"North Korea has experienced a string of rocket failures over the past year. Of at least nine launches, six were failures. Several of the test failures involved the more advanced, longer-range Musudan missile. These missiles launched earlier this week were older, more reliable Hwasong-7 types. Descended from the famous Scud missile and otherwise known as Scud ER (Extended Range), Hwasong-7s are short-range range ballistic missiles with an operational range of about 600 miles.
Within hours, the United States military deployed a pair of Terminal High Altitude Area Defense (THAAD) missile systems to South Korea. The missiles were delivered by C-17 transport to Osan Air Base 40 miles south of the capital Seoul. Developed by the U.S. Army, THAAD is designed to intercept incoming ballistic missile warheads at high altitude. THAAD can defend a larger geographic area from missile attack that the shorter-range Patriot PAC-3 system." PM
http://www.popularmechanics.com/mili...sile-us-radar/