Shoulder-fired missile

The name rocket-propelled grenade (RPG) is regularly used as an informal name for man-portable unguided rocket-launcher systems, a backronym from the Russian acronym РПГ (Ручной Противотанковый Гранатомёт, Ruchnoy Protivotankovy Granatomyot), meaning "handheld anti-tank grenade launcher", the Russian term for infantry-carried anti-tank weapons, not only encompassing rocket-systems (see the RPG-2 for example).

Ammunition traditionally use the backblast principle for propulsion, meaning that when fired, the propellant gases are expelled out of the back of the weapon to alleviate the reactional force exerted from the projectile moving forward.

If the weapon fires ammunition using fixed propellant charges, such as through cartridge cases on reloadable systems or a fixed container on singe-use systems, it is generally called a man-portable or shoulder-launched/fired recoilless rifle or recoilless gun, depending on if it uses a rifled or smoothbore barrel, essentially open-breech cannons.

Such systems typically use a small recoilless charge (a so-called booster charge) or compressed gas system to get the projectile out of the barrel and to a distance where the operator will not be hurt by the rocket's backblast; when the rocket ignites at a safe distance, it further accelerates the projectile or at least keeps it from decelerating in its trajectory.

Rocket-based weapons have a long history, from the black powder fire arrows used by the ancient Chinese to the Congreve rocket referenced in "The Star-Spangled Banner," the national anthem of the United States.

Textual evidence and illustrations of various early rocket launchers are found in the 11th-century Southern Song dynasty text Wujing Zongyao.

This system was not fully developed until the German Panzerfaust of World War II, an early one-shot design that also was the first practical recoilless antitank gun and thus used no rocket.

[clarification needed] From their first conception during the First World War, many portable missiles have been used to give infantry a weapon effective against armored vehicles and fortified structures.

In modern counter-insurgency operations in misty, dusty or night-time situations, advanced optics such as infrared telescopes permit helicopter gunships to observe convoys from beyond human-visible range and still attack insurgents with inexpensive anti-personnel fire.

Shoulder-launched weapons avoid the problem of recoil by directing all exhaust out of the rear of the launch tube, the so-called backblast principle .
Polish soldiers prepare to fire PZR Grom MANPADS.
An illustration of a fire arrow rocket launcher as depicted in the 11th century book Wujing Zongyao . The launcher is constructed using basketry
A German soldier using a Panzerfaust , a single-use light antitank weapon , traditionally fired "under-arm" instead of shoulder-fired like modern systems, Ukraine, 1944.
US-soldiers firing a Swedish AT4 single-use disposable light antitank weapon during familiarization training at the Udari range in Kuwait , 2004.
A JASDF soldier handles a Type 91 Kai MANPADS during exercises as a part of Red Flag – Alaska .
Russian soldier with a single-use disposable RPO-A Shmel rocket flamethrower.