The Brimstone missile was originally called the Advanced Anti -Armour Weapon and was designed to meet the 1982 Staff Requirement (Air) 138 for a stand-off weapon to replace the Hunting Engineering BL755 and RBL755 cluster bombs.
Brimstone was thus designed to defeat massed armoured attacks, ostensibly, Warsaw pact forces in Central Europe. The BL755 was an effective weapon but against newer armour its usefulness was questionable. As part of the Options for Change review, funding was ceased but shortly after, the 1991 Gulf War demonstrated a clear need for a fast jet launched anti-armour weapon and the project was resurrected
In 1994 the Staff Requirement (Air) 1238 was issued, known as the Advanced Anti-Armour Weapon (AAAW)
SR(A) 1238 was very demanding, requiring a completely autonomous weapon that could provide an all-weather, day/night system that could defeat all known armour with a generous margin for future growth. Because of the anti-aircraft weapon density in the likely operating environment, the launching aircraft was required to release the weapon from a safe stand-off distance and at either medium or low altitude, whilst flying at supersonic speeds.
As a final requirement, logistics support and maintenance had to be very simple.
Five submissions were received for the AAAW programme; Thorn EMI, Hunting Engineering, Texas Instruments, British Aerospace Dynamics and GEC Marconi. Hunting Engineering and Texas Instruments both proposed a dispenser with guided sub-munitions, the SWAARM and Griffin 38 respectively. Thorn entered a modified version of the BL755 called TAAWS that used rocket boosted sub-munitions to increase the range and British Aerospace Dynamics proposed a modified version of the ASRAAM air to air missile called Typhoon.
The July 1996 winning bid was submitted by GEC Marconi who teamed with Boeing to create the Brimstone missile. GEC Marconi later became part of Alenia Marconi Systems and in turn was absorbed into MBDA Missile Systems.
Given that studies were initiated in 1982 and a system not selected until 1996, a mere 14 years later, the capability gap was significant.
In Service Date was initially predicted to be 2001.
Initial airborne carriage trials were conducted in 1998 and a year later, firing trials were started in the USA, these unarmed tests being concluded a couple of years later in 2001. Further testing continued in the UK including proving the MIL-STD 1760 interface used to transmit data between the missile and a launch aircraft.
The video below shows later live testing;
A 2002 Parliamentary answer revealed;
The advanced air-launched anti-armour weapon project, BRIMSTONE, has approval to spend up to £849 million, but is currently forecast to spend some £809 million
In 2003, technical problems and launch aircraft availability delayed the in service date
The entry into service of the Brimstone, air launched anti-armour weapon has been delayed because of technical factors that have emerged during the development and trials of the missile and its production. A revised date is currently under review.
Brimstone finally entered service with the RAF on the 31st of March 2005, 23 years after the original work on a replacement for the BL755.
A subsequent 2010 Parliamentary answer revealed the development costs of Brimstone and Dual Mode Brimstone
Quentin Davies (Parliamentary Under-Secretary, Ministry of Defence; Grantham and Stamford, Labour)
The cost of developing the original Brimstone Missile System was £370 million. Dual Mode Seeker (DMS) Brimstone was developed as a variant of the original Brimstone system. Development costs specifically for the DMS variant amounted to about £10 million.
One of Brimstones principal problems was that the world changed around it.
With the Cold War over and the likelihood of massed armour attacks through Germany rather unlikely it was a classic Cold War Dinosaur.
Still, it was a bloody clever one.
Although Brimstone has a common design root as the Hellfire missile it very definitely is NOT a modified Hellfire, with almost no commonality between the two, the guidance fins being the only common component. The G loading, surface friction and speeds involved with supersonic launch made the engineering much more challenging.
The rocket motor accelerates to supersonic speed in less than three seconds and is designed to boost and coast, increasing range and reducing optical and infra-red signatures, which is important when considering counter fire and the deployment of countermeasures. Launch can be from any altitude, including extreme low altitudes.
A triple launching pylon allows three Brimstones to be carried per position and Tornado was designed to carry 4 such pylons. With three weapons fitted the pylon weighs 235kg.
At 48.5kg and 1.8m long it is a compact weapon and has a tandem warhead to defeat reactive armour. The 300g precursor warhead is tilted at a downward angle to make it more effective against reactive armour and the main warhead weighs 6.2kg.
The really clever part of Brimstone though is the guidance system.
Operating at the near optical wavelength of 94 Ghz the radar seeker provides a very high resolution radar image of the target that allows a number of target recognition algorithms to determine whether a return is a tank (and what type) or a tree or building. It is this target recognition that provides the autonomy and allows the launch aircraft to turn away as soon as the weapon is released, leaving the missile to get on with the job. Using a millimetric radar system also confers immunity from target obscuration due to weather and light conditions. The radar has a very narrow emission angle to reduce signatures and the possibility of jamming.
The missile also has a number of attack modes and can exclude low value soft skinned targets, attack vehicle columns in salvos or exclude certain areas. When attacking an area, the multiple missiles in a ripple launch spread out to fly side by side so they impact targets at the same time. If the target is a column the missiles will fly one behind the other, again, all impacting at the same time.
To provide even greater flexibility, the missile can receive targeting information from other platforms, ASTOR for example, proceeding on an indirect flight path to avoid terrain and mask the launch aircraft.
Once launched, the missile is fully autonomous, more on this later.
Part of the development path for the original Brimstone was a different seeker, different warhead and increasing the target set to include maritime targets such as fast attack craft, RIB’s and small patrol vessels. At one stage it was proposed for the Sea Skua replacement. Brimstone was also proposed for the TRACER reconnaissance vehicle programme.
A Brimstone missile costs between £100k and £175k depending on whether development and support costs are included.
At this point it should be clear that Brimstone is a fantastically smart and capable weapon but with a rather limited set of circumstances in which it can be used and so was condemned by many as being wasteful.
In Afghanistan and Iraq, the RAF and FAA found itself without a low yield precision guided weapon with a man in the loop to satisfy stringent rules of engagement. The Maverick missile was available (and used) but it has a large warhead and so an Urgent Operational Requirement was initiated in 2007 that would see earlier plans for an additional guidance system for Brimstone implemented.
This was to be called the Dual Mode Brimstone.
300 first generation Brimstones were converted as part of the UOR (although 500 have now been delivered) with development costs in the order of £10 million.
The Dual Mode modifications include a semi active laser (SAL) seeker head and changes to the software but it retains the radar guidance capability.
The first operational sortie with a Dual Mode Brimstone was by the RAF in Iraq on 18th December 2008 and the first operational firing took place in June 2009 in Afghanistan.
Brimstone was used to excellent effect in Operation Ellamy in Libya where it was for many, one of the stand out weapon systems used.
There were a few minor problems with DM Brimstone but they were quickly resolved.
Since the introduction of DM Brimstone MBDA has also resurrected earlier work on adapting Brimstone for use in the maritime environment. In a privately funded series of trials MBDA have confirmed the ability to use the multiple target engagement radar seeker to target a number of rapidly manoeuvring fast attack craft.
A semi active laser system can only be used for one target at a time which could be a critical issue when dealing with swarming attack craft.
Fitting the three round launcher to helicopters, naval vessels and costal defence sites has also be studied.
Brimstone 2 and SPEAR
In 2011 Dual Mode Brimstone was selected as the basis for the Selected Precision Effects at Range (SPEAR) Capability 2 requirement.
Selected Precision Effects at Range, or SPEAR, is an RAF programme that is part of the 2010 Team Complex Weapons enabling contract that comprises a number of requirements and partners including Thales, MBDA and Roxel among others.
The programmes are;
Fire Shadow Loitering Munition for the Royal Artillery which is expected to begin trials in Afghanistan this year
Future Anti-Surface Guided Weapon (Heavy) is a joint programme with the French for Anti Navire Léger. FASGW (H)/ANL that is expected to arm the Royal Navy’s AW159 Lynx Wildcat helicopter and the French Navy’s NH90 and Panther helicopters.
Selected Precision Effects At Range (SPEAR). SPEAR Capability 2 is a development of the Brimstone Dual Mode Urgent Operational Requirement and SPEAR Capability 3 is a longer range and heavier weapon
Future Anti-Surface Guided Weapon (Light), being developed by Thales Air Defence under the AP to arm the Royal Navy’s AW159 Lynx Wildcat helicopter.
Future Local Area Air Defence System/Common Anti Air Modular Missile has been recently confirmed as armament for the Type 23 frigate and subsequently, called Sea Ceptor, the Type 26. It will also meet the FLAADS (Land) requirement to replace Rapier.
Storm Shadow Capability Enhancement Programme. A joint UK/French joint programme to enhance the Storm Shadow and SCALP cruise missiles
SPEAR Capability 2 is a development of the Dual Mode Brimstone introduced as an Urgent Operational Requirement in 2008. Work for the Block 1 requirement commenced a few years ago but the latest variant will be introduced into service in 2013 as Brimstone 2, this time, into the core equipment programme.
Improvements are said to include an insensitive rocket motor and warhead, longer range, better accuracy, a modular airframe and software enhancements.
The modular design will also improve access to critical components for easier maintenance.
It is hoped of course that this latest development will improve export potential and Brimstone is destined for integration with Typhoon and the Joint Combat Aircraft, both of which should improve its export potential a great deal.
It would be good to see Brimstone 2 integrated with Wildcat and who knows, perhaps one day, it will be used as a Swingfire replacement in the land environment.