The Navy's Zumwalt-class destroyer program is slated to complete operational testing in December -- a 15-month delay from its September 2021 goal. Earlier this year, the Navy told Inside Defense that the service was “ reevaluating ” the timeline for the newest destroyer class, DDG-1000. An annual review released today of the Defense Department's most expensive weapon systems by the Government Accountability Office found that the Navy intends to mature the destroyer’s three remaining technologies -- infrared signature, volume...