Japan to Develop Hypersonic Missile for Submarines

The Japan Ministry of Defense has requested funding in the fiscal 2027 budget to develop a hypersonic missile for submarines.

Kyodo News reported this.

The development of such a missile would be a new program intended to strengthen the strike capabilities of Japan’s submarine fleet.

The official budget request document has not yet been published. However, Japan is already developing a vertical launch system for cruise and ballistic missiles that is planned for use on submarines.

The new program comes as Japan Ministry of Defense is seeking a record budget to finance the Self-Defense Forces. The request for ¥8.9 trillion, or about $60.1 billion, is intended to support the development of new methods of warfare.

Despite the budget request, development of hypersonic weapons, including hypersonic cruise missiles, has been underway since 2019. In December 2025, Japan Ministry of Defense announced that it was beginning mass production of new hypersonic guided missiles to strengthen the country’s long-range defense capabilities.

Although the full development cycle is not expected to be completed until fiscal 2031, Japan’s military command has decided not to wait until then. Following successful interim research results from work that began in 2023, Japan decided to begin mass production.

Read also: “Japan’s Missile Era: Short- and Medium-Range Ballistic Missiles.”

In June 2026, Militarnyi reported that development of the vertical launch system would continue from 2026 to 2029, with total research costs estimated at about ¥3.9 billion ($24.8 million).

Engineers are developing a vertical launch system capable of launching various types of missiles, including HVGP ballistic missiles, specifically the naval variant, as well as cruise and hypersonic missiles.

According to the officially released rendering, the system will have seven to eight cells in each launch module for storing missiles. A submarine will be able to carry two to three such systems, with a total of 14 to 24 cells.

Meanwhile, in October 2025, Japan Ministry of Defense awarded a contract for the mass production of new cruise missiles for surface warships and submarines.

The missiles are 12SSM-ER missiles, which will become the Japan Self-Defense Forces’ standardized primary long-range weapon for the Navy, Air Force and Ground Self-Defense Force.