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#220 by Kryten on 10 Aug, 2017 08:14
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We know HS-13 used a 4D10 cluster, we've seen images of the back end of the missile. But the HS-14 clearly does not use the same engine.
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#221 by Danderman on 10 Aug, 2017 21:17
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If we assume that HS12 uses the same engine as HS10, with 2 extra verniers, and HS13 uses 2 4D10s in a cluster, if HS14 doesn't use a 4D10 derivative in its first stage, in other words, if it were to use an RD-250 derived engine, that would truly be a lot of rocket engine development work to produce multiple engines in the same class.
Since the clustered 4D10s are alleged to produce 80 tons of thruster, the NK version of the 4D10 therefore would produce 40 tons (presumably including the verniers), which would be sufficient for HS12 and HS14. -
#222 by hop on 11 Aug, 2017 04:20
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#223 by Danderman on 11 Aug, 2017 04:56
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https://documents-dds-ny.un.org/doc/UNDOC/GEN/N17/024/94/PDF/N1702494.pdf
Link seems to be broken.
http://www.un.org/ga/search/viewm_doc.asp?symbol=S/2017/150
This is the primary link, from which you can choose the document language.
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#224 by Chasm on 11 Aug, 2017 15:54
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Don't assume, look at the launch pictures.
The HS-12 does not use the same engine as the HS-10.
HS-12 and HS-14 use the same or at least very similar engines.
The nozzle of the HS-12 and HS14 first stage is of the same size and visibly larger than the HS-10.
The UN document is from February 2017, a lot has happend since.
As far as the disco ball goes, here is what it says:Quote11. On 9 March 2016, state media announced that Kim Jong Un had inspected a spherically shaped object and been briefed on “specifications and the mechanism of the miniaturized powerful nuclear warheads with a Korean-style structure of mixed charge” (see figure 3). The report claimed that “the nuclear warheads [have] been standardized to be fit for ballistic rockets”.15 According to a Member State, the device lacks the physical characteristics typically associated with a thermonuclear device,16 and its plates, which can be seen on the surface, do not hide explosive lenses.17
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15 “Kim Jong Un guides work for mounting nuclear warheads on ballistic rockets”, Rodong Sinmun, 9 March 2016.
16 A standard thermonuclear device features two stages, not featured in the Democratic People’s Republic of Korea device.
17 Distributing explosive lenses on the surface at regular intervals may achieve a higher degree of implosion symmetry and, hence, higher yield.
Not a thermonuclear device.
Not using a specific method to increase yield.
The takeaway is as usual hidden between the lines: Nobody says that it's not a fission device...
Taking another look at the disco ball propaganda picture, open source experts said it
- is staged in all aspects to convey a message, esp. Kims clothing
- is likely supposed to show their "standardized, compact" design
- is small enough to fit into NK reentry vehicles
- calculates to a weight that is light enough for NK missiles
- conveys a design that is feasible
Which is good enough for me. The UN report did not contradict any of that and actual nuclear weapons designers are not commenting openly.
Is it the real thing? Or at least a representation of the real thing? - We don't know.
We can't know short of sending experts to take it apart and give us an report. [Not going to happen, ever.]
We however do know that shorty after the picture NK did their 5th nuclear test.
Taking all of that into account it becomes clear why the other major concern of open source experts is that NK is talking more and more about a large, heavy device instead of their compact weapon. Chances are that test 5 was indeed a boosted weapon and it finally works. Is the next one a true thermonuclear design? If so that would increase the tensions drastically. -
#225 by Danderman on 11 Aug, 2017 16:26
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I admit that discussions of nuclear weapons are beyond me, other than noting that NK claimed to test a thermonuclear weapon last year, and no one believes them.
I agree that HS10 and HS12 do not use the same engine, since they differ in the number of verniers, 2 vs 4. Both seem to use an R-27 derived main engine.
Here is an analysis of HS12 that concurs with my assessment:
http://www.38north.org/2017/05/hwasong051917/
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#226 by catdlr on 12 Aug, 2017 05:14
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North Korea’s “not quite” ICBM can’t hit the lower 48 states
Massachusetts Institute of Technology rocket expert Ted Postol and two German experts, Markus Schiller and Robert Schmucker of Schmucker Technologie, published their findings Friday in the Bulletin of the Atomic Scientists:
http://thebulletin.org/north-korea%E2%80%99s-%E2%80%9Cnot-quite%E2%80%9D-icbm-can%E2%80%99t-hit-lower-48-states11012Quotethe North Korean rocket fired twice last month—the Hwasong-14—is a “sub-level” ICBM that will not be able to deliver nuclear warheads to the continental United States. Our analysis shows that the current variant of the Hwasong-14 may not even be capable of delivering a first-generation nuclear warhead to Anchorage, Alaska, although such a possibility cannot be categorically ruled out. But even if North Korea is now capable of fabricating a relatively light-weight, “miniaturized” atomic bomb that can survive the extreme reentry environments of long-range rocket delivery, it will, with certainty, not be able to deliver such an atomic bomb to the lower 48 states of the United States with the rocket tested on July 3 and July 28.
QuoteGeneral conclusions—for now. Our general conclusions from intensive study of a wide variety of data relating to the two rockets that North Korea launched in July:
The Hwasong-14 does not currently constitute a nuclear threat to the lower 48 states of the United States.
The flight tests on July 4 and 28 were a carefully choreographed deception by North Korea to create a false impression that the Hwasong-14 is a near-ICBM that poses a nuclear threat to the continental US.
The Hwasong-14 tested on July 4 and 28 may not even be able to deliver a North Korean atomic bomb to Anchorage, Alaska.
Although it is clear that North Korea is not capable of manufacturing sophisticated rocket components, their skill and ingenuity in using Soviet rocket motor components has grown very substantially. This is not good news for the long run.
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#227 by Websorber on 12 Aug, 2017 10:18
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High Levels of Activity at North Korea’s Sinpo South Shipyard
http://www.38north.org/2017/08/sinpo081117/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+38North+%2838+North%3A+Informed+Analysis+of+North+Korea%29
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#228 by Chasm on 12 Aug, 2017 12:24
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North Korea’s “not quite” ICBM can’t hit the lower 48 states
Massachusetts Institute of Technology rocket expert Ted Postol and two German experts, Markus Schiller and Robert Schmucker of Schmucker Technologie, published their findings Friday in the Bulletin of the Atomic Scientists:
http://thebulletin.org/north-korea%E2%80%99s-%E2%80%9Cnot-quite%E2%80%9D-icbm-can%E2%80%99t-hit-lower-48-states11012
Hm. Less of rocket than others think, larger device than others think. The cherry on top is that Norbert Brügge is once more impressed by their ability to use his original research without any mention and getting away with it.
This time he even predicted it. -
#229 by RotoSequence on 12 Aug, 2017 21:06
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North Korea’s “not quite” ICBM can’t hit the lower 48 states
Massachusetts Institute of Technology rocket expert Ted Postol and two German experts, Markus Schiller and Robert Schmucker of Schmucker Technologie, published their findings Friday in the Bulletin of the Atomic Scientists:
http://thebulletin.org/north-korea%E2%80%99s-%E2%80%9Cnot-quite%E2%80%9D-icbm-can%E2%80%99t-hit-lower-48-states11012
Hm. Less of rocket than others think, larger device than others think. The cherry on top is that Norbert Brügge is once more impressed by their ability to use his original research without any mention and getting away with it.
This time he even predicted it.
Norbert Brügge? -
#230 by Danderman on 13 Aug, 2017 00:49
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Assuming the thrust of the upper stage is 3,000 kg, and ISP is 300 seconds, if the stage burned for 244 seconds, that works out to 2440 kg of consumed propellant. This does not count the mass of the tanks and engines and nosecone, let alone a payload. In short, if the stage contained a payload anywhere close to 500 kg, it could not have itself provided much altitude to the flight, given the steep trajectory.
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#231 by Danderman on 13 Aug, 2017 00:59
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Another way of looking at the upper stage is by assessing how much propellant it could carry. Assuming a diameter of 1.4 meters and a length of 2.5 meters, that is a volume of just under 4 cubic meters. Since the density of rocket fuel is higher than water, if the entire volume of the cylinder were a single tank, it could carry some 5 or 6 tons. However, it is a bipropellant, so some of the volume is used by at least one bulkhead, as well as the rocket engines and any gas tanks, avionics, cabling. So, around 2500 kg of prop is a reasonable estimate, maybe more if the engines are submerged.
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#232 by Chasm on 13 Aug, 2017 01:13
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Norbert Brügge?
The person behind b14643.de. A geologist in real life, writing extensively about space launch vehicles and other things rocket like the NK missiles. Writing quite a bit about geology too.
He is the only one, that I know about, who did a full revision of his rocket analysis for all NK rockets after the concert image dump - and published his revised analysis for all of them including comparisons.
The armscontrolwonks / CNS / NTI did revisions of their models but little publication thereof so far.
Every analyst has his or her own bias. When they are from the same person/group and time frame it is much easier to compare between them.
He was likely the first to write that in his opinion NK uses a variant of the RD-250 series engines. Something that, months later, the writers of the white paper pass off as their own original research.
Here is an archived version of the HS-14 page where he wondered who else will use his work without cite, naming the Washington post. Archived version of the page today after the MIT paper. (For unknown values of MIT, but it is called that in German media.) -
#233 by Danderman on 13 Aug, 2017 07:18
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There is a lot of handwaving in the linked article. For example, just because numbers are given for engine performance doesn't mean anything if there is no sourcing for those numbers. More to the point, numbers with decimal points seem impressive, but at best, these are rough guesses, so the implied precision does not exist.
As to the claim that NK has plans for the "RD-250" engine, first off, although the engine can produce 80 tons of thrust, that is with 2 Chambers, not one. Anyone claiming that they know the thrust of a single chambered version with any precision would have to be North Korean, if they have produced such an engine.
However, the claim that EnergoMash engineers provided RD-250 tech to NK is truly bizarre, since the engine has been out of production for so long. It is more likely that the tech came from Ukraine, but no one is making that claim. -
#234 by WulfTheSaxon on 14 Aug, 2017 16:17
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It is more likely that the tech came from Ukraine, but no one is making that claim.
https://www.nytimes.com/2017/08/14/world/asia/north-korea-missiles-ukraine-factory.html -
#235 by Star One on 14 Aug, 2017 21:10
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Here's the original report.
http://www.iiss.org/en/iiss%20voices/blogsections/iiss-voices-2017-adeb/august-2b48/north-korea-icbm-success-3abb
I wonder how easy they will find it to cluster the RD-250s on the first stage and could it be used on the second stage as well? -
#236 by russianhalo117 on 14 Aug, 2017 21:39
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Here's the original report.
Original RD-250 is 4 nozzle design with shared turbopump et cetera, so all that I can see is them going to the original design as 1, 2, 3 nozzle variant would be solely domestic in design and manufacture which require high quality craftsmanship which they do not have a good record of. It could that RD-250 is incorrect and that its another Soviet era engine.
http://www.iiss.org/en/iiss%20voices/blogsections/iiss-voices-2017-adeb/august-2b48/north-korea-icbm-success-3abb
I wonder how easy they will find it to cluster the RD-250s on the first stage and could it be used on the second stage as well? -
#237 by Star One on 14 Aug, 2017 21:42
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Here's the original report.
Original RD-250 is 4 combustion chamber design with shared turbopumps et cetera, so all that I can see is them going to the original design as 1, 2, 3 chamber variant would be solely domestic in design and manufacture which require high quality craftsmanship which they do not have a good record of. It could that RD-250 is incorrect and that its another Soviet era engine.
http://www.iiss.org/en/iiss%20voices/blogsections/iiss-voices-2017-adeb/august-2b48/north-korea-icbm-success-3abb
I wonder how easy they will find it to cluster the RD-250s on the first stage and could it be used on the second stage as well?
The article indicates no other engine matches the description/images of that used? -
#238 by Chasm on 14 Aug, 2017 22:56
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4 nozzles per tubo pump?
The RD-250 family engines in question have 2 nozzles and 1 turbo pump. Propellant is N2O4/UDMH
RD-250 (8D518), 3 form a RD-251 -> R-36aka SS-18 Satanaka SS-9 Scarp
RD-250PM, 3 form a RD-261 -> Tsyklon-2 and -3
Upper stage versions also have 2 nozzles and 1 turbo pump.
RD-252 (8D724) -> R-36aka SS-18 Satanaka SS-9 Scarp
RD-262 (11D26) -> Tsyklon-2 and -3
RD-253 as used on the Proton is not part of the discussion.
The previous generation of engines ~7 years older is the RD-215 family. Propellant is AK-27/UDMH
RD-215 (8D513) 2 form a RD-216 -> R-14 aka SS-5 Skean
An updated version of is the RD-215M / RD-216M was used on the Kosmos-3M space launcher, 444 launches last launch in 2009
Others in the series also have 2 nozzles and 1 turbopump
RD-217 (8D515), 3 form a RD-218 -> R-16 aka SS-7 Saddler
RD-225 (8D721), 3 form a RD-224 -> R-26 (not deployed)
The upper stage version has 2 nozzle 1 tubopump
RD-219 (8D713) -> R-16
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I think that it is entirely possible that NK managed to find and import a few of these engines in the last ~30 years. Not as complete rockets or even new old stock engines but likely as scrap. After all how well were used first stages policed, how much attention is paid to the scrapyards after that?
The hard part is supposed to be turbomachinery and metallurgy. Both are not too hard to get close to with enough scrap and a modern metallurgy lab. If they indeed bought them together with other arms in the mid 1990s the would have had 20 years to get a copy working. Not impossible certainly not as analytical instruments got better.
EDIT:
Ooops. Copy and paste is hard.
R-36 aka SS-9 Scarp
R-36M aka SS-18 Satan
4 RD-263 (1 pump per nozzle) form 1 RD-264 as used on the R-36M first stage. -
#239 by Websorber on 15 Aug, 2017 10:29
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KJU Inspects KPA Strategic Force The Movie
