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A New ICBM for North Korea?

By
22 December 2015


By John Schilling, Jeffrey Lewis and David Schmerler

Executive Summary

The intercontinental ballistic missile (ICBM) displayed by North Korea during the military parade in October appears quite different from the versions seen in 2012 and 2013, but a close examination reveals as many similarities as differences. The missile has been shortened and simplified, with two stages instead of three and a blunt warhead replacing the narrow triconic design. The underlying technology is mostly the same—a blend of North Korean engineering and Cold War leftovers from the Soviet Union—but the structural design has been substantially improved. There is reason to suspect that the new structural technology was illicitly obtained from Ukrainian sources. The overall effect is that the missile’s performance is largely unchanged (and remains quite marginal for an ICBM), but the potential reliability has been substantially improved. (However, such a substantial design change late in the missile’s development will likely delay its entry into service until 2020 or beyond.

Examination of external features such as fuel ports and separation motors indicates that the lower stages use the same engines as the 2012/2013 model. These are most likely a cluster of Scud-type engines for the first stage and a second stage based on the Soviet R-27 submarine-launched ballistic missile (SLBM). There is no evidence to suggest that the most recent model incorporates new engines such as those of the R-29 SLBM. However, the propellant tanks for both stages have been lengthened substantially, and the third stage has been removed.

The missile’s structure, of which the propellant tanks are an integral part, has been substantially improved. The new model does not show the extensive riveting seen on earlier models and on debris from the 2012 Unha-3 launch. This apparent alteration suggests the addition of a machined isogrid structure common on modern missiles, reducing the weight and extending the range of the KN-08. There is evidence that North Korea is seeking expertise in this area from previously unknown sources. In June 2012, Ukraine reportedly sentenced two North Korean diplomats who had attempted to photograph secret documents from the Yuzhnoue Design Bureau relating to the construction of improved fuel tanks.[1]

Finally, the triconic warhead of 2012/2013 has been replaced by a short, blunt reentry vehicle. This design is easier to develop and is more likely to survive reentry, at the cost of being less accurate and more vulnerable to missile defenses. It would also allow for a lighter warhead package, perhaps as little as 400 kg.

With a light warhead, the new KN-08 would have a range of roughly 9,000 km, enough to cover the US west coast. This is roughly the performance expected from the 2012/2013 model, but that design was a complex three-stage system that was unlikely to function reliably in wartime. The new design is simpler and more reliable, and thus a more credible threat. But with a major redesign four years into the development process and no flight testing so far, our estimate for initial operational capability slips to 2020 or beyond. While North Korea appears to be making progress towards a road-mobile ICBM, progress has been slower than we expected—a threat postponed, but not prevented.

Figure 1. The KN-08 missile in 2013 (top) and 2015 (bottom).

Photos: KCNA.

Photos: KCNA.

Introduction

A New Reentry Vehicle

Changes to the Upper Staging  

A New First Stage

No More Rivets

What’s “Under the Hood”

What’s the Bottom Line?

Download the full report here.

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[1] “N. Koreans convicted of trying to steal rocket technology from Ukraine,” Yonhap News, June 9, 2012, http://english.yonhapnews.co.kr/national/2012/06/09/91/0301000000AEN20120609000700320F.HTML.

Reader Feedback

2 Responses to “A New ICBM for North Korea?”

  1. XuTianran says:

    I was also in Pyongyang on Oct 10 and witnessed the parade. According to photos i took, Hwasong-13 is written both on the red plate and black weapon-designation plate on the TEL. Why it is also called Hwasong-14, and by whom?

    the “oxidizer inlet” and “exhaust port” on the small conical section with four thrusters would suggest the purpose of the section is more than RV separation. For acceleration of the RV, small solid rockets are enough. It is also doubtful that NK engineers designed this small conical section only for the purpose of RV separation: it would be too complicated and there are other, simple ways to realize a smooth separation, especially when retro rockets are used on the second stage for deceleration. My guess is that the small section is a very small third stage or more likely, a post boost vehicle. Of course NK tried some rather complicated separation methods before–the 1st stage of Unha-3 used dual-plane separation. But it used small solid rockets on the interstage ring to do the job, no “oxidizer inlet and exhaust ports” on it.

    And on photos i took there are lot of rivets on the interstage ring between 1st and 2nd stage and on the interstage ring between 2nd stage and the(possible)PBV.

    My analysis was published (and a follow-up piece going to be published) on the Chinese language magazine Aerospace Knowledge. I wonder if i can send 38north editors my article and photos concerning this topic?

  2. Mark Sommer says:

    Good information. Conceivably a two stage rocket would be more fail safe than a three stage one thus posing more of a threat. There were reports of a failed SLBM recently though not independently verified to my knowledge. it was thought that a satellite launch was going to take place on the 100th Anniversary of Kim il Sung’s birthday but it failed to materialize possibly due to strong international opposition and concern. Additionally no new underground testing has taken place for a few years now, and with the exception of the land mine incident that maimed the two S Korean soldiers earlier this year. things have been relatively calm. The North has pressed for a Peace treaty with the US but has been rebuffed due to their nuclear program. Obtaining a test ban from the North may be a good first step toward nonproliferation if not outright de-nuclearization, although this seems increasingly unlikely due to the North’s security concerns and ultimately its survival.

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Credit for photo of young North Korean girl: T.M. All rights reserved, used with permission.