South Korea’s Hyunmoo-5 spotlighted after first combat use of GBU-57

Interest is mounting in South Korea’s domestically developed bunker-buster missile, the Hyunmoo-5, following the United States’ strike on three Iranian uranium enrichment facilities using the GBU-57, widely regarded as the world’s most powerful bunker-penetrating weapon. Unlike the air-dropped, air-to-surface GBU-57, the Hyunmoo-5 is a ground-launched ballistic missile with a maximum range of approximately 300 kilometers.

On June 21 (local time), the U.S. military deployed six B-2 stealth bombers to drop 14 GBU-57 Massive Ordnance Penetrators (MOPs) on Iran’s Fordow nuclear facility. It marked the first known combat use of the GBU-57 since it was officially integrated into the U.S. arsenal in 2023.

Measuring 6.1 meters in length and weighing 13.6 metric tons, the GBU-57 is capable of punching through up to 60 meters of reinforced concrete. Dropped from a B-2 bomber, it descends solely by gravity, without a propulsion system.

The Fordow site is believed to house nuclear infrastructure located 80 to 90 meters underground, shielded by reinforced concrete. Israel, having determined that the facility was difficult to neutralize, had reportedly asked Washington to provide access to the GBU-57.

South Korea’s Hyunmoo-5 missile features a warhead weighing up to 8 tons—more than triple the GBU-57’s 2.4-ton payload. The missile was publicly unveiled for the first time in October last year during a ceremony marking South Korea’s Armed Forces Day. At the time, Kim Yo-jong, the powerful sister of North Korean leader Kim Jong-un, dismissed it as a “bloated and useless weapon.” However, defense analysts say the Hyunmoo-5 possesses enough strike capability to raise alarm in Pyongyang.

The Hyunmoo-5 ascends to an altitude of up to 1,000 kilometers before plunging toward its target at speeds exceeding Mach 10, powered by a rocket booster. This extreme velocity allows it to penetrate fortified underground facilities while making interception by current missile defense systems highly unlikely. In addition to the force of its high-mass warhead, the missile generates intense kinetic energy during descent, potentially causing artificial seismic shocks capable of obliterating subterranean bunkers. Some experts assess that its destructive potential exceeds that of the GBU-57.

The Hyunmoo-5 is reportedly capable of destroying bunkers buried as deep as 100 meters. According to military sources, the South Korean armed forces have drawn up contingency plans to deploy 20 to 30 Hyunmoo-5 missiles to level Pyongyang in the event of a North Korean invasion.