Ballistic missiles

A ballistic missile is a type of missile that uses projectile motion to deliver warheads on a target. These weapons are guided only during relatively brief periods—most of the flight is unpowered. Short-range ballistic missiles stay within the Earth's atmosphere, while intercontinental ballistic missiles (ICBMs) are launched on a sub-orbital flight.

These weapons are in a distinct category from cruise missiles, which are aerodynamically guided in powered flight. Unlike cruise missiles, which are restricted to the atmosphere, it is advantageous for ballistic missiles to avoid the denser parts of the atmosphere and they may travel above the atmosphere into outer space.

History

The earliest form of ballistic missile 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 missile weapon called the Huolongchushui in naval battles against enemy ships.Needham, Volume 5, Part 7, 508-510. A modern pioneer ballistic missile was the A-4, commonly known as the V-2 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, more than 3,000 V-2s had been launched.

The R-7 Semyorka was the first intercontinental ballistic missile. In 2010, the U.S. and Russian governments signed a treaty to reduce their inventory of intercontinental ballistic missiles over a seven-year period (to 2017) to 1550 units each.

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.

Ballistic missiles can be launched from fixed sites or mobile launchers, including vehicles (e.g., transporter erector launchers), 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.

When the fuel is exhausted, no more thrust is provided and 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 .

The re-entry stage begins at an altitude where atmospheric drag plays a significant part in missile trajectory, and lasts until missile impact. Re-entry vehicles re-enter the Earth's atmosphere at very high velocities, on the order of at ICBM ranges.

Types

Ballistic missiles 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:

*Air-launched ballistic missile (ALBM)
*Tactical ballistic missile: Range between about
*Theatre ballistic missile (TBM): Range between
**Short-range ballistic missile (SRBM): Range between
**Medium-range ballistic missile (MRBM): Range between
*Intermediate-range ballistic missile (IRBM) or long-range ballistic missile (LRBM): Range between
*Intercontinental ballistic missile (ICBM): Range greater than
*Submarine-launched ballistic missile (SLBM): Launched from ballistic missile submarines (SSBNs)

Most current designs have intercontinental range with a notable exception of Indian operational SLBM Sagarika (missile), Sagarika and K-4 (SLBM), K-4 as well as North Korea's currently operationally deployed KN-11(2nd LD) N.K. leader calls SLBM launch success, boasts of nuke attack capacity
—Yonhap, 25 Aug 2016 08:17am which might not have intercontinental range. A comparable missile would be the decommissioned China's JL-1 SLBM with a range of less than 2,500 km.

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 prompt global strike, evaluating the idea of a conventionally armed ICBM for near-instant global air strike capability, despite the high costs).

Quasi-ballistic missiles

A quasi-ballistic missile (also called a semi-ballistic missile) is a category of missile that has a low trajectory and/or is largely ballistic but can perform maneuvers in flight or make unexpected changes in direction and range. They include anti-ship ballistic missiles. At a lower trajectory than a ballistic missile, a quasi-ballistic missile can maintain higher speed, thus allowing its target less time to react to the attack, at the cost of reduced range.

The Russian 9K720 Iskander, Iskander is a quasi-ballistic missile. The Russian Iskander-M cruises at hypersonic speed of 2,100–2,600 m/s (Mach 6–7) at a height of 50 km. The Iskander-M weighs 4,615 kg, carries a warhead of 710–800 kg, has a range of 480 km and achieves a Circular error probable, CEP of 5–7 meters. During flight it can maneuver at different altitudes and trajectories to evade anti-ballistic missiles.

List of quasi-ballistic missiles

;:
*DF-15 (active)
*DF-21D (active)
*DF-26 (active)
*B-611MR (active)
*SY-400 (active)
*XY-9
;:
*Hadès (missile), Hadès (retired)

;:
*Prithvi (missile), Prithvi-III (active)
*Dhanush (missile), Dhanush (active)
*Prahaar (missile), Prahaar (active)
*Shaurya (missile), Shaurya (active)
*Pralay (missile), Pralay (under development)

;
*Hyunmoo#Hyunmoo-1, Hyunmoo-1
*Hyunmoo#Hyunmoo-2, Hyunmoo-2A
**Hyunmoo-2B
**Hyunmoo-2C
*Hyunmoo#Hyunmoo-4, Hyunmoo-4

;
*Bora (missile), Bora (active)

;
*Fateh-110 (active)
*Qiam 1 (active)
*Khalij Fars (active)
*Kheibar Shekan (active)
*Sejjil (active)
*Shahab (missile), Shahab (active)
*Khorramshahr (missile) (active)
*Emad (missile) (active)
*Ghadr-110 (active)
*Zolfaghar (missile) (active)

;:
*EXTRA artillery rocket system, EXTRA (active)
*LORA (missile), LORA (active)
*Predator Hawk, Preadator Hawk (active)

;:
*KN-23 (under development)
*KN-24 (under development)

;:
*CM-400AKG (active)
*Nasr (missile), Nasr (active)
*Shaheen-III (active)

;\:
*R-27 Zyb#R-27K, R-27K (cancelled)
*OTR-21 Tochka, Tochka (active)
*R-400 Oka, Oka (retired)
*Iskander (missile), Iskander (active)

;:
*MGM-140 ATACMS, MGM-140B/E ATACMS (active)

Hypersonic ballistic missile

Many ballistic missiles reach hypersonic speeds (i.e. Speed of sound, Mach 5 and above) when they re-enter the atmosphere from space. However, in common military terminology, the term "hypersonic ballistic missile" is generally only given to those that can be maneuvered before hitting their target and don’t follow a simple ballistic trajectory.

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 Booster (rocketry), rocket booster and launch fuel. Throw-weight may refer to any type of warhead, but in normal modern usage, it refers almost exclusively to fission bomb, nuclear or thermonuclear weapon, thermonuclear payloads. It was once also a consideration in the design of naval ships and the number and size of their guns.

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. 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.

The missiles with the world's heaviest payloads are the Russian SS-18 and Chinese DF-5, CSS-4 and , Russia was developing a new heavy-lift, liquid-propellant ICBM called the RS-28 Sarmat, Sarmat.

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 (physics), impulse of the missile. By reducing the payload weight, different trajectories can be selected, which can either increase the nominal range or decrease the total time in flight.

A depressed trajectory is 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. 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.

Combat use

The following ballistic missiles have been used in combat:

* 9K720 Iskander
* Ababil-100
* Al-Samoud 2
* Dongfeng (missile)#Dongfeng 12 (CSS-X-15), DF-12
* Fateh-110
* LORA (missile), LORA
* MGM-140 ATACMS
* OTR-21 Tochka
* Qaher-1/2M
* Scud missile, Scud types
* V-2
* Zolfaghar (missile), Zolfaghar

See also

*Ballistic missile flight phases
*Missile (guided)
*Multiple independently targetable reentry vehicle, MIRV
*NATO reporting name (has lists of various Soviet missiles)
*Surface-to-surface missile
*Weapons of mass destruction
*List of currently active missiles of the United States military
*List of ICBMs
*List of missiles
*List of missiles by nation
*List of NATO reporting names for ballistic missile submarines

Notes

References

*Needham, Joseph (1986). ''Science and Civilization in China: Volume 5, Chemistry and Chemical Technology, Part 7, Military Technology; the Gunpowder Epic''. Taipei: Caves Books.

Further reading

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External links

Missile Threat
A Project of the Center for Strategic and International Studies

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Ballistic missiles,
Chinese inventions
German inventions of the Nazi period
Wernher von Braun