North Korean reconnaissance satellite exploded in flight uses 'new engine' for space launch vehicle

People watch related news at a waiting room in Seoul Station on Nov. 28 after North Korea reportedly launched a military reconnaissance satellite on the night of Nov. 27 but failed. By Han Soobin

North Korea says it has installed a new engine on a military reconnaissance satellite rocket that exploded in flight less than two minutes after launching on May 27. It is believed that North Korea wanted to demonstrate its technological advancement by using an engine that is mainly used for space launch vehicles, instead of the one used in the successful satellite launch last November. It is also possible that the engine was directly introduced from Russia.

“The launch vehicle, which was fired from the Sohae Satellite Launching Station in Tongchang-ri, Cholsan County, North Pyongan Province, at around 10:44 p.m. on the previous day, was detected as a large number of debris in the sea off the north at around 10:46 p.m.,” said an official from the Joint Chiefs of Staff on the 28th, adding, “It exploded shortly after launch. At this stage, we can only speculate that there may have been a problem with the combustion system.”

Acknowledging the failure of the launch the previous day, the Korean Central News Agency said, "We have reached a preliminary conclusion that the cause of the accident lies in the operational reliability of the newly developed liquid oxygen and oil engine.” The military reconnaissance satellite 2, which was blown up in the air, was referred to as ”Manlikyung-1-1,” and the rocket carrying it was referred to as “New Satellite Carrier Rocket.” The rocket's propellant consists of fuel and an oxidizing agent. Instead of oxygen, it gains a flying force from energy generated when the oxidizer burns fuel.

North Korea used “unsymmetrical dimethylhydrazine (UDMH) + red fuming nitric acid” as a propellant for its "Chulima-1" model last year. It is also known as the "Baekdu Mountain Engine." Hydrazine is a toxic substance with relatively low propulsion, but it is easy to store and fire. For this reason, it is primarily used for military purposes. The engine is also used for intercontinental ballistic missiles (ICBMs), such as Hwasong-15 and Hwasong-17.

What North Korea refers to as the propellant for its new rocket, "oil engine (kerosene) + liquid oxygen" is mostly used for space launch vehicles. Kerosene is called petroleum in North Korea. Liquid oxygen, an oxidizing agent, should be stored at ultra-low temperatures of minus 183 degrees Celsius. It is difficult to maintain the gas for a long time after being injected into a rocket, but the propulsion is relatively strong. It is used in South Korea's Naro and Nuri rockets, and SpaceX's Falcon.

If North Korea used kerosine instead of hydrazine as fuel, it would be the first time for the North to do so. It is interpreted that Pyongyang sought technological advancement in line with global trends. It also seems to get a justification to claim that the projectile is not for military use but for scientific use. However, the Joint Chiefs of Staff believes that it needs to further analyze what fuel the North actually used. "Since it exploded in the early stages, we need to analyze the data to find out (the type of fuel)," an official from the Joint Chiefs of Staff said.

Some analysts say that North Korea may have directly introduced the “kerosene + liquid oxygen” propellant from Russia. Even if Russian engineers provided assistance to North Korea after the North Korea-Russia summit in September last year, it would be difficult to develop a new propellant six months after its launch in November last year. Liquid oxygen, an oxidizing agent, is difficult to handle and takes at least two years to develop. Several engine combustion tests before the latest launch add weight to the analysis.

Jang Young-geun, head of the Missile Center at the Institute for National Security Strategy, said, “Rather than developing an engine for cryogenic propellant in a short period of time, it is more likely that North Korea introduced the engine from Russia in exchange for cooperation and conducted several ground combustion tests before launching it.”

The failure of the launch puts North Korea's goal of launching three more reconnaissance satellites this year out of reach. Hong Min, a senior researcher at the Korea Institute for National Unification, said, "It is inevitable that the third satellite launch plan will be disrupted this year," adding, "It is expected that up to one or two will be possible this year."

※This article has undergone review by a professional translator after being translated by an AI translation tool.