THE V–2 ROCKET

The V–2 rocket was the world’s first long-range ballistic missile, and it comprised five major subassemblies: warhead, control compartment, midsection, propulsion unit, and tail unit.

The 2,200-pound warhead consisted of 550 pounds of warhead casing and 1,650 pounds of explosive. The warhead used an impact-detonating two-fuse system that withstood the six-g acceleration and vibration of powered flight. The powerful explosive had to be insensitive to the heat and shock of flight.

The V–2 developers also knew that the weapon’s power would mean little if it did not strike accurately. The trajectory of the single-stage rocket had two phases: powered flight and ballistic flight. Only during the powered ascent could the rocket be controlled. After its engine cut off, the V–2 followed a trajectory like any other artillery shell. Immediately after launch, the V–2 would begin its preprogrammed pitch, or elevation angle. On the proper azimuth, or heading, this elevation angle would be maintained until the rocket attained the speed to reach its intended target. Then the V–2 engine would be cut off, either by an on-board device or by radio control. During ballistic flight, the V–2 reached an altitude of fifty miles and had a velocity of 1,800 mph on impact.

The rocket motor, fueled from tanks of alcohol and liquid oxygen located in the midsection, produced 56,000 pounds of thrust, enabling the weapon to achieve speeds of 3,355 mph. The V–2 engine had three sections: the steam generator, the turbopump, and the combustion chamber. The steam generator supplied the steam to drive the turbopump. The turbopump forced the alcohol and oxygen into the combustion chamber, the bulk of the powerplant, where they were ignited to generate thrust. The exhaust from the engine could be directed by vanes located in the V–2 tail assembly, which also included four fins to direct the V–2 during atmospheric flight. In concert, the vanes and fins, each with a servo and an electric motor, could control the rocket around the three axes of yaw, pitch, and roll.

Configured for launch, the V–2 measured 46 feet in length, 5.4 feet in diameter, and had a fin span of 11.7 feet.