You may ask your self what
missile ARE?
In a modern
military, a
missile is a self-propelled
guided weapon
system. Missiles have four system components: targeting and/or
guidance, flight system, engine, and warhead. Missiles come in types
adapted for different purposes:
surface-to-surface and
air-to-surface missiles (ballistic, cruise, anti-ship, anti-tank),
surface-to-air missiles (anti-aircraft and anti-ballistic),
air-to-air missiles, and
anti-satellite missiles.
An ordinary English-language usage predating guided weapons is simply
any thrown object, such as items thrown at players by rowdy spectators
at a sporting event.
Etymology and usage
The word
missile comes from the
Latin verb
mittere, meaning "to send".
In military usage, munitions projected towards a target are broadly categorised as follows:
- A powered, guided munition that travels through the air or space is known as a missile (or guided missile.)
- A powered, unguided munition is known as a rocket.
- Unpowered munitions not fired from a gun are called bombs whether guided or not; unpowered, guided munitions are known as guided bombs or "smart bombs".
- Munitions that are fired from a gun are known as projectiles whether guided or not. If explosive they are known more specifically as shells or mortar bombs.
- Powered munitions that travel through water are called torpedoes (an older usage includes fixed torpedoes, which might today be called mines).
- Hand grenades are not usually classed as missiles.
A common further sub-division is to consider
ballistic missile to mean a munition that follows a
ballistic trajectory and
cruise missile to describe a munition that generates lift.
Early development
The first missiles to be used operationally were a series of
missiles developed by
Nazi Germany in
World War II. Most famous of these are the
V-1 flying bomb and
V-2, both of which used a simple mechanical
autopilot
to keep the missile flying along a pre-chosen route. Less well known
were a series of anti-shipping and anti-aircraft missiles, typically
based on a simple
radio control system directed by the operator. However, these early systems in World War II were only built in small numbers.
Technology
Guided missiles have a number of different system components:
Guidance systems
Missiles may be targeted in a number of ways. The most common method is to use some form of
radiation, such as
infrared,
lasers or
radio waves,
to guide the missile onto its target. This radiation may emanate from
the target (such as the heat of an engine or the radio waves from an
enemy radar), it may be provided by the missile itself (such as a radar)
or it may be provided by a friendly third party (such as the radar of
the launch vehicle/platform, or a laser designator operated by friendly
infantry). The first two are often known as
fire-and-forget as they need no further support or control from the launch vehicle/platform in order to function. Another method is to use a
TV camera—using either
visible light
or infra-red—in order to see the target. The picture may be used either
by a human operator who steers the missile onto its target, or by a
computer doing much the same job. One of the more bizarre guidance
methods instead used a
pigeon to steer the missile to its target.
Many missiles use a combination of two or more of the above methods,
to improve accuracy and the chances of a successful engagement.
Targeting systems
Another method is to target the missile by knowing the location of the target, and using a guidance system such as
INS,
TERCOM or
GPS.
This guidance system guides the missile by knowing the missile's
current position and the position of the target, and then calculating a
course between them. This job can also be performed somewhat crudely by a
human operator who can see the target and the missile, and guides it
using either cable or
radio based remote-control, or by an
automatic system that can simultaneously track the target and the missile.
Flight system
Whether a guided missile uses a targeting system, a guidance system
or both, it needs a flight system. The flight system uses the data from
the targeting or guidance system to maneuver the missile in flight,
allowing it to counter inaccuracies in the missile or to follow a moving
target. There are two main systems: vectored thrust (for missiles that
are powered throughout the guidance phase of their flight) and
aerodynamic maneuvering (wings, fins, canards, etc.).
Engine
Missiles are powered by an engine, generally either a type of rocket or jet engine. Rockets are generally of the
solid fuel type for ease of maintenance and fast deployment, although some larger ballistic missiles use
liquid fuel rockets. Jet engines are generally used in
cruise missiles, most commonly of the
turbojet type, due to its relative simplicity and low frontal area.
Turbofans and
ramjets
are the only other common forms of jet engine propulsion, although any
type of engine could theoretically be used. Missiles often have multiple
engine stages, particularly in those launched from the surface. These
stages may all be of similar types or may include a mix of engine types -
for example, surface-launched cruise missiles often have a rocket
booster for launching and a jet engine for sustained flight.
Some missiles may have additional propulsion from another source at launch; for example the
V1 was launched by a catapult and the
MGM-51 was fired out of a tank gun (using a smaller charge than would be used for a shell).
Warhead
Missiles generally have one or more
explosive warheads,
although other weapon types may also be used. The warhead or warheads
of a missile provides its primary destructive power (many missiles have
extensive secondary destructive power due to the high kinetic energy of
the weapon and unburnt fuel that may be on board). Warheads are most
commonly of the
high explosive type, often employing
shaped charges to exploit the accuracy of a guided weapon to destroy hardened targets. Other warhead types include
submunitions,
incendiaries,
nuclear weapons,
chemical,
biological or
radiological weapons or
kinetic energy penetrators. Warheadless missiles are often used for testing and training purposes.
Basic roles
Missiles are generally categorized by their launch platform and
intended target. In broadest terms, these will either be surface (ground
or water) or air, and then sub-categorized by range and the exact
target type (such as anti-tank or anti-ship). Many weapons are designed
to be launched from both surface or the air, and a few are designed to
attack either surface or air targets (such as the
ADATS missile). Most weapons require some modification in order to be launched from the air or surface, such as adding
boosters to the surface-launched version.
Surface-to-Surface/Air-to-Surface
Ballistic
After the boost-stage, ballistic missiles follow a
trajectory mainly determined by
ballistics. The guidance is for relatively small deviations from that.
Ballistic missiles are largely used for land attack missions.
Although normally associated with nuclear weapons, some conventionally
armed ballistic missiles are in service, such as
ATACMS.
The V2 had demonstrated that a ballistic missile could deliver a
warhead to a target city with no possibility of interception, and the
introduction of
nuclear weapons
meant it could efficiently do damage when it arrived. The accuracy of
these systems was fairly poor, but post-war development by most military
forces improved the basic
inertial platform concept to the point where it could be used as the guidance system on
ICBMs flying thousands of kilometers. Today the ballistic missile represents the only
strategic deterrent in most military forces, however some ballistic missiles are being adapted for conventional roles, such as the Russian
Iskander or the Chinese
DF-21D anti-ship ballistic missile. Ballistic missiles are primarily surface launched from
mobile launchers,
silos,
ships or
submarines, with
air launch being theoretically possible with a weapon such as the cancelled
Skybolt missile.
The
Russian Topol M (SS-27 Sickle B) is the fastest (7,320 m/sec) missile currently in service
[2]
Cruise missile
Main article:
Cruise missile
The
V1 had been successfully intercepted during
World War II, but this did not make the
cruise missile
concept entirely useless. After the war, the US deployed a small number
of nuclear-armed cruise missiles in Germany, but these were considered
to be of limited usefulness. Continued research into much longer ranged
and faster versions led to the US's
Navaho missile, and its
Soviet counterparts, the
Burya and
Buran cruise missile. However, these were rendered largely obsolete by the
ICBM,
and none were used operationally. Shorter-range developments have
become widely used as highly accurate attack systems, such as the US
Tomahawk missile, the Russian
Kh-55 the German
Taurus missile and the Pakistani
Babur cruise missile.The
BrahMos cruise missile which is a joint venture between India and Russia.
Cruise missiles are generally associated with land attack operations,
but also have an important role as anti-shipping weapons. They are
primarily launched from air, sea or submarine platforms in both roles,
although land based launchers also exist.
Anti-ship
Another major German missile development project was the anti-shipping class (such as the
Fritz X and
Henschel Hs 293),
intended to stop any attempt at a cross-channel invasion. However the
British were able to render their systems useless by jamming their
radios, and missiles with
wire guidance were not ready by
D-Day.
After the war the anti-shipping class slowly developed, and became a
major class in the 1960s with the introduction of the low-flying jet- or
rocket-powered cruise missiles known as "sea-skimmers". These became
famous during the
Falklands War when an Argentine
Exocet missile sank a
Royal Navy destroyer.
A number of anti-submarine missiles also exist; these generally use
the missile in order to deliver another weapon system such as a
torpedo or
depth charge to the location of the submarine, at which point the other weapon will conduct the underwater phase of the mission.
Anti-tank
By the end of WWII all forces had widely introduced unguided rockets using
HEAT warheads as their major anti-tank weapon (see
Panzerfaust,
Bazooka).
However these had a limited useful range of a 100 m or so, and the
Germans were looking to extend this with the use of a missile using
wire guidance,
the X-7. After the war this became a major design class in the later
1950s, and by the 1960s had developed into practically the only non-tank
anti-tank system in general use. During the 1973
Yom Kippur War between Israel and Egypt, the
9M14 Malyutka
(aka "Sagger") man-portable anti-tank missile proved potent against
Israeli tanks. While other guidance systems have been tried, the basic
reliability of wire-guidance means this will remain the primary means of
controlling anti-tank missile in the near future. Anti tank missiles
may be launched from aircraft, vehicles or by ground troops in the case
of smaller weapons.
Surface-to-air
Anti-aircraft
By 1944 US and British air forces were sending huge air fleets over occupied Europe, increasing the pressure on the
Luftwaffe
day and night fighter forces. The Germans were keen to get some sort of
useful ground-based anti-aircraft system into operation. Several
systems were under development, but none had reached operational status
before the war's end. The
US Navy also started missile research to deal with the
Kamikaze threat. By 1950 systems based on this early research started to reach operational service, including the
US Army's
Nike Ajax, the Navy's "3T's" (Talos, Terrier, Tartar), and soon followed by the Soviet
S-25 Berkut and
S-75 Dvina
and French and British systems. Anti-aircraft weapons exist for
virtually every possible launch platform, with surface-launched systems
ranging from huge, self-propelled or ship-mounted launchers to man
portable systems.
Anti-ballistic
Like most missiles, the
Arrow missile,
S-300,
S-400,
Advanced Air Defence and
MIM-104 Patriot are for defense against short-range missiles and carry explosive warheads.
However, in the case of a large closing speed,
a projectile without explosives is used, just a
collision is sufficient to destroy the target. See
Missile Defense Agency for the following systems being developed:
Air-to-air
Soviet
RS-82 rockets were successfully tested in combat at the
Battle of Khalkhin Gol in 1939.
German experience in World War II demonstrated that destroying a
large aircraft was quite difficult, and they had invested considerable
effort into
air-to-air missile systems to do this. Their
Me-262's
jets often carried R4M rockets, and other types of "bomber destroyer"
aircraft had unguided rockets as well. In the post-war period the R4M
served as the pattern for a number of similar
systems,
used by almost all interceptor aircraft during the 1940s and '50s.
Lacking guidance systems, such rockets had to be carefully aimed at
relatively close range to successfully hit the target. The
US Navy and
U.S. Air Force began deploying guided missiles in the early 1950s, most famous being the US Navy's
AIM-9 Sidewinder and USAF's
AIM-4 Falcon. These systems have continued to advance, and modern air warfare consists almost entirely of missile firing. In the
Falklands War, less powerful British
Harriers
were able to defeat faster Argentinian opponents using AIM-9G missiles
provided by the United States as the conflict began. The latest
heat-seeking designs can lock onto a target from various angles, not
just from behind, where the heat signature from the engines is
strongest. Other types rely on radar guidance (either on-board or
"painted" by the launching aircraft). Air to Air missiles also have a
wide range of sizes, ranging from helicopter launched self-defense
weapons with a range of a few kilometers, to long range weapons designed
for interceptor aircraft such as the
Vympel R-37.
Anti-satellite
In the 1950s and 1960s, Soviet designers started work on an anti-satellite weapon, called the "
Istrebitel Sputnik",
which meant literally, interceptor of satellites, or destroyer of
satellites. After a lengthy development process of roughly 20 years, it
was finally decided that testing of the Istrebitel Sputnik be canceled.
This was when the U.S. started testing their own systems. The
Brilliant Pebbles
defense system proposed during the 1980s would have used kinetic energy
collisions without explosives. Anti satellite weapons may be launched
either by an aircraft or a surface platform, depending on the design. To
date, only a few known tests have occurred.
