Dr Walter Dornberger. (Author, Courtesy HTM Peenemünde)
Although the German Army (Heer) Weapons Agency, given the name Heeres Waffenamt (HWA) in 1922, already incorporated a research and development department, the Heereswaffenamt Prüfwesen (Wa Prüf), the serious work on German military rockets did not begin until 1931, when Captain Walter Dornberger took the lead with a team of aspiring rocketeers, including Rudolf Nebel, Klaus Riedel, Heinrich Grünow and the rising star Wernher von Braun. Making good use of the fundamentals prescribed by Hermann Oberth, they were to kick-start the nation’s rocket development in its new direction – that of military application, under the ever watchful eyes of the Wehrmacht (German Armed Forces). This was grist to the mill for Dornberger, a gunnery officer who recognised the limitations of artillery, with even the mighty, but hardly mobile ‘Paris Gun’, limited to some eighty miles in range, with a relatively small projective, a low rate of fire and poor accuracy. He saw the rocket more as a supplement or alternative to long-range artillery than as a replacement for the manned bomber aircraft and believed that, initially, he could double the maximum range achieved by contemporary artillery with a rocket carrying a one-ton warhead. Ultimately he hoped to build a successor weighing 100 tons, with a 10-ton warhead over ever greater ranges –and the Aggregate (Aggregate) series of rockets was a first step in that direction.
Dornberger’s new group was based first at the old military range at Kummersdorf, south of Berlin, and it was there that its first rocket, the Aggregate 1 (A1), was tested on 21 December 1932. The A1, 4 feet 7 inches long and 1 foot in diameter, had a take-off weight of 330lb; it was fuelled by a mixture of alcohol and liquid oxygen, to generate 300 pounds of thrust for 16 seconds. This first attempt was a failure, with the A1 blowing up on the launch pad, and because it was suspected that the heavy gyroscope installed in the nose would also render it unstable in flight, the A1 was abandoned in favour of the A2. This was a larger rocket, 5 feet 3 inches long and weighing 236lb, powered by a new engine producing 3,000 pounds of thrust for 50 seconds. This time the stabilisation gyroscopes were positioned in the centre of the rocket’s body, between the oxygen and alcohol fuel tanks. Two A2s, named Max and Mintz (after the cartoon characters of that time) were launched on 19 and 20 December 1934 respectively, from a Baltic site at Borkum, where a large group of military and civilian VIPs, watched them climb to heights above 10,000 feet.
In a historic milestone which would have worldwide consequences, Hitler unilaterally repudiated the Treaty of Versailles in 1935, freeing Germany from all the military constraints it had imposed. This released unprecedented funds for a massive rearmament programme and gave rocket development new impetus. Within the reorganisation of the German Ordnance Department, the rocket group was designated Wa Prüf 11 (Weapons Testing Branch 11). Dornberger guarded this branch jealously, but he needed all the help he could get to further his cause, so he welcomed the interest shown by Lieutenant Colonel Wolfram von Richthofen, head of the Air Ministry Technical Office and cousin of that legendary First World War pilot, the ‘Red Baron’, in the use of rockets to power a fighter fast enough to compete with the Allied aircraft then in the pipeline. To that end, von Richthofen visited Kummersdorf first in January 1935 and joined members of Wa Prüf 11, the Air Ministry and the aircraft designer, Willy Messerschmitt, when they visited the independent German engineer Paul Schmitt, who was developing a pulse-jet engine for both missiles and aircraft. In this Schmitt failed but valuable lessons were learned from his research, which would help the Argus engine company to perfect a pulse-jet engine for the flying bomb which would be nurtured later by the Luftwaffe (German Air Force).
Dr Walter Dornberger. (Author, Courtesy HTM Peenemünde)
By 1936 the facilities at Kummersdorf had been greatly improved, with two new static test stands, mobile test rigs and the extensive support facilities necessary to accommodate the much larger A3. The A3 measured 22 feet long and 2 feet 4 inches in diameter and weighed 1,650lb at lift-off; its engine provided 3,300 pounds of thrust for 45 seconds, using a pressure-fed propellant of liquid oxygen and ethanol, and it carried an inertial guidance system. The problem of how to stabilise the rocket without the rotation imparted to a shell in the rifled barrel of a gun was solved by incorporating a simple but reliable gyroscope-based ‘autopilot’, designed by Dr Karl Fieber and produced by Kreiselgeräte GmbH (Gyro Devices Ltd). The A3 had narrow fins, to give aerodynamic stability at supersonic speeds, telemetry to measure temperatures and pressures in flight and a radio receiver, using on-board power, to take commands from the ground to shut the engine down in the air. German rocket development was gathering pace.
The First World War ‘Paris Gun’ set standards for the Second World War. (Author, Courtesy HTM Peenemünde)
Aggregate A2, the beginnings of a military rocket. (Author, Courtesy HTM Peenemünde)
Despite the improvements at Kummersdorf, it soon became clear that the weapons range there was too small to accommodate new technologies or serve all potential users, and too open to public scrutiny, so the search began for a more suitable alternative. The Baltic island of Rügen came to mind, but this had been commandeered by the all-powerful German Labour Front as a ‘strength through joy’ recreational area, an initiative known to be greatly favoured by Adolf Hitler – and so inviolate. It was Werner von Braun who found an ideal site, on the Baltic Island of Usedom where his father used to go duck hunting, specifically the Peenemünde peninsula to the north of the island, and it was there that the HWA established one of its most important weapons proving grounds: Heeresversuchsanstalt Peenemünde (HVP)
Usedom, sixty miles long and twenty-eight wide, was indeed a very suitable location for rocket research and development. The peninsula consisted largely of flat, sandy soil, much of which was covered by pine forests; it had a scattering of settlements, with Peenemünde village in the north-west offering a small port. Monitoring equipment, sited along a 250-mile stretch of the Baltic/Pomeranian coastline to the east, would allow rocket flights to be tracked after launch from Peenemünde, while restricted access to the island gave a high measure of security. Moreover, the tiny island of Greifswalder Oie, north-north-east of Peenemünde, could be an invaluable adjunct to the main range on Usedom.
So it was that, on 2 April 1936, the German Air Ministry paid the local town of Wolgast 750,000 Reichsmarks for the whole of the northern peninsula, the cost shared between the German army and air force. The village of Peenemünde was evacuated and work began on the infrastructure, the air force taking the lead in the construction, unfettered by the army’s traditional ways and conventional wisdoms. This resulted in state-of-the-art research, development, test and production installations, unrivalled anywhere in the world, with the army and air force occupying two distinct sectors.
The Army Research Centre was located at Peenemünde Ost (Peenemünde East), sub-divided into Werk Ost (Eastern Works) and Werk Süd (Southern Works). To the north-east, where the forest gave way to a sandy shoreline, nine rocket test stands were built, the largest and most prominent being Test Stand VII, from which most of the surface-to-surface rockets would be launched, while three more stands, for rocket engine tests, were sited northwest of Karlshagen. Farther north on the peninsula, at Werk West (Western Works), lay the Air Force Test Site, with its rudimentary airfield, test stands and flying-bomb launch pads.
Peenemünde Power Station, looking north, largely unscathed by Allied bombing, survives to this day. (Author, Courtesy HTM Peenemünde)
Peenemünde’s Liquid Oxygen Plant – still standing in 2013. (Author, Courtesy HTM Peenemünde)
The Peenemünde Peninsula. (Author’s Collection, Courtesy HTM Peenemünde)
Between the army and air force sections, a huge, 30,000-KW, coal-fired power station and a liquid oxygen factory, fundamental to the new technologies, each served the whole complex, while an electric railway linked all its main components. To the south, a well-landscaped housing estate was built to accommodate the ‘privileged’ workers, said to number well in excess of 1,200. Beyond that, at Karlshagen, lay Community Barracks East, originally intended for the German military but made into a FZ-Arbeitslager (labour camp), for some 1,500 male prisoners employed by the air force, while a concentration camp cut from the forest farther south, at Trassenheide, kept thousands of slave labourers in appalling conditions. This was big business.
The first 350 rocket scientists and technicians began to move from Kummersdorf to Peenemünde in April 1937, although the facilities there were far from complete; indeed, the establishment did not reach full strength until 1940. Until then, the all-important engine development team, under Dr Walter Thiel, continued its work at Kummersdorf. Dr Thiel was born in 1910 and soon proved to be an outstanding scholar, excelling at all levels in his chosen subject, chemistry, summa cum laude, to gain his doctorate in 1934. The German Army Weapons Office was quick to spot his talents and Dornberger, then a major at Kummersdorf, recruited him into the Aggregate team. Ultimately it was Thiel who would be responsible for perfecting the engine which would take the much vaunted A4 (V2) rocket to London; he would not, however, live to see the dreadful results of his work.
In April 1937 Dornberger persuaded Rudolf Hermann, Hermann Kurzweg and Walter Haeussermann, the best aerodynamicists then available, to join his team, ready to make full use of the world’s most sophisticated, supersonic wind tunnel, then being built at Peenemünde. When complete, expected to be in late 1942, this would enable tests to be carried out at speeds of up to Mach 4.4 (4.4 times the speed of sound), importantly with an innovative desiccant system (moisture remover) to reduce the condensation misting caused by the use of liquid oxygen. Pending completion of the Peenemünde tunnel, Rudolf Hermann carried out initial tests on the A3’s design, in a small wind tunnel at Aachen Technical University. These tests suggested that the rocket could deviate from its intended flightpath in crosswinds, that the fins might burn up as the exhaust expanded in the lower air densities at height, and that, in any event, these fins were too small to control the rocket at high altitudes. Hermann Kurzweg thought likewise, having towed models of the A3 behind his car at 100km/h. Time would tell but, following satisfactory static tests at Kummersdorf, the A3 was ready for flight trials at the end of 1937.
With the necessary launch and test facilities yet to be completed at Peenemünde, the first four A3s were launched from Greifswalder Oie, where concrete launch pads and bunkers had been built for the purpose. On 4 December 1937, in appalling weather conditions, the first A3 lifted off successfully, but after a few seconds its recovery parachute deployed prematurely before burning off in the rocket’s plume, sending the rocket spinning into wind and crashing a short distance from the launch pad. This happened again to the second A3 a few days later, after which the parachutes were disabled for the remaining two firings – but again the rockets spun into wind and crashed. Exhaustive examinations concluded that the predictions from the early wind tunnel tests had been correct, that the rocket did indeed veer off the intended track in crosswinds, beyond the capability of the Kreiselgeräte guidance and control system to correct. As a result of these failures, work on the A3 was abandoned and the Aggregate team gave its full attention to the A4 and A5.
With Wernher von Braun as technical director, Walter Thiel as his deputy and engine expert, and Dornberger responsible for research, the rocket programmes at Peenemünde now developed apace in the technical design, guidance, aeroballistics, test, wind tunnel and manufacturing departments. Dornberger’s ambitions knew few bounds, beginning with the establishment of Gruppe IV (Group IV), within Wa Pruf 11, to plan and construct the facilities required then and in the future, with a little added everywhere as contingencies against unforeseen circumstances – and indeed dramatic events were now unfolding elsewhere in a turbulent Germany, which might threaten progress at the HVP.
Germany in the 1930s was never without its political intrigue, as the Nazi party overthrew the Weimar parliamentary democracy, increased its power generally and dominated the military, defying traditions, and ousting those in its hierarchy who did not display absolute and unequivocal loyalty to the Führer, Adolf Hitler. All Jews were removed from authoritative positions, the trades unions were disbanded and a new organisation, the Deutsche Arbeitsfront (DAF), the German Labour Front, began to flex its muscles. The majority of the new leaders were neither politicians nor businessmen, industrialists, scientists, engineers or technocrats, many being pseudo-intellectuals, such as Himmler, anti-intellectuals like Martin Bormann, and they were supported by an army of self-serving gauleiters (petty officials). From 1933 government economic ‘centralisation’ became the name of the game, largely to the detriment of commercial interests and fast-developing technologies, but military expansion, as a whole, was given a high priority.
Transition to the new order was far from smooth, with allegations of human frailties often used to weed out those seen to be disloyal or simply weak links, one such victim being General Werner von Fritsch, Oberkommando des Heeres (OKH), C-in-C of the Army, who had given his full support to the work at Kummersdorf in 1936, and the concept of a more extensive rocket development site at Peenemünde. He was forced to resign in February 1938, on suspicions of homosexuality, to be replaced as head of the OKH, by Generalfeldmarschall ( Field Marshal) Walther von Brauchitsch. Hitler disbanded the War Ministry and created the Oberkommando der Wehrmacht (OKW), the Armed Forces High Command, to be headed by Field Marshal Wilhelm Keitel, and it was he who would preside over massive growth in military assets, at a critical point in the development of the rocket for war. Having followed the rocketeers’ early progress, Fritsch and Brauchitsch had visited Kummersdorf in 1936 where they had pledged their support and the necessary funds. As artillery officers they were attracted to new weapons which could outrange contemporary guns, might deliver a greater punch, be more mobile and provide an alternative to the Luftwaffe’s bombers, over which they had no direct control.
One of the first actions taken by von Brauchitsch was to order the planning and construction of an A4 production plant at Peenemünde, to be controlled by a subsection of Wa Prüf 11, set up by Dornberger in January 1939, with Herr G. Schubert, a senior army civil servant, at the helm. Notwithstanding this decision, Fertigungshalle-1 ‘F-1’ (Mass Production Plant No.1) would not be completed until mid-1943, mainly because of Hitler’s continued indecision over the priority and funding to be accorded to the work being carried out at Peenemünde.
Dornberger was all too aware that the future of the A4, intended to become the rocket with which Germany could bombard London, needed the full support of the Nazi Party and Hitler himself. Accordingly, on 23 March 1939, he invited the Führer, his deputy, Rudolf Hess, Chief of Staff Martin Bormann, von Brauchitsch and Army Ordnance Chief General Karl Becker, to a progress meeting at Kummersdorf. He had prepared himself well, to capitalise on Hitler’s enthusiasm for innovative new weapons with which to prosecute his wars, as he described the research in hand, progress achieved with the A3 (referring to cutaway models of the missile), future concepts and technologies, stressing the potential for expediting rocket development, before the group toured the facilities and witnessed engine tests. He assured the Führer that the A4 would be constructed largely of steel, rather than the aluminium so urgently needed for aircraft and that the missile could, given the right priority, be operational by 1942. He was, however, surprised and disappointed by Hitler’s lack of penetrating questions and indeed his apparent disinterest in the rocket’s likely contribution as a weapon of war, concluding that there was more work to be done to convince him.
Blackboard ‘jottings’ by Wernher von Braun, believed to have been rescued from Peenemünde. (Author, Courtesy la Coupole)
Despite some sections still not fully operational, the Peenemünde facility was declared operational at the end of 1939, with Colonel Leo Zanssen in command. Having invaded Poland in September, Germany was now at war with France and Britain, and had fully mobilised its manpower. The armed forces and every section of industry were now demanding priority in their share of the men and materials available, but there was no clear system for allocating priorities in an already failing four-year economic plan, and this did not bode well for the rocket men. However, Dornberger, knowing that he had the support of von Brauchitsch, hoped that he would press for the HVP to be given enough resources for the missile assembly facility, and for rocket development to be ‘pushed forward by all possible means’, as being ‘particularly urgent for national defence’. Be that as it may, Hitler, Keitel and Hermann Göring, the Commander-in-Chief of the Luftwaffe, chose to give priority to those activities of immediate importance to the war. There was, however, some encouragement in May 1941, when Hitler changed his mind again, giving the rocketeers more – but still not enough to achieve the then delivery target of eighteen A4s by September 1941. The long term effects of this indecisive, stop/go programme would turn out to be very significant in the final stages of the war.
Before the A4 missile materialised, the A5 rocket, a diminutive version measuring 20 feet long and 3 feet in diameter, was introduced as a test vehicle. Aerodynamically identical to the A4, the A5 incorporated many of its components; it included an inertial guidance control designed by Siemens, a radio-command system to enable the engine to cut off from the ground and a recovery by parachute to be initiated, and an engine which ran on a similar alcohol/liquid oxygen mix. Multiple wind-tunnel tests had resulted in small, streamlined tail surfaces. The rocket was designed to manoeuvre into a ballistic attitude when the gyroscopes tilted in the desired direction of flight, causing the autopilot to send signals to the servos attached to the exhaust vanes, which would then deflect the blast to tilt the rocket over, while correcting any drift caused by crosswinds. The all-important gyros were designed to control the tilt during the curved flight path and apply course corrections as required. Pending delivery of the final gyro-autopilot system, the firm of Siemens installed an interim control fit. The A5 trials would provide data on ballistic shape, transonic behaviour, and guidance throughout the burning portion of the rocket’s flight.
Rheinbote. Long-range rocket gun. (Author Courtesy HTM Peenemünde)
At this stage the aim was to produce ten A5s a month and the first airborne ‘drop test’ models were delivered to Peenemünde in spring 1938, but it would be more than a year before they were cleared for airborne release. In September 1939 a Heinkel He-111 dropped an A5 from 20,000 feet, to achieve supersonic speeds at 3,000 feet, the stabilising fins keeping the dummy missiles within 5 degrees of the vertical, before the retarding parachute slowed the descent for them to ‘splash down’ safely – for post-flight examination. Ground launches followed at Greifswalder Oie, the first two without the stabilising system or recovery parachutes, merely to test the pre-set trajectories. The next two climbed vertically until their motors shut down at 45 seconds and momentum carried them above 30,000 feet before a signal from the ground deployed their parachutes, for them to splash down and be recovered, close to Oie. In the next test, the all-important guidance system performed faultlessly, to great applause from the ground. This A5 was seen to follow the programmed trajectory, tilt perfectly on time, then take up an easterly heading and level out as required, before the parachute brought the rocket down safely. The Siemens’ system continued to come up to expectations in the many more tests which followed, reaching heights in excess of 40,000 feet and ranges of eleven miles, the results confirming the theoretical calculations and predictions for the A4, thus vindicating the use of the A5 as a test vehicle for the ultimate weapon. Dornberger was euphoric, allegedly heard to say, ‘Now I can see our goal clearly, and the way that leads to it’, predicting that production of the A4 could be underway by 1943 – but that would prove to be a little too optimistic.
Attempts to increase the range of the A4 rocket, by attaching ‘wings’ to create the A4b, failed, and trials were abandoned after one unsuccessful launch. (Author, Courtesy HTM Peenemünde)
“Meanwhile, the Luftwaffe was beginning to show interest in work being conducted by civilian firms on a flying bomb, and by the end of the 1930s their collective efforts were being co-ordinated at Peenemünde West. The idea for a pulse-jet engine had been explored first by the Russian Victor Karavodine in 1906, then by the Frenchman George Marconnet in 1910. However, it was Paul Schmidt’s ‘Schmidt Duct’ engine which, in 1933, caught the attention of the German Air Ministry and, by the end of the decade, Fritz Gosslau of the Argus Engine Company, and Robert Lusser of the Fieseler Aircraft Company, were ready to offer their design for a relatively simple flying bomb.
The concept was based on a small, pilotless aircraft, driven by a cheap but powerful version of the Argus As-014, pulse-jet engine, in which airflow forced through shutters at the mouth of a tube into a combustion chamber would be mixed with a standard petrol fuel spray and ignited. This would cause an explosion which closed the front shutters, forcing the expanding air out through the jet pipe at the rear to provide the thrust. As soon as the pressure in the tube dropped, the shutters would open again, and this cycle repeated many times a minute, emitting a pulsating rhythm. The airframe would have a wingspan of about seventeen feet, on a fuselage some twenty-five-feet long, with the pulse-jet mounted above a conventional tail assembly. With the strong airflow needed for the engine to operate effectively, a powerful steam-driven catapult was needed to drive the little aircraft up an inclined ramp, aligned with its target, giving it enough flying speed for the pulse-jet to take over. When sufficient data had been collected to confirm a viable concept, Argus and Fieseler went to the German Air Ministry with firm proposals on 28 April 1942. Their confidence would be well rewarded.
Schematic outline of the Fi 103 (V1) flying bomb. (Author’s Collection)
For those at Peenemünde, it was now vital that their twin projects, the rocket and the flying bomb, be seen to be moving inexorably towards operational status and this, in a politically charged Germany, bred strange bedfellows. Typically, Reichsführer-SS Himmler, the head of the much feared Schutzstaffel (SS), in seeking to extend his influence, began to take an interest in developments at the HVP in 1940, awarding Wernher von Braun the honorary rank of untersturmführer (lieutenant) in the SS, this simple action attracting the attention and positive interest among other Germany leaders and industrialists.
While Aggregate rockets and the flying bomb were stealing the limelight, other German weapon interests were looking into the use of associated technologies. Rheinmetall-Borsig AG (RMB) had been invited to submit ideas for a rocket-assisted take-off (RATO) unit to expedite the take-off of large cargo aircraft now being produced, while German anti-aircraft gunners were looking into the practicability of using rockets for air defence, possibly adapting the Wasserfall variant of the A4 to that end. Meanwhile, field gunners, on the lookout for long-range, lightweight and fully mobile supplements to their heavy artillery, were evaluating a relatively simple, long-range, four-stage, solid-fuelled rocket, christened Rheinbote. More ambitious was the Hochdruckpumpe (High Pressure Pump), a massive, static, multi-barrel cannon, primarily for the bombardment of London from sites in the Pas de Calais. All these ventures are outlined in Chapter Nine
For Germany the 1930s were years of extraordinary technological innovation, which brought great advances in rocket science for military applications and the use of space. By their dogged persistence, Dornberger, von Braun, Thiel and others laid the foundations for the new weapons of war, but now they faced rigorous test programmes before they could be deployed operationally.