While launching of Elon Mask’s Space X was on the headlines everywhere recently, there was an important event slipping away from the attention worldwide: That was, China carried out its fourth ground-based midcourse missile defence interception test on February 6. The Ministry of Defence of China declared the test was within the Chinese territory and successful. China conducted three similar tests, in January 2010, January 2013 and July 2014.

The midcourse missile defence system, known as GMD, is primarily used to intercept incoming long-range (intercontinental) ballistic missiles. The flight of a ballistic missile is divided into three phrases which are boost, middle course and terminal (re-entry to atmosphere). The middle course is the most feasible but difficult phase to intercept a ballistic missile as it reaches its maximum speed and height.

Out in space more than 100 kilometres away from Earth, where has no air resistance, an intercontinental ballistic missile can reach 5,000 to 7,000 meters per second, or close to 15 to 20 times the speed of sound.

The missile defence systems such as Thaad (terminal high altitude area defence), RIM-161 standard missile 3 system, and the MIM-104 Patriot system are to intercept ballistic missiles at its terminal phrase just below or outside of the atmosphere.

Only a handful of countries have GMD systems and most of them have a limited scale. Russia has installed interceptor missiles to protect Moscow and its surrounding area. Japan, Israel, France and South Korea have limited GMD systems, mostly with the help from the US. India is also endeavour to build its own GMD.

Shao Yongling, a professor from university of People Liberation Army  Rocket Force, commented in a TV program that only the US and China has deployed middle course anti-ballistic missile system.

The US started to develop middle course missile defence capability much earlier than that of China. Apart from land based GMD that protects all of North America, the US also has the world’s most advanced sea-based Aegis missile defence system.

However missile interception is an untested technology. It is often compared to hitting one speeding bullet with another. It has become harder now as one incoming missile can carry more than a dozen warheads and alter its flight track or deploy various decoys to fool interceptors.

Even though being very difficult, the Chinese authority and military is determined to pool resources into missile interception. It is believed that further development of the technology and equipment not only will keep China in line with the US and other major powers in this field but also stimulate the development of a wide range of key technologies and industries related.

The Chinese government has repeatedly emphasised that the development of GMD system is not targeting any county as the system is of defence in nature. What China aims is to secure its capacity of nuclear retaliation. China will not first use nuclear weapons and will not take part in an arms race with any other country in the world.

Ren Zegang