GAO Audit Digs Up Delays and Overruns in Navy's Hypersonic Missile Program
The Navy's three Zumwalt-class destroyers have had a hard time finding a place in the fleet, and are now two years behind schedule on a planned retrofit project to install launch tubes for the Conventional Prompt Strike (CPS) missile - a weapons system that is itself encountering issues, according to the Government Accountability office.
The U.S. Navy's futuristic Zumwalt-class destroyers were originally built to carry two specialized cannons for long range shore bombardment, designed for an earlier era with less near-peer competition and a more permissive threat environment. When the number of ships in the class was cut back from 32 to three due to cost overruns, the cost per round of manufacturing the specialized ammunition for the deck guns rose to an impractical $800,000-$1 million per shot. The production run for these costly high-speed shells was canceled, making the guns unusable.
Recognizing that the ships could be put to better use, the Navy is refitting the high-end Zumwalt-class with the high-end weapon of the 2020s: hypersonic missiles. Aboard first-in-class USS Zumwalt (DDG 1000), Ingalls Shipbuilding has replaced the twin 155mm Advanced Gun Systems on the foredeck with four cells for the Conventional Prompt Strike missile system, each cell containing a pack of three hypersonic missiles. Similar modifications are under way for DDG 1001 and 1002.
The yard period involves multiple modifications: in addition to the significant structural work forward of the wheelhouse, contractors are removing obsolete computer parts, increasing the berthing capacity, moving the air intakes to reduce ingestion of exhaust gases, upgrading shipboard software, and converting ballast tanks into fuel tanks to extend the ships' range. USS Zumwalt's CPS integration is expected to be ready for flight testing in FY2027, and the missile will then transition to low-rate production for the other two Zumwalt hulls and other platforms.
However, the program has challenges ahead, GAO found. The schedule for retrofits has slipped for all three hulls, including DDG 1001, which has yet to begin the process. Unplanned work to install more cabling, fix complex electrical systems, and delays in funding contributed to setbacks.
The platform is also burdened with preexisting reliability issues related to its complex integrated power system, the centerpiece of the Zumwalt design. The IPS provides power from generators to the main propulsion, ships' systems, and (in the future) any electrically-powered weapons systems like lasers or electromagnetic railguns. "Numerous" serious casualties affecting the IPS have occurred over the years, and some repairs require a three-month lead time to procure parts. For sustainment of the systems on DDG 1000 and 1001, the Navy has been cannibalizing parts from DDG 1002, delaying the latter ship's full activation.
One of the biggest delays, though, has been with CPS itself. In June 2025, testing "anomalies" for the missile system set back DDG 1000's first flight tests for CPS until 2027 - driven in part by funding reductions that restricted the number of available missiles for testing.
That bottleneck could persist, GAO found, as the missile is turning out to be harder to make than expected. "Navy data indicate that the contractor facility operations are not currently able to meet demand," GAO said. "Specifically, the facility is currently capable of producing a maximum of six to seven rounds a year out of the 12 rounds per year necessary to stabilize production."
Issues include problems with outer coating application; excessively complex work instructions for production-line workers; incomplete parts kits for missile assembly; high workforce turnover; inadequate controls on parts and materials; poor adherence to quality assurance. Navy program managers have little power to order improvements to the production process because of the terms of the procurement contract, which forbids "co-direction" of the work, according to GAO. Meanwhile, coordination with the Army - which is buying its own set of CPS missiles, and has oversight over several key production steps - is lackluster, the agency says.
The CPS capability comes at a price. The Navy estimates a total lifecycle cost of $41 billion for 224 individual missiles and related launch infrastructure, equating to roughly $180 million per round over the system's full lifespan. This figure includes a unit price of $67 million per missile, roughly 20 times more than the unit price for a stealthy Long Range Antiship Missile (LRASM). Poor planning and coordination could raise that price, GAO cautioned.
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"The Navy and the Army do not have a comprehensive strategy to guide CPS portfolio investments in a way that facilitates effective and efficient allocation of funding to achieve the capability envisioned in the services’ respective plans. Without such a strategy, the Navy and the Army create the potential for both additional delay and inefficient use of taxpayer funds," GAO concluded.
