German Navy tests new naval IRIS-T SLM air defense on F125 frigate during Andøya 2025.

Diehl Defence has successfully test-fired a navalized IRIS-T SLM missile from the F125 frigate Baden-Württemberg during the German Navy’s Maritime Firing Exercise 2025. The milestone marks the first at-sea launch of the system and signals Germany’s move to extend its warship air-defense reach beyond close-range intercepts.

Diehl Defence announced on October 15, 2025, that the company has fired a navalized demonstrator of its IRIS-T SLM air defense system during the German Navy’s Maritime Firing Exercise 2025, codenamed Andøya. The launcher and fire-control “AAW module” was installed on the C-deck of F125 frigate Baden-Württemberg after a rapid integration sprint that went from concept to live firing in under ten months. Diehl reports the system met all test aims and achieved a high hit rate, marking the first at-sea firing of an IRIS-T family missile from a navalized SLM configuration. The trial follows combat use of the ground system in Ukraine and clears a path toward series introduction for the fleet.
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Naval IRIS-T SLM is a containerized deck launcher giving 360° medium-range defence (~40 km) with IIR seeker, datalink-guidance and high-agility intercepts against missiles, aircraft and drones (Picture source: German MoD and Diehl Defence)

The F125 shipboard setup used a deck-mounted, self-contained module for trials, a pragmatic bridge solution for a class that lacks a vertical launch system. The demonstration is intended to close a well-understood self-defense gap on the F125s, whose organic missile protection had been limited primarily to RAM. The outlet also reiterates IRIS-T SLM’s effective intercept envelope of about 40 kilometers and 20 kilometers in altitude, offering a step change over close-in defenses.

At the missile level, IRIS-T SL builds on the well-known IRIS-T air-to-air round with a larger 152 mm motor, GPS-aided inertial navigation, and a datalink for mid-course updates before handing off to an imaging infrared seeker in the terminal phase. A radar proximity fuze and high off-boresight agility, aided by thrust-vector control, support hard-kill probability against maneuvering targets, while a jettisonable nose cone reduces drag in the boost phase. These design choices are what give the SLM its 360-degree engagement geometry and the reach cited above.

Translating the land-proven architecture to sea hinges on sensors and battle management. On land, IRIS-T SLM batteries are commonly paired with Hensoldt’s TRML-4D for target acquisition. Aboard Baden-Württemberg, cueing would instead flow from the ship’s fixed-panel TRS-4D AESA, already integrated with the combat management system, providing rapid 3D tracks and volume search out to hundreds of kilometers. The demonstrator’s containerized approach lets the missile battery ride on the ship’s existing sensor backbone without structural changes to accommodate a VLS, while Germany continues a separate, BAAINBw-backed study on deeper IRIS-T SLM integration for the F125s.

The navalized SLM would extend an F125’s defended footprint from the current RAM bubble of roughly 9 kilometers to a layered envelope capable of killing sea-skimmers, complex drones, and strike aircraft before they reach terminal attack. The missile is not a ballistic missile defense solution, but its reach and IIR terminal discrimination materially raise ship survivability against modern anti-ship raids. For commanders, the value is the time and geometry it buys. A 40-kilometer outer ring gives more engagement windows, supports re-attacks if needed, and eases deconfliction with guns and soft-kill at short range.

Germany’s recent Red Sea experience under the EU’s Aspides escort mission put a spotlight on which platforms could stand in contested littorals for months at a time. Sachsen-class AAW frigates carried that burden in 2024, while an F125 on global deployment avoided the threat region, a reflection of the class’s limited missile reach. By pushing IRIS-T SLM to sea, Berlin is moving to harden a high-availability frigate built for stabilization and presence so it can better weather the drone and cruise-missile saturation tactics now common from the Black Sea to the Bab el-Mandeb.

Diehl’s statement frames Andøya as a milestone toward series naval introduction, and prior documentation shows Berlin has already funded feasibility work for F125 integration. If the Navy and BAAINBw move quickly, a containerized SLM layer could be fielded as an interim solution while options for permanent launch arrangements mature, including potential VLS paths studied for future classes. For allies weighing ESSM or CAMM families, a naval IRIS-T SLM offers an alternate, IIR-centric philosophy that has already proved its worth on land.