Japan is developing a hypersonic anti-ship missile, a weapon that can cruise at high altitudes and could pose a threat to Chinese aircraft carriers in the East China Sea. The Ministry of Defence has said it would be a hyper velocity gliding projectile (HVGP) and it planned to deploy an early version of the missile in 2026, followed by an enhanced version after 2028. The planned missile would be able to travel at five times the speed of sound, meaning it would be a hypersonic weapon. With such a missile in service, Japan would be the fourth country in the world armed with hypersonic gliding technology, after China, Russia and the United States. The technology allows a missile to glide at high speed in the upper atmosphere – a weak spot for air defence systems – and to follow complex trajectories, making it difficult to intercept with existing anti-missile shields.
日本は超音速対艦ミサイルを開発しているが、これは高高度での巡航が可能で、東シナ海の中国の空母に脅威を与える可能性がある。 防衛省によると、超音速グライディング・プロジェクタイル（HVGP）で、2026年に初期型のミサイルを配備し、2028年以降に強化型のミサイルを配備する計画だという。 計画されているミサイルは音速の5倍の速さで飛行することができ、超音速兵器となる。 このようなミサイルが実用化されれば、日本は中国、ロシア、米国に次いで世界で4番目の超音速滑空技術を持つ国となる。 この技術により、ミサイルは防空システムの弱点である大気圏上層部を高速で滑空し、複雑な軌道をたどることができるため、既存の対ミサイルシールドでは迎撃が困難になる。
Japan’s first missile would focus on land targets, while the upgraded version would feature claw-shaped payloads, enhanced speeds and firing ranges to attack large surface ships, the ministry said.
But its range would be limited to about 500km (310 miles) or less to keep within Japan’s “exclusively defence-oriented policy”. The ministry has also said the HVGP would carry warheads that could penetrate aircraft carrier decks. It said the missile was being developed for defence of its “remote islands” in the southwest, referring to the Okinawa Islands and surrounding islets including the disputed Senkaku archipelago – known as the Diaoyu Islands in China.
The uninhabited chain of islands in the East China Sea – about 420km (260 miles) from the main island of Okinawa – is claimed by Japan, China and Taiwan.
The defence ministry’s Acquisition, Technology and Logistics Agency is developing a scramjet engine to power the hypersonic missile with Tokyo-based Mitsubishi Heavy Industries.
Beijing-based military analyst Zhou Chenming said if Japan successfully developed the weapon, it could be a threat to Chinese navy activities in the area and it may have an impact on strategic balance in the region down the track. But he noted there had been delays in Japan’s previous weapons programmes. “There are many uncertainties … from Japan’s internal politics to its diplomatic policy changes, as well as military technologies,” he said. “So we will need to keep an eye on how this programme proceeds over the next few years.” China and Russia are for now the only countries with hypersonic glide missiles in service. Russia’s nuclear-capable Avangard hypersonic glide vehicle went into operation in December. And China became the first country in the world to announce the deployment of a hypersonic weapon when its DF-17 missile featured in the National Day military parade on October 1. In March, the US tested a common-hypersonic glide body, or C-HGB weapon, which will be nuclear-capable and could be based on land, air or sea. It hopes to complete the first missile in 2022.
