German Rocket Society - Verein für Raumschiffahrt by Frank H. Winter - Part 7

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The following paper is ©2015 Frank H. Winter.

Contents

Further Details On First Mirak

As described and depicted in Pendray's May 1931 article, the first Mirak was a nose-driven vehicle that featured Oberth's small Kegeldüse motor embedded in the center of the base of the liquid oxygen “reservoir” tank, with ogival head which held about one liter (approximately 33.5 fluid ounces) capacity. A safety (escape) valve was located internally, on top of the actual LOX tank and with the head of the rocket. The long, tubular fuel (gasoline) tank was attached under one side of the base of the LOX tank, like a side-mounted tail, while an ordinary small, hand-held carbon dioxide cylinder of the type used for making soda water served as a “charger” for forcing in the fuel into the combustion chamber. The gasoline fuel amounted to about half a liter (about 16.75 fluid ounces). Both propellant tanks were of duralumin, a trade name for a hardened aluminum alloy developed by the Dürener Metallwerke Aktien Gesellschaft that happened to be one of the donors of this material to the Society. The combustion chamber wasof heavy copper alloy.

The Pendray article, Ley's accounts in his Rockets, Missiles, and the published Jelnina and Rhorwild paper provide fuller descriptions of how the first Mirak worked and how it was fired, but it suffices in this summary to say that it weighed about three kg (about 6.5 lbs.) when fully loaded and in firing tests “against a spring balance apparatus,” according to Pendray, it produced a “lift” (today, known as “thrust”) of 4.5 kg., or almost ten lbs. As a result of their work on the first Mirak, Nebel and Riedel were issued a joint German Patent, No. 633,667 of 13 June 1931, for a “Recoil Motor for Driving Liquid Substances.” However, the design was very simple and in fact despite Nebel's own high praises about it, the basic design was remarkably reminiscent of Oberth's Kegeldüse, except the chamber was spherical rather than conical.[1]

Drawing, first Mirak type rocket motor of the VfR. Artist, unknown.
Drawing, first Mirak type rocket motor of the VfR. Artist, unknown.

The Second Mirak

Due to a number of cooling, propellant circulations, and other problems encountered in working on the first Mirak, an improved second Mirak was built. The overall configuration remained about the same but attention was paid to changing the combustion chamber to produce better flow of the combustion gases. The second Mirak was also slightly larger. Pendray incorrectly said it now consisted of a steel jacket with “a lining of ceramic material made especially for the experiment(s) by a company in Berlin. It was thought that the ceramic lining would resist the heat...The chamber itself was cylindrical in shape...”

But years later, Ley explained that since Pendray did not understand German and his (Ley's) English was “very poor” at the time on Pendray's visit, there was a misunderstanding. What Ley had meant to say was that one of the (original) specimens of the Kegeldüse “had been tested with a ceramic liner” but the lining cracked, with one piece blocking the nozzle, “causing the combustion chamber to explode.” Also, Ley makes it clear this “happened before the first Mirak existed even on paper (i.e. in 1929, during the “Frau im Mond” period.”) In any case, Jelnina and Rhorwild say that the motor for the second Mirak was likewise of heavy copper alloy and thus weighed more and generated considerably greater thrust. But the rocket exploded about April of 1931.[2]

Drawing, second Mirak type rocket motor of the VfR. Artist, unknown.
Drawing, second Mirak type rocket motor of the VfR. Artist, unknown.

The Third Mirak And Earliest Tests With The First Big Test Stand

At about this juncture, further developmental work on the motors was begun on the premises of the Raketenflugplatz. Many changes resulted in the design and construction of the basic rocket, the most important of which was an altogether different motor. One of the test motors is considered by Jelnina and Rohrwild to have been an “intermediate stage,” although few technical details are known. It is generally referred to as the Mirak III, but also called “the egg” motor by Ley. (Pendray quite rightly said it was actually “cylindrical, with each end finished off in a hemisphere.”)

Drawing, third Mirak type rocket motor of the VfR. Artist, unknown.
Drawing, third Mirak type rocket motor of the VfR. Artist, unknown.

But in its final form the Mirak III motor was designated the 160/32 motor which meant it consumed 160 grams (5.6 oz.) of LOX and gasoline per second and produced a thrust of about 32 kgs (70 lbs.) for about ten seconds. However, there were actually variations of this motor (and even a model with a different designation) and hence several performance and other figures are offered by Jelnina and Rhorwild. Pendray, in his article says the third Mirak “was nearly complete three weeks ago” (i.e. in mid-April when he was in Germany). The latter statement is also important as it shows the test he saw was not the third Mirak but the Mirak II motor. (Incidentally, the VfR's consumption/thrust designations were also very useful in calculating exhaust velocities for these motors.)[3]

Pendray's article further provides invaluable detailed information (not found in German sources) on the construction and general layout of the “proving stand,” or test stand, at the Raketenflugplatz. One notable feature, for example, was a fixed “clockwork device with a revolving drum of smoked paper and a needle fastened to the moveable rod.” When a test was made the drum was made to revolve by its clockwork. “The amount of lift (i.e. thrust) of the motor,” Pendray continued, “is accurately recorded on the drum, which can be later taken off, the curve calibrated, and the behavior (performance characteristics) of each motor studied and preserved for comparison.”

Hence, performance records were definitely taken, even from these earliest years although none are known to have survived, other than a typical VfR “thrust diagram” that was reproduced in print in two or more of Ley's later articles. On the other hand, Ley says that “At the Raketenflugplatz the only measurements which were actually made were of the thrust and the duration of burning.” In any case, as already indicated, this kind of information was not conveyed widely, to the VfR membership in any of the Society's Mitteilungen or other known VfR publications. Perhaps, however, as explored further below, the real problem is that these kinds of records were simply not permanently kept at the time and this was probably a serious if not acknowledged internal management problem. Von Braun himself, later admitted in his “Reminiscences” that what he and other Raketenflugplatz members showed the German Army officers when they came visiting were “meager diagrams and data as we could lay before them.”

Here, it is important to note that Ley claims “the Kegeldüse was Oberth's invention and the first Mirak was Nebel's (although possibly with help from Riedel), but after that almost any device or development was the result of informal talks and conferences between three or four or even five of six people. We never paid any attention to the question of who had thought of what...If the question of who invented the standard motor were important, I'd be inclined to give most of the credit to (Klaus) Riedel.”[4]

The rocket motor of the third Mirak benefited greatly from the hard-learned experiences of the previous Miraks and more closely resembles more modern internal configurations especially in the better placement of the propellant inlets, except that the exhaust nozzle was quite long and the outside featured unusual horizontal “cooling ribs,” as they are called by Jelnina and Rohrwild, around the middle and similar ribs arcing over the top. However, water-cooling was also commonly used during this period.

Yet the Society's mechanized, automatic recorded thrust measurements were quite sophisticated in their day and were never matched by the American Interplanetary Society that later became the American Rocket Society. There is no wonder Pendray was so excited in witnessing a test and vividly describes what that was like. Moreover, it is also seen that a huge advantage that the German Society had over the American one was a “permanent” test site; during its own testing years, the AIS/ARS could only test their rockets (and later make static tests) in vacant fields, with a single portable test stand hauled on a special cart by an automobile.[5]

Among other marked changes in the motor was that the propellants were pressure-fed by gaseous nitrogen rather than carbon dioxide and this was found to be “more dependable and steady,” according to Pendray. Pendray observed that the Mirak III rocket was “somewhat heavier than the earlier Miraks” and “was expected to weigh, loaded with fuel (i.e. propellants), about four kilograms (8.8 lbs.),” although it carried about the same amount of propellants. Yet Pendray adds that the Mirak III rocket was “expected to fire 32-seconds, using four times as much (liquid) oxygen by volume.” That is, the engineers found they could better control the propellant consumption and combustion duration through nitrogen pressurization and a safety valve. The motor was built of Duralumin with an inner lining of copper. Jelnina and Rhorwild give the (standard) thrust at about eight kg (17.6 lbs.) for about 20 seconds and “possibly (up to) ten kg (22 lbs.)...”[6]

However, not much attention was paid to the “exact flare” of the combustion chamber nozzle, even though Pendray reported that Guido von Pirquet in Vienna had made elaborate calculations on the ideal measurements. But in practice, the Raketenflugplatz experimenters found that the flare “varies for each fuel and fuel mixture...”[7]

It seems, Pendray had visited at the right time because the static testing at the Raketenflugplatz had only started a month before, on 12 March 1931, on the so-called “Large Proving Stand” that utilized the heavy angle-iron launching rack built for the Oberth rocket. The valves were operated by an intricate arrangement of cables “thin wire ropes,” (according to Ley) and pulleys, the overall firing system described at some length by Ley in both his book, Rockets, Missiles and on pages 60-61 and 63 of part two of his article “The End of the Rocket Society”, appearing in Astounding Science Fiction for September 1943. (The latter also describes the VfR's “Portable Stand.”) Jelnina and Rohrwild also use these sources for their own lengthy description of the arrangement and operation of the stand. (Ley says he had originally written articles “for German engineering journals” at the time this was going on, but does not cite these journals and later re-wrote his accounts from memory.)

Ley also spoke about accidents, including explosions, happening during the earliest period of experimentation with the stand (“just enough explosions to keep us from getting foolhardy”); but the experimenters soon became very proficient with safety precautions and “such accidents were rare.”

Still, the noise of the testing could be heard for some distance away and because of this and the then, bizarre nature and aims of the Society, the group were called “the fools from Tegel,” that gave rise to the book title of Nebel's autobiography, Die Narren von Tegel (The Fools from Tegel). Ley also mentions the sequence of firing orders shouted by the observer, “Feuer! - Benzin! - Sauerstoff!” (“Fire! - Gasoline! - Oxygen!”) (At “Fire!,” an electric switch was closed that ignited a small black powder tube that served as the igniter for the liquid-propellant test motor, then when the flame was well established across the mouth of the exhaust nozzle, gasoline was carefully injected, followed by the LOX.

The earliest known "countdown" for a space launch, albeit a fictional one, has been credited to the British writer George Griffith (1857-1906) appearing in his short story "The Great Crellin Comet" published in "Pearson's Weekly Christmas Annual" (London) in November 1897; however, this was a countdown for a huge gun aimed toward space to avert a comet heading to Earth. The earliest known countdown for a rocket, also fictional, was introduced in the 1929 film “Frau im Mond,” for dramatic effect before heading into space. But perhaps a form of the now standard countdown for a true rocket was most likely first used at the huge German Army rocket development site of Peenemünde [technically, Peenemünde-East] from the 1930s, or earlier, at the German Army test site of Kummersdorf. It is not known if the American Robert H. Goddard used such a practice even earlier.)[8]

Switch To Alcohol As Fuel And The First Regenerative Cooling Efforts

Sänger and Engel credit Riedel for thinking, in the winter of 1931, of “using a water-alcohol mixture which Oberth had proposed” (in his Die Rakete zu den Planetenräumen of 1923). Gasoline had been used up until then (and unknown to the VfR people at the time, also by Goddard as well) since this fuel was very readily available and cheap. Alcohol offered two main advantages: a higher exhaust velocity and helping cool the combustion. Prior to the actual substitution, alcohol and water combinations were studied and a 25% alcohol/75% water mixture is mentioned in early notes by Ley, cited by Jelnina and Rohrwild, although other percentages came to be used in practice; then, it was finally found that the ideal ratio is 60% alcohol and 40% water.

“Experimental motors” in a “Portable Proving Stand” were used for these alcohol/LOX propellant tests in which the stand was fitted with a special scale for measuring thrusts. Sänger and Engel also say that the preliminary tests with gasoline (for comparison sake) and with alcohol-water mixtures were carried out from August 1932 to March 1933. Initially in these tests, cooling was done by “static water cooling.” Later, by December 1932, another great technological improvement was made; regenerative cooling was introduced. But before we take up the conclusion of the VfR's work with both alcohol/LOX and finally, with regeneratively-cooled systems (with larger motors), we first need to briefly cover a new series of rockets and their rocket motors, known as the Repulsors.[9]

The Repulsors And The VfR's First Flight Rockets

The first Miraks were strictly evolutionary stationary test (and “demonstration”) motors and never flew. The small group of VfR experimenters had reached a logical point where a basic flight model was needed and they began discussing possible arrangements. But as described by Ley, Klaus Riedel took it upon himself to devise and build one based upon a standard Mirak III motor. This was a “nose-drive” configuration, favored at this time, with the motor on top. (The motor was immersed in a water jacket for cooling, while the whole was nested within a cylindrical container with an overhanging conical covering on top.) The remainder of the rocket was suspended on each side by the angled oxygen and pressurized gas fuel-feed lines, respectively, protruding from the middle of each side of the motor/cooling container. Connected to the ends of these two lines were two long pipes, or “legs,” one on each side, and the bottom of the legs were mounted to a double hoop arrangement, to which were mounted four simple hemispherical fins.

Thus, Riedel's primary practical solutions for the basic flight rocket consisted of: (1), placing both the pressurized nitrogen-feed and fuel (gasoline) systems within one pipe, or “leg,” instead of the previous two in the Mirak design; and (2), placing the oxidizer (LOX) in the second leg, thereby dispensing with the aluminum tank on the top in the previous arrangement in the Mirak. And since this was a basic flight test rocket, it was an open arrangement with no body covering or fairing. (No mention is made in the available descriptions of the means of ignition of this rocket.) Riedel flew it at the Raketenflugplatz on 10 March 1931 up to a height of about 60 ft. (18) before it “fell down and broke a leg,” according to Riedel (i.e. damaged one of the pipes.)

One-stick Repulsor motor on display Udvar-Hazy Center
One-stick Repulsor motor on display Udvar-Hazy Center

Soon after, the rocket was repaired, and a second and “first planned,” although more erratic, flight was made on 14 May in which the rocket climbed up to an estimated maximum altitude of 200 ft. (60 m.). (Ley goes into this flight in more detail in his “The End of the Rocket Society,” part two.) At this point, the experimenters decided the rocket required its own name since it was different from the Mirak. Ley chose the name Repulsor, after the space vehicle in Kurd Lasswitz's novel, Auf Zwei Planeten (On Two Planets), of 1897. It also became known as the Repulsor No. 1, or the “Zweistab-Repulsor” (“Two-Stick Repulsor”) because it was followed by others. “Thus, wrote Sänger and Engel, “two months after Winkler's rocket had been launched, a second launch of a liquid (propellant) rocket in Europe took place...”[10]

Pendray was informed by mail from Ley on the first and later Repulsor flights and he duly summarized these in a follow-up report presented to the American Interplanetary Society on 13 November, then published, with sketches, in the Society's Bulletin for December 1931. Again, Pendray's report constitutes one of the better contemporary accounts of progress of the VfR at their Raketenflugplatz, apart from the later accounts from memory by Ley. Up to June 1931, three similar models of the “Two-Stick Repulsor” were launched, the later models featuring a parachute for safe recovery of the rockets activated by a time fuse and also two, rather than one motor.

Altogether, according to Ley, the VfR developed these rockets up to the Repulsor No. 4. Their flights, noted Pendray, “have been followed with cameras and other devices for determining their speed and height, though...they have not themselves carried any instruments.” (Again, records - including photos - were made of the performances of the VfR's rockets, now including their first flight rockets; however, these records evidently no longer exist, except for a very few photos.) Then, in August 1931, the first launch was made of the much improved “Einstab-Repulsor” (“One-Stick Repulsor”) model that was actually Repulsor No. 4. That same month, in a special article in the Bulletin of The American Interplanetary Society, Pendray had already gone into some detail (provided by Ley at the time) on “the most successful shot of all” of these Repulsors, up to 1.5 km (0.9 mi). (In his later writings, Ley offered a slightly different figure of “about one km,” or 0.6 m.) Jelena and Rohrwild find that there were about four or five Two-Stick and three or four One-Stick Repulsors. Yet, Pendray added that the rockets were “often in an extremely erratic course” and that “an enormous amount of work must still be done to solve the problem of stability and steering in flight.”[11]

Pendray concluded his December 1931 article by stating: “As a result of these successful experiments the German engineers have announced that they are now building a rocket of the one-stick Repulsor type which they believe will be able to reach an altitude of about 25 miles (40 km). This rocket will have three motors, each about 18 in. (45.7 cm) in total length, including the nozzle. The first motor is already finished, and on the first trial in the proving stand it developed a lift (thrust) of about 140 lbs. (63.5 kg). Slight changes in the fuel mixture and fuel inlets are being made.” After the changes, the thrust was expected to increase to 180 lbs. (8.6 kg), so that three motors would produce 540 lbs. (245 kg).[12]

Pendray probably did not know it at the time he wrote those words, but the supposed 140 lb. (63.5 lb.) motor had actually started its separate development in April 1931 from the “egg,” or Mirak III motor mentioned above, then later evolved into a much bigger motor of 140 lbs. thrust that Ley named the “Aepyornis Egg,” because of its similarity to the huge prehistoric Aepyornis “elephant bird” egg that had been discovered in Madagascar in 1930. Moreover, Ley says this motor “was expected to yield...140 lbs.” but “actually it barely made 50 kg (110 lb.)...” Hence, there were still occasional “misinterpretations, “ by Pendray, and no doubt by others, in regard to developments by the VfR during these years.[13]

However, what is more important in this separate development is, as pointed out by Sänger and Engel, that static (i.e. water) cooling had been applied and “was not found sufficient for these much bigger engines” (than the regular Mirak series and later Repulsor flight vehicles). Therefore, “The decision was made to develop an engine for 250-750 kg (550-1,653 lb.) of thrust with regenerative cooling, using fuel as (the) coolant.” Part of this thinking was also linked to Riedel (and Ley's) consideration by the winter of 1931 of switching to alcohol as a fuel.

(It was also in December 1931 that retired Army Major Hans-Wolf von Dickhuth-Harrach assumed the presidency of the VfR since Oberth was fully occupied and out of the country for some time and, as mentioned, he had resigned anyway and for some months the Society had been technically leaderless. Von Dickhuth-Harrach's address, at Berlin-Wilmersdorf, Schoelerpark 2, thus became a sort of new downtown Berlin VfR headquarters although clearly all the activities of the Society were at the Raketenflugplatz. Since his youth, von Dickhuth-Harrach had developed deep interests in astronomy, aviation, technology of all kinds, and other topics, and later acquired a flying license, besides pursuing a military career. He became especially interested in space flight upon reading Oberth's 1923 classic work on the subject that also led him to write articles on the subject, including a chapter “On the Philosophy of the Space Travel Problem, Fundamentals, Realizations, and Phantasms” in Werner Brügel's anthology, Männer der Rakete, or Men of the Rocket, that would appear in 1933.) [14]

Decline Of The VfR And Hiring Of von Braun By The Army

Despite the remarkable progress that had been made and the now more ambitious plans on the part of the VfR, the following year of 1932 opened as an extremely difficult one for Germany due to political tensions and worsening “economic misery,” in the words of Ley. “It was a winter,” he added, “during which the roster of VfR members shrank to less than 300, most of them deprived of their livelihood...At the Raketenflugplatz, the men struggled along.” Hückel made it known he could no longer donate any money and Ley was forced to go on the lecture circuit to raise funds. By the end of the year, the other VfR generous benefactor, Dipl. Ing. Wilhelm Dilthey had likewise suddenly stopped supporting the VfR - but as reported in Raketenflug for December 1932, in this case it turned out that his body was found “deep in an abyss” in the snows of Kaisergebirge mountain some six months after he had been killed in an accident there on 28 February 1932 from “a solitary walk in the snow.” He was so dedicated to the cause of spaceflight that in his will he left the VfR the sum of RM 500. “His death was one of the worst blows that have long affected us,” reads the report in the Society's Raketenflug. “We have lost a man of rare decisiveness and initiative.”

Mostly during this year, Riedel reorganized the testing equipment at the Raketenflugplatz. It had also been later in 1931 (during the filming of Tonwoche newsreel No. 60) that one of the Repulsors had crashed into the nearby police barracks that naturally led to a visit to the Raketenflugplatz by the police chief and consequently led, on 17 October, to certain restrictions and partial curtailment of launches. The newsreel, Ley commented later, “was virtually the last triumph of the VfR, (and) everything after that was (a) rapid decline.” Understandably, for all of these reasons, we have sparse information on the testing or other progress made in 1932 by the VfR. In particular, we hear nothing about further work on the “Aepyornis Egg” motor and it is very likely it was indeed, halted.[15]

Sänger and Engel further observe that “during 1932, the crew (of the Raketenflugplatz) began to disperse.” Most notably, young (now 20 years old) Wernher von Braun had left; he had been hired by the German Army, the contract issued on 27 November. Von Braun had not been able to participate in much of the Mirak and Repulsor developments, simply because at least from April to July 1931 he had been attending courses at the Eidgenössische Technische Hochchule (the Federal Institute of Technology) in Zurich, Switzerland, towards his Bachelor's degree in Mechanical Engineering although on the other hand there does exist a lengthy, single-space, two-part paper by von Braun titled (as translated into English), “Theoretical Preliminary Investigation on a Working Rocket Engine Injector ('Suction Nozzle'),” dated from Zurich, 26 May 1931, in the Willy Ley papers. Now whether this study, including formulas’, was used in the VfR's Mirak or other rocket motor developments we do not know. For certain, he remained an entirely enthusiastic and valued member of the VfR.

Shortly before he left, during the Society's General Meeting of 24 September 1932 von Braun had been elected as a member (the youngest and only student or “Student Engineer”) on the VfR Board of Directors, although Ley later recalled that soon after this appointment he “became less accessible.” But Ley, writing in his 1944 book, Rockets - The Future of Travel Beyond the Stratosphere, says that Wernher von Braun resigned from this post not long after he had been selected for the Board. Von Braun was to eventually graduate from the Technische Hochschule Berlin (Technical Institute of Berlin) in the spring of 1932 earning a bachelor's degree. At the same General Meeting, von Dickhuth-Harrach was re-elected President; Ley retained his position as Vice-President; Riedel was named the “Technical Chief” of the Raketenflugplatz; while Engineers Hugo A. Hückel and Wurm were made Board members. [16]

As early as October 1931, von Braun says he witnessed “the first public demonstration of Mirak 1” (actually, a Repulsor) at the Raketenflugplatz, and later saw a Repulsor in flight in August 1932, while on vacation from school, besides participating in VfR affairs as much as he could despite his busy schooling schedules; sometimes, he would even deliver lectures to visitors at the site and stay either overnight or on weekends. He had already authored an eleven-page primer for the use of the experimenters, dated 28 February 1932 with his own calculations on performance, trajectories, and tank and parachute sizes.

He had also published small articles on rockets in newspapers during this period and perhaps his first published magazine article, “Das Geheimnis der Flüssigsrakete” (“The Secret of the Liquid Rocket”) appeared in Germany's leading popular science magazine Die Umschau (The Review) for 4 June 1932. It is very general in nature although does depict the old Oberth rocket “descending” by parachute (i.e., a doctored photo) and another touched-up photo of the main test stand at the Raketenflugplatz with the caption reading: “In a heavy iron frame, which serves as a launcher, all the important data of a new rocket motor, as recoil exhaust velocity, etc., is determined. The wire cable is used for opening the valves from a distance. In the foreground (is) a Dewar bottle with liquid oxygen.”[17]

But one example of von Braun's connection to the German army occurred in the spring of 1932 when a “black sedan” with three men dressed in civilian clothes visited the Raketenflugplatz to witness a test of a then new and large “three-liter: (0.7 gallon) Repulsor. These men were later identified as Col. Karl Becker and his subordinates, Captains Walter Dornberger and Ernst von Hortsig, all from the Army Ordnance's Ballistics and Munitions section. Von Braun was present but Nebel remembered that these men had already visited before, earlier in 1932 and in the previous year.

Becker had actually secretly donated 5,000 RM in 1930, through Nebel, to help support the rocket development work of the VfR - to see how far they could go and to try to learn from them. However, Neufeld finds that by May 1931, according to a memo from Becker, he had become disillusioned with Nebel as to his “value” and potential use to the Army's own secret rocket program which had begun in 1929 with solid-propellant rockets although was now beginning to focus on liquid-propellant developments. Neufeld adds that Becker was put off by Nebel's free-wheeling style, his “sensationalistic articles,” and dubious technical claims. Dornberger as well decried Nebel's showmanship.

Ley says further that Nebel's “Confidential Memo on Long-Range Rocket Artillery” sent to Becker was wholly inadequate. (Ley called it “the worst nonsense that was ever written.”) Nonetheless, the “rocket fad” from the late 1920s had already aroused interest by the Army, principally by Becker, in the potential of the rocket, especially the liquid-propellant type, as a long-range weapon. It is usually inferred in the literature that this interest was spurred by the fact that the rocket was not covered in the Versailles Treaty imposed by the Allied powers after the close of World War I that had severely restricted the build-up of arms programs by Germany. But there was a secret arms build-up anyway from 1928, despite the Treaty.

Then on 3 March 1932, Nebel had offered to demonstrate a rocket launch and successful parachute recovery to the Army at the Army's expense. Becker agreed, at the requested rate of 1,367 RM (then about $ 325), if the rocket was successful. Consequently, at 4 a.m. on 22 June 1932, in secrecy and without the knowledge of the VfR's Board of Directors, Nebel, Riedel, von Braun, and an un-named Raketenflugplatz mechanic, took a four meter (13-ft) long one-stick Repulsor and launch rack by car to the Army's artillery test range at Kummersdorf, about 17 mi (27.3 km) south of Berlin, where the visitors admired “a formidable array of phototheodolites, ballistic cameras and chronographs - instruments of whose very existence we had theretofore been unaware,” recalled von Braun.

The rocket flew up to 600 m (1,968 ft.) (although Dornberger says 100 ft., or 30 m) then eventually crash-landed 1.3 km (0.8 mi) away; it was therefore a “great disappointment,” in his words, that the performance was far from the 3.5 km (2 mi) altitude promised by Nebel. If anything was gained from this experience, it was that it confirmed to Becker to concentrate the Army's own rocket developments on in-house development; by the same token, the VfR and their much publicized Raketenflugplatz were to play no part in these future developments.[18]

Nebel continued to visit the Army's Ordnance offices in Berlin to see what more could be done, but to no avail so far as his own interests were concerned. However, Dornberger later recalled, he had “been struck during my casual visits to Reinickendorf by the energy and shrewdness....and by his (von Braun's) astonishing theoretical knowledge.” On the other hand, Dornberger (and his other Ordnance colleagues) were exasperated that for all their efforts, the Raketenflugplatz personnel were very lax in keeping records. “It was not, for instance,” he later wrote in his book V-2, “possible before the middle of 1932 to obtain from the Raketenflugplatz in Berlin any sort of records showing performances and fuel consumption during experiments.” Neufeld largely characterizes the VfR experimenters as undertaking their developments through pragmatic experience rather than through systematic technology development.[19]

Consequently, as a result of their various visits to the Raketenflugplatz including observations and talks, von Braun was placed under a secret contract with the Army, in which he would not only initially serve on Dornberger's “specialist staff,” but could complete his education towards a doctorate; moreover, the research for his thesis, “Konstruktive, theoretische und experimentalle Beiträge zu dem Problem der Flüssigkeitsrakete” (“The structural, theoretical and experimental contributions to the problem of the liquid rocket"), was to be carried out at the Kummersdorf facility, although for secrecy's sake it was not identified at all in the thesis. (Also, as part of this arrangement, even before he became an Army employee, von Braun undertook the research at Kummersdorf under a stipend of 300 Reichmarks per month. Then, according to Neufeld, even before completing his degree, he officially began employment with the Army on 1 December 1932. This thesis was finally defended in June 1934, earning the 22-year old von Braun a doctorate from the University of Berlin.

As for von Braun's outlook at the time of the Army's offer, much has been written. But in one of his recollections, he said: “I had no illusions whatsoever as to the tremendous amount of money necessary to convert the liquid-fuel rocket from the...Mirak...to a serious machine that could blaze the trail for the space ship of the future...To me, the Army's money was the only hope for big progress toward space travel...”[20]Continue to Part Eight

Chapter 1, Chapter 2, Chapter 3, Chapter 4, Chapter 5, Chapter 6


Footnotes

  1. ^  Pendray, “The German Rockets,” p. 6; Ley, Missiles, Rockets, pp. 140-141, 154; Nebel, Die Narren, pp. 103-105.
  2. ^  Pendray, “The German Rockets,” p. 7; Ley, Missiles, Rockets, pp. 140-141; Jelnina and Rohrwild, p. 41.
  3. ^  Ley, Missiles, Rockets, p. 142; Jelnina and Rohrwild, pp. 41-44; Pendray, “The German Rockets,” pp. 5, 11.
  4. ^  Pendray, “The German Rockets,” p. 9; von Braun, “Reminiscences,” p. 129; Ley, Rockets, Missiles, p. 200. The “thrust diagram” of apparently the large 0.32/64 motor with a thrust up to about 60 kg (132 lb.) was published, for example, in Ley's articles, “The Story of European Rocketry,” p. 9; “Some Practical Aspects of Rocket Engineering,” Aviation, Vol. 35, November 1936, p. 19; and, “Rocket Propulsion - A Résumé of Theory with an Account of the Practical Experiments made to Date,” Aircraft Engineering, Vol. VII, September 1935, p. 228. These same sources should also be consulted, particularly the latter, pp. 227-231, with extensive bibliography, for Ley's more technical descriptions of the VfR's rockets, and experiments involved. See also, (Willy Ley), “Die Versuch des `Veriens für Raumschiffahrt e.V.,'” in Brügel, Männer der Rakete, pp. 120-134, with photos. It is most interesting to compare the level of rocket testing technology with that of the American Interplanetary Society/American Rocket Society (ARS) of the period, even though the ARS continued their experimental work up to 1941, about seven years after the VfR had ceased to exist. Ley, who witnessed and participated in among the ARS's first static tests in 1935, makes some of these comparisons in his Aircraft Engineering article just cited. Consult also, Frank H. Winter, “Rocket History through an Artifact: American Rocket Society (ARS) Test Stand No. 2 (1938–1942,” paper presented at Forty-Fourth History Symposium of the International Academy of Astronautics, 27 September–1 October, 2010, Prague, Czech Republic, paper IAC-10-E4.3.02, to be published in 2014 by Univelt, Inc.
  5. ^  Ley, Missiles, Rockets, p. 142.
  6. ^  Pendray, “The German Rockets,” pp. 11-12; Jelnina and Rohrwild, pp. 41-42.
  7. ^  Pendray, “The German Rockets,” p. 12.
  8. ^  Mitteilungen, March 1930, p. 3; Jelnina and Rohrwild, p. 43; Ley, Missiles, Rockets, pp. 143-145; Willy Ley, “The End of the Rocket Society,” Astounding Science Fiction, Vol. 31, August 1943, pp. 64-78, and Vol. 32, September 1943, pp. 58-75; Jelnina and Rohrwild, pp. 42-44. (Afterword by Robert Godwin, re the earliest known "countdown" for a space launch), George Griffith, The World Peril of 1910 (Apogee Science Fiction: Burlington, Ontario, Canada 2006.) pp 268-269.
  9. ^  Jelnina and Rohrwild, pp. 44, 53; Sänger and Engel, p. 225.
  10. ^  Ley, Missiles, Rockets, p. 147; Sänger and Engel, pp. 221-222, 224-225; Ley, “The End of the Rocket Society (– Part 2),” pp. 60-61, 64. Sänger and Engel also mentioned the alleged launch on 10 April 1929 of a liquid-propellant rocket by Friedrich Sander, then a repeated flight on 12 April, to more than 2,000 m (6,560 ft), but this has never been verified and it may never have happened.
  11. ^  G. Edward Pendray, “Recent Worldwide Advances in Rocketry,” Bulletin, The American Interplanetary Society, No. 14, December 1931, pp. 1-6; Ley, Missiles, Rockets, pp. 148-150; G. Edward Pendray, “The German `Repulsor' Makes 1 1/2 Kilometer Vertical Flight,” Bulletin, The American Interplanetary Society, No. 11, August 1931, pp. 2-3; Jelena and Rohrwild, p. 49.
  12. ^  Pendray, “Recent Worldwide,” p. 6.
  13. ^  Ley, Missiles, Rockets, p. 151.
  14. ^  Sänger and Engel, p. 225; Hans-Wolf von Dickhuth-Harrach, “Saubers Wirtschaft,” Raketentechnik, 1 November 1933, p. 1; “Herr Major a.D. Hanns-Wolf von Dickhuth-Harrach, Berlin,” Weltraum (Cologne), 1 Jahrg., December 1939, p. 51; Werner Brügel, ed., Männer der Rakete (Hachmeister & Thal: Leipzig, (1933).
  15. ^  Ley, Missiles, Rockets, p. 152; Neufeld, Von Braun, p. 47; “Dipl. Ing. Wilhelm Dilthey,” p. 7; Ley, “The End of the Rocket Society (– Part 2),” p. 70.
  16. ^  Sänger and Engel, p. 225; Neufeld, Von Braun, pp. 45-47, 57-58; Willy Ley, typed draft of article, “Around European Rocketry,” item II, in the G. Edward Pendray Papers, Seeley Mudd Library, Princeton University, Princeton, N.J., Box 4, folder 12; Ley, Rockets - The Future, p. 151; Wernher von Braun, “Theoretische Voruntersuchung zu einem nach dem Injektorprinzip arbeitenden Raketenmotor ('Saugdüse'),” Zürich, 26 May 1931, in Willy Ley papers, NASM. There are also numerous letters from Ley to Pendray in the Pendray papers that provide considerably more details on the then, on-going work at the Raketenflugplatz on their rockets although permission is required for their use. Again, the purpose of the present treatment to provide an overall history of the Society including summations of its technical accomplishments.
  17. ^  Neufeld, Von Braun, pp. 44, 47-48; von Braun, “Reminiscences,” p. 128; Wernher von Braun, "Das Geheimnis der Flüssigkeitsrakete,” Die Umschau, Vol. 36, 4 June 1932, p. 450.
  18. ^  Neufeld, Von Braun, pp. 9, 49-50, 74, 97; Ley, Missiles, Rockets, p. 155; Ley, “The End of the Rocket Society (– Part 2),” p. 71.
  19. ^  Neufeld, Von Braun, p. 53; Walter R. Dornberger, V-2 (Bantam Book: New York, 1979), pp. 32-33; von Braun, “Reminiscences,” p. 129.
  20. ^  Neufeld, Von Braun, pp. 47, 54, 58, 561; Dornberger, pp. 21, 28; Michael B. Peterson, Missiles for the Fatherland - Peenemünde, National Socialism, and the V-2 Missile (Cambridge University Press; Cambridge, N.Y., 42, 51. See also, von Braun, “Reminiscences,” p. 130.
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