Rocket-propelled grenade

A rocket-propelled grenade, more commonly known as an RPG, is any hand-held, shoulder-launched anti-armor weapon capable of firing an unguided rocket equipped with an explosive warhead. An RPG is an inexpensive way to deliver an explosive payload over a distance with moderate accuracy.

History
The RPG has its roots in the 19th century, with the early development of the explosive shaped charge. The development of practical rocketry provided a means of delivering such an explosive. Research, occasioned by World War II, produced such weapons as the American bazooka, and German Panzerfaust, which combined portability with effectiveness against armored vehicles such as tanks.

Description
An RPG comprises two main parts: the launcher and the rocket, which is equipped with a warhead. The most common types of warheads are high explosive (HE) or high explosive anti-tank (HEAT) rounds. These warheads are affixed to a rocket motor and stabilised in flight with fins. Some types of RPGs are single-use disposable units; others are reloadable.

The RPG launcher is a hollow tube that concentrates the rocket exhaust to create an over-pressure within the tube. This over-pressure propels the warhead at a higher speed than from the specific impulse of the rocket alone. This higher speed is necessary for the rocket to be stable in flight.

The launcher is designed such that the rocket exits the launcher without discharging an exhaust that would be dangerous to the operator. In some cases the rocket is launched by a gunpowder booster charge, and the rocket motor ignites only after 10 metres. In other designs the rocket burns completely within the tube.

In the Halo Universe
In 2535, rioters and Insurrectionists on Charybdis IX used advanced RPGs to destroy an ONI operations truck, as well as shoot down a Pelican dropship piloted by Petty Officer Jeffries. The RPG launchers were later eliminated by ODST snipers.