Geoff FordenFirst Guesses: DPRK’s Launcher


Click on the image for a larger version

Everybody and his brother is using the announced splash down zones to try to model the North Korean satellite launcher scheduled to be test fired sometime between April 4th and 8th. So I thought I’d put in my two cents worth to get the ball rolling. First, however, I’d like to contrast this launch, which not only has notified stay clear zones, but will take place during daylight hours. I think North Korea is definitely suffering from publicity envy of Iran’s successful launch!

Now on to the missile design. I’m going to proceed along a slightly different path than I think most of my friends are taking and use the sorts of preliminary design techniques I discussed for designing a hypothetical Iranian ICBM well before the successful Safir launch. While these stay clear zones mentioned in my previous post presumably reflect larger areas than North Korea really expects for its uncertainty on where the first and second stages should splash down, they can be used to estimate some of the characteristics of both the flight path and the rocket. We do, however, have to first make some educated guesses on where the first and second stages burn out and the angles of the rocket at those positions.

The most interesting result was for the first stage. If we factor in atmospheric and gravity losses, the first stage has to deliver a total of almost 3.8 km/s and burnout with an angle of roughly 65 degrees (from the horizontal, which is very consistent with the design that finally emerges). This corresponds to a total mass ratio (the total launch mass of the rocket divided by the empty first stage plus fueled second and third plus the payload, which I assume to be 278 kg) of 5.4. It’s going to be a big rocket! I also assumed a modest increase in first stage power with an Isp=250 s and a thrust to weight ratio of 1.5. Then, optimizing for a three stage rocket launching a satellite into orbit with the second stage having an Isp=275 and the third having Isp=250, I get an elliptical orbit with an apogee of over 1100 km and a perigee of 300 km. I also had to have a substantial “negative” loft angle for the last third of powered trajectory, something that is fairly common with, among other rockets, the Soyuz rockets.

The entire rocket weighs in at just over 85 tons. Clearly, I could have gotten a larger payload into a more circular orbit. Just as clearly, if I had used SCUD-type technology the rocket would have had to be substantially bigger. (My estimate for that would have been over 118 tons to put a 100 kg satellite into a similar orbit.) Using SSN-6 technology would allow North Korea to substantially reduce the size of the rocket and all the associated problems designing, building, and launching such a large rocket would entail.

So what does this imply for a North Korean ICBM? If I remove the third stage, which I assumed was SCUD-type technology mainly because I didn’t think the North Koreans would bother expending a lot of effort on it, then the two-stage missile could loft a 1000 kg warhead over the pole a distance of almost 12,000 km. You can download my model of the North Korean satellite launcher here but you have to use the most recent version of my missile simulation program to run it because of changes to the pitch program I had to introduce to simulate satellite launches. (Sorry, there isn’t an updated help file yet, but hopefully if you explore around a bit it should be self explanatory.)

I know of a several people who are working on “designing” the North Korean launcher using these splash-down zones to mine important design information. I expect that their models will be of a higher fidelity. But until we at least see pictures of the launch vehicle I think my method is sufficient for these purposes.

Comments

  1. Geoff Forden (History)

    After having written this post, I realized that some readers might legitimately be wondering: why such a large missile? Surely a smaller missile could also place its first two stages down in these zones? I agree. But reports surfacing in the press have mentioned large cylindrical objects being shipped by train to the launch site and it is taking the North Koreans weeks to assemble this thing so I rather arbitrarily picked a rocket size that has a thrust of four times the Nodong as a starting point. Once you make that choice, the rest of its capabilities fall into place. As I said in the post, a picture will clear up a lot of these remaining questions.

  2. Murray Anderson (History)

    Are you sure that isn’t 65 degrees from the vertical, 25 degrees from horizontal? That would be consistent with other rockets. For example, the Rockot user guide, page 3-10, gives an angle of 23.9 degrees at first stage burnout. The burnout is at 3.1 km/sec, but even so an angle of no more than 30 degrees is likely, unless they needed a very lofted trajectory.
    As for performance, I think Isp of 250 is low for an SSN-6 engine. Wouldn’t it be more like 290 seconds?

    Reference: Eurockot User Guide, Chapter 3: General Performance Capabilities: http://www.eurockot.com/pb-pic/20041084.pdf

  3. Geoff Forden (History)

    Actually, 65 degrees is what I calculate (From J. F. White’s “Flight Performance Handbook for Powered Flight Operations”) as being optimal for the assumed Isp and thrust to weight ratios. As to the Isp, I wasnt modeling the SSN-6 but a modestly improved first stage.

  4. Peter J. Brown (History)

    There was a report yesterday that no assembly of the missile has actually taken place yet at Musudan-ri. Do you have any confirmation of this? An update on the status of the assembly process woud be welcome.

  5. Geoff Forden (History)

    Peter, I’m afraid I don’t have any information about that. That report just emphasizes how much hard information we do not have on the launch.

  6. Jochen Schischka (History)

    To Murray Anderson:

    I tend to agree with Geoff; the higher burnout-angle for the first stage would make more sense for a space-launch-application (please note that the Rockot is an UR-100NUTTH/SS-19/Stiletto ICBM with an added Briz-upper-stage and payload-shroud; This is NOT an optimized space-launcher!).
    And i’d be VERY surprised if the North Koreans should in fact have mastered building CLOSED-CYCLE, HIGH-PRESSURE R-27/SSN-6/Serb main-engines (BTW, Isp-vac for the 22t-main-chamber alone without the 3t-open-cycle-vernier-engine would be over 300sec; Another interesting characteristic of this engine is that it was designed for hot-launching from a salt-water-flooded submarine-tube at a depth of 40-50 meters – so it’s not even Isp-optimized for ground-launch applications, a higher area-ratio would yield even higher Isp!), so a safer bet for the first stage of the “Unha-2” would be the NoDong-engine (or the Scud-engine) with ~250sec Isp-vac in my eyes.

    But i’m still VERY skeptical considering clustered engines on that missile (the best i can imagine for the NK’s is strapped-together Nodongs or Scuds – i’m inclined to rule out completely new large-diametered body-structures unless i have hard photographic evidence).

    A question to everybody:

    Can we really positively definitely once and for all rule out with absolute certainty the possibility of the Safir IRILV being perhaps also three-staged? (I am not 100% sure of that, although all available evidence seems to point in that direction – the question is, do we have sufficient evidence at hand to exclude that possibility?)

  7. Azr@el (History)

    Yes, we can safely say the Safir is a two stage to leo configuration. Can it in some future incarnation sport a very small third stage kick engine? Possibly, but it seems to be already bumping it’s head against the upper limit provided by it’s base stage thrust.

  8. Murray Anderson (History)

    Jochen:
    A higher burnout angle does not make sense for a space launch to low earth orbit. It’s the other way around, since the ballistic missile is supposed to maximize range on a suborbital trajectory, whereas the launch to low earth orbit should minimize the gravity loss for the second stage, subject to other constraints.
    In fact, the same low angle at burnout is found for the Saturn 5, about 24 degrees at a velocity of 2.7 km/sec (Saturn 5 Flight Manual SA-503)

  9. Jochen Schischka (History)

    Murray:

    I think Saturn 5 (the manned moon-rocket) was again NOT optimized for (circular) LEO-injection (and we could start a discussion inhowfar that launcher was optimized at all – but it surely did the job, no question); The burnout-angle depends in my opinion on some physical constraints, but also mostly on your personal philosophy and other (technical, political etc.) restraints.

    Let me expand on my thoughts on this issue: The first stage has to be ground-launch capable, so you can’t realize an ultra-Isp-engine (due to limitations in area-ratio because of the ambient-pressure – also you’ll have to achieve at least enough sea-level-thrust for ~1.2g liftoff-acceleration, and since your propellant-combination only delivers a limited amount of chemically stored energy per burned kilogram, the higher the Isp, the quadratically lower your thrust! This is basically why LOX/LH2-lower-stages are not a very good idea…and typically have to be supported by high-thrust-low-Isp-high-noise/vibration-solid-boosters…); Upper-stage engines can on the other hand be optimized for vacuum-operations (also no aero-drag -> “flight” at much higher angle-of-attack possible without overstraining the structure!). Furthermore, upper stages can be built more lightweight because they don’t have to support as much weight as the first stage (and, since they are characteristically smaller than the first stage, more expensive aka less dense materials can be used without too much of an overall cost-explosion).

    Do we agree that the “circular” portion of delta-v will be MUCH higher than the “height” portion for low orbits (please note that this will change dependent on the intended orbit’s height/geometry)?

    Where would you want to primarily make your gravity-losses, on the low-efficiency lower-stage or on the high-efficiency upper-stages? (This question is not as easy to answer as it might seem, and this is also exactly where the philosophy-thing comes into play…)

    And keep in mind that higher aero-drag-losses might come along with lower first-stage-burnout-angles (if this prolongs the flight-duration at high speeds in the dense part of the atmosphere – the trick is to leave the atmosphere on the shortest way as fast as possible, but also at not too high velocities…).

  10. David Wright

    Geoff,

    As you know, I’m one of the people who have tried to model the NK launcher, based on my past work on the NK missile program and looking at the Chinese development of its missiles. For comparison, my model and results are described at:
    http://www.ucsusa.org/nuclear_weapons_and_global_security/space_weapons/technical_issues/an-analysis-of-north-koreas.html

    Even though our models have roughly the same launch mass (about 80 tons), your launcher is considerably more capable than mine. That is partly because you assume higher specific impulses than I do, but the biggest difference is that you assume a mass fraction for stage 2 of 90%, while I use 81%. My number is based in part on looking at the Chinese Long March-1 launcher, as I discuss in my paper. That launcher, which I think is likely more advanced than the Unha, has a second stage mass fraction of 83%, and my assumption is that NK would probably not do as well. The difference in the mass fractions alone leads to nearly a 40% difference in total delta-v provided by the second stages of our two models. When you include the difference in specific impulse, your second stage model gives 50% higher delta-v than mine. This would be an important issue to try to sort out.

    On the issue of clustering engines: I had a chance in the 1990s to talk to one of the Chinese engineers who worked on the development of the DF-3 missile, which is essentially the first stage of the LM-1, and has four clustered engines. He said that they expected clustering would be difficult, but found that it was much easier than they expected.

    David Wright

  11. Geoff Forden (History)

    David,
    I agree that my structure fractions are “optimistic” and that they undoubtedly are the reason why my two stage calculation for the range are so large. On the other hand, one interpretation for why the so-called Taepodong 2 failed in 2006 failed is that it structurally collapsed. Perhaps that indicates that North Korea is attempting to build lighter rockets?

    But perhaps a more important reason is that I, for one, certainly failed to appreciate the advances Iran has made in its missile development program with regards to its Safir missile. I think it is important that we start our discussion of North Korea’s launch with a wide verity of models. Hopefully, that will prevent us from missing important clues when we actually get some “hard” data on the Unha.

  12. Jochen Schischka (History)

    To Azr@el:

    Can we REALLY be 100% sure that Safir-2 did NOT use a small unguided (?) third stage (i’m thinking along the lines of a ~1m-long 333mm-solid-booster, possibly spin-stabilized, INSIDE of a ring-like guidance compartment – although such a configuration is admittedly highly speculative)?

  13. Geoff Forden (History)

    Jochen,
    I don’t think we can be 100% certain of anything. I had hoped that the experimental data as to drag and visual brightness would settle this issue but I have to admit that those are still ambiguous; at least to more of a degree than I was hoping for. The most convincing piece of evidence is, for me, given Iran’s many official statements that it was a two stage missile, the lack of a contradiction from the US who I think was closely watching the launch.

  14. Murray Anderson (History)

    Jochen:
    The Saturn 5 trajectory was optimized for low earth orbit injection, followed by a coast phase before trans-lunar injection.
    The Saturn C-1 had a burnout angle of 24 degrees (velocity 2.65 km/sec).
    The Atlas E (satellite launch configuration) had a first stage burnout angle of 26 degrees (velocity 2.6 km/sec).
    The Proton rocket has a first stage burnout angle of about 25 degrees (velocity 1.65 km/sec). The Space Shuttle has a first stage burnout angle of 31 degrees (velocity 1.3 km/sec).
    The Rockot launch vehicle is a converted ballistic missile, but there’s no reason why it should fly a ballistic missile trajectory.

  15. Jochen Schischka (History)

    To David Wright:

    You are right, clustering of engines is not as complicated as generally presumed (although there are issues like simultaneous ignition or uniform thrust-levels on all chambers to consider); Even the Iraqis managed to accomplish that in 1989 (-> Al-Abid), almost without any technological expertise in that department.

    The real problem is designing and constructing a new-diametered body without any experience in that sector (i think the Chinese had russian help – they trained the chinese engineers, didn’t they?) and/or specifically adapted tooling.

    Let’s get surprised by what kind of rabbit the North Koreans will draw out of the hat in the end…

    (BTW, Geoff: I agree with you, 1.) we can’t be 100% sure of anything in this context and 2.) it is advisable to stay open-minded until we have access to hard evidence verifying/falsifying one theory or the other.)

  16. David Wright (History)

    I agree that North Korea may surprise us. So in my paper I basically look at things in two steps. First, I use the China LM-1 as sort of a real-world upper bound for what an early version of a launcher of this size would look like, and that is consistent with a straightforward evolution of the kind of technology North Korea has used in the past. That gives a relatively short range as a ballisitic missile.

    Second, I look at the kinds of things that countries have typically done to improve the capability of launchers and therefore the range of missiles, and in that case you could get a true ICBM.

    I agree that we don’t know where NK is along that continuum. I read your post as saying that you were actually expecting a pretty capable missile, as opposed to saying it is possible. It sounds like we all need to be careful to make clear the range of possibilities and the ambiguity in what we actually know.

    On the issue of building a larger missile body to accommodate clustered engines: The same Chinese engineer I noted above told me that when they decided to build the DF-3, China did not have the machine tools to build a cylinder with a diameter of 2.25 m, and that that was a significant problem they had to solve. Similarly, he said that designing and manufacturing the jet vanes was much more complicated than they expected, and contniued to be a challenge when they modified the boosters to increase the thrust and change propellants. So it is certainly worth remembering that factors that may seem somewhat mundane can be important technical challenges in actually building a missile.

  17. Geoff Forden (History)

    David,
    The post is titled “First Guesses…” and in the first comment (to try to emphasize the extent that we are dealing with an unknown) I say we don’t even know if it is going to have a large first stage as opposed to a Safir-type satellite launch. Peter Brown even pointed out that the current understanding is that the North Koreans might not have even started assembling the rocket. (Perhaps there are political reasons for that: perhaps they want to be able to quickly stop the launch. There could also be military reasons: they don’t want to expose their rocket to attack as some people suggested in 2006.) I also said that other people’s models (your’s among others) would be higher fidelity, which means they would be based on more “realistic” assessments.

  18. Geoff Forden (History)

    The missing pieces of information are the satellite’s orbit and its mass. Hopefully, if the satellite mass is as large as I suspect it will be, the North Korean’s will be as open as the Iranians were and its mass will be known. Given the satellite’s mass and the orbital altitudes, we can constrain the second stage mass fractions etc. with the splash down zones.

  19. V.S. (History)

    Geoff and anyone else that might know,

    A question. Sorry if its silly or naive but I’m a social sciences dude.

    Could we say that there are different “schools” of rocket launching? Like an “American” and a “Russian” way/technique/approach? If yes I’d guess that Norks use the latter.

    Physics is physics and math is math regardless of political affiliation, but then again, who knows.

    Could you please answer that, or is there a posting of yours that I’ve missed and could you direct me accordingly?

    Thanks in advance.

  20. Geoff Forden (History)

    V.S.—
    Thats an interesting question and Im sure others who comment on rockets/missiles will also add to (or contradict) my answer but let me take a stab at it.

    First, there are obvious differences in technologies and those technologies have shaped some of the choices the two “sides” have taken. Im more familiar with the differences in Russian and US early warning satellites and how they have influenced the doctrines both countries have followed but there are also differences in missile technology. For instance, Russia early on developed powerful rocket engines and used that power in their designs while it seems like the US had a harder time developing the more powerful engines and placed more of an emphasis on shaving off the maximum dead weight to its missiles.

    But there is certainly a difference in engineering between the two countries that goes to something deeper. Its been my experience in working with international collaborations that included both Russian engineers and American engineers that the Russians were more “hands on.” The example Im thinking of involved both countries manufacturing rather heavy devices that required precision positioning of plates of steel 2 inches thick. The US spent a considerable amount of time designing (“engineering”) these things so that they would be manufactured to the precise spacing. The Russians, on the other hand, rather quickly assembled them and then went through and “wacked” them until they had the correct spacing. Both methods seemed to work though the Americans were very concerned about any weakening this production technique might have introduced. (This was about 15 years ago and I think there has not been any problem since even though they have been in constant use since then.)

    I agree with you that the North Koreans would more likely follow the Russian model in engineering their rockets/missiles. But we should be able use the principles of physics to infer what they have done once we have enough information; I don’t believe though that we are there yet.

  21. V.S. (History)

    Thanks Geoff.

  22. Peter J. Brown (History)

    Can we get confirmation that missile assembly is actually underway, please?

    Korea Times is now reporting the following —

    Two US Aegis Ships Ready to Intercept N. Korean Missile
    By Lee Tae-hoon
    Staff Reporter

    http://www.koreatimes.co.kr/www/news/nation/2009/03/116_41715.html

    Two U.S. Aegis-equipped destroyers will detect and trace North Korea’s long-range missile to be launched between April 4 and 8, Yonhap News Agency reported Sunday.

    USS John S. McCain and another U.S. Aegis destroyer that participated in the large-scale South Korea-U.S. Key Resolve exercise remain in the East Sea in response to the North’s upcoming missile launch, a military source was quoted as telling Yonhap.

    The 12-day command-post exercise, which involved 14,000 U.S. troops stationed outside the peninsula, ended Friday.

    The two U.S. warships are ready to intercept what the Stalinist North claims a satellite if it is deemed to pose a threat, the source said.

    Korean-American officer Jeffrey Kim commands the USS John S. McCain, whose four radars can detect any object within a radius of 1,000 kilometers, he said.

    The 9,200-ton destroyer is also capable of shooting down the North’s rocket with its SM-3 interceptor missiles, according to the source.

    The SM-3s can fly at a speed of 9,600 kilometers per hour and hit missiles at up to 160 kilometers above the sea level.

    Japan has also deployed its two Aegis destroyers equipped with SM-3 missiles in the East Sea ahead of the North’s missile launch, sources said.

    leeth@koreatimes.co.kr

    Is a US shootdown a sensible solution? By allowing NK to follow through with this — let alone fire it directly at Japan — is it tantamount to allowing the entire East Asian security agenda to vaporize with repercussions too volatile to imagine? How dangerous is NK going to be allowed to become, and is NK going to be more stable, more rational and more responsible about its role in the world 3 years from now?

    Is China apparently dropping the ball entirely here? We need answers to these questions by the end of this week.

  23. Josh

    Peter:

    According to the Korea Times story you cite, all four Aegis cruisers in the region are stationed in the Sea of Japan (East Sea). Because they have no known capability to attack a rocket as it boosts, this is largely a symbolic gesture.

    If an object were to fall from space towards Japan, of course, the Aegis boats would be in a position to attempt an intercept. But if the launch is conducted as North Korea has described it, the only thing falling will be expended rocket stages, and this will take place over water.

  24. Peter J. Brown (History)

    I don’t know if both Japanese ships are cruisers — Kongo is for sure. At the same time, recall that comments in the press from the Pentagon and Tokyo lately drew the heated response from Pyongyang to the effect that any interception would trigger a devastating attack on the offending party. Does NK see a shootdown as feasible when everyone else does not? They can do the math, too. You may be right about a “symbolic gesture” but only time will tell. Regardless, I am still waiting for an assembly status update.

  25. Rwendland (History)

    Can anyone say at what altitude the DPRK rocket should pass over Japan, and if that is “in space”? (100km?)

    It would be interesting to see a risk analysis of accidental impact on Japan compared to other launches, say a Shavit launch from Israel which also sends a 2nd stage over other states before splashdown in the Atlantic. I don’t have the launch track for a Shavit, but the 2nd stage probably goes over about 1600km of low-population density North Africa about 2250km after launch. (Alternatively about 800km of Sicily, Spain and Portugal perhaps, or 950km of higher-population density coastal Africa.)

    This compares to the DPRK 2nd stage which goes over about 160km of Japan 880km after launch.

    Unless the DPRK accidental impact risks are significantly greater, I doubt it is easy to justify criticism on that basis.

  26. Peter J. Brown (History)

    For everyone trying to stay on top of the latest round of the Asia missile defense fact or fiction debate — for lack of a better tag – check this out. Where are we difting here, onto the rocks by chance?

    “Officials dispute Japan’s supposed inability to hit N Korean rocket”

    Tuesday 24th March, 01:06 PM JST

    http://www.japantoday.com/category/politics/view/japan-unable-to-intercept-n-korea-rocket-senior-govt-source

    TOKYO —

    Defense Minister Yasukazu Hamada disputed a claim Tuesday made by a senior government source a day earlier that Japan would be unable to intercept a rocket North Korea plans to launch. ‘‘I don’t think that will be the case because we have been trying to be well prepared,’’ Hamada said.

    At a news conference the same day, Chief Cabinet Secretary Takeo Kawamura said he is not worried about the country’s ability to intercept the projectile, which Japan and other countries see as cover for a ballistic missile test.

    ‘‘I don’t have any such concern because the government has taken steps to respond to the matter well,’’ Kawamura said, adding that Tokyo has taken every possible scenario into account to ensure the Japanese people’s safety. ‘‘We are at the final stage of reviewing (options) right now.’’

    Several lawmakers of the ruling Liberal Democratic Party also expressed displeasure over the remark at a meeting Tuesday morning.

    In a remark made Monday on condition of anonymity, the senior government source said, ‘‘You cannot shoot down a pistol bullet with a pistol,’’ suggesting that Japan’s antiballistic missile shield may be incapable of intercepting the rocket.

    The source said a Standard Missile-3 interceptor launched from a Maritime Self-Defense Force destroyer succeeded in intercepting a mock target before because the MSDF was notified of the launch beforehand.

    The rocket, which Pyongyang says it plans to launch between April 4 and 8 to put a satellite into orbit, is expected to fly over the Tohoku region in northeastern Japan if it travels as planned.

    Its two-stage boosters are believed to fall into the two ‘‘dangers’’ areas North Korea has marked in the Sea of Japan off Akita Prefecture and in the northern Pacific between Japan and Hawaii.

    Japan is permitted to intercept a ballistic missile or similar objects, including a satellite-carrying rocket, based on provisions in the Self-Defense Forces Law if it is feared to fall onto Japanese soil or waters and inflict damage to people’s lives and property.

    The SM-3, which intercepts an incoming missile outside the earth’s atmosphere, forms the upper layer of Japan’s missile shield, while the Air Self-Defense Force’s Patriot Advanced Capability-3 system, which is supposed to hit missiles the SM-3 misses, is responsible for the lower layer.

    Two MSDF Aegis destroyers have been modified to be fitted with the SM-3. The MSDF has performed interception tests with the destroyers, with one success and one failure. The ASDF’s PAC-3 succeeded in intercepting a target in a test in September 2008.

    Kyodo News (subscription required) is also running this story now —

    Mar.24 18:48 China signals concern about Japan’s plan to intercept rocket

    So, is this some sort of distorted regionwide disinformation campaign or what? Does the capability exist or not, and if not, why is this spinning almost out of control?

  27. Josh

    Peter:

    This is a war of words. If the Aegis boats are in the Sea of Japan — which is the right place to be to actually, you know, defend Japan — there should be nothing for SM-3 to shoot at. As noted in the story you quote, the SM-3 is a midcourse interceptor, not a boost phase interceptor. As you can see in Geoff’s illustration, the plan is for Unha-2 to boost all the way over Japan.

    Now, either Japan or America could still use force against the booster or the satellite. But given the limits of currently deployed technology, they’d have to attack the booster on the ground, or they’d have to move an Aegis boat out into the Pacific to perform a midcourse intercept of the satellite itself, at which point we are no longer talking about the defense of Japan, are we?

    Either one of these ideas would be really bad, in its own way.

    Richard:

    I’m not sure where to look for authoritative information, but was under the impression that the Shavit goes over the Strait of Gibraltar.

  28. Peter J. Brown (History)

    Now that Japan has won the World Baseball Championships, all bets are off.

    Josh, based on this ongoing stream of very public comments by Japanese officials in particular, apparently Tokyo is not paying attention to what you have been saying. Or maybe they know something that we don’t.

    Anyway, according to Mike Shuster at NPR — “U.S. Wary Over Planned N. Korean Rocket Launch” —

    “Still, uncertainties persist. The North Koreans are assembling the rocket inside a long covered building, out of sight. They will disassemble it, bring the parts out to the launch pad, and reassemble it there. Erecting the rocket on the launch pad will take three days, and it will take another two days to fill it with liquid fuel.”

    http://www.npr.org/templates/story/story.php?storyId=102265046&ft=1&f=1003

  29. Josh

    Peter:

    Actually, I see nothing in the recent comments of Japanese officials that’s inconsistent with what I’ve written. For example:

    Japan is permitted to intercept a ballistic missile or similar objects, including a satellite-carrying rocket, based on provisions in the Self-Defense Forces Law if it is feared to fall onto Japanese soil or waters and inflict damage to people’s lives and property.

    This legal analysis also happens to line up with what’s technically possible. And with NK long-range rocket technology, truth be told, you never really know where things are going to fall out of the sky, regardless of what the North Koreans have planned!

  30. Peter J. Brown (History)

    I am just an observer here, and I am quite aware that we are all hindered by English
    translations that can often stray off course.

    “But given the limits of currently deployed technology, they’d have to attack the booster on the ground, or they’d have to move an Aegis boat out into the Pacific to perform a midcourse intercept of the satellite itself, at which point we are no longer talking about the defense of Japan, are we?”

    OK. However, take another look at the Kyodo News headline I mentioned a moment ago — Mar.24 18:48 “China signals concern about Japan’s plan to intercept rocket”

    China does not care if Japan or the US has plans to protect civilian populations in Japan from debris resulting from some out of control test. Here, the headline says nothing about the payload, but refers specifically to the launch vehicle.
    I wonder if Japan informed China two weeks ago at a meeting in China that Japan could not and would not accept a ballistic missile disguised as a satellite launcher fired by NK right over Japan. Just speculation.

  31. Rwendland (History)

    Josh,

    Re Shavit launch trajectory. A few non-authoritative sources do say over the Strait of Gibraltar. But to get there without mid-course corrections seems to take you over about 900km of Africa, fairly close to Malta, Tunis and Algiers. Such a route quite possibly has an accidental impact risk to people higher than the DPRK launch track – for first launches anyway. And Algiers wasn’t given SM-3 protection against a 2nd stage failure! Hopefully in both cases the risks are extremely low.

  32. Peter J. Brown (History)

    Here is a news report that I held off on earlier because I am still not able to verify this independently. Can anyone else verify this dclaration by China? Otherwise, it is very significant. One reason there is no mention of this in China’s English language press, for example, may stem from sensitivity surrounding the fact that DPRK Premier Kim Yong Il arrived in China last week just days before Japanese Defense Minister Yasukazu Hamada’s visit to China.

    Monday, March 23, 2009

    “All major powers have aircraft carrier except China: Chinese Defense Minister”

    http://theasiandefence.blogspot.com/2009/03/all-major-powers-have-aircraft-carrier.html

    “Chinese Defense Minister Liang Guanglie urged North Korea not to go ahead with a proposed satellite launch during a meeting with his Japanese counterpart here on Friday, the first time Beijing has overtly demanded Pyongyang back down from a rocket launch.”

    “It was the first time in five and a half years that a top Japanese defense official has visited China, since the then Defense Agency chief Shigeru Ishiba’s visit in September 2003. In August 2007, then Chinese Defense Minister Cao Gangchuan visited Japan to meet his counterpart at the time, Masahiko Komura.”

  33. Peter J. Brown (History)

    N Korea ‘places missile on pad’ according to BBC

    http://news.bbc.co.uk/2/hi/asia-pacific/7964364.stm