UK, US, set to seal vertical launcher deal for SSN-AUKUS submarine

A model of SSN-AUKUS on display at DSEI 2025. (Janes/Neil Dee)

The UK government is closing in on a US Foreign Military Sales (FMS) deal valued at an estimated USD1 billion covering the design and integration of vertical launcher systems (VLS) for the SSN-AUKUS nuclear-powered attack submarines being developed for the UK Royal Navy (RN) and the Royal Australian Navy (RAN).

Revealed in a 20 March Department of State notification to Congress, the FMS case covers submarine combat and weapon systems, technical support, US and UK embedded personnel, and associated training. It builds on an original FMS case covering non-recurring engineering support and US equipment design integration activity.

Being jointly procured under Pillar 1 of the trilateral AUKUS security agreement, SSN-AUKUS is intended to provide the RN and the RAN with a common SSN design that will be built in both countries. Capitalising on concept design activity previously undertaken as part of the UK's national SSN(R) programme, the SSN-AUKUS submarine will incorporate technology inputs from all three AUKUS nations, including US-developed propulsion plant systems and components, a common VLS, and weapons.

The VLS is expected to be common with, or a close derivative of, the mid-body Virginia Payload Module (VPM) being incorporated in the US Navy's latest Block V Virginia-class SSNs. The VPM consists of four large-diameter vertical tubes, each of which hosts seven cells for strike length weapons.

According to the notification to Congress, the latest UK FMS request covers the procurement of technical assistance supporting the design and development of AUKUS-specific vertical deployment tubes. It also includes common weapon launchers, multiple all-up-round canister support service modules, network input output units, and servers and switches with custom electronics. These are specific components of the US Navy's Submarine Warfare Federated Tactical System.