Cruise missile

United States/UK Tomahawk cruise missile.
A modern Taurus KEPD 350 cruise missile of the German Luftwaffe

A cruise missile is a guided missile that carries an explosive payload and uses a lifting wing and a propulsion system, usually a jet engine, to allow sustained flight; it is essentially a flying bomb. Cruise missiles are generally designed to carry a large conventional or nuclear warhead many hundreds of miles with high accuracy. Modern cruise missiles can travel at supersonic or high subsonic speeds, are self-navigating, and fly on 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 distinct from unmanned aerial vehicles (UAV) in that they are used only as weapons and not for reconnaissance, the warhead is integrated into the vehicle, and the vehicle is always sacrificed in the mission.

Contents

Concise history

In the period between the World Wars Great Britain developed the Larynx (Long Range Gun with Lynx Engine) which underwent a few flight tests in the 1920s. In the Soviet Union Sergey Korolev headed the GIRD-06 cruise missile project from 1932-1939, which used a rocket-powered boost-glide design. The 06/III (RP-216) and 06/IV (RP-212) contained gyroscopic guidance systems. Germany first deployed cruise style missiles, during World War II. The V-1 contained a gyroscopic guidance system and was propelled by a simple pulse-jet engine, the sound of which gave the V-1 its nickname of "doodlebug". Accuracy was sufficient only for use against very large targets (the general area of a city). The V-1 and similar early weapons are often referred to as flying bombs. Also in World War II the Imperial Japanese forces used piloted aircraft with an explosive payload known as kamikazes, and the purpose-built and piloted rocket engined Ohka.

Immediately after the war the United States Air Force had 21 different guided missile projects including would-be cruise missiles. All were cancelled by 1948 except four: the Air Material Command BANSHEE, the SM-62 Snark, the SM-64 Navaho, and the MGM-1 Matador. The BANSHEE design was similar to Operation Aphrodite; like Aphrodite it failed, and was canceled in April 1949[1].

During the Cold War period 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 overseas began in 1954, first to West Germany and later to the Republic of China (Taiwan) and South Korea. On November 7, 1956 U. S. Air Force Matador units in West Germany, 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 Soviet attack on Hungary which suppressed the 1956 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 U.S. naval carrier battle groups. Large submarines (e.g. Echo and Oscar classes) were developed to carry these weapons and shadow U.S. 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.

Warhead

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

Aerodynamics

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

Engine

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

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.

The use of automatic target recognition algoritihms and devices is increasingly being used to increase the probability of success. The Standoff Land Attack Missile features an ATR unit from General Electric.

Categories

Cruise missiles can be categorized by size, speed (subsonic or supersonic), and range, and whether launched from land, air, surface ship, or submarine. Often versions of the same missile are produced for different launch platforms; sometimes air- and submarine-launched versions are a little lighter and smaller than land- and ship-launched versions.

Guidance systems can vary across missiles. Some missiles can be fitted with any of a variety of navigation systems (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.

Supersonic

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

Examples:

Long-range subsonic

Both the U.S. and the U.S.SR developed several long-range subsonic cruise missiles. These missiles have a range of over 1,000 km and fly at about 800 km/h. They typically have a launch weight of about 1,500 kg, and can carry either a conventional or a nuclear warhead. Earlier versions of these missiles used inertial navigation; later versions use much more accurate TERCOM and DSMAC systems. Most recent versions can use satellite navigation.

Examples:

Medium-range subsonic

These missiles are about the same size and weight and fly at similar speeds to the above category, but the range is (officially) less than 1,000 km. Guidance systems vary.

Examples:

Short-range

These are subsonic missiles which weigh around 500 kg (1,100 lb) and have a range of 70-300 km (40-200 mi). Navigation systems are usually simpler than those of larger missiles. They are not always called "cruise" missiles.

Examples:

Deployment

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 U.S. naval arsenal. It gives ships and submarines an extremely accurate, long-range, conventional land attack weapon. Each costs about $600,000 U.S.D.[2] 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.

Both Tomahawk (as AGM-109) and ALCM (AGM-86) were competing designs for the U.S.AF ALCM nuclear tipped cruise missile to be carried by the B-52 heavy bomber. The U.S.AF adopted the AGM-86 for its bomber fleet while AGM-109 was adapted to launch from trucks and ships and adopted by the U.S.AF and Navy. The truck-launched versions, and also the Pershing II and SS-20 Intermediate Range Ballistic Missiles, were later destroyed under the bilateral INF (Intermediate Range Nuclear Forces) treaty with the U.S.SR.

The British Royal Navy (RN) also operates cruise missiles, specifically the U.S.-made 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. The Royal Air Force uses the Storm Shadow cruise missile on its Tornado GR4 aircraft. It is also used by France, where it is known as SCALP EG, and carried by the Armée de l'Air's Mirage 2000 and Rafale aircraft.

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 were operational as of late 2007. The Brahmos has the capability to attack targets on land. Russia also continues to operate other cruise missiles: the SS-N-12 Sandbox, SS-N-19 Shipwreck, SS-N-22 Sunburn and SS-N-25 Switchblade. Germany and Spain operate 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 designed several cruise missile variants, such as the well-known C-802, some of which are capable of carrying biological, chemical, nuclear, and conventional warheads.

Nuclear warhead versions

SSM-N-8 Regulus

The U.S. has 460 AGM-129 Advanced Cruise Missiles (ACMs) with a W80 nuclear warhead (5 kt or 150 kt 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. These missiles have been "mothballed" and placed in storage.

The SSM-N-8 Regulus was also designed for a nuclear warhead.

See also:

Russia has Kh-55SM cruise missiles, with similar to U.S. AGM-129 range of 3000 km, but are able to carry more powerful warhead of 200 kt. India is developing a cruise missile capable of carrying a 300 kt nuclear warhead to a distance of 1,200 km.[3]

Efficiency in modern warfare

Cruise missiles are among the most expensive of single-use weapons, up to several million dollars apiece. One consequence of this is that its users face difficult choices in targeting, to avoid expending the missiles on targets of low value. For instance during Operation Enduring Freedom the United States attacked targets of very low monetary value with cruise missiles, which led many to question the efficiency of the weapon. However, proponents of the cruise missile counter that the same counterargument applies to cruise missiles as to other types of UAVs: they are cheaper than human pilots when total training and infrastructure costs are taken into account, not to mention the risk of loss of their own personnel.

References

See also

List of missiles by country

External links