Japan to Deploy ASM-3A Supersonic Anti-Ship Missiles This Year

Japan will begin deploying its first ASM-3A supersonic anti-ship missiles on fighter jets this year, marking a shift away from subsonic aircraft-launched anti-ship missiles.

The report comes from Japanese news outlet Jwing.

The Japan Air Self-Defense Force is scheduled to start fielding the new ASM-3A missiles in fiscal year 2025.

The missiles will be mounted primarily on Japan’s F-2 multirole fighters, replacing the older subsonic ASM-1 and ASM-2 models that have been in service since the 1980s.

ASM-3A is considered an interim solution intended to facilitate the transition to a more advanced missile system, ASM-3 Kai, which remains in development.

A Compromise Between Timelines and Capability

Developed by Mitsubishi Heavy Industries for the Japan Ministry of Defense, ASM-3 was designed as a significant upgrade to the country’s aging stockpile of air-launched anti-ship missiles. The primary goals were high speed, survivability, and long-range effectiveness.

The result was a supersonic missile capable of cruising at speeds up to Mach 3 — over 3,700 km/h — powered by a ramjet engine.

However, by the time development concluded, the ASM-3’s relatively short range of 150–200 km was seen as inadequate. To reach targets at that distance, launch aircraft would have to enter enemy interception zones, limiting the missile’s operational value.

In response, the Ministry of Defense shelved the original ASM-3 and opted to produce a modified version, ASM-3A. While maintaining the same external dimensions, ASM-3A features extended range, though official specifications remain classified.

Like its predecessor, ASM-3A is believed to use an onboard radar seeker for terminal guidance. Designers likely reduced the warhead weight and adjusted the missile’s flight profile, potentially favoring high-altitude cruise to improve range.

The Ministry began procuring ASM-3A in 2021 as a stopgap measure ahead of the anticipated deployment of the more capable ASM-3 Kai.

Meanwhile, development of ASM-3 Kai continues. The upgraded missile is expected to feature significantly extended range — possibly beyond 400 km — enhanced navigation, and potentially stealth characteristics.