Many are worried about the threat of a North Korean missile striking somewhere in the United States-- and large parts of the defense system to stop that from happening are based in Alaska.

At Clear Air Force Station in Nenana, an 11-story radar can see 240 degrees and 3,000 miles into space, according to 2-13th Space Warning Squadron commander Lt. Col. John Oberst. There's another radar called Cobra Dane on the island of Shemya. Five others in Greenland, the UK, Massachusetts, California and North Dakota provide radar coverage of the whole of North America, up into the Arctic and over into western Europe.

Oberst said they know immediately if a missile is launched anywhere on earth and can track it with one of the seven radar. Eighty percent of the staff at Clear are Alaska National Guardsmen. The rest are active duty Air Force and Royal Canadian Air Force members.

Oberst said they're always watching and always ready.

"We do detect about a half dozen missiles a year and our operators execute those as if they were in a simulation. So it's not high stress for the operators because they're very well trained,” he said.

Once a missile is detected, the radar track it and its flight path is pushed up the chain of command. If the missile is determined to be a threat, the interceptors at Fort Greeley near Delta Junction are launched.

The interceptors would cause the missile to detonate in space. The commander of the 49th Missile Defense Battalion, Lt. Col. Olando Ortega, said they had a successful test one month ago and he's confident in the system and the Alaska National Guardsmen who operate it.

"We do drills every day, 24 hours a day, 365 days for that one moment and so we have confidence in the ability of our soldiers because of their training and confidence in the system itself because it has been tested,” said Ortega.

The system at Clear is getting an upgrade so it can communicate directly with the system at Greeley. The upgrade is expected to be complete by mid-2018.

The THAAD (Terminal High Altitude Area Defense) system also recently had two successful intercept launches on Kodiak. THAAD is not a permanent installation in Alaska but is another tool in our nation's missile defense program