An unarmed Minuteman III missile was destroyed over the ocean early Friday, minutes after launch because controllers couldn't track it properly to be sure it was going in the right direction.

The loss of tracking information "necessitated terminating the mission in the interest of ensuring down-range safety," an Air Force statement said.The ballistic missile's flight was terminated five minutes after the launch as it was heading toward the Kwajalein Missile Range in the Marshall Islands, 4,200 miles away.