North Korea has been a problem for multiple US presidents in recent history, but the country’s ability to launch an ICBM has dramatically accelerated in recent years. It hasn’t been clear how the country achieved this technological breakthrough, but evidence suggests it may have been fueled by Russian rocket engines.
Michael Ellman, of the International Institute for Strategic Studies, argues that the only plausible source for the engines is a Russian or Ukrainian company. Prior to the deployment of its Hwasong-12 and Hwasong-14 missiles, North Korea’s missiles were based on designs that used a modified R-27 Zyb Soviet engine. The Hwasong-10, for example, had a range between 2,500 and 4,000 km (1,500 to 2,400 miles). The Hwasong-12, in contrast, can hit targets 3,700km to 6,000km away (2,300 to 3,600 miles). The Hwasong-14 has an estimated range of 6,700 to 10,400 km (4,200 to 6,500 miles).
Keep in mind that the Hwasong-10 was North Korea’s premiere launch system as recently as 2010. It’s more-or-less unheard of for a country to progress so quickly, particularly when operating under the conditions found in North Korea. Clearly, something dramatically accelerated the advance of the North Koreans. The best candidate? The Soviet-designed RD-250 engine.
One reason Ellman is confident in his estimate is because rockets have their own distinctive designs and layouts that can be visually checked while it’s sitting on the launch pad. There aren’t many countries with ICBM capabilities, and the engines on the Hwasong-12 and Hwasong-14 don’t resemble any rockets made by the US, China, France, India, Iran, or Japan. No rockets from these countries fit the observed characteristics of the NK missiles, either. The one engine that does fit all of the dots on the chart is the Russian RD-250.
There are two potential companies that could have provided the engine: The Ukranian company KB Yuzhnoye and the Russian company Energomash. While the North Korean rocket isn’t identical to the Russian variant (the NKs have a single combustion chamber while the RD-250 originally had two), this type of modification is fairly straightforward and far simpler than building a liquid-propellant engine (LPE) from scratch. Russia used the RD-250 for decades, but decided to transition away from hypergolic fuels, which ignite in the presence of oxygen, because they’re extremely toxic and difficult to work with.
Ellman points out that Russia’s decision to move away from the hypergolic fuels used in rocket engines like the RD-250 left its previous suppliers in an extremely precarious financial position and with dozens, if not hundreds, of rocket engines to spare. North Korea also has historical ties to the Russian criminal underground, and two North Korean agents were arrested and tried for attempting to buy missile technology from KB Yuzhnoye in 2012.
In his report, Ellman goes into more detail on how North Korea likely acquired the missiles and how much work remains to be done before the Hwasong-14 is a viable ICBM platform. If the Hwasong missiles are indeed using Russian or Ukrainian-built engines, it would likely provoke a substantial diplomatic incident.