North Korea Tests Revolutionary New Solid Fuel Engine For Strategic Nuke-Carrying ICBMs: Why Does It Matter?

North Korea has tested a new missile engine which is expected to revolutionise the capabilities of its strategic nuclear deterrent, with the state run Korea Central News Agency (KCNA) reporting on December 16: “An important institute under the Academy of Defence Science succeeded in the static firing test of high-thrust solid-fuel motor with a thrust of 140tf, the first of its kind in the country, at the Sohae Satellite Launching Ground on the morning of December 15.” Chairman of the ruling Korean Workers’ Party Kim Jong Un reportedly personally guided the test, which had “the key goals for strengthened national defence capability set by the 8th Congress of the Workers’ Party of Korea (WPK),” which in January set out plans to strengthen strategic nuclear capabilities. The test follows multiple test launches of the latest ICBM the Hwasong-17, which is the largest road mobile missile in the world and is speculated to have the ability to deliver multiple warheads simultaneously to targets anywhere on the United States mainland. KCNA elaborated that the aim of the test was to verify “all technical specific features of the high-thrust solid-fuel motor based on the thrust vector controlling technology… this important test has provided a sure sci-tech guarantee for the development of another new-type strategic weapon system.”

North Korea began to field solid fuelled ballistic missiles in the early 2010s when it inducted the Hwasong-11 (KN-02 Toksa) ballistic missile into service – a very short ranged mobile tactical missile designed to support forces on the frontlines. This was followed by the Pukkuksong-1 submarine launched medium range ballistic missile, its land based counterpart the Pukkuksong-2, and multiple further Pukkuksong series submarine launched missiles for the country’s expanding strategic submarine fleet. From 2019 a series of much more capable solid fuelled tactical ballistic missiles began to enter service to succeed the Hwasong-11, and boasted new capabilities which made them extremely difficult to intercept for existing U.S. and allied air defence assets. Solid fuelled missiles have the advantage of being able to be stored fuelled and thus requiring considerably less time to launch, which is highly valuable for road mobile missiles particularly as North Korea’s arsenal is expected to be the priority target for by the massive air power of the United States, South Korea and their allies in the opening stages of any major war.

Adding solid fuelled intermediate and intercontinental range ballistic missiles to its arsenal would provide a major boost to North Korea’s deterrence capabilities and its ability to hold major American military facilities across the Pacific at risk. It would also complement other significant advances being made including the integration of hypersonic glide vehicles onto existing missile designs. The ability to strike American targets beyond Korea has long been highly prized by Pyongyang, in part due to the historical memory of the Korean War during which American aircraft based largely overseas levelled all major population centres in the country and were responsible for the bulk of the millions of civilian deaths which totalled an estimated 20-30 percent of the population. With Washington having seriously considered mass nuclear strikes on the East Asian state as recently as 2017, the ability to retaliate against the U.S. mainland in particular is considered vital to North Korea’s security.