Japan to Field Dual-Role ASM-3ER Missile in 2027

Japan will begin mass production of the ASM-3ER supersonic missile in fiscal year 2027. The Ministry of Defense revealed in its FY2027 budget request that the anti-ship weapon will also be adapted for an air-to-air role to engage high-value airborne targets.

The ASM-3ER is a long-range, air-launched anti-ship missile developed by Japan's Acquisition, Technology & Logistics Agency (ATLA). It has a range exceeding 400 kilometers. Mitsubishi Heavy Industries manufactures the missile, which uses an integral rocket ramjet propulsion system to fly at speeds over Mach 3.

Development and Capabilities

The missile's development traces back to the ASM-3 program, which began full-scale development in FY2010 as a replacement for older missiles. Japan decided not to field the original ASM-3 due to advancements in Chinese naval air defense. The extended-range ASM-3ER retains the ASM-3's dimensions but incorporates improvements like weight reduction.

For guidance, the ASM-3ER uses an active/passive radar seeker. Its passive mode can detect hostile radar emissions. A key feature for its new air-to-air role is a satellite datalink, allowing it to receive in-flight target updates. This capability is not present on the earlier ASM-3 or interim ASM-3A variant.

The New Air-to-Air Mission

The Ministry of Defense stated that adapting the ASM-3ER for air-to-air engagements will require only software modifications, with no hardware changes needed. Mass production is still scheduled to begin in FY2027, with operational service expected in FY2030.

When used against airborne targets, the missile's effective range could be greater than its stated 400 km anti-ship range. Flying at high altitude reduces drag. The ministry linked the missile's development tests with the Japan Aerospace Defense Ground Environment (JADGE) network. This could allow an F-2 fighter carrying the missile to engage targets spotted by other platforms, like E-767 AWACS aircraft.

However, the ASM-3ER is likely to be more expensive than standard air-to-air missiles. Available stocks will also be limited as the missile fulfills its primary anti-ship mission. According to the MOD, it is therefore likely to be reserved for engaging high value airborne assets such as enemy airborne early warning and control aircraft and aerial refueling tankers.

Integration and Broader Context

The Japan Air Self-Defense Force will operate the ASM-3ER from its F-2 fighter aircraft. From FY2027, the service also plans to field upgraded F-2s capable of launching the air-launched variant of the improved Type 12 Surface-to-Ship Missile, which has a range of about 1,000 km.

This combination will give the F-2 a formidable anti-ship strike capability. The doctrine of using a supersonic missile against high-value air targets mirrors European developments, such as MBDA's STRATUS RS missile under the FC/ASW program.