Technology
defines warfare. Air warfare was not even possible before the twentieth
century, save for the vulnerable and inefficient reconnaissance balloons that
were pioneered in Europe and America in the nineteenth century. In the
twenty-first century, air warfare ranges from strategic bombing to close air
support of ground troops to dog fights for air superiority to pilotless drones
that carry the eyes and ears, and sometimes the ordnance, of operators
hundreds, even thousands, of miles away. The U.S. boasts a missile defense
installation that can stop the unstoppable, an intercontinental ballistic
missile. Space-faring nations flirt with anti-satellite weapons launched from
earth and even the prospect of space-based weapons to fight one another and
threaten the earth below.
Ballistic missile
A
ballistic missile is a missile that follows a sub-orbital ballistic flight path
with the objective of delivering one or more warheads to a predetermined
target. To date, ballistic missiles have been propelled during powered flight
by chemical rocket engines of various types.
V-2:The first ballistic
missile was the A-4, commonly known as the V-2 rocket, developed by Nazi
Germany in the 1930s and 1940s under direction of Wernher von Braun. The first
successful launch of a V-2 was on October 3, 1942 and began operation on
September 6, 1944 against Paris, followed by an attack on London two days
later. By the end of World War II, May 1945, over 3,000 V-2s had been launched.
A
total of 30 nations have deployed operational ballistic missiles. Development
continues, with around 100 ballistic missile flight tests (not including those
of the US) in 2007, mostly by China, Iran and the Russian Federation. In 2010
the US and Russian governments signed a treaty to reduce their inventory of intercontinental
ballistic missiles (ICBMs) over a seven-year period (to 2017) to 1550 units
each.
A
ballistic missile trajectory consists of three parts: the powered flight
portion, the free-flight portion which constitutes most of the flight time, and
the re-entry phase where the Ballistic missiles can be launched from fixed
sites or mobile launchers, including vehicles (transporter erector launchers,
TELs), aircraft, ships and submarines.
Missiles can be propelled by either liquid-fueled or solid-fueled rocket
engines, solid fuel is preferred for military uses because it is less likely to
explode and can be kept ready-loaded for quick launch. Such engines commonly
propel tactical guided missiles—i.e., missiles intended for use within the
immediate battle area—toward their targets at twice the speed of sound.
Strategic missiles (weapons designed to strike targets far beyond the battle
area) are either of the cruise or ballistic type. Cruise missiles are
jet-propelled at subsonic speeds throughout their flights, while ballistic
missiles are rocket-powered only in the initial (boost) phase of flight, after
which they follow an arcing trajectory to the target. As gravity pulls the
ballistic warhead back to Earth, speeds of several times the speed of sound are
reached.
The
guidance system is the most important and sophisticated part of the missile. In
tactical missiles, electronic sensors locate the target by detecting energy
emitted or reflected from it. For example, heat-seeking missiles carry infrared
sensors that allow them to “home” onto the hot exhaust of jet engines. Anti
radiation missiles home onto radar emissions, while one type of optically
homing missile may “lock” onto an image of the target that is captured by a
television camera. Upon receiving information through its sensor, the guidance
system relays instructions for course correction to the control mechanism
through some type of autopilot contained within the missile or through commands
transmitted from the launch platform.
Ballistic
missiles contain some type of inertial guidance system, which compares the
missile’s actual speed and position to the positions that it must assume in
order to hit the target. The guidance system then generates correcting commands
to the control system. Inertial guidance has become so accurate that the United
States’ MX Peacekeeper ballistic missile, with a range of more than 6,000 miles
(more than 9,650 km), has a 50-percent chance of delivering its 10 nuclear
warheads within 400 feet (120 m) of their target.
Missile types:
Trident
II SLBM launched by ballistic missile submarine.
Ballistic
missiles can vary widely in range and use, and are often divided into
categories based on range. Various schemes are used by different countries to
categorize the ranges of ballistic missiles:
•
Tactical ballistic missile: Range between about 150 km and 300 km
•
Battlefield range ballistic missile (BRBM): Range less than 100 km
•
Theatre ballistic missile (TBM): Range between 300 km and 3,500 km
•
Short-range ballistic missile (SRBM): Range 1,000 km or less
•
Medium-range ballistic missile (MRBM): Range between 1,000 km and 3,500 km
•
Intermediate-range ballistic missile (IRBM) or long-range ballistic missile
(LRBM): Range between 3,500 km and 5,500 km
•
Intercontinental ballistic missile (ICBM): Range greater than 5500 km
•
Submarine-launched ballistic missile (SLBM): Launched from ballistic missile
submarines (SSBNs), all current designs have intercontinental range.
Intercontinental ballistic missile: A
Minuteman III ICBM test launch from Vandenberg Air Force Base, California,
United States.
ICBMs
are differentiated by having greater range and speed than other ballistic
missiles: intermediate-range ballistic missiles (IRBMs),medium-range ballistic
missiles (MRBMs), short-range ballistic missiles (SRBMs)—these shorter range
ballistic missiles are known collectively as theatre ballistic missiles. There
is no single, standardized definition of what ranges would be categorized as
intercontinental, intermediate, medium, or short. Additionally, ICBMs are
generally considered to be nuclear only; although several conceptual designs of
conventionally armed missiles have been considered, the launch of such a weapon
would be such a threat that it would demand a nuclear response, eliminating any
military value of such a weapon.
Modern ICBMs typically carry
multiple independently targetable reentry vehicles (MIRVs), each of which
carries a separate nuclear warhead, allowing a single missile to hit multiple
targets. MIRV was an outgrowth of the rapidly shrinking size and weight of
modern warheads and the Strategic Arms Limitation Treaties which imposed
limitations on the number of launch vehicles (SALT I and SALT II). It has also proved to be an
"easy answer" to proposed deployments of ABM systems—it is far less
expensive to add more warheads to an existing missile system than to build an
ABM system capable of shooting down the additional warheads; hence, most ABM
system proposals have been judged to be impractical. The first operational ABM
systems were deployed in the U.S. during 1970s. Safeguard ABM facility was
located in North Dakota and was operational from 1975–1976. The USSR deployed
its Galosh ABM system around Moscow in the 1970s, which remains in service.
Israel deployed a national ABM system based on the Arrow missile in 1998, but
it is mainly designed to intercept shorter-ranged theater ballistic missiles,
not ICBMs. The U.S. Alaska-based National missile defense system attained
initial operational capability in 2004.
External
and cross sectional views of a Trident II D5 nuclear missile system. It is a
submarine launched missile capable of carrying multiple nuclear warheads up to
8,000 km (5,000 mi). Trident missiles are carried by fourteen active US Navy
Ohio-class and four Royal Navy Vanguard-class submarines.
ICBMs can be deployed from TELs such as the
Russian Topol
•
one version of the RT-2UTTH Topol M which may be deployed from a self-propelled
mobile launcher, capable of moving through road less terrain, and launching a
missile from any point along its route.
Many
authorities say that missiles also release aluminized balloons, electronic
noisemakers, and other items intended to confuse interception devices and
radars.
One
particular weapon developed by the Soviet Union (FOBS) had a partial orbital
trajectory, and unlike most ICBMs its target could not be deduced from its
orbital flight path. It was decommissioned in compliance with arms control
agreements, which address the maximum range of ICBMs and prohibit orbital or
fractional-orbital weapons.
China.
India is known to be working on a SLBM system called the K-4 although there is
no hard evidence this will come into service in the near future.
In
1991, the United States and the Soviet Union agreed in the START I treaty to
reduce their deployed ICBMs and attributed warheads. As of 2009, all five of
the nations with permanent seats on the United Nations Security Council have
operational long-range ballistic missile systems: all except China have
operational submarine-launched missiles, and Russia, the United States and
China also have land-based ICBMs (the US' missiles are silo-based, China and
Russia have both silo and road-mobile missiles).
Israel
is believed to have deployed a road mobile nuclear ICBM, the Jericho III, which
entered service in 2008; an upgraded version is in development.
India
successfully test fired Agni V, with a strike range
of more than 5,000 km (3,100 mi), claiming entry into the ICBM club. It is
speculated by some intelligence agencies that North Korea is developing an
ICBM. North Korea successfully put a satellite into space on 12 December 2012
using the 32-metre-tall (105 ft) Unha-3 rocket. The United States claimed that
the launch was in fact a way to test an ICBM. (See Timeline of first orbital
launches by country). Most countries in the early stages of developing ICBMs
have used liquid propellants, with the known exceptions being the Indian
Agni-V, the planned South African RSA-4 ICBM and the now in service Israeli
Jericho 3.
No comments:
Post a Comment