North Korea’s Second ICBM Test: Preliminary Analysis

A very quick and preliminary first thoughts post on North Korea’s second ICBM test, which came upon the date that North Korea celebrates “victory” in the Korean War. These thoughts are very much subject to further information, currently limited, and release of imagery and videos of the test by North Korea. Political implications etc left aside for now, as are links and so on. All of that will come.

The second ICBM test had a range of about 1,000km and an apogee of 3,7000km. Both figures are higher than for the first ICBM test, that is for the initial Hwasong-14 test (about 938km range and 2,8000km apogee).

The most important thing about the second test is the range and the second stage. These numbers are marginal improvements upon the original, so the second test isn’t any more significant from an RV perspective than the first. The RV landed in Japan’s Exclusive Economic Zone, which naturally leads to questions about guidance.

If fired on a standard trajectory the missile launched today would have a range of 10,400km (6,700km for the first) and taking the Earth’s rotation in account if fired in an easterly trajectory (direction of US mainland from North Korea) it would have a greater range (8000km for the Hwasong-14).

Taking into account the 1,300km difference for the Hwasong-14 and using that as a rough guide we get a maximum theoretical range of 11,700km if launched on a MET trajectory in an easterly direction. That’s theoretical. Taking into account the direction of cities beyond the West Coast lowers the maximum range. According to David Wright at the Union of Concerned Scientists that puts Los Angeles, Denver, Chicago most certainly within range and Boston, New York likely (just) in range.

I should stress that these range estimates are subject to the payload of the missile, which could be heavier than the dummy RV’s employed in testing which would lower actual combat range.

Speculation exists as to the second stage. Michael Elleman is of the view at 38North that the Hwasong-14 second stage employed an Unha Space launch Vehicle third stage, and that the range increase for the second ICBM test comes via a new second stage. We know that recently, prior to the Hwasong-14 test, North Korea statically tested a new engine suitable for a second stage ICBM. A KCNA statement from North Korea, however, implies that the original Hwasong-14 test held back on the range and this second test was conducted to maximum range.

This implies that today’s test was of the Hwasong-14 ICBM (KN-20) without significant modification. I am not certain about that at this stage, so will leave aside further commentary for as to whether this is a new missile for now.

Update. A KCNA press statement on the test *implies* that the maximum range Hwasong-14 ICBM (today’s test was of the Hwasong-14) employed a cluster of March 18 Revolution engines to extend range. I emphasise “implies.”

Update. I’ve seen imagery of the July 28 test and from external appearances the missile looks like the Hwasong-14 ICBM, which makes the KCNA press statement reference to multiple motors intriguing. Perhaps the second stage consists of a cluster of new second stage engines first statically tested prior to the Hwasong-14 July 4 test.

Update. Here’s a good pic of the July 28 Hwasong-14 test. That’s the Hwasong-14 first stage. So taking North Korea at its word implies that the new multiple motor arrangement refers to the second stage.

Update. Here’s the relevant line from the KCNA Press Statement; “confirmed the performing features of motors whose number has increased to guarantee the maximum range in the active-flight stage as well as the accuracy and reliability of the improved guidance and stability system.” That could be a reference to the performance parameters of the engine rather than an increase in “motors.” That could have been achieved through higher, maximum design, pressure in the combustion chamber of the booster engine, which would provide greater thrust.

There’s a cell phone video of the second ICBM test from Japan’s northern most main island, Hokkaido, showing what looks to be the dummy RV reentry. That North Korea was getting ready for another test was picked up by US intelligence well in advance. This test, more strongly than the first, met Ashton Carter’s, former US Secretary of Defense, criteria for a BMD intercept test.

There was no attempt.

The Missile Defense Agency doesn’t do combat readiness tests, after all.