
When back in April North Korea launched what the international community claimed was a ballistic missile, the country that had the most to fear from the launch — Japan — failed to track it, raising anxiety in Tokyo that its defenses against a missile attack by Pyongyang were insufficient.

Ironically, the reason why Japan’s ground radars and Aegis destroyers, backed by U.S. early-warning surveillance satellites, were unable to track the launch is because the launch was a failure: the object, which Pyongyang all along maintained was an orbiter, never reached high enough an altitude to allow for its detection.

What came as an embarrassing failure for the North Korean regime served as a reminder to Tokyo that more was needed to ensure it had the ability to detect low-altitude objects as well as missile launches in their early phase. To address this shortcoming, the Japanese Defense Ministry has reportedly embarked on a multibillion-Yen program to develop unmanned aerial vehicles equipped with ultrasensitive infrared sensors to track ballistic (and possibly cruise) missiles as well as other low-altitude objects.

According to anonymous sources in the Japanese government, a prototype of the UAV, which would be able to operate at an altitude of about 13,500 meters, will be unveiled by the next fiscal year and enter service in 2020. By detecting launches earlier than ground-based radar are capable of, the new UAV would give Japan the ability to intercept ballistic missiles at an earlier stage, or at a minimum add to the series of points in the “kill chain” at which a ballistic missile can be shot down.

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Whether the Japanese drone will have enough endurance and be equipped with air-to-air missiles, such as, say, a recast AIM-120 Amraam with a second-stage liquid propulsion system, to act as an air-launched missile interceptor remains to be seen, though that would be the next logical step to having networked conventional aircraft, flying in or near North Korean airspace, do the job.

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There are several advantages to targeting an object during its boost, from the fact that the missile does not maneuver and presents a very high infrared signature. As it ascends, the missile is also slower than during the re-entry phase, which theoretically makes kinetic interception easier to achieve. Furthermore, an airborne surveillance aircraft close enough to the launch site would obviate the time and high-energy requirements of mid-course interceptor rockets used on current ground- or sea-based interceptors, thus allowing for cheaper and faster interception.

Lastly, but by no means insignificant, destroying a ballistic missile during that phase means that its destruction will occur on enemy territory rather than over one’s skies.

While destroying a ballistic missile during its launch phase makes good sense, doing so is easier said than done given its location in enemy territory, a feat that is made all the more formidable if that enemy’s airspace is covered by strong defense systems. The cost of boost-phase intercept using traditional manned aircraft — such as that envisioned in Raytheon Corp’s Network Centric Airborne Defense Element (NCADE) — is dauntingly high, from the number of sorties required to the risks of losing pilots and aircraft. However, low-signature drones could allow their user to penetrate enemy territory undetected and to linger longer near a launch site than conventional aircraft, thus increasing the chances of intercepting a ballistic missile using an NCADE or its equivalent. (Provided the drone had enough endurance, a future role in countering Chinese missile launches is also not impossible.)


Given the potential and relatively low cost of this endeavor, other countries that live under the constant shadow of a ballistic missile attack, such as Taiwan and South Korea, will look on with interest and could even decide to follow suit, technological capacity allowing. Japan’s efforts aren’t particularly new, as Raytheon’s program makes it clear. But they highlight the new possibilities unmanned platforms are creating in modern warfare.