Japan’s Ministry of Defense reported that, within the framework of the program for the new ASEV (Aegis System Equipped Vessel) destroyers, a series of target detection tests were recently carried out using the AN/SPY-7 radar, the sensor that will equip these future units to be incorporated into the Japan Maritime Self-Defense Force. The trials, conducted on U.S. territory with the support of American assets and infrastructure, represent a new milestone in the development and integration of one of the program’s most critical components
Going into further detail, the official statement notes that the tests were conducted on May 17 and 19 of this year, as part of a land-based testing program that has been underway since September 2025. During these trials, key system capabilities were evaluated, including search, detection, identification, tracking, and target management, using targets launched from U.S. test facilities.
All data collected will now be analyzed to continue the system validation process, marking a critical stage prior to its future integration aboard the new vessels.
A key system for Japan’s missile defense
The AN/SPY-7(V)1 radar, developed by Lockheed Martin, will serve as the core of the AEGIS system to be integrated into the ASEV destroyers, which are primarily designed for air defense and ballistic missile interception missions.
Based on active electronically scanned array (AESA) radar technology, it offers substantial improvements in range, sensitivity, and processing capability compared to previous generations, enabling the detection and tracking of multiple threats simultaneously, including ballistic missiles at different phases of their trajectory. It should be noted that the selection of this radar is closely tied to Japan’s requirements to strengthen its defense architecture in response to the growing missile capabilities of China and North Korea.
Progress in the ASEV destroyer program
The future ASEV destroyers were conceived as a replacement for the canceled AEGIS Ashore system (land-based), transferring those capabilities to naval platforms. According to Tokyo, construction of the units began in 2024, with the first ship expected to enter service by late 2027, while the second is scheduled for 2028.
In line with this timeline, in January 2025 Japan received the first SPY-7 radar antenna, marking one of the initial milestones in the integration of the systems that will make up these new units. Likewise, in September 2024 the construction order for the second destroyer was formalized, consolidating the program as one of the pillars of Japan’s missile defense in the medium term.
Regarding its armament, the new Japanese destroyers are expected to be equipped with a 5-inch (127 mm) Mk-45 (Mod.4) main gun, as well as SM-3 Block IIA, SM-6, Tomahawk, and Type 12 (SSM) missiles.
Progressive integration with U.S. support
Finally, from a broader and more strategic perspective, part of the testing conducted in the United States reflects the cooperation between Japan and the U.S. in defense matters, particularly in the development and integration of the AEGIS system. Moreover, the land-based testing process allows systems to be validated in a more controlled environment prior to their final installation, reducing technical risks and ensuring interoperability with other U.S. systems deployed in the region.
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