On February 12th North Korea conducted a test a new mobile ballistic missile test in which the “Polaris 2” was successfully fired from canister on a tracked vehicle acting as a TEL (Transporter Erector Launcher). The TEL used the same cold launch used by the North Korean “Polaris 1” SLBM (submarine launched ballistic missile). The Polaris (or Pukguksong) 2 appeared to be the same missile as the Polaris 1, except that it was fired from a canister on a TEL instead of a silo in a submarine. A mobile TEL carrying a ballistic missile that can reach all of South Korea and parts of Japan (and China), especially one armed with a chemical or nuclear warhead, makes North Korea a much more dangerous threat, North Korea achieved this by illegally obtaining components for the TEL, the missile and quite possibly the cold launch capability. Most of this tech can be traced back to known North Korean relationships, usually illegal ones) with suppliers in Russia, China and Iran. Some items were illegally obtained from Japan and European nations. That North Korea has all this tech is now a fact. Exactly how they got it is another matter and details on that will take another decade or so to emerge.
Many of these illegal tech sources have become visible since 2000. For example in 2013 the UN concluded that North Korea had illegally converted Chinese lumber transports into TELs for the recently revealed North Korean KN-08 ballistic missiles. Markings on the TEL seen at a parade identified it as “Hwasong-13 Self-Propelled Launcher.” The North Korean TEL was a large truck specially built to carry, then erect and survive the launch of, a ballistic missile. The North Korean TEL was unlike any seen before up there but the cab was similar to a Chinese heavy transporter. It was initially believed that North Korea bought these heavy trucks and then modified them into TELs. This is what Iran did for a long time, until sanctions officials ordered heavy truck manufacturers to stop selling Iran the big vehicles that could be converted to TELs by the buyer. It eventually discovered that the North Korean TEL was based on a Chinese vehicle exported to North Korea as a lumber transporter (a legitimate use for trucks like this).
Large trucks modified to be TELs are often not real TELs. There are a lot of manufacturers out there who build huge (12-20 wheel) trucks, and these are often used to carry military equipment (like 60 ton tanks). A 12-50 ton ballistic missile is no problem but installing the hydraulic gear and controls to erect the missile to a vertical position is tricky. Even more difficult is hardening the rear of the vehicle to minimize the damage from the rocket exhaust. That damage can be avoided by using the cold launch technique. This involves using a gas generator to boost the missile to a certain height where the missiles propellant ignites and takes over. Cold launch not only saves wear-and-tear on the launcher but also decreases the exposure of the launching site to surveillance and thus increases missile and launch site survivability. Using a tracked vehicle for a TEL is essential for North Korea, which only has about a thousand kilometers of paved roads. There are a lot of unpaved roads and even more that can be described as dirt tracks that are impassable by heavy trucks when muddy. Thus the Polaris 2 and its TEL are a dangerous new threat to the neighbors.
The Polaris missile was no surprise. There have been eleven test launches of the original SLBM version since October 2014. Also known as the KN-11 all tests took place off the east coast. The first two tests (one of them a failure) were from land based silos to test the silo container and especially the cold launch mechanism. Test 4 was in January 2015 was also from the land base and was a success. There was another such test three months later, also a success. Test 6 was in May 2015 was similar to the last previous two, was also a success. Test 7 in November 2015 was from a submarine and was a cold launch failure. Test 8 in December 2015 was publicized and showed a SLBM breaking the surface (from a barge, not a sub as North Korea claimed), the engine igniting and then the missile exploded. This one was a partial success. Test 9 in April 2016 was another partial success with the SLBM breaking the surface via a successful cold launch, igniting its solid fuel rocket motor and not exploding. However the SLBM only went 30 kilometers because of a non-explosive propulsion failure. Test 10 was in July 2016 and showed a SLBM breaking the surface (from a sub), the engine igniting and then the missile exploded when it was about 10,000 meters (32,000 feet) high. This one was a partial success. Test 11 was in August 2016 was apparently a success. The proof was a video that showed the missile breaking the surface, the rocket engine igniting followed by rapid movement up and away. Japanese sensors detected the missiles landing about 500 kilometers from the launch site.
Many of the early tests were from a submersible barge that was developed by Russia and first used in the 1960s. The last three Polaris 1 tests were from what appears to be a North Korea built Whale (Gorae) class sub. These last three tests were not all successful but the latest (test 11) proved that the North Korean design was capable of doing everything an SLBM is supposed to. All these SLBM tests also indicate that while the North Korean SLBM was clearly based on the 1960s Russian R27 SLBM it included some major new tech. For example the North Koreans appear to have replaced the original storable liquid fuel engine with a solid fuel rocket motor. While the latter requires less maintenance onboard and is more reliable, it has half the range (about a thousand kilometers) compared to the R27 (over 2,000 kilometers).
North Korea obtained all or parts of a Russian R-27 SLBM in the 1990s. The R-27 is 1960s vintage tech that was replaced in the 1970s by more modern designs. But many of the unused R-27s were recycled for scientific research until 1990. Some 500 R-27s had been launched with an 87 percent success rate. It was believed that all or much of at least one missile was illegally sold as “scrap” to North Korea in the 1990s. This was deduced from the fact that after the Soviet Union collapsed in 1991 North Korea bought a lot of discarded Russian weapons for scrap. None of this stuff was supposed to be operational or contain tech that could easily be made operational. It was later discovered that some of the demilitarized scrap was remilitarized by the North Koreans. Thus it was no surprise that the new North Korean ballistic missiles looked a lot like the R-27.
North Korea also received ten decommissioned Russian Golf class SSBs (diesel-electrinc subs with one or more missile silos) in 1993, to be turned into scrap. The Golf class boats used the 16 ton R-21 SLBM, which is thinner and longer than the R-27 that replaced it for the first Russian nuclear powered SSBNs (large nuclear powered subs with a dozen or more missile silos) in the 1960s and 1970s. Foreign intelligence agencies have been watching North Korea carefully for signs that North Korea was working on an SSB but the only possibility found was one new submarine under construction. It did not look like a copy of the Golf class boats but did have a sail that might have held an R-27/Musudan type SLBM. In any event this boat seemed to be under construction a long time and largely hidden from view. The scrapped Golf boats enabled the North Koreans to examine the first generation SLBM launch equipment, in which SSBs fired missiles from an elongated sail structure that contained three SLBMs. The eventual appearance of the Gorae SSB and the Polaris 1 SLBM is another example of North Korea adapting decades old weapons so they could be built in North Korea. The only missing piece is a nuclear warhead small and rugged enough to fit into the Polaris 1 and actually detonate. North Korea says this is being worked on.