On North Korea’s Indigenous Production of UDMH: A Small Spat Reveals Much

An odd little article appeared recently in The New York Times on UDMH or unsymmetrical dimethal hydrazine and North Korea’s missile programme. The article pretty much is of a certain all too common genre. It’s main thrust, pun intended, is to suggest that North Korean technical advances have been facilitated through espionage and assistance from roguish external elements.

That is to say, the article fits into a broader body of analysis that supposes that the critical advances made over recent times by North Korea have not been, or largely have not been, indigenous.

The article itself is intriguing for it kind of reminds me of Godel. That is, it actually opens with a self refutation so we end up having a type of liar’s paradox at work here. Clearly this article could do with some application of the law of the excluded middle. The NYT article appears to be decidedly undecidable. Let us put this little irony aside and deal with the specifics.

I should stress however, that the most important feature of the UDMH debate has been entirely over looked by analysts. I will return to this point at the end.

The whole UDMH angle, as this quite superb detective work by analysts at the Centre for Nonproliferation Studies states, was more than a little unexpected. It came out of left field, as it were. That said, I think the UDMH spat is an excellent means to get into some nitty gritty on the technical debate on North Korea’s strategic nuclear capabilities because it demonstrates, in microcosm as it were, the main weakness of the non indigenous argument.

UDMH, a storable hypergolic propellant, is actually quite an old missile/rocket fuel. For example, right at the beginning of the Soviet ICBM programme it was central to the propellant debate that pitted Korolev and Glushko on opposing sides. Glushko wanted to use UDMH for the R-7 Semyorka, the world’s first ICBM and of course the historical foundation of the Soyuz space launch vehicle.

The New York Times states that the Russian are “leery of the propellant,” which is only partly true. Following the R-7 the Soviets used UDMH on their silo based liquid propelled ICBMs, and most likely it will be used as a propellant for the Sarmat ICBM the upcoming successor to the SS-19 liquid propelled ICBM. Furthermore the 1960 Nedelin disaster was caused by a short circuit in the second stage, not UDMH per se (although UDMH accounts much for the force of the explosion its mere presence was not causal as suggested by the New York Times).

The United States also used UDMH for the Titan II ICBM and Titan II derived space launch vehicles. In this case the fuel propellant consisted of 50% hydrazine and 50% UDMH a combination known as Aerozine-50. The latter provides a little more specific impulse than UDMH alone, all things being equal. Hydrazine in the early days of liquid propelled engines was seen as a promising fuel, however it was too explosive for regenerative cooling.

Michael Elleman, in his ISIS paper claiming that the Soviet era RD-250 engine forms the basis of the Hwasong-12 and Hwasong-14 core engine, states that China does not produce liquid propelled engines that are similar to the HS-12 and HS-14 core engine (he uses the expression “uses same storable propellants and thrust” as the North Korean engine) which isn’t true as the first stage of the DF-5 ICBM uses the YF20-A engine which produces a comparable thrust to the RD-250 (824 kN to 880kN) and also employs UDMH propellant.

Notice that the New York Times article lists China as a possible source of UDMH fuel. These are small logical niceties but it shows how the espionage position can be inconsistent.

Now the chemical process, as the CNS analysis quite rightly points out, for producing UDMH has been known for quite some time. That is, UDMH is produced using a variation of the Olin -Raschig process which substitutes dimethylamine for ammonia in the Raschig process. To be sure UDMH is explosive and it is toxic making those who use it “leery.” That toxicity is the key issue in its large scale production, especially the toxic water by product.

The toxicity of UDMH is a problem at the tacit dimension. The underlying theory of chemical separation is well known, and has been for a very long time. The UDMH story promoted by The New York Times, and those who adopt it, neglects the theoretical dimension assuming either that North Korea does not have access to it or most likely could not figure it out, so therefore assistance was surely provided. North Korea has ready access to the underlying theoretical details, the toxic tacit dimension for large scale production was the key problem, and that’s a matter of time and experimentation. The problem of UDMH production is phenomenological not theoretical.

In many ways that point generalises. The US and the Soviet Union had to invent the Ulam-Teller device. To a certain extent North Korea did not have to. The US and the Soviet Union had to develop blunt body theory when developing their first ICBM Reentry Vehicles. North Korea did not have to. North Korea has access to theory that was developed during the first nuclear age.

The sceptical position with regard to North Korea’s capabilities just about completely ignores the observation that North Korea has access to a large body of theory previously developed, and the UDMH story demonstrates this beautifully. The North Korean economy has been characterised by a highly perceptive Japanese economist as that of a “poor advanced country.” In many respects, to me at least, North Korea comes across as a type of positivist paradise (the distorted version not the real version). Technical and scientific study is highly prized and emphasised in North Korea, the humanities and social sciences less so. Tacit knowledge is a problem, yes, but with careful, detailed, and resourced work it can be overcome.

The former world chess champion, Bobby Fischer, explained that at the age of 14, after fanatically playing and studying the game, he “just got good.” There’s no established single theory of chess, but one could argue that Fischer acquired a deep, tacit, understanding of the game. North Korea has cracked the tacit dimension to much of the strategic nuclear enterprise and they have done so because, as is the tacit dimension’s want, North Korea’s scientists and engineers “just got good.”

The sooner we realise that the better.

Okay, so what’s the big point that analysis and commentary has missed regarding the UDMH debate?

Consider these passages from the Times’ article

A memo designated “secret” and signed in October 2008 by Condoleezza Rice, then the secretary of state, warned allies that the North had obtained an engine powered by UDMH that “represents a substantial advance in North Korea’s liquid propellant technology,” adding that it “allows North Korea to build even longer-range missiles.”


When Hillary Clinton succeeded Ms. Rice in 2009, she issued a similar warning. “North Korea’s next goal may be to develop a mobile ICBM that would be capable of threatening targets around the world,” she wrote to member states in the missile control group.

North Korean work on UDMH was known, at least from 2008 onward, to provide a foundation underpinning future development of a long range missile programme, and yet the United States pretty much refused to pursue diplomatic initiatives that may have headed that prospect off at the pass. Instead, the US sought to tighten controls in the context of the Missile Technology Control Regime and that, obviously, was partly based on a dismissive view regarding what North Korea could do indigenously.

The most important aspect of the UDMH story, which nobody has even noticed, is that it demonstrates the sheer folly of hitherto prevailing North Korean policy and the once existing opportunities now missed.