North Korea’s Hypersonic Hype: Success or Bluff?

This marks the scene of a hypersonic boost-glide missile launch, as documented by North Korea’s Central News Agency.

On the 15th, North Korea’s Central News Agency reported, “On the afternoon of January 14, the Missile General Bureau conducted a test launch of a medium-range solid-fuel ballistic missile equipped with a hypersonic maneuverable warhead.”

The news agency elaborated that the objective of the test launch was to verify the flight and maneuvering capabilities of the medium-range hypersonic maneuverable warhead and to evaluate the reliability of the newly developed multi-stage high-thrust solid fuel engines. It was reported that the test launch was successful.

What does this mean?

Translating North Korea’s claim indicates that instead of liquid rockets, they successfully tested a boost-glide weapon capable of hypersonic low-altitude flight using a solid rocket with a faster response rate.

On September 28, 2021, North Korea launched a Mars-8 ballistic missile using a boost-glide method. This method employed the first stage of the Mars 12, which utilizes a liquid rocket. After separating from the boost rocket, the boost-glide warhead covered a distance of fewer than 124 miles while maintaining an altitude of about 18.6 miles and a speed of Mach 2.5 to 3.

However, considering that the definition of hypersonic speed starts at Mach 5 and above, North Korea’s demonstrated speed of Mach 2.5 to 3 and maneuvering distance of less than 124 miles do not qualify as hypersonic capabilities.

This is the appearance of the Mars-8 boost-glide weapon released by North Korea. What was launched this time seems to be an improved version of this.

Did they succeed in improving it?

This time, the model launched by North Korea differed from the usual liquid rockets that require extensive launch preparations; instead, it utilized a solid rocket.

According to observations by the US-Korea alliance, North Korea’s boost-glide weapon, which detached from the solid rocket, reportedly covered a distance of approximately 621 miles. In contrast, Japan’s observation placed it at around 310 miles, with the missile maintaining a cruise altitude of roughly 31 miles.

The variance in reports between the US-Korea alliance and Japan can be attributed to the tracking capabilities. South Korea was able to consistently monitor North Korea’s missile launch by employing an early warning radar for ballistic missiles located at the same latitude.

In contrast, Japan relied on an early warning radar for ballistic missiles situated further from the missile’s flight path on the Japanese mainland. Due to the low cruising altitude of the North Korean missile, it was challenging to track accurately due to the horizon limit.

As a result, the announcement from the US-Korea alliance is considered more precise, indicating that, unlike previous instances, North Korea’s boost-glide weapon achieved a remarkable range of up to 621 miles.

This is South Korea’s early warning radar for ballistic missiles, boasting an impressive detection range of 497 miles, with a current deployment of four such systems.

Interestingly, despite the comprehensive understanding held by the US-Korea alliance and Japan regarding the missile’s flight, they have refrained from disclosing its speed.

The speed information is likely to be revealed in due course. However, the delayed disclosure compared to previous incidents strongly suggests that North Korea has successfully tested a hypersonic boost-glide weapon. It is important to note that this remains an estimate at this point.

The cautious approach by the Korean Ministry of National Defense in making an official announcement stems from the potential implications. If North Korea has indeed developed a hypersonic boost glide weapon, intercepting it effectively with South Korea’s KAMD (Korean Air and Missile Defense) system could be a considerable challenge. In essence, the stakes are high, prompting a careful and thorough analysis of the situation.

What is a boost-glide weapon?

A boost glide weapon, much like a conventional ballistic missile during its ascent phase, utilizes a solid rocket booster to ascend, gaining altitude and speed. However, the key distinction lies in its descent phase. While a conventional ballistic missile follows a parabolic trajectory, descending directly after reaching the ballistic vertex, a boost-glide weapons system maintains control over its posture. It deliberately maintains a slight angle of attack against the Earth’s atmosphere using the rear end of the reentry vehicle. This prevents it from falling with the warhead oriented downward after reaching its peak altitude.

This shows the Reentry Vehicle (RV) and the Hypersonic Boost Glider (HGV) flight patterns. The ballistic missile, marked in blue, provides relatively clear flight information if you track its speed and direction. However, the information that can be obtained by tracking the trajectory of the Hypersonic Boost Glider (HGV), marked in red, is only the current location information and speed.

Soaring in the atmosphere?

Crucially, instead of reentering the atmosphere traditionally, a boost-glide weapon harnesses the shockwave generated during hypersonic flight. It effectively “rides” or “skims” along the upper atmosphere, bouncing off it like a surfboard or water skimmer, and subsequently descends at high velocity toward its intended target. This process is repeated, akin to a surfboard gliding across waves, propelling the weapon toward its destination.

Notably, the reentry vehicle lacks a distinct propulsion system during this phase. It relies solely on the energy derived from its initial launch using the rocket booster and the inherent aerodynamic design for its flight.

As a result, it stands apart as a distinct category of weaponry known as a hypersonic boost glider weapon. This sets it apart from ballistic missiles, which follow a ballistic trajectory, and supersonic cruise missiles, which utilize continuous propulsion throughout their flight.

This is the model of the Hypersonic Boost Glide interceptor missile, IRIS-T HYDEF, proposed by Diehl. The U.S. has not yet secured a weapon to intercept a Hypersonic Boost Glide in flight.

The Danger of Boost-Glide

The rationale behind the development of boost-glide weapons systems by not only major players like the U.S., China, and Russia but also by rogue states like Iran and North Korea lies in the inherent difficulty of countering their flight characteristics compared to conventional ballistic missiles.

Conventional ballistic missiles follow a parabolic trajectory, covering the shortest distance between the launch point and the intended target post-launch. This trajectory passes through the most direct route connecting the launch and target points. Consequently, it becomes possible to estimate the missile’s speed, altitude, and azimuth as it descends after crossing its peak altitude, allowing for predicting its flight path and impact point.

Modern ballistic missile interception systems take advantage of these predictable flight traits of ballistic missiles. They launch interceptor missiles toward the anticipated location of the ballistic missile based on these estimations.

In contrast, boost-glide weapons systems employ a flight pattern that complicates interception efforts, making them considerably more challenging to counter effectively.

This is Iran’s recently unveiled Fatah Hypersonic Boost Glide weapon, and it is worth noting that Iran and North Korea are collaborating on developing such hypersonic boost glide technology.

In contrast to ballistic missiles, the boost-glide weapons system executes a hypersonic gliding flight along the upper atmosphere, akin to sliding or gliding after an initial rapid descent following the launch phase, resembling the ascent phase of a ballistic missile. Consequently, compared to a ballistic missile utilizing a similar-class rocket booster, the boost-glide system can extend its range by approximately 50% to 100%, making it nearly impossible to predict its precise impact point.

Moreover, the boost-glider weapons system can perform relatively subtle turns or direction changes through the reentry glider’s aerodynamic control. Exploiting these capabilities thwarts any accurate fall path predictions. It dramatically enhances interception difficulty by evading predefined interception zones, especially when the location of the enemy’s ground-to-air missile interception area is identified.

This is a conceptual diagram of the L-SAM anti-ballistic missile being launched. The L-SAM anti-ballistic missile is composed of three stages, and based on this rocket technology, a Korean-style boost glide interceptor is planned to be developed.

How can South Korea prepare?

Fortunately, countermeasures are being actively developed in South Korea.

On April 25, 2023, the Defense Project Promotion Committee convened its 153rd meeting. During the session, they reviewed and approved a project to develop and deploy the L-SAM Block II, an upgraded version of the L-SAM currently in development, to achieve capabilities comparable to the THAAD system. The project entails a substantial investment totaling 2.710 trillion won, roughly equivalent to $2.3 billion, with the goal of completion by 2035.

An intriguing aspect of this development is that, in addition to the previously planned 150km altitude interceptor, known as the THAAD, the L-SAM Block II project includes the development of a Hypersonic Boost Glide Missile interceptor designed to intercept hypersonic boost-glide missiles during their flight’s boost phase, referred to as the Glide Phase Interceptor.

The accompanying diagram, released by the Ministry of Defense, illustrates the L-SAM Block II concept. It reveals the addition of a new high-altitude interceptor missile and a boost-phase interceptor missile to the existing L-SAM battery.

It’s worth noting that the Glide Phase Interceptor shares several components with the high-altitude interceptor missile but differs in critical aspects. The development of the boost-phase interceptor missile will be built upon this foundation. There are also plans to create a ballistic missile interceptor for integration into the KF-21 Boramae fighter jet.

Importantly, intercepting boost-glide weapons is not an impossible challenge; it simply shortens the interception range of the Patriot PAC-3 or Cheongung Block II systems currently possessed by the Korean military. In Korea, there are intentions to deploy up to 768 missiles, making it well-equipped to address these threats effectively.

This is a test launch of the Cheongung Block II system, designed to intercept boost-glide weapons. However, it’s important to note that a substantial deployment of these interceptors is necessary due to their limited interception range.

Thankfully, our company has synchronized the release of an e-book with North Korea’s recent hypersonic boost-glide weapon launch. The e-book, titled Air-to-air Armament for KF21 and New Technologies for Cheongung and L-SAM, delves into the concept of hypersonic boost-glide weapons, provides insights into the development of interception technologies worldwide, and crucially, offers an in-depth explanation of ongoing development projects. We highly recommend this resource for a comprehensive understanding of Korea’s hypersonic boost glide interception system.