Everything Rocket Propelled

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Max Valier was probably the greatest promoter of rocket flight and space travel of the first three decades of the twentieth century. He was a tireless lecturer and writer whose articles were translated and reprinted all over the world. But some of his methods for promoting rockets did not sit well with his colleagues. They considered some of his "experiments" to be little more than publicity stunts.

Max Valier

To show that rockets were reliable and powerful enough to use in transportation, Valier built rocket-powered cars and rocket-powered sleds in the 1920s.

For example, Valier created a series of solid-fuel rocket-powered automobiles that tore around German racetracks at breakneck speeds, spewing huge clouds of smoke behind them. He also built rocket-propelled railroad cars and even a rocket-propelled ice sled. No practical use existed for such things. They were, as his colleagues thought, publicity stunts. But they served two purposes: getting the public to talk about rockets and

To show that rockets were reliable and powerful enough to use in transportation, Valier built rocket-powered cars and rocket-powered sleds in the 1920s.

Rocket Propelled Cars

Valier's rocket-boosted glider was flown by Friedrich Stamer on June 11, 1928. It was the first rocket-powered aircraft to fly. The experiment was funded by Fritz von Opel, a wealthy German car manufacturer. Later, Opel sponsored a second rocket-powered glider, the Opel-Sander Rak 1 (above). Piloted this time by Opel himself, it made a successful flight in 1929 but was badly damaged on landing.

showing that rockets were powerful enough and reliable enough to propel a manned vehicle.

Yet, one of Valier's experiments was important in the history of space travel. He designed and built the first rocket-propelled aircraft, which flew on June 11, 1928. It was an early, primitive ancestor of the Bell X-1—which was the first aircraft to break the sound barrier—the X-15, and the space shuttle.

The VfR immediately started publishing a journal called Das Rakete (The Rocket). Meanwhile, many of its members, including Max Valier, were busy giving public lectures. They were also writing articles for popular magazines.

VfR Ambitions

While educating the public about the possibilities of rockets in space travel, the VfR continued its ambition to build and launch a real liquid-fuel rocket. The members were convinced that if they could only accomplish that, some wealthy business would give them the money to build a full-sized spaceship. Because of Robert Goddard's secrecy, no one in Europe knew that he had already built and launched such a rocket. European experimenters were instead inspired by Oberth's book. It laid out all the advantages and problems of the liquid-fuel rocket in convincing mathematical detail.

Meanwhile, Johannes Winkler had gone off on his own. Employed by the Junkers aircraft company, he had been working on solid-fuel rockets to aid the takeoff of heavy aircraft. He had also privately designed a high-altitude meteorological rocket. It was intended to be propelled by a liquid-fuel motor. Backed by some private sponsors, he began work on the small liquid-fuel motor.

Winkler tested this motor on what he called a "flying test stand," which resembled a box kite. On February 21, 1931, the test stand rose to an altitude of about 30 feet (9 m). Recovered undamaged, it was launched again on March 14. This time it traveled 180 feet (55 m) high and crash-landed 570 feet (174 m) away from where it took off. This was the first flight of a liquid-fuel rocket in Europe.

The VfR was at first a little miffed that Winkler had accomplished this on his own, without informing the society of his plans. But its members were tremendously encouraged. Winkler had proven

In 1931 Johannes Winkler built and flew the first European liquid-fuel rocket. This photograph shows Winkler standing with his rocket. The motor is the small cylinder at the top center of the rocket. The three large cylinders contained fuel, oxygen, and nitrogen (for pressurizing the tanks).

that the liquid-fuel rocket was possible.

Some of the more active members of the VfR—Rudolf Nebel, Klaus Reidel, and Wernher von Braun—had already been working on their own liquid-fuel rocket. They called it Mirak (for "minimum rocket"). Nebel had convinced the owners of an abandoned ammunition storage facility near Berlin to allow its free use as an experimental station. The 300 acres (122 hectares) of land containing buildings, bunkers, and blockhouses was perfect for their needs. Nebel and his colleagues posted a sign reading Raketenflugplatz Berlin (Berlin Rocket Flight Station) and went to work.

Nebel's immediate team included Reidel and von Braun. A separate group of buildings was run by Winkler and his assistant, Rolf Engel. Willy Ley, vice president of the VfR, used his skills as a writer to record and publicize the work. Good press was important because the experimenters had much more enthusiasm than money. They depended a great deal on Nebel's ability to talk just about anyone into giving them materials and services. The nearly

penniless scientists even needed contributions of food.

The initial task was to develop a reliable liquid-fuel rocket motor. The main problem was that liquid fuels produced a great amount of heat. This tended to melt the combustion chambers and nozzles. No metals or alloys were available that could withstand such intense heat and pressure.

The obvious solution was to circulate water around the motor. This is the same way that the engine in an automobile is cooled. In 1931 the first test of the new water-cooled motor was initiated. It was successful, producing a thrust of 40 pounds (18 kg). On May 14, two months after Winkler's success, Nebel's team launched their

Eighteen-year-old Wernher von Braun (right) carries a Mirak rocket to its VfR launchpad outside the city of Berlin in 1930.

Wernher Von Braun German Uniform

completed rocket Mirak III. It soared to a height of more than 60 feet (18 m). Willy Ley described the flight:

The rocket took off with a wild roar. [It then] hit the roof of the building and raced up slantwise at an angle of about 70 degrees. After 2 seconds or so, it began to loop the loop, rose some more, spilled all the water out of the cooling jacket, and came down in a power dive. While it was diving, the wall of the combustion chamber—being no longer cooled—gave way in one place, and with two jets twirling it, the thing went completely crazy. [Amazingly enough, it] did not crash because the fuel happened to run out just as it pulled out of a power dive near the ground. Actually, it almost made a landing.

In spite of its wild flight, the rocket was almost undamaged. This pleased its makers immensely. Their next rocket, the Repulsor II (Mirak III was counted as Repulsor I), was even more successful. It rose to about the same height as Mirak III but traveled about 1,800 feet (549 m) horizontally. It had none of the spectacular aerobatics of the earlier rocket. Equipped with a parachute so that it could be recovered undamaged, the rocket went on to make several more successful flights. It achieved altitudes of 1,000 and 1,500 feet (305 and 457 m). Willy Ley enthusiastically reported these triumphs to the press. Soon they attracted the attention of the German military.

The Treaty of Versailles, signed at the end of World War I (1914-1918), prevented the German army from developing long-range artillery. The Ordnance Department saw rockets as a possible way to get around this restriction. In the spring of 1932, it sent three inspectors to the Raketenflugplatz. They were Captain Dr. Walter Dornberger, who was in charge of solid-fuel military rocket development; Colonel Dr. Karl Becker, chief of ballistics and ammunition; and Captain D'Aubigny von Engelbrunner von Horstig, Becker's assistant.

Working with the Army

Becker had a lifelong interest in rocketry. His interest went back to 1929 when, as a student, he helped write a textbook on ballistics. The book contained a long section on rockets. It included a description of Robert Goddard's 1919 paper and Oberth's spaceships.

When first assigned the task of developing a liquid-fuel rocket for the German army, Becker was shocked that almost no one in Germany was doing any work on them. Discovering serious experimenters was not easy. "At that time," Dornberger recalled, "rocketry was a sphere of activity beset with humbugs, charlatans and scientific cranks, and sparsely populated with men of real ability." Becker and Dornberger were not terribly impressed by the VfR's rockets. Yet, they were very much impressed by the men creating them—especially the brilliant young engineer Wernher von Braun.

The army agreed to pay VfR to develop an improved version of its rocket. The members received 1,360 marks—about $340 in modern money. In July 1932, the new rocket was tested at the army artillery range at Kummelsdorf, Germany, 60 miles (97 km) south of Berlin. The rocket reached an impressive altitude of 3,300 feet (1,006 m), but most of its flight was horizontal. It crashed about 2 miles (3.2 km) away, before its parachute could open.

Becker told Nebel that while he was unimpressed, the army was still interested in rocket development. But they had no intention of putting more money into it. Not only would the VfR have to continue its experiments on its own, Becker said, it would have to do so in secrecy. This was impossible, Nebel argued. It was only through publicity that the VfR was able to raise the money it needed. Becker replied that the army would fund further research, but all of the work would have to be done behind the guarded fence of an army base. Nebel did not like the idea of working under these conditions and refused.

Not all of the VfR rocketeers turned down Becker's offer, however. Wernher von Braun, for example, accepted an army research grant. He realized that the VfR, with its limited facilities and even less money, would never be able to develop the kind of sophisticated rocket he envisioned.

Looking back from the vantage point of the twenty-first century, it is easy to fault von Braun's decision. It ultimately led to the V-2 rocket that was so destructive in World War II. However, when the young engineer accepted the army's offer, German dictator Adolf Hitler had not yet taken power. Von Braun's acceptance was no different from that of any scientists or engineers accepting grants from their armed forces.

Wernher von Braun holds a model of the V-2 rocket he helped design in the early 1940s.

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When twenty-year-old Wernher ¡1^

Kummelsdorf to begin his research on developing a long-range military rocket, he could not have been too impressed with the facilities. They were little better than what the penniless VfR had been working in. His "office" consisted of half a concrete bunker with a sliding roof. The other half was devoted to solid-fuel rocket research.

In spite of the poor conditions, von Braun and his assistant built a small, water-cooled rocket motor by January 1933. Fueled by alcohol and liquid oxygen, it produced an astonishing 310 pounds (141 kg) of thrust for a full sixty seconds. Six months later, von Braun had a motor that was more than twice as powerful.

This motor, instead of being cooled by being encased in a water jacket, was cooled by its own fuel. This technique, called regenerative cooling, first passes the fuel through the hollow wall of the combustion chamber. In doing so, the fuel not only carries away the heat but becomes preheated itself in the process. This motor was a great improvement. It was not only much lighter than a water-cooled motor, but the

Before World War II, the work of U.S. rocket scientist Robert Goddard (top) paralleled that of German engineers. After the war began, Goddard was only allowed to work on rocket-assisted takeoffs (middle) while Germany developed the huge V-2 rocket (bottom).

A liquid-fuel rocket combines

a fuel and an oxidizer in a

combustion chamber where

they are burned. The result

ing hot gases shoot out the

nozzle. The reaction to this

escaping gas causes the

rocket to move in the oppo

site direction. Liquid fuels

burn at very high tempera

tures that would melt the

combustion chamber and

nozzle, so most liquid-fuel

engines circulate the oxidizer

or fuel through the motor

walls first. This not only

helps cool the motor, it pre

heats the fuel, making the

rocket work more efficiently.

preheated fuel burned much more efficiently. Dornberger thought it was time to start building a rocket that flies.

The first attempt at a predecessor of the V-2 rocket, the A-i, failed at launch. Rather than try again, an entirely new rocket was designed. Two A-2s were tested a few days before Christmas 1934. They achieved an altitude of 1.5 miles (2.4 km). The flight of the rockets was perfectly vertical, with none of the aerobatics of the VfR rockets.

Soon other ex-VfR engineers and scientists began joining the Kummelsdorf team. An even bigger rocket, the A-3, appeared on the drawing boards. At 22 feet (6.7 m) long, it was the biggest liquid-fuel rocket they had ever tried to build. It would be propelled by a powerful alcohol-liquid oxygen engine. This would produce 3,200 pounds

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