A rchive Date
[ 07-01-2003 ]
Category
[ International Relations ]
sub-Categoy
[ North Korea ]
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[http://www.fas.org/nuke/guide/dprk/missile/nd-1.htm
North Korean Missiles
Nodong
A more extensive redesign of the Scud technology may have begun in the same 1988 time-frame as the modification program that resulted in the Scud-C. The new missile [variously called No-dong-1, Ro-dong 1, and Scud-D has a potential range/payload capacity of 1,000-1,300 km/700-1,000 kg. The higher range would cover a wide swath of cities from Tokyo to Taipei. At the extremity of the higher range, authoritative analyst estimates the CEP of the No-dong to be 2,000-4,000 m.
A prototype was detected on a launch pad in May 1990. Test flights did not begin until May 29-30, 1993, with an apparently successful launch 500 km into the Sea of Japan. This flight test of the No-dong-1 was almost certainly a high altitude flight with warhead separation being demonstrated. All within the 500 kilometer SCUD-C/D range profile. That is, the No-dong-1 rose to a much higher altitude with in a 500 kilometer range. Propulsion tests began in August 1994. To date the flight test program has consisted of this single North Korean test to partial range, along with what were apparently two tests by Pakistan and three by Iran [only one of which was completely successful]. As of late 2000 the US Department of Defense reported that North Korea continued to make and field No Dong missiles able to strike American forces based in Japan.
The No-dong program has evidently been plagued by numerous technical and financial problems. Some authoritative observers expected the first production models of the No-dong to be available in 1997, with export shipments soon thereafter. However, the CIA did not expect the No-dong to be deployed until the end of 1996. Reflecting the difficulties of assessing the precise status of the program, at a News Briefing on 09 July 1998 Secretary of Defense William Cohen states that "What we can say is that North Korea has completed its development of the No-dong missile, but I am not in a position to comment in terms of when or where or how there has been a deployment of the missile itself."
The operational status of the No-dong design remains unclear. Operational training for crews may have begun in mid-1995. Missile storage facility construction began in July 1995, and as many as four launch sites were reportedly complete by October 1995. Mobile launchers were reportedly deployed in northeast North Korea in March 1997, and seven launchers were also deployed at a facility about 100 kilometers from Pyongyang.
The 1998 Rumsfeld report concluded that the "Commission judges that the No-dong was operationally deployed long before the U.S. Government recognized that fact. There is ample evidence that North Korea has created a sizable missile production infrastructure, and therefore it is highly likely that considerable numbers of No-dong's have been produced." One of the unclassified discussion papers generated in the preparation of the Rumsfeld report indicated that only a small number of the systems (ten mobile launchers with missiles) have been produced by North Korea and fielded with its own forces ["Iran and Iraq" Michael Eisenstadt, Kenneth Katzman, Kenneth Timmerman and Seth Carus - March 23, 1998]. According to an ROK military source, the DPRK had deployed at least nine No-Dong 1 missiles by early 1999, in addition to the Scud-A, Scud-B, and Scud-C missiles. Japanese sources suggest that 15-100 missiles are currently deployed.
The No-dong represent a significant departure from the prior North Korean practice of incremental improvements on the basic single-engine Scud design, and this departure is reflected in the protracted development history of the system, This single-stage missile apparently incorporates a SS-N-4, Isayev S-2.713M engine with a single large combustion chamber. The closely related Iranian Shehab-3 and the Pakistani Ghauri-II do reflect this design.
Some aspects of the No-dong seems to bear a close design resemblance to the early Soviet SS-N-4/R-13 and SS-N-5/R-21 SLBM designs. This would not be to surprising, given that these early submarine-launched ballistic missiles were an evolutionary development of the same Scud technology that is used by North Korea.
The Soviet R-13, known in the West as the SS-N-4, used one Isayev S2.713 engine with larger 1.3 m diameter tankage from the Scud 0.88 m diameter tankage design and warhead separation from the missile body. This missile had a launch weight of 13,745 kg, a range of 600 km and a body diameter of 1.3 meters. And the R-21, designated the SS-N-5 used the 4 thrust chamber Isayev S-5.38 higher thrust engine and more tankage with perhaps a material change and rearranged propellant tanks along with warhead separation. With a body diameter of 1.4 m, this missile had a launch mass of nearly 19,653 kg. with a range of 1,420 km.
The No-dong has a reported mass of 15,200-16,000 kilograms, with a diameter of 1.32-1.35 m's and a length of 15.895 m giving it a range of 1,350-1,500 km's. The characteristics of the No-dong missile with its 15,852-16,852 kg launch weight (with a 760-1,000 kg warhead) falls right in between the two older Soviet SLBM's design. While this may simply reflect the unavoidable consequence of using this proven Scud design approach to achieve a long range missile, other evidence suggest that a more direct connection may exist.
In October 1992, the Russian, Security Minister stopped more than 60 Russian missile specialists at Moscow's Sheremetyevo-2 airport where they were preparing to leave for North Korea, and subsequently a North Korean Major General was declared persona-non grata by the Yeltsin government. It turned out that these technical personnel were from the V.P. Makayev OKB, the submarine ballistic missile design bureau. It is difficult to assess the full extent of collaboration and technology transfer between the Makayev bureau and North Korea during this Gorbachev era, although such a large, senior delegation almost certainly meant that an earlier contact had already been substantially completed with certain critical documentation exchanged as a part of an agreement.
The SS-N-4 and SS-N-5 have been on public display at the Russian Central Army Museum since at least 1992. The existence of these missile demonstrates that this is a potential fruitful line of development to extend the range of Scud-derived systems. It certainly represents a proven design concept, in contrast to the less sophisticated Iraqi approach of simply clustering multiple Scuds to achieve longer range. But the apparent slow and uneven progress on the No-dong program since 1992 may not be entirely unrelated to the cessation of active assistance from Russian sources
Soviet Design Path of Their First SLBM's
R-13/SS-N-4
The R-13/SS-N-4 used one Isayev engines S2.713 with larger tankage from the Scud design and warhead separation from the missile body. The propellant tanks were rearranged. This was done for center of gravity control of the launch vehicle. This duel drain points were also used in the R-13/SS-N-4 tankage arrangement to assist that center of gravity control according to Makayev OKB historic documents. Deployed 1960
R-21/SS-N-5
The R-21/SS-N-5 used four Scud type thrust chambers to create an advanced higher thrust Isayev engine S5.38 and more tankage was added with a possible material change as well as warhead separation. Deployed 1963.
While there is little doubt that the No-dong is of North Korean design and manufacture, it certainly seems to have benefitted from some aspects of the Makayev SLBM program experience and design details. The source of this missile technology transfer is the cancellation of the Soviet liquid fueled SLBM programs in the early 1980's. By the mid 1980's the liquid SLBM's program personnel were reduced to caretaker status for deployed existing hardware. Effectively the cancellation of the programs resulted in the unemployment for a large group of highly trained rocket personnel. In an effort to re-employ their personnel, Glavkosmos of the Ministry of General Machine building tried to market these SLBM's commercially as satellite launchers. The effort failed. The formal technology exchange between the Russians and the North Koreans probably started in 1988, well before the 1991 collapse of the USSR. How much technology and materials expertise was transferred, if any remains unclear. But the slow pace of this program suggest that some combination of technical and resource constraints have sorely challenged the North Korean missile program.
How did the North Koreans develop No-dong?
The Scud mods A, B, C, and ND-1 & 2 experience is very similiar to that experienced by the Soviets with its ScudA derived SLBMs and Scud-B program which is almost certainly no coincidence.
Developing Nations and Warhead Dynamic Performance
Recently, it was suggested that the developing nations missile program warheads would be tumbling about their center of gravity during re-entry, which would then make it difficult to identify. This was because they were not being spun-up along their longitudinal axis prior to re-entry through the atmosphere.
A warhead is much like a bullet fired from a rifle barrel. If the barrel is grooved to spin up the bullet along its longitudinal axis it tends to fly through the atmosphere to its target more smoothly and accurately. If the barrel is not built with this capability, the bullet tumbles uncontrollably about its center of gravity throughout its flight in the atmosphere to its target. This tumbling reduces the accuracy of the projectile.
This kind of missile warhead tumbling was noted in the ballistic flights of Iraqi's Scud-B, Scud-C/Al-Hussein, Scud-D/Al-Abbas ballistic missiles during the Gulf war. In this particular case all of the warheads remained attached to the Scud derived rocket bodies. The length of the Scud-C and D missile bodies and the failure to spin up either the missile with its warhead or separate the warhead after missile spin up made them extremely unstable and in accurate during re-entry to their target.
Today this is not the case with North Korean derived warhead technology. North Korea successfully demonstrated payload spin up with the satellite launch attempt of the Taep'o-dong-1 or PAEUTUSAN-1 booster. The Paeutusan-1 solid propellant third stage both demonstrated a near full duration burn and the spin up of the stage and satellite along its longitudinal axis. However, the third stage solid motor ruptured, de-orbiting the satellite, almost immediately after achieving orbital velocity.
Therefore, it would be correct to assume that besides North Korea's, No-dong (first stage of Taep'o-dong-1), both Pakistan's Ghauri-II and Iran's Shahab-3 all benefit from this spin-up technology. The Shahab-3/Ghauri-II both apparently spin up the single booster stage and warhead combination starting at about 10 seconds before the termination of the powered flight at 110 seconds. At this point after 110 seconds of powered flight the warhead is then separated from the booster stage to fly on a re-entry trajectory that remains stable to its target. With the addition of GPS targeting the warhead accuracy is greatly enhanced. There are still many in the analytical community that question, perhaps correctly, this suggested accuracy of 190 meters to over one kilometer. There can be no doubt that this spin-up technology does improve the accuracy of these warheads over the previously demonstrated poor capability. Since the warheads are not tumbling it in fact enhances the interceptor sensor signature identification capability verses that of a tumbling warheads signature.
Equally revealing is the fact that this is the area where the Iranian Shahab-3 has repeatedly failed in flight test. If the steering vains are not equally positioned correctly or are defective in any way the missile and warhead combination would tumble about its center of gravity out of control destroying the missile. The resulting tumbling warhead whether attached to the remaining missile body or not would in all probability be destroyed during its re-entry. It is known that Iran has and continues to suffer from a steering vain quality control problem for its Shahab-3 ballistic missile that the Germans during WW-II solved and that the United States and former Soviet Union were able to easily resolve with out using specialized coating
Sources and Resources
- David C. Wright and Timur Kadyshev, "An Analysis of the North Korean Nodong Missile," Science and Global Security, November 1993.
- Barbara Starr, "CIA expects Nodong deployment next year," Jane's Defence Weekly, 11 Nov 95, p. 16.
- "North Korea Shops for Nuclear Technology in Russia," by Warren Strobel, The Washington Times July 5, 1994 p.a1 and a8,
- Commission to Assess the Ballistic Missile Threat 15 July 1998
- Delivery Systems, and Chemical, Biological, and Nuclear Programs Anthony H. Cordesman, CSIS Middle East Studies Program, 28 April 1998
- Report: NK Rodong-1 Missile Battalions In Place Jim Lea Pacific Stars and Stripes October 26, 1999 -- North Korea has deployed four Rodong-1 missile battalions — one in North Pyongan Province bordering China and three stationed in North Hwanghae Province near the Demilitarized Zone. Each of the battalions has launch pads for nine Rodong-1 missiles.
 World Fact Book (CIA)]
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