US-Japan Announce Counter-Hypersonic Missile Collaboration

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The two nations confirmed their collaboration on a counter-hypersonic missile system called the Glide Phase Interceptor (GPI) Cooperative Development program, meant to help Japan defend itself from China’s growing threat.

Japan’s current existing anti-missile systems are mainly built to counter intercontinental ballistic missile threats, which are launched at high angles into space and can be intercepted by specially designed missiles while re-entering the Earth’s atmosphere.

Japan currently relies on SM-3 missiles and Patriot PAC-3 surface-to-air guided missiles, which both track and destroy threats upon reentry into Earth’s atmosphere. However, analysts have pointed out that these systems may not be effective in countering hypersonic threats because they are faster and more agile than ballistic missiles (which travel in a parabolic path through and out of the atmosphere).

According to Interesting Engineering, hypersonic missiles’ characteristics make them harder to detect and track, with some experts believing that they are difficult to intercept unless they are close to the point of impact, where they may be most vulnerable. This is why the two nations will collaborate on developing a new GPI interceptor capable of changing trajectory to respond to high-speed projectiles in low orbit, which will intercept hypersonic projectiles before they enter the atmosphere rather than during their terminal glide phase.

It was reported that the purpose of the counter-hypersonic interceptors will be to intercept the hypersonic glide vehicle right before it enters the atmosphere. The Space Development Agency has contracted L3Harris Technologies and Northrop Grumman to develop satellites to track hypersonic vehicles in low Earth orbit, 28 satellites initially and 100 in total.

This collaboration between the US and Japan is likely meant to counter China’s advancements in the field of hypersonic missiles. The nation seems to be extremely advanced when it comes to developing, testing, and deploying hypersonic weapons, which intimidates the US and the Indo-Pacific region.