“The Katyusha was omnipresent on the Eastern Front and likely contributed as much to the Allied victory as the M4 Sherman tank, the Higgins Boat or the Spitfire.”
FOR MANY AMERICANS, the baritone thump-thump-thump of the UH-1 Huey helicopter will forever be associated with the war in Vietnam. For Russians who fought in World War Two, the distinctive whine of the Soviet Katyusha rocket is a sound they will never forget. (♬ Listen Here)
The famous rocket system rolled into battle for the first time mere days into Germany’s invasion of the U.S.S.R. and remained on the front lines all the way through to the Red Army’s final assault on Berlin. In fact, between 1941 and 1945, Soviet factories produced 10,000 of the legendary launchers.
Originally designed as a cheap ad hoc alternative to conventional artillery, the truck-mounted 132-mm Katyusha launcher could fire as many as four-dozen warheads distances of more than six miles (9 km) in a single ten-second burst. While woefully inaccurate when compared to ordinary howitzers, concentrations of Katyushas could shower vast areas with a dense hail of high explosives and then speed to safety before enemy guns could even get a fix on them – a practice known as “shoot and scoot”.
Not surprisingly, German soldiers soon learned to respect and fear the Katyusha. And because of the unmistakable (almost musical) wailing sound the rockets made when they were fired, the Wehrmacht ruefully dubbed the weapon “Stalin’s Organ”.
The Katyusha was omnipresent on the Eastern Front and likely contributed as much to the Allied victory as the M4 Sherman tank, the Higgins Boat or the Supermarine Spitfire. Here are some amazing facts about the Katyusha rocket.
Rocket shells — The Katyusha was first designed to be fired from warplanes, not ground vehicles. Building on the early success of air-to-air rockets in the First World War, Moscow’s bureau of research developed the RS-132 fin-stabilized aircraft “rocket shell” in 1931. Seven years later, the same areal projectiles were modified for army use under the designation M-13.
Powerful punch — The five-foot long, 93-pound rockets were fired from the ground via large steel racks consisting of multiple adjacent launch rails. The entire assembly was designed to be bolted onto the back of ordinary utility trucks. These launch vehicles were known officially as BM-13s. Pre-war testing showed that just four such trucks could unleash the firepower equal to 75 field guns onto a 1.5 square-mile patch of ground in less than half a minute. 
Pros and cons — While the launchers could deliver devastating volumes of firepower, at first commanders in the field were less than enthusiastic about the new weapon. For starters, the rockets were far from accurate. Worse, reloading the empty rails was a ponderous process — it could take a crew nearly an hour to fill a BM-13 with a fresh salvo of a dozen missiles. Despite this, the army brass was pleased with the low cost of the system – each vehicle represented a fraction of the outlay required for a single field gun. And what’s more, launchers could be built in light industrial facilities, whereas the manufacture of artillery required heavy industrial plants.
A secret weapon — Initially, the BM-13 mobile rocket launcher was such a closely guarded secret, only specially cleared NKVD state police units were permitted to operate the weapons. The technology would remain classified well into Russia’s war with Germany.
Combat debut — The rockets were first used in the opening month of the German invasion of the Soviet Union. During a clash near Smolensk on July 14, 1941, just seven of the experimental launchers decimated a German infantry formation in the town of Rudnya.  The barrage struck with such intensity, the Axis troops broke and fled from the city. The demonstration was enough to convince the Soviet high command that the rockets could be a game changer. Detachments of four mobile launchers were quickly raised and sent into battle. By the end of the war, nearly 520 such batteries were in the field.
“Katie” — The name “Katyusha” was not the official designation for the weapon — it was more of an affectionate moniker devised by rank-and-file soldiers. The original BM-13 launchers were manufactured at plant known as the Voronezy Komintern and accordingly bore a large “K” stamp on the side. Troops joked that the letter stood for Katyusha or “Katie” – the name of a popular 1938 folk ballad about a woman who is separated from her lover during wartime (♬ Listen to a modern rendition of the song here). The name soon caught on.
Variants – Not surprisingly, the success of original Katyusha rockets prompted an array of spin-offs. Launchers were fitted onto trucks, jeeps, towed trailers and even T-40 tanks. Super-sized batteries were even mounted on railroad cars and launch rails could also be added to riverboats. Heavier and more devastating 300-mm rockets were fielded before the war’s end as well.
Post-War — Although the Katyusha was introduced as a stopgap alternative to conventional artillery, the design proved so successful that the Red Army continued to refine the concept into the 1950s and 60s. The BM-21 Grad or “Hail” was one such evolution. It could fire up to 40 128-mm M-21 warheads in less than 20 seconds. The improved launchers could also deliver high-explosive fragmentation rounds, anti-tank warheads, smoke bombs, cluster munitions and even land mines. The weapon had a range of 20 km (13 miles).
Hot Commodity – Moscow’s Warsaw Pact allies as well as a number of Soviet client states eagerly snapped up Katyusha-style rocket launchers during the Cold War years. Users of the weapons included Poland, Czechoslovakia, Romania, Yugoslavia, Iran, Egypt, China and North Korea. Many countries even produced their own local versions of the Katyusha or the subsequent BM-21.
Deadly Legacy – While they were initially developed to hammer Nazis on the Eastern Front, you’ve likely seen Katyusha rockets in news footage out some of the world’s most recent hotspots. For example, the systems were used extensively in the Chechen Wars. Saddam’s army launched Katyushas at American forces in the 2003 U.S.-led Iraq Invasion. Insurgents later deployed the same technology in attacks on the Coalition Provisional Authority in Baghdad’s so-called Green Zone. In one famous incident, militants even mounted vintage Katyushas on donkey-carts. In 2006, Hezbollah units in Lebanon hurled as many as 4,000 M-21 rockets into Israel. Sporadic attacks continued right up to this past summer. And throughout June, July and August of 2014, Palestinian militants in Gaza fired salvo after salvo into Israeli territory. The IDF retaliated by bombarding the region heavily. More rocket attacks followed. By the time the fighting had ended five Israeli civilians were dead along with nearly 2,300 Gazans.