`Pyongyang advances propulsion tech despite failure`

North Korea has learned more about rocket propulsion technology despite its launch fiasco Friday, experts said, because most countries with such technology have developed it through failure.

Chae Yeon-seok, a researcher at the Korea Aerospace Research Institute in Seoul, said, “A failed rocket launch frequently happens in the initial phase of rocket development. North Korea is also undergoing trial and error.”

The failure is blamed on the process of the rocket’s propulsion power but the North might have learned valuable lessons on the development of a large-scale projectile. The North`s missile Taepodong-1 launched in 1998 weighed 27 tons, but the Unha-2 in 2009 came in at 70 tons and the latest rocket Unha-3 92 tons. Experts said the Unha-3 has apparently used engines whose output is more than 10 percent greater than those of the Unha-2 given that the North must have received large-scale projectile propulsion technology from Iran while sharing missile technologies with it.

North Korea is continuously increasing the range of its long-range rockets. When launching the Unha-2, it separated the first stage of the rocket from the final stage. Through repeated rocket tests, the communist country is advancing its knowledge of related technologies.

Skeptics, however, say the latest failure will serve as a scathing lesson to the North, meaning that Pyongyang must have learned little since the Unha-3 is not different from the Unha-2. Lee Chang-jin, an aerospace engineering professor at Konkuk University in Seoul, said, “A rocket launch needs sufficient tests, and deciding the launch date and hour requires close attention,” adding, “The North seems to have rushed into the launch due to the political event of the country’s founder Kim Il Sung’s centennial birthday (April 15).”