Less than a month after UN Security Council adopted new sanctions against North Korea and just eight days after the New York Times featured an analysis claiming that Pyongyang had sourced the engines for its new liquid-fueled intercontinental-range ballistic missiles (ICBM) in the former Soviet Union (it likely did not), North Korean leader Kim Jong-un visited a chemical materials institute.
Officially described as the Chemical Material Institute of the Academy of Defense Science, Kim’s visit earlier this week was likely intended to demonstrate that North Korea is no longer the kind of perpetually underestimated “fourth-rate pipsqueak power,” as former U.S. President Richard Nixon once put it. (The two ICBM flight-tests in July, apparently, were insufficient in driving home this point.)
Instead of importing its inventory of advanced ICBM engines from abroad and instead of being unable to perfect critical technologies like reentry vehicle nosecones, Kim’s visit sought to demonstrate that North Korea was doing just fine manufacturing advanced composite materials for use in its ballistic missiles right at home — all this despite ever-extensive sanctions against the country.
A release in North Korea’s state-run Korean Central News Agency (KCNA) detailed Kim’s inspection of the facility. Additionally, KCNA released ten images of Kim’s activities at the institute.
According to KCNA, while at the facility, Kim “learned about the processes for manufacturing ICBM warhead tip and solid-fuel rocket engine (sic).” One accompanying image showed Kim holding and examining what appeared to be a nosecone for a ballistic missile reentry vehicle.
Kim additionally examined various processes associated with carbon fiber and wound filament rocket casing manufacturing — comparatively advanced technologies to what North Korea has been using to date that will one day facilitate the development of better-performing liquid fuel missiles and larger solid fuel missiles. Pyongyang currently has two strategic missile systems that use solid propellants — the Pukkuksong-1 (KN11) submarine-launched ballistic missile and the Pukkuksong-2 (KN15) medium-range ballistic missile (MRBM), a land-based version of the SLBM, effectively. (Solid propellants are also, as expected, used in many of North Korea’s close-range ballistic missiles and surface-to-air systems.)
KCNA’s associated images showed Kim examining various displays and machines related to this kind of indigenous manufacturing. If there was a message for the outside world from this visit, it was likely that North Korea not only can manufacture its liquid propellant engines at home, as the United States intelligence community already suspects, but it can also manufacture advanced materials that will ensure that the Hwasong-12 (KN17) intermediate-range ballistic missile Hwasong-14 (KN20) ICBM first test in July are merely the start of what could be a diverse and deadly suite of long-range missiles.
One image from KCNA’s release of ten (pictured above) from this visit stood out to long-time North Korea watchers, who immediately took notice on Twitter. In this image, Kim Jong-un is seen standing in a room at the Chemical Material Institute, flanked by two graphical displays.
One display contains the first known evidence of the existence of a missile known as the Pukkuksong-3 — the third in North Korea’s Pukkuksong (or ‘Polaris’) series of two-stage, solid-fueled missiles. From the display in the image, the Pukkuksong-3 appears to also be a two-stage, solid-fuel missile, likely destined for use on board the Gorae-class submarine at the Sinpo shipyard.
The existence of a new North Korean submarine-launched ballistic missile is not surprising. U.S. government sources with knowledge of the latest intelligence on North Korea’s ballistic missile programs told The Diplomat earlier this summer that North Korea had carried out repeated land-based ejection tests at the Sinpo shipyard. Four known tests took place on May 30, July 18, July 25, and July 30, for example.
The ejection tests may not have involved the Pukkuksong-3 itself, which may remain a developmental concept. However, one source told The Diplomat that U.S. military intelligence identified a new launch tube at the Sinpo shipyard, near the Gorae-class submarine.
North Korea likely has changes planned for the launch tubes on its lone ballistic missile submarine and may intend to test this new system soon. Earlier in August, prior to North Korea’s threats against Guam, U.S. government sources had told The Diplomat that a new SLBM flight test was assessed to be likely. Activity at Sinpo, however, has comparatively cooled down in recent weeks compared to earlier this summer.
The Pukkuksong-3, if it uses advanced materials including wound filament casing like that seen on a Pukkuksong-1 mock-up at North Korea’s April 15 parade, could demonstrate significantly greater performance. It remains unclear if North Korea has modified the casing for its existing inventory of Pukkuksong-1 and Pukkuksong-2 solid fuel missiles, both of which could see range extensions with more efficient airframe materials.
The potential existence of a Pukkuksong-3, assuming North Korea’s poster wasn’t intended as disinformation, is bad news. If Pyongyang keeps to the trend so far with its Pukkuksong series, we may see a Pukkuksong-4 one day — a solid fuel, canisterized, two-stage sibling with potentially intermediate-range capabilities. Indeed, the survivability advantages of solid fuel missiles on land, combined with North Korea’s newfound ability to manufacture integrated transporter-erector-launcher chassis indigenously, make this logic compelling for Pyongyang.
What’s potentially worse news than the existence of a Pukkuksong-3 SLBM, however, is found on the other wall in that same image. Under Kim Jong-un’s literal shadow on the opposite wall, we can see a diagram outlining the Hwasong-13 — a three-stage ICBM. If that designation sounds familiar, it’s because the missile may not be new at all.
The Hwasong-13 was first paraded in 2012 and came to be known by the United States intelligence community as the KN08. Its parade configuration was a three-stage design, assumed at the time to be based on a liquid propellant design. North Korea introduced a second missile known as the Hwasong-13 (the Hwasong-13 mod 2; erroneously called the Hwasong-14 by some sources prior to the July 2017 ICBM’s introduction) at a parade in 2015.
The diagram seen next to Kim in the image released this week could be the older three-stage liquid fuel KN08 ICBM or it could be a newer mod, based on a solid fuel design for the three stages. North Korea has used the name Hwasong-13 for different ICBMs already and the institute where Kim examined this diagram did specialize in solid propellants.
Moreover, at this year’s parade on April 15 in Pyongyang, North Korea showed off four of its China-sourced WS51200-based transporter-erector-launchers featuring ICBM-sized canisters and a separate mobile-erector-launcher (MEL) also featuring an ICBM-sized canister resembling China’s DF-31.
Analysts were divided over whether these systems were simply empty mock-ups, designed to suggest a level of sophistication that North Korea’s program was still far from reaching; but now, it appears that the programmatic aspirations represented in those massive ICBM canisters are very much a part of North Korea’s near-term ballistic missile development plans. (One of the MELs was seen again, with Kim Jong-un, in a slideshow on North Korea’s ballistic missile program shown at a concert to celebrate the first Hwasong-14 ICBM launch this year.)
Even if the missile on that diagram is just the older liquid-fueled KN08, this week’s image serves as some evidence that North Korea remains interested in that missile, which has yet to see flight testing. In other words, despite the successful flight testing of the Hwasong-14, North Korea has not given up on or deprecated its older ICBM design. Instead, it may look to field a diverse arsenal, comprising multiple ICBMs. Before this image, the last serious evidence that the KN08 was still an active program came in April 2016, when North Korea tested a large liquid propellant engine that has yet to be seen in any ballistic missile, but appeared compatible with the KN08.
All this does raise one question: why would North Korea, a resource-constrained new nuclear state, continue to pursue two different liquid-fueled ICBM designs when just one done well and deployed widely would do for deterrent purposes? The answers are left open to speculation for now.
There could be a mundane bureaucratic explanation, such as the existence of competing teams of scientists and engineers vying for Kim Jong-un’s approval. Alternatively, there could be a technical explanation. Perhaps North Korean engineers working with the RD-250-variant engine found in the Hwasong-14 experienced breakthroughs while Hwasong-13 development stalled. Either way, the Hwasong-14 emerged seemingly out of the blue this year, catching analysts off guard while the Hwasong-13 is a familiar face.
Solids Are Hard
The sliver of good news here is that large solid propellant ballistic missiles are remarkably difficult to do well and reliably, even if North Korea is showing signs of having overcome some of the more difficult obstacles already. Unlike liquid propellant missiles, solid fuel is cast directly into the rocket casing, requiring the casing itself to withstand far greater stresses than would be necessary with a liquid propellant design, where the fuel and oxidizer burn in a contained combustion chamber.
Additionally, while solid fuel confers important survivability advantages and enables exceptional mobility, poorly manufactured solid fuel rockets can fail at unacceptably high rates for the user. Errors during the casting process can introduce small “bubbles” or cracks into the propellant grain ensuring catastrophic failure during flight.
Moreover, changes in temperature during storage of even well-cast solid propellant can introduce warping. Finally, environmental shocks in handling and moving these missiles can also introduce problems.
These problems were well-known to the Soviet Union, which mastered the kinds of advanced composite materials that North Korea is now exploring for its arsenal of road-mobile ICBMs. More experienced programs than North Korea’s continue to face challenges with solid propellant missiles too. Consider that just earlier this year, even India saw one of its Agni-II solid-fuel medium-range ballistic missiles fail early in flight, likely due to problems with the propellant grain in the specific unit chosen for flight trials.
What the Future Holds
None of this is to underestimate North Korea, however. If the past 30 months of developmental activity in their ballistic missile program have taught us anything, it’s that North Korea can and will cross important milestones sooner than the outside world might think they would. That’s perhaps the “surprise” in all of the above: not that North Korea is looking into long-range solid propellant systems, but that it may be considerably further along than many thought.
While the above analysis may seem in-the-weeds on the technical details of North Korea’s ballistic missile program, this kind of programmatic signaling has value for Pyongyang. North Korea is seeking an opening with the United States for comprehensive talks and has laid the groundwork for an opening most recently with an attempt at coercive bargaining by threatening a strike at the waters near Guam.
By any measure, these images of Kim inspecting an institute specializing in solid propellants and wound filament missile casings serve a similar purpose: North Korea demonstrates a credible interest in high-performance, long-range, solid fuel rockets.
If Kim Jong-un is allowed to proceed uninhibited, he will soon, no doubt, begin testing both more advanced solid-fuel SLBMs and, eventually, ICBMs, rendering the already unacceptably risky task of preemption by South Korea and the United States entirely unrealistic.
And so, there’s a simple bottom line to all this from Pyongyang’s perspective: the United States should talk to us soon, before we figure out how to operationalize a more capable solid fuel missile-based nuclear force capable of striking U.S. forces in the region and, eventually, the U.S. homeland.