Geoff FordenDPRK’s Stay Clear Zones

North Korea has declared the stay clear zones ( as pointed out by a number of people in the comments to my alert post). You can down load a Google Earth file of these stay clear zones here. These zones imply that North Korea is launching its rocket due East.

If its fired due East, why do the zones appear to tend to the South?
Before people get excited about this, you have to realize that a launched object remains in a plane that passes through the launch point and the center of the Earth. This plane’s intersection with the Earth’s surface at the launch point forms a line that, in this case, appears locally to go directly East-West. Once you get away from the launch point, the intersection of the plane appears to fall to the South (if the launch point is in the Northern hemisphere) Believe me, this is entirely consistent with a launch due East that takes full advantage of the Earth’s rotational speed.

Why stay clear zones? (Update)
North Korea issued these two stay clear zones to protect shipping etc. from the first and second stages as they reenter, which implies of course, that if the rocket is intended to orbit a satellite that it has three stages.


  1. Major Lemon (History)

    Geoff. Why do they need ‘stay clear zones?’ Do they think the thing might blow up or something?

  2. J House (History)

    Clearly the proposed flight path could endanger Japanese civilians,given a severe problem.
    Where will the line be drawn for these provocations?
    What evidence is there that a satellite is its intended payload?

  3. Geoff Forden (History)

    Please see the update to the post as to why they issued this notice.

  4. Major Lemon (History)


  5. PC (History)

    Thanks Geoff,

    Would the third stage of an assumed TD-2 SLV be the same as that of a 3-staged TD-2 missile? Or would it act more like a smaller kick motor for a presumed small satellite? Recognizing of course that its difficult to know exactly what the Norks are actually planning at this point…I’m just wondering how identical, staging wise, a TD-2 SLV and missile would operate.

  6. Andrew Tubbiolo (History)

    Is that 1st stage impact zone based on a pure gravity turn, or will they have have to give some extra loft to avoid hitting Japan? Oh wait, I think I’m showing my inability to read. These are declared safety ranges, not ones you computed….. Nevermind… Humm I’ll have to do some crunching myself, that range of 1st stage impact zones gives some useful performance numbers if you make some assumptions.

  7. Brian W (History)

    It is standard for most responsible States to issue air and maritime warnings about upcoming launches with keep out zones for aircraft along the flight path and re-entry zones for ships.

    The 3rd stage for an SLV is almost certainly going to be very different from one for an ICBM, because the flight profile for an SLV is different from an ICBM. An SLV needs to go up to altitude and provide forward speed, so it is likely that the 3rd stage will be a kick motor designed to do the latter.

  8. Jochen Schischka (History)

    The two safety-zones clearly do imply two things: It will be a three-stage-design (otherwise the second stage would not splash down at all – see Safir-2) and the first two stages will with high likeliness follow a mostly range-optimized trajectory (like a surface-to-surface-missile – otherwise, at least the first stage would not fall down so far from the launching point, see Brian W’s comment).

    If these safety-zones should not turn out to be some sort of deception effort (and the burnt-out stages actually do drop down there), then i think it is safe to say that the North Koreans plan to test a missile with surface-to-surface-characteristics of the first two stages (range ~4000km) masked as a “civilian” satellite launch (thanks to an additional kick-stage – somewhat similar to the israeli Shavit/Jericho-2)!

    I’m still expecting something like a modified Safir IRILV (with a longer payload-shroud for an additional kick-stage; liftoff-weight ~28t), maybe in combination with a heavier satellite or a higher orbit; the acceleration at start would probably be only meager ~1.2g in this case, but the kick-stage plus payload would weigh about the same as a hypothetical warhead. Launch would happen from Musudan-Ri to the east (capitalizing on the earth-rotation) into an orbit with ~41° inclination;
    Now i’m VERY curious if there will be some photographic evidence of the launch this time to prove or disprove this speculative configuration (the given ranges could be consistent due to preliminary analysis/estimation)…

    A different explanation could be an “Al-Abid”-like approach with five clustered Scud-C’s as the first stage, but in this scenario, the first stage would fall to earth at a much shorter range (~100km; delta-v ~1600m/sec; delta-v-gain due to earth-rotation ~350 m/sec), so i’d tentatively mark such a configuration as unlikely.

    BTW, the size and shape of the safety-zones might perhaps tell us something about the expected lateral and range-accuracy of the “Unha-2”-missile (if used as a two-staged SSM)…and i’m not really impressed by a missile with a maximum deviation in the range of several hundred kilometers (even a HUGE multi-Megaton thermonuclear warhead will not be able to compensate for that – not to speak of the ~4kt Pu-firecracker the DPRK demonstrated in 2006).

  9. JR (History)

    Inferring performance from the range safety zones is sketchy at best. The safety areas are designed to cover all of the places where a spent stage — not a weaponized payload — could come down. A spent stage has a ballistic coefficient (beta) in the low hundreds of kilograms/m^2 and will be breaking into many (relatively) lightweight tumbling pieces, whereas even a badly-designed payload should have a beta of a few thousand kg/m^2, and when it functions according to plan should remain intact the whole way down.

    So while a spent stage might have a CEP in the hundreds of kilometers, you’ll need to back out a payload CEP using good guesses for both the stage and theoretical payload ballistic coefficients.

    I do think that the orbital elements (and here I’m being generous and assuming they get to orbit) will help us figure out how good the lateral guidance is. We should be able to see whether the flight path really did stay directly over the drop zones or not.

    As for the engines, I’d bet on your cluster theory. The Iranian Safir fit on what looked like a Shahab-style TEL, but most drawings of the Unha-2’s ancestors show a significantly larger diameter first stage.

  10. Captain Ned (History)

    Any comment on the analysis by McKittrick over at Closing Velocity that the flight path appears headed straight at Hawaii?

  11. wise

    When Safir-2 was launched a lot of you were saying that it was based on the North Korean design. But now it looks like the North Koreans are expecting their second stage to land down range and not enter into orbit as did the Safir-2. Do you still maintain that these are the same design? The Iranian sites claim they are not.

  12. Allen Thomson (History)

    Sort of a random thought, but I wonder if the US Navy still has the deep-sea recovery capabilities it developed during the Cold War. Retrieving the remains of the booster stages, especially the engines, probably would be useful.

  13. Jochen Schischka (History)

    To JR:

    I agree with you, this is only the accuracy of the stage, not a hypothetical payload – but the accuracy of a warhead would certainly have to be about a hundred times (that’s two orders of magnitude!) better to have any military value, and we’re still talking about only HALF the range of a typical ICBM.

    As for “most drawings of the Unha-2’s ancestors”: I wouldn’t put too much faith in simple drawings (hey, i can draw a rev-eng LGM-118/peacekeeper-silo underneath the Musudan-launchpad, but that doesn’t mean this is what’s happening there in reality…) – let’s wait for photographic evidence to finally commit ourselves to a certain theory.

    That said, i’d find it more than strange if the North Koreans would actually have completely independently developed a totally different missile (from what money?) based on the same ancient soviet technology than the oil-rich Iranians (who did in fact without doubt obtain most of their ancient soviet missile technology via North Korea) in about the same timeframe for exactly the same purpose…

    BTW, maybe we don’t have all the information considering the Safir-2-launch. Perhaps this device was also three-staged (although the third stage would be problematic to fit into the small payload shroud of that missile if the orbited satellite was really the shown-around 40cm-cube), but we never heard about the second stage falling into the indian ocean off the coast of Kerala (this would make the performance-envelope of the Safir IRILV much more understandable – and i remember reading something about a 700km-range for the first stage of that launcher, which is hard to believe in conjunction with a trajectory not optimized for range). Has anybody access to information pointing in that direction? Did the Iranians also declare an international safety-zone off the indian coast? (If only we’d have access to the without doubt existing radar tracking data of the US Navy…)

  14. Murray Anderson (History)

    Captain Ned:
    Based on Google Earth, it passes south of Hawaii, about 700 km away at closest approach.

  15. JR (History)

    Capt Ned, he connected the dots with a crayon. The fact that he penciled in “Pearl Harbor” in a bull’s-eye graphic tells you he’s got an axe to grind.

    Open up Google Earth and trace a line from the launch pad to the northernmost corner of the second-stage closure area. Hawaii is on a heading of ~83 degrees. The closure area, even if you steer aggressively close to Hawaii, is more like 92 degrees. At the point of closest approach, the vehicle is likely to be ~100km south of Hawaii. That might be close to a politician or a layman but it’s certainly not “straight at” Hawaii.

  16. Allen Thomson (History)

    > the flight path appears headed straight at Hawaii?

    It isn’t: POCA to the major islands is ~ 700 km to the SSE.

  17. Azr@el (History)

    The only thing more difficult to grasp than the improbabilities of the Safir carrier lofting a payload at all seems to be accepting that it is not a rebuilt soviet irbm from the 50’s. Something is obviously very different about it, something that allowed the Iranians to loft a two stage to orbit rocket. This is definitely far beyond the capabilities of Soviet tech from the 50’s and 60’s and those that refuse to accept this fact doubt aspersions upon their own grasp of current circumstances. That being said, the North Koreans apparently need a three stage rocket to loft a leo payload. The additional eastward boost of Iran’s lower latitude launch does not appear to be the driving factor, so we must assume that North Korea is using either less efficient engines, less energetic fuel/ox or a more parasitic steering mechanism to account for their need for an additional stage.

    The Safir without the addition of high thrust solid assist motors seems unable to liftoff with a substantial third stage. Thus it is highly unlikely that the NorKor carrier rocket is a Safir +3rd stage.

  18. Murray Anderson (History)

    If the first stage of the Safir burned out at 70 km with velocity 2.4 km/s then the range from burnout of the discarded stage , max height, and velocity at apogee are as follows:
    Angle Range Height Velocity
    30 641 152 2.05
    32 655 161 2.01
    34 667 172 1.96
    36 675 182 1.91
    38 681 193 1.86
    40 684 204 1.80
    41 685 209 1.77

    The max range is for a velocity vector inclined 41 degrees to the horizontal but an angle of around 30 degrees is more likely for a satellite launch to low earth orbit. The gravity losses are lower, and the ultimate height will be higher than 152 km as the second stage drives it along the trajectory.
    Note that I’ve actually taken the range from burnout to 15 km above the ground, to try and take into account the effect of atmospheric drag at the far end.
    I recall reading the 700 km figure too, and it seems difficult to reconcile with a burnout velocity of much more than 2.4 km/s. However, that gives a delta-v for the first stage of maybe 3.7 km/s, and maybe 5.6 km/s for the upper stage. Is that really out of the question?

  19. Paul (History)
  20. Tal Inbar
  21. Jochen Schischka (History)

    To Paul and Tal Inbar:

    Very interesting material – thanks to both of you!

    To Azr@el:

    1.) There can be no doubt that the Safir-first-stage is a rebuilt/modified Ghadr-1/Nodong-B (same diameter, exactly the same engine compartment, the same Scud-B-fins, but simplified and stretched tanks and added upper-stage based on an Isayev ZhRD 4D10 two-chamber-vernier-engine from the R-27/SSN-6/Serb).

    2.) There is no doubt that the Ghadr-1/Nodong-B is a rebuilt/modified Shahab-3/Nodong-A (same diameter, exactly the same engine compartment, smaller Scud-fins instead of the large Nodong-fins, but modified tank-layout with combined features of Scud-C and R-12 and compacted guidance-compartment with features of the Scud-C plus different warhead-section).

    3.) The Shahab-3/Nodong-A is with high probability identical with the soviet R-15-project cancelled in 1958 (only with a conventional warhead instead of a nuclear one and on a road-mobile MEL instead of a project-639 submarine)! This missile looks EXACTLY like an upscaled R-17/SS-1c/Scud-B (although the R-17 is more likely a miniaturized version of the earlier R-15)!

    Please compare this picture (Safir-1):

    to that picture (R-17/Scud-B):

    Take note of the size and details of the fins, the proportions and general make-up of the jet-vane-actuator-boxes, the turbine-exhaust at the bottom, the three-fold pneumatics coupling at the top and the two boxes to the left and to the right of the engine (marked “Sh37”/“Sh38” for “Shtepsel” = connector/plug in russian on Scud-B and “SJ37”/“SJ38” on the iranian device respectively).

    As for “definitely far beyond the capabilities of Soviet tech from the 50’s and 60’s”: So the Russians couldn’t modify a single-staged IRBM into a two-staged LEO-launcher? What else is the Kosmos-2/11K63 (see for example here:

    I do not understand why you have problems accepting that the iranian Safir IS IN FACT a rebuilt soviet IRBM from the 50’s/60’s.

    In case of the north korean Unha-2/Taepodong-B, let’s wait (for photographic evidence) and see (how this device actually looks like).

  22. Azr@el (History)

    Yes, to be more precise, it is far beyond the capabilities of the late 50’s, early 60’s soviets to launch a two stage to orbit non-cryo carrier rocket. The Kosmos family, as you well know, burned in LOX (The soviets were probably able to launch a two stage to LEO non-cryo by the late 60’s , early 70’s ;N204/UDMH). If the Safir burned in LOX, then mystery solved and I would concede every point. That does not seem to be the case.

    Again, until someone can explain the performance of the Safir; we must accept that external similarities of the Safir to other projects must be artifacts of economic decisions to save money in the machine shop.

  23. Jochen Schischka (History)


    Only the upper-stage of the Kosmos-2/11K63/B-1 burned LOX/UDMH. The lower stage was an almost unmodified R-12/SS-4/Sandal burning AK-27I(IRFNA)/TM-185(Kerosene). (I agree with you, there are no signs for LOX in case of the Safir IRILV.) Don’t underestimate the advantages of dense propellant-combinations in lower-stage-applications!

    In respect to the upper stage of the Safir, in fact we ARE talking about late 60’s, early 70’s Amyl(NTO)/Heptyl(UDMH)-technology in form of the R-27/SSN-6/Serb vernier-engine!

    And what would be more economical than simply using an existing, probably even home-made IRBM to base the first stage of a multi-stage missile on (no need for expensive additional tooling, unfamiliar materials, untried production-processes, untested engineering-solutions etc.)?

    BTW, apart from the smaller fins, i can’t find ANY differences in the outer appearance of the engine compartments of the Shahab-3/Nodong-A, Ghadr-1/Nodong-B and the Safir IRILV – similar dimensions, the same hatches for maintenance in the same places, identical numbering scheme…so with high probability, this IS the same engine, albeit possibly uprated in case of the Safir (but if i buy a Peugeot 405 and tweak the turbo to squeeze 180hp out of the factory-made 144hp-engine, it’s still only a Peugeot 405, isn’t it?).

  24. Andy (History)

    It will be interesting to see if North Korea will make this a multi-missile event (scuds, anti-ship missiles, etc.) like it has done in the past. If they really want this launch to be viewed as a legitimate satellite attempt, they should keep the rest of their missiles stowed. Will they? I won’t hazard a guess at this point.

  25. Bruce MacDonald (History)

    As a graduate of International Relations and a satellite observer I really ought to start putting comments on this excellent website, so here goes…

    It seems to me that the DPRK is missing a trick here. Assuming this really is an attempt at an orbital launch and not just a pretext for another IRBM test, I am struck by two thoughts.

    First, the choice of 41° for i. I would want a higher value for i in order to achieve maximum coverage of the Earth’s population zones. North Korea is limited here, I suppose: is a due East launch the only azimuth available from the launch centre?

    Second, the choice of payload. Omid is not easily visible – I recorded it recently at magnitude +6, flashing regularly to magnitude +4 – and assuming a similar performance to the Safir 2 (perhaps even the same design?), for maximum propaganda value I would go for a balloon sat which would give much greater reflective surface volume for the same mass as 2009-004A (27kg).

    I look forward to see what the DPRK have up their sleeve. I suspect it’ll be another dud, though.

  26. Azr@el (History)

    Lox’s density is in the same ball park as Kerosene, it’s just a nightmare to deal with if your intent is to fashion an IRBM. On a digressive note, personally I’ve always thought the route to routine and somewhat affordable space access would be something along the lines of an expendable high thrust KerLox base stage and a high isp LH2/LOX upper stage with a potentially recoverable engine module.

    Back to topic: Without taking away from their achievement; Iran’s Safir program is almost definitely a cover for their ballistic missile program. It seems almost a given that under deployment the Safir first stage would not deploy with a second stage; unless a maneuvering separating warhead bus could be termed a second stage. The thrust to weight ratio and the complicated mating procedure seems to preclude a two stage Safir IRBM. Thus we are left with the question; if Iran is using their space program as a cover for their IRBM program what is the point of the test? To test an upper stage that they’ll never deploy operationally? Obviously not, they must be testing some improvement in the base stage.

    Maybe they’ve souped up the base stage ala the Peugeot 405(P.S. avoid those cars; I once saw one or it’s Romanian clone catch fire in Marseille and it wasn’t even Christmas) analogy but if they can field these high performance Shahab 3’s then what is the difference?

    The Shahab 1 is scud; 1950’s, the Shahab 2 is a souped up scud in Hangul; still the 1950’s, the Shahab 3 starts to dissolve the timeline analogy. When you have ancient designs reworked and significantly improved with modern knowledge do you still have 1950’s tech? Or do you get surprised with things like the Safir?

    North Korea’s program seems to have diverged from Iran’s significantly. Rather than continue souping up the base stage they seem to be going with more staging as their route to a micro leo launcher. North Korea’s program seems to be more about a quick and dirty symbolic launch to preempt South Korea’s turnkey-ski attempt at space shot. Pyongyang has most likely cobbled together whatever fits to get something convincing in the sky. There seems to be no ulterior motive behind their program.

  27. Allen Thomson (History)

    Bruce MacDonald, a SeeSat veteran satellite observer said,

    > First, the choice of 41° for i. I would want a higher value for i in order to achieve maximum coverage of the Earth’s population zones. North Korea is limited here, I suppose: is a due East launch the only azimuth available from the launch centre?

    I have little idea of North Korea’s requirements for reconnaissance, if indeed they have any. Since they’re north of South Korea, a due east launch from Musudan-ri gets them that coverage.

    What we do know is that they don’t mind overflying Japan. So, assuming that they don’t want to go over South Korea or Russia, that gives them an azimuth arc (not orbital inclination (i)) of about 58 to 180 degrees from Musudan-ri.

    I think they’re using a due-east launch because it actually is, and can therefore be claimed to be, the logical first step to getting orbital capability.

    IMO, the crucial question is the lift capability (aka throw weight) of the booster. Observation of what goes into orbit, if anything does, can help address that question. So observe! Report the visual magnitude, decay rate, etc.!

  28. Jochen Schischka (History)

    To Azr@el:

    Please note that Shahab-2 is SS-1d/Scud-C; This is NOT a “souped up Scud in Hangeul”, but a late 60ies/early 70ies soviet 500km-missile-upgrade (first flight in Russia in 1965; so this was definitely NOT designed by the North Koreans!) for the R-300 Elbrus-missile-complex (with the same engine and identical dimensions to the original 300km-R-17/SS-1c/Scud-B, which was itself originally planned as a dimension-compatible turbopump-upgrade-missile for the R-170 Zemlya-missile-complex of the pressure-fed R-11M/SS-1b/Scud-A).

    And Shahab-3/Nodong-A is NOT “dissolving the timeline analogy” – as the soviet R-15, this is some sort of bigger ANCESTOR of the R-17/SS-1c/Scud-B. Thus, the Shahab-3 is even OLDER 50ies-technology than the Scud-B!

    Inhowfar is this “ancient designs reworked and significantly improved with modern knowledge”? (That could, of course, to a certain extent be said about the Ghadr-1/Nodong-B – which seems to be in fact an upgrade of the vintage soviet R-15 with engineering solutions from the R-12/SS-4/Sandal and the SS-1d/Scud-C…but i’m skeptical if this could have been done by the Iranians or the NK’s without outside help, since both do not own R-12/SS-4/Sandal!)

    I don’t follow you (at least not yet – maybe we’ll soon have corresponding evidence proving or disproving my theory) on “North Korea’s program seems to have diverged from Iran’s significantly” – according to my interpretation, it’s more like the Iranians are the guys with the money (at the moment – there were also close ties to the iraqi missile-program back in the 80’s/90’s!), while the North Koreans are the proxy-salesmen (getting compensated with “payment in kind”) for the Russians (who like to stay in the shades for obvious reasons)…

  29. Azr@el (History)

    To clarify your confusion; the Shahab 1 is the Iranian produced version of the Hwasong-5 which is more or less an exact replica of the R-17E i.e. the SS-1C Scud-B. The Shahab 2 is the Iranian produced version of the Hwasong-6, which is most definitely not the SS-1d Scud-C. U.S. intel, in it’s infinite capacity for incompetence, did term them Scud mod C’s or Scud-C like to account for their functional similarities to the Makeyev OKB extended version of the R-17. But under the hood these are two completely different beast. And finally the Shahab 3 is the Iranian version of the of the 1.25 diameter Nodong A which is not related to the .88 diameter Soviet R-17 VTO SS-1e Scud-D project, even though western intel often terms it a “Scud D’.

    Speculation that any North Korean or Iranian missile is based upon the R-15 or the R-12 are groundless rumours with little or no basis in fact. Also the Iraqi Scud-B ER program, the al-Husayn, has no relation to the Iranian or North Korean missile programs, there were no close ties between Iran and Iraq pre-“Liberation of Baggdad” and the Iraqi-Argentine-Egyptian program seem to have been far inferior to the North Korean-Iranian effort seeming to negate any benefit Iran could derive from holding it’s nose to deal with a sworn enemy.

  30. Jochen Schischka (History)


    Shahab-1/Hwasong-5 (I’m not 100% sure that this isn’t Hwasong-1): agreed (although i’m not so sure of the “iranian produced” part – more likely, they only re-assembled the missile-sections after transport).

    Shahab-2/Hwasong-6 (or possibly Hwasong-2): Why do you think this is something different than Scud-C? On which evidence do you base your assumption that “under the hood these are two completely different beasts”? Same diameter, same engine, same guidance-compartment, same jet-vanes, same length (10944mm as R-17E/SS-1c/Scud-B with conventional warhead – NOT stretched, like C.P. Vick paints them!), same common-bulkhead, same burn-time, same range-capability…so if it looks like a duck, and walks like a duck, and talks like a duck – you assume that this is a baby elephant in brilliant disguise with an astonishing talent for impersonating ducks??? Yeah, right, since the paint-job is different…

    Shahab-3/Moksong (possibly Moksong-1): I agree with you, Nodong-A is DEFINITELY NOT the R-17VTO Aerophon/SS-1e/Scud-D; Please note that i never made such an assertion!

    (The same holds true for the northkorean/syrian 0.88m-ER-Scud (-> Kuwolsan/Hatay-incident of 2005), which is also frequently and incorrectly addressed as “Scud-D” – This looks more like a professionally perfected Al-Hussain/Al-Abbas-hybrid based on Scud-C instead of Scud-B to me.)

    Obviously you completely misunderstood what i was trying to say in respect to a northkorean-iraqi (definitely NOT iraqi-iranian!) link back in the 80’s/90’s; Do you think it is mere coincidence that the iraqi S-13-project, the second stage of Al-Abid, the Al-Kharief and the northkorean Nodong-line (and thus “coincidentally” also the pakistani and iranian missile systems Ghauri, Shahab-3, Ghadr-1 and Safir) all use the 1.25m diameter (look for example on pages 437, 439, 440 and 442-446 of the UNMOVIC-compendium – although i am not in 100% agreement with all of the UNMOVIC’s interpretations: e.g. the “S-13” drawing on page 446 depicts an iraqi contingency-project perhaps more correctly identified as “S-110”: a modified 1.25m(Nodong)-airframe with 110 seconds burn-time and a modified Scud-engine…there were obviously production-difficulties of the 30t-class Nodong-engine in 1989/1990 – see first test of Moksong/Nodong-A in the DPRK in 1990)? Can it also be mere coincidence that the iraqi Al-Hussain “short” or H3 used EXACTLY THE SAME 60l-pressure-gas-torus as the northkorean Scud-C (see Kuwolsan/H3-wreckage in Tel-Aviv)?

    It is obvious that all this is vintage soviet technology, if you like it or not. Please investigate the R-15-link for yourself – you might notice the “coincidental” similarities in size, weight and range-capability! (BTW, the 1.25m-diameter is the same as on R-13/SSN-4/Sark and R-21/SSN-5; see exhibits of these missiles in russian museums)

  31. Azr@el (History)

    I’m not disputing the Soviet heritage of the Hwasongs or the Nodongs, I’m merely pointing that that development of the Soviet scud series has diverged from North Korean and Iranian implementations. Much like Linux has various branches all basically variations on a theme so too has this category of missiles. Just like amongst various incarnations of Linux one can find strong commonalities so too can you discover artifacts of a common heritage between soviet scud C’s and hwasong 6’s and to an extant the Iraqi Al-Husayan project which is basically an underloaded scud-b.

    But let’s look at these projects; the soviet scud-c project was a flop, the flow fluctuations in the turbopump of the engine grew worse as they tweaked for higher performance, result: accuracy suffered range was good. The Hwasong6 was modified much later, NorKor had access to much more advanced guidance packages and less knowledge of engine design, result: very good accuracy not as much range as the soviet scud-c. The Iraqi project was a German outsourcing affair after the collapse of the project condor II, the Iraqi’s imported scud-b’s and foreign technicians to reverse engineer the rocket. The al-husayan itself was merely achieved by reducing the payload, various other incremental modifications were achieved to aid in developing a chem/bio war head. No major engine modification were ever attempted. All of the Iraqi derived Scud-B modifications were tumblers, a problem NorKor solved in their Hwasong-6 project. Note that Iraq’s attempt to modify length of their scud-b’s resulted in such a high degree of instability that the Iraq’s cancelled the Al-abbas, their lengthened scud-b with an attendant throw drop to ~140kg. Al-Hijera, i.e. the shortened al-husayan, is a scud-b optimized for a larger than normal warhead and a shorter range, it’s diameter is .88m, not 1.25m. From this you can see that had NorKor aided Iraq’s scud-b er program than Iraq would have had a much more advanced project. There is a background as to why the NorKor’s and the Iraqi’s never hit it off but it’s a bit tedious.

    Again, from the preceeding we can see that different choices caused widely divergent programs to develop. NorKor’s decision to modernize their Scud-B’s at a later date than the Soviet Sucd-C program resulted in a more capable missile albeit with a shorter range and less throw mass. Iraq’s attempt to fiddle with throw mass, fuel mass ratio’s without undertaking any modifications to the Isayev R-17 engine, mass reductions or improving the guidance package of the missile resulted in the worse of both world’s; low throw mass and a high degree of inaccuracy.

    In the end, no one can deny the Soviet heritage of the Hwasongs and Nodongs, no more than one can deny the German heritage of the Saturn-5, but everything had a start and we all walk on the shoulders of those who came before us; so what? Have the Iranians and the North Koreans significantly improved upon the Soviet Scud-B’s to produce the Hwasongs, an incremental improvement of the Scud-B, and the the Nodongs, a new line of missiles, the answer is yes. This seems like a basic thing, modify and play around with something that works thus developing core skills, then start building your own designs using off the shelf components and finally make your own design from scratch. But even your own design will have an influence of from the first thing you cut your teeth upon. I see the Iranian and North Korean programs following this education model exactly.

  32. Jochen Schischka (History)

    On the Scud-C, the Russians did NOT tweak the standard Scud-B-engine! Why should they do that? 13 tons SL-thrust is more than enough for a missile with a take-off-weight of ~6.1 tons! And why should this have an effect on accuracy, since the range/cutoff-velocity of the Scud is controlled by a PIGA (1SB12)??? Engine problems would affect the maximum range (due to degradation in overall engine efficiency), NOT the accuracy! (Where did you get these strange ideas from?!?)

    That said, the accuracy of the Scud-C was in fact worse than that of the Scud-B – simply because the Russians tried to use basically the same Horizont-Vertikant-guidance-package (longer range -> bigger inaccuracy)! The typical russian solution for this was designing a warhead with a bigger area of effect (and in this case also a reduced mass of only ~750kg) for that missile (the RA-104 with ~300kt (thermonuclear); the 269A and the later RA-17 of the Scud-B had yields in the range of ~20kt (unboosted implosion-type) and ~80kt (fusion-boosted implosion-type) respectively; note that the RA-17-upgrade allowed the Scud-B a “first-shot-kill”-capacity).
    You can’t be serious about a “much more advanced guidance package” on the Hwasong-6/Shahab-2. There is NO SIGN of anything but EXACTLY THE SAME guidance package as on the Scud-B (apart from some minor range/CoG/burn-time-dependent adjustments to the 1SB12, 1SB13 and 1SB15).
    The only difference between the soviet Scud-C and the north-korean/iranian devices is, as far as i see, that they didn’t get the nuclear warhead from the Russians, but a conventional one with similar mass and dimensions (EXACTLY like on the export version of Scud-B; also note that the Russians (almost – except for training-issues) exclusively used nuclear warheads on their own Scud-B’s because of the low accuracy). Thus, the North Koreans/Iranians don’t have a “more capable missile albeit with a shorter range and less throw mass”, but instead are stuck with a “weapon” of very doubtful military value: the maximum area of effect of their warhead is MUCH smaller than the CEP of the missile, not to speak of the maximum deviation. They statistically can’t hit what they are aiming at unless the target stretches over several kilometers – and in this case it is VERY unlikely that they will be able to destroy or even considerably damage such a large, wide-spread target with only a single or even several hits by a conventional ~750kg-warhead (in essence, the same applies also to the Nodong-A).

    I think the North Koreans and the Iranians are farther behind in their missile-designing-capabilities than what you are inclined on crediting them with: The Scud-B is simply bought, Scud-C and Nodong-A are license-produced and Nodong-B and Safir IRILV are obviously examples of “building your own designs using off the shelf components”; I have not yet seen any sign of “own design(s) from scratch” (aka liquid-fueled missiles with different diameters than 0.88m and 1.25m).

    Now some comments on your comments on the iraqi missile program:

    “after the collapse of the project condor II, the Iraqi’s imported scud-b’s”

    So the “Condor-II”/Badr2000-project collapsed before 1974 (when the Iraqis got their first shipment of Scud-B’s, see ISG final report p.81-90)?

    “al-husayan itself was merely achieved by reducing the payload”

    (Partially) wrong – the Iraqis reduced the payload to ~450kg (~230-280kg of explosives – where did you get the 140kg-figure from?!?), but ADDITIONALLY stretched the tanks (thus extending the t-burn to 80sec on the S80 Al-Hussain, and later even 100sec on the S100 Al-Abbas), rearranged the pressure-gas-bottles because of center-of-gravity-issues (on the S80-H2 and S100) and made necessary adjustments to the guidance-package (similar, but not identical to that of the Scud-C).

    “All of the Iraqi derived Scud-B modifications were tumblers, a problem NorKor solved in their Hwasong-6 project.”

    Wrong – the iraqi missiles simply BROKE UP on reentry due to higher speeds (the Scud-B also “tumbles” on reentry!) and the not-too-expertly lengthened airframe, thus the “shortening”-program S80-H3 (which used the toroidal pressure-gas-tank of the Scud-C!); but they also worked on a real cure for this problem: a separable warhead (see UNMOVIC-Compendium p.430-433)!

    “cancelled the Al-abbas”

    Wrong – they only couldn’t finish the development of that missile (see UNMOVIC-Compendium p.427-434) before 1991. (This is possibly where the syrian/north-korean Scud-ER comes into play…an outsourced, post-1998 Al-Abbas?)

    “Al-Hijera, i.e. the shortened al-husayan, is a scud-b optimized for a larger than normal warhead and a shorter range”

    Wrong – Al-Hijara (= “the stone”/“the rock”) simply was an S80-H3 with a ~450kg dummy warhead (~230-280kg concrete-filling); This was meant as a (VERY optimistic) “penetrator”-warhead for the israeli Dimona-plant.

    “it’s diameter is .88m, not 1.25m”

    Do you intentionally ignore all the iraqi 1.25m-projects (S-13/“S-110”, Al-Abid second-stage, Al-Kharief; probably also Al-Tamuz, although the UNMOVIC-Compendium states otherwise) that i cited or did you simply not bother with reading the UNMOVIC-Compendium (this can be downloaded at The S100 Al-Abbas is NOT to be mistaken for the S-13!!!

    “no more than one can deny the German heritage of the Saturn-5”

    Did the Saturn-5 have a diameter of 1.65m (like the Aggregat-4/V-2)? Did the Redstone? Or the Thor? Or the Jupiter? Now let’s look at sovietrussian missiles: What was the diameter of the R-1/SS-1a/Scunner? Or the R-2/SS-2/Sibling? Or the R-5M/SS-3/Shyster? Or the R-12/SS-4/Sandal? Even the 0.88m-diameter of the Scud-line can be traced back to the german Wasserfall-SAM (since the Russians in the end captured the german production-plant(s) at/around Nordhausen PLUS the development site at Peenemünde PLUS the late-war proving-grounds at Blizna and “Tucheler Heide” PLUS a considerable amount of german production-engineers, this should not be surprising)…