Hello out there! Since Geoffrey Forden stopped blogging, ArmsControlWonk has been a little bit light in the ‘rocket science’ department – so Jeffrey asked me to fill that gap (frequent readers of this blog’s comment section may already have stumbled over my name here and there). Well, i’ll do what i can to round ACW out a little bit and thus make it even more enjoyable than it already is!
For my debut, i’ve decided to share some of my thoughts on the north korean ‘Mirim’-device (which is also known as ‘Musudan’ or ‘Nodong-B’). First of all, let’s understand that the ‘missiles’ shown in October 2010 almost certainly are non-functional mock-ups, as is common practice in case of military parades. Not only would it be a bad idea to put the top-ranking politicians attending that parade potentially at risk by driving by live ammunition, what is more, this would also expose a highly valuable asset (the missile itself) to unneccessary mechanical stress and danger of accident. A blank is more than good enough for this purpose, and, let’s be honest, the overwhelming majority of observers wouldn’t notice the difference anyway (think along the lines of the classical stage prop in movies).
Additionally, no flight tests of this missile have been reported up to date, so we’ll have to assume that that system hasn’t even reached initial operative capability – more or less a mere paper project, at least up to now.
Next, i couldn’t help but notice that there is no provision for any form of sealed canister for that missile on the TEL (which itself is rather overdimensioned for that payload). To me, that is a tell-tale sign of this missile likely not using NTO as an oxidiser – and thus, being a bad candidate for an R-27/SS-N-6/Serb engine block aka a stretched R-27. Why? Well, because of the chemical/physical properties of dinitrogen tetroxide and typical military requirements.
NATO ground equipment usually is certified to a temperature range of -30°C up to +50°C for good reasons, the warsaw pact armies even insisted in temperature-resilience down to -40°C (siberian winter nights seem to be somewhat colder). And if this is inevitable for military applications in moderate climate zones like middle europe, i see no reason why this should be any different for the north korean army. Dinitrogen tetroxide, on the other hand, freezes at -11 to -10°C, which will render an unprotected missile inoperable, this should be self-evident. No big deal if that missile is in a thermally conditioned environment, like in a silo, or inside of a submarine, or a heated canister, but out in the open that means loss of reliable around-the-clock operational capability, particularly during winter season. I’d say that that would be rather inacceptable from a military point of view, particularly if all earlier systems (Scud, NoDong etc.) don’t share this unfavorable characteristic.
Another benefit of a canister would be that that would mimic the R-27′s launching mode (hot-launched from a flooded submarine tube), yet, the ‘Mirim’-device instead closely follows the Scud/NoDong-line with a launching stool with integrated turntable and thrust deflector, which clearly points at a Scud-like guidance system (and general launch preperations), too, not an R-27-like, with the consequence of less accuracy and slower reaction time due to more time-consuming preparations. The ending of the cable duct at a different place than on the R-27 just adds to the impression that there is no original R-27-guidance system involved.
Not only that, the little two-chamber steering engine of the R-27 may be too weak to sufficiently deal with the requirements of a larger, heavier missile, so that may have to be replaced not only because of a change of propellants, too, probably also with a less-efficient solution available to the North Koreans like the ubiquitous jet vanes. The lower acceleration due to ~3-4t additional weight at liftoff wouldn’t be relevant, on the other hand.
Last but not least, the R-27 was a rather maxed-out lightweight design – so simply adding length and weight will likely overstrain an existing missile body without supplementary structural reinforcements, and this will inevitably add inert dry weight and thus diminish the achievable maximum range.
So, the big question is:
Is the ‘Mirim’ really some sort of simply stretched ex-russian super-R-27/SS-N-6/Serb with the same engine and propellant combination (as apparently widely accepted) with all the quite inacceptable drawbacks, or will the North Koreans be forced to replace the propellants, the engine and the guidance/steering system with e.g. that of the NoDong and strengthen the missile body, measures which will spoil the overall performance down to approximately that of the already available NoDong-2 (~1500km range)? If the latter is the case – why bother at all with a larger, heavier and more expensive missile without better performance?
I for my part am beginning to ask myself if the DPRK’s latest show of force was perhaps only a cunning ruse along the lines of Field Marshal Grigory Potyomkin’s famous villages.
