Figure 1.1 also shows a characteristic feature of the early German Army rockets. The engine was actually immersed in the alcohol tank, because it shortened the rocket and helped to cool the engine when the combustion chamber was so long. Difficulties in getting proper atomization and evaporation of the propellant droplets had driven von Braun and his co-workers toward longer and longer combustion chambers to give the propellant mixture more time to burn completely.73 Incomplete burning was one of the main causes of suboptimum engine performance. The 300-kg-thrust engine had an exhaust velocity of about 1,500 meters per second, whereas the theoretical maximum for a 75-percent-alcohol/liquid-oxygen rocket is a little over 2,000 m/sec at the combustion chamber pressures then feasible—10 to 13 atmospheres. In the equation of the rocket, exhaust velocity is one of the absolutely critical values determining performance; the higher it is, the more efficient the engine. For comparison purposes, the most efficient rocket engine in use today, the Space Shuttle Main Engine, has an exhaust velocity of around 4,500 m/sec using liquid hydrogen and liquid oxygen at a combustion chamber pressure of about 200 atmospheres.
All the problems with the A-1 and the redesign they necessitated meant many delays to the schedule of the program. At the time that von Braun completed his dissertation in April 1934, the A-2 was still months away from being finished. There was nothing unusual about such technical setbacks. In the course of a year and a half, the young physics doctoral student and his few assistants had significantly outstripped the existing amateur rocket technology. The systematic approach imposed by Ordnance had much to do with their success, but von Braun’s brilliance was no doubt a factor as well. For his efforts, he received high honors from his dissertation committee, headed by Erich Schumann, when he defended it at the beginning of June 1934. The subject was so secret that even the title was classified. Von Braun’s diploma carried a phony title instead: “Regarding Combustion Experiments.”74
Steadily increasing resources were another crucial factor in the technological progress made at Kummersdorf. As small and inexpensive as the rocket program was in 1933–34, it benefited from the Nazis’ commitment to rearmament and from Becker’s rising star in that process. Becker cultivated close contacts with Hitler and the Army leadership. During or after Hitler’s visit to Kummersdorf in September 1933, the Führer promised Ordnance even more resources than it had hoped for. Schumann’s research branch was expanded to a Section of Testing Division and pursued some rocket research of its own. One of Schumann’s students, Kurt Wahmke, who had graduated before von Braun, was involved in experiments with hydrogen peroxide as an alternative oxidizer in the spring of 1934. During a careless experiment, Wahmke mixed the hydrogen peroxide with alcohol to see if he could produce a premixed single propellant. An explosion killed him and two assistants.75
At the end of 1934 the A-2s were finally ready. Two were shipped to the North Sea island of Borkum for launching; they were called “Max” and “Moritz” after the twins in the German version of the popular cartoon strip The Katzenjammer Kids. Secrecy, safety, or both must have motivated the choice of the island as a launch site. Von Braun, Riedel, and four others arrived on December 10, followed by Erich Schneider and by Leo Zanssen, who had joined Section 1 no later than mid-1933. Rudolph came with the liquid-oxygen tanker after finally clearing security checks and being hired. Dornberger was not able to attend because he had been rotated into the first solid-rocket artillery unit on October 1 and could not be released from duty. That was doubly unfortunate for him, because unguided 11-cm-diameter solid rockets were also to be tested on Borkum for their possible utility in anti-aircraft defense.76
On December 19 the 12-meter-high A-2 launch mast and all the measuring and photographic equipment were ready. Only the weather was uncooperative, with gale-force winds on a very cold North Sea day. Because the approaching Christmas holidays left little time for waiting, the first launch was carried out anyway. “Max” functioned perfectly. The engine burned for sixteen seconds, and the rocket reached about 1,700 meters in altitude before a wind gust produced precessions that tipped the vehicle right over. It was found buried in the beach sand 800 meters away. The next morning at dawn “Moritz” performed almost identically. It was a gratifying beginning.77
With the launch of the A-2s, the German Army liquid-fuel program had completed its first phase. From its uncertain beginnings as a minor activity on the margins of a powder rocket program, it had evolved into a successful research project that had produced flyable rockets more advanced than any so far built in Germany. As a result of the Nazi seizure of power, it had also been possible to impose the ultrasecrecy Army Ordnance had wanted, while capturing much of the talent that had grown up in the spaceflight movement and amateur rocket groups. Secrecy also laid the cornerstone for Army Ordnance’s “everything under one roof” philosophy of rocket research and development. The future was clear, if vague in details: It was feasible to build a large liquid-fuel ballistic missile with a range of hundreds of kilometers. But for that to become a reality, the state would have to invest vastly increased resources.
Chapter 2
The Founding of Peenemünde
In March 1935 the National Socialist regime publicly repudiated the Versailles Treaty, instituted conscription, and unveiled the existence of the Luftwaffe, which had been forming inside the Air Ministry. Adolf Hitler’s assumption that the Western powers were too indecisive to respond effectively was proved correct. Encouraged by that international climate and by the steady improvement of the German economy, Hitler began to accelerate rearmament in 1935–36. Army Ordnance’s budget for weapons research expanded rapidly, it being the development and procurement arm of the largest armed service.
The rocket program almost inevitably profited from the Army’s improving situation, but it also gained from the Luftwaffe’s spectacular growth in the mid-1930s. The air force’s commander-in-chief, Hermann Göring, had great political power as “the second man in the Reich,” and the Luftwaffe had high priority because of the need to overcome Germany’s backwardness in military aviation quickly. As a part of its search for the latest technology, the Luftwaffe began to take an interest in the rocket as a propulsion system for high-speed aircraft. Out of that interest arose an interservice rocket alliance and a revolutionary new center: Peenemünde.
If the Army Ordnance rocket group wished to justify large budget increases, however, it also had to produce results. The A-2 launches on Borkum were an important step toward a bigger and better-funded liquid-fuel rocket program. In mid-January 1935 the group presented films, slides, and lectures about the expedition for the benefit of Becker, von Horstig, Schumann, and other leaders in Ordnance, as well as representatives from the Navy and the Air Ministry. The reaction of at least one unnamed officer was so enthusiastic that Wernher von Braun had to respond to the idea of developing a scaled-up A-2 as a missile with a range of 50 kilometers.1