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Let's just start with the uncomfortable fact that the American space program would not be what it is today if it weren't for the contributions of a scientist who was a former Nazi. Wernher von Braun was an SS officer during World War 2 and lead a team of German scientists in developing the world's first long range ballistic missile, a military program aided in large part by slave labor and concentration camps, and yet less than two decades later von Braun was leading a team of NASA scientists in the design and development of the Saturn V Rocket, the vehicle that ultimately propelled more than a dozen Apollo astronauts to the moon. 

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Historians still debate whether he was an apolitical scientist who had no choice but to work for Hitler or a cunning opportunist who knowingly made a deal with the devil to pursue his research, but what we do know is that he was a rocket-science prodigy. Upon earning his Ph.D. in physics in 1934 at the age of 22, he joined the German army as a civilian employee. While younger than most of his colleagues, von Braun lead the team that began developing a long range ballistic missile.

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Borrowing heavily from the work of an American rocket-scientist, Robert Goddard, von Braun's team built a rocket called the A-4, later renamed the V-2 or vengeance weapon. The V-2 was essentially a larger version of the liquid fueled rockets built by Goddard, though von Braun made changes to the engines that dramatically increased their power. First, he used alcohol instead of gasoline as the main propellant along with liquid oxygen. But, the real power of his design came from two turbopumps, turbines that moved huge volumes of fuel into the combustion chamber at high speeds. These turbopumps could force 58 kg of alcohol and 72 kilograms of liquid oxygen into the combustion chamber every second, giving it a thrust of more than 25,000 kg, far more than Goddard had achieved.

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Using this technology, on October 3, 1942, von Braun's creation became the first man made object to reach the threshold of space, flying to an altitude of 80 km. The missile could travel more than 5,600 km per hour and carrying a 1,000 kg warhead. As military weapons go the V-2 was terrifying, but not always accurate. While the Germans launched 5,000 of the missiles toward Western Europe, only about 1,100 actually reached their targets. Still, the V-2 was believed to have killed nearly 3,000 people.

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Now there is at least some evidence to suggest that von Braun's sympathy for the Nazi cause only went so deep. For one thing, he was jailed briefly in 1944 after some Nazi spies infiltrated his program and began to suspect that he wasn't loyal enough. But more importantly for science, when the end of the war was in sight, von Braun was ordered to destroy all work related to the V-2, but instead he hid his documents in an abandoned mine and recovered them shortly before he and his team surrendered to the U.S. army.

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As part of a carefully orchestrated mission known as Operation Paperclip, von Braun and his team were sent to the U.S. where he demonstrated his weapon to the U.S Army in New Mexico. Later he was transferred to Huntsville, Alabama, and eventually became director of NASA's Marshall Space Flight Center. It was here that von Braun lead the team that developed the Saturn V Rocket, the most famous of all the rockets. While his V-2 rocket was a pretty nifty piece of machinery, the Saturn V was truly revolutionary.

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102 m tall and at lift off weighed more than a dozen 747s and as the world witnessed during the Apollo missions, the Saturn V was not only incredibly powerful, it divided the work of space flight into an elegant three-stage system. The first of it's three expendable stages produced 3.4 million kg of thrust, making it 130 times more powerful than the V-2. It had five separate F-1 engines designed by von Braun's team so that the outer four engines could move in order to control the direction of the rocket while the center engine just provided more thrust.

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After lifting the whole thing to about 68 km, the first stage would separate and the second stage would fire, carrying the spacecraft to the edge of orbit. Once there, the second stage would detach and a third stage pushed the craft into orbit and then toward the moon. Nearly half a century after they were first used, the five first stage engines that were designed by von Braun's team are still the most powerful single-chamber, liquid-fueled rocket engines ever made.

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As for von Braun, he went on to rise through the ranks of NASA and worked for aerospace companies, eventually being awarded the National Medal of Science not long before his death in 1977, but he never truly escaped his past. Whether you consider him a villain or a visionary or both, there's still no disputing his legacy. Von Braun turned the dreams of early twentieth century rocket-scientists into reality and he did it in less than three decades. 

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