BGM-109 Tomahawk

The Tomahawk Land Attack Missile (TLAM) is a long-range, all-weather, subsonic cruise missile. Introduced by General Dynamics in the 1970s, it was designed as a medium- to long-range, low-altitude missile that could be launched from a submerged submarine. It has been improved several times and, by way of corporate divestitures and acquisitions, is now made by Raytheon. Some Tomahawks were also manufactured by McDonnell Douglas.

Description
The Tomahawk missile family consists of a number of subsonic, jet engine-powered missiles for attacking a variety of surface targets. Although a number of launch platforms have been deployed or envisaged, only naval (both surface ship and submarine) launched variants are currently in service. Tomahawk has a modular design, allowing a wide variety of warhead, guidance and range capabilities.

Variants
There have been several variants of the BGM-109 Tomahawk employing various types of warheads.
 * BGM-109A Tomahawk Land Attack Missile - Nuclear (TLAM-N) with a W80 nuclear warhead - withdrawn from service
 * RGM/UGM-109B Tomahawk Anti Ship Missile (TASM) - radar guided anti-shipping variant
 * BGM-109C Tomahawk Land Attack Missile - Conventional (TLAM-C) with a unitary warhead
 * BGM-109D Tomahawk Land Attack Missile - Dispenser (TLAM-D) with submunitions
 * RGM/UGM-109E Tomahawk Land Attack Missile (TLAM Block IV) - improved version of the TLAM-C
 * BGM-109G Gryphon Ground Launched Cruise Missile (GLCM) - withdrawn from service
 * AGM-109H/L Medium Range Air to Surface Missile (MRASM) - a shorter range, turbojet powered ASM, never entered service

Ground Launch Cruise Missiles (GLCM) and their truck-like launch vehicles were destroyed to comply with the 1987 Intermediate-Range Nuclear Forces Treaty. Many of the Anti-ship versions were converted into TLAMs at the end of the Cold War. The Block III TLAMs that entered service in 1993 can fly farther and use Global Positioning System (GPS) receivers to strike more precisely. Block IV TLAMs have a better Digital Scene Matching Area Correlator (DSMAC) system as well as improved turbofan engines. The WR-402 engine provided the new BLK III with a throttle control, allowing in-flight speed changes. This engine also provided better fuel economy. The Block IV Phase II TLAMs have better deep-strike capabilities and are equipped with a real-time targeting system for striking moving targets.

Tactical Tomahawk
A major improvement to the Tomahawk is its network-centric warfare-capabilities, using data from multiple sensors (aircraft, UAVs, satellites, foot soldiers, tanks, ships) to find its target. It will also be able to send data from its sensors to these platforms. It will be a part of the networked force being implemented by the Pentagon.

”Tactical Tomahawk” equips the TLAM with a TV-camera for battlefield observation loitering that allows warfighting commanders to assess damage to the target and to redirect the missile to an alternative target. Additionally the Tactical Tomahawk is able to be reprogrammed in-flight to attack one of 16 predesignated targets with GPS coordinates stored in its memory or to any other GPS coordinates. Also, the missile can send data about its status back to the commander. It entered service with the Navy in late 2004.

On May 2009, Raytheon Missile Systems proposed an upgrade to the Tomahawk Block IV land-attack cruise missile that would allow it to kill or disable large, hardened warships at 900 nm range.

Launch systems
Each missile is stored and launched from a pressurized canister that protects it during transportation and storage and acts as a launch tube. These canisters are racked in Armored Box Launchers (ABL), as on the battleship Missouri, Vertical Launch Systems (VLS) in other surface ships, Capsule Launch Systems (CLS) in the later Los Angeles class submarines, and in submarines' torpedo tubes. All ABL equipped ships have been decommissioned.

For submarine-launched missiles (called UGM-109s), after being ejected by gas pressure (vertically via the VLS) or by water impulse (horizontally via the torpedo tube), the missile exits the water and a solid-fuel booster is ignited for the first few seconds of airborne flight until transition to cruise. After achieving flight, the missile's wings are unfolded for lift, the airscoop is exposed and the turbofan engine is employed for cruise flight. Over water, the Tomahawk uses inertial guidance or GPS to follow a preset course; once over land, the missile's guidance system is aided by Terrain Contour Matching (TERCOM). Terminal guidance is provided by the Digital Scene Matching Area Correlation (DSMAC) system or GPS, producing a claimed accuracy of about 10 meters.



The Tomahawk Weapon System consists of the missile, Theater Mission Planning Center (TMPC)/Afloat Planning System, and either the Tomahawk Weapon Control System (on surface ships) or Combat Control System (for submarines).

Several versions of control systems have been used, including:


 * v2 TWCS - Tomahawk Weapon Control System (1983), also known as "green screens," was based on an old tank computing system.
 * v3 ATWCS - Advanced Tomahawk Weapon Control System (1994), first Commercial Off the Shelf, uses HP-UX.
 * v4 TTWCS - Tactical Tomahawk Weapon Control System, (2003).
 * v5 TWCS - Next Generation weapon control system. (2006)

Other details
The TLAM-D contains 166 sub-munitions in 24 canisters; 22 canisters of seven each, and two canisters of six each to conform to the dimensions of the airframe. The sub-munitions are the same type of Combined Effects Munition bomblet used in large quantities by the U.S. Air Force. The sub-munitions canisters are dispensed two at a time, one per side. The missile can perform up to five separate target segments which enables it to attack multiple targets. However in order to achieve a sufficient density of coverage typically all 24 canisters are dispensed sequentially from back to front.

TERCOM - Terrain Contour Matching. A digital representation of an area of terrain is mapped based on digital terrain elevation data or stereo imagery. This map is then inserted into a TLAM mission which is then loaded on to the missile. When the missile is in flight it compares the stored map data with radar altimeter data collected as the missile overflies the map. Based on comparison results the missile's inertial navigation system is updated and the missile corrects its course.

DSMAC - Digital Scene Matching Area Correlation. A digitized image of an area is mapped and then inserted into a TLAM mission. During the flight the missile will verify that the images that it has stored correlates with the image it sees below itself. Based on comparison results the missile's inertial navigation system is updated and the missile corrects its course.


 * Total program cost: $11,210,000,000.00

United States Navy
In the 1991 Persian Gulf conflict, 288 Tomahawks were launched. The first salvo was fired by the cruiser USS San Jacinto on January 17, 1991. The attack submarines USS Pittsburgh and USS Louisville followed. The Louisville Slugger company gave the crew of the latter special-edition baseball bats emblazoned with an image of the submarine conducting a Tomahawk launch. The honor was repeated during Operation Iraqi Freedom. The United States Navy has a stockpile of around 3,500 Tomahawk cruise missiles of all variants.

Royal Navy
The United States agreed to sell more than 60 Tomahawks to the United Kingdom in 1995 for use with Royal Navy nuclear submarines. The first missiles were acquired and test-fired in 1998.

It is in use with the Swiftsure class and Trafalgar class attack submarines. It is planned that all Royal Navy submarines will be Tomahawk capable by 2008, including the future Astute class attack submarine.

In 2004, the UK and US governments reached an agreement for the British to buy 64 of the new generation of Tomahawk missile – the Block IV or TacTom missile. The SYLVER vertical launch system to be fitted to the new Type 45 destroyer is claimed by its manufacturers to have the capability to fire the Tomahawk. Therefore it would appear that Tomahawk is a candidate to be fitted to the Type 45 if required. France, which also uses the SYLVER launcher, is developing a version of the Storm Shadow/Scalp cruise missile capable of launch from the SYLVER system, which would give a similar land attack capability.

The Kosovo War in 1999 saw HMS Splendid become the first British submarine to fire the Tomahawk in combat. It has been reported that seventeen of the twenty Tomahawks fired by the British during that conflict hit their targets accurately. The Royal Navy later used them in the 2001 Afghanistan War and Operation Telic, the British contribution to the 2003 Iraq War.

The Royal Navy has recently purchased the Block IV tomahawk which entered service as of the 27th March 2008, three months ahead of schedule.

Spanish Navy
In July 2006, the United States Congress authorized Spain to buy Tomahawk missiles. The number of missiles to be purchased will be between 60 and 100. The missiles will be used in the AEGIS Álvaro de Bazán Class Frigates and in the new S80 submarines. The missiles will be delivered between 2008 and 2012.