W93 Nuclear Warhead

History

The W93 is a United States submarine-launched nuclear warhead under development for the sea-based leg of the U.S. nuclear deterrent. It is being developed together with the Mk7 reentry body, which carries the warhead through atmospheric reentry after release from a submarine-launched ballistic missile.

The W93/Mk7 effort is the first United States nuclear warhead and associated reentry system program initiated in nearly four decades. The program is intended to provide a modern warhead for the U.S. submarine-launched ballistic missile fleet while maintaining continuity of the sea-based strategic deterrent.

The National Nuclear Security Administration first referred to a future Next Navy Warhead in fiscal year 2020 planning. In fiscal year 2021, Congress authorized and appropriated initial funding that included $53 million for Department of Energy and National Nuclear Security Administration work and $32 million for Department of Defense and Navy work on the warhead and its Mk7 reentry system.

Development

The W93 is being developed through cooperation between the U.S. Navy's Strategic Systems Programs organization, the National Nuclear Security Administration, Department of Energy national laboratories, and supporting industry. The nuclear warhead and its reentry body are being developed under the interagency nuclear weapons life-cycle process.

In 2026, the W93/Mk7 program achieved Milestone B and entered the Engineering and Manufacturing Development phase of the Defense Acquisition System. This phase concentrates on completing the production design and demonstrating that the system can be manufactured in a form that meets Navy requirements.

The available program information describes the W93 as a new warhead program rather than a life-extension variant carrying an existing W-number. Its nuclear design is planned to use previously nuclear-tested design concepts or components, allowing development without a new nuclear explosive test. Detailed information about the nuclear package, yield, dimensions, mass, and internal configuration has not been publicly defined in the supplied material.

Public planning descriptions place future deployment in the 2030s, with 2034 identified as an intended introduction point in some program descriptions and other planning material describing deployment by 2040. The exact production and fleet-integration schedule therefore remains subject to program development and acquisition decisions.

Design

The W93 is designed as a submarine-launched strategic nuclear warhead. It is paired with the Mk7 reentry body, the aerodynamic shell that protects and carries the warhead during atmospheric reentry. The W93 warhead and Mk7 assembly together form the new reentry system being developed for the U.S. submarine-launched ballistic missile force.

The program is intended to incorporate modern safety and security features. Available descriptions indicate that improved safety measures are expected to include insensitive high explosives. The design is also intended to use previously tested nuclear technology rather than requiring a newly tested nuclear explosive design.

The W93 has been associated with the future modernization of the U.S. submarine-launched nuclear stockpile. Existing W76 and W88 warheads remain in service and have undergone separate modernization programs, while the precise long-term replacement sequence and allocation of W93 warheads among submarine-launched ballistic missile forces are not fully defined in the supplied information.

Mk7 reentry body

The Mk7 is the reentry body developed in conjunction with the W93. Its role is to house the nuclear warhead and provide the structure and aerodynamic protection required for atmospheric reentry. The United Kingdom is developing its own future submarine-launched warhead in parallel and is expected to use the Mk7 reentry body while sharing some non-nuclear components with the W93 program.

Program status

As of September 2026, the W93/Mk7 program is in Engineering and Manufacturing Development. The current work focuses on completing the production configuration and proving that the design can be manufactured to meet Navy requirements. The W93 is therefore a development program and is not yet an operational warhead.

Specifications (W93)

General characteristics

• Type: Submarine-launched nuclear warhead
• Country of development: United States
• Associated reentry body: Mk7
• Development organizations: U.S. Navy Strategic Systems Programs and the National Nuclear Security Administration, with Department of Energy national laboratories and industry participation
• Development status: Engineering and Manufacturing Development phase as of 2026
• Intended platform: United States ballistic missile submarines
• Nuclear design basis: Planned use of previously nuclear-tested design concepts or components

Safety features

• Explosive safety: Improved safety features are planned, including the expected use of insensitive high explosives