The V-2 (), with the technical name Aggregat 4 (A-4), was the world’s first long-range guided ballistic missile. The missile, powered by a liquid-propellant rocket engine, was developed during the Second World War in Nazi Germany as a "vengeance weapon" and assigned to attack Allied cities as retaliation for the Allied bombings of German cities. The rocket also became the first artificial object to travel into space by crossing the Kármán line (edge of space) with the vertical launch of MW 18014 on 20 June 1944. Research of military use of long-range rockets began when the graduate studies of Wernher von Braun was noticed by the Wehrmacht. A series of prototypes culminated in the A-4, which went to war as the . Beginning in September 1944, more than 3,000 were launched by the Wehrmacht against Allied targets, first London and later Antwerp and Liège. According to a 2011 BBC documentary, the attacks from resulted in the deaths of an estimated 9,000 civilians and military personnel, and a further 12,000 forced laborers and Nazi concentration camps prisoners died as a result of their forced participation with the production of the weapons. The rockets travelled at supersonic speed, impacted without audible warning, and proved unstoppable, as no effective defense existed. Teams from the Allied forces—the United States, the United Kingdom, and the Soviet Union—raced to seize major German manufacturing facilities, procure the Germans' missile technology, and capture the V-2’s launching sites. Von Braun and more than 100 important personnel surrendered to the Americans, and many of the original team ended up working at the Redstone Arsenal. The US also captured enough hardware to build approximately 80 of the missiles. The Soviets gained possession of the manufacturing facilities after the war, re-established production, and moved it to the Soviet Union. Development history During the late 1920s, a young Wernher von Braun bought a copy of Hermann Oberth's book, Die Rakete zu den Planetenräumen (The Rocket into Interplanetary Spaces). The world's first large-scale experimental rocket program was Opel-RAK directed by Fritz von Opel and Max Valier, a collaborator of Oberth, during the late 1920s resulting in the first manned rocket cars and rocket planes, which provided the basis for the Nazi era V2 program and US and Soviet activities from 1950 onwards. The Opel RAK program and the spectacular public demonstrations of ground and air vehicles drew large crowds, as well as caused global