SerpApi.Org
The U.S. Navy is now two years behind schedule in adding Conventional Prompt Strike (CPS) hypersonic missiles to its three Zumwalt-class destroyers, according to a Government Accountability Office (GAO) report from July 17. The GAO said ongoing delays in ship upgrades, missile production, and testing are holding back the Navy’s goal of launching its first surface ship with hypersonic weapons.
Even with the delay, the USS Zumwalt (DDG 1000) should return to service by September 2026 as the first U.S. Navy ship with hypersonic missile launchers. However, it will not carry any missiles at first because the weapons are still being developed and tested.
Zumwalt upgrade nears completion
By January 2026, the USS Zumwalt’s modernization was 94 percent done. The upgrade swaps out the ship’s two 155 mm Advanced Gun Systems for four large missile launch tubes. Each tube can hold three CPS missiles, so the ship will be able to carry up to 12 hypersonic weapons when the system is ready.
The upgrade has run into technical problems. The GAO reported that when the ship’s 78-megawatt hybrid-electric power system was shut down and restarted for the first time, some equipment failed. Workers also had to remove more cabling than planned to install the new launch tubes, which added extra work and delayed the schedule.
In August 2025, the Navy added 230,000 hours of unexpected work to its contract with Huntington Ingalls Industries, costing $20 million. Because of this, the estimated cost to upgrade all three Zumwalt-class destroyers rose from $1.8 billion to at least $2 billion.
Missile testing and production remain hurdles
The GAO report said the first at-sea flight test of the Conventional Prompt Strike missile has been delayed from 2025 to 2027 due to funding and testing issues.
While the ship upgrades are almost done, missile production is still far behind the Navy’s goal. The GAO found that Lockheed Martin can only make six or seven missiles a year right now, instead of the planned 12 per year.
The Navy’s costs are also going up. The estimated total cost of the CPS program rose from $31 billion for 262 missiles in 2020 to $41 billion for 224 missiles. By April 2026, each missile was expected to cost about $67 million on average.
GAO calls for unified hypersonic strategy
Besides the ship and missile delays, the GAO said the Pentagon lacks a coordinated investment plan for the over-$50 billion Conventional Prompt Strike program. This program covers the Zumwalt-class destroyers, Virginia-class submarines, and the Army’s Long-Range Hypersonic Weapon.
Since each military branch manages its own investments, the report warned there could be “additional delay and inefficient use of taxpayer funds,” the report said.
The Department of Defense agreed with the GAO’s recommendation to create a comprehensive strategy for managing the program across all military branches.
The report also pointed out some recent progress. In April 2025, the Navy completed its first full test of the CPS cold-gas launch system using a land-based launcher at Cape Canaveral Space Force Station in Florida. This was an important step before starting sea-based flight tests.
