DPRK Large Solid Rocket Motor Design Heritage

©By C. P. Vick, 2011/2016

Senior Technical & Space Policy Analyst

3-10-2011/ 12-15-2015/4-23/28/4-24/26/5-24/9-28-2016

Introduction:

Understanding the historical heritage of the DPRK solid propellant ballistic missile program is critical to understanding where they are as well as what direction in new developments can and are in the immediate future and soon afterwards through three Five Year Plans including the present 2016-2020 Five Year Plan. The accelerated development that started during the previous Five Year Plans 2006-2010, 2011-2015 has evolved very rapidly into an advanced strategic ballistic missile program that only indirect or direct foreign assistance could have permitted. It had been apparent for many years that the DPRK simply did not have the solid propellant motor technology industrial base for such developments during all the previous five year plans back into the 1980’s. The Solid propellant program did not exist as they were only utilizing storable liquid propellant ballistic missile until very recently.

Reading the DPRK’s, Five Year Plan suggest that it is aimed for perfection of those strategic ballistic missile technologies within the new 2016-2020 Five Year Plan to the extent possible but only time will see if this occurs within that Military State. Typically things with in the DPRK mature early in the beginning or middle or near the end of their five year plan and this year’s events have been no exception to that rule as expected with their accelerated effort.

The DPRK NK-X-15 SLBM

Previous DPRK Solid Motor Experience

The initial thinking was that the Russian Federation supplied SS-21, Scarab, 9M79, 9M79M Tochka class tactical ballistic missile KN-2 was potentially the root of the DPRK solid propellant strategic ballistic missile program. Upon close examination of the actual DPRK solid propellant hardware technology program showed no relationship to the Russian Federation missile system in all details ending that perception. The steering vanes arrangement and nozzle details show a considerable difference from the indicated system design approach but it does not mean that the DPRK did not study the KN-2 details in its technology exploitation processes. Indeed much of the presumption of technology transfer from the Russian Federation to the DPRK solid motor program simply does not have hardware foundation right down in the design details and design approach utilized though there are the expected similarities. How much of an industrial base for the KN-2 was provided by the Russian Federation for the missiles replenishment or was provided from the Iranian Russian industrial base educational exchange efforts remains uncertain. Iran did get considerable solid propellant motor technology assistance from illicitly provided Soviet era and post-Soviet era institutional activities that greatly accelerated their efforts that the DPRK probable benefited from.

Although the DPRK had in the past utilized an identifiable Chinese spherical class solid motor as the third stage of the Taep’o-dong-1/Unha-1 and another cylindrical larger class solid motor similar to the FG-28M2 class as the third stage of the Taep’o-dong-2/Unha-2 both seemed to have failed in their missions. This kind of repeated failure experience forced the DPRK to switch to a storable highly toxic liquid propellant third stage for the Unha-3 series that has been successful. So that initial experience with Chinese based solid propellant motors hardware was not very promising to the DPRK missile launch, space launch efforts in its earlier in experienced applications.

Certainly the Russian Federation supplied SS-21, Scarab, 9M79, 9M79M Tochka class tactical ballistic missile KN-2 effort experience had taught the DPRK some serious lessons to be applied to the new strategic rocketry technology acquisition effort with the added experience needed.

It suggest that the DPRK reexamined thoroughly its experience as applied to their desired strategy rocketry Five Year Planning efforts and subsequently sought successfully to seek those quid pro quo near abroad allies Chinese based hardware, technology and experience. This was through the more successful foreign program that was pliable to their “business needs” that have successfully utilized the Chinese hardware programs. In doing so they were getting what was required for their intended accelerated efforts regardless of how or what the multiple faceted approaches utilized entailed. It was almost certainly targeted for acquisition and industrial base production development from China to Pakistan and then to the DPRK during the previous two DPRK, Five Year Plans 2006-2010, for acquisition and 2011-2015 for R&DTE by the DPRK. That production industrial base is now centered on the Ryongsong Machine Building Complex of Hamhung with its separate small remotely located static test firing complex within the South Hamgyong Province of the DPRK. Utilizing a foreign country’s program to get that hardware and experience delivered to them is classic DPRK operands.

For proof of this we need go no further that the August 25, 2016 KCNA statement:

“The DPRK stated that it acquired these technologies in its recent announcement probably during the previous five year plan as an accelerated program for infrastructure development and program development start. … “ officials, scientists and technicians in the field of national (defense) science and munitions factories for havingperfectly acquired the technology of SLBM in a short span of time” has immense implication to the real story. I do not agree that they have copied the PRC JL-1 SLBM as the design details are different but the technology is similar.

NOTE: Pakistan acquired the similar Chinese based solid propellant technology program from the PRC China with its identical design features and then in turn it was apparently quickly acquired by the DPRK from either Pakistan which is circumstantially suspected or perhaps direct from China in a strategic geopolitical move for its Quid pro quo ally. This helped the DPRK’s solid motor development effort almost cutting out one full Five Year Plan in addition to it accelerated flight testing effort. Normally this kind of effort takes three full Five Year Plans unless foreign technology is acquired for the effort in a classic Soviet styled accelerated strategic program much like was carried out for the R-7 booster.

In order to understand how far back this multi-faceted program goes in the previous two Five Year Plans for its origin it is need to consider the accelerated technology transfer process and its impact on the normal multiple FYP process. When did they get the technology transfer and set up the programs as well as set up the facilities to build and modify for the program elements, the testing and production modification from a converted factory adding test and mods to round out the plans of the infrastructure as well as decide of what to develop and the requirements to develop what we are now seeing etc.

Previously the DPRK had displayed a perfected 1.10 meter diameter large solid motor but this new 1.4 meter diameter solid motor has huge strategic implications for not merely Sea Based but also Land Based strategic ballistic missiles. The 1.10 meter diameter solid motor may be a part of the rail mobile missile system in the office within this 2016-2020 Five Year Plan.

The country among those previously utilized by the DPRK is the Chinese to Pakistan route and DPRK to Pakistan technology transfer trade operations followed by seeking to develop the Pakistan to DPRK business. This was via the Chinese space applicable solid propellant motor technology transfer that both Pakistan and the DPRK could utilize to their own desires. Almost certainly that industrial base came with the deal. IE the plausible deniability route to the DPRK through foreign near abroad allied sourcing 3 rd. party business deal. Pakistan has been exploring developing its own space application booster so this was the natural choice to exploit. Where has Pakistan recently gotten the funding to open a new nuclear enrichment facility and whom is to benefit from it besides Pakistan?

Deception is the game always by the DPRK and PRC way of life

It cannot be ignored the DPRK, Iranian financed technology transfer agreements as well as the and Pakistani and PRC technology transfer operations and the PRC real policies that are not friendly to the West that they are now aggressively pursuing in the South Pacific as more of the near abroad allies buffer zone effort. Nobody can ignore the Iranian DPRK technology transfer agreements and its financing of DPRK missile and nuclear weapons development for the two of them otherwise it would not be happening as it is in the DPRK. If the DPRK get it the Iranians will get it especially if they finance it. Iran is known to be working on a 5.000 kilometer range solid propellant LRICBM and so the DPRK may benefit equally. Ultimately the DPRK wants a solid propellant ICBM for itself and this program is designed to make that a reality as both a space booster and SLBM program effort in cooperation with others previously noted.

However what does the solid propellant motor hardware technology tell us about that effort and its sources?

Those DPRK solid motors have many of the design characteristic of solid propellant ballistic missile technology of the PRC China that then went from China to Pakistan and Iran ultimately coming to the North Koreans. The most direct technology transfers came both from China and Pakistan with additions from Iran via their joint Science and Technology Transfer Cooperation Agreement. Basically the solid motor hardware and technology transfer whether from China or Pakistan or both were for the basic solid motors not their added application derivation developed by the various nations own engineers and technicians. The copying of the solid motor hardware technology is as complete down to details as to be unmistakable in the assessments of the basic solid motor real heritage.

Solid Motor Foreign Technology Transfer to the DPRK Implicated

The DPRK was able to very rapidly accelerate its identifiable Chinese/Pakistani/Iranian based classes of solid motors program from that successful multifaceted technology transfer endeavor. It only required technology duplication reverse engineering and materials duplication, processes or viable substitutions for filament wound casings like steel material changes and change out from vacuum thrust nozzles for sea level nozzles or altitude nozzles as required for the specific applications all readily available.Increasing the diameter from 1.4 meter is also a viable modification probably conducted by the DPRK.Each solid motor would have its solid propellant machined before the application nozzle was installed for the required performance sought. Examples are the Pakistani Shaheen-1, Chinese M-9, DF-11, DF-11A, 0.88 meter diameter solid motors, DF-15, DF-15A and SpaB-100, L-Spab-100 utilizing a 1-1.10 meter diameter solid motor and the Shaheen-II, Chinese M-18, utilizing 1.4 meter diameter solid motor based on Chinese provided technology assistance as well as the Chinese based SpaB-140 series and L-SpaB-140A, 1.4 meter diameter series of space solid motors and the Iranian 1.25 meter diameter solid motors utilized on the two stage Sejjil and its vane steering housing designs details. Certainly some technology education from the Russian could be implicated through the Iranian solid motor efforts. Iran’s lack of success with larger than 1.25 meter diameter solid motors is a natural for paying for and seeking foreign assistance if not full development with the full technology transfer built into the agreement for their own production.

Previously the DPRK had displayed a perfected 1-1.10 meter diameter sea level or altitude upper stage or both solid motor indicating a new land or sea based shorter range two stage ballistic missile systems in development.However this new SLBM, KN-X-15 with its 1.4 meter diameter solid motor has huge strategic implications for not merely sea based but also land based strategic ballistic missiles developments presently in progress but with more in the offing to come through the present and following two Five Year Plans. That expectation is believed to be in development progress today.

KN-X-15 IRBM Solid Propellant Ballistic Missile

Close study of the launch imagery of the KN-X-15?, has revealed it is a two stage, SLBM with a 2,200 kilometer range performance carrying a known 600-650 kilogram standardized warhead. The DPRK, two stage solid propellant motors SLBM, KN-X-15 still in R&DTE development but subsequent derivation designs are in the near future R&DTE expectations. Its height is about 9.525 meters and has a diameter of 1.4 meters matching the liquid propellant KN-11 SLBM design diameter and height of its two silo launch tubes installed on the Sinpo-class submarine. The 1.4 meter diameter solid motors appear to in part be housed inside a basic 1.4 meter diameter two stage airframe design.

The DPRK NK-X-15 SLBM

Those four primaries *Space Program Based Chinese Solid Motors are as follows:

China Hexi Chemical & Mechanical Company to Pakistan then on to the DPRK

Revelations of Other Potential DPRK Solid Propellant Ballistic Missile in Development

Perhaps a series of multi-staged much longer range strategic ballistic missile KN-X-?+, based on the first two stages of the KN-X-15 and the new medium range solid propellant ballistic missile stage or stages designs. What is so revealing about this DPRK solid motor ballistic missile developments is its predominate sole source reliance on the China based commercially available space program solid motors design for the technology transfer and modification there of developed by the DPRK for its desired applications. There still is no sign of Pakistan Shaheen-1 and Shaheen-II solid motors technology transfer in the revealed developments displayed or understood as being in the offing. This however, does not preclude that having not taken place from Pakistan. Rather it appears that a missile with a capacity between the Pakistan Shaheen-1 and Shaheen-II is in fact being developed by the DPRK as a land or sea based system .

The known Iranian, Ashura and Pakistani, Shaheen ballistic missile heritage systems probable contribution to the joint Iranian & DPRK technology transfer agreements. The probability that Pakistani involvement remain circumstantially self-evident from what it acquired from the PRC China.

The solid propellant SLBM / ballistic missile heritage system

The DPRK Potential Solid Propellant Ballistic Missile In Development

Potential DPRK Solid Propellant Ballistic Missile in Development

NK-X-Concept-A – Know to be in development would have on the order of a potential range of 1,500-2,000 kilometer as a land or sea based ballistic missile system. >From what has been openly released by the DPRK besides the KN-X-15, IRBM missile flight tests there is a clear implication for a new 1-1.10 meter diameter one or more probable two stage sea based or land based tactical medium range solid propellant motors ballistic missile KN-X-(Concept A), is known to be in the immediate offing during this five year plan. They have already successfully static test fired the stages successfully. We have the images of the stage firing that Kim Jung-Un observed. Based on previous work on these solid motors the Chinese technology based first and second stage 1-1.10 diameter solid motors will have a first stage length of 5.410 meters while the second stage will be 2.489 to 3.30 meter in length.

NK-X-Concept D This growth potential development system would have a potential range performance on the order of 2,500-2,800 kilometers as a land based ballistic missile system. This design features a lengthened first stage from the KN-X-15 SLBM of 1.4-1.5 meter in diameter solid motor up from its 2.892 meter length to 5.250 meters. Its second stage utilizes a 1-1.10 meter diameter altitude configuration solid motor with a length of 2.478 to 3.30 meters. The likely hood that this design will be adopted for development as a sea based much less a land based system is questionable except for technology demonstration because it is an interim step leading to the advanced Concept–B newer long range SLBM.

NK-X-Concept-B This growth potential development system would have a potential range performance on the order of 2,800-3,000 kilometers as an advanced SLBM sea based ballistic missile system.

Concept-B is a highly improved version of the KN-X-15 featuring an advanced lengthened first stage of 5.250 meter as previously developed by China, while utilizing the same second stage of KN-X-15 with its 1.489 meter long solid motor. It would in reality require a much larger strategic ballistic missile submarine to be developed over this and the next DPRK, Five Year Plans. Facilities are in the advanced stage of being finished to produce larger SLBM submarines with greater regional range expectations.

NK-X-Concept-C This growth potential development system would have a potential range performance on the order of 3,200-4,400 kilometers as a very advanced SLBM sea based ballistic missile system. This concept utilized the maximum improvement over the KN-X-15 with a lengthened first stage from Concept-B while utilizing the KN-X-15 first stage with an altitude nozzle as its second stage. It would however require an even larger than presently in development strategic ballistic missile submarine to be developed over this and the next two DPRK, Five Year Plans.

NK-X-Concept-E This is a smaller 1.10 meter diameter solid motor applied to tactical MRBM-medium range ballistic missile equivalent to the existing DPRK No-dong-A1 with its 800-1,000 kilometer range would not require as long to set up and launched from a TEL serviced pre-survey launch site. It could be applied to land mobile and rail mobile missile TEL platforms. That is a future missile system in development now as predicted but will probably have a longer solid motor design similar to the Shaheen-1 of Pakistan although a two stage design also offers better potential performance characteristic if successfully developed.

NK-X-Concept-G/H This growth potential development system would have a potential range performance on the order of 5,000 kilometers LRICBM for Iran and the DPRK that has been in development for some time now. It may incorporate some of the Iranian Ashura three stage ballistic missile technology upgraded with the new DPRK proven technology. We must recognize the Iranian and Pakistani contributions to the DPRK solid motor program in the sense that Iran has developed the longer 1.4 meter diameter solid motors and Pakistan has adopted the PRC Chinese M-18 1.4 meter diameter solid motors to the Shaheen-II/Haft-6 first and second stages that in sea level and altitude vacuum thrust variations is inevitable wrapped up with the Technology agreement between Iran and the DPRK. Therefore the probability that the DPRK will introduce a lengthened first stage solid motor to its future now in development strategic ballistic missiles (G), (H) class as displayed below will in fact match the Iranian “Ashura” and Pakistan “Shaheen-2” solid motor technology. A lengthened first stage for the (G) design would greatly improve its performance assuring its introduction. In reality the Iranian Ashura second and third stages are Chinese solid motors in the DPRK knowledge base. (H) Actually represents the technological decisions that the DPRK design team faced to evolve to the (G) and (J) design R&DTE process.

NK-X-Concept-J This is an evolution of the technology transfer from both Iran and Pakistan to the DPRK for both the 5,000 kilometer and ultimate full range ICBM projects. (H) Actually represents the technological decisions that the DPRK design team faced to evolve to the (G) and (J) design via the R&DTE process. The known Iranian, Ashura and Pakistani, Shaheen ballistic missile heritage systems probable contribution to the joint Iranian & DPRK technology transfer agreements. The probability that Pakistani involvement remain circumstantially self-evident from what it acquired from the PRC China.

These last two options “B” & “C” would have to be explored in greater detail for its possibilities beyond this limited study. Although the depth of the new submarine silo’s up to three suggested must be closely monitored for development well beyond the present limited Gulf-II class submarine technology demonstration systems platform.

The Russian Federation supplied SS-21, Scarab, 9M79, 9M79M Tochka class tactical ballistic missile KN-2 exhibits a steering vanes and nozzle arrangement details showing considerable difference from the indicated system design approach utilized in this test article.

It more closely resembles the known Iranian, Sejjil and Chinese DF-15 design details steering vanes details but it does not mean that the DPRK did not study the KN-2 details in its technology exploitation processes.

It still strikes this analyst that the Chinese commercially available space program based solid motors is the basis to the rapid DPRK solid motor developments. Just one example of each of the SpaB-100, 1.0 – 1.10 meter diameter and SpaB-140A 1.4 meter diameter solid motors hardware would have sufficed to allow the DPRK to accomplish what it has with all of its growth potential applications for space or strategic application. In spite of the issues militating against this being a direct Chinese technology transfer to the DPRK but instead via Pakistani technology transfer from China a known operando utilized route it is obvious that the DPRK did acquire the information and hardware technology to accomplish what is plainly obvious.

These missile and nuclear weapons programs are highly depend on direct technology transfer and financing from third world nations and China the PRC. The focus on Iran and Pakistan is exceptionally obvious and China is not innocent here either. The PRC is continuing its heavy handed near abroad ally’s support and buffer zone projection operations.  The PRC is exceptionally suspicious where the solid motor technology transfer is concerned for DPRK strategy ballistic missile programs as a strategic move with its near abroad allied program through the DPRK lucrative Black Market command economy processes.

By no means is this free to the DPRK as it has to be financed from Iran and in turn Iran gets the capability designs materials  through the technology transfer agreement all the where with all to make it theirs with no inspection regimes detection until it is a completed reality. This is what Iran has done behind the world nuclear agreement totally nullifying the intent and purpose. The leadership in Iran is deception personified like the DPRK they use mass psychological warfare and cultural deception  and repression with more death’s than the previous regimes making the former Soviet Union meek to their brand of authoritarian system of doing business. Deception is both governments way of life.

For Further information on the Russian/Soviet era technology transfer to the DPRK strategic ballistic missile programs See :

http://www.globalsecurity.org/wmd/world/dprk/nd-1-hist.htm

http://www.globalsecurity.org/wmd/world/dprk/nd-b.htm

http://www.globalsecurity.org/wmd/world/dprk/nd-b2.htm

http://www.globalsecurity.org/wmd/world/dprk/kn-11.htm

http://www.globalsecurity.org/wmd/world/dprk/kn-x-slbm.htm

http://www.globalsecurity.org/wmd/world/dprk/td-1.htm

http://www.globalsecurity.org/wmd/world/dprk/td-2.htm

http://www.globalsecurity.org/wmd/world/dprk/kn-14.htm

Images of the DPRK, 1.0-1.10 meter diameter upper stage solid motor test firing demonstrations observed by Kim Jung-un:

1. The DPRK solid propellant motor sea level or upper stage static test firing as viewed by Kim Jung-un It also featured either a cold high pressure hot gas ejection start canister or a staging separation followed by the full duration stage firing. Whether this 1.0 - 1.10 meter diameter solid motor tested here is an entirely new stage for a land based or sea based future missile system remains uncertain. However it does not match the 1.5 meter diameter solid motors of the indicated KN-X-15 design but is demonstrating the related technologies. How and where this is to be utilized is apparently to be determined within this DPRK Five Year Plan.

2. Close up of the base of the upper stage solid motor firing showing the outside base diameter ring that permitted either a cold hot gas ejection start canister to be separated or a staging inter-stage structure separation to be attached outside of the steering vanes protective housing. That outside steering actuator housing also has a back slopped away clearance to aid the ejection canister or inter-stage separation clearances.

3. 4. Kim Jung-un inspects the end results of the sea level or upper stage static test firing. The close up detail plainly shows the identical Pakistani, Chinese steering vanes design details as well as steering vanes actuators back housing design similar to the Iranian, Sejjil design.

5. The Chinese DF-15, 15A with its 1-1.10 meter diameter solid motor and its rear steering vanes nozzle design details showing the steering vanes actuators. See: http://www.b14643.de/Spacerockets/Diverse/Dong-Feng/index.htm

6. This is a rotated image of the illustration displayed in front of Kim Jung –un of the stage solid motor being tested with either a cold high pressure hot gas ejection start canister to be separated or a staging inter-stage structure separation to be attached outside of the steering vanes protective housing.

7. Behind Kim Jung-un lies the relatively short 1-1.10 meter diameter stage solid motor to be tested with either a rear cold hot gas ejection start canister to be separated or as a staging inter-stage structure separation. The stage test demonstration included a high pressure first stage starter cartage motor below the first stage propellant dome as a part of the start stage ejection system.

8. The Pakistani, single stage Shaheen-1 ballistic missile based on the Chinese provided technology assistance from their M-9, DF-11, DF-11A, utilizing a 0.88 meter diameter solid motor.

9. The Pakistani two stage Shaheen-II ballistic missile based on the Chinese provided technology assistance from their M-18 missile technology demonstration utilizing two 1.4 meter diameter solid motor.

10. Iranian Sejjil first stage solid motor steering vanes and rear housing configuration details

See: http://www.b14643.de/Spacerockets/Diverse/Sejil/index.htm

For further information on Chinese advertised space application solid motors images

See: http://www.b14643.de/Spacerockets/Diverse/SpaB_aerospace_motors/index.htm

There are also various chinese IAF, and IAC papers presented that are readily available on the space applied solid propellant motors from 1996-1997 and subsequent papers published as well as advertisement brochures.