South Korea and the US on Wednesday confirmed North Korea’s claim that it had launched a ballistic missile with an intercontinental range, but doubts persisted over whether the communist state had overcome technological challenges to reach the US mainland.

In its report to lawmakers, Seoul’s Defense Ministry said that the Hwasong 14, which the North fired Tuesday morning, was most likely to be a new ICBM-range two-stage missile, a variant of the intermediate-range single-stage Hwasong-12 that the North launched in May. According to Reuters, the Pentagon also concluded Pyongyang test-fired an ICBM, reversing its initial assessment that the missile was a “land-based IRBM.”

The North claimed the missile flew about 2,800 kilometers with an apogee of 933 kilometers -- similar to the assessment of South Korea’s Joint Chiefs of Staff -- meaning that that it could have flown at least 7,000 kilometers if fired at a range-maximizing angle. Any missile with a range in excess of 5,500 kilometers is classified as an ICBM by South Korea and the US.

“Given the missile altitude, flight distance, speed, flight time, we believe (Hwasong 14) is a new ballistic missile with an ICBM range. … Our preliminary assessment is that the missile is a two-stage variant of KN-17,” the ministry said, citing another name of Hwasong 12.

But the ministry was pessimistic about whether the North had secured key ICBM technologies, particularly a re-entry vehicle capable of withstanding extreme temperature and pressure when returning an ICBM back to Earth.

Re-entry technology is considered to be the final component of an ICBM, which also requires a high-thrust engine, stage separation and guidance systems. Without a reliable re-entry vehicle, the missile could spring back to outer space or blow off in midair.

“The success of re-entry technology is hard to see,” Defense Minister Han Min-koo told the National Assembly’s defense committee. “If North Korea wants to prove the missile is an ICBM, they have to show a warhead that can withstand at least 7,000 degrees Celsius.”

Han’s remarks came after the North said that Tuesday’s missile launch verified the carbon-made warhead’s heat-resisting features during its atmospheric re-entry phase, where an ICBM faces a temperature as high as 8,000 degrees Celsius, traveling at about 7 kilometers per second.

Pyongyang’s state-run Korean Central News Agency said the missile’s warhead had endured the “harsh condition” of extreme temperate, overload and vibration and “stably maintained” its inner temperature between 25 and 45 degrees Celsius.

“The test-launch was aimed to confirm the tactical and technological specifications and technological features of the newly developed intercontinental ballistic rocket capable of a carrying large-sized heavy nuclear warhead,” KCNA said.

Aerospace experts suspected that the North has yet to secure reliable re-entry technology, even though it appears clear that Pyongyang has inched closer to developing a nuclear-tipped ICBM capable of reaching the US mainland.

Jang Young-geun, a professor of aerospace and mechanic engineering at Korea Aerospace University, said that unless North Korea presents “hard evidence,” it is difficult to verify the North’s claims about re-entry vehicle.

“From the perspective of an engineer, it is quite difficult to verify their claim unless they retrieve the missile that splashed down the sea, which I think is quite unlikely. Plus, North Korea didn’t even mention about the re-entry vehicle when they made the ICBM announcement yesterday,” said Jang.

Jang also noted that an ICBM would be met with a “completely different re-entry environment” between when being deliberately fired at a lofty angle, as the North did Tuesday, and being launched at a normal angle during the actual combat.

Robert Manning, an Atlantic Council expert, also expressed skepticism, saying Pyongyang is still three to four years away from developing a re-entry vehicle tipped with a nuclear warhead.

It was not the first time that North Korea claimed their advance in re-entry technology. When the North fired the Hwasong 12, they touted the missile had come through “the worst re-entry situation” and struck its intended target.

With South Korea’s military reserving its judgement, some intelligence officials suggested it could have been a success, claiming that the vehicle had successfully communicated with a data center on the ground after surviving extreme heat and vibration.

By Yeo Jun-suk (jasonyeo@heraldcorp.com)







By Yeo Jun-suk (jasonyeo@heraldcorp.com)