What is the strength of "Dongfeng Express" that can deliver 12,000 kilometers in just 20 minutes?

On September 25, 2024, the Chinese People's Liberation Army Rocket Force successfully launched an intercontinental ballistic missile carrying a training simulated warhead in the relevant international waters of the South Pacific, and it accurately landed in the designated sea area with a range of about 12,000 kilometers, setting a record for the longest actual test of intercontinental missiles in the world. From launch to hitting the target, the entire process took only more than 20 minutes.

Image source: Baijiahao

According to high-definition pictures published by the People's Liberation Army Daily, this missile was confirmed to be a DF-31AG intercontinental strategic missile.

Image source: China Military

At present, there are only a handful of countries in the world that have the ability to develop intercontinental missiles, and only China, the United States and Russia have the technology to develop MIRVs. It is worth mentioning that since last year, the United States, the United Kingdom and Russia, the five permanent members of the United Nations, have successively tested intercontinental missiles, but all failed. The successful launch this time fully demonstrated China's strong military combat readiness.

01What is an ICBM? How powerful is it?

****Intercontinental Ballistic Missile (ICBM) is a long-range missile that can carry nuclear warheads or conventional warheads, mainly used for cross-continental strategic attack missions. As one of the core weapons of modern nuclear deterrence strategy, it has great destructive power. The main features are as follows:

Long range

Missiles with a range of more than 8,000 kilometers are called intercontinental missiles and have the ability to carry out missions across continents.

Schematic diagram of missile range classification in the INF Treaty

Image source: People's Daily Military Channel

Complex trajectory

After launching, an intercontinental missile enters the suborbital space outside the atmosphere, then returns to the atmosphere and falls rapidly to the target area by gravity. Its flight trajectory is parabolic , and it adjusts its attitude and changes its trajectory through interference measures.

High striking accuracy

Through technologies such as inertial guidance, astronomical guidance and satellite navigation, intercontinental missiles can accurately hit targets during long-distance flight.

Multiple Warhead Capability

Many intercontinental missiles are equipped with multiple independently targetable reentry vehicles, which can attack multiple different targets in one launch, greatly increasing the complexity and power of the attack. The Dongfeng-31AG intercontinental ballistic missile launched this time is China's first new solid-fuel long-range ballistic missile with independent high-mobility launch capability. It has strong concealment and can be deployed quickly; it has high anti-destruction capabilities and can carry up to 9 independently targetable nuclear warheads; its flight speed is as high as Mach 25 (25 times the speed of sound); its range is about 12,000 kilometers, which can cover the United States, Europe, Russia and other places, and has global strike capabilities.

Image source: China Military TV

The DF-31AG was unveiled to the public as early as 2017. Its successful launch this time proved its excellent stability and reliability, ensuring that my country has a strong security backing in a complex international environment.

02Why is it difficult to intercept an intercontinental missile once it is launched?

The reason why intercontinental missiles are difficult to intercept is mainly due to their high flight speed and complex flight trajectory. Its flight process is divided into three stages: boost phase (front stage), free flight phase (middle stage) and reentry phase (final stage).

Schematic diagram of intercontinental missile trajectory Source: Baijiahao

Boosting stage

The stage from the launch of a missile to its flight out of the atmosphere. During this period, the missile's propulsion system has just started to work, and its speed has not yet reached its limit. The missile's position and trajectory are more easily detected by radar and satellites. However, this stage only lasts for 3 to 5 minutes , and the launch point is usually far away from the enemy area, leaving the opponent with very little time to react. Therefore, even if the missile is detected, interception is almost impossible.

Free flight segment

The stage of missile flight outside the atmosphere. After the missile loses its propulsion power outside the atmosphere, it relies on inertia to fly along the trajectory. Since there is no air resistance, the missile flies very fast. The flight time at this stage can reach tens of minutes, which is theoretically a relatively possible opportunity for interception. However, the missile will use various interference measures , such as launching jammers, simulating warheads to confuse anti-missile systems, and changing its trajectory by constantly adjusting its own posture. If the Qian Xuesen trajectory is used (the missile glides and maneuvers outside the atmosphere), its unpredictability makes interception impossible.

Qian Xuesen's ballistic diagram Source: Baijiahao

Reentry

The stage when the missile re-enters the atmosphere is also the most destructive and difficult to intercept stage. The missile is extremely fast, reaching more than Mach 20, and it takes only a dozen seconds to reach the ground. Even the most advanced anti-missile missiles find it difficult to catch up. In addition, the missile will release multiple sub-warheads, each with an independent flight trajectory, which can attack different targets on the ground. The mixture of real and fake warheads and the complex trajectory further increase the difficulty of interception. Intercontinental missiles are extremely difficult to intercept throughout the flight process. It is difficult for existing anti-missile systems to respond in a short period of time, let alone effectively intercept.

03Dongfeng family, mission accomplished

The DF-31AG is a member of the "Dongfeng family". Speaking of the "Dongfeng family", everyone is familiar with it. It refers to the Dongfeng series of missiles independently developed by China . The series is famous for its high speed, high precision and strong strike power. It covers short-range, medium-range and intercontinental ballistic missiles. There are currently 15 members, each of whom is a "national heavy weapon". Although the DF-31AG is already very powerful, it is not the most powerful intercontinental missile in the Dongfeng family. The real "family boss" is the DF-5B and DF-41 . As the pioneer of China's intercontinental missiles, the DF-5 has been on duty for the motherland for many years. The DF-5B is an improved version of the DF-5. It was first publicly unveiled in 2015. Its biggest improvement is that it has the ability to independently guide missiles. The missile is 32.6 meters long and is a liquid-fuel, silo-launched heavy intercontinental missile with a range of 15,000 kilometers .

Image source: China Military TV

The DF-41 made its debut at the 2019 National Day military parade and is China's most advanced solid-fuel intercontinental ballistic missile . The missile is 16.5 meters long, has higher maneuverability and faster reaction speed, a range of more than 14,000 kilometers , can carry 10 independently targetable nuclear warheads, and has an explosive power equivalent to 200 Hiroshima atomic bombs. It is known as one of the most threatening strategic weapons in the world.

Image source: Xinhuanet

Looking back at the Dongfeng-5 intercontinental missile launched by my country for the first time in 1980, its range was only 9,000 kilometers. This time, the Dongfeng-31AG has a range of 12,000 kilometers, demonstrating the remarkable progress of my country's missile technology in the past 44 years. From the "follower" in the past to the "leader" today, my country has ranked among the world's top in many key areas. Whether it is 5G communications, aerospace, high-speed rail technology, or quantum technology and new energy vehicles, my country has achieved leapfrog development in just a few decades. The continuous growth and technological progress of the "Dongfeng family" is a powerful symbol of this huge transformation.

Author: Guo Weihong, PhD, Senior Engineer, University of Chinese Academy of Sciences

Planning & Editing: Little Dandelion