The launch of a Pukguksong-2 solid-fuel missile from a mobile launcher on May 21 may signal a new level of worries for the US, Japan, and South Korea. (credit: KCNA (North Korean state media))

On Sunday, the North Korean military conducted a second, successful test of the Pukguksong-2, a solid-fuel intermediate range ballistic missile based on a design derived from the country’s submarine-launched ballistic missile. While this might seem like just more saber-rattling from Pyongyang’s leadership given the relatively continuous chain of test launches since President Donald Trump’s inauguration (a total of 10 so far this year), this launch and the launch on May 13 carry a bit more weight.

According to North Korea’s government media, Sunday’s test shows that the Pukguksong-2 is now ready to be “mass-produced.” If true, that development would substantially increase the threat posed by North Korea’s missile force—the Pukguksong-2 can be deployed on tracked mobile launchers, and it uses a “cold-launch” system that requires much less preparation time, which provides much less of an opportunity for the US and allies to detect an impending attack. The tracked launchers also increase the potential number of locations from which the missile could be launched. And the range of the missile appears to be greater than originally estimated.

Sunday’s missile test was tracked by US Pacific Command. The test missile flew in a high-lofting path from North Korea’s west coast across the country and toward Japan, landing in the Sea of Japan. The missile flew approximately 500 kilometers (310 miles) and reached an altitude of about 560 kilometers (about 350 miles). It has an estimated range of 3,000 kilometers (1,900 miles) or more. If launched from within North Korea, the missile could potentially strike all of Japan, South Korea, and even US forces in Guam. By comparison, the Pukguksong-1 submarine-launched missile is believed to have a 1,000 kilometer (620 mile) range.