Kinetic energy weapon

Last updated
The Homing Overlay Experiment used a metal fan that was rolled up during launch and expanded during flight. The metal has five times as much destructive power as an explosive warhead of the same weight. SO4 Hoe open Web.jpg
The Homing Overlay Experiment used a metal fan that was rolled up during launch and expanded during flight. The metal has five times as much destructive power as an explosive warhead of the same weight.

A kinetic energy weapon (also known as kinetic weapon, kinetic energy warhead, kinetic warhead, kinetic projectile, kinetic kill vehicle) is a projectile weapon based solely on a projectile's kinetic energy to inflict damage to a target, instead of using any explosive, incendiary/thermal, chemical or radiological payload. All kinetic weapons work by attaining a high flight speed — generally supersonic or even up to hypervelocity — and collide with their targets, converting its kinetic energy and relative impulse into destructive shock waves, heat and cavitation. In kinetic weapons with unpowered flight, the muzzle velocity or launch velocity often determines the effective range and potential damage of the kinetic projectile.

Contents

Kinetic weapons are the oldest and most common ranged weapons used in human history, with the projectiles varying from blunt projectiles such as rocks and round shots, pointed missiles such as arrows, bolts, darts, and javelins, to modern tapered high-velocity impactors such as bullets, flechettes, and penetrators. Typical kinetic weapons accelerate their projectiles mechanically (by muscle power, mechanical advantage devices, elastic energy or pneumatics) or chemically (by propellant combustion, as with firearms), but newer technologies are enabling the development of potential weapons using electromagnetically launched projectiles, such as railguns, coilguns and mass drivers. There are also concept weapons that are accelerated by gravity, as in the case of kinetic bombardment weapons designed for space warfare.

The term hit-to-kill, or kinetic kill, is also used in the military aerospace field to describe kinetic energy weapons accelerated by a rocket engine. It has been used primarily in the anti-ballistic missile (ABM) and anti-satellite weapon (ASAT) fields, but some modern anti-aircraft missiles are also kinetic kill vehicles. Hit-to-kill systems are part of the wider class of kinetic projectiles, a class that has widespread use in the anti-tank field.

Basic concept

Kinetic energy is a function of mass and the velocity of an object. [1] For a kinetic energy weapon in the aerospace field, both objects are moving and it is the relative velocity that is important. [lower-alpha 1] In the case of the interception of a reentry vehicle (RV) from an intercontinental ballistic missile (ICBM) during the terminal phase of the approach, the RV will be traveling at approximately 15,000 miles per hour (24,000 km/h) while the interceptor will be on the order of 7,000 miles per hour (11,000 km/h). Because the interceptor may not be approaching head-on, a lower bound on the relative velocity on the order of 16,000 miles per hour (26,000 km/h) can be assumed, [2] or converting to SI units, approximately 7150 meters per second.

At that speed, every kilogram of the interceptor will have an energy of:

TNT has an explosive energy of about 4853 joules per gram, [3] or about 5 MJ per kilogram. That means the impact energy of the mass of the interceptor is over five times that of a detonating warhead of the same mass. [2]

It may seem like this makes a warhead superfluous, but a hit-to-kill system has to actually hit the target, which may be on the order of half a meter wide, while a conventional warhead releases numerous small fragments that increase the possibility of impact over a much larger area, albeit with a much smaller impact mass. This has led to alternative concepts that attempt to spread out the potential impact zone without explosives. [2] The SPAD concept of the 1960s used a metal net with small steel balls that would be released from the interceptor missile, [4] while the Homing Overlay Experiment of the 1980s used a fan-like metal disk. [5]

As the accuracy and speed of modern surface-to-air missiles (SAMs) improved, and their targets began to include theatre ballistic missiles (TBMs), many existing systems have moved to hit-to-kill attacks as well. This includes the MIM-104 Patriot, whose PAC-3 version removed the warhead and upgraded the solid fuel rocket motor to produce an interceptor missile that is much smaller overall, [6] as well as the RIM-161 Standard Missile 3, which is dedicated to the anti-missile role. [7]

Delivery

Some kinetic weapons for targeting objects in spaceflight are anti-satellite weapons and anti-ballistic missiles. Since in order to reach an object in orbit it is necessary to attain an extremely high velocity, their released kinetic energy alone is enough to destroy their target; explosives are not necessary. For example: the energy of TNT is 4.6 MJ/kg, and the energy of a kinetic kill vehicle with a closing speed of 10 km/s (22,000 mph) is 50 MJ/kg. For comparison, 50 MJ is equivalent to the kinetic energy of a school bus weighing 5 metric tons, traveling at 509 km/h (316 mph; 141 m/s). This saves costly weight and there is no detonation to be precisely timed. This method, however, requires direct contact with the target, which requires a more accurate trajectory. Some hit-to-kill warheads are additionally equipped with an explosive directional warhead to enhance the kill probability (e.g. Israeli Arrow missile or U.S. Patriot PAC-3).

With regard to anti-missile weapons, the Arrow missile and MIM-104 Patriot PAC-2 have explosives, while the Kinetic Energy Interceptor (KEI), Lightweight Exo-Atmospheric Projectile (LEAP, used in Aegis BMDS), and THAAD do not (see Missile Defense Agency).

A kinetic projectile can also be dropped from aircraft. This is applied by replacing the explosives of a regular bomb with a non-explosive material (e.g. concrete), for a precision hit with less collateral damage; these are called concrete bombs. A typical bomb has a mass of 900 kg (2,000 lb) and a speed of impact of 800 km/h (500 mph). It is also applied for training the act of dropping a bomb with explosives. This method has been used in Operation Iraqi Freedom and the subsequent military operations in Iraq by mating concrete-filled training bombs with JDAM GPS guidance kits, to attack vehicles and other relatively "soft" targets located too close to civilian structures for the use of conventional high explosive bombs.

Advantages and disadvantages

The primary advantage kinetic energy weapons is that they minimize the launch mass of the weapon, as no weight has to be set aside for a separate warhead. Every part of the weapon, including the airframe, electronics and even the unburned maneuvering fuel contributes to the destruction of the target. Lowering the total mass of the vehicle offers advantages in terms of the required launch vehicle needed to reach the required performance, and also reduces the mass that needs to be accelerated during maneuvering. [2]

Another advantage of kinetic energy weapons is that any impact will almost certainly guarantee the destruction of the target. In contrast, a weapon using a blast fragmentation warhead will produce a large cloud of small fragments that will not cause as much destruction on impact. Both will produce effects that can easily be seen at long distance using radar or infrared detectors, but such a signal will generally indicate complete destruction in the case of a kinetic energy weapons while the fragmentation case does not guarantee a "kill". [2]

No chemical munitions in the weapons also means that there is far less pollution of an area from a kinetic weapon.

The main disadvantage of the kinetic energy weapons is that they require extremely high accuracy in the guidance system, on the order of 0.5 metres (2 ft). [2]

See also

Explanatory notes

  1. As opposed to the anti-tank field, where the velocity of the tank can be approximated as zero compared to that of the weapon.

Related Research Articles

<span class="mw-page-title-main">Anti-ballistic missile</span> Surface-to-air missile designed to counter ballistic missiles

An anti-ballistic missile (ABM) is a surface-to-air missile designed to counter ballistic missiles. Ballistic missiles are used to deliver nuclear, chemical, biological, or conventional warheads in a ballistic flight trajectory. The term "anti-ballistic missile" is a generic term for a system designed to intercept and destroy any type of ballistic threat; however, it is commonly used for systems specifically designed to counter intercontinental ballistic missiles (ICBMs).

<span class="mw-page-title-main">Missile</span> Self-propelled guided weapon system

A missile is an airborne ranged weapon capable of self-propelled flight aided usually by a propellant, jet engine or rocket motor.

<span class="mw-page-title-main">Strategic Defense Initiative</span> U.S. military defense program (1984–1993)

The Strategic Defense Initiative (SDI), derisively nicknamed the Star Wars program, was a proposed missile defense system intended to protect the United States from attack by ballistic nuclear missiles. The concept was announced in 1983, by President Ronald Reagan, a critic of the doctrine of mutual assured destruction (MAD), which he described as a "suicide pact". Reagan called upon American scientists and engineers to develop a system that would render nuclear weapons obsolete. Elements of the program reemerged in 2019 with the Space Development Agency (SDA).

<span class="mw-page-title-main">Shaped charge</span> Explosive with focused effect

A shaped charge is an explosive charge shaped to focus the effect of the explosive's energy. Different types of shaped charges are used for various purposes such as cutting and forming metal, initiating nuclear weapons, penetrating armor, or perforating wells in the oil and gas industry.

<span class="mw-page-title-main">Kinetic energy penetrator</span> High density non-explosive projectile

A kinetic energy penetrator (KEP), also known as long-rod penetrator (LRP), is a type of ammunition designed to penetrate vehicle armour using a flechette-like, high-sectional density projectile. Like a bullet or kinetic energy weapon, this type of ammunition does not contain explosive payloads and uses purely kinetic energy to penetrate the target. Modern KEP munitions are typically of the armour-piercing fin-stabilized discarding sabot (APFSDS) type.

<span class="mw-page-title-main">Reactive armour</span> Type of vehicle armour

Reactive armour is a type of vehicle armour used in protecting vehicles, especially modern tanks, against shaped charges and hardened kinetic energy penetrators. The most common type is explosive reactive armour (ERA), but variants include self-limiting explosive reactive armour (SLERA), non-energetic reactive armour (NERA), non-explosive reactive armour (NxRA), and electric armour. NERA and NxRA modules can withstand multiple hits, unlike ERA and SLERA.

<span class="mw-page-title-main">Armour-piercing ammunition</span> Ammunition type designed to penetrate armour

Armour-piercing ammunition (AP) is a type of projectile designed to penetrate armour protection, most often including naval armour, body armour, vehicle armour.

<span class="mw-page-title-main">Projectile</span> Object propelled through the air

A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found in warfare and sports.

<span class="mw-page-title-main">Railgun</span> Electromagnetic projectile launcher

A railgun or rail gun is a linear motor device, typically designed as a weapon, that uses electromagnetic force to launch high-velocity projectiles. The projectile normally does not contain explosives, instead relying on the projectile's high kinetic energy to inflict damage. The railgun uses a pair of parallel conductors (rails), along which a sliding armature is accelerated by the electromagnetic effects of a current that flows down one rail, into the armature and then back along the other rail. It is based on principles similar to those of the homopolar motor.

<span class="mw-page-title-main">High-explosive anti-tank</span> Type of shaped charge explosive

High-explosive anti-tank (HEAT) is the effect of a shaped charge explosive that uses the Munroe effect to penetrate heavy armor. The warhead functions by having an explosive charge collapse a metal liner inside the warhead into a high-velocity shaped charge jet; this is capable of penetrating armor steel to a depth of seven or more times the diameter of the charge. The shaped charge jet armor penetration effect is purely kinetic in nature; the round has no explosive or incendiary effect on the armor.

<span class="mw-page-title-main">Missile defense</span> System that destroys attacking missiles

Missile defense is a system, weapon, or technology involved in the detection, tracking, interception, and also the destruction of attacking missiles. Conceived as a defense against nuclear-armed intercontinental ballistic missiles (ICBMs), its application has broadened to include shorter-ranged non-nuclear tactical and theater missiles.

<span class="mw-page-title-main">Ranged weapon</span> Any weapon that can engage targets beyond hand-to-hand distance

A ranged weapon is any weapon that can engage targets beyond hand-to-hand distance, i.e. at distances greater than the physical reach of the user holding the weapon itself. The act of using such a weapon is also known as shooting. It is sometimes also called projectile weapon or missile weapon because it typically works by launching solid projectiles ("missiles"), though technically a fluid-projector and a directed-energy weapon are also ranged weapons. In contrast, a weapon intended to be used in hand-to-hand combat is called a melee weapon.

Kill vehicle is a term from space weapon development and science fiction which denotes either a kinetic projectile or an explosive warhead supposed to impact on or near a target. It is the final missile stage of an interceptor weapon.

A kinetic bombardment or a kinetic orbital strike is the hypothetical act of attacking a planetary surface with an inert kinetic projectile from orbit, where the destructive power comes from the kinetic energy of the projectile impacting at very high speeds. The concept originated during the Cold War.

The XM1111 Mid-Range Munition (MRM) is a 120 mm precision guided munition developed for the Rheinmetall Rh-120 120mm gun used by several Western tanks. It was also intended to fulfill a requirement for Future Combat Systems (canceled) for a long-range, beyond line of sight (BLOS) tank munition.

<span class="mw-page-title-main">Explosively formed penetrator</span> Shaped charge designed to penetrate armor effectively

An explosively formed penetrator (EFP), also known as an explosively formed projectile, a self-forging warhead, or a self-forging fragment, is a special type of shaped charge designed to penetrate armor effectively, from a much greater standoff range than standard shaped charges, which are more limited by standoff distance. As the name suggests, the effect of the explosive charge is to deform a metal plate into a slug or rod shape and accelerate it toward a target. They were first developed as oil well perforators by American oil companies in the 1930s, and were deployed as weapons in World War II.

<span class="mw-page-title-main">DF-21</span> MRBM/IRBM

The Dong-Feng 21 (DF-21; NATO reporting name CSS-5 - Dong-Feng is a two-stage, solid-fuel rocket, single-warhead medium-range ballistic missile in the Dong Feng series developed by China Changfeng Mechanics and Electronics Technology Academy. Development started in the late 1960s and was completed around 1985–86, but it was not deployed until 1991. It was developed from the submarine-launched JL-1 missile, and is China's first solid-fuel land-based missile. The U.S. Department of Defense in 2008 estimated that China had 60-80 missiles and 60 launchers; approximately 10-11 missiles can be built annually.

<span class="mw-page-title-main">Lazy Dog (bomb)</span> U.S. airdropped kinetic weapon

The Lazy Dog is a type of small, unguided kinetic projectile used by the U.S. Air Force. It measured about 1.75 inches (44 mm) in length, 0.5 inches (13 mm) in diameter, and weighed about 0.7 ounces (20 g).

<span class="mw-page-title-main">Ammunition</span> Material fired, scattered, dropped, or detonated from a weapon or weapon system

Ammunition is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons and the component parts of other weapons that create the effect on a target.

The DF-ZF is a hypersonic glide vehicle (HGV) developed by the People's Republic of China. It is launched by the DF-17 medium-range ballistic missile. The combined weapon system was likely operational by October 2019.

References

  1. Jain, Mahesh (2009). Textbook of Engineering Physics (Part I). PHI Learning Pvt. p. 9. ISBN   978-81-203-3862-3.
  2. 1 2 3 4 5 6 GlobalSecurity.
  3. Cooper, Paul (1996). Explosives Engineering. Wiley-VCH. p. 406. ISBN   978-0-471-18636-6.
  4. Kalic, Sean (2012). US Presidents and the Militarization of Space, 1946–1967. Texas A&M University Press. p. 57. ISBN   9781603446914.
  5. "Striking a Bullet with a Bullet: HOE". Lockheed Martin. 2020-10-01. Archived from the original on 2023-09-20. Retrieved 2023-10-21.
  6. HeadOn.
  7. "RIM-161 SM-3 (AEGIS Ballistic Missile Defense)". GlobalSecurity.org.

Bibliography