Cruise missile

A cruise missile is a guided missile which uses a lifting wing and most often a jet propulsion system to allow sustained flight. Cruise missiles are, in essence, unmanned aircraft. 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 high subsonic speeds, are self-navigating, and fly low in order to avoid radar detection.

Concise history

The first cruise missile developed was the Kettering Bug, developed 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 not used offensively, 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 South Korea and Taiwan. 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.

The Soviet Union was especially fond of large cruise missiles. The United States had a program to develop a nuclear-powered cruise missile, Project Pluto. Although the concept was proven sound, none were ever test-launched. 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.

Design

Missions

The most common mission is to attack relatively high value targets such as ships, command bunkers, bridges and dams. Modern guidance system permit precise attacks. Cruise missiles are well-suited to assassination, but the USA has gradually shifted towards the routine use of UAVs for carrying out assassinations, with many assassination attempts against heads of state such as Mullah Omar of Afghanistan and Saddam Hussein of Iraq, using both cruise missiles and UAVs .

Warhead

Most cruise missiles carry about 500 kg of explosives, because most were designed to sink ships and destroy bunkers.

See Nuclear Weapon, Explosives.

Aerodynamics

See Aircraft, Aerodynamics, Wing

Engine

See Jet engine, Ramjet

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. Anti-ship cruise missiles like the RGM-84 Harpoon or the SS-N-12 Sandbox may also employ infrared or radar guidance.

Main cruise missile versions

Conventionally armed

(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.

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. China has also designed several cruise missile variants, many dedicated to naval attack.

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. However, Russia developed and tested new, X-555 cruise missile with maximum range of 3500 km and more advanced target seeker and battle section.

Criticism

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, not to mention the intrinsic value of human life (of the attackers).

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 . He later claimed that his tax problems were the result of a government attempt to shut him down.

External links

An introduction to cruise missiles – From the website of the Federation of American Scientists (FAS)
The DIY cruise missile
ACT for Disarmament
How Cruise Missiles Work
The W80 Warhead

Cruise missiles | Missile types | Unmanned vehicles

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