USS Zumwalt completes sea trials after hypersonic missile modernisation

USS Zumwalt completes post-modernisation sea trials

The United States Navy (US Navy) destroyer USS Zumwalt (DDG-1000), the lead ship of its class, has successfully completed a series of sea trials. The tests followed more than a year of work and preparation at Huntington Ingalls Industries (HII) facilities in Pascagoula, Mississippi. The activity formed part of a major, far-reaching modernisation programme intended to equip the vessel to employ and launch hypersonic missiles, in line with the force’s requirements for this new category of weapon.

According to information officially released by HII on 21 January, the trials confirmed that the principal systems installed and integrated aboard the ship were operating properly following the modifications. These checks covered the propulsion plant, electrical power generation, navigation and control systems, as well as several critical subsystems affected by the operational conversion process. This milestone confirmed expectations raised days earlier, when Zumwalt was seen leaving port to begin a new phase of sea testing.

Hypersonic missile capability for the USS Zumwalt

The DDG-1000 modernisation is among the most substantial changes in the class’s recent history. Since entering the Pascagoula shipyard in 2023, the ship has been modified to incorporate the Conventional Prompt Strike (CPS) hypersonic weapons launch system. This involves removing the two Advanced Gun System (AGS) guns and fitting four large launch tubes capable of deploying intermediate-range hypersonic missiles. The conversion is designed to make Zumwalt a key long-range strike platform for use against strategic targets, strengthening the US Navy’s deterrence capability.

Alongside the installation of the new launch system, work on the destroyer included structural alterations, combat-system upgrades and improvements to its electrical architecture. These enhancements make use of the powerful integrated propulsion system that distinguishes the class. Its energy capacity is essential to support both the new sensors and the next-generation weapon systems incorporated into the ship’s hull.

Modernisation of the remaining Zumwalt-class destroyers

HII also confirmed that it is carrying out upgrade work and fitting hypersonic missile launch systems aboard USS Lyndon B. Johnson (DDG 1002), the third ship of the Zumwalt class. However, the company provided no further details regarding the schedule for trials or delivery.

Meanwhile, the future of the class’s second destroyer, USS Michael Monsoor (DDG 1001), remains to be decided. Although its modernisation is planned in the same manner as that of the other two vessels, it is still awaiting approval from the US Navy, as well as the availability of the necessary industrial capacity.

Returning to USS Zumwalt, the completion of its first navigation trials after modernisation clears the way for HII to continue with its programme of tests and assessments. These are expected to conclude when delivery to the force is planned, after which the US Navy will conduct its own acceptance trials and operational validation ahead of the ship’s eventual return to service.

Cover photograph used for illustrative purposes.