North Korea’s continued development of nuclear weapons and ballistic missiles remains a serious national security and foreign policy challenge for the United States. Recently unveiled weapon systems demonstrate North Korea’s continued progress in the development of its arsenal of intercontinental ballistic missiles (ICBMs), even as a lack of testing makes it difficult to clearly determine the extent of its progress. North Korea has previously tested other ICBM models, however, allowing for some insight into the capabilities of at least a portion of its ICBM arsenal while also providing an opportunity to examine the DPRK’s ability to improve its missile capabilities.
North Korea has to date conducted three ICBM tests, all of which took place in 2017, the first two of which involved tests of its Hwasong-14 model ICBM. The Hwasong-14, tested first on July 4 and again on July 28, represents the first North Korean ballistic missile that is clearly capable of striking the U.S. homeland. Based on its performance during the initial test, analysts assessed that the Hwasong-14 likely possessed a range of between 6,000 and 8,000 km. Following the missile’s second test, however, analysts upped their estimates of the Hwasong-14’s range to as much as 10,400 km, allowing it to potentially reach both Washington, D.C. and New York City. Others have suggested that the Hwasong-14’s effective range is more likely somewhere between those estimates, leaving it capable only of striking targets on the west coast.
The Hwasong-14 appears to be a two-stage version of the Hwasong-12 intermediate-range ballistic missile (IRBM), with the first stage powered by a single-engine alongside four additional steering engines. The missile’s engine is likely based on the Soviet-era RD-250 engine. The Hwasong-14’s second stage closely resembles the upper-stage of North Korea’s Unha 3 Space Launch Vehicle that is powered by engines resembling those on the Soviet R-27 missile, and it is clear that there were changes made to the missile’s second stage between the first and second test launches; most notably, this includes the addition of maneuvering thrusters.
North Korea’s third ICBM test took place on November 28, 2017. This time, the test was of the Hwasong-15 model ICBM. Based on the tests, analysts determined that the missile likely could have achieved a range of up to 13,000 km; depending on the weight of the missile’s payload, this would put the entire U.S. mainland within range. The Hwasong-15’s first stage is again powered by Soviet RD-250-like engines, though the Hwasong-15 appears to mount two such engines compared to the Hwasong-14’s one. The Hwasong-15’s second stage also received an upgrade and is powered by four of the engines derived from those on the Soviet R-27 – as opposed to just two on the Hwasong-14 – providing a much-needed boost to the missile’s second stage. Furthermore, at roughly 21-22.5 meters in length with a diameter of 2-2.4 meters, the Hwasong-15 is noticeably larger than the Hwasong-14, which measures 19.8 meters in length and 1.85 meters wide.
Comparing the Two:
The Hwasong-15 represents a significant step forward for North Korea’s ICBM capability when compared to the Hwasong-14. Most obvious is the improvement in range: while analysts disagree about the Hwasong-14’s range and its ability to strike major U.S. targets, analysts are in agreement about the Hwasong-15’s ability to range the entirety of the U.S. mainland. Additionally, the Hwasong-15’s larger size should allow it to carry an increased payload compared to the earlier model, and analysts estimate that it could likely mount a 1,000 kg payload without sacrificing the ability to strike anywhere in the United States. The Hwasong-15 is also likely capable of incorporating decoys and other systems designed to help the missile penetrate U.S. ballistic missile defenses, while the missile could also be fitted with a post-boost control system that would help to improve the missile’s accuracy.
It is also worth comparing the reentry vehicles (RVs) mounted on the Hwasong-14 and the Hwasong-15. Compared to the former, the latter missile was tested while carrying a blunter RV. A blunt RV moves through the atmosphere at a reduced speed compared to thinner RVs, thereby reducing the heat and stress placed on the warhead. The reduced speed, however, results in lower accuracy, and it is likely that North Korea’s long-range missiles equipped with blunt RVs will only be accurate in the tens of kilometers. This would make it difficult for such missiles to reliably strike precise military targets, but would be less relevant if North Korea instead chose to target a large population center. Reports about the RV carried on the tested Hwasong-15 differ, with some indicating the RV achieved a satisfactory level of performance and others suggesting that the RV did not survive reentry. If indeed the RV did not survive, the Hwasong-15’s size is such that North Korea can compensate by strengthening the RV without sacrificing range.
Comparing the Hwasong-14 and the more capable Hwasong-15 reveals the extent to which North Korea is able to quickly and successfully improve the design and performance of its missiles. This is particularly true when North Korea can benefit from extensive missile testing, and it has shown that it is more than capable of applying the lessons from those tests to future programs. It is important that North Korea be denied the opportunity to do so again.
Eli Fuhrman is an Assistant Researcher in Korean Studies at the Center for the National Interest and a current graduate student at Georgetown University’s Security Studies Program, where he focuses on East Asian security issues and U.S. foreign and defense policy in the region.