The Lightweight Multirole Missile (LMM) is a lightweight air-to-surface and surface-to-surface missile under development by Thales Air Defence for the United Kingdom. LMM is a low cost, lightweight, precision strike, missile, which has been designed to be fired from tactical platforms including fixed or rotary winged UAVs and surface platforms. The system is designed to provide a rapid reaction to a wide range of the surface threats from wheeled or tracked vehicles, towed artillery or static installations; naval threats from small ships and fast inshore attack craft and an air threat from light aircraft. The UK Ministry of Defence (MoD) has placed an initial order for 1,000 missiles and deliveries were due to start in 2013.The missile is known as Martlet in British service. The LMM missile’s propulsion system consists of a two-stage rocket motor. It has a velocity of more than Mach 1.5 and an operational range between 6km and 8km, while the minimum range is 400m.
The missile, sealed in its canister, consists of a two stage motor, warhead and dual mode fuze, together with guidance electronics and a highly
accurate control actuator system. The low cost, covert, flexible LMM missile features soft launch design and has a shelf life of 15 years. It has immediate launch, high lethality, as well as fire on-the-move capabilities. The missile measures 1.3m in length, 0.26m in wing span, and 76mm in diameter. It has a maximum weight of 13kg. It is equipped with a modular shaped charge / pre-fragmented blast warhead, which weighs up to 3kg. The warhead is activated by a highly sensitive laser proximity fuse. The versatile design of the weapon system allows it to be configured to function as an all-in-one weapon system for larger naval platforms and as a hybrid missile / gun system fitted with LMM and integrated with naval guns. It can also be customised for integration on a fast patrol boat.
Guidance for the LMM missile is provided from an optical tracker system attached to the launch platform. The missile can be operated in multiple secure guidance modes including laser beam riding, automatic guidance and laser designation to ensure precision attack of targets with man-in-the-loop. It can also be equipped with IR terminal homing guidance with INS and GPS navigation, as well as semi-active laser guidance. The guidance section is part of an optically stabilised mount, featuring charge-coupled device (CCD) and thermal cameras connected with an automatic target tracker (ATT) and missile laser guidance unit. On target indication, the weapon operator acquiresthe target in the display monitor. The ATT is directed onto the target by the operator and he engages the ATT, which locks a box around the threat. When the target is within range the operator selects ‘System On’ and presses the firing trigger. The missile is launched and guided automatically to the target.
LMM is intended to provide a single family of weapons that can be used in different modes, including:
- Maritime – LMM will be carried on the new Lynx Wildcat helicopters of the Royal Navy for use against small surface vessels. ASELSAN of Turkey has developed dedicated mounting systems which can also enable the LMM to be launched from naval platforms such as fast attack craft (FAC).
- Surface-To-Surface – The dual-effect (blast fragmentation and shaped charge) of the LMM’s warhead makes it suitable for use against a wide range of ground targets including light/medium armour.
- Air-Launched – The missile’s modular design allows for future development and introduction of alternative warheads and seekers.
LMM was initially conceived as Thales’ response to the MoD’s Future Air-to-Surface Guided Weapon (Light) FASGW(L) requirement. The FASGW-L missile system consists of five barrel launchers and a laser guidance system. LMM has been designed to be launched from a variety of naval, air and land platforms against a wide range of targets. In July 2014, Thales unveiled a modification of the LMM that turns it into a glide bomb, called the FreeFall LMM (FFLMM). Thales partnered with Textron to market it as the Fury for the U.S. market, who provides a height-of-burst sensor and electronic safe and arm device.