V2 rocket

The V2 rocket (from German: Vergeltungswaffe 2, "retaliation weapon 2"), technical name A4 ( Aggregat 4), was a ballistic missile developed at the end of World War II in Nazi Germany used specifically against Belgium and locations in the southeast of England. This rocket was the world's first long-range combat ballistic missile and the first known human device to make a suborbital flight, making it the first artificial object to reach space. It was the progenitor of all rockets modern ones, including those used by the United States and Soviet space programs, which had access to German scientists and designs through Operation Paperclip and Operation Osoaviakhim, respectively.

The German Wehrmacht launched around 5,000 V2 military rockets against Allied targets during the war, mainly London and later Antwerp, resulting in the deaths of an estimated 7,250 people, both civilian and military.^{[citation needed]} The weapon was presented by Nazi propaganda as revenge for the bombings of German cities from 1942 until the end of the war.^{[citation required]} Platzes: Penemünde, Podlipki near Mutizhschzi, Seliger, Kapustin Jahr (Astrachan').

Description

Designed by Wernher von Braun, many of these missiles were fired from the French coast towards London in order to cause as much devastation as possible, as well as undermine enemy morale. Successor to the V1 (which was a cruise missile), this design did not see the light of day until very late in the war, so it had little real impact on it.

The V2 was one of the most relevant advances in weapons technology achieved up to that time. However, he could not change the course of the war, which had already taken a decisive turn in 1944 towards Allied victory.

Background

Experiments with liquid fuel rockets began in Germany in the 1920s, promoted by the space flight society "Verein für Raumschiffahrt" (or "VFR"), among whose members was the young Wernher von Braun (1912- 1977).

Later, in 1934, these works, originally civilian, were transformed into official activity financed and controlled by the Wehrmacht under the direction of the captain, then general, Walter Dornberger, granting them research facilities in Kummersdorf, Brandenburg. In 1937 the team moved to Peenemünde, on the Baltic coast, with Dornberger as boss and Von Braun as technical director.

These scientists sought to increase the effectiveness of rockets and turn them into viable weapons. To this end, a series of test vehicles powered by alcohol and liquid oxygen (including the “Aggregat Eins” or A1, A2 and A3) were carried out, as well as extensive static tests.

V2

Around 1935, the main project was the construction of a large artillery rocket, for which the name "A4" was chosen. To achieve this, the design characteristics and various control techniques would be tested on a scale model: the “A5”. In this way, at the end of 1941 the A4 was finished and on June 13, 1942 the first example was tested. But it failed to take flight, fell on its side and exploded. The second example, launched on August 16, 1942, flew for 45 seconds until it began to oscillate and finally broke up in the air. The third missile made the first successful full flight on October 3 of the same year, reaching a maximum height of 5 km and falling at a distance of 190 km.

German Chancellor Adolf Hitler, excited by the success, ordered the mass production of the A4 under the name "Vergeltungswaffe 2" (retaliation weapon number 2) or simply "V2", intended to attack London and British soil because It was not effective against military targets due to its poor accuracy. The rocket formed a large explosion that caused serious damage in its impact radius.

Features

The V2 had been conceived as an extension of artillery and was therefore planned as a mobile weapon. For the sake of that, its gauge was the maximum that could pass through a railway tunnel. Although Hitler was in favor of fixed launching bases, La Coupole and Eperlecques, which began to be built in northern France, several bombing raids, some including Tallboy bombs, as part of Operation Crossbow, damaged them and they were taken before they were operational. The missile was transported on a wheeled transporter-erector called "Meilerwagen", which had a hydraulic system that raised the tip of the missile until it was placed at an angle of 90° with respect to the ground, on a rotating base on a launching device. The "Meilerwagen", in turn, was towed by a tractor vehicle. The complete team needed another 30 vehicles, which marched in convoy (generally at night), transporting the propellants, the warhead, a mobile crane to assemble it, command and control utensils, and autogenous equipment for power supply, among other things.

At the top of the missile was the warhead, which weighed 975 kg, of which 910 were the explosive charge. The explosive substance was amatol, a product with no risk of premature explosion even when the A4 re-entered the atmosphere and the outer casing of tempered steel turned dark red (600 °C) due to friction with the air.

The guidance system was simple: once the rocket was in the launch position, the top plate of the launch platform was rotated until the missile was aligned exactly in azimuth with the direction of the target. After launch, two Lev-3 gyroscopes and integrated accelerometers (which made up the inertial guidance of the device) tilted the body of the missile at the necessary angle and cut off the main engine at the precise speed, so that its ballistic trajectory ensured reaching the target.. The apogee was normally around 96 km (which then represented the highest height reached by any man-made object).

When ascending, the A4s slowly tilted until they reached an angle of 40° or 45° in relation to the vertical, depending on the distance from the target. Then, once the trajectory was established after 68 seconds, the engine was cut off. The total flight time from takeoff to landing was about four minutes.

Control was carried out by means of four graphite flow vectoring deflectors (blades) located in the gas jet, which gave stability to the missile, and by means of small aerodynamic rudders installed on the four large fins, which were effective once reached high speed.

The A4 rocket engine was fed with liquid oxygen and alcohol at high pressure using a 730 HP Walter turbopump that ran on superheated steam. This was generated in a reaction chamber by the catalytic decomposition of T-Stoff (hydrogen peroxide concentrate) by C-Stoff (calcium permanganate solution). Once the turbopump started, it began to transfer the propellants. The liquid oxygen was directed through a distributor to the injectors in the combustion chamber, and the alcohol reached those same injectors through the double wall of the nozzle, in order to provide essential cooling to it.

The ignition of the propellants was electrical, using an electric arc. Once the engine was started, the A4 ran for a few moments before beginning the flight. When leaving the takeoff platform, the acceleration was increasing as fuel consumption reduced the weight and the decrease in external pressure due to height increased the thrust. The A4 was the first missile to exceed the speed of sound.

The reaction time from arrival at an unprepared site was about six hours. Locations were carefully chosen to obtain the exact geographical position to calculate the precise azimuth of the target. These places were almost always forest clearings, which provided protection from aerial reconnaissance and also sheltered the wind rocket.

Once arriving at the launch site, the missile was hoisted to the vertical position. Then the transport vehicle moved away, with which access to the missile was through a 14 m high platform. Then the loading of 70% ethyl alcohol (3750 kg) began, and the personnel checked the gyroscopes and accelerometers in the guidance compartment. At this point the missile was aligned with the azimuth of the target. This was followed by numerous checks and measurements. In the last two hours, the intensely cold (t < -182.96°C) liquid oxygen (1970 kg) was pumped into the interior with great care. Finally, the fluids were loaded to drive the turbopump. Once the latter were loaded, the A4 was treated with the greatest of precautions. In the final minutes, the telemetry system (installed occasionally to record the trajectory achieved) was activated in connection with four antennas located at the ends of the fins; At that time it was already ready for launch.

Production and use

Preliminary production of the A4 began at a plant south of Peenemünde, but the air raid on August 17, 1943, although it failed to destroy the plant, killed chief engineer Professor Tier and some 600 foreign workers. This delayed production by about two months and mass production was tasked to the colossal underground factory Mittelwerk, where 50,000 forced laborers produced 300 units in April 1944 and more than 1,000 in October.

The use of the A4 in the war began on September 6, 1944, when the army already had 1,800 missiles in storage and the units specialized in the use of the device were ready. That day two shots were fired against Paris, but they were inaccurate. The training of launch operators took place mainly in Karpatenvorland. There, between January 1944 and February 1945, some 600 A4s were fired in training. On September 8, the attack on London began. Initially, the British government told the public that the explosions were caused by faulty gas pipes. However, a few days later the truth had to be admitted. Nazi propaganda then revealed the existence of retaliation weapon number 2 or V2. Unlike what happened with the V1, the V2 were invulnerable, as they reached supersonic speeds and not even the fastest fighters of the time could intercept them, nor could anti-aircraft artillery shoot them down. Furthermore, when fired from mobile launchers, locating their bases was quite problematic. The height and speed reached by the V2s also made it practically impossible to detect them with the radar of the time. It is true that at the time of launch the missile could be seen by allied pilots (who had complete control of the skies at that time), but although several enemy fighters tried to destroy the A4 during takeoff, none succeeded. In short, the Germans had created a weapon against which there was no possible defense. From September 8, 1944 to March 27, 1945 (when the last V2 fell on England), some 4,320 V2s were launched against Allied territory. Of these, more than 1,400 were directed against England, of which 1,054 reached their objective and the remainder exploded at some point along their trajectory, or made gross errors in direction. In 1945 1,675 V2s were fired against Antwerp and the Allied forces at Aachen. Total V2 production exceeded 10,000 units before the end of the war.

The damage caused by the impact was similar to that of the V1, but the losses were greater due to the lack of warning. This was because, when crashing at supersonic speeds, no approach noise was perceived. Thus, after hearing the deafening explosion, long crashes came that died down, just like thunder. To increase the range of the V2 to 750 km, the A4b was designed, equipped with swept wings and longer aerodynamic rudders. Two examples were tested between the end of 1944 and the beginning of 1945 with little success.

Another futuristic design was the so-called A9/A10, which envisaged a two-stage missile, twice the size of the A4, which would have a range of 4,800 km and could have been the first intercontinental ballistic missile.

Postwar

After the war, the V2s captured by the Allies underwent extensive testing. German scientists involved in missile and rocket technology were the best at the time. Therefore, after World War II, the United States and the USSR strove to obtain the majority of these specialists, being used to explore and probe the upper atmosphere. The PGM-11 Redstone is a direct descendant of the V-2. Braun and his team created NASA's Saturn V rocket, which took man to the Moon in 1969 with the Apollo Program. The Soviets also employed German personnel but they were repatriated in the 1950s and subsequent development was carried out with indigenous personnel. They began by making a copy, the R-1 (SS-1 Scunner). Project 1059 or better known as the Dong Feng-1 is a Chinese version, possibly derived from the Soviet R-1. The Soviet Scud missile is directly based on the V-2.^{[citation needed]}