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 kilometers 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 to avoid
radar detection.
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.
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 it the nickname of "buzz bomb". 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.
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.
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.
General design
Cruise missiles generally consist of a guidance system, payload, and propulsion system, housed in an airframe with small wings and
empennage for flight control. Payloads usually consist of a conventional warhead or a
nuclear warhead. Cruise missiles tend to be propelled by a
jet engine,
turbofan engines being preferred due to their greater efficiency at low altitude and sub-sonic speed.
Guidance systems
Guidance systems also vary greatly. Low-cost systems use a
radar altimeter, barometric altimeter and
clock to navigate a
digital strip
map. More advanced systems use
inertial guidance,
satellite navigation and
terrain contour matching (TERCOM). Use of an
automatic target recognition (ATR) algorithm/device in the guidance system increases accuracy of the missile. 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:
- 3M-54 Klub (Russia) supersonic terminal stage only
- C-803 (China) supersonic terminal stage only
Long-range subsonic
Both the U.S. and the U.S.S.R. developed several long-range subsonic cruise missiles. These missiles have a range of over and fly at about . They typically have a launch weight of about 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. 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 BGM-109) and ALCM (AGM-86) were competing designs for the U.S.A.F. 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.A.F 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.S.R.
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
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.
Pakistan also have
Babur cruise missile and
Ra'ad ALCM with nuclear warhead
Efficiency in modern warfare
Currently 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 personnel.
This all may change rapidly with the development of low cost miniature cruise missiles.
See also
