Japan is gearing up to initiate one of the most significant naval programs of the coming decade: the design of **a new class of submarines equipped with Vertical Launch Systems (VLS)** for stand-off missiles.
According to a preliminary assessment released by the Ministry of Defense from the Defense Equipment Agency (ATLA), the project officially begins in the fiscal year of 2026 with a **budget of approximately 39 billion yen (about 27 million euros in the current exchange rate) allocated to research and development phase.**
**Technical Challenges**
Integrating a large and complex system like a VLS into the already crowded hull of a submarine presents formidable engineering challenges, which the study aims to **address through an _’optimized total ship design’_,** considering the submarine as a unique and integrated system.
The specific technical objectives initially include the need to limit the reduction of stealthiness, as the addition of the VLS will lengthen the hull, potentially increasing the submarine’s acoustic and magnetic trace. To mitigate this impact, the study will seek solutions through **optimization of the layout and integration of the equipment.**
Secondly, preserving dynamic performances is crucial, as a longer and heavier submarine could be less agile. To this end, upgrades to the propulsion system, such as high-voltage electric motors, will be evaluated to compensate for this potential loss of performance.
Lastly, it is necessary to manage **stability during launch,** as launching a large missile from a submerged submarine can disrupt its trim. Therefore, the study aims to develop weight and stability control technologies, such as compensation systems, to ensure that the submarine can safely launch and maneuver immediately after completing the sequence.
The decision fits into the strategic framework outlined by the **National Defense Strategy** and the **Defense Buildup Program** approved in 2022, emphasizing the need to strengthen the country’s long-range attack capabilities by integrating diversified and hard-to-intercept platforms.
In this context, future VLS-equipped submarines represent a **crucial element to ensure the ability to launch stand-off missiles from high-stealth underwater environments**, thus increasing the resilience and flexibility of the Maritime Self-Defense Force (JMSDF).
The research phase will also be supported by advanced simulations through the **Submarine Concept Evaluation Simulator**, a virtual environment capable of modeling different operational scenarios and testing the behavior of the entire platform under realistic conditions. This choice aims to reduce experimentation costs and speed up the transition to tangible prototypes.
According to experts consulted by the Ministry, there are no viable domestic alternatives, nor any chances of acquiring equivalent technologies from abroad, considered extremely confidential. Therefore, **Japan is tasked with developing the necessary internal know-how to complete the project.**
The program, which will be developed between 2026 and 2029, is considered strategically important for maintaining underwater superiority and for strengthening the country’s deterrent capability.
