WASHINGTON, Feb. 14 - The nation's fledgling missile defense system suffered its third straight test failure when an interceptor rocket failed to launch Sunday night from its base on an island, leaving the target rocket to splash into the Pacific Ocean, the Pentagon said Monday. The target rocket was launched from Kodiak, Alaska, at 9:22 p.m. Sunday (1:22 a.m. Monday, Eastern Standard Time), but the interceptor that was supposed to go up 15 minutes later remained on its pad in the Marshall Islands, the Missile Defense Agency at the Pentagon said. The target rocket fell into the ocean near Wake...