The tests appear to have involved "liquid-fuelled, first stage engines" for either North Korea's existing satellitelaunchvehicle, or a new long-range missile first seen during a military parade this year, the institute said.
Although this vehicle currently dominates the commercial satellitelaunch market, it is facing increased competition, especially from the US, where a new rocket developed by the Californian SpaceX company is undercutting Ariane sharply on price.