North Korea Upgrades Its Long-Range Nuclear Missile

North Korea Upgrades Its Long-Range Nuclear Missile:
"North Korean scientists and engineers have made several major recent improvements to the KN-08  intercontinental ballistic missile that point to a simpler design with greater reliability, analysts at the website 38 North report.
The authors say that physical changes made between 2012 and 2015 will give the North Koreans a better missile, but one that won't be ready before 2020.