[Opinion] Questions on the Reliability of North Korea's Hypersonic Missiles and ICBMs

North Korea has already conducted 12 missile test launch provocations this year alone. The core among these is the test launches of hypersonic missiles and super-large intercontinental ballistic missiles (ICBMs), which are strategic tasks for defense capability development mentioned at the 8th Party Congress in January last year.

The hypersonic missiles launched on January 5 and 11 were equipped with a conical warhead, unlike the wedge-shaped warhead showcased in September last year, sparking controversy over whether they are maneuverable reentry vehicles. This is because conical bodies cannot achieve high lift characteristics at hypersonic speeds. Hypersonic missiles must be capable of performing erratic maneuvers through aerodynamic flight at speeds exceeding Mach 5 within the atmosphere to neutralize missile defense systems. Maneuverable reentry vehicles possess maneuvering capabilities between those of hypersonic glide vehicles and conventional ballistic missile reentry vehicles. However, without actual flight trajectory and performance data, clear distinction is limited. Despite this controversy, North Korea announced the completion of hypersonic missile development after only three test launches. China also conducted about ten test launches for a similar hypersonic missile using a medium-range ballistic missile as a booster. It appears they hastily declared the development complete without demonstrating full performance.

South Korea and the United States estimate that four test launches of new ICBMs have been conducted since February 27. Meanwhile, North Korea announced that missile launches on February 27 and March 5 were important tests for satellite communication devices aimed at reconnaissance satellite development. Globally, there has been no precedent for verifying performance by equipping satellite equipment on missile warheads. On March 6, the Rodong Sinmun reported that a space environment test facility is being constructed. This implies that, due to the absence of a ground-based space environment test facility, North Korea likely conducted space environment tests by placing satellite equipment into low Earth orbit via missile. This explanation is hardly plausible. Ultimately, it is a reasonable inference that new ICBM tests were conducted on February 27 and March 5. So what was tested? Since North Korea had no prior experience launching with four engines clustered together, it is believed they verified clustering technology including nozzle control.

The new ICBM launched on March 16 reportedly exploded in mid-air at an altitude within several kilometers during ascent. South Korea and the U.S. stated that they attempted a test launch of the Hwasong-17 ICBM, but North Korea made no comment on the failed missile. South Korea and the U.S. assess that the three new ICBM test launches were equipped with two sets of twin Paektusan engines (each set having four combustion chambers and nozzles) on the first stage.

Regarding the ICBM successfully launched on March 24, claims by North Korea and South Korea-U.S. differ, causing controversy. North Korea released footage the next afternoon and announced that the missile launched on the 24th was the Hwasong-17 ICBM. In contrast, South Korea and the U.S. evaluate it as the Hwasong-15, which was launched in November 2017. They argue that the peak altitude of 6,248 km was possible by reducing the warhead weight of the Hwasong-15 ICBM. Similar to the debate over whether the Pukguksong-1 submarine-launched ballistic missile was launched from a submarine or an underwater barge in 2016, this issue will remain unresolved. In the controversy over the Hwasong-17 ICBM, North Korea appears to be hastily rushing the strategic tasks promised in last year's project summary report.

The production of hypersonic missiles, ICBM reentry vehicles, satellite launch vehicles, and reconnaissance satellites requires enormous costs for developing and procuring various advanced materials and electronic equipment. To verify the performance of these weapon systems, numerous expensive ground test facilities and equipment such as hypersonic wind tunnels, plasma chambers, and thermal vacuum chambers are necessary. Due to ongoing sanctions, North Korea’s economic condition has deteriorated, making it difficult to develop, procure, or even establish ground test facilities. Ultimately, under these circumstances, developing reliable weapon systems is challenging. It appears that the emphasis is placed more on fulfilling strategic tasks rather than operational capability of weapon systems in wartime.

Jang Young-geun, Professor, Department of Aerospace Engineering, Korea Aerospace University