The new variant, designated SM40 by the company, is a cut-down version of the latest ship-launched MM40 Block 3c modified for encapsulated launch from a submarine torpedo tube.
MBDA says the proposed development, which would succeed the legacy SM39 in the Exocet family portfolio, has arisen from discussions with the Direction générale de l’armement and the French Navy, while also reflecting demand from Naval Group for a new sub-launched anti-ship cruise missile to support export submarine sales.
The SM39 version of Exocet retains the solid-rocket propulsion stack of earlier generation Exocet weapons – limiting range to around 50 km – and also retains an older navigation and guidance ‘front-end’. It has thus become increasingly difficult to manufacture, and less relevant to current operating environments.
Feasibility studies and initial engineering development performed by MBDA have sought to leverage from the latest MM40 Block 3c version of Exocet, deliveries of which began to the French Navy in late 2023. The Block 3c weapon introduces a ‘digitised’ avionics package – including a new Thales-built coherent active radar seeker – into the existing turbojet-powered, 200 km-range Block 3 airframe.
The new coherent seeker and associated algorithms implement adaptive search patterns and metric resolution. This provides for significant improvements in both all-weather target selectivity and electronic counter-countermeasures performance. Alongside the seeker upgrade, Block 3c also introduces a digital radar altimeter, and a new GPS receiver (embedded in the weapon controller).
According to MBDA, SM40 would adapt the MM40 Block 3c baseline for submarine launch, but introduce design changes in order to use the same encapsulation as SM39 and so reduce development and integration costs. To achieve this, SM40 would marry the Safran TR-40 turbojet engine and avionics package of Block 3c with a shortened airframe so that the weapon can fit inside the torpedo tube launch capsule. The missile wings would also be modified for encapsulation.
The smaller airframe reduces fuel capacity relative to the ship-launched MM40 Block 3/3c. However, MBDA believes that SM40 will still achieve a range of 120 km, which is double that of its predecessor. Furthermore, SM40 will maintain the existing SM39 launch envelope, which includes the ability to launch from deep. As the MM40 Block 3/3c, the new missile can strike coastal targets (such as moored ships inside a naval base). In addition, Naval News understands that MBDA envisions additional target sets for the SM40.
Story by Richard Scott, video interview by Xavier Vavasseur.
