[News Terms] North Korea's Hwasong-18 Launch Method 'Cold Launch'

'Cold launch' is a launch method in which a ballistic missile (ICBM) is propelled to a certain height by high-pressure, high-temperature gas generated from a gas generator built into the launch tube, and then the propulsion engine is ignited in mid-air to fly. It is a key launch technology for submarine-launched ballistic missiles (SLBM), which are ejected out of the water before ignition.

The SLBM launch process proceeds through stages such as booster ignition, main engine ignition, long-distance flight, and impact after the cold launch. Since the missile must be pushed into the air first without ignition and then ignited, advanced technology is required. Only seven countries? the United States, Russia, China, the United Kingdom, France, India, and South Korea?possess this technology, and there is analysis suggesting that North Korea may have tested this technology this time.

North Korea's Korean Central News Agency reported on the 14th that it successfully test-fired the 'Hwasong-18'. The Hwasong-18 launched this time is observed to be the first ICBM to apply the cold launch method.

The scene of the intercontinental ballistic missile (ICBM) 'Hwasong-17' launch, revealed by North Korea on the 17th of last month.
[Photo by Yonhap News]

This demonstrated a method where the missile engine ignites in mid-air immediately after launch from a mobile launch vehicle (TEL), not an SLBM. ICBMs are generally launched using the 'hot launch' method. The existing Hwasong-17 was launched by the hot launch method, igniting the engine at the moment of launch.

Experts analyze that North Korea used the cold launch method because the existing hot launch method involves ignition and strong thrust of a solid engine, which could damage the TEL due to shock at launch.

The TEL of this new solid-fuel ICBM has 18 wheels, nine on each side, and it is expected that if launched by the hot launch method, the TEL would have flipped over or broken. When our military revealed the 'monster missile' Hyunmoo launch last year, the cold launch method was also used to ensure the TEL could withstand the load.