K9MH Mobile Howitzer.

The K9MH, or K9 Mobile Howitzer, is a wheeled 155 mm self-propelled howitzer developed by the South Korean company Hanwha Aerospace, with its subsidiary Hanwha Defense USA responsible for its participation in U.S. programs. Formal development began in December 2024 under a 30-month program scheduled for completion in June 2027. Rather than converting an existing tracked K9 Thunder directly into a wheeled vehicle, Hanwha separated the artillery functions developed for the K9 family from the tracked hull, retaining the Hyundai WIA CN98 155 mm/52-caliber cannon, ammunition-handling technology, fire control architecture, and the K9A2's automation while redesigning the vehicle structure, crew compartment, ammunition arrangement, recoil-management system and automotive architecture around a heavy wheeled carrier. The resulting K9MH is therefore a separate wheeled branch of the K9 family rather than a K9A2 with its tracks replaced by wheels. Hanwha's initial architecture combines an automated rear artillery module (similar in principle to the AGM from KNDS), an armored forward crew cab, a heavy 8×8 chassis and four stabilizers, together with a wheeled ammunition-resupply concept derived from the tracked K10 Ammunition Resupply Vehicle (K10 ARV).

This design substantially changes how the gun crew operates compared with earlier K9 configurations. The K9MH carries three crew members instead of five, reducing the onboard gun crew by 40%, and all three personnel are seated in the armored cab at the front of the vehicle rather than being divided between the hull and turret. The rear artillery module is fully uncrewed, with projectile selection, projectile transfer, propellant selection, charge handling, loading, and gun laying performed automatically. Projectiles and modular propellant charges use separate automated handling paths because NATO 155 mm ammunition is not handled as a complete one-piece cartridge. This architecture allows the crew to conduct a normal fire mission without entering the turret or manually handling projectiles around the breech. At formation level, six K9MHs would require 18 onboard gun-vehicle personnel, compared with 30 for six tracked K9 Thunders, although command, ammunition, maintenance, communications, recovery and security personnel remain additional requirements and are not eliminated by gun automation.

The first complete K9MH howitzer uses a third-generation Tatra Force 8×8 chassis, also used by the Tatra 815-7 family, with the armored crew cab forward and the artillery module positioned over the rear axles. The prototype is estimated to measure close to 12 m in length, 3.4 m in width, and 2.73 m in height, with a gross mass close to 40 tonnes. Four stabilizers deploy around the rear before firing and transfer the recoil impulse of the 155 mm gun into the ground rather than requiring the suspension, tires and truck frame to absorb the complete firing load. The vehicle is consequently lighter than the tracked K9A2 Thunder weighing 48,500 kg, but remains a heavy military vehicle: its 3.4 m width exceeds the normal 2.55 m European road-vehicle width by 0.85 m, while its mass affects bridge classification, rail transport, recovery and strategic mobility. Still, Hanwha has designed the artillery gun module to allow its integration on other sufficiently capable trucks, including those from Mack Defense, but chassis substitution requires adequate axle ratings, braking, frame rigidity, hydraulic capacity, electrical generation, and structural interfaces. Discussions with Polish industry at Eurosatory 2026 showed these limits, as an existing Jelcz 8×8 could not accept the complete K9MH installation without developing a heavier vehicle.

The K9MH concept emerged publicly between 2025 and 2026. Hanwha Aerospace USA announced on October 9, 2025, that production of a wheeled K9A2-derived Mobile Howitzer had begun and linked the project to U.S. Army testing and the Common Gun System approach. A model of the concept was also displayed at AUSA 2025 in Washington, D.C. The first images of the complete vehicle appeared in spring 2026, including disclosure of the prototype in late March, and Hanwha Defense USA formally positioned the K9MH for the U.S. Army Mobile Tactical Cannon (MTC) competition on March 31, 2026. A subsequent firing demonstration near Changwon, South Korea, provided a quantitative demonstration of its automated artillery system, with the vehicle firing nine rounds in 59 seconds, equivalent to a maximum firing rate of 8 to 9 rounds/min, and individual firing intervals close to 7.5 seconds. After arriving at a firing position, the K9MH can fire its first round within about 20 seconds, with deployment of the stabilizers and preparation of the gun taking less than 30 seconds. After completing the fire mission, the howitzer can leave the position in less than 30 seconds.

The K9MH retains the Hyundai WIA CN98 155 mm/52-caliber cannon used by the K9 Thunder. The 52-caliber designation corresponds to a nominal barrel-length relationship of 8.06 m, or 52 times the 155 mm bore diameter, and the weapon complies with the NATO Joint Ballistics Memorandum of Understanding (JBMOU) for 155 mm artillery interfaces. The K9MH carries 40 projectiles and 192 modular propellant charges, compared with 48 projectiles and 240 charges in the tracked K9 configuration. Conventional ammunition provides a firing range of around 40 km, extended-range and rocket-assisted projectiles can exceed 60 km, with the highest figures approaching 70 km depending on projectile, propellant, and ballistic configuration. A 155 mm/58-caliber weapon, corresponding to a nominal barrel-length relationship of 8.99 m, has also been considered, but it is currently not part of the baseline K9MH armament. At eight rounds/min, the onboard 40-projectile magazine mathematically represents five minutes of firing at the maximum rate, increasing the importance of the associated wheeled K10-derived ammunition-resupply vehicle concept.

The K9MH entered formal U.S. Army prototyping on August 18, 2026, when the service selected Hanwha Defense USA for the Mobile Tactical Cannon (MTC) prototype effort. The agreement has an initial value of $100,302,961 and a maximum cumulative face value of $262,903,274, covering six initial prototype systems with an option for 12 additional vehicles, potentially producing an experimental fleet of 18 K9MHs during an estimated four-year evaluation period. Dividing the maximum agreement ceiling by all 18 potential systems gives $14.61 million per vehicle, but this is not a K9MH production unit price because the ceiling includes prototype development, integration, experimentation, and associated program activities. More importantly, the August 2026 decision does not make the K9MH the winner of the MTC acquisition program: the Army selected it for prototyping and Soldier experimentation, during which performance, reliability, supportability, ammunition integration, and operation will be assessed before any production or fielding decision. The MTC is intended to provide a mobile 155 mm capability replacing M777 towed howitzers in selected formations if the program proceeds to fielding, with the potential requirement reaching as high as 498 guns.

The United States is the first confirmed K9MH prototype customer, but as of August 19, 2026, the system remains in pre-production development and has not entered operational service with either the U.S. Army or another armed force. Hanwha is establishing an integration and test facility at Opelika, Alabama, initially supported by more than $2 million in investment, providing the first element of a U.S.-based industrial structure for the MTC prototype effort. Outside the United States, Spain is identified as a potential customer, in connection with a requirement for 86 wheeled 155 mm howitzers and supporting vehicles, while Poland has been examined as another possible market but would require a heavier carrier than the existing Jelcz 8×8. No country other than the United States has placed a confirmed K9MH prototype order to date, and even the U.S. agreement remains an experimentation contract rather than a commitment to serial production. The system's immediate development path therefore runs through both the completion of Hanwha's original engineering program in June 2027 and parallel U.S. Army prototype evaluation, after which the U.S. Army will determine whether K9MH, another solution, or no MTC production system proceeds to operational fielding.

No formally designated production variants of the K9MH are identified as of August 19, 2026. The program remains in development, and the configurations concern alternative guns and chassis rather than separately named K9MH variants.

• K9MH 155 mm/52-caliber: This is the demonstrated configuration and the basis of the U.S. Mobile Tactical Cannon prototype. It carries 40 projectiles, uses the CN98 155 mm/52-caliber gun, K9A2-derived automated ammunition handling, an uncrewed turret, and a Tatra heavy 8×8 chassis.
• Alternative chassis: Although the K9MH prototype uses a Tatra 8×8 chassis, a scale model has also been displayed on a Mack Defense chassis, reflecting Hanwha's decision to design the artillery module with mechanical and electrical interfaces that allow it to be adapted to different heavy 8×8 trucks with sufficient payload capacity.