Brimstone Anti-Armour Missile, United Kingdom

The Brimstone advanced anti-armour missile has been developed by MBDA (formerly Alenia Marconi Systems) with Boeing as the primary subcontractor. The high performance system entered a pre-production development program in 1996. It began quantity production in late 2004.

The Brimstone weapon system entered service with initial operational capability (IOC) on the UK Royal Air Force Tornado GR.Mk4 aircraft in March 2005. Following a series of highly successful batch and service evaluation trials, full operational capability (FOC) was achieved in December 2005.

Brimstone has been operationally deployed on Tornado GR4 aircraft in Iraq and, from early 2009, will be deployed in Afghanistan.

In May 2008, the UK RAF issued an urgent operational requirement for an upgrade to the Brimstone dual-mode seeker to give the missile system a 'man-in-the-loop' capability to reduce the possibility of collateral damage.

Brimstone can be ground launched or air launched. Ground-launched missile firings have been successfully carried out for example at the Yuma Proving Grounds in Arizona. The system can be fired from fixed or mobile ground launchers and was proposed for installation on the future UK Tracer armoured scout and reconnaissance vehicle, before that project was cancelled.

The air-launched Brimstone meets and exceeds the Royal Air Force requirements for a long range anti-armour weapon giving fighter aircraft the stand-off capability of killing tanks and armoured assets deep behind enemy lines. Brimstone is being integrated into the RAF fleet of Harrier GR7, GR9, Tornado GR4, GR4A and Eurofighter Typhoon aircraft and will replace RBL 755 cluster bombs. The small size and weight of Brimstone allows it to be integrated onto a wide range of helicopters and fixed-wing aircraft for example L-159, Hawk and F/A-18.

Fire and forget

Brimstone is a fully fire-and-forget system, requiring no further interaction from the launch platform nor a post-launch target designator.

After leaving the launcher the solid propellant rocket motor accelerates the missile to supersonic speed. The solid propellant motor has a short burn time and very low smoke emission. This gives a very low visual and infrared signature minimising the probability of detection by hostile sensors.

Seeker

Brimstone is equipped with a small robust millimetric wave radar seeker operating at 94GHz, giving the capability to operate in all weathers and by day and night. The seeker operates in low visibility, contaminated battlefield conditions and is not susceptible to battlefield obscurants such as smoke, dust, flares and chaff.

The high-millimetric band seeker provides a high-resolution radar return image of the target. The high frequency gives a small beamwidth and therefore very high angular resolution and reduced unwanted clutter for the given antenna size, which is limited by the diameter of the missile.

The millimetre wave radar gives wide band operation allowing the use of very sophisticated electronic counter-countermeasures. Millimetric radar attenuates more rapidly than conventional centemetric radar in rain, sleet and fog but its advantage is high penetration, in comparison to infrared sensor systems when countermeasures are employed. The seeker incorporates a terrain avoidance capability, allowing it to cruise at a fixed height above the ground.

A digital autopilot provides mid-course guidance. The digital autopilot with a high accuracy digital inertial measurement system provides the high precision navigation to locate targets at long range and in off-boresight operations. The highly advanced guidance system on the launcher's fire control unit and on the missile uses the target coordinates, course and speed, distance to target, missile trajectory data and data from other sensors to direct the missiles controls and accomplish the optimum flight path to the target.

Salvo firing

In the case of a group of hostile armoured vehicles being identified on the battlefield, multiple launch of Brimstone missiles can be fired in salvo. The missiles can fly out from a single platform to spread out and cover a large area.

Where hostile forces have in-line formations of armoured vehicles, the Brimstone missiles can be flown down the same corridor to attack the formation. Engagement algorithms resident in the on-board computer reduce the probability of more than one missile hitting the same target. The fire command and control system can allocate individual missiles to engage sequentially numbered valid targets.

Damage control

During the search phase of the missile flight, the millimetre wave seeker carries out a sweep search for targets on the ground directly ahead and to each side of its path.

For low collateral damage control the missile can be programmed not to initiate target search until it has passed a given point. This allows Brimstone to safely overfly friendly forces. Similarly, Brimstone can be programmed to cease target search beyond a determined engagement area or to accept a target only within a specified area.

Embedded algorithms allow Brimstone to attack only valid targets within a specified area. The high selectivity allows Brimstone to target armoured vehicles and ignore other fixed or moving assets, such as houses or cars. It is possible to program the missile to engage targets with a specific radar signature, for example patrol boats.

The missile is also fitted with a programmable self-destruct mechanism.

Warhead

Brimstone is armed with a tandem high explosive anti-tank warhead capable of penetrating explosive reactive armour (ERA).

The front charge initiates the explosion of the reactive armour and clears the path for the main charge to penetrate the armour with the high explosive anti-tank jet dart.