A new defensive missile system is being activated and controlled from Peterson Air Force Base and Cheyenne Mountain. The system is designed to stop incoming missiles before they hit their target, and will become operational later this fall.

On Thursday, a ceremony was held at Peterson to mark the activation of the unit that will direct command and control for this new line of defense. Their official name is the Ground-Based Mid-Course Defense Brigade or GMD. Their job will be to operate the new missile defense system.

When an intercontinental ballistic missile is fired, it enters low-earth orbit before reentering the atmosphere and striking its target. This new defense system will destroy an incoming missile before it can reach that point.

Lieutenant General Joseph Cosumano says these missiles will protect America from attack by a rouge or terrorist group with access to long-range missiles. "This is the first opportunity in 30 years to develop and build and field a capability to defend the United States of America."

The missiles will be based in Alaska and California, but will be controlled from Peterson AFB and Cheyenne Mountain. "It's a natural fit for us, because the center of space for the entire world is right here in Colorado Springs."

Most of the 90 soldiers in the GMD will be from the Colorado Army National Guard. "The National Guard has been in homeland defense since 1936, so this is not a new mission for us," said Adjutant General Mason Whitney.

Officials say they will work to improve the system's accuracy by continuing to test it even after it becomes operational.