On October 2, 2019, South Korea's Joint Staff Headquarters said north Korea fired a submarine-launched ballistic missile suspected to be the Polaris series eastward off the coast of Wonsan in Gangwon Province at about 7:11 a.m. that day. The missile has a maximum flight altitude of more than 910 kilometers and a flight distance of about 450 kilometers, and the missile may have carried out "inter-stage separation" during flight. The next day, KCNA announced that it had successfully test-fired the Polaris 3 submarine-launched ballistic missile on the 2nd. This is the first test launch of the missile since it was first made public in 2017, marking a new phase in north Korean submarine-launched missile development
A brief analysis of the performance of the Polaris 3 submarine-launched missile
After roughly calculating the diameter of the Polaris 3 submarine-launched missile, combined with the water picture of the missile projectile released by the DPRK, it can be found that the length-to-diameter ratio of the missile is about 6, according to which the length of the missile is about 10 meters. Coincidentally, the U.S. website at 38 degrees north latitude displayed an Aug. 26 satellite photo of North Korea's Shinpo submarine base before the launch of the Polaris 3 missile, in which four ships were moored: a diving barge for underwater launch tests, a support vessel, a 17.5-meter-long small submarine (which may be used to observe the readiness of underwater platform launches and transport frogmen to solve underwater technical problems) and the "Shinpo" class ballistic missile submarines. People and objects were observed on the docks close to submarines and barges, cranes and cylindrical cylinders 10.35 meters long and 1.75 meters in diameter were observed on trucks, with two auxiliary vehicles on either side of the truck.
At that time, the US satellite discovery may be a container for the "Polaris" 3 submarine-launched missile, which can fit into the cylinder found by the US satellite. That is to say, the length of the Polaris 3 missile is about 10 meters, which is equivalent to the length of the Polaris 2, but the diameter is thicker than the Polaris 2 (the length-to-diameter ratio of the Polaris 2 is about 7). Polaris 1 has a length of about 9 meters, a diameter of about 1.5 meters, a weight of about 14 tons, a range of more than 1,000 kilometers and a length-to-diameter ratio of about 6. According to the size of the missile, it can be judged that the weight of the North Korean "Polaris" 3 missile is comparable to the K4 submarine-launched missile under development by India, which is about 18 tons, and the maximum is 20 tons. Polaris 3 has two stages of engine, the first stage is about 5.5 meters long, the second stage is about 3 meters long (including the nozzle and the interstage segment), and the warhead part (including the guidance equipment cabin) is about 1.8 meters long, which can be inferred from the trunking that extends down from the side of the core stage, and these wires transmit the control command from the top level to the thrust control system of the first stage. The interrupt of the trunking marks the interstage segment between the first and second stages. The solid engine of polaris 3 is larger than India's K-4 submarine-launched missile, but about 2 meters shorter in length. The first stage thrust of the Indian K4 submarine-launched missile is about 43.14 tons, the combustion time is 74.8 seconds, and the second stage thrust is 20.8 tons, and the combustion time is 37.7 seconds. The first stage of the K-4 submarine-launched missile has a diameter of 1.4 meters and a length of 5.5 meters; the second stage has a diameter of 1.4 meters and a length of 1.4 meters, with a cumulative weight of about 17.2 tons and a load of 16.7 tons of fuel. North Korea's Polaris 3 has a thrust estimate of the same as K4, but the burning time of the first stage will be shorter, and the burning time of the second stage will be longer, which is caused by the ratio of the two stages of north Korean missiles to about 2:1.
The design of India's K4 submarine-launched missile is also very similar to that of north Korea's Polaris 3. The Polaris 3 missile no longer adopts the conical warhead design with a stabilizing skirt used by polaris 1 (derived from the Soviet R-27 submarine-launched missile, which can effectively reduce the resistance when flying in the atmosphere), but adopts an oval blunt head design similar to the US "Trident" series of submarine-launched missiles, which is more suitable for underwater movement and drag reduction of the missile. However, compared with the cone warhead, this design has greater flight resistance in the atmosphere, which will affect the flight performance and range of the missile in the atmosphere. At present, it is unclear whether the North Korean technicians intend to design a retractable drag reduction rod inside the head fairing with reference to the "Trident" or the "double hood" design in reference to the "Giant Wave" 2. The JL-2 submarine-launched missile adopts a double-hood design with a blunt-headed fairing on the outside of the missile cone fairing to solve the problem of the contradiction between the missile's movement in the water and the atmosphere. When the missile is ignited, the blunt-headed fairing is thrown away, and the missile exposes the cone fairing before flying in the atmosphere. This design can effectively improve the fluid performance of underwater motion without reducing the flight performance of the missile in the atmosphere, but the disadvantage is that it increases the complexity of the launch process, mainly the step of adding a low-altitude throwing cover, which is also not conducive to the reduction of the size and weight of the missile. If there are no improvement measures above, it will affect the increase in the range of Polaris 3. In addition, there is a view that the Polaris 3 submarine-launched missile may use active cavitation technology to reduce the resistance of underwater movement. There are holes in the bottom side of the head fairing, which may be bubble-generating holes used to generate bubbles that envelop the projectile underwater, isolating the projectile from contact with seawater, although it may also be some kind of small throwing engine. If North Korea makes progress in miniaturizing nuclear warheads, it is not excluded that Polaris 3 will carry cluster warheads.
The range of India's K4 submarine-launched missile is said to exceed 3,500 kilometres, and north Korea's Polaris 3 is essentially at the same level. Considering that the Polaris 3 missile flew much higher than the Polaris 2, the flight time lasted 17 minutes, which means that if North Korea launched the missile at a normal angle, its flight distance would be longer. Shin Jong-woo, chief analyst at the Korea Defense and Security Forum (KODEF), said that polaris 3 is completely different from the previous two models, and the maximum range may reach 5 000 kilometers. However, there is no doubt that the missile has a range of 1,900 to 2,000 kilometres, and if a range of 5,000 kilometres is to be achieved, it is more likely that it will be a land-based extended version of the " Polaris " 4 long-range missile . From the design point of view, the design of the Polaris 3 is similar to that of submarine-launched missiles owned by China, Russia and the United States. Compared with the "Polaris" 1, which has greater symbolic significance than actual combat significance and insufficient throwing weight, polaris 3 can already be considered a medium- and long-range submarine-launched ballistic missile with considerable technical strength and combat capability, and can be equipped in batches and ready for combat duty after full testing. The analysis believes that at a time when the DPRK-US denuclearization consultations are in a standstill, north Korea may demonstrate its defensive capabilities by disclosing new weapons, while exerting pressure on the United States. Nam Se-gyu, director of the South Korean Institute of Defense Sciences, said that it will take several years for north Korea's "Polaris" 3 new submarine-launched ballistic missile to complete the actual combat deployment, and from the perspective of angle of fire, altitude, range, etc., "Polaris" 3 is completely different from "Polaris" 1, and the range is 50% more. He believes that the DPRK intends to test the maximum effectiveness of Polaris 3 when launched from underwater. The South Korean military may introduce the standard THREE anti-aircraft missile "SM-3" to deal with the "Polaris" 3. The long-range surface-to-air missile L-SAM, which is being developed by the ROK military, will soon enter the system development stage, and it is expected that the actual deployment will take 10 years, and the ROK military is trying to complete its deployment before north Korea deploys submarine-launched missiles.
On October 4, 2019, Rodong Sinmun, the organ of the Workers' Party of Korea, published an article saying that the Polaris 3 submarine-launched ballistic missile (SLBM) was not a show of force, but a solemn statement issued by the North Korean people to the anti-DPRK forces around the world and against the trend of history. According to the article, Polaris 3 can choose its own launch site, the range of the film is beyond imagination, can enter the atmosphere, and look down on the nest of hostile forces. The analysis pointed out that the DPRK stressed that its national defense strength is sufficient to counter hostile forces, which is intended to show that it will not succumb to the unilateral demands of the US side in the future DPRK-US denuclearization negotiations. The article said that it is necessary to rely on unlimited power and the power of independent innovation in scientific research, as well as the super-high-speed creative ability to invalidate the weapons of the imperialist powers, to launch a cannon of self-sufficiency in all areas of socialist construction. There is a view that North Korea aims to dispel internal fears of weakening its defense forces and inject vitality into economic construction by vigorously publicizing the success of the test. Another analysis believes that the DPRK's projectile is directly related to the DPRK's recent new submarine. North Korea currently has more than 20 Romeo-class (1,800-ton) submarines, more than 40 Shark-class (325-ton) submarines, more than 10 Salmon-class (130-ton) submarines, and is also currently building Shinpo-class submarines capable of carrying submarine-launched missiles. North Korean state media released images of State Affairs Committee Chairman Kim Jong-un visiting the new submarine in July. Some South Korean military experts speculate that North Korea is building a new type of submarine capable of firing multiple submarine-launched missiles at the same time, with a displacement larger than that of the Shinpo class. In the future, if the combination of boats and bombs is realized, then North Korea's underwater nuclear counterattack capability will be greatly enhanced. North Korea may use underwater launch platforms for emergency combat readiness before missile submarines are equipped with troops.
epilogue
The advent of the Polaris 3 submarine-launched missile represents another big step forward for North Korea in its search for a maritime deterrent. North Korea may conduct more flight tests in the future, including eventually underwater launch tests from submarines. North Korea will also need to build at least 3, if not 4 or 5, ballistic missile submarines to ensure that it has a "second strike back" capability, meaning that it will take at least 6 years, if not longer, for North Korea's submarine-launched ballistic missiles to be put into service.
In addition to advances in submarine-launched missiles, North Korea has recently tested "super-large rocket launchers" several times and achieved bursts of fire. South Korea's Joint Staff Headquarters said on November 28, 2019, that South Korean forces detected North Korea firing two short-range weapons from the Lienpo area of South Hamgyong Province into the eastern waters of the peninsula at 4:59 p.m. that day. It has a flight distance of about 380 kilometers, a flight altitude of about 97 kilometers, and a firing interval of about 30 seconds between the two. On the 29th, the KCNA reported that Kim Jong-un, chairman of the DPRK State Affairs Commission, visited the scene and fired a series of super-large rocket launches. This is the fourth time that North Korea has tested a super-large rocket launch in 2019, and this is the first time that it has been declared a "continuous test launch" to the outside world. The military technical superiority and reliability of the weapon system were demonstrated through a series of test firings aimed at finally checking the combat suitability of the super-large rocket launcher. The analysis believes that the DPRK's super-large rocket launcher has entered the final stage of verifying performance. This is also the 13th time in 2019 that North Korea has launched a vehicle, in which the supersized rocket launcher, which is speculated to be a caliber of 600 mm (referring to the caliber of the launch tube), was previously launched on August 24, September 10, and October 31, respectively. Experts believe that the rocket launch on October 31 was launched more than 3 minutes apart, and the continuous firing stage had not yet been reached. Compared with the last time, the flight distance and altitude of the rocket launched by the DPRK this time have been improved, and the time interval has been shortened to more than 30 seconds, and the continuous firing performance has been verified. North Korea aims to intensify tensions on the peninsula through low-intensity provocations as the DEADLINE for denuclearization negotiations between the DPRK and the United States approaches, and put pressure on South Korea and the United States. By solving the problem of continuous fire, it is also conducive to the future development of submarine-launched missile salvo technology by North Korea.