TOKYO -- Japan's Defense Ministry is considering upgrading its "hyper velocity gliding projectiles" (HVGP), a new type of missile it is seeking to deploy in fiscal 2026 for the defense of remote islands, to add an anti-ship capability to them, it has been learned.

The move is aimed at improving the defense of the Nansei Islands in southwestern Japan amid China's maritime activities in the region. HVGPs can glide at high velocity after payloads are detached from a rocket in the upper atmosphere where air resistance is low. The missiles are capable of following complex trajectories under the guidance of GPS and other systems, making it harder for an adversary to intercept them than conventional missiles.

The Defense Ministry eyes equipping HVGPs with a new type of payload that is capable of penetrating the deck of aircraft carriers. However, enhancing the firing range and other capabilities of Self-Defense Force (SDF) equipment could be called into question over its consistency with Japan's exclusively defense-oriented policy. The ministry therefore is planning to give due consideration, such as limiting the missile range to around 500 kilometers or less.

The development of HVGPs will come in two stages. In the first stage, an early equipment type will be developed for possible deployment by the Ground Self-Defense Force (GSDF) in fiscal 2026, targeting a potential enemy invading Japan's remote islands. In the second stage, an upgraded type will be developed for possible installation in fiscal 2028 or later, featuring claw-shaped payloads, enhanced speeds and firing ranges, and more complex trajectories.

Furthermore, the ministry is also mulling introducing advanced anti-ship and anti-surface missiles, which are currently under investigation by the Acquisition, Technology & Logistics Agency. If these technologies are incorporated into HVGPs, the projectiles can penetrate aircraft carrier decks, which are harder than its external walls, before being detonated inside the vessel to make it impossible for aircraft to take off or land, as well as destroy targets within a range of several hundred meters squared.

Behind the ministry's move lies China's intensifying maritime moves in waters near the Senkaku Islands in Okinawa Prefecture and other parts of Japan. In 2012, China commissioned its first aircraft carrier Liaoning, and the second such vessel, Shandong, was launched in 2019. Shandong is the first Chinese-made carrier. Beijing is said to be further seeking to add at least two more carrier vessels.

Chinese government vessels have been frequently spotted navigating in contiguous zones near the Senkaku Islands and intruding into Japanese territorial waters. While the main island of Okinawa and the Senkakus are about 420 kilometers apart, the GSDF's current missile range is set at just over a hundred kilometers. The introduction of longer-range gliding missiles to protect the Nansei Islands would make it possible for Japan to respond to China's activities without deploying the Maritime Self-Defense Force's vessels and aircraft.

The Defense Ministry allocated a total of 18.5 billion yen in the fiscal 2018 and 2019 budgets for research on HVGPs for the defense of remote islands, and plans to add another 25 billion yen in the fiscal 2020 budget. However, some legislators in the Diet have pointed out that acquisition of the new capabilities could "make it possible for the SDF to directly attack other countries' territories" and "deviate from Japan's exclusively defense-oriented policy." The development of the new technologies is also feared to threaten Japan's neighbors.

The government has defended the HVGP development, stating, "They are intended for homeland defense and are not considered attacking weapons."

(Japanese original by Yusuke Tanabe, Political News Department)