By Michael Elleman, Senior Fellow for Missile Defence
Photographs and video released by North Korea reveal that the Hwasong-15 test fired on November 29 is not a modified version of the Hwasong-14, as initially assessed here based solely on flight data. The Hwasong-15 is considerably larger than the Hwasong-14, and initial calculations indicate the new missile could deliver a moderately-sized nuclear weapon to any city on the US mainland. The Hwasong-15 is also large and powerful enough to carry simple decoys or other countermeasures designed to challenge America’s existing national missile defense (NMD) system. A handful of additional flight tests are needed to validate the Hwasong-15’s performance and reliability, and likely establish the efficacy of a protection system needed to ensure the warhead survives the rigors of atmospheric re-entry.
The Hwasong-15 is a two-stage, liquid-fueled ICBM. Photographs of the Hwasong-15 reveal that its first stage is powered by a pair of engines that share the same external features found on the single chamber engine used by the Hwasong-14. The two-chamber configuration found on the Hwasong-15 is very similar to the original design of the RD-251 engine block developed and produced in the former Soviet Union, suggesting that the total thrust generated at lift-off is about 80-tons force. This is reasonably consistent with the estimated mass of the new missile, which is between 40 and 50 metric tons. The configuration of the second stage is not known, though its overall size suggests it contains 50 percent more propellant than the Hwasong-14. Taken together, and applying conservative assumptions about the second-stage propulsion system, it now appears that the Hwasong-15 can deliver a 1,000-kg payload to any point on the US mainland. North Korea has almost certainly developed a nuclear warhead that weighs less than 700 kg, if not one considerably lighter.
Read the full article at 38 North