TOKYO -- Japan's Ministry of Defense is putting serious research and development resources into railguns, a hitherto science fiction weapon that fires projectiles very fast, very far, and at a high rate using electromagnetic power rather than gunpowder.
Some 6.5 billion yen (around $56 million) was allocated to the railgun project in the government's initial fiscal 2022 budget proposal. With China and North Korea developing difficult-to-intercept hypersonic weapons, will Japan succeed in making the weapon part of its air defenses?
"Our one hope is a prototype weapon called a railgun. It shoots a steel projectile at Mach 7." Shortly after these words are uttered, a railgun built onto a U.S. military guided-missile destroyer fires a hypersonic round that cleaves through a giant robot trying to destroy one of the Egyptian pyramids. So goes one of the scenes in the climax of sci-fi action film "Transformers: Revenge of the Fallen."
With a railgun, an electroconductive projectile is loaded between two prongs also made from electroconductive material. A very strong electric current is then fed up one rail, through the projectile or an armature holding it, and then back down the other rail, creating a strong magnetic field that launches the bullet-like projectile out of the gun at tremendous speeds.
The Ministry of Defense allocated 1 billion yen (about $8.64 million) to the technology in the fiscal 2016 supplementary budget, and built a prototype. The aim is a weapon that can fire a projectile at 2,000 meters per second or more, which is about Mach 6 and above the 1,700 m/s of a tank's main gun. According to the Acquisition, Technology & Logistics Agency (ATLA), speeds of 2,297 m/s have been recorded in trials.
The ministry is doing railgun research because countries around Japan are developing hypersonic weapons. These travel at more than five times the speed of sound, making them hard to intercept and, according to observers, perhaps impossible for Japan's missile defenses to bring down.
U.S. Joint Chiefs of Staff Chairman General Mark Milley said in an October 2021 interview with U.S. media that China had in the summer of that year test-fired a hypersonic weapon. In September 2021, the Korean Central News Agency reported that North Korea had test-fired a Hwasong-8 hypersonic missile developed by the country's Academy of National Defense Science. At the end of 2019, Russia began putting its hypersonic Avangard missiles into service.
According to the ATLA, U.S. research shows railguns have a potential range of about 100 to 180 kilometers. The Imperial Japanese Navy battleship Yamato's 46-centimeter main guns had a maximum range of around 42 kilometers, meaning a railgun has around the same range as a missile. Sustained fire is also possible, and the weapon could be used against an attack by multiple missiles. It is expected to have applications in ground, sea and air battles, and some view it as a military "game-changer."
But there are numerous development hurdles. The ATLA says the U.S., the leader in railgun research, has paused work on the technology. It appears they decided it didn't offer effects greatly different from that of missiles and other technologies, and that the work didn't justify the cost. A source close to the Japanese government said, "We can't rely on the U.S., which has turned to regular warheads. Japan will be at the forefront of development."
Railguns are also extremely power-hungry, requiring 25 megawatts to fire. Where this energy will come from is a major issue. Furthermore, the high heat produced when firing the weapon presents maintenance problems, including wear on the rails from repeated firings.
From fiscal 2022, the Ministry of Defense will push ahead with research into energy efficiency and high-speed firing technology, with an aim to begin deploying the weapons as soon as fiscal 2028. But some in the ministry have expressed concerns, including that they "don't know whether it will run properly. Can it reliably hit targets moving at ultrafast speed?"
(Japanese original by Shu Hatakeyama, Political News Department)