Michael Neufeld - The Rocket and the Reich

Once again Himmler’s attempt to take over the Army rocket program had failed, but the whole affair certainly had an intimidating effect. For von Braun, however, it proved to be one of the most fortunate things that ever happened to him in the Third Reich. After the war his defenders were able to credit him with an anti-Nazi record that he never had. Moreover, the nominal grounds for the arrest fitted perfectly with the image that he and his group wanted to project in the United States, especially after Sputnik. Von Braun’s “team” were, so the mythology later ran, apolitical space enthusiasts from the Weimar rocket groups who were forced to make a detour through military development in order to reach the stars. It is certainly true that spaceflight played a role in the thinking of Peenemünde; von Braun and a few close friends toyed with the idea in their spare time, and Dornberger used it to promote the élan of the group as the founders of a radical new technology. The evidence also indicates that von Braun expressed real regret during the war that the rocket had to be developed first through military funding, a statement that was risky, as the arrests proved. But he was an opportunist who had no overriding moral qualms about building missiles for the Third Reich, even when slave labor became involved; the same goes for almost everyone else at Peenemünde, insofar as they had any choice in the matter, which most of them did not. As for the spaceflight origins of the group, the center’s engineering leadership had been largely recruited or drafted after 1938 and had little or no previous exposure to rocketry. The motivations of those later recruits ranged from avoiding the Eastern Front to working in a technically exciting field to making a contribution to the war effort. Spaceflight was not central to their concerns, even if they later became fascinated by it. 49

Although the arrests of von Braun, his brother, and his collaborators would later be used as evidence that they were just apolitical or anti-Nazi engineers punished for their enthusiasm for spaceflight, Himmler in fact had orchestrated the affair in order to strike back at von Braun and to install the SS as the supreme power in the rocket program. For the moment Himmler’s ambitions had again been frustrated by the Army and Speer, but within a few months new opportunities would present themselves. In the meantime the Army rocket group had to continue wrestling with two difficult challenges: manufacturing and deploying a balky A-4 and completing the development of Wasserfall.

The start of A-4 manufacturing in the Mittelwerk had by no means signaled the end of the ballistic missile’s production and reliability problems, as the political troubles of March indicated. In fact, a whole new set of difficulties had cropped up once A-4 launches began in Poland in November 1943. Of the eight Peenemünde-built missiles launched from Heidelager by early December, only one had successfully reached the target area, and it had broken up during the last phase of reentry into the atmosphere. That “airburst” phenomenon was dismissed as a consequence of rough transport conditions breaking screws on the fuselage structure, but it was actually the first hint of a technical problem that would plague Peenemünde for the next year. At the same time the production of both missiles and ground equipment remained stuck in a morass of difficulties that once again delayed deployment for months. The A-4 was still too technically immature to be a reliable weapons system. 50

Among the nastiest problems found in Poland was a pattern of tail explosions and engine cutoffs shortly after launch. The missiles sometimes fell back on the mobile launch set, destroying hard to replace equipment and endangering the lives of the troops in training. Missiles also frequently went awry during launch because of components that were poorly made or were oversensitive to handling and transport in the field. By the spring of 1944, however, the launch problems had been mostly solved during tests at Blizna and at Peenemünde, which had begun firing again in late 1943. 51

It was the spontaneous breakup of up to 70 percent of the incoming missiles a few thousand meters over the target that remained particularly vexing. Prior to the RAF raid, all A-4s had been fired along the Baltic coast from Usedom; dye markers colored the sea where the missile impacted. There had been no obvious indication from those firings, or from the handful of A-4s that had strayed off course and hit land, that the missiles had not come down in one piece. In April, after five months of firing in Poland, the causes were still undetermined. Two reports, one by von Braun and one by an officer on Dornberger’s staff, noted that the possible theories included the overpressurization of the fuel or oxidizer tanks, the ignition of leftover propellants within the tanks, the loss of metal skin off the fuselage through to reentry heating and aerodynamic forces, or the loss of the tail fins due to the same causes, leading to disintegration of the missile. 52

It proved to be extremely difficult to find out what was going on. The telemetry system could send a only handful of measurements to the ground, a more advanced system was mired in development problems, and no telemetry was available at all in Heidelager. The fragments that fell to the ground were silent as to the cause. Visually observing the airbursts was exceedingly difficult, because the missiles arrived at a velocity of 2,400 kilometers per hour (1,500 mph), but desperation drove the rocket specialists to try to accomplish that feat anyway. Sometime in May or June 1944, Dornberger and von Braun set up camp at the very center of the target zone in Poland, on the theory that no missile was likely to be perfectly accurate. Peenemünde’s Technical Director “was only 300 feet [90 meters] from the impact of one live [armed] missile. I was standing in an open field and, knowing the accurate launching time from a warning sign displayed from an observation tower, I beheld the rocket coming out of the blue sky. I threw myself down… but a moment later a terrific explosion hurled me high into the air. I landed in a ditch and noted with some amazement that I… had not suffered as much as a scratch.” During those trials, Dornberger did witness one airburst through his binoculars. The warhead and instrument compartment came down in one piece, but what caused the disintegration of the main body remained as obscure as ever. In June Peenemünde began vertical launches from the Greifswalder Oie, so that the missiles could be tracked and visually observed on reentry. Those launches sent A-4s as high as 176 kilometers (109 miles) into space, but observations again proved inconclusive. 53

In the absence of definitive evidence and under heavy political pressure to produce results, the rocket group tried many solutions. An October 1944 report, based on dozens of launches in Poland, listed eleven measures that had no statistically significant effect on the rate of airbursts, eight that appeared to make matters worse, and ten that had a positive outcome. Yet the author could only draw preliminary conclusions as to the cause, in part because no solution produced dramatic results and in part because of the difficulty of sorting out causation when two or more measures were tried simultaneously. 54

Earlier in 1944 an excessive rise in the alcohol tank pressure had been the favorite explanation of von Braun’s group. As a result the tank ventilation system was modified. Eventually a number of missiles were launched in such a way as to exhaust the alcohol supply completely, which showed that this tank was not the culprit. Around June, General Rossmann suggested glass wool insulation between the tanks and the fuselage skin to prevent overheating of leftover propellants. That measure seemed to have a dramatic effect in the early firings and was incorporated into missiles intended for the front. Over a long run, however, glass wool did not make much of a difference. The best results were eventually obtained through the reinforcement of the center section of the A-4, in particular through the welding of a steel collar around the forward end. It appears that heat-weakened skin panels were torn off by aerodynamic forces close to the ground, leading to the breakup of the missile. Because all wind tunnel measurements and structural calculations seemed to rule out that explanation, it had been too long discarded in favor of an internal fault. 55