Operating at a secret laboratory at Peenemünde on the Baltic coast, the V–2 rocket was the immediate antecedent of those used in space exploration programs in the United States and the Soviet Union. A liquid propellant (LOX/ethanol) missile some 46 feet in length and weighing 27,000 pounds, the V-2 flew at speeds in excess of 3,500 miles per hour and delivered a 2,200-pound warhead to a target 500 miles away. First flown in October 1942, it was employed against targets in Europe beginning in September 1944. By the beginning of 1945, it was obvious to von Braun that Germany would not achieve victory against the Allies, and he began planning for the postwar era.
The weapons were an extreme concern for the Allies, who had no defense against them. The only way to prevent a V-2 from hitting its target was to destroy it before it was launched. This was typically done by fighter-bombers or, for large compounds, strategic bombers such as the B-17.
More slave laborers died manufacturing the missiles in underground factories than were killed by the missile attacks.[Citation Needed]
After the war, the United States used the V-2 as the prototype for missiles such as the Jupiter.