What was the first multiple-launch rocket launcher?

The world's first multiple-launch self-propelled rocket launcher was the BM-13 (commonly known as the Katyusha), developed by the Soviet Union in 1933.

Katyusha

Katyusha rockets are equipped with multiple orbital directional devices, a single volley can fire 16 rounds of 132 mm rockets, the maximum range of 8,500 meters, the rockets are tailed, the initial velocity of 70 m/s, the maximum speed of 355 m/s. The rocket can be reloaded at any time. The reloading time of the rocket launcher is about 5 to 10 minutes. Because the rocket launcher fires a large fire, it is easy to expose the position, so the designers mounted the Katyusha rocket launcher on the car, so that it has a good mobility, can be quick to fight and quickly move.

On June 30, 1941, the Voronezh region's "*** Producers International" arsenal was given the task of mass-producing the BM-13 rocket launcher. For the sake of secrecy, the factory marked its rockets with the letter "K", which was the first letter of the arsenal's Russian name.

On July 14, 1941, the Soviets used Katyusha rockets for the first time in the Orsha region, dealing a fatal blow to the Germans. The rocket launcher became famous in this battle because of its fierce firepower, its ability to fire a large number of rockets in a very short time and its unique shape. At that time, the officers and soldiers did not know the name of this new type of gun, and saw the "K" on the gun carriage, then associated with the Soviet song familiar Russian girl's name Katyusha. Since then, the BM-13 rocket launcher has been known throughout the Soviet Union and the world under the name "Katyusha". "Katyusha" this new type of artillery in the Soviet Union in the Patriotic War made great achievements, and therefore loved by the soldiers.