US Navy advances new W93 nuclear warhead for submarine-launched missiles

The US Navy’s W93/Mk7 nuclear weapons program has entered the Engineering and Manufacturing Development (EMD) phase after achieving Milestone B earlier this year, marking a new step toward modernizing the submarine-launched ballistic missile fleet.

In a September 24 announcement, the Navy’s Portfolio Acquisition Executive Strategic Systems Programs (PAE SSP) said the program will now focus on completing the production design and demonstrating that it can be manufactured to meet the service’s requirements.

The W93 warhead and Mk7 reentry body assembly represent the first US nuclear warhead and reentry system program initiated in nearly four decades, the Navy said. Together, they are intended to provide a modern warhead for the US submarine-launched ballistic missile fleet.

W93/Mk7 enters engineering and manufacturing development

The transition into EMD follows the program’s achievement of Milestone B, an acquisition milestone that allows it to advance into this phase of development.

The Navy said the work will focus on completing the production design and demonstrating that the design is producible. The announcement did not disclose a production schedule, cost estimate, or planned deployment date.

Vice Adm. Douglas Williams, director of PAE SSP, said the W93/Mk7 is intended to provide flexibility and adaptability for future warfighter needs while supporting an uninterrupted at-sea deterrent.

Williams also credited collaboration between PAE SSP, the National Nuclear Security Administration (NNSA), and industry partners for accelerating the program’s entry into the next phase.

A new warhead for the submarine-launched nuclear force

The W93/Mk7 program is part of the modernization of the sea-based leg of the US nuclear triad, which relies on ballistic missile submarines to provide a nuclear deterrent.

The Navy’s Strategic Systems Programs is responsible for sustaining the strategic weapon system aboard Ohio-class ballistic missile submarines and supporting the integration of the Trident II D5 Life Extension weapon system on the newer Columbia-class ballistic missile submarines.

The Navy’s announcement describes the W93 warhead and Mk7 reentry body as a combined program. It does not provide detailed technical specifications for either component.

The program is being developed through a partnership between PAE SSP, the NNSA, and associated national laboratories under the interagency Nuclear Weapons Life Cycle process. The collaboration covers design, development, and production.

NNSA Administrator Brandon Williams said the agency is working to modernize the Nuclear Security Enterprise and develop the weapon in coordination with the Navy.

US Navy’s submarine weapons modernization effort

The W93/Mk7 is one of several programs PAE SSP is pursuing to modernize the Navy’s strategic weapons systems.

The office is also developing the Trident II D5 Life Extension 2 strategic weapon system, alongside the nuclear-armed sea-launched cruise missile program, known as SLCM-N, and the non-nuclear Conventional Prompt Strike hypersonic weapon system.

These programs address different capabilities: the W93/Mk7 focuses on the Navy’s nuclear warhead and reentry system, while Conventional Prompt Strike is intended to provide a non-nuclear hypersonic strike capability.

The Navy said the W93/Mk7 program’s latest milestone advances its effort to deliver a modernized capability to the submarine fleet and sustain the sea-based component of the US nuclear deterrent.