A recent feature on Ukrainian military television presented the Iris-T medium-range air defense system from Diehl Defense took center stage. Of particular note was a picture of a command post container of a battery equipped with numerous kill marks – impressive proof of the ongoing success of the air defense system in the Ukraine war (-> current news from the Ukraine war).
As can be seen from the National Defense Report 2023 under point 7.2.3.3, Austria has expressed interest in the Iris-T SLM system. In addition, the European Defence Industry Reinforcement through Common Procurement (EDIRPA) is promoting the joint procurement of Iris-T SLM air defence systems with the JAMIE program. procurement of medium-range Iris-T SLM air defense systems by six member states, including Austria. – including Austria. In addition Austria is also part of the European Sky Shield Initiative (ESSI), which also focuses on IRIS-T.
Reason enough for us to take a closer look at the system.
The roots of the Iris-T system from Diehl Defense
The origins of Iris-T go back to the desire of several European air forces to develop a successor to the US Sidewinder short-range air-to-air missile. The knowledge gained with the Russian MiG-29 and the associated Vympel R-73 (NATO code: AA-11 Archer) after German reunification played a key role in this: With numerous NATO-air combat maneuvers, the highly agile R-73, which was controlled by the MiG-29 pilot using a helmet-mounted sight, proved to be a superior weapon in close-range air combat – a decisive impetus for the development of the Iris-T.
Today, the system is the primary short-range air-to-air missile for the Eurofighter, the Saab Gripen and other fighter aircraft types. It is used by the air forces of more than ten countries – including Austria.
The IRIS-T air-to-air missile
The name Iris-T stands for InfraRed Imaging System Tail/thrust vector-controlled – in other words, an infrared imaging system with thrust vector control. And the name says it all: at the front end of the rocket is a swivel-mounted seeker head with an infrared imaging sensor. This uses a mirror system to generate a high-resolution infrared image with 128 × 128 pixels 80 times per second. The target can be detected via various sources:
- a connected weapon system (e.g. radar),
- a helmet visor,
- a missile approach warning system,
- or data link.
After launch, the control system at the rear of the rocket takes over control. It consists of four aerodynamic control surfaces for attitude control. However, the exceptional maneuverability, especially during the launch phase, is achieved by four thrusters that deflect the exhaust jet of the solid-fuel engine in a targeted manner, thus enabling extreme changes of direction.
The powerful solid-fuel engine accelerates the Iris-T to over Mach 3, while at the same time it can maneuver at a turn rate of up to 60 degrees per second. Theoretically, this would enable it to perform a U-turn in flight with the area of two soccer pitches at full thrust.
The rocket can withstand loads of over 100 g without any problems. With a length of 2.9 meters and a weight of 88 kilograms, it has a theoretical range of up to 25 kilometers.
Flexible search head for 360-degree detection
The unique selling point of the Iris-T: it is capable of intercepting other air-to-air missiles in flight and thus serves as an additional self-defense system for the carrier aircraft.
The Iris-T’s seeker head does not need a target in its field of view for take-off, but can only detect it after launch. This means that targets can be engaged not only in front of the carrier aircraft, but also behind it. The missile’s operational area thus extends almost spherically around the carrier aircraft.
The imaging infrared sensor uses an internal library with typical infrared signatures of various air targets from different angles for target detection and identification. This enables the missile to distinguish between an interfering object and the actual target.
To ensure that the hit is as effective as possible, the library also contains information on where a target should be hit to cause maximum damage.
Warhead and ignition
The payload of the Iris-T consists of an 11.4 kilogram warhead with pre-fragmented fragments. This is detonated either by impact or via a radar proximity sensor and ensures a high destructive effect against the intended target.
As the infrared imaging technology of the Iris-T is gradually becoming outdated after 20 years, the BAAINBw (Bundeswehr Procurement Office Bundeswehr) signed a contract at the end of December 2024 contract with Diehl Defence for the further development of the Iris-T Block II.
The focus of the Block II variant is a comprehensive modernization of the electronics to make the rocket fit for the coming years. Important improvements concern:
- Reaction speed,
- Range,
- Quality of target acquisition,
- Resistance to interference,
- and the data link capabilities.
The Iris-T surface-to-air missile
The development of the Iris-T SLS system is largely based on an economic decision.
The Iris-T missiles carried on fighter planes are constantly exposed to stresses such as vibrations, extreme temperatures and pressure differences during their use. Over time, these influences add up to such an extent that the manufacturer’s warranty expires – even if the missiles are still fundamentally functional.
In contrast, unused rockets, rockets that are taken out of flight operations in good time, can remain operational for many years if stored carefully in containers. Over time, this results in a growing stock of unfit but technically intact missiles.
The solution: a second life as a surface-to-air missile – and that is exactly what Iris-T SLS is based on.
The Iris-T SLS system implements precisely this concept: it uses the air-to-air missile as the basis for a ground-based short-range air defense system.
- Sweden uses the BV410 Hägglunds as the carrier system and designates the system as RBS 98.
- In Ukraine, Iveco 4×4 trucks (see picture above) are used as launch vehicles.
During a ground launch, the missile achieves a range of up to 10 kilometers and can engage targets at altitudes of up to 8 kilometers.
The Iris-T SLM system
In the mid-2000s, the BAAINBw then called for the development of a ground-based air defense system to cover the airspace below long-range systems such as Patriot and the never-realized MEADS.
The Iris-T SLM uses the sensor package of the air-to-air missile, but combines it with a significantly larger solid-fuel motor, which also has thrust vector control.
The result: a 240-kilogram missile with an expanded diameter of 152 mm that reaches a speed of over 1,000 meters per second when launched from the ground.
During launch, the seeker head of the Iris-T SLM is protected by a streamlined cover. This is jettisoned as soon as the missile reaches a distance at which it can detect a target.
Up to this point, control is via:
- improved internal attitude control (INS),
- GPS navigation,
- and a 2-way data link to the radar of the air defense battery.
The Iris-T SLM has a range of up to 40 kilometers and can engage targets at altitudes of up to 20 kilometers.
Until launch, the missile remains in a sealed storage, transport and launch container, which reduces maintenance and ensures its operational readiness for years to come.
Wegen „Kill Switch“ und heiklen Abhängigkeiten: Abkehr vom F-35
The battery
Diehl Defence acts as general contractor and system integrator of the Iris-T SLM system and supplies the missiles.
The heart and brain of the battery is the C2 command post (TOC – Tactical Operations Center), housed in a container. The command post software, IBMS-FC (Integrated Battle Management Software – Fire Control), comes from Airbus and controls the entire mission coordination.
The battery sensor is the TRML-4D multifunction radar from Hensoldt. With a range of up to 250 kilometers, it can monitor an area of around 200,000 square kilometers and simultaneously track up to 1,500 targets.
The command post container, the radar and the three to eight launch vehicles, each carrying up to eight ready-to-launch missiles, are transported on all-terrain 8×8 HX trucks from Rheinmetall MAN Military Vehicles manufactured in Vienna.
The Iris-T SLM system enables 360-degree all-round defense against aircraft, helicopters, drones (-> To the current military drone topic) and other missiles. Thanks to the ability to bring the launch vehicles into combat position within a radius of up to 20 kilometers from the radar and C2 command post, one battery can cover an operational area of around 5,000 to 7,000 square kilometers.
The cost of a complete battery, including missiles, is around 200 million euros.
Iris-T SLM in the Ukraine
By February 2025, Ukraine had received a total of six Iris-T SLS/SLM air defense systems. The first system was put into service in October 2022 after a ten-week training phase.
According to Diehl Defence, Ukraine was able to record more than 100 successful launches in the first year alone – with an almost 100 percent hit rate.
There is no doubt that these figures are correct, as all operational data from the missiles fired is most likely transmitted directly to the manufacturer. This real combat data is essential for continuous improvements and optimization of the system.
Growing number of users and increased production
Ingo Gerhartz, head of the German Air Force, is also satisfied. In September 2024, Germany became the third country after Ukraine and Egypt to put the Iris-T SLM system into service in Todendorf with Air Defense Missile Group 61 (FlaRakGrp 61) (-> Iris-T SLM for the Bundeswehr). Other (planned) user states are Estonia, Latvia(-> report0), Slovenia (-> report) and Bulgaria (-> report).
The rapid increase in production at Diehl Defence is particularly remarkable – and by no means a matter of course. As this is a brand new system with no stock, production capacity had to be massively expanded (-> Diehl Defence expands Nonnweiler site).
- Diehl tripled its missile production in 2023.
- The target for 2024 was a further doubling.
- According to available information, 658 Iris T missiles had already been delivered to Ukraine by February 2025.
However, this high number also makes it clear that no missile battery fires indiscriminately at targets. Instead, targets are prioritized and, where possible, assigned to more cost-effective defence systems.
At the International Aerospace Exhibition in Berlin 2024 (ILA), the focus was on further investments.
In order to meet the increasing demand for air defence systems and missiles, Diehl Defence is planning infrastructure measures worth around one billion euros in the coming years. These investments are intended to significantly expand production capacities and ensure long-term delivery capability.
The situation in Austria
Despite being mentioned in the National Defense Report 2023, the support of EDIRPA and membership in the ESSI, the Austrian Armed Forces has not yet officially made a decision on the procurement of a medium-range air defense system.
Based on a list of around 15 systems, experts evaluate the advantages and disadvantages of each individual candidate. It is highly likely that the group of favorites will be narrowed down to the following systems:
- the British-Italian CAMM from MBDA,
- the US-Norwegian NASAMS from Kongsberg,
- the French MICA GL,
- the Israeli Barak MX (last procured by Slovakia),
- and IRIS-T.
Both military-technical and operational issues need to be clarified, including integration into the army’s existing sensor and data network, as well as suitability for the geographical and meteorological conditions prevailing in Austria.
In addition, economic and foreign policy factors also play a decisive role. Only after careful consideration of these factors can a final procurement decision be made at the highest level.
