The SSN-AUKUS programme – the trilateral submarine project that will deliver next-generation nuclear-powered attack submarines for the UK and Australia – has had a productive few months. Three significant developments have emerged since the start of the year, each adding substance to what has sometimes felt like a programme long on ambition and short on concrete progress.
Vertical launch systems confirmed
In March 2026, Naval News reported that Royal Navy SSN-AUKUS submarines will be fitted with vertical launch system (VLS) tubes – a significant capability addition that had not previously been confirmed. VLS tubes allow a submarine to carry a broader and larger magazine of weapons, including Tomahawk land-attack cruise missiles and potentially future hypersonic weapons, without the constraints of torpedo tubes.
The Royal Navy’s current Astute-class submarines carry Spearfish torpedoes and can fire Tomahawk missiles through their torpedo tubes, but lack dedicated VLS. Adding VLS to SSN-AUKUS brings the Royal Navy’s future attack submarines closer to the capability level of the US Navy’s Virginia-class, with which SSN-AUKUS shares technologies and design heritage. It is a meaningful upgrade in strike depth and magazine size.
Rolls-Royce opens new reactor manufacturing facility
In July 2026, Rolls-Royce Submarines announced the opening of a new manufacturing facility dedicated to SSN-AUKUS nuclear reactor production. The investment strengthens the allied capacity to build and sustain nuclear-powered submarines at scale – something that has been identified as a critical industrial bottleneck in all three AUKUS nations.
The reactor is among the most technically demanding components of any nuclear submarine, and building the manufacturing capacity to produce them at the rate required by the programme – up to 12 reactors for the Royal Navy alone, plus reactors for Australian boats – requires sustained industrial investment over many years. The Rolls-Royce facility represents a meaningful step toward that capacity, and its opening confirms that the programme is moving beyond paper commitments into physical infrastructure.
The Defence Investment Plan commits to 12 boats
The June 2026 DIP confirmed the UK’s commitment to acquiring up to 12 SSN-AUKUS submarines for the Royal Navy, with construction of the first boat beginning next year. The class is expected to enter service with the Royal Navy in the late 2030s, followed by the Royal Australian Navy in the early 2040s.
Twelve boats would represent the largest Royal Navy submarine fleet in decades, and the most significant commitment to undersea warfare capability in a generation. Current Astute-class production has delivered seven vessels; building twelve SSN-AUKUS boats would more than replace the Astute fleet at a significantly higher capability level.
The near-term picture
Before SSN-AUKUS arrives, AUKUS operations are already bearing practical fruit. HMS Anson completed a maintenance period in Western Australia in 2026, the first of the Astute class to do so at HMAS Stirling, establishing the basing and maintenance infrastructure that will eventually support the full AUKUS rotation of UK and US submarines in Australian ports.
The Dreadnought-class ballistic missile submarines – the successor to Vanguard and carrier of the UK’s nuclear deterrent – remain on a parallel track. SSN-AUKUS sits alongside rather than instead of that programme. The combined commitment, detailed in the DIP as more than £63 billion over four years for submarines and nuclear deterrence, represents the single largest element of the UK’s defence investment by a considerable margin.
Whatever debates surround other aspects of the DIP, the commitment to undersea capability is unambiguous.
