Most of the news on the nuclear front is usually devoted to stuff pointed at the United States, rarely the other way around, and there was news on both fronts this week and guess which dominated the headlines?
So I am going toe the party line with this post and talk about Kim Jong Un’s visit to the Chemical Material Institute of the Academy of Defence Sciences. There are three things we can focus on; reentry vehicles, motor casings for solid fuelled missiles, and a depiction of the Hwasong-13 ICBM.
Of the three the latter entirely consisted of a poster, a fact that needs to be borne in mind. I’ll start with the Hwasong-13.
We’ve heard of the Hwasong-13 before, of course, what in US nomenclature is called the KN-08. The thunder of the KN-08 has been taken by the Hwasong-14, and like with the Musudan it disappeared off the analytical radar as a consequence. But Kim’s visit to the Chemical Materials Institute has brought the KN-08 back into relief.
The KN-08 was assumed to be a three-stage, road mobile, liquid fuelled ICBM, with the booster stage powered by two 4D10 engines (and verniers) derived from the Soviet R-27 (SS-N-6) SLBM. However, the development of the high thrust, 80 tonne, Pektusan or March 18 Revolution engine, the booster engine on the Hwasong-12 IRBM and Hwasong-14 ICBM, saw North Korea go down a different route. Take a look at this fuzzy image of the Hwasong-13 poster shown during Kim’s sojourn.
The booster stage looks like it features two engines, but it’s really hard to tell because of the resolution of the image. If so, I speculate, that the Hwasong-13 ICBM has been revived (or perhaps never abandoned) because, in part, North Korea wants to modify it by clustering two Pektusan engines, rather than two 4D10’s.
The second stage of the Hwasong-14 ICBM for the July 4 test was powered by two vernier engines, and the July 28 test by four vernier engines. The second stage of the Hwasong-13 depicted in the poster appears, again hard to tell so speculating, to be powered by the one engine. There have been reports of static ground testing of a relatively higher thrust second stage engine for North Korea’s space programme, given that North Korea wants to send heavier satellites into higher orbits. That second stage engine above could be a depiction of the second stage SLV engine statically tested earlier this year.
There’s never been an operationally deployed three-stage liquid fuelled ICBM, and a three stage liquid fuelled ICBM is not technically ideal. Some depict China’s DF-5 ICBM as a three stage liquid propelled missile, for instance Wikipedia does and the information provided there is almost certainly taking from the Federation of American Scientists, however the images below show the DF-5 to be a two stage missile.
Why would North Korea want a more powerful three stage liquid fuelled ICBM? I, again to speculate, suspect that North Korea wants an ICBM able to target all the lower 48 states with a greater throw-weight than the Hwasong-14 because it wants to target the US with higher yield two-stage thermonuclear warheads, that is hydrogen bombs. The DF-5 has throw-weight of approximately 3,000kg and the booster is powered by a cluster of four engines each of similar performance characteristics to the Pektusan, recall however that the KN-08 depicted in the poster has three stages.
Kim’s visit, in part, could well be a demonstration not so much of its missile aspirations as its warhead aspirations. Don’t forget that a missile is designed to deliver a payload, and it is the payload that matters.
It could well be possible that the Hwasong-13 is an aspirational road mobile solid fuelled ICBM, as solid fuelled ICBMs have three stages as that is the most technically optimal configuration. That would make sense. It is not clear from the poster whether the Hwasong-13 or KN-08 is liquid propelled or solid fuelled. The burden of the discussion here is focused on the liquid propelled side of things only because the KN-08 was to be a liquid propelled missile.
We should note that the Pukgoksong series of solid fuelled missiles are adapted from the Soviet R-27 (SS-N-6) SLBM. North Korea has, therefore, a history of using liquid fuelled missile airframes and modifying them for use as solid motor casings. Perhaps the same will apply to the Hwasong-13 (KN-08). If so, then the Hwasong-13 solid motor modification does not necessarily imply hydrogen bomb aspirations as road mobility and survivability could be the dominant concern.
Don’t forget that North Korea’s liquid fuelled long range missiles have the appearance, rather than the reality, of road mobility. These are missiles designed to be launched on the Chinese “shooting a firecracker outside the front door” firing mode.
It’s too early to call on the liquid versus solid question. The ballot hasn’t even closed, as we’re talking here about a poster. It could even be a bluff, for all we know.
Speaking of solid missile motors, the other big item coming out Kim’s photo-op was the poster image of a new missile, the two stage solid fuelled Pukguksong-3 intermediate range sea launched ballistic missile. That naturally has analysts speaking about a possible future solid fuelled road mobile ICBM. The Soviet SS-20 road mobile solid fuelled IRBM, that sparked the double-track controversy within NATO in the early 1980s, was a two stage IRBM and it formed the basis of the USSR/Russia’s road mobile solid fuelled ICBMs, the Topol (SS-25) and Topol-M (SS-27).
A key technical insight into advancing North Korean capabilities was provided during Kim’s visit, namely filament weaving of composite materials for large solid motor casings which leads to relatively lighter solid motor air frames. The North showed both a filament weaved motor case, and the machine tool for developing it.
The filament weaving of composite materials for large, high strength but low weight, solid motor casings was a key step, for example, in the Soviet SS-20, SS-25 and Russian SS-27 solid fuelled missile programmes. The image below depicts a solid motor casing showing the filament weaving and binding from Kim’s visit. The second from a Russian depiction of a solid motor case for the Topol-M (SS-27), and the third from Kim’s visit showing the outlet for the motor nozzle which can’t be seen on the first image.
This demonstrates the concerns North Korea’s strategic planners have regarding the survivability of its nuclear deterrent in any conflict with the United States. A true road mobile ICBM capability is more survivable than a liquid fuelled “shooting a firecracker outside the front door” capability. The Pukguksong-3 stands to a road mobile ICBM in the same way that the Hwasong-12 IRBM stands to the Hwasong-14 ICBM. One can see here survivability concerns too. The Hwasong-12 is designed for taking out US strategic assets in Guam, but it too would use a “shooting a fire cracker outside the front door” strategy for it needs to be fuelled prior to launch (which carries a visible logistical footprint so it’s not just a matter of relative promptness).
The Pukguksong-3 solid fuelled intermediate range sea launched ballistic missile would give North Korea a more survivable means of attack against Guam than the Hwasong-12, and furthermore the Pukguksong-3 would be pose more challenges for THAAD BMD.
One interesting aspect of the reports and commentary regarding the Pukguksong-3 and solid motor casing is the expression of widespread “concern” regarding North Korea’s display of advancing, and aspirational, capability. In this case road mobile solid fuelled missiles contribute to strategic stability. If the world is to live with a nuclear North Korea would not a more survivable North Korean nuclear deterrent be more stable, than a North Korea jittery about the survivability of its liquid fuelled nuclear missiles?
The expressions of concern seem to show that the concern is more about the self-deterrence of the United States rather than the increased capability for North Korea to launch a nuclear first strike against the US, that’s especially the case if one adopts the thesis that Pyongyang basically already has a boosted fission warhead compact enough for striking, at least, targets on the US west coast. If that assumption is correct then the analysis does not necessarily hold.
The more survivable and reliable North Korea’s strategic nuclear capabilities are the less credibility US extended deterrence in Northeast Asia has, and that’s why Kim Jong Un’s visit to the Chemical Materials Institute has sparked widespread concern.
There was also some interesting stuff on the RV front. There were some images and models of the nose cone of an RV, see two images below.
The KCNA press release contained comments about work on an ablative carbon composite material, which suggests that North Korea seeks (or has perhaps even) the ability to develop more pointed nose cones for its long range missile RVs. It’s not the first time that KCNA has spoken of this. For example, very similar remarks are contained in the KCNA press statement following the Hwasong-12 IRBM test. This is also a natural step for North Korea to make, that is moving from research and development on blunt body RVs to triconic and conic RVs. The image below (see far right of the poster near the white wall), taken from Kim’s visit, appears similar to the Hwasong-12 RV, and it also appears similar to the triconic RVX-1 RV that represented a transitional stage in the US RV programme which is shown immediately below it.
The KCNA press release contained comments about work on an ablative carbon composite material, which suggests that North Korea seeks (or has perhaps even) the ability to develop more pointed nose cones for its long range missile RVs. It’s not the first time that KCNA has spoken of this. For example, very similar remarks are contained in the KCNA press statement following the Hwasong-12 IRBM test. This is also a natural step for North Korea to make, that is moving from research and development on blunt body RVs to triconic and conic RVs. The image below, taken from Kim’s visit, appears similar to the Hwasong-12 RV, and it also appears similar to the triconic RVX-1 RV that represented a transitional stage in the US RV programme which is shown immediately below it.
There was a time when all this was the cutting edge of technology, and the peak of modernity.
Today that’s more apt to be quantum computation or biotechnology, but for North Korea the aura of modernity provided by all this serves to legitimise the regime as it served to legitimise the shift toward more technocratic political and social forms for us back in the day.
Analysts have focused on possible timelines regarding how quickly North Korea can develop a solid fuelled sea launched IRBM, road mobile ICBM, and triconic and conic ablative RVs. I subscribe increasingly to the view that we have underestimated North Korea’s scientific and engineering capabilities.
We should ask; why have we done this?
I think we have done this because nuclear weapons and ballistic missiles have an aura of “hardness” about them. Nuclear physics and rocket science were once seen as the hardest of the hard sciences, but they aren’t anymore certainly not nuclear physics and rocket science circa 1960s and 1970s.
One important point, not unrelated to the two just made above, is that North Korea in a sense is reinventing the wheel which is relatively easier than inventing the wheel. North Korea has a broad idea of the advances required, and pitfalls and blind alleys to be avoided. There is, naturally, the issue of tacit knowledge but these matters are no longer at the frontier of science which has moved on.
The peak of 1950s to 1970s Western science and technology is seemingly something even an isolated developing state can crack, so long as it has sufficient determination and cause to do so. This is a nuclear proliferation lesson we should remember.
Update. Come to think of it, perhaps the most interesting aspect of Kim’s visit to the Chemical Material Institute is the one under our noses. The Hwasong-13, the Pukguksong-3, the carbon composite material and the RV all is something akin to concurrency in action. When North Korea statically tested the Pektusan engine, core of the Hwasong-14, a KCNA statement cited Kim as saying the key to its development was the abandonment of conservatism, dogmatism and formalism in Pyongyang’s missile programme. That, not the Soviet RD-250 engine, is the key to North Korea’s success.