At its latest test observed by leader Kim Jong-un, North Korea may have tested a new rocket engine fit for a satellite launch vehicle rather than an intercontinental ballistic missile, a US expert said.
The weekend test at the Sohae satellite launching ground was successful, according to Pyongyang's official KCNA news agency. Kim was quoted as saying the world would soon see "what eventful significance the great victory won today carries".
"Now they have shown us an engine that would be a good fit for this vehicle, and they have told us what they plan to do with it," John Schilling said in an article carried by 38 North, the website of a US research institute.
"The North Korean regime has never been shy when it comes to bragging about their missiles. This time, it seems they are bragging about a space program," he said.
North Korea's rocket launches are seen as crucial steps toward Pyongyang's ultimate goal of a nuclear-armed missile capable of reaching the US mainland. In February last year, Pyongyang put a satellite into orbit under its Kwangmyongsong program which began in 1998.
At that time, the South's defense ministry said that North Korea is capable of launching a missile with a range of 12,000 kilometers, though it has yet to master technology needed to bring a launched missile back into the atmosphere. An intercontinental missile capable of delivering a payload needs to be able to reenter the atmosphere without breaking up.
After analyzing photographs released by Pyongyang's state media, Schilling said North KOrea tested a propulsion system consisting of one core engine surrounded by four verniers was tested.
It's similar in size and appearance to an engine, tested last September, which is better suited for use in satellite launch vehicles than ballistic missiles, he said, adding the core of the new engine may be slightly smaller than what was tested before.
"Whatever the underlying heritage of this engine, it appears that the combination of the core engine and verniers is too large to fit in any of North Korea’s known ICBM prototypes, or in any missile that could be carried on any of its mobile launchers," the US expert said.
"Unfortunately, we cannot be 100 percent certain of that assessment from the photographs available so far."
With four steering engines around a single core, the engine is probably meant to be used alone rather than clustered and the best fit for this engine would be as the second stage of the Unha-9 satellite launch vehicle, the expert said.
"However, we cannot rule out other possibilities, such as a yet-unknown ICBM design sized for this engine. But North Korea has been moving towards lighter mobile systems and solid propellants for their strategic missiles," he said.
In February, North Korea claimed to have successfully launched a new strategic intermediate-range ballistic missile with an improved solid fuel engine capable of carrying a nuclear warhead more accurately from any place. At that time Pyongyang said it has acquired improved technologies related to a nuclear warhead, re-entry and guided flight.
Kim has vowed to launch more rockets capable of carrying nuclear warheads, claiming Pyongyang has acquired re-entry technology, despite doubts about its ability to miniaturize a nuclear warhead to be mounted on an intercontinental ballistic missile.
This year, North Korea has threatened to launch an ICBM at a time and place determined by Kim who said in his New Year's address that Pyongyang had reached the final stage of ICBM development. US President Donald Trump vowed to stop Pyongyang from mastering ICBM capabilities.
Lim Chang-won = email@example.com