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“Development of the
V-2 Rocket, Part 2"
From Air Trails Magazine, March 1946

Editors Note: This article gives an in depth description of the development of the V-2 rocket, a German weapon of World War II. The historical significance is [sadly] dramatic but the technical significance still relevant. A derivative of the V-2 was used in the early 1990's by Iraq. Part 1 spoke of the early development of the German Rocket Society and its transition to Nazi weapons research. Parts 2 and 3 of this article represent a useful tutorial on rocket science.

This article is written by Willy Ley, a member of the 1930's German Rocket Society and gives us a first hand account of the history and technology behind rockets.

(continued from last week)....... A-3 was the first project of the Peenemünde institute,—founded with the backing of Field Marshal von Brauchitsch for the German army, to the accompaniment of the most profound disinterest of the Nazi party and, it is said, against the wishes of Hitler who failed to see any value in rocket research. The A-3. rocket was fully five times as heavy as its prototypes A-1 and A2, weighing, ready for take-off, 1,650 pounds. The rocket motor developed a thrust of twice the take-off weight or 3,300 pounds at sea level. The fuel supply lasted for forty-five seconds; the rocket stood twenty-five feet tall and had a largest diameter of 2 1/2 feet. Control was achieved by means of vanes operating in the exhaust jet; when they were set for a vertical course, the rocket attained an altitude of 40,000 feet. When fired at the famous ballistic angle for maximum range (45°), the rocket traveled eleven miles.

This was still hardly better than the performance of medium artillery, but a 1,650 pound rocket was still only a rather small rocket. Count von Braun insisted that the army go ahead. General Dornberger shared this point of view; von Brauchitsch provided the financial and priority backing and Colonel Kesselring (who was later the commander of the German forces in Northern Italy) called Prof. Oberth from the Mediash in Rumania in order to have the chief theorist of liquid fuel rockets on hand whenever his services should be required. Since Oberth’s name was rather well known through the activities of the not quite forgotten German Rocket Society, a screening job had to be provided for him,—the Rector magnificissimus of Berlin University obligingly provided Oberth with a chair for Physical Astronomy. It is doubtful whether he ever entered a Iecture hall there.

Sketch of the original rocket motor of the German Rocket Society.
This was later developed into the powerplant of the V-2.

At Peenemünde plants for a new and bigger rocket were drawn up. It was fernrakete A-4, (Long Distance Rocket, Aggregate No. 4). Using fuel pumps an idea of Oberth’s), A-4 could he built in a truly gigantic scale. Applying another idea of Oberth, (keeping thin-walled fuel tanks under interior pressure to prevent their collapse) A-4 could be built lightly. Using a model of a rocket motor originally developed by the German Rocket Society an unbelievable thrust could be produced.

Fernrakete A-4 was to be around fifteen meters long (the final model was about one meter shorter, or forty-six feet long ), with a largest diameter of five and a half feet. The big stabilizers were to measure some twelve feet across: the take-off weight was to be in the neighborhood of twelve tons; the fuel load around 20,000 pounds adn the weight of the bomb carried, one metric ton! The range of the rocket was estimated at 400 kilometers which is 250 miles. Actually about 220 miles is the highest figure that was ever observed.

The design of this rocket grew through the years 1938 and 1939. In 1940 it was actually built. After some not to important changes this rocket became the weapon which the German Ministry of Propaganda called Vergeltungswaffe Zwei, or V-2.

But, at first, Fernrakete A-4 was what the Germans call a Sorgenkind, a term which combines the meanings of our words problem child and puny child.

A-4 misbehaved amazingly and failed to grow up for a long time. The very first, fired on July 6, 1942, exploded three feet above the ground with such violence that it destroyed its testing site. The second exploded with equal violence, but at an altitude of about 16,000 feet. The third did the same but the fourth showed that A-4 was a promising development in spite of everything. In October, 1942. it covered a distance of 170 miles, The fifth also functioned well, except that it could not be found after having been fired.

Number 6 to number 18 constituted a broken series of thirteen bad failures. Some did not take off at all, some exploded, Some broke into two shortly after take-off and crashed. No. 19 functioned well—and a hundred more rockets were built. Most of them worked, but one out of every five broke up in mid-air and one failure was particularly unfortunate front the point of view of the experimenters. They had called a large number of army officers and party functionaries together to witness a demonstration—it is said that Himmler presided over the gathering—and the rocket, after staggering into the air for about 200 feet, tilted over and crashed.

In 1943 Count von Braun packed up the films of the experiments and went to see Hitler at his headquarters at the Eastern Front. By then Hitler was desparate enough to look even at rockets; they might furnish a way out. The films impressed him and he ordered mass production of Fernrakete A-4 which then became the V-2.

Then the Nazis indulged in an experiment peculiarly their own in design and execution. The SS evacuated the small Polish town of Blizna in order to put the V-2 testing station there. And the SS went to another small Polish town of about 1,000 inhabitants, Sarnaki. which is situated 150 miles due North of Blizna and surrounded it in a wide circle. While the inhabitants of Blizna had been evacuated, those of Sarnaki had to stay in their town because Sarnaki had been chosen as target city. The Nazi experimenters wanted to see what V-2s could do to a city living a more or less normal life.

Over a hundred V-2’s were fired at Sarnaki during the six weeks front May 15 to the end of June, 1943. Sarnaki turned out to be too small a target for rocket fire front 150 miles away. Not a single rocket ever hit the town directly; the one that came closest crashed some 300 yards away. A number of houses were destroyed by the concussion waves of the explosions of a ton of Amatol (a mixture of TNT and ammonium nitrate) in each warhead. But the toll of life was small—one old man was killed and one woman seriously injured.

Strangely enough the test shots gave the Nazis’ big secret away. When the RAF bombed Peenemünde, that target was mainly one of V-1 research, although the British did know through their agents (the are said to have had two right in the institute itself) that the Germans also experimented with gigantic rockets.

Wartime Peenemünde installations, Circle: two V-2s being readied for test.

But they did not know details until June, 1944, when a test rocket exploded many miles above Swedish territory. Two tons of fragments, most of them small, were collected over an area of square miles and pieced together by British experts; they then knew that the weapon which they had to expect was a forty-six foot rocket.

In fact, the diagram which the British had ready when the first V-2 crashed into a London suburb on September 8, 1944, contained all the essential features. Some detail has been filled in by W. G. A. Perring, a Fellow of the Royal Aeronautical Society during a lecture delivered in London November 1st, 1945.

.......(continued next week)