Global Security.org
The US "successfully intercepted" an intercontinental ballistic missile target waryead 30 May 2017. The Ground-Based Interceptor was launched from Vandenberg Air Force Base in California shortly after 3:30 PM ET. A little more than one hour later, the Pentagon confirmed that it had successfully collided with the target over the Pacific Ocean.
The US Defense Department conducted the missile defense system test as North Korea continued the development of intercontinental ballistic missiles capable of reaching the US mainland. The test occurred just days after the North Korean regime launched its ninth missile this year. The test involved launching a target meant to simulate an ICBM from a base in the Marshall Islands and then shooting it down with a ground-based interceptor launched from Vandenberg AFB in California.
The US government plans to strengthen its missile defense to protect the mainland by deploying additional 8 interceptors in Alaska, bringing the total to 44 nationwide by the end of 2017
https://www.globalsecurity.org/space/systems/gbi.htm