Exocet AM39 / MM40 / SM39

Exocet AM39 is the airborne version of the Exocet anti-ship missile family. It can be launched from strike aircraft, Maritime Patrol Aircraft and helicopters. With a range of up to 70 km, depending on the altitude and speed of the aircraft, the Exocet AM39 enables the aircraft to remain at range from enemy air defences. When carrying out a low altitude attack, the missile may also be launched under the target ship radar coverage. Ingress is at a very low altitude over the sea (sea skimming).

Exocet SM39 is the submarine-launched version of the Exocet family. It features all weather capability, sea skimming flight, solid propellant and a high kill warhead. The missile has a range of 50 km, which enables the submarine to go into action while remaining out of enemy detection and weapon range. Flexibility and versatility are provided thanks to the system’s large launch envelope. Housed in a water-tight, highly resistant, propelled and guided underwater vehicle, the aerial missile is ejected as soon as it breaks the surface, to ensure a very low culmination altitude. It then rapidly homes into the target at sea skimming level: it uses an inertial navigation system followed by autonomous terminal guidance from an active RF seeker.

The Exocet MM40 Block 3 weapon system is the latest generation ship-borne version of the Exocet family and is in operational service with several navies. Exocet MM40 Block 3 provides enhanced operational performance and technology upgrades, while minimising the impact on procurement and logistic support costs. Exocet MM40 Block 3’s Mission Planning software module automatically computes engagement plans to support firing decisions.

The flexibility of the Exocet MM40 Block 3 weapon is further enhanced by the accuracy of the new navigation package, allowing optimised 3D approach trajectories and terminal attacks from different azimuths, at very low sea skimming altitude with simultaneous time on target. The terminal guidance relies on a sophisticated J-band active seeker to discriminate and select targets at sea and on the GPS accuracy for land targets.

Exocet MM40 Block 3 is compatible with most of the logistic support assets already in service. Its launching system is interoperable with all MM40 versions, thus enabling a smooth transition to Block 3.

Basically, the design of the rocket was similar to the design of the earlier rocket of the Nord company - AS.30 of the air-to-ground class. The Exocet has four clipped delta wings at mid-body and four raked clipped-tip moving delta control fins at the rear. The rocket has a normal aerodynamic configuration with a cruciform wing in the middle part of the cylindrical body and the same steering wheels on the surface of the tail section.

The missile is 4.7 m long, has a body diameter of 350 mm and a wingspan of 1.1 m. The missile weighs 670 kg and has a 165 kg HE shaped charge fragmentation warhead. Guidance in the mid-course phase is inertial, followed by an active radar terminal phase. There is also a radar altimeter to control the sea-skimming trajectory, at around 10.0 m until the terminal phase when, in calm sea conditions, the missile can descend to 3.0 m or so. The solid propellant motor gives Exocet a range of about 50 km, but when released from 10,000 m (32,800 ft) the range achieved was reported to be 70 km.

All variants of Exocet missiles are equipped with inertial control system, radio altimeter and active radar pulse homing head (ARGSN). The inertial platform has two gyros and three accelerometers. ARGSN MM-39 with horizontal stabilization of the radiation pattern with a mass of about 30 kg operates at a frequency of 8-10 GHz. ARGSN is capable of detecting a “frigate” type ship with an effective scattering surface of about 100 sq. M at a distance of up to 24 km. The antenna searches for a target in the sector ± 16 ° in azimuth and ± 10 ° in elevation. The homing heads of all missile variants can capture a target (including a small one) that has a speed of up to 40 knots, regardless of the autonomous flight duration and the accuracy of preliminary target designation data. High-explosive fragmentation warhead (warhead) with a large number of fragments, unified for all variants of the Exocet rocket, has contact and non-contact fuses. Mass of explosives warhead 165 kg. The highest efficiency of the warhead is achieved at meeting angles with a target of about 70°.

The Exocet missile, which equips the French navy with three versions - seato-sea, airto-sea and sub-sea - currently suffer from several operational shortcomings. Not only are current stocks relatively low, the Exocet missile’s speed remains subsonic, while its range is limited to a few tens of kilometers. However, the latest model of the sea-to-sea version of the missile (MM 40 Block 3) has improved overall performance by enabling, through the use of a turbojet engine, a firing range of 180 kilometres and a transonic velocity (Mach 0.9). Starting in 2019, a new version with a more precise homing missile for improved target acquisition, and more resilient to adverse interference, will be rolled out. This future missile, called MM40 Block 3C, will guarantee its holders the ability to respond to the evolution of the threat over the next ten to fifteen years. In addition, France’s Military Program Law 2019–2025 had planned obsolescence management work on the air-to-sea and sub-sea versions of Exocet to maintain this missile generation until the 2030s.