Cruise missile

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Image:Tomahawk Block IV cruise missile.jpg A cruise missile is a guided missile which uses a lifting wing and most often a jet propulsion system to allow sustained flight. A Cruise missile is, in essence, a flying bomb. They are generally designed to carry a large conventional or nuclear warhead many hundreds of miles with excellent accuracy. Modern cruise missiles normally travel at supersonic and at high subsonic speeds, are self-navigating, and fly in a non-ballistic very low altitude trajectory in order to avoid radar detection. In general (and for the purposes of this article), cruise missiles are differentiated from unmanned aerial vehicles (UAV) in that the weapon is integrated into the vehicle, and the vehicle is intended to be sacrificed in the mission. Cruise missiles are also frequently fired from specialized warships called cruisers, which adds to the name's validity.

1 Concise history
2 Design
3 Cruise missile categories
4 Employment of cruise missiles
- 4.1 Nuclear warhead versions
- 4.2 Efficacy of cruise missiles in modern warfare
5 Trivia: A "DIY" cruise missile
6 See also
7 External links

[edit] Concise history

The first cruise missile developed was the Kettering Bug, developed by the U.S. in 1917 for use in World War I. This used a biplane configuration, and flew in a straight line for a predetermined time, at which point the wings were detached and the fuselage, containing the warhead, fell to the ground. It was never used in service, as World War I ended before it was deployed.

Cruise missiles were first employed by Nazi Germany during World War II. Introduced in 1944, the V-1 was the first weapon to use the classic cruise missile layout of a bomb-like fuselage with short wings and a dorsally mounted engine, along with a simple inertial guidance system. The V-1 was propelled by a crude pulse-jet engine, the sound of which gave the V-1 its nickname of "buzz bomb". However, the V-1 did not have the level of accuracy of a modern tactical cruise missile. The V-1 and similar early weapons are often referred to as flying bombs. Japan, in an effort to gain a tactical advantage against the allied forces resorted to kamikaze aircraft, such as the purpose-built Ohka, another early predecessor to the super-accurate cruise missiles of today.

During the Cold War, both the United States and the Soviet Union experimented further with the concept, deploying early cruise missiles from land, submarines and aircraft.

The main outcome of the U.S. Navy submarine missile project was the SSM-N-8 Regulus missile, based upon the V-1.

The U.S. Air Force's first operational surface-to-surface missile was the winged, mobile, nuclear-capable MGM-1 Matador, also similar in concept to the V-1. Deployment to overseas operating locations began in 1954. The Matador was first deployed to West Germany and then later to the Republic of China (Taiwan) and South Korea. On November 7, 1956, U. S. Air Force Matador units in West Gemany, whose missiles were capable of striking targets in the Warsaw Pact, deployed from their fixed day-to-day sites to unannounced dispersed launch locations. This alert was in response to the crisis posed by the major Soviet attack on Hungary which brutally suppressed the Hungarian Revolution.

Between 1957 and 1961 the United States followed an ambitious and well-funded program to develop a nuclear-powered cruise missile, Project Pluto. It was designed to fly below the enemy's radar at speeds above Mach 3 and carry a number of hydrogen bombs that it would drop on its path over enemy territory. Although the concept was proven sound and the 500 megawatt engine finished a successful test run in 1961, no airworthy device was ever completed. The project was finally abandoned in favor of ICBM development.

While ballistic missiles were the preferred weapons for land targets, heavy nuclear and conventional tipped cruise missiles were seen by the USSR as a primary weapon to destroy US carrier battle groups. Large submarines (e.g. Echo and Oscar classes) were developed to carry these weapons and shadow US battle groups at sea, and large bombers (e.g. Backfire, Bear, and Blackjack models) were equipped with the weapons in their air launched cruise missile (ALCM) configuration.

[edit] Design

Image:Brahmos.gif

[edit] Warhead

Most cruise missiles carry about 500 kg of explosives, because most were designed to sink ships and destroy bunkers. Some may also carry a nuclear warhead.

[edit] Aerodynamics

The aerodynamics of a cruise missile are quite similar to those of an airplane, including the use of wings.

[edit] Engine

Most cruise missiles are propelled by a jet engine, with a ramjet engine being the most common due to its simplicity.

[edit] Guidance

The lowest cost system in wide use uses a radar altimeter, barometric altimeter and clock to navigate a digital strip map. Some systems may now use satellite navigation or inertial guidance, but these are substantially more expensive, and GPS systems are only slightly more accurate than a map-based system (TERCOM). Anti-ship cruise missiles like the RGM-84 Harpoon or the SS-N-12 Sandbox may also employ infrared or radar guidance.

[edit] Cruise missile categories

Cruise missiles can be categorized according to many criteria. It is convenient to categorize them by size, speed (subsonic or supersonic), and range. Often, the same missile is adopted for different launch platforms (land, sea, or air). Sometimes, the air- and submarine-launched versions are a bit lighter and smaller than their land- and ship-launched cousins.

Guidance systems can vary across missiles, but often the same missile comes in several variants, each with a different navigation system (Inertial navigation,TERCOM, or satellite navigation). Larger cruise missiles can carry either a conventional or a nuclear warhead, while smaller ones carry only conventional warheads.

[edit] Large long-range subsonic cruise missiles

This is a popular category for cruise missiles. Several missiles of this type were developed by the United States and the Soviet Union. These missiles have a range of 1,000 or more kilometers and fly at about 800km/h. The missiles in this category typically have a launch weight of about 1,500kg. These missiles can carry either a conventional or a nuclear warhead. Earlier versions of these missiles had inertial navigation. Later, TERCOM and DSMAC systems were added to dramatically improve accuracy. Most recent versions can use satellite navigation.

Examples:

AGM-86B (United States)
BGM-109 Tomahawk (United States)
Kh-55 Granat (USSR)

[edit] Large medium-range subsonic cruise missiles

These missiles are about the same size and weight as the above category. They also travel at about the same speed, but the range is less than 1,000km. Guidance systems vary.

Examples:

Storm Shadow (UK/France)
Taurus (Germany/Sweden)
Babur (Pakistan)

[edit] Supersonic cruise missiles

These missiles travel faster than the speed of sound, usually using ramjet engines. The range is typically 100-500km, but can be greater. Guidance systems vary.

Examples:

SLAM and SM-64 Navaho were U.S. early-cold-war era projects for strategic long-range cruise missiles. Neither was accepted into service.
P-500 Bazalt (Soviet Union/Russia)
P-270 Moskit (Soviet Union/Russia)
P-800 Oniks (Soviet Union)
P-700 Granit (Soviet Union/Russia)
PJ-10 BrahMos (India/Russia)

[edit] Smaller cruise missiles

These missiles weigh around 500kg and have range of 70-300km. Their speed is subsonic. Navigation systems are usually more simple than those of larger missiles. In fact, the word "cruise" is not always applied to these missiles.

Examples:

AGM-84 Harpoon (United States)
C-802 (China)
Exocet (France)
SS-N-25 Switchblade (Kh-35 Uran) (Russia)
RBS15 (Sweden/Germany)
Babur Missile (Pakistan)

[edit] Employment of cruise missiles

The most common mission for cruise missiles is to attack relatively high value targets such as ships, command bunkers, bridges and dams. Modern guidance system permit precise attacks.

(As of 2001) the BGM-109 Tomahawk missile model has become a significant part of the US naval arsenal. It gives ships and submarines an extremely accurate, long-range, conventional land attack weapon. Each costs about $1,900,000 USD. The US Air Force deploys an air launched cruise missile, the AGM-86. It can be launched from bombers like the B-52 Stratofortress. Both the Tomahawk and the AGM-86 were used extensively during Operation Desert Storm. The British Royal Navy (RN) also operates cruise missiles, specifically the Tomahawk, used by the RN's nuclear submarine fleet. Conventional warhead versions were first fired in combat by the RN in 1999, during the Kosovo War.

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Both Tomahawk (as AGM-109) and ALCM (AGM-86) were originally developed as competing designs for the USAF ALCM nuclear tipped cruise missile competition. The USAF adopted the AGM-86 for its bomber fleet while AGM-109 was adapted to launch from trucks and ships and adopted by the USAF and Navy. The truck launched versions were later destroyed under the bilateral INF (Intermediate Range Nuclear Forces) treaty with the USSR which also saw the end of the Pershing II and SS-20 Intermediate Range Ballistic Missiles.

India and Russia have jointly developed the supersonic cruise missile BrahMos. There are three versions of the Brahmos: ship/land-launched, air-launched and sub-launched. The ship/land-launched version is operational whereas the air-launched and sub-launched versions are under development. The Brahmos has the capability to attack targets on land. The UK and France operate the Storm Shadow, Germany and Sweden the Taurus missile while Pakistan has developed its own cruise missile somewhat similar to Tomahawk cruise missile, named the Babur missile. Both the People's Republic of China and the Republic of China (Taiwan) have also designed several cruise missile variants, some of which are capable of carrying biological, chemical, nuclear, and conventional warheads.

[edit] Nuclear warhead versions

The US has 460 AGM-129 Advanced Cruise Missiles (ACMs) with a W80 nuclear warhead (5KT or 150KT selectable yield) for B-52 Stratofortress (B-52H) external carriage. Also there are ca. 350 sea launched cruise missiles with the same nuclear warhead. The range of the missile is 3000 km. They all remain in storage.

See also:

Russia has Kh-55SM cruise missiles, with similar to US AGM-129 range of 3000 km, but are able to carry more powerful warhead of 200 kt.

[edit] Efficacy of cruise missiles in modern warfare

Cruise missiles are among the most expensive of single-use weapons, up to several million dollars apiece. One consequence is that the users face difficult choices in targeting, to avoid expending the missiles on targets of low value. For instance, Operation Enduring Freedom, the United States struck targets of very low monetary value with cruise missiles, which led many to question the efficiency of the weapon. However, the same counterargument applies to cruise missiles as to other types of UAVs, which is that cruise missiles are still cheaper than human pilots when total training and infrastructure costs are taken into account^{[citation needed]}, not to mention the intrinsic value of human life (of the attackers).

[edit] Trivia: A "DIY" cruise missile

There was also a project by a New Zealander named Bruce Simpson to design and test fly a home-built cruise missile. It was funded by private investors, and it was planned to be built for under $5,000, which is remarkably cheaper than the approximate 1.9 million USD used to build the Tomahawk.

Simpson intended to use readily available components to build a basic missile system. His extensive experience in the building of radio controlled model aircraft would be employed in airframe and control surface design. A commercially available Global Positioning System (GPS) unit linked to a standard programmable logic controller (PLC) unit running custom developed software would be used for guidance and control. Propulsion would come from a pulse jet engine of his own design.

Payload was intended to be in the region of 10–15 kilograms, which is not enough to do significant damage if loaded with conventional explosives but sufficient to be used as a dispersal system for biological/chemical agents.

In late 2003, however, Simpson ran into tax difficulties, and ended the project ^{[citation needed]}. He later claimed that his tax problems were the result of a government attempt to shut him down.