North Korea's rocket launch Sunday has raised concerns among Japanese officials and experts that its grasp of missile technology is advancing at a worrying clip.
The latest rocket, which Seoul said flew about 5,500 km from the Dongchang-ri launchpad in North Korea before crashing into the Pacific Ocean, is believed to be significantly larger than the one test-fired in December 2012 and would require a more powerful propulsion system.
The test appeared to be largely successful, demonstrating Pyongyang's considerable progress in its quest to master missile technology, experts interviewed by The Japan Times said.