Ballistic missile

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Minuteman-III MIRV launch sequence :
1. The missile launches out of its silo by firing its 1st-stage boost motor (A).
2. About 60 seconds after launch, the 1st-stage drops off and the 2nd-stage motor (B) ignites. The missile shroud (E) is ejected.
3. About 120 seconds after launch, the 3rd-stage motor (C) ignites and separates from the 2nd stage.
4. About 180 seconds after launch, 3rd-stage thrust terminates and the Post-Boost Vehicle (D) separates from the rocket.
5. The Post-Boost Vehicle maneuvers itself and prepares for re-entry vehicle (RV) deployment.
6. The RVs, as well as decoys and chaff, are deployed.
7. The RVs (now armed) and chaff re-enter the atmosphere at high speeds.
8. The nuclear warheads detonate. Minuteman III MIRV path.svg
Minuteman-III MIRV launch sequence :
1. The missile launches out of its silo by firing its 1st-stage boost motor (A).
2. About 60 seconds after launch, the 1st-stage drops off and the 2nd-stage motor (B) ignites. The missile shroud (E) is ejected.
3. About 120 seconds after launch, the 3rd-stage motor (C) ignites and separates from the 2nd stage.
4. About 180 seconds after launch, 3rd-stage thrust terminates and the Post-Boost Vehicle (D) separates from the rocket.
5. The Post-Boost Vehicle maneuvers itself and prepares for re-entry vehicle (RV) deployment.
6. The RVs, as well as decoys and chaff, are deployed.
7. The RVs (now armed) and chaff re-enter the atmosphere at high speeds.
8. The nuclear warheads detonate.

A ballistic missile follows a ballistic trajectory to deliver one or more warheads on a predetermined target. These weapons are only guided during relatively brief periods of flight—most of their trajectory is unpowered, being governed by gravity and air resistance if in the atmosphere. Shorter range ballistic missiles stay within the Earth's atmosphere, while longer-ranged intercontinental ballistic missiles (ICBMs), are launched on a sub-orbital flight trajectory and spend most of their flight out of the atmosphere.

Warhead damage-creating payload delivered by a rocket, missile, or torpedo

A warhead is the explosive or toxic material that is delivered by a missile, rocket, or torpedo. It is a type of bomb.

Atmosphere of Earth Layer of gases surrounding the planet Earth

The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention, and reducing temperature extremes between day and night.

Intercontinental ballistic missile Ballistic missile with a range of more than 5,500 kilometres

An intercontinental ballistic missile (ICBM) is a guided ballistic missile with a minimum range of 5,500 kilometres (3,400 mi) primarily designed for nuclear weapons delivery. Similarly, conventional, chemical, and biological weapons can also be delivered with varying effectiveness, but have never been deployed on ICBMs. Most modern designs support multiple independently targetable reentry vehicles (MIRVs), allowing a single missile to carry several warheads, each of which can strike a different target. Russia, the United States, India, North Korea, and China are the only countries that have operational ICBMs.

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These weapons are in a distinct category from cruise missiles, which are aerodynamically guided in powered flight.

Cruise missile Aerodynamic missile

A cruise missile is a guided missile used against terrestrial targets, that remains in the atmosphere and flies the major portion of its flight path at approximately constant speed. Cruise missiles are designed to deliver a large warhead over long distances with high precision. Modern cruise missiles are capable of travelling at supersonic or high subsonic speeds, are self-navigating, and are able to fly on a non-ballistic, extremely low-altitude trajectory.

Lift (force) force; aerodynamics term

A fluid flowing past the surface of a body exerts a force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the force parallel to the flow direction. Lift conventionally acts in an upward direction in order to counter the force of gravity, but it can act in any direction at right angles to the flow.

History

Replica of V-2 Fusee V2.jpg
Replica of V-2

The earliest form of ballistic missiles dates from the 13th century with its use derived from the history of rockets. In the 14th century, the Ming Chinese navy used an early form of a ballistic cruise missile weapon called the Huo long chu shui in naval battles against enemy ships. [1] A modern pioneer ballistic missile was the A-4, [2] commonly known as the V-2 rocket developed by Nazi Germany in the 1930s and 1940s under the direction of Wernher von Braun. The first successful launch of a V-2 was on October 3, 1942, and it began operation on September 6, 1944 against Paris, followed by an attack on London two days later. By the end of World War II in Europe in May 1945, over 3,000 V-2s had been launched. [3]

History of rockets

The first rockets were used as propulsion systems for arrows, and may have appeared as early as the 10th century in Song dynasty China. However more solid documentary evidence does not appear until the 13th century. The technology probably spread across Eurasia in the wake of the Mongol invasions of the mid-13th century. Usage of rockets as weapons before modern rocketry is attested in China, Korea, Europe, Middle East, Mongolia and Indian subcontinent. One of the first recorded rocket launchers is the "wasp nest" fire arrow launcher produced by the Ming dynasty in 1380. In Europe rockets were also used in the same year at the Battle of Chioggia. The Joseon kingdom of Korea used a type of mobile multiple rocket launcher known as the "Munjong Hwacha" by 1451. Iron-cased rockets, known as Mysorean rockets, were developed in Kingdom of Mysore by the mid 18th century by Hyder Ali and Tipu Sultan, the rockets may be inspired by the Chinese and Mongolian rockets which existed much earlier as no such recorded use of rockets exist anywhere else in the Indian subcontinent prior to that of Mysorean rockets, and were later copied by the British. The later models and improvements were known as the Congreve rocket and used in the Napoleonic Wars.

Huolongchushui or fire dragon issuing from the water were the earliest form of multistage rockets and ballistic cruise missiles used in medieval China. The name of the weapon was used to strike fear into enemy troops. If the enemy was out of range, the fire dragon had a contingency: a magazine of three rocket driven arrows located within the mouth of the missile. It acted as one of the world's earliest multistage rockets and ballistic cruise missiles, fired at enemy ships in naval battles.

V-2 rocket Worlds first short-range guided ballistic missile

The V-2, technical name Aggregat 4 (A4), was the world's first long-range guided ballistic missile. The missile, powered by a liquid-propellant rocket engine, was developed during the Second World War in Germany as a "vengeance weapon", assigned to attack Allied cities as retaliation for the Allied bombings against German cities. The V-2 rocket also became the first man-made object to travel into space by crossing the Kármán line with the vertical launch of MW 18014 on 20 June 1944.

The R-7 Semyorka was the first intercontinental ballistic missile.

R-7 Semyorka Intercontinental ballistic missile

The R-7 was a Soviet missile developed during the Cold War, and the world's first intercontinental ballistic missile. The R-7 made 28 launches between 1957 and 1961, but was never deployed operationally. A derivative, the R-7A, was deployed from 1959 to 1968. To the West it was known by the NATO reporting name SS-6 Sapwood and within the Soviet Union by the GRAU index 8K71. In modified form, it launched Sputnik 1, the first artificial satellite, into orbit, and became the basis for the R-7 family which includes Sputnik, Luna, Molniya, Vostok, and Voskhod space launchers, as well as later Soyuz variants.

A total of 30 nations have deployed operational ballistic missiles. Development continues with around 100 ballistic missile flight tests in 2007 (not including those of the US), mostly by China, Iran, and the Russian Federation.[ citation needed ] In 2010, the U.S. 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. [4]

Side view of Minuteman-III ICBM Minuteman III diagram.png
Side view of Minuteman-III ICBM

Flight

An intercontinental 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 missile re-enters the Earth's atmosphere. (The flight phases for shorter-range ballistic missiles are essentially the first two phases of the ICBM, as some ballistic categories do not leave the atmosphere.)[ citation needed ]

Ballistic missiles can be launched from fixed sites or mobile launchers, including vehicles (e.g., transporter erector launchers (TELs)), aircraft, ships, and submarines. The powered flight portion can last from a few tenths of seconds to several minutes and can consist of multiple rocket stages.[ citation needed ]

When in space no more thrust is provided, the missile enters free-flight. In order to cover large distances, ballistic missiles are usually launched into a high sub-orbital spaceflight; for intercontinental missiles, the highest altitude (apogee) reached during free-flight is about 2,000 kilometers (1,200 mi). [5]

The re-entry stage begins at an altitude where atmospheric drag plays a significant part in missile trajectory, and lasts until missile impact.[ citation needed ]

Reentry vehicles reenter the Earth's atmosphere at very high velocities, on the order of 6–8 kilometers per second (22,000–29,000 km/h; 13,000–18,000 mph) at ICBM ranges. [6]

Advantages

The course taken by ballistic missiles has two significant desirable properties. First, ballistic missiles that fly above the atmosphere have a much longer range than would be possible for cruise missiles of the same size. Powered rocket flight through thousands of kilometers of air would require vastly greater amounts of fuel, making the launch vehicles larger and easier to detect and intercept. Powered missiles that can cover similar ranges, such as cruise missiles, do not use rocket motors for the majority of their flight, but instead use more economical jet engines. However, cruise missiles have not made ballistic missiles obsolete, due to the second major advantage: ballistic missiles can travel extremely quickly along their flight path. An ICBM can strike a target within a 10,000 km range in about 30 to 35 minutes.[ citation needed ] With terminal speeds of over 5,000 m/s, ballistic missiles are much harder to intercept than cruise missiles, due to the much shorter time available. Therefore, ballistic missiles are some of the most feared weapons available, despite the fact that cruise missiles are cheaper, more mobile, and more versatile.[ citation needed ]

Missile types

Trident II SLBM launched by ballistic missile submarine. Trident II missile image.jpg
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, short- and medium-range missiles are often collectively referred to as tactical and theatre ballistic missiles, respectively. Long- and medium-range ballistic missiles are generally designed to deliver nuclear weapons because their payload is too limited for conventional explosives to be cost-effective in comparison to conventional bomber aircraft (though the U.S. is evaluating the idea of a conventionally armed ICBM for near-instant global air strike capability, despite the high costs).

Throw-weight

Throw-weight is a measure of the effective weight of ballistic missile payloads. It is measured in kilograms or tonnes. Throw-weight equals the total weight of a missile's warheads, reentry vehicles, self-contained dispensing mechanisms, penetration aids, and missile guidance systems: generally all components except for the launch rocket booster and launch fuel. Throw-weight may refer to any type of warhead, but in normal modern usage, it almost refers to almost exclusively nuclear or thermonuclear payloads. It was once also a consideration in the design of naval ships and the number/size of guns that they carried.

Throw-weight was used as a criterion in classifying different types of missiles during Strategic Arms Limitation Talks between the Soviet Union and the United States. [8] The term became politically controversial during debates over the arms control accord, as critics of the treaty alleged that Soviet missiles were able to carry larger payloads and so enabled the Soviets to maintain higher throw-weight than an American force with a roughly comparable number of lower-payload missiles. [9]

The missiles with the world's heaviest payloads are the Russian SS-18 and Chinese CSS-4 and Russia is developing a new heavy-lift, liquid-propellant ICBM called the Sarmat. [6]

Depressed trajectory

Throw-weight is normally calculated using an optimal ballistic trajectory from one point on the surface of the Earth to another. An optimal trajectory maximizes the total payload (throw-weight) using the available impulse of the missile. By reducing the payload weight, different trajectories can be selected, which can either the nominal range or decrease the total time in flight.

A depressed trajectory is a non-optimal, as a lower and flatter trajectory takes less time between launch and impact but has a lower throw-weight. The primary reasons to choose a depressed trajectory are to evade anti-ballistic missile systems by reducing the time available to shoot down the attacking vehicle (especially during the vulnerable burn-phase against space-based ABM systems) or a nuclear first-strike scenario. [10] An alternate, non-military, purpose for a depressed trajectory is in conjunction with the space plane concept with use of air-breathing engines, which requires the ballistic missile to remain low enough inside the atmosphere for air-breathing engines to function.

See also

Notes

  1. Needham, Volume 5, Part 7, 508-510.
  2. Zaloga, Steven (2003). V-2 Ballistic Missile 1942–52 . Reading: Osprey Publishing. p. 3. ISBN   978-1-84176-541-9.
  3. Clayton K. S. Chun (2006). Thunder Over the Horizon: From V-2 Rockets to Ballistic Missiles. Greenwood Publishing Group. p. 54.
  4. U.S. Department of State (8 April 2010). "Treaty between the United States of America and the Russian Federation on Measures for the Further Reduction and Limitation of Strategic Offensive Arms". Retrieved 25 November 2018.
  5. Almasy, Steve; Kwon, K. J.; Lee, Taehoon (14 May 2017). "North Korea launches missile". CNN . Retrieved 2017-10-14.
  6. 1 2 "Ballistic and Cruise Missile Threat". Defense Intelligence Ballistic Missile Analysis Committee. June 2017.
  7. (2nd LD) N.K. leader calls SLBM launch success, boasts of nuke attack capacity - Yonhap, 25 Aug 2016 08:17am
  8. James John Tritten, Throw-Weight and Arms Control, Air University Review, Nov-Dec 1982.
  9. New York Times, What Is Throw-Weight?, July 15, 1991.
  10. Science & Global Security, 1992, Volume 3, pp.101-159 Depressed Trajectory SLBMs: A Technical Evaluation and Arms Control Possibilities

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