The U.S. Navy is 24 months behind schedule in modernizing its three Zumwalt-class destroyers to carry the Conventional Prompt Strike (CPS) hypersonic missile, the Government Accountability Office (GAO) said in a report released July 17.
USS Zumwalt (DDG 1000) was 94% complete as of January and is expected back in service by September as the first U.S. warship equipped to fire hypersonic weapons. Its four launch tubes, which replaced the ship’s two 155mm Advanced Gun Systems and hold three missiles each, will return to sea empty. The first at-sea flight test has slipped from 2025 to 2027 over funding and testing challenges.
Lockheed Martin’s production facility can build six to seven missiles per year against a goal of 12, GAO found. The Navy’s cost estimate has grown from $31 billion for 262 missiles in 2020 to $41 billion for 224, an average of roughly $67 million per round as of April.
The first full shutdown and restart of Zumwalt’s Integrated Power System, a hybrid-electric plant generating 78 megawatts, produced equipment failures, and the contractor removed more cabling than planned during launch tube installation.
The Navy added 230,000 hours of unplanned work worth $20 million to its Huntington Ingalls contract in August 2025, and the three-ship upgrade estimate rose from $1.8 billion to at least $2 billion.
GAO also found the Pentagon lacks a unified investment strategy for the CPS portfolio, a more than $50 billion effort spanning the Zumwalt class, Virginia-class submarines, and the Army’s Long-Range Hypersonic Weapon.
The services manage those investments separately, creating the potential for “additional delay and inefficient use of taxpayer funds,” the report said. The department concurred with the recommendation.
The Navy completed its first successful end-to-end test of the CPS cold-gas launch system in April 2025 from a land-based launcher at the Cape Canaveral Space Force Station, Florida.
