North Korea Shows ICBM Success, Possibility of Warhead Miniaturization and 7th Nuclear Test

North Korea announced the successful test launch of an intercontinental ballistic missile (ICBM), the Hwasong-17, and announced plans to strengthen its nuclear arsenal. The possibility of launching additional tests or a seventh nuclear test to ensure atmospheric re-entry technology, miniaturization and lightening of warheads for installation of multiple warheads, etc. is raised.

Regarding the test launch of the Hwasong-17 ICBM on the 18th, North Korea’s Rodong Sinmun said on the 20th that it was “the most powerful intercontinental ballistic missile state on the planet,” and that it would “qualitatively strengthen its nuclear arsenal .” On the 19th, the Rodong Sinmun and Chosun Central News Agency reported on an ICBM test launch at Sunan Airport in Pyongyang and an on-site leadership by Chairman Kim Jong-un. The purpose of the test launch was to “examine ‘reliability of the weapon system’ and ‘reliability in operation’.” North Korea announced that the Hwasong-17 had an altitude of 6040.9 km, a flight distance of 999.2 km, and a flight time of 4135 seconds (69 minutes). This is almost identical to the content published by the military authorities. If shot at the normal angle (30-45 degrees), it has a range of over 15,000 km, and the entire US mainland is included in the range.

With this test launch, it is evaluated that significant technological progress has been made in demonstrating successful phase separation and normal flight in a short period of time. In November 2017, the ICBM type Hwasong-15 (range 13,000 km) was launched to unveil the Hwasong-17 type, which has been upgraded to a range of 15,000 km, five years after the completion of the national nuclear force was declared.

However, to have the meaning of an ICBM, the warhead must be able to re-enter the atmosphere and hit the target accurately. To this end, heat shielding technology and precision guidance devices are required to protect the warhead from being burned by the frictional heat of over 6,000 degrees that occurs during re-entry into the atmosphere. Nuclear warheads must be small enough to be mounted on ICBMs.

North Korea’s next step is expected to be to validate its atmospheric re-entry technology. Warheads launched at high angles fall almost vertically on re-entry, so a normal angle launch test is required, which has to endure a great deal of heat when entering the atmosphere at an angle. Places that can launch ICBMs at normal angles include the Pacific Ocean. In order to complete an atmospheric re-entry check, the warhead needs to be retrieved from the impact site, which is also not easy.

After atmospheric re-entry, miniaturization of warheads remains a challenge. Since mounting multiple nuclear warheads on a single missile requires small nuclear warheads, it can conduct a seventh nuclear test for this purpose.

If ICBMs such as the Hwasong-17 are deployed, there is a high possibility that the ‘Intercontinental Ballistic Missile Unit’ will operate them. North Korea first mentioned “intercontinental ballistic missile units” in a report on the 19th. These units are known to be organized under North Korea’s ‘Strategic Force’ and deployed in the border areas between North Korea and China, but their actual role may vary depending on whether ICBMs are use or not.

South Korea and the United States responded with joint air exercises. On the 19th, a US B-1B strategic bomber was dispatched to the Korean Peninsula, and an Air Force F-35A and a US Air Force F-16 escorted the B-1B into the Korean Air Defense Identification Zone, conducting training combined flight .

Chairman Kim warned at the launch site, “If the enemy continues to threaten, our Party and the government of the Republic will resolutely respond with nuclear weapons and head-to-head confrontation.”