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The Pukguksong-2: A Higher Degree of Mobility, Survivability and Responsiveness

By
13 February 2017


Sources in the United States, South Korea and Japan reported that North Korea launched a ballistic missile over the weekend. North Korea has been hinting at an intercontinental ballistic missile test since the beginning of the year, but this was no ICBM. Reports indicate that this missile reached a height of 550 kilometers before impacting in the East Sea, 500 kilometers east of the DPRK. The US Strategic Command describes this as a medium or intermediate-range ballistic missile. South Korea’s Yonhap News Agency reported that Seoul’s Joint Chiefs of Staff initially assessed the missile as a Nodong medium-range missile, then changed their mind and said it was a “modified intermediate-range Musudan ballistic missile possibly equipped with a solid fuel engine.”  Finally, North Korea’s Rodong Sinmun provided pictures of what it is calling the “Pukguksong-2, solid-fuel missile.” The pictures show something very similar to the KN-11 solid-fuel submarine-launched missile successfully tested last August, which North Korea calls the Pukguksong-1.

A photo of North Korea's Pukguksong-2 pictured during a test on February 12, 2017 (Photo: KCNA).

The Pukguksong-2 pictured during a test on February 12, 2017 (Photo: KCNA).

We considered other alternate interpretations of this test, such as a failed or partial ICBM test in which only the first stage was functional, but the trajectory is not a good match for the first stage of any of North Korea’s known ICBM projects. With a much lower terminal velocity than an ICBM, it would not be terribly useful for testing ICBM-class reentry vehicles or other technologies. And while the launch site, a military airbase near Kusong, has previously been used for Musudan testing, the trajectory of this test was not a good match for the Musudan, either. The only plausible candidates for this trajectory are the proven Nodong medium-range ballistic missile, or the KN-11, and North Korea is showing us a land-based KN-11.

Aside from the assessment by the JCS, this missile has little in common with the Nodong or the Musudan. It lacks the performance of the Musudan, though if launched on a more efficient trajectory it could reach a range of at least 1200 km rather than the 500 km just demonstrated – enough to reach targets in South Korea or parts of Japan. What this missile brings to the table is a much higher degree of mobility, survivability and responsiveness than the Nodong. The Pukguksong-2 was tested from a cold-launch canister system carried on a tracked transporter-erector-launcher (TEL) vehicle, which would provide substantially greater cross-country mobility than the Nodong’s wheeled TEL. The solid-fuel missile is more robust, and as it does not need tanker trucks to carry propellant its logistical footprint is smaller. And as it does not need to be fueled prior to launch, it can launch on perhaps five minutes’ notice compared to the thirty to sixty minutes required for a Nodong. All of these factors would make it much harder to find and preemptively destroy the Pukguksong-2.

It takes more than a single test to ready a missile for operational service. And this test likely had a political dimension that may have affected the timing – it is almost certainly not a coincidence that North Korea launched a missile towards Japan, with the range to reach Japan but on a trajectory that deliberately dropped it into the ocean instead, on the day Japan’s prime minister was meeting the new US president in Florida. North Korea’s engineers presumably learned a great deal from this test, which appears to have been basically successful. We do not know how much more they need to learn to be confident that the new missile will function reliably in combat, and will look to the pace of future testing to gauge progress with this new system.

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21 Responses to “The Pukguksong-2: A Higher Degree of Mobility, Survivability and Responsiveness”

  1. Kyle says:

    I have seen some reports that the Polaris-1, and thus Polaris-2, could possibly be modeled off of China’s JL-1 SLBM. That being said, is there any aspects of this test that indicate any assistance from China to North Korea for the development of this missile? Or are there indications this was a North Korean in-house project?

  2. John Schilling says:

    Jay: This family of missiles uses a “cold launch” technique where a relatively low temperature propellant gas is used to eject the missile from the canister, and the missile’s own engine ignites a few seconds later. Hence the pause before the really spectacular fireworks. This minimizes the damage to the launch platform, particularly important for submarine-launched missiles but desirable even for land launch – we believe the North Koreans have destroyed some expensive TELs through too-vigorous “hot” launches.

  3. nyolci says:

    Jay V, the pause is due to the cold launch technology, and quite normal. Check out, say, a Topol-M launch, or an MX (Peacekeeper).

  4. Morris Jones says:

    John, good to see you are in better health. Thanks for the reply. I can accept your estimate for “five minutes” based on your suggestions, but it’s certainly a short interval. This is certainly a matter of concern to the outside world.

  5. Jay V says:

    I noticed that the missile seems to pause after exiting the launch tube and then accelerates after the main engine fires. I assume this is not unique to the Pukguksong-2. But what is going on there? Does that have something to do with the fact that it is a solid-fuel engine? I am curious about this aspect of the launch and technology.

  6. John Schilling says:

    A few late responses; I’ve unfortunately been sick the past few days.

    Video shows the new TEL operating independently from a paved surface with only a pair of rear jackstands for additional support, so five minutes to park, erect and launch is a reasonable estimate for a prepared and surveyed site with a preplanned fire mission. That is likely to be the preferred operating mode, but if things go badly enough for the North Koreans that they have to park at some random spot on a dirt road to launch it will likely take quite a bit longer.

    An additional complication would be warhead mating. We suspect, but do not positively know, that North Korea stores missiles and warheads separately in peacetime for security purposes. When and where they would attach the warheads is an interesting question, and a constraint on their operations.

    I don’t think it is plausible that this is simply a land-based test of the KN-11 SLBM. The North Korean navy has its own missile test facilities at Sinpo, including land and barge launchers to avoid risking the submarine. In the unlikely event that they felt the need to use an Army facility, I can’t see them building a unique new TEL for the job.

    We have been expecting a solid-fuel land-based MRBM or IRBM since we first saw evidence of North Korean large solid motor development; they have the same clear reasons for making that change that drove their former partners Iran and Pakistan to develop the Sejjil and Shaheen, respectively. It wasn’t clear that they would use the same missile as the navy, but looks that way now.

    Regarding hints that the missile may have improved guidance and/or evasion capability, there are features on the reentry vehicle that might be divert thrusters for post-boost maneuvering, but we can’t tell whether such a capability was demonstrated during this test. That’s a very tricky thing to get right, and I suspect the Pukguksong-2 is going to be operating in a purely ballistic mode for some years to come.

  7. FrankP says:

    Mr. Heyn, now is exactly the wrong time for the South to withdraw participation and collaboration with the US. To do so would be to submit to China’s demand that the South cease efforts to develop and or deploy an anti-missile defense system, provided by the US or otherwise. China is preparing for a multi-front war, and pushing any and all opposition as far from the Chinese mainland as possible only emboldens and facilitates their objectives.

  8. Matt Brown says:

    It does not seem reasonable that this missile would simply be a part of their SLBM testing rather than a new missile in it’s own right. There are significant hurdles to overcome to develop a TEL and the ability to launch on the move. If this was simply a test to work out the kinks in the kn-11 they would have launched it out of a stationary silo. NK may do goofy things but developing the TEL and launch protocol is not cheap.

  9. Nick says:

    the other great achievement demonstrated: use of tank chassis.
    they now use modernized tank test range for dual porposes.
    practical approach.

  10. J_kies says:

    Mr “Hayden” propulsion is not analyzed in the manner you suggest and based on the video (with editing) posted on Youtube, I think the missile performance wasn’t entirely as planned and the celebrations are presumptuous.
    Note https://www.youtube.com/watch?v=ZslOkxqr35Y

  11. Steven M Hayden says:

    Compare the rocket exhaust plume of US minuteman to Pukguksong-2.
    Both exhaust plumes are white. But the Pukguksong-2 exhaust plume is smoother suggesting smoother better energy release and higher efficiency and smaller particle size of solid fuel.

    https://en.wikipedia.org/wiki/LGM-30_Minuteman

  12. Steven M Hayden says:

    The pictures on Rodong are significant for shared joy and celebration between Kim Jong Un and the workers. It is a huge achievement for DPRK. The DPRK is merely moving their defensive technology forward. The DPRK even accommodated the trajectory to a less threatening path. Its entirely possible the rocket was over weighted or even only partly fueled to reduce trajectory. How many stages was it and was the payload recovered and weighed.

  13. Steve Hildreth says:

    I think the most plausible explanation is as J_kies described. The DPRK seems to be working through some of the kinks in their developing an SLBM capability.

  14. Hal says:

    Single-cast solid stages that big move on rolling stock or on really obvious road transport before vehicle integration with the erector-launcher. We have to know by know where they actually pour these stages – which is good trivia to know for what happens later.

  15. Kostadinov says:

    “The feature of the improved warhead to evade interception was tested”(KCNA)

  16. Nick says:

    is this the first time we clearly see a LAD separation phase?
    that’s a little something!

  17. T Webb says:

    Thank you for the excellent analysis.

    The DPRK said: “The test-fire […] reconfirmed the guidance and control features of ballistic missile during its active flight […].”

    What guidance and control capabilities do you suppose the DPRK might have or seek to acquire for such missiles? And if the DPRK can guide and control missiles during active flight, does that carry any implications for the ability of THAAD to intercept, given that THAAD appears to rely on trajectories calculated from the X-ban radar’s monitoring of the initial phase of flight only?

    Thank you.

  18. Steven M Hayden says:

    Necessity is the mother of invention. DPRK believes sincerely that these extraordinary efforts are necessary.

  19. Morris Jones says:

    This article suggests possible launches with five minutes notice. I think some more explanations of the overall launch preparations sequence is appropriate. The transporter has to be parked and secured. The missile must be erected. Then additional steps must be taken. I do not believe all of this could be done in just five minutes, and I suspect that the author is not trying to imply this. Let’s see some more exploration of this topic. Presumably, the article implies that the missile is already erect before this “five minutes” sequence starts.

    Watching the video of the missile erection is interesting. We don’t see continuous, unedited footage of the missile being erected. But we can make some estimates of how long this would take, based on the fairly consistent rate of the process.

    Further comments from the author (and others) please!

  20. Herman Heyn says:

    Another yearly, joint U.S.-South Korea military exercise is scheduled for next month (March ’17). With two such irascible, thin-skinned leaders (Trump and Kim Jomg-un) in charge, the slightest accidental incident could lead to a dangerous military exchange, perhaps with South Korea being the target of opportunity. I urge all readers of this site to contact the ROK embassy in DC (2450 Mass. Avenue,20008) and to urge Ambassador Ahn Ho-Young to advise Seoul to withdraw from its particiupation in the pending exercises.

  21. J_kies says:

    Dr Schilling; perhaps the DPRK is giving you the answer directly. The US SLBM development uniformly began each new increment with land-based launches before transitioning the missile to tube launches. I suggest this might be their analog to the Polaris A-2 updating the A-1. No significant advantage accrues to land-based mobile missiles with cold launch so they might be just development testing without the sub at risk.

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