WASHINGTON – The failure of North Korea’s three-stage Unha-3 rocket on Thursday (March 12) was most likely caused by severe vibrations at an early point in the flight trajectory known as Max Q, or maximum dynamic pressure, about one minute into the launch, according to a rocket expert.
While the lower stages of the North Korean rocket continued to function for several minutes, resonance at the top of the launch vehicle resulted in “catastrophic disassembly of the third stage at Max Q,” said Charles Vick, senior technical and space policy analyst at GlobalSecurity.org. “The vibrations just tore it apart.”
The third stage along with a satellite payload shroud failed about one minute into flight, analysts said. North Korea claimed the flight test, which drew international condemnation, was designed to place a satellite into a polar orbit. But many experts, including Vick, believe Pyongyang was testing the three-stage rocket for use as a ballistic missile.
North Korea's Unha-3 rocket lifts off on Thursday. The planned orbital flight lasted only about four minutes