Japan Reveals Details About Next-Generation Railgun and High-Energy Laser Weapons Projects

The Japanese Ministry of Defense's Acquisition, Technology, and Logistics Agency (ATLA) has revealed details on both its electromagnetic (EM) railgun and high-energy laser weapons projects.

ATLA officials listed these projects as two of the agency’s top research and development priorities at the Defense Technology Symposium 2023, which was held by the agency in Tokyo from November 14 to 15.

They said Japan will intensify efforts to develop advanced defense technologies – such as EM railguns and laser-based weapons – as “game changers” that will completely change conventional combat amid concerns by Tokyo of the growing airborne threats posed by China, North Korea, and Russia.

With the advent of these cutting-edge weaponries, ATLA particularly aims to enable Japan’s Self-Defense Forces (SDF) to intercept multiple missiles – and/or incoming hostile unmanned aerial vehicles (UAVs) – simultaneously, while lowering costs compared with current technologies.

Railguns use electrical energy to fire hypersonic bullets without using traditional gunpowder. In previous experiments conducted by ATLA, a bullet fired from a gun barrel with a total length of 6 meters and a diameter of 40 mm recorded an initial speed of 2,297 meters per second, close to Mach 7 (seven times the speed of sound).

ATLA officials pointed out the railgun’s initial velocity exceeded the speed of a tank gun, one of the fastest conventional artillery guns. Tank guns fire projectiles at a velocity of about 1,750 meters per second.

An EM railgun can also be fired in rapid succession and costs less than regular interceptor missiles, according to ATLA. Expectations are particularly high for this weapon as a next-generation interceptor to counter hypersonic missiles being developed by China, North Korea, and Russia.

On October 17, ATLA announced that it had accomplished a ship-board firing test of a railgun for the first time in the world. The test was carried out on the Japan Maritime Self-Defense Force’s sole Asuka-class research ship, JS Asuka.

There have been many research and development projects around the world for railguns, but there are no practical examples yet. The U.S. Navy, which had been developing a railgun for more than a decade, gave up on the development in 2021. Although tests on land were successful, it was not possible to develop a ship-mounted version due to technological challenges.

The Japanese Defense Ministry allocated 6.5 billion yen ($43.5 million) in fiscal year 2022 and 16 billion yen in fiscal year 2023 respectively to “conduct research on future railguns that can fire bullets at high initial velocity in order to deal with various aerial threats.” In late August, it requested 23.8 billion yen for the fiscal year 2024 budget for future railgun research. Japan Steel Works, Ltd. is mainly involved in this railgun project.

ATLA said it intends to steadily work toward the early practical use of railguns to accelerate the strengthening of Japan’s defense capabilities.

Meanwhile, on high-energy laser weapons systems, ATLA officials pointed out two main advantages. The first is that as long as electrical power is supplied, there is no running out of ammunition. Because a laser is a type of light, forces can continue firing without depleting ammo stocks. That also has the advantage of lowering costs, as no projectiles are expended to intercept the target.

Kawasaki Heavy Industries (KHI) and Mitsubishi Heavy Industries (MHI) are both exploring this technology.

Research and prototype work by KHI has been underway since fiscal year 2018, creating a laser system with an output of 100 kilowatts that can destroy mortar shells and small unmanned aerial vehicles (UAVs). The prototype was completed in February 2023, successfully detonating mortar shells placed on the ground.

Meanwhile, research and prototype production by MHI began in fiscal year 2021. This laser system has an output of 10 kilowatts that can shoot down small unmanned aircraft. The company conducted repeated demonstration tests on Tanegashima in Kagoshima prefecture, an islet south of Japan’s southernmost main island, and succeeded in shooting down a drone from 1.2 kilometers away.​

“We will proceed with the research step by step, put it into practical use as an equipment system, and improve our technological capabilities to realize a future laser-based anti-missile system,” ATLA said.

A common challenge for railguns and high-power laser systems is to miniaturize the power supply equipment. Both systems require large amounts of electricity, so a large-capacity power supply is essential. The challenge is to reduce the size of the device so that it can be installed on ships and other vessels.

According to ATLA, the specifications of the railgun’s power supply include a charging energy of 5 megajoules and a charging voltage of 8.5 kV. The prototype device is the size of four 20-foot containers.

On the other hand, the laser system prototype device, manufactured by KHI has the size of two 40-foot containers.

In other words, the size of both equipment systems is still quite large. In order to downsize the equipment, it is necessary to downsize the power supply equipment.