The U.S. Navy is converting its Zumwalt-class stealth destroyers into what could become the first U.S. surface warships to deploy hypersonic weapons, replacing the ships’ original gun systems with Conventional Prompt Strike (CPS) weapon tubes. The conversion centers on USS Zumwalt (DDG-1000), where twin 155mm Advanced Gun Systems are being removed to make room for four large-diameter missile tubes. If the program stays on track, the Navy plans to begin shipboard CPS testing in 2027, but schedule slips and technology-maturity questions have drawn scrutiny from both Congress and federal auditors.
A 16,000-Ton Stealth Hull Built for Power
The Zumwalt class was designed from the start around an electrical architecture that most surface combatants lack. At 610 feet and nearly 16,000 tons, these are the largest destroyers in the fleet, yet they operate with a crew of just 186 sailors. Their Integrated Power System generates 78 megawatts through a combination of two main turbine generators, two auxiliary turbine generators, and two propulsion motors rated at 34.6 MW each. That surplus electrical capacity is central to the hypersonic conversion: the ship can route power where it is needed, whether for propulsion, sensors, or weapon-system electronics, without the fixed mechanical gearing found on older hulls.
The original weapons fit included 80 Advanced Vertical Launch System cells and two 155mm AGS turrets. The guns, however, became an expensive dead end after the Navy canceled the precision munitions they were supposed to fire. That left two large, structurally reinforced spaces forward of the deckhouse with no operational purpose, an opening the service is now exploiting for hypersonic integration. The ship’s tumblehome hull and composite deckhouse are designed to reduce radar cross-section, which the Navy says supports survivability in contested environments.
Swapping Guns for Hypersonic Tubes
Shipbuilder HII won a $154.8 million contract to perform the physical conversion at a Mississippi shipyard. The work replaces the twin 155mm gun mounts with four missile tubes, each roughly 87 inches in diameter. Each tube is intended to house CPS launch hardware for hypersonic weapons, though the Navy has not publicly detailed the final at-sea loadout for each deployment. The contract originally targeted completion by September 2025, though the broader CPS program has experienced delays that could affect that window, and the Navy has left room to adjust the schedule as testing data and integration challenges emerge.
Lockheed Martin serves as the prime contractor for CPS integration, overseeing a modular architecture that pairs an all-up-round canister with a payload modular adapter. That design choice matters beyond the Zumwalt class. If the adapter proves interchangeable across different ship types, the Navy could potentially shorten future retrofit timelines for other surface combatants. The service has signaled its intent by stating that it wants CPS tests on Zumwalt in 2027. If that schedule holds and the weapon is declared operational afterward, Zumwalt could be among the first U.S. warships to field a sea-based hypersonic strike capability.
Schedule Slips and Watchdog Warnings
Federal oversight agencies have flagged persistent risk in the CPS timeline. The nonpartisan Congressional Research Service has documented delays in the CPS live-fire demonstration, a milestone that must be cleared before the weapon can be declared operational. Software integration and the maturation of guidance components remain open concerns, and planned modernization windows for the DDG-1000 class depend on those technical hurdles being resolved in sequence. Any further slip in the live-fire test pushes back the entire chain of events, from at-sea testing to initial operational capability, and compresses the time available to train crews and validate tactics before the next budget cycle.
The Government Accountability Office reinforced those concerns in its annual weapon systems assessment, released as GAO-25-107569. That report evaluates schedule, cost, and technology maturity across major defense programs and includes program-by-program assessments of DDG-1000 modernization. While the GAO assessment covers dozens of weapon systems, its inclusion of the Zumwalt hypersonic effort signals that auditors consider the program significant enough to warrant individual tracking. The combination of CRS and GAO attention means Congress has two independent analytical pipelines monitoring whether the Navy can deliver on its 2027 testing goal and whether additional funding, schedule relief, or program restructuring will be needed.
Why Modular Design Shapes the Wider Fleet
Much of the current coverage treats the Zumwalt conversion as a standalone story about a single ship. That framing misses the broader stakes. The modular adapter architecture being tested on DDG-1000 is designed to be platform-agnostic, allowing the same missile canister and interface to be hosted on different launchers with minimal redesign. If Lockheed Martin and the Navy validate the all-up-round concept during 2027 testing, the same weapon package could be installed on other vessels without requiring a full hull redesign for each class. That would turn USS Zumwalt into a proof-of-concept platform whose real value is measured not in 12 missile tubes but in the speed at which the technology spreads across the fleet and how quickly doctrine can adapt to long-range, high-speed strike options.
The risk, however, cuts both ways. A failed or significantly delayed test program on Zumwalt would not just stall one ship; it would cast doubt on the Navy’s ability to field sea-based hypersonics at scale. China and Russia have both pursued their own hypersonic capabilities, and reporting on foreign tests has sharpened concerns about keeping pace in this class of weapons. If CPS integration falters, the Navy could find itself reliant on legacy cruise missiles and ballistic systems at a time when adversaries are experimenting with faster, more maneuverable threats. Conversely, a successful demonstration on Zumwalt would provide a template for rapid follow-on installations, potentially allowing the service to prioritize key theaters and mission sets while spreading the cost and technical risk across multiple hulls and shipyards.
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*This article was researched with the help of AI, with human editors creating the final content.
