Hwasong-16 LRBM

The suspected former HS-16 is officially the HS-17.

The HS-16 was shown for the first time at the exhibition in October 2021. The first launch was on 04 January 2022. This short missile, derived from the HS-12, has a simple RV with stabilizing fins. The missile achieves a higher velocity in climb thanks to the approximately one-third lower amount of fuel, but has a shorter burning time and also a shorter range.

North Korea conducted an apparent missile test, South Korea and Japan reported, just days after an end-of-year speech in which leader Kim Jong Un focused on domestic economic woes rather than military advancements. North Korea fired at least one projectile toward the sea off its east coast early Wednesday, South Korea's Joint Chiefs of Staff said in a statement. Japan's coast guard said the launch may have involved a ballistic missile. No further details were available, including how many missiles were launched, how far they went or where they landed.

Japanese Defense Chief Nobuo Kishi has since indicated that the projectile flew over a standard trajectory for roughly 500 kilometers. He further stated there were no reports of damages caused by the launch. It was the first missile test by the Democratic People's Republic of Korea (DPRK) since October, when it fired off a submarine-launched ballistic missile (SLBM). Despite the latest missile test, Moon said he would not give up hope for dialog with North Korea, according to his office. "We should not give up the hope for dialogue in order to fundamentally overcome this situation," he said. "If both Koreas work together and build trust, peace would be achieved one day."

According to Rodong Sinmun, the official paper of the ruling Workers Party of Korea, the test accelerated the task of "modernizing the national strategic force." The paper says the test verified the ability of the fuel ampoule system to operate "under winter weather conditions" and demonstrated an increased ability to stabilize and control the hypersonic glide vehicle, "which combined a multi-stage gliding jump flight and a strong lateral movement." The glide vehicle is boosted by a rocket engine during the initial stage of a hypersonic weapon's launch before detaching and gliding toward its target, adopting an unpredictable flight path to avoid interception.

"In the test launch, the [Academy of Defense Science] reconfirmed the flight control and stability of the missile in the active-flight stage and assessed the performance of the new lateral movement technique applied to the detached hypersonic gliding warhead," the Sinmun said. "Having detached after its launch, the missile made a 120 km lateral movement in the flight distance of the hypersonic gliding warhead from the initial launch azimuth to the target azimuth and precisely hit the target 700 km away," it added.

The January 2022 launch was the DPRK's second test of a hypersonic weapon. The first, an unrelated glide system, was held in September, timed to coincide with the socialist nation's envoy to the United Nations taking the podium at the General Assembly in New York to speak about the DPRK's right to self-defense but willingness to talk peace, which has eluded the peninsula for 72 years. That other weapon is named Hwasong-8.

In the continuing race between the designers of attack missiles and the designers of countermeasures, missiles are improved by becoming more sophisticated. Among such improvements is the introduction of missile maneuvers during exo-atmospheric and endo-atmospheric flight. Such maneuvers may defeat ballistic missile engagement systems which are predicated on ballistic motion of the target. One option for countering U.S. missile defenses would be the development of a maneuvering reentry vehicle (MARV). The maneuvering capability could be used to complicate hit-to-kill or conventional warhead ballistic missile defense systems.

One type of atmospheric re-entry vehicle (RV) is a ballistic RV which, after an initial launch and boost phase, follows a substantially purely ballistic path after separation from a launch vehicle. That is, the position of the RV target can be predetermined if the velocity of the RV and if the boost phase trajectory is known. One disadvantage associated with a purely ballistic RV is that, inasmuch as the target position can be predetermined after separation, interception of the RV can be readily accomplished.

To improve survivability, it is thus desirable to provide an improved type of RV which is an evader maneuvering RV (EMRV) capable of executing in-flight evasive maneuvering operations after re-entry. Inasmuch as the trajectory of the EMRV after re-entry would not be required to be purely ballistic, the position of the EMRV's target would remain uncertain until the completion of the maneuverers. Thus, interception of the EMRV would be made difficult to accomplish.

Such an EMRV would include a suitable maneuvering capability and also a three-axes navigation system for guidance. Preferably, the navigation system would employ a strap-down inertial navigator having ring laser gyroscopes (RLGs) which are inherently more rugged and capable of executing high-G maneuvers than are conventional mechanical gyroscopes. One purpose of the navigation system is to maintain EMRV position information during evasive maneuvering such that the EMRV can be guided to a target at the completion of maneuvers. The EMRV would also typically include an altitude measuring system, such as a radar altimeter, in order to fuse the EMRV's ordinance at a predetermined altitude.

Following the boost phase, and during a coast phase, an EMRV is spin stabilized. As can be appreciated, even with the greatly improved scale factor stability which is obtainable with modern RLGs, a high-G EMRV maneuvering phase will result in a significant EMRV position error at the completion of maneuvering due to the loss of altitude reference during the spin stabilized coast phase. If uncorrected, the computed position of the target relative to the EMRV will also be in error. Known techniques of compensating for the altitude reference error prior to high-G maneuver, or alternatively for the position error following the high-G maneuver are generally inappropriate in an EMRV due to at least the increased weight and complexity associated with such correction systems.

Generally, the hypersonic reentry vehicle enters the atmosphere of the Earth at an altitude of about 100~120 km. The full flight trajectory ranges from the high orbital reentry interface to the terminal area at 20~30 km in altitude. The reference trajectory is typically generated offline and preloaded on the hypersonic glide vehicle before launching. It is often required to correct the reentry trajectory for tracking errors during the reentry flight and even to replan a reference trajectory onboard for reaching a new target or aborting. It is a challenging task to optimize a reference trajectory in real-time for hypersonic glide vehicle, since the dynamics model is highly nonlinear along with limited control authority in the reentry flight.