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115-570: The A1 was the first rocket design in the Aggregat series. It was designed in 1933 by Wernher von Braun at the German Army research program at Kummersdorf headed by Colonel Dr Walter Dornberger . The A1 was the grandfather of most modern rockets. The rocket was 1.4 metres (4 ft 7 in) long, 30.5 centimetres (12 in) in diameter, and had a takeoff weight of 150 kilograms (330 lb). The engine, designed by Arthur Rudolph , used

230-486: A Charlie Chaplin moustache" and that he perceived him as "another Napoleon " who was "wholly without scruples, a godless man who thought himself the only god". Later examination of von Braun's background, conducted by the United States Federal Bureau of Investigation, suggests that his background check file contained no derogatory information pertaining to his involvement in the party, but it

345-420: A ballistic shell , as centrifugal force would force the liquid fuel to rise up along the walls of their tanks, which made feeding propellants to the combustion chamber difficult. Although the engine had been successfully test fired, the first flight attempt blew up on the launching pad on 21 December 1933, half a second after ignition. The cause was a buildup up of propellants before ignition of its engine. Since

460-652: A catalyst . Von Braun's engines used direct combustion and created fire, while the Walter devices used hot vapors from a chemical reaction, but both created thrust and provided high speed. The subsequent flights with the He-112 used the Walter-rocket instead of von Braun's; it was more reliable, simpler to operate, and safer for the test pilot, Warsitz. SS General Hans Kammler , who as an engineer had constructed several concentration camps , including Auschwitz , had

575-544: A 30 degree range of motion, and when the platform tumbled, the parachutes deployed. The jet vanes needed to move faster, and have a larger control force, to stop the rolling. The fins were redesigned in the A5, when it was realized an expanding jet plume as the rocket gained altitude, would have destroyed the A3 fin stabilizing antenna ring. After this unsuccessful series of launches, the A3 was abandoned and A4 work postponed, while work on

690-759: A Bachelor of Science Degree in Mechanical Engineering from Technische Hochschule Berlin (now Technische Universität Berlin ), Germany. During a period in 1931, von Braun attended the ETH Zürich in Switzerland. During this time in Switzerland, von Braun assisted Professor Hermann Oberth in writing a book concerning the possibilities of creating and manufacturing liquid-propellant rockets. Shortly after this, von Braun founded his own private rocket development business in Berlin, and through which he made

805-486: A French resistance fighter who was a prisoner in Dora, testified in 1995 that, after an apparent sabotage attempt, von Braun ordered a prisoner to be flogged, while Robert Cazabonne, another French prisoner, stated that von Braun stood by as prisoners were hanged by chains suspended by cranes. However, these accounts may have been a case of mistaken identity. Former Buchenwald inmate Adam Cabala stated that von Braun went to

920-476: A Goddard patent". This was independently confirmed. He wrote that statements that he had lifted Goddard's work were the furthest from the truth, noting that Goddard's paper "A Method of Reaching Extreme Altitudes", which was studied by von Braun and Oberth, lacked the specificity of liquid-fuel experimentation with rockets. It was also confirmed that he was responsible for an estimated 20 patentable innovations related to rocketry, as well as receiving U.S. patents after

1035-491: A closed-loop stepper motor is its relatively low cost. There is also no need to tune the PID controller on a closed loop stepper system. The first servomotors were developed with synchros as their encoders. Much work was done with these systems in the development of radar and anti-aircraft artillery during World War II . Simple servomotors may use resistive potentiometers as their position encoder. These are only used at

1150-511: A compact package, brushless AC motors with permanent magnet fields are used, effectively large versions of Brushless DC electric motors . Drive modules for servomotors are a standard industrial component. Their design is a branch of power electronics , usually based on a three-phase MOSFET or IGBT H bridge . These standard modules accept a single direction and pulse count (rotation distance) as input. They may also include over-temperature monitoring, over-torque, and stall detection features. As

1265-591: A conventional runway landing assisted by a drag chute . However, the Air Ministry had no requirement for such an aircraft and the proposal was rejected. Similar concepts (though uncrewed) were produced after the war in the form of the US SM-64 Navaho missile and the USSR's Burya , both intercontinental cruise missiles with ramjet propulsion. The A7 was a winged design that was never fully constructed. It

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1380-583: A copy of Die Rakete zu den Planetenräumen (1923, By Rocket into Planetary Space ) by rocket pioneer Hermann Oberth . In 1928, his parents moved him to the Hermann-Lietz-Internat (also a residential school) on the East Frisian North Sea island of Spiekeroog . Space travel had always fascinated him, and from then on he applied himself to physics and mathematics to pursue his interest in rocket engineering. In 1928

1495-901: A diameter of 0.78 m (2 ft 7 in) and a takeoff weight of 900 kg (2,000 lb). The A5 was fitted with a Brennschluss receiving set, a parachute recovery system, could stay afloat in water for up to two hours, and was painted yellow and red, aiding recovery. New tail surfaces were tested in the Zeppelin Aircraft Works subsonic tunnel and the supersonic tunnel in Aachen. The internal vanes were now made of graphite instead of molybdenum . Uncontrolled A5s were launched from Griefswalder Oie in late 1938. Models that were 1.5 meters (5 ft) long and 20 centimeters (8 in) in diameter were dropped from Heinkel He 111s starting in September 1938, testing supersonic speeds in

1610-509: A diploma in mechanical engineering. His early exposure to rocketry convinced him that the exploration of space would require far more than applications of the current engineering technology. Wanting to learn more about physics, chemistry, and astronomy, von Braun entered the Friedrich-Wilhelm University of Berlin for doctoral studies and graduated with a doctorate in physics in 1934. He also studied at ETH Zürich for

1725-418: A nitrogen tank, a system which was also used for the A3 and A5. Development of the A3 can be traced at least to February 1935 when Major Ernst Ritter von Horstig sent General der Artillerie Karl Becker a budget of almost half a million marks for the construction of two new test stands at Kummersdorf. Included were mobile test rigs, small locomotives, and office and storage space. The A3 plans called for

1840-453: A payload of about a tonne . Versions of the A4 were used in warfare. They included the first ballistic missile and the first projectile to reach outer space . The propellants of choice continued to be liquid oxygen, with a 75% ethanol and 25% water mixture. The water reduced the flame temperature, acted as a coolant, and reduced thermal stress. This increase in capability came from a redesign of

1955-685: A picture of himself standing behind Himmler, von Braun said that he had only worn the SS uniform that one time, but in 2002 a former SS officer at Peenemünde told the BBC that von Braun had regularly worn the SS uniform to official meetings. He began as an Untersturmführer (Second lieutenant) and was promoted three times by Himmler, the last time in June 1943 to SS- Sturmbannführer (Major). Von Braun later stated that these were simply technical promotions received each year regularly by mail. In 1932, von Braun received

2070-410: A pressure-fed rocket propellant system burning ethanol and liquid oxygen , and produced 2.9 kN (660 lbf ) of thrust for 16 seconds. The LOX tank was located within the fuel tank and insulated with a fiberglass material. The rocket was stabilized by a 40 kg (88 lb) 3 axes gyroscope system in the nose, supplied by Kreiselgeräte GmbH. The rocket could not be rotated for stability as with

2185-600: A pullout and enter a shallow glide, trading speed for distance. Patt also proposed the Flossengeschoss (fin projectile). Both concepts were utilized by Walter Dornberger when he drafted a memo for presentation to Hitler regarding the "America rocket" on 31 July 1940. Design studies on the A9 began in 1940. In addition to its wings, the A9 would have been somewhat larger than the A4 and its engine would have produced about 30% more thrust. Following wind tunnel testing of models,

2300-564: A range of 18 kilometres (11 miles). Up to 80 launches by October 1943 developed an understanding of the rocket's aerodynamics, and tests of a better guidance system. The aerodynamic data resulted in a fin and rudder design that was basically the same one used for the A-4. At the conclusion of the A-5 testing, Dornberger stated, "I now knew that we should succeed in creating a weapon with far greater range than any artillery. What we had successfully done with

2415-553: A reputation for brutality and had conceived the idea of using concentration camp prisoners as slave laborers in the rocket program. Arthur Rudolph , chief engineer of the V-2 rocket factory at Peenemünde, endorsed this idea in April 1943 when a labor shortage developed. More people died building the V-2 rockets than were killed by it as a weapon. Von Braun admitted visiting the plant at Mittelwerk on many occasions, and called conditions at

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2530-402: A reserve airfield in the event of war), one of these latter aircraft was flown with its piston engine shut down during flight by Warsitz, at which time it was propelled by von Braun's rocket power alone. Despite a wheels-up landing and the fuselage having been on fire, it proved to official circles that an aircraft could be flown satisfactorily with a back-thrust system through the rear. At

2645-416: A rocket with an inertial guidance system and a 1,500 kg (3,300 lb) thrust engine. In March 1936, Generaloberst Werner von Fritsch witnessed a static firing of an A3 engine at Kummersdorf, and was sufficiently impressed to lend his support to the rocket program. Like the earlier A1 and A2 rockets, the A3 used a pressure-fed propellant system, and the same liquid oxygen and 75% ethanol mixture as

2760-415: A servomotor, and different types may be used. At the simplest, brushed permanent magnet DC motors are used, owing to their simplicity and low cost. Small industrial servomotors are typically electronically commutated brushless motors. For large industrial servomotors, AC induction motors are typically used, often with variable frequency drives to allow control of their speed. For ultimate performance in

2875-411: A simple zero-position sensor to set their position at start-up. Instead of servomotors, sometimes a motor with a separate, external linear encoder is used. These motor + linear encoder systems avoid inaccuracies in the drivetrain between the motor and linear carriage, but their design is made more complicated as they are no longer a pre-packaged factory-made system. The type of motor is not critical to

2990-408: A single expansion nozzle. This was later altered to a large single chamber and single nozzle. Test stands were constructed at Peenemunde for firings of the 200 tonne (440,920 lbf) thrust motor. It was considered that existing guidance systems would not be accurate enough over a distance of 5,000 km, and it was decided to make the A9 piloted. The pilot was to be guided on his terminal glide towards

3105-418: A small area near the ambulance shed, inmates tortured to death by slave labor and the terror of the overseers were piling up daily. But, Prof. Wernher von Braun passed them so close that he was almost touching the corpses. Von Braun later stated that he was aware of the treatment of prisoners, but felt helpless to change the situation. When asked if von Braun could have protested against the brutal treatment of

3220-457: A spaceship and that they felt the war was not going well; this was considered a "defeatist" attitude. A young female dentist who was an SS spy reported their comments. Himmler's unfounded allegations branding von Braun and his colleagues as communist sympathizers and accusing them of sabotaging the V-2 program, coupled with von Braun's regular piloting of a government-provided airplane that could facilitate an escape to Britain, led to their arrest by

3335-431: A specific class of motor, although the term servomotor is often used to refer to a motor suitable for use in a closed-loop control system. Servomotors are used in applications such as robotics , CNC machinery , and automated manufacturing . A servomotor is a closed-loop servomechanism that uses position feedback (either linear or rotational position) to control its motion and final position. The input to its control

3450-431: A speed of 10,080 km/h (6,260 mph), a peak altitude of 56 kilometres (35 mi), and covering 4,000 kilometres (2,500 mi) in about 35 minutes. The spent A-10 would descend by brake flaps and parachute to be recovered in the sea and reused. The A11 ( Japan Rakete ) was a design concept which would have acted as the first stage of a three-stage rocket, the other two stages being the A9 and A10. The A11 design

3565-487: A takeoff weight of 1000 kg. The design had a diameter of 0.38 m and a length of 5.91 m. The A8 was a proposed "stretched" variant of the A4, to use storable rocket propellants (most likely nitric acid & kerosene). The design never reached the prototype stage, but further design work was carried out after the war by a German rocket team in France as the " Super V-2 ". The project was eventually cancelled, but led to

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3680-471: A term from June to October 1931. In 1930, von Braun attended a presentation given by Auguste Piccard . After the talk, the young student approached the famous pioneer of high-altitude balloon flight, and stated to him: "You know, I plan on traveling to the Moon at some time." Piccard is said to have responded with encouraging words. Von Braun was greatly influenced by Oberth, of whom he said: Hermann Oberth

3795-403: Is a signal (either analog or digital) representing the desired position of the output shaft. The motor is paired with some type of position encoder to provide position feedback (and potentially also speed feedback in more sophisticated designs). The controller compares the measured position with the desired position to generate an error signal , which when fed back causes the motor to rotate in

3910-749: The Apollo spacecraft to the Moon. In 1967, von Braun was inducted into the National Academy of Engineering , and in 1975, he received the National Medal of Science . Von Braun is a highly controversial figure widely seen as escaping justice for his awareness of Nazi war crimes due to the Americans' desire to beat the Soviets in the Cold War . He is also sometimes described by others as

4025-607: The Bug River near the village of Sarnaki, and local Poles concealed it before German arrival. The rocket was then dismantled and smuggled across Poland. In late July 1944, the Polish resistance secretly transported parts of the rocket out of Poland in Operation Most III (Bridge III), for analysis by British intelligence. In late 1943 German Labour Front ( Deutsche Arbeitsfront/DAF ) Director, Otto Lafferenz, proposed

4140-527: The Gestapo . Servomotor A servomotor (or servo motor or simply servo ) is a rotary or linear actuator that allows for precise control of angular or linear position, velocity, and acceleration in a mechanical system . It constitutes part of a servomechanism , and consists of a suitable motor coupled to a sensor for position feedback and a controller (often a dedicated module designed specifically for servomotors). Servomotors are not

4255-530: The North Sea . They reached altitudes of 2.2 kilometres (1.4 mi) and 3.5 kilometres (2.2 mi). The A2s had the same dimensions as the A1, and the same engine, but separate propellant tanks. The cylindrical regeneratively cooled combustion chamber was welded inside the ethanol tank. The mushroom-shaped injector system consisted of fuel and oxidizer jets pointing at one another. Propellants were pressurized from

4370-462: The Raketenrummel or "Rocket Rumble" fad initiated by Fritz von Opel and Max Valier was highly influential on von Braun as a teenage space enthusiast. He was so enthusiastic after seeing one of the public Opel-RAK rocket car demonstrations, that he constructed his own homemade toy rocket car and caused a disruption in a crowded sidewalk by launching the toy wagon, to which he had attached

4485-633: The V-2 . In 1963, von Braun reflected on the history of rocketry, and said of Goddard's work: "His rockets ... may have been rather crude by present-day standards, but they blazed the trail and incorporated many features used in our most modern rockets and space vehicles." Goddard confirmed his work was used by von Braun in 1944, shortly before the Nazis began firing V-2s at England. A V-2 crashed in Sweden and some parts were sent to an Annapolis lab where Goddard

4600-556: The V-2 rocket at Peenemünde during World War II . The V-2 became the first artificial object to travel into space on 20 June 1944. Following the war, he was secretly moved to the United States, along with about 1,600 other German scientists, engineers, and technicians, as part of Operation Paperclip . He worked for the United States Army on an intermediate-range ballistic missile program, and he developed

4715-572: The "father of space travel", the "father of rocket science", or the "father of the American lunar program". He advocated a human mission to Mars . Wernher von Braun was born on 23 March 1912, in the small town of Wirsitz in the Province of Posen , Kingdom of Prussia , then German Empire and now Poland. His father, Magnus Freiherr von Braun (1878–1972), was a civil servant and conservative politician; he served as Minister of Agriculture in

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4830-566: The A-5 must be equally valid, in improved form, for the A-4." In the late 1920s, Karl Becker realised that a loophole in the Treaty of Versailles allowed Germany to develop rocket weapons. General Becker was very influential during the development of the A4 until he committed suicide on 8 April 1940 following criticism from Adolf Hitler. The A4 was a full-sized design with a range of about 322 kilometers (200 mi) , an initial peak altitude of 89 kilometers (55 mi) and

4945-587: The A3 engine, now known as the A5, by Walter Thiel . It became clearer that von Braun's designs were turning into useful weapons, and Dornberger moved the team from the artillery testing grounds at Kummersdorf (near Berlin ) to Peenemünde, on the island of Usedom on Germany's Baltic coast, to provide more room for testing and greater secrecy. This version was reliable, and by 1941 the team had fired about 70 A5 rockets. The first A4 flew in March 1942, flying about 1.6 kilometers (1 mi) and crashing into

5060-563: The A4 known alternatively as A9 and A4b, the reason for the dual designation being that the A4 series had received "national priority"; the A4b designation ensured the availability of scarce resources. In June 1939, Kurt Patt of the Peenemünde Design Office , proposed wings for converting rocket speed and altitude into aerodynamic lift and range. As the rocket encountered thicker atmosphere on its descent phase, it would execute

5175-511: The A4's range would be extended to 750 km (470 mi), allowing targets in Britain to be attacked from launch sites within Germany. It was intended that following launch the curve of the A4b's trajectory would become shallower and the rocket would glide toward its target. It was anticipated that interception by enemy aircraft at the end of the glide phase would be almost impossible, as over

5290-454: The A4b still managed to become the first winged guided missile to break the sound barrier and attain Mach 4. A6 was a designation applied to a variant of the A5 test rocket which used different propellants. Some sources indicate that it was also applied to a speculative proposal for a crewed aerial reconnaissance version of the A4b winged variant of the A4. This A6 was initially proposed to

5405-470: The A5 commenced. According to Dornberger, the A3 "...had not been equipped to take any payload. It was a purely experimental missile." Similarly, the A5 was to be "for research purposes only." The A5 played a vital role in testing the aerodynamics and technology of the A4. Its rocket motor was identical to the A-3, but with a new control system provided by Siemens , was 5.825 m (19.11 ft) long, with

5520-458: The A9 would have to have been lightened. In either case, a payload of approximately 300 kg (660 lb) could have been placed in a low Earth orbit, roughly equivalent to the modern-day Electron rocket . The A12 design if built would have been an orbital rocket . It was proposed as a four-stage vehicle, comprising A12, A11, A10 and A9 stages. Calculations suggested it could place as much as 10 tonnes payload in low Earth orbit , comparable to

5635-623: The Baltic Sea. In 1933, von Braun was working on his creative doctorate when the Nazi Party came to power in a coalition government in Germany; rocketry was almost immediately moved onto the national agenda. An artillery captain, Walter Dornberger , arranged an Ordnance Department research grant for von Braun, who then worked next to Dornberger's existing solid-fuel rocket test site at Kummersdorf . Von Braun received his doctorate in physics ( aerospace engineering ) on 27 July 1934, from

5750-453: The Blizna railway line and observed a freight car heavily guarded by SS troops containing " an object which, though covered by a tarpaulin, bore every resemblance to a monstrous torpedo " . Subsequently, a plan was formed to make an attempt to capture a complete unexploded V2 rocket and transport it to Britain. Around 20 May 1944, a relatively undamaged V2 rocket fell on the swampy bank of

5865-575: The Foreign Office in the 1970s, and a younger brother, Magnus von Braun , who was a rocket scientist and later a senior executive with Chrysler . The family moved to Berlin , Brandenburg , in 1915, where his father worked at the Ministry of the Interior. After his Confirmation , his mother gave him a telescope , and he developed a passion for astronomy . Von Braun learned to play both

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5980-620: The French Véronique and Diamant rocket projects. It was proposed to use an advanced version of the A9 to attack targets on the US mainland from launch sites in Europe, for which it would need to be launched atop a booster stage, the A10. Design work on the A10 began in 1940, for a projected first flight to take place in 1946. The initial design was carried out by Ludwig Roth und Graupe and

6095-509: The German Air Ministry as an uninterceptable reconnaissance craft. It would be launched vertically by rocket, taking it to an apogee of 95 km (59 mi); after re-entering the atmosphere it would enter a supersonic glide phase, when its single ramjet would be ignited. It was hoped that this would provide 15 to 20 minutes of cruise at 2,900 km/h (1,800 mph) and would allow the aircraft to return to its base and make

6210-511: The German army until its publication in 1960. By the end of 1934, his group had successfully launched two liquid fuel A2 rockets that rose to heights of 2.2 and 3.5 km (2 mi). Von Braun continued his guided missile work throughout World War Two, and met with Adolf Hitler on several occasions, being formally decorated by Hitler twice, including being awarded the Iron Cross. At

6325-657: The National Socialist Party. At this time I was already Technical Director at the Army Rocket Center at Peenemünde (Baltic Sea). The technical work carried out there had, in the meantime, attracted more and more attention in higher levels. Thus, my refusal to join the party would have meant that I would have to abandon the work of my life. Therefore, I decided to join. My membership in the party did not involve any political activity. It has not been ascertained whether von Braun's error with regard to

6440-725: The Nazi regime, Himmler was conspiring to use Kammler to gain control of all German armament programs, including the V-2 program at Peenemünde. He therefore recommended that von Braun work more closely with Kammler to solve the problems of the V-2. Von Braun stated that he replied that the problems were merely technical and he was confident that they would be solved with Dornberger's assistance. Von Braun had been under SD surveillance since October 1943. A secret report stated that he and his colleagues Klaus Riedel and Helmut Gröttrup were said to have expressed regret at an engineer's house one evening in early March 1944 that they were not working on

6555-473: The Nazis using slave labour to manufacture these rockets. In 1936, von Braun's rocketry team working at Kummersdorf investigated installing liquid-fuelled rockets in aircraft. Ernst Heinkel enthusiastically supported their efforts, supplying a He-72 and later two He-112s for the experiments. Later in 1936, Erich Warsitz was seconded by the RLM to von Braun and Heinkel, because he had been recognized as one of

6670-611: The Party on 12 November 1937, and was issued membership number 5,738,692. Michael J. Neufeld , an author of aerospace history and chief of the Space History Division at the Smithsonian's National Air and Space Museum , wrote that ten years after von Braun obtained his Nazi Party membership, he signed an affidavit for the U.S. Army, though he stated the incorrect year: In 1939, I was officially demanded to join

6785-493: The SG-33 system, to drive the molybdenum-tungsten jet vane control servomotors . The SG-33 was fixed to the rocket, not the stabilized platform, and used three rate gyros to sense roll, pitch and yaw deviations. Two of the jet vanes rotated in the same direction for pitch and yaw control, and in opposite directions for roll control. The guidance and control system was designed by Fritz Mueller , based on Johannes Maria Boykow's ideas,

6900-666: The University of Berlin for a thesis titled "About Combustion Tests." His doctoral supervisor was Erich Schumann. However, this thesis represented only the public aspect of von Braun's work. His actual thesis, entitled "Construction, Theoretical, and Experimental Solution to the Problem of the Liquid Propellant Rocket" (dated 16 April 1934), detailed the construction and design of the A2 rocket. It remained classified by

7015-580: The V-2 rockets, but there were victims on both sides...A war is a war, and when my country is at war, my duty is to help win that war." The engineer who designed the V2, Wernher von Braun, came to be feted as a hero of the space age . The Allies realised that the V-2 was a machine, unlike anything they had developed themselves. — V-2: The Nazi rocket that launched the space age , BBC, September 2014. In response to Goddard's statements, von Braun said "at no time in Germany did I or any of my associates ever see

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7130-625: The absence of a supersonic wind tunnel . Hellmuth Walter also made models of the A5m which included a hydrogen peroxide motor, with potassium permanganate as a catalyst, and were test launched in March 1939. The final fin configuration was wider, curved outward to accommodate the expanding exhaust gases, included external air vanes, but no ring antenna. The A-5, like the A-3, was fueled with ethanol with liquid oxygen as an oxidant . The first successful guided flights were made in October 1939, with three of

7245-400: The basis of the simple and cheap servos used for radio-controlled models . More sophisticated servomotors make use of an absolute encoder (a type of rotary encoder ) to calculate the shaft's position and infer the speed of the output shaft. A variable-speed drive is used to control the motor speed. Both of these enhancements, usually in combination with a PID control algorithm, allow

7360-494: The cause. At first there was some thought of an electrostatic charge that prematurely set off the parachute, but this was largely disproved. Ultimately, the failures were attributed to the inadequate design of the rocket's experimental inertial guidance system and minor instabilities in the body and fin design. The control system was found to be unable to keep the rocket from turning with a wind greater than 3.7 metres per second (12 ft/s). The stable platform gyros were limited to

7475-490: The cello and the piano at an early age and at one time wanted to become a composer. He took lessons from the composer Paul Hindemith . The few pieces of von Braun's youthful compositions that exist are reminiscent of Hindemith's style. He could play piano pieces of Beethoven and Bach from memory. Beginning in 1925, he attended a boarding school at Ettersburg Castle near Weimar , Free State of Thuringia , where he did not do well in physics and mathematics. There he acquired

7590-511: The codename Prüfstand XII (German for "Test Rig XII"). Work on the containers was carried out by the Vulkanwerft , and a single example was completed by the end of the war, but never tested with a rocket launch. In anticipation of the possibility that launch sites might be forced back into the Reich itself, von Braun and his colleagues were pressured to develop a longer-range version of

7705-412: The concentration camp to pick slave laborers: ... also the German scientists led by Prof. Wernher von Braun were aware of everything daily. As they went along the corridors, they saw the exhaustion of the inmates, their arduous work and their pain. Not one single time did Prof. Wernher von Braun protest against this cruelty during his frequent stays at Dora. Even the aspect of corpses did not touch him: On

7820-414: The design was subsequently modified to replace the wings with fuselage strakes , as the tests showed that these provided better lift at supersonic speeds and also solved the problem of transonic shift of the center of lift. Development was suspended in 1941, but in 1944 several V2s were modified to an approximation of the A9 configuration under the designation A4b. It was calculated that by fitting wings,

7935-520: The design was thought to be unstable, no further attempts were made, and efforts moved to the A2 design. The A1 was too nose-heavy, and to compensate, the gyroscope system was moved to the middle of the A2, between the oxygen and ethanol tanks. Static tests and assembly were completed by 1 October 1934. Two A2s were built for a full-out test, and were named after a Wilhelm Busch cartoon, Max and Moritz . On 19 and 20 December 1934, they were launched in front of senior Army officers on Borkum island in

8050-405: The direction needed to bring the shaft to the desired position. The error signal reduces to zero as the desired position is approached, stopping the motor. Simple servomotors use position-only sensing via a potentiometer and bang-bang control of their motor; the motor only rotates at full speed or is stopped. This type of servomotor is not widely used in industrial motion control , but it forms

8165-419: The earlier designs. It generated its 14.7 kN (3,300 lb f ) for 45 seconds. It used a three-gyroscope system to deflect tungsten alloy jet vanes. The design was finished in early 1936 and further modifications that made the rocket stable at supersonic velocities were finalized later that year. The shape of the rocket was based on the 8-mm rifle bullet, in anticipation of supersonic flight. The rocket

8280-520: The encoder type, gearhead ratio, and overall system dynamics are application specific, it is more difficult to produce the overall controller as an off-the-shelf module, and so these are often implemented as part of the main controller. Most modern servomotors are designed and supplied around a dedicated controller module from the same manufacturer. Controllers may also be developed around microcontrollers in order to reduce cost for large-volume applications. Integrated servomotors are designed to include

8395-435: The extreme left and right to establish the end positions. A servomotor can immediately turn to whatever angle the controller instructs it to, regardless of the initial position at power up if an absolute encoder is used. The lack of feedback of a stepper motor limits its performance, as the stepper motor can only drive a load that is well within its capacity, otherwise missed steps under load may lead to positioning errors and

8510-530: The federal government during the Weimar Republic . His mother, Emmy von Quistorp (1886–1959), traced her ancestry through both parents to medieval European royalty and was a descendant of Philip III of France , Valdemar I of Denmark , Robert III of Scotland , and Edward III of England . He had an older brother, the West German diplomat Sigismund von Braun , who served as Secretary of State in

8625-526: The field of astronautics. According to historian Norman Davies , von Braun was able to pursue a career as a rocket scientist in Germany due to a "curious oversight" in the Treaty of Versailles which did not include rocketry in its list of weapons forbidden to Germany. Von Braun was an opportunist who joined the Nazi Party to continue his work on rockets for Nazi Germany . He applied for membership in

8740-481: The first four flights using a Kreiselgeräte complete guidance and control system called SG-52. This used a 3-gyro stabilized platform for attitude control and a tilt program, whose signals were mixed with rate gyros, and fed to a control system connected to the jet vanes by aluminium rods. The Siemens Vertikant control system first flew on 24 April 1940. The Siemens system used three gyros, particularly 3 rate gyros providing stabilization, and hydraulic servomotors to move

8855-515: The first rocket fired by gasoline and liquid oxygen. In 1932, having caught wind of von Braun's rocket business, the German Army connected with von Braun to pursue basic missile research and weather data experimentation. Von Braun said that the German government financed the development of test stands and facilities for experimentation in Darmstadt, Germany. In 1939, von Braun was appointed a technical advisor at Peenemünde Army Research Center on

8970-503: The following year. In 1940, von Braun joined the SS and was given the rank of Untersturmführer in the Allgemeine-SS and issued membership number 185,068. In 1947, he gave the U.S. War Department this explanation: In spring 1940, one SS-Standartenführer (SS-Colonel) Müller from Greifswald, a bigger town in the vicinity of Peenemünde, looked me up in my office...and told me that Reichsführer-SS Himmler had sent him with

9085-423: The idea of a towable watertight container which could hold an A4 rocket. This suggestion progressed to the design of a container of 500 tons displacement to be towed behind a U-boat. Once in firing position, the containers would be trimmed to drop their aft end to a vertical position for launch. The project was dubbed Projekt Schwimmweste (German for "Project Life Jacket") and the containers themselves referred to by

9200-430: The jet vanes to correct pitch and yaw, and control roll. The Möller Askania, or Rechlin system, first flew on 30 April 1940, and used position gyros, a mixing system and a servo system. A-5 testing included a guide plane system for lateral control, and a radio system for propulsion cutoff at a preselected speed, after which the rocket followed a ballistic trajectory . The A-5s reached a height of 12 km (7.5 mi) and

9315-400: The lack of parachute drag allowed them to crash further from the launch site. They reached altitudes between 2,500 feet (760 m) and 3,000 feet (910 m), before falling into the sea. According to another source, one A3 reached a maximum downrange of 12 km (7.5 mi) and maximum altitude of 18 km (11 mi). With each launch a failure, von Braun and Dornberger looked for

9430-783: The largest firework rockets he could purchase. He was later taken in for questioning by the local police, until released to his father for disciplinary action. The incident highlighted the young von Braun's determination to "dedicate his life to space travel". In 1930, von Braun attended the Technische Hochschule Berlin , where he joined the Spaceflight Society ( Verein für Raumschiffahrt or VfR), co-founded by Valier, and worked with Willy Ley in his liquid-fueled rocket motor tests in conjunction with others such as Rolf Engel , Rudolf Nebel , Hermann Oberth or Paul Ehmayr . In spring 1932, he graduated with

9545-403: The late 1930s and early 1940s was complex. He said that he had been so influenced by the early Nazi promise of release from the post–World War I economic effects , that his patriotic feelings had increased. In a 1952 memoir article he admitted that, at that time, he "fared relatively rather well under totalitarianism ". Yet, he also wrote that "to us, Hitler was still only a pompous fool with

9660-533: The later Saturn I rocket of the Apollo program . The A12 stage itself would have weighed around 3,500 tonnes fully fueled, and would have stood 33 m (108 ft) high. It was to have been propelled by 50 A10 engines, fueled by liquid oxygen and ethanol. Wernher von Braun Wernher Magnus Maximilian Freiherr von Braun ( US : / ˈ v ɜːr n ər v ɒ n ˈ b r aʊ n / VUR -nər von BROWN , German: [ˈvɛʁnheːɐ̯ fɔn ˈbʁaʊn] ; 23 March 1912 – 16 June 1977)

9775-458: The matter was of highly political significance for the relation between the SS and the Army, I called immediately on my military superior, Dr. Dornberger. He informed me that the SS had for a long time been trying to get their "finger in the pie" of the rocket work. I asked him what to do. He replied on the spot that if I wanted to continue our mutual work, I had no alternative but to join. When shown

9890-503: The most experienced test pilots of the time, and because he also had an extraordinary fund of technical knowledge. After he familiarized Warsitz with a test-stand run, showing him the corresponding apparatus in the aircraft, he asked: "Are you with us and will you test the rocket in the air? Then, Warsitz, you will be a famous man. And later we will fly to the Moon – with you at the helm!" In June 1937, at Neuhardenberg (a large field about 70 km (43 mi) east of Berlin, listed as

10005-409: The number of steps of movement to rotate, but for this, the controller needs to 'know' the position of the stepper motor on power up. Therefore, on the first power-up, the controller will have to activate the stepper motor and turn it to a known position, e.g. until it activates an end limit switch. This can be observed when switching on an inkjet printer ; the controller will move the ink jet carrier to

10120-457: The order to urge me to join the SS. I told him I was so busy with my rocket work that I had no time to spare for any political activity. He then told me, that...the SS would cost me no time at all. I would be awarded the rank of a[n] "Untersturmfuehrer" (lieutenant) and it were [ sic ] a very definite desire of Himmler that I attend his invitation to join. I asked Müller to give me some time for reflection. He agreed. Realizing that

10235-487: The plant "repulsive", but stated that he had never personally witnessed any deaths or beatings, although it had become clear to him by 1944 that deaths had occurred. He denied ever having visited the Mittelbau-Dora concentration camp, where 20,000 died from illness, beatings, hangings, and intolerable working conditions. Some prisoners state that von Braun engaged in brutal treatment or approved of it. Guy Morand,

10350-563: The rocket. The missile testing ground at Blizna was quickly located by the Polish resistance movement, the Home Army ( Armia Krajowa ), thanks to reports from local farmers. Armia Krajowa field agents managed to obtain pieces of the fired rockets by arriving on the scene before German patrols. In early March 1944, British Intelligence Headquarters received a report of an Armia Krajowa agent (code name: "Makary" ) who had covertly surveyed

10465-506: The rockets that launched the United States' first space satellite Explorer 1 in 1958. He worked with Walt Disney on a series of films, which popularized the idea of human space travel in the U.S. and beyond from 1955 to 1957. In 1960, his group was assimilated into NASA , where he served as director of the newly formed Marshall Space Flight Center and as the chief architect of the Saturn V super heavy-lift launch vehicle that propelled

10580-557: The same time, Hellmuth Walter 's experiments into hydrogen peroxide based rockets were leading toward light and simple rockets that appeared well-suited for aircraft installation. Also, the firm of Hellmuth Walter at Kiel had been commissioned by the RLM to build a rocket engine for the He-112, so there were two different new rocket motor designs at Neuhardenberg: whereas von Braun's engines were powered by alcohol and liquid oxygen, Walter engines had hydrogen peroxide and calcium permanganate as

10695-434: The servomotor to be brought to its commanded position more quickly and more precisely, with less overshooting . Servomotors are generally used as a high-performance alternative to the stepper motor . Stepper motors have some inherent ability to control position, as they have built-in output steps. This often allows them to be used as an open-loop position control, without any feedback encoder, as their drive signal specifies

10810-635: The slave laborers, von Braun team member Konrad Dannenberg (a member of the Nazi party since 1932) told The Huntsville Times : "If he had done it, in my opinion, he would have been shot on the spot." According to André Sellier, a French historian and survivor of the Mittelbau-Dora concentration camp, Heinrich Himmler had von Braun come to his Feldkommandostelle Hochwald HQ in East Prussia in February 1944. To increase his power-base within

10925-599: The system may have to be restarted or recalibrated. The encoder and controller of a servomotor are an additional cost, but they optimize the performance of the overall system (for all of speed, power, and accuracy) relative to the capacity of the basic motor. With larger systems, where a powerful motor represents an increasing proportion of the system cost, servomotors have the advantage. There has been increasing popularity in closed-loop stepper motors in recent years. They act like servomotors but have some differences in their software control to get smooth motion. The main benefit of

11040-577: The target by radio beacons on U-boats and by automatic weather stations landed in Greenland and Labrador . The final design of the A10 booster was approximately 20 m (66 ft) in height. Powered by a 1,670 kN (380,000 lb f ) thrust rocket burning diesel oil and nitric acid, during its 50-second burn it would have propelled its A9 second stage to a speed of about 4,300 km/h (2,700 mph). The A9 would then ignite and accelerate an additional 5,760 km/h (3,580 mph), reaching

11155-458: The target the A-4b was intended to enter a near vertical dive, leaving little time for interception. The A4b concept was tested by fitting swept back wings to two A4s launched from Blizna. Little development work had been carried out, and the first launch on 27 December 1944 was a complete failure. The second launch attempt, on 24 January 1945, was partially successful, in that the wing broke off, but

11270-410: The technical director of Kreiselgeräte GmbH ("Gyro Instruments Limited"). The A3 engine was a scaled-up version of the A2, but with a mushroom-shaped injector at the top of the combustion chamber, based on a design by Walter Riedel . Ethanol was sprayed upwards to mix with the oxygen sprayed downward from jets at the top of the chamber. This increased efficiency and generated higher temperatures. This

11385-485: The time, Germany was highly interested in American physicist Robert H. Goddard 's research. Before 1939, German scientists occasionally contacted Goddard directly with technical questions. Von Braun used Goddard's plans from various journals and incorporated them into the building of the Aggregat (A) series of rockets. The first successful launch of an A-4 took place on 3 October 1942. The A-4 rocket became well known as

11500-735: The very simplest and cheapest level and are in close competition with stepper motors. They suffer from wear and electrical noise in the potentiometer track. Although it would be possible to electrically differentiate their position signal to obtain a speed signal, PID controllers that can make use of such a speed signal, generally warrant a more precise encoder. Modern servomotors use rotary encoders , either absolute or incremental . Absolute encoders can determine their position at power-on but are more complicated and expensive. Incremental encoders are simpler, cheaper, and work at faster speeds. Incremental systems, like stepper motors, often combine their inherent ability to measure intervals of rotation with

11615-480: The war concerning the advancement of rocketry. Documented accounts also stated he provided solutions to a host of aerospace engineering problems in the 1950s and 1960s. On 22 December 1942, Adolf Hitler ordered the production of the A-4 as a "vengeance weapon", and the Peenemünde group developed it to target London. Following von Braun's 7 July 1943 presentation of a color movie showing an A-4 taking off, Hitler

11730-437: The water. The second launch reached an altitude of 11 kilometers (7 mi) before exploding. The third rocket, launched on 3 October 1942, followed its trajectory perfectly. It landed 193 kilometers (120 mi) away, and reached a height of 83 kilometers (52 mi) . The highest altitude reached during the war was 174.6 kilometres (108.5 miles) on 20 June 1944. Production started in 1943 on

11845-467: The year was deliberate or a simple mistake. Neufeld wrote: Von Braun, like other Peenemünders, was assigned to the local group in Karlshagen; there is no evidence that he did more than send in his monthly dues. But he is seen in some photographs with the party's swastika pin in his lapel – it was politically useful to demonstrate his membership. Von Braun's later attitude toward the Nazi regime of

11960-484: Was 6.7 metres (22 ft) in length, 0.70 metres (2.3 ft) feet in diameter, and weighed 750 kg (1,650 lb) when fueled. Fins were included, for "arrow stability", structurally anchored by an antenna ring. The stabilized platform used a pitch gyro and a yaw gyro, connected to pneumatic servos, which stabilized the platform along the pitch and yaw axes. Electrical carriages on the platform acted as integrating accelerometers. These signals were mixed with those from

12075-584: Was a German-American aerospace engineer and space architect . He was a member of the Nazi Party and Allgemeine SS , the leading figure in the development of rocket technology in Nazi Germany , and later a pioneer of rocket and space technology in the United States . As a young man, von Braun worked in Nazi Germany's rocket development program. He helped design and co-developed

12190-547: Was completed on 29 June 1940. Hermann Oberth worked on the design during 1941, and in December 1941 Walter Thiel proposed that the A10 use an engine composed of six bundled A4 engines, which it was thought would give a total thrust of 180 tonnes. Work on the A10 was resumed in late 1944 under the Projekt Amerika codename, and the A10's design was amended to incorporate a cluster of 6 A4 combustion chambers feeding into

12305-507: Was doing research for the Navy. If this was the so-called Bäckebo Bomb , it had been procured by the British in exchange for Spitfires ; Annapolis would have received some parts from them. Goddard is reported to have recognized components he had invented and inferred that his brainchild had been turned into a weapon. Later, von Braun said: "I have very deep and sincere regret for the victims of

12420-417: Was found that he had numerous letters of commendation for outstanding performance of duties during his time working under the Nazi party. Overall FBI conclusions point to von Braun's involvement in the Nazi Party to be purely for the advancement of his academic career, or out of fear of imprisonment or execution. Von Braun joined the SS horseback riding school on 1 November 1933 as an SS- Anwärter . He left

12535-496: Was launched toward England on 7 September 1944, only 21 months after the project had been officially commissioned. Doug Millard of the Science Museum, London states: The V-2 was a quantum leap of technological change. We got to the Moon using V-2 technology but this was technology that was developed with massive resources, including some particularly grim ones. The V-2 programme was hugely expensive in terms of lives, with

12650-525: Was salvaged and most of the engineering team remained unharmed; however, the raids killed von Braun's engine designer Walter Thiel and Chief Engineer Walther, and the rocket program was delayed. The V-2 became the first artificial object to travel into space by crossing the Kármán line with the vertical launch of MW 18014 on 20 June 1944. The first combat A-4, renamed the V-2 ( Vergeltungswaffe 2 "Retaliation/Vengeance Weapon 2") for propaganda purposes,

12765-604: Was shown by von Braun to US officers in Garmisch-Partenkirchen; the drawing was published in 1946 by the US Army. The A11 was shown as using six of the large single-chamber engines proposed for the A10 stage, with a modified A10 second stage nested within the A11. The design also showed the winged A9, indicating a gliding landing or bombing mission. To achieve orbit, either a new "kick stage" would have been required, or

12880-491: Was so enthusiastic that he personally made von Braun a professor shortly thereafter. By that time, the British and Soviet intelligence agencies were aware of the rocket program and von Braun's team at Peenemünde, based on the intelligence provided by the Polish underground Home Army . Over the nights of 17–18 August 1943, RAF Bomber Command 's Operation Hydra dispatched raids on the Peenemünde camp consisting of 596 aircraft, and dropped 1,800 tons of explosives. The facility

12995-491: Was the first of the Aggregat rockets to be launched from the Peenemünde area. As part of Operation Lighthouse the first A3 was launched on 4 December 1937, but suffered problems with premature parachute deployment and engine failure, and crashed close to the takeoff point. The second launch on 6 December 1937 suffered similar problems. The parachute was disabled in the third and fourth rockets launched on 8 and 11 December 1937, but these, too, experienced engine failures, though

13110-429: Was the first who, when thinking about the possibility of spaceships, grabbed a slide-rule and presented mathematically analyzed concepts and designs... I, myself, owe to him not only the guiding-star of my life, but also my first contact with the theoretical and practical aspects of rocketry and space travel. A place of honor should be reserved in the history of science and technology for his ground-breaking contributions in

13225-524: Was worked on between 1940 and 1943 at Peenemünde for the Kriegsmarine . The A7 was similar in structure to the A5, but had larger tail unit fins (1.621 m) in order to obtain greater range in gliding flight. Two unpowered models of the A7 were dropped from aeroplanes in order to test flight stability; no powered test was ever performed. The finished rocket should have produced a takeoff thrust of 15 kN and

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