The Hwasong-15 (U.S. designation: KN-22) is a North Korean intercontinental ballistic missile. It employs two liquid-fuelled stages with an estimated range of up to 13,000 km.

Hwasong-15 Development

North Korea began developing the Hwasong-15 sometime before 2017. The U.S. intelligence community was apparently aware of the Hwasong-15’s development before its maiden launch, and the missile’s design suggests a shared heritage with the Hwasong-14 and Hwasong-12 missile designs.¹ North Korea tested the Hwasong-15’s “high-thrust” engines in March and June of 2017.²

North Korea flight tested the Hwasong-15 for the first time on November 28, 2017 from a site 30 km north of Pyongyang. The missile flew for 53 minutes, reaching a maximum altitude of 4,500 km to a range of 960 km before landing in the Sea of Japan.³ Fired on a flatter trajectory, the missile could travel up to 10,000 km, enough to hold the continental United States at risk.⁴ North Korea likely tested the missile a second time on March 24, 2022, in an apparent attempt to conceal a failed Hwasong-17 flight test ten days prior.[Brad Lendon and Gawon Bae, “North Korea not telling the whole truth about latest ICBM test, South Korean official says.”

North Korea’s official statement on the Hwasong-15 flight test claimed that the missile can carry a “super-large heavy warhead which is capable of striking the whole mainland of the U.S.” It also noted that the missile had “greater advantages in its tactical and technological specifications and technical characteristics than [the] Hwasong-14,” referring to the ICBM North Korea tested twice in July 2017.

Specifications

The Hwasong-15 measures an estimated 21-22.5 meters in length and 2 – 2.4 meters in diameter. This is notably larger than its immediate predecessor, the Hwasong-14.⁵ The missile’s more spacious payload fairing may allow the future deployment of large or multiple nuclear warheads and penetration aids to complicate missile defense. ⁶

The missile appears to employ two of the Hwasong-14’s “Korean-style high-thrust” engines in its first stage.⁷ An indigenously-produced variant of the Soviet-designed RD-250 engine, the motors use higher-energy propellants to produce up to 48 tons of thrust apiece.⁸

The absence of secondary steering thrusters (Vernier thrusters) on the Hwasong-15 suggests that the rocket’s main nozzles can pivot to control the rocket’s flight path.⁹ Such a system, known as a gimbaled thruster, imposes fewer range penalties than using fins or Vernier thrusters for control. The Hwasong-15’s second stage configuration remains unknown. It may employ the same RD-250-type engine as the first stage, or a different type entirely.

The Hwasong-15 is launched from a firing platform that separates from its transporter-erector (T/E) truck. The truck that carries the missile, believed to be a Chinese WS51200 logging truck previously used for the Hwasong-14, has been modified with an additional ninth axle to accommodate the missile’s larger size.¹⁰ The erector uses a different heave arm from the Hwasong-14 to raise the missile into launch position. While the Hwasong-14 uses a single central heave arm, the Hwasong-15 uses two heave arms on either side of the vehicle.¹¹