On that July 20, back in 1969, streets were almost empty you could have launched a聽huo chien聽down most streets in America without hitting a single person. That鈥檚 because almost everyone was huddled around a television set waiting for Neil Armstrong to take his small step for man and a giant leap for mankind. So what is a聽huo chien? A Chinese 鈥渇ire arrow鈥� that was the prototype for every rocket that has ever flown, including the giant 363 foot tall Saturn 5 that propelled Armstrong, Michael Collins and Buzz Aldrin on their epic journey to the moon.
Although the origins of the fire arrows are somewhat shrouded in mystery, it is clear that by about 1000 AD the Chinese were experimenting with arrows fitted with bamboo tubes filled with gunpowder. The tube was sealed at the front, and when the gunpowder was ignited, the hot gases released escaped out the back and propelled the arrow towards the enemy. Eventually in 1678 Newton would explain the basic principle of rocket propulsion by his third law of motion: 鈥渇or every action, there is an equal but opposite reaction.鈥� As far as rocketry is concerned, 鈥渁ction鈥� refers to the hot gases escaping, and the 鈥渞eaction鈥� is the rocket moving in the opposite direction. Of course, you do not have to understand Newton鈥檚 laws to terrorize an enemy with rockets. As early as 1241 the Tatars used rockets against the Poles in the battle of Liegnitz, and both pirates and navies eventually used the incendiary capability of rockets to set fire to sailing vessels. By the late 1700s, rockets with metal tubes to hold the gunpowder had been developed in India, providing greater thrust and a range of over one mile. In the battle of Seringapatam in 1760 British colonial troops were defeated by a barrage of Indian rockets.聽
But the British learned their lesson, and under Colonel William Congreve, the art of solid propellant black powder rockets was to reach a high point in the early nineteenth century. These 鈥淐ongreve鈥� metal rockets varied in weight from 25 to 60 pounds, could be fitted with an explosive warhead, and had a range of up to 3 miles. They were used against the Americans in the war of 1812, including during an unsuccessful attempt to capture Fort McHenry which protected the Baltimore harbour. Francis Scott Key witnessed that attack and memorialized the Congreve 鈥渞ockets鈥� red glare鈥� in the words to the Star-Spangled Banner. William Congreve dreamed of designing bigger and better rockets, but he certainly did not dream of using them for space flight. But Konstantin Tsiolkovsky did! Looking up at the night sky in Moscow in 1873 he began to wonder if man could ever reach out towards the stars. Although mostly self-educated, he correctly suggested that a liquid fuel when burned with liquid oxygen would produce a greater velocity of exhaust gases than gunpowder and could conceivably launch a rocket into space. Tsiolkovsky envisioned manned space flight, complete with details such as retrofire rockets to slow the space ship鈥檚 re-entry through the earth鈥檚 atmosphere. He, however, was a theoretician and did not carry out any experiments. But Robert Goddard certainly did!
The American physicist had been attracted to the idea of space flight after reading Jules Verne鈥檚 classic science fiction novel, From the Earth to the Moon. Like Tsiolkovsky, Goddard concluded that liquid fuels were preferable in powering rockets and calculated that liquid hydrogen and liquid oxygen were the ideal fuel and oxidizer. By 1919, Goddard had produced a scientific paper on 鈥淎 Method of Reaching Extreme Altitudes,鈥� and even suggested that a rocket could be designed to reach the moon. This earned him ridicule from other scientists as the 鈥渕oon rocket man,鈥� who did not realize that a rocket engine could not operate in the vacuum of space. Goddard demonstrated in the laboratory that rocket engines most certainly would work in a vacuum, but bitten by the criticism, he became more secretive about his research. On March 16, 1926, Goddard made history by launching the world鈥檚 first liquid-fueled rocket. The liquid oxygen-kerosene vehicle only rose to a height of 184 feet, but the launch marked the beginning of the Space Age.
Rocketry had also captivated the imagination of Europeans. Sparked by Romanian physicist Hermann Oberth鈥檚 1923 book, The Rocket Into Interplanetary Space, the German Society for Space Travel was established in 1927. But when it was taken over by the Army in the 1930s, space travel took a back seat to military applications. The Third Reich demanded a rocket capable of delivering a heavy payload to distant targets. Under the leadership of Wernher von Braun, the Germans developed the terrifying V-2, which used a liquid oxygen-alcohol system and was capable of hitting targets with a 1000 pound TNT warhead at a range of 200 miles. The V-2 can be accurately described as the world鈥檚 first 鈥渟pace鈥� ship since it left the atmosphere at the top of its trajectory before plunging down to its target. No one could see it coming, hear it or stop it. Over 4000 V-2s were launched at targets in England and Western Europe, killing and maiming thousands. And that does not include the 20,000 slave labourers who perished in the factories where the rockets were produced.
After the war, von Braun, and about a hundred of his colleagues, ended up in American hands and went to work for the US Army in Hunstville, Alabama. Here von Braun, whose Nazi past was sanitized in order to make him into an American hero, designed the rockets that would eventually launch American astronauts into space. His efforts culminated in 1969 when the giant Saturn 5 roared into space, its first stage burning a fuel very much like Goddard鈥檚 original 1926 rocket. The second and third stages burned liquid hydrogen, the ideal fuel as had been suggested by Goddard forty years earlier. What a visionary this American physicist had been! In his high school oration in 1904, Goddard had voiced the opinion that 鈥渋t is difficult to say what is impossible, for the dream of yesterday is the hope of today and the reality of tomorrow.鈥澛� Indeed.
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