:53. Once several seconds into the flight the missile began to veer off course. The missile’s rocket engine then caught on fire and shut down. Soon the missile was in free fall and impacted the ground at T plus 69 seconds in a violent explosion, leaving a massive hole 4 metres deep, 22 metres wide in the ground not far from the launch pad.
The failure of the DF-2 test flight was a major setback in China’s ballistic missile programme. Post-mortem examination suggested that flaws in the missile’s airframe created an elastic vibration during the flight, which was amplified by the missile’s flight control system and led to the missile losing its control. In addition, the poorly designed rocket engine disintegrated under the vibration and led to it catching fire. The investigation also uncovered that the many corners were cut during the missile’s development in order to meet the tight deadline for the test launch. The rocket engine was not even fully tested on the ground before being certified for flight test.
The incident led to a complete overhaul of the design team, with Lin Shuang appointed the missile’s Chief Designer in September 1962. The military also agreed to temporarily lower their technical requirements, allowing the missile’s maximum range to be reduced to 960 km and the thrust reduced to 42.5 metric tons. The design team spent the next two years reviewing the missile’s design and validating its technologies. Finally, the redesigned DF-2 made its first successful flight in June 1964.
As the DF-2 did not meet the original technical requirements, it did not enter batch production. In early 1964, the Chinese leadership tasked the Fifth Academy with the development of an improved DF-2 as the delivery system for China’s nuclear weapon. The missile, designated DF-2A, would meet all original technical requirements including a maximum range of 1,200 km and engine thrust of 47.5 metric tons.
Another important improvement on the DF-2A was its guidance system. The original DF-2 inherited the guidance system of the R-2, which used an inertial gyroscope coupled with radio signal corrections. An antenna array had to be set up 20—30 km behind the launch site to send correction signals to the missile throughout its flight. The DF-2A featured a Chinese-developed full inertial guidance package, which significantly improved the missile’s accuracy and survivability.
The DF-2A made first flight successfully on 13 November 1965. A further seven flight tests were conducted over the following two months, six of which were successful.
On 27 October 1966, a DF-2A launched from the Jiuquan rocket range delivered a 12 kiloton atomic (fission) warhead over a distance of 894 km to the targeted impact zone in Lop Nor. The warhead successfully detonated 569 metres above the ground. This was China’s first and only missile-delivered nuclear test, demonstrating that the nuclear missile weapon system was ready for operational deployment.
The DF-2A achieved initial operational capability (IOC) in the PLA Second Artillery Corps (strategic missile force) around 1969 and was referred to by Western intelligence as CSS-1. The missile was withdrawn from service in the early 1980s.
|Number of stages||1|
|Flight range||1,200 km|
|Body length||20.9 m|
|Body diameter||1.65 m|
|Launch mass||29.8 t|
|Propulsion||1 x 5D60 rocket engine|
|Oxidiser||Liquid oxygen (LOX)|
|First flight||June 1964|