An unarmed intercontinental ballistic missile was launched early Thursday from Vandenberg Air Force Base, officials there reported.
It was the second Minuteman III launched from Vandenberg this week; another missile was tested Sunday.
The missile, which flew from its underground silo at 3:33 a.m., headed for a target in the Kwajalein Atoll in the Marshall Islands — 4,200 miles away.
The Minuteman III is a land-based intercontinental ballistic missile (ICBM), designed to deliver nuclear warheads. Currently it is the only land-based ICBM in service in the United States.
Each missile carries three nuclear warheads, which have a yield in the range of 300 to 500 kilotons. There are 450 Minuteman III missiles in silos located in Montana, North Dakota and Wyoming.
Col. Brent McArthur, 30th Space Wing vice commander, was the launch decision authority.
"It is so exciting to see our mission in action," said McArthur. "We have the potential to launch three times this week, and the last time we did that was back in July of 2004."