Development work of this new missile began in 2019 and is set to be completed in the 2030s. ATLA is currently in the development phase of the scramjet engine along with local company Mitsubishi Heavy Industries which won a contract for the prototype engine research.
The missile aims to be powered by a Dual-Mode Scramjet engine (DMSJ), a combination of ramjet and scramjet (supersonic combustion ramjet) engines, to fly at a wide range of speeds, including hypersonic speeds of Mach 5 or higher.
Ramjet + Scramjet propulsion
The scramjet engine is expected to have high engine efficiency in a wide range of speeds, from Mach 5 to 15, because the air inhaled from the intake is compressed and combusted at supersonic speed when the missile flying at Mach 5 or higher. That means that the scramjet engine would need to be accelerated the missile to hypersonic speeds to operate, and that would require acceleration by a rocket booster. However, a large rocket booster would be required to accelerate to hypersonic speeds, which would increase the overall length of the missile, including the booster. Therefore, ATLA planned to combine the capabilities of the ramjet engine, which operates efficiently in the Mach 3 to 5 speed range(supersonic speed), with the scramjet engine (DMSJ) to reduce the proportion of the rocket booster. In this way, the rocket booster only needs to accelerate the missile to supersonic speed, and from there, the ramjet engine accelerates the missile to hypersonic speed, which then activates the scramjet engine to cruise.
ATLA is now working with Japan Aerospace Exploration Agency (JAXA) to realize the DMSJ:
A “game changer”
According to the ATLA, the hypersonic guided missile can cruise at high altitudes at hypersonic speeds while maneuvering, making it difficult for enemy air defense systems to intercept it. This is because the missile flies at an altitude higher than that of a typical lower level air defense system and lower than that of an upper level air defense system, and further altering the flight route makes it difficult to predict the point of intercept, making it difficult for existing air defense systems to respond it. That’s why ATLA calls the missile a “game changer”.
According to documents released by ATLA, the combined guidance system of satellite and inertial navigation will be used to guide the hypersonic guided missile. In addition, radio and lightwave image seekers will be used to identify targets, and this missile will be capable of all-weather operations. The missile is expected to be capable of carrying a penetrating warhead to destroy the flight decks of enemy aircraft carriers and a high-density Explosively Formed Penetrator (EFP) warhead to suppress enemies on the ground.
JSM, LRASM & ASM-3 anti-ship missiles for JASDF
The hypersonic guided missile is ground-launched, but under current plans, the Japan Air Self-Defense Force (JASDF) will deploy three different types of modern anti-ship missiles:
- the Joint Strike Missile (JSM) for the F-35,
- the Long Range Anti-Ship Missile (LRASM) for the modernized F-15J/DJ fleet,
- the extended-range ASM-3 (ASM-3ER: tentative name in this article) for the F-2
Advantages of fielding various anti-ship missile types
The main reason why the JSDF deploys multiple types of anti-ship missiles is to ensure that the combination of the characteristics of each missile can break through enemy air defense systems. For example, the JSM has the advantage of being hard to detect by enemy radar through sea skimming, but its range is not very long. Also, the LRASM has a long range of about 800 km, but its flight speed is not as fast as subsonic speed. In addition, ASM-3ER will break through the enemy’s air defense system at the speed of about Mach 3, but still the range does not reach far to the LRASM of subsonic speed. However, if they are operated in combination, the enemy will have to deal with each missile with different characteristics, which will place a heavy load on their air defense systems. If a hypersonic guided missile, which flies at high altitude at high speed, is added to this, the probability of the missile hitting an enemy ship becomes extremely high.
It can be said that the JSDF is steadily advancing its countermeasures with the future development of the PLAN in mind.