The extent of the delays became apparent only after the first missiles reached the test stands. The initial static-test model, “Injection Aggregate 1,” was hand-built in Peenemünde’s workshops and then moved to Test Stand V in October 1940 for completion. It remained there for the entire first half of 1941. Welding problems and inexperience were part of the problem, but the basic difficulty was creating a reliable and workable system of valves, controls, and switches for the engine assembly. If the eighteen-pot engine was a “plumber’s nightmare,” the brand-new steam generator–turbopump system that moved the propellants from the tanks to the injectors was no less so. (The A-5 still used nitrogen gas pressurization to empty the tanks.) Unless care was taken in the design and installation process, fires and explosions could be triggered in any number of ways, for example, by leaky lines or by propellants reaching the combustion chamber before ignition in the wrong quantities and with the wrong timing. Riedel’s design bureau, working with Thiel’s propulsion group, created at least two valve systems and tried them on Injection Aggregate 1 and its successors by running the fuels through without igniting them. Not until the summer of 1941 were the second and third static-test A-4s finished, and only in late September was the engine actually fired on the first one.44
Those difficulties were harbingers of worse to come. On October 21 at the A-4 launch site (Test Stand VII) and on November 5 at the engine test stand (I), two missiles exploded. The first caused significant damage to the facilities; two days after the second, Dornberger sent a blistering and revealing memorandum to Peenemünde. He called the leading managers of the center “irresponsible” for leaving “young, inexperienced test engineers with the leadership of tests” on new rockets, especially “in the present life-and-death situation for HVP [Peenemünde-East].” He demanded that von Braun, Thiel, or “Papa” Riedel be present for the first thirty experiments on each vehicle. He reproached them as well for traveling the country trying to arrange mass-production contracts singlehandedly, for indulging in “futuristic dreams,” and for engaging in endless negotiations with the Air Ministry over the Interceptor and anti-aircraft missiles. Until the air force had made up its mind as to what it wanted and supplied the manpower needed, “these totally useless meetings over future hopes will cease and you gentlemen will alone concentrate on the development of the A-4.”45
Dornberger was annoyed about more than the Luftwaffe discussions. The summer and fall of 1941 was the apogee of planning at Peenemünde for the A-9/A-10 ICBM and, on the margins, for even more exotic possibilities like a manned A-9 and the employment of atomic reactors for rocket propulsion. A small contract to study the latter possibility was given in 1942 to the Research Institute of the Reich Post Ministry, notwithstanding Dornberger’s admonition. Those dreams did not divert many resources from the main task, but they were in line with the character of Wernher von Braun, who, in the words of Dornberger, “reveled in any project that promised to be on a gigantic scale, and, usually, in the distant future. I had to brake him back to hard facts and the everyday.”46
From late 1941 until late 1942, Dornberger had to do a lot of “braking” in order to concentrate all of the energies of von Braun and his group on the A-4, its production, and the most important follow-on projects. Only six days after his fiery memorandum, Dornberger sent another to Peenemünde, indicating that he had had an argument with von Braun about whether the A-8 or the A-9 should be the next missile. The chief of Wa Prüf 11 ordered a concentration on the A-8, because he felt that developing its nitric acid-oil propulsion system was more feasible than building the glider missile. Much was uncertain about the A-9’s aerodynamics and guidance, yet the leading Peenemünde engineers seemed to prefer the A-9 because it was a more interesting problem. But Dornberger could not make his order stick; some A-9 research continued, as did the design of the A-7, an A-5 with wings that was to serve as a test vehicle for the glider missile concept.47
Just before Christmas Dornberger sent another memorandum to the leadership of Peenemünde, this time appealing for the concentration of all efforts on launching the first A-4 by the end of February 1942. He also lectured them on the slowness with which scarce materials were being eliminated from various components of the production version. Ever since the audience with Hitler and the mass production planning of the fall, that problem had become urgent because of the severe shortages of many metals, especially aluminum. Dornberger’s demand for a quick changeover, however, was rather unreasonable. The task facing von Braun’s engineers—making the A-4 fly, even though its exotic technology was suffering from innumerable and inevitable “childhood diseases”—was daunting enough without the redesign in steel of critical components like the engine and the turbopump. For anything that came into contact with super-cold liquid oxygen, the change proved extremely difficult because of the brittleness of steel at cryogenic temperatures. Imposing that challenge on top of the one of creating a mass produced ballistic missile threatened to make the design process chaotic.48
The seriousness of Peenemünde’s technological and organizational difficulties that winter is revealed by yet another furious memo, penned by Dornberger on February 5. This time his outburst was caused by an accident with the first flight vehicle, “Launch Aggregate 1” (later called “Test Model 1” or V1), while it was suspended for an engine firing on Test Stand I. After being fully tanked, the missile slipped out of its “corset,” fell 2 meters, smashed three fins, and came to rest on the rim of the engine nozzle. At fault was a design oversight that had all the hallmarks of inexperience: The corset was not able to bear the full weight of the fueled vehicle after the liquid oxygen’s temperature caused shrinkage of the fuselage. Dornberger was enraged that such an apparently stupid mistake had been made, delaying the first launch by a few more weeks. He reminded his subordinates about the absolute political necessity of showing some practical results. He also ranted against what he saw as their Raketenflugplatz mentality, “i.e., the propagandistic exploitation of an idea only to receive money and priorities, while not even building a usable test device practicable for eventual mass production.” It was hardly a fair charge; of the thousands of engineers and craftsmen at Peenemünde, only about a dozen came from the old rocket groups.49
Most interesting, however, is his discussion of the problems with the A-4 design and testing process, made even more fascinating by the responses of Thiel, who neatly scribbled pungent marginal comments on his copy. First, Dornberger was annoyed by the interminable stay of missiles on the test stands, which he felt revealed a deeper problem:
The whole design has apparently been done as if hundreds of people had the time to spend weeks going all over the rocket on the test stand, installing valves, doing assembly work, moving cables, and generally fumbling around. Cooperation between the Test group and the TB [“Papa” Riedel’s design bureau] is lacking…
He accused the engineers of forgetting the demands of simplicity and ease of access that would be necessary for mass production and field use; instead the missile was a “flying laboratory.”50
Thiel’s marginalia confirm that he indeed had serious conflicts with Riedel. His comment on the above quote was: “The TB fights tooth and nail against any influence from Tr [Propulsion] or Vers [Test].” On an earlier page, Thiel asked why the test stands should take the blame for the “garbage” produced by the design bureau and the shops. But the propulsion chief also noted that there was a contradiction between Dornberger’s demands for results in the shortest possible time and his demands for a well-planned, fully developed vehicle.51