Questions have been raised over the feasibility of a government plan to deploy radar and anti-missile systems on a vessel or similar facilities, as a replacement for the scrapped Aegis Ashore land-based missile defense system.
The government hopes to deploy the alternative defense system on the sea instead of on land, as its plans to set up Aegis Ashore systems in the prefectures of Akita and Yamaguchi were scuttled after they met with strong opposition from local residents.
The alternative defense system is expected to use U.S. aerospace giant Lockheed Martin’s SPY-7 radar system, which Japan initially planned to use in its Aegis Ashore system.
The SPY-7, currently under development, derives from a ballistic missile warning radar system set to be used in Alaska for protecting the U.S. mainland. It is built for use on land.
As land-based radar systems consume a large amount of electricity, converting the SPY-7 to be deployable on a ship may require changes such as making it smaller in size, according to a government source.
As such changes could affect the detection ability of the radar system, costly, time-consuming trial tests would be necessary.
There are also issues regarding the operation of the system. The government is considering deploying the alternative missile defense system on a maritime platform similar to an oil rig, or on a ship converted from a commercial vessel, but such options lack agility and may be heavily impacted by weather conditions.
There is also the issue of how the facility would be used in peacetime.
Regarding the idea of building a warship exclusively for the defense system, the option the government sees as most feasible, there are concerns about limitations to the activities it could perform during peacetime, as the envisaged ship would not be equipped with anti-submarine and anti-ship missile capabilities in order to save costs and manpower.
“If the vessel’s protective capability is low, its everyday patrols will be limited to those in coastal areas, and that is inefficient amid a lack of manpower,” a senior official of the Self-Defense Forces said.
While the Defense Ministry is intent on using the SPY-7, the U.S. Navy plans to equip its new Aegis warship in 2024 with the SPY-6 radar system developed by U.S. aerospace giant Raytheon.
“It would be more proven and reasonable to review (the Maritime Self-Defense Force’s) destroyer fleet and increase Aegis ships with SPY-6 radars” than to deploy the newer radars, if the alternative defense system is to be deployed at sea, one MSDF source said.