The US Navy is currently 24 months behind in its efforts to modernise its three Zumwalt-class destroyers to host the "conventional prompt strike" (CPS) hypersonic missile as part of its surface strike mission, the US Government Accountability Office (GAO) revealed in report published on Friday, July 17.
The GAO found that both the Zumwalt-class and CPS efforts face challenges such as: modernisation of class lead ship USS Zumwalt being behind schedule due to unplanned work despite being 94 per cent complete as of January 2026; the ships' unique systems such as radar and combat systems being costly and difficult to sustain and maintain; flight testing of CPS pushed back two years to 2027 due to funding and testing challenges; and quality and production issues that push the missiles' production rate well below the goal of 12 rounds per year.
The GAO said the US Department of Defense (DOD) is planning to invest at least US$50 billion into developing, testing, producing, and fielding CPS capability across several programs. While US Navy and US Army officials told GAO that they coordinate with each other, the services largely manage investment decisions for these programs separately, which contributes to inefficiencies and delays.
The GAO found that the DOD does not have a comprehensive strategy across all programs that would ensure that each program’s investments achieve CPS’s common objectives. Without a comprehensive investment strategy that includes more formal coordination, the army and navy are not well-positioned to make timely and efficient investments in key areas, such as addressing shortfalls on their shared production lines or ensuring the economical sustainment and performance of the DDG 1000.
The navy intends to provide its three Zumwalt-class ships with the ability to strike surface targets. In 2021, the navy decided to add hypersonic CPS missiles—at a planned cost of nearly US$50 million per missile—to the Zumwalt-class destroyers to enable the US to strike valuable, heavily defended targets from a distance with a non-nuclear payload.
To do so, the navy is modernizing the ships to include installing a vertical launch system for CPS missiles. The navy also plans to add the CPS missile system to some Virginia-class submarines while the army is developing its own version of the CPS and is responsible for producing the missile glide body for both services, among other responsibilities.
A US House report includes a provision for GAO to review the navy’s large surface combatant program, including efforts to modify the Zumwalt-class ships for their new mission. This report examines (1) the status of the Zumwalt-class modernization, including CPS development, testing, and integration, and what risks these programs face; and (2) the extent to which DOD has a comprehensive strategy across various programs needed to field the CPS missile capability.
The GAO reviewed relevant navy and army documentation and interviewed navy and army officials and contractor representatives. GAO also visited ship and missile contractor facilities in Mississippi and Alabama.
The GAO is recommending that the DOD develop and regularly review a comprehensive strategy that guides the coordination of investment decisions for delivering CPS capability. The DOD concurred with this recommendation.
