The test measured the thrust power in the combustion chamber, the structural safety and reliability of the engine, and the movement of the turbine pump, the Korean Central News Agency said. It reportedly took place at the Sohae Satellite Launching Ground, in North Pyongan Province.

CNN military analyst Lt. Gen. Mark Hertling said advances in North Korea’s rocket system could help with the country’s development of ICBMs — intercontinental ballistic missiles.

“Some of these technologies which the North Koreans are including in their rocket expansion program actually have to do with a covert method of firing missiles without being detected in advance of actually exploding the devices. So that’s part of the issue,” Hertling said.