Half A Loaf: Third Hwasong-16 Solid IRBM Test Shows Booster is Ready but HGV Payload Needs Work
On January 6, North Korea test-launched a Hwasong-16B (HS-16B) solid-propellant intermediate-range ballistic missile (IRBM) carrying a hypersonic glide vehicle (HGV) payload. This was the third apparently successful flight of the HS-16 booster (two with HGVs, the other with a maneuvering reentry vehicle (MaRV) payload), probably meaning that the North considers the booster ready for operational deployment. The success of the HGV payload, however, cannot be confirmed, marking three apparently lackluster MaRV flights (one on a liquid booster); several successful flights over at least a few years probably will be needed before the HGV is ready for deployment.
The HS-16 would be deployable in the near-term with the previously-flown MaRV or a yet-to-be-seen traditional reentry vehicle. The North reported using “new composite carbon fiber material” in the HS-16 booster and updated guidance technology, but the nature of these improvements and their effect on system performance are unknown.
The latest test underscores North Korea’s continuing commitment both to IRBMs to strike Guam and other farther-flung theater targets, and to HGVs as an eventual means of further challenging US missile defenses in Guam and the western Aleutians. But the high cost of HGVs and the limited set of targets for which they offer comparative advantages (mostly key ground-based missile defense sensors) mean that relatively few will be deployed.
Information to Date
Japan’s Ministry of Defense reported on January 6 the launch that day of a ballistic missile from North Korea to the northeast, falling into the sea at a distance of about 1,100 km with a maximum altitude of about 100 km after about a ten minute flight. The South Korean military confirmed the range of what it termed a “midrange missile” but did not report the altitude, claiming that launch preparations had been detected in advance. (It is not clear whether this detection was in addition to the military’s December 23 warning that the DPRK could launch an IRBM with a hypersonic warhead around its end-of-year plenum.)
On January 7, North Korean press reported the previous day’s “test-fire of [a] new-type intermediate-range hypersonic ballistic missile” that demonstrated a “first peak height of 99.8 kilometers and the second peak height of 42.5 kilometers at the speed amounting to twelve times of the speed of sound, and accurately landed on the simulated target waters in the open sea 1,500 kilometers away.” This missile reportedly used rocket motors incorporating “a new composite carbon fiber material” and its guidance system included “a new comprehensive and effective method based on the already-accumulated technologies.” The test was said to have confirmed “the effectiveness of the missile system that fully meets the expected military specifications” and “the successful development of the new-type strategic weapon system.”
Accompanying photos and video showed the “cold launch” from a canister mounted on a seven-axle road-mobile launcher of a solid-propellant missile tipped with a wedge-shaped HGV payload. The images generally matched those of the HS-16B solid-propellant IRBM that was last launched on April 2, 2024 and also carried an HGV.
On January 7, the South Korean military characterized North Korea’s announced performance as an exaggeration, reporting that South Korea, Japan, and the US agreed the missile flew about 1,100 km with no second apogee (peak height) reached during the flight. The ROK military assessed the North’s claims as “highly likely deception.”
Analysis and Implications
The IRBM booster. This is the third apparently successful flight of the solid-propellant booster portion of the HS-16 system, including the April 2024 test and the January 2024 test that carried a MaRV rather than an HGV. (Moreover, the HS-16 booster is based on that of the HS-18 solid intercontinental ballistic missile [ICBM], which was tested successfully three times in 2024.) By traditional North Korean standards, that would be sufficient for the booster to be considered ready for operational deployment. This may be what the North was referring to in announcing “successful development” of the system.
The HGV payload. This is the third known test of the HGV, including on the April 2024 HS-16B test and a September 2021 flight on a version of the Hwasong-12 liquid-propellant IRBM booster that the North dubbed Hwasong-8 and later HS-12B. There is no clear open-source evidence that any of the three HGVs flew successfully after release from the booster. Indeed, reminiscent of the latest flight, the ROK in April 2024 claimed the US agreed with its assessment of a shorter range and fewer maneuvers than claimed by North Korea. If the US did in fact agree with the ROK assessments, then we can be highly confident the last two HGV flights failed given Washington’s substantial missile detection and tracking capabilities.
It should not be surprising that North Korea is struggling with the HGV. This is a very demanding technology given the need to cope with the temperatures and pressures of sustained hypersonic flight, which are compounded by the maneuvering needed to evade missile defenses (the comparative advantage of HGVs over other payloads), as well as the challenges of accurate guidance in such an environment. China and Russia needed numerous flight-tests over several years to successfully develop deployable HGVs, and the US is still working on it. Pyongyang likely has at least several successful flight-tests yet to go, even if it were to obtain assistance from Russia or China.
Although the HGV is clearly not ready for prime time, North Korea might choose for political and propaganda reasons, or in an effort to complicate allied planning, to claim the payload is deployed even if remains under development. (For example, North Korea released a photo in October 2024 in conjunction with Kim Jong Un’s visit to “strategic missile bases” showing Kim in an underground missile facility standing next to HGV-equipped HS-12B liquid IRBMs.[1]) In any case, the North could still deploy the HS-16 with the MaRV tested in January 2024, which was also flown twice on the “Hwasong-8” in January 2022, or with a traditional reentry vehicle that has yet to be seen on the HS-16.
Composite carbon fiber. There is no open-source information on the nature of the “new composite carbon fiber material” reportedly used “in the manufacture of the engine body of the missile,” much less on whatever material had been used previously. The North’s “engine” phraseology would seem to apply not to the body of the HGV payload, but rather to the solid booster motors. Use of a new motor case or nozzle material might explain why Pyongyang announced in March 2024 the conduct of “a ground jet test [static test] of a solid-fueled engine for a new-type intermediate-range hypersonic missile,” the reported success of which allowed “a timetable for completing the development of the new-type intermediate-range hypersonic missile weapon system” to be set.[2]
Composite materials incorporating carbon fiber — and there is no information on what proportion of the North’s new material is carbon fiber, or the quality of that fiber — generally are desirable because they can be stronger than other composites, provide equal strength with less weight, or some combination. Lower-weight motor cases or nozzles would permit using the energy of the solid booster to propel the payload farther, to loft a heavier payload, or some combination of the two. Although it is possible that the purpose of using a new material would be to strengthen the motor cases to permit putting the booster into more stressful flight trajectories, it is at least as likely that the original HS-16 booster was sufficiently sturdy to handle HGV flights (as North Korea did with that booster in April 2024) but Pyongyang now is looking to provide that sturdiness at lower weight and thus with more boost performance.
Improved guidance. Obtaining satisfactory accuracy while engaging in hypersonic maneuvers is one of the main challenges in HGV development, so it certainly makes sense that North Korea would want to improve its HGV accuracy. That said, there is no open-source information on what the guidance system or accuracy of the North’s previously-tested HGVs was, what technological improvements were made in the latest payload, or what effect those improvements had on accuracy. Indeed, given the apparently checkered flight-test history of its HGVs, Pyongyang itself may currently lack information on the degree of any improvement.
The Bottom Line
Although the latest HS-16B test underscores that the booster portion of the system probably is regarded by North Korea as ready for deployment, the HGV payload has several successful flight-tests and thus probably at least a few years to go. The nature and impact of the “new composite carbon fiber material” and updated guidance technology used in the latest test are unclear.
The test does show Pyongyang’s continued commitment to IRBMs, which pose a deterrent threat to US territory in Guam and the southwest Aleutians and can disrupt bases in Guam, the Philippines, and farther-flung reaches of Japan that could support US operations against North Korea. The test also shows continued commitment to the HGV development program, which if successful, will offer another means of combatting US missile defenses in Guam and the Aleutians. Moreover, the HGV is invoked by North Korea as a sign of technical sophistication (“a technical force which is by no means easy to achieve…a remarkable achievement” that only “a few countries in the world might possess,” as the media claimed on January 7) and of deterrent credibility and resolve (“through the current test…we… clearly showed the enemies what we are doing and that we are fully ready to use any means to defend our legitimate interests”).
Even if successful, the high cost of HGVs and the limited set of targets for which they offer comparative advantages (mostly key ground-based missile defense sensors) mean that relatively few will be deployed to fulfill niche roles revolving around missile defense suppression. The HS-16 likely will end up being deployed in larger numbers with MaRVs and perhaps even traditional reentry vehicles, especially if North Korea eventually develops sufficient accuracy to make conventionally armed IRBMs militarily feasible.
- [1]
“Respected Comrade Kim Jong Un Inspects Strategic Missile Bases,” Korean Central News Agency, October 23, 2024.
- [2]
“Respected Comrade Kim Jong Un Guides Test of Solid-fueled Engine for New-type Intermediate-range Hypersonic Missile,” Korean Central News Agency, March 20, 2024.