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Brief
History of Rockets
Today's rockets are remarkable collections of human ingenuity
that have their roots in the science and technology of the
past. They are natural outgrowths of literally thousands
of years of experimentation and research on rockets and
rocket propulsion.
One
of the first devices to successfully employ the principles
essential to rocket flight was a wooden bird. The writings
of Aulus Gellius, a Roman, tell a story of a Greek named
Archytas who lived in the city of Tarentum, now a part of
southern Italy. Somewhere around the year 400 B.C., Archytas
mystified and amused the citizens of Tarentum by flying
a pigeon made of wood. Escaping steam propelled the bird
suspended on wires. The pigeon used the action-reaction
principle, which was not stated as a scientific law until
the 17th century.
About
three hundred years after the pigeon, another Greek, Hero
of Alexandria, invented a similar rocket-like device called
an aeolipile. It, too, used steam as a propulsive gas.
Hero
mounted a sphere on top of a water kettle. A fire below
the kettle turned the water into steam, and the gas traveled
through pipes to the sphere. Two L-shaped tubes on opposite
sides of the sphere allowed the gas to escape, and in doing
so gave a thrust to the sphere that caused it to rotate.
Just
when the first true rockets appeared is unclear. Stories
of early rocket like devices appear sporadically through
the historical records of various cultures. Perhaps the
first true rockets were accidents. In the first century
A.D., the Chinese reportedly had a simple form of gunpowder
made from saltpeter, sulfur, and charcoal dust. To create
explosions during religous festivals, they filled bamboo
tubes with a mixture and tossed them into fires. Perhaps
some of those tubes failed to explode and instead skittered
out of the fires, propelled by the gases and sparks produced
by the burning gunpowder.
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The
Chinese began experimenting with the gunpowder-filled tubes.
At some point, they attached bamboo tubes to arrows and
launched them with bows. Soon they discovered that these
gunpowder tubes could launch themselves just by the power
produced from the escaping gas. The true rocket was born.
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The
date reporting the first use of true rockets was in 1232.
At this time, the Chinese and the Mongols were at war with
each other. During the battle of Kai-Keng, the Chinese repelled
the Mongol invaders by a barrage of "arrows of flying fire."
These fire-arrows were a simple form of a solid-propellant
rocket. A tube, capped at one end, contained gunpowder.
The other end was left open and the tube was attached to
a long stick. When the powder was ignited, the rapid burning
of the powder produced fire, smoke, and gas that escaped
out the open end and produced a thrust. The stick acted
as a simple guidance system that kept the rocket headed
in one general direction as it flew through the air. It
is not clear how effective these arrows of flying fire were
as weapons of destruction, but their psychological effects
on the Mongols must have been formidable.
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Following
the battle of Kai-Keng, the Mongols produced rockets of
their own and may have been responsible for the spread of
rockets to Europe. All through the 13th to the 15th centuries
there were reports of many rocket experiments. In England,
a monk named Roger Bacon worked on improved forms of gunpowder
that greatly increased the range of rockets. In France,
Jean Froissart found that more accurate flights could be
achieved by launching rockets through tubes. Froissart's
idea was the forerunner of the modern bazooka. Joanes de
Fontana of Italy designed a surface-running rocket-powered
torpedo for setting enemy ships on fire.
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By
the 16th century rockets fell into a time of disuse as weapons
of war, though they were still used for fireworks displays,
and a German fireworks maker, Johann Schmidlap, invented
the "step rocket," a multi-staged vehicle for lifting fireworks
to higher altitudes. A large sky rocket (first stage) carried
a smaller sky rocket (second stage). When the large rocket
burned out, the smaller
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one
continued to a higher altitude before showering the sky
with glowing cinders. Schmidlap's idea is basic to all rockets
today that go into outer space.
Nearly
all uses of rockets up to this time were for warfare or
fireworks, but there is an interesting old Chinese legend
that reported the use of rockets as a means of transportation.
With the help of many assistants, a lesser-known Chinese
official named Wan-Hu assembled a rocket- powered flying
chair. Attached to the chair were two large kites, and fixed
to the kites were forty- seven fire-arrow rockets.
On
the day of the flight, Wan-Hu sat himself on the chair and
gave the command to light the rockets. Forty-seven rocket
assistants, each armed with torches, rushed forward to light
the fuses. In a moment, there was a tremendous roar accompanied
by billowing clouds of smoke. When the smoke cleared, Wan-Hu
and his flying chair were gone. No one knows for sure what
happened to Wan-Hu, but it is probable that if the event
really did take place, Wan-Hu and his chair were blown to
pieces. Fire-arrows were as apt to explode as to fly.
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Rocketry
Becomes a Science
During
the latter part of the 17th century, the scientific foundations
for modern rocketry were laid by the great English scientist
Sir Isaac Newton (1642-1727). Newton organized his understanding
of physical motion into three scientific laws. The laws
explain how rockets work and why they are able to work in
the vacuum of outer space. Newton's laws soon began to have
a practical impact on the design of rockets. About 1720,
a Dutch professor, Willem Gravesande, built model cars propelled
by jets of steam. Rocket experimenters in Germany and Russia
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began
working with rockets with a mass of more than 45 kilograms.
Some of these rockets were so powerful that their escaping
exhaust flames bored deep holes in the ground even before
lift-off.
During
the end of the 18th century and early into the 19th, rockets
experienced a brief revival as a weapon of war. The success
of Indian rocket barrages against the British in 1792 and
again in 1799 caught the interest of an artillery expert,
Colonel William Congreve. Congreve set out to design rockets
for use by the British military.
The Congreve rockets were highly successful in battle. Used
by British ships to pound Fort McHenry in the War of 1812,
they inspired Francis Scott Key to write "the rockets' red
glare," words in his poem that later became The Star- Spangled
Banner.
Even with Congreve's work, the accuracy of rockets still
had not improved much from the early days. The devastating
nature of war rockets was not their accuracy or power, but
their numbers. During a typical siege, thousands of them
might be fired at the enemy. All over the world, rocket
researchers experimented with ways to improve accuracy.
An Englishman, William Hale, developed a technique called
spin stabilization. In this method, the escaping exhaust
gases struck small vanes at the bottom of the rocket, causing
it to spin much as a bullet does in flight. Variations of
the principle are still used today.
Rockets continued to be used with success in battles all
over the European continent. However, in a war with Prussia,
the Austrian rocket brigades met their match against newly
designed artillery pieces. Breech-loading cannon with rifled
barrels and exploding warheads were far more effective weapons
of war than the best rockets. Once again, rockets were relegated
to peacetime uses.
Modern
Rocketry Begins
In
1898, a Russian schoolteacher, Konstantin Tsiolkovsky (1857-1935),
proposed the idea of space exploration by rocket. In a report
he published in 1903, Tsiolkovsky suggested the use of liquid
propellants for rockets in order to achieve greater range.
Tsiolkovsky stated that the speed and range of a rocket
were limited only by the exhaust velocity of escaping gases.
For his ideas, careful research, and great vision, Tsiolkovsky
has been called the father of modern astronautics.
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Early
in the 20th century, an American, Robert H. Goddard (1882-1945),
conducted practical experiments in rocketry. He had become
interested in a way of achieving higher altitudes than were
possible for lighter-than-air balloons. He published a pamphlet
in 1919 entitled A Method of Reaching Extreme Altitudes.
It was a mathematical analysis of what is today called the
meteorological sounding rocket.
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Goddard's
earliest experiments were with solid-propellant rockets.
In 1915, he began to try various types of solid fuels and
to measure the exhaust velocities of the burning gases.
While
working on solid-propellant rockets, Goddard became convinced
that a rocket could be propelled better by liquid fuel.
No one had ever built a successful liquid-propellant rocket
before. It was a much more difficult task than building
solid- propellant rockets. Fuel and oxygen tanks, turbines,
and combustion chambers would be needed. In spite of the
difficulties, Goddard achieved the first successful flight
with a liquid- propellant rocket on March 16, 1926. Fueled
by liquid oxygen and gasoline, the rocket flew for only
two and a half seconds, climbed 12.5 meters, and landed
56 meters away in a cabbage patch. By today's standards,
the flight was unimpressive, but like the first powered
airplane flight by the Wright brothers in 1903, Goddard's
gasoline rocket was the forerunner of a whole new era in
rocket flight.
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Goddard's
experiments in liquid-propellant rockets continued for many
years. His rockets became bigger and flew higher. He developed
a gyroscope system for flight control and a payload compartment
for scientific instruments. Parachute recovery systems were
employed to return rockets and instruments safely. Goddard,
for his achievements, has been called the father of modern
rocketry.
A third great space pioneer, Hermann Oberth (1894-1989)
born on June 25, 1894 in Hermannstadt (Transylvania), and
died on December 28, 1989 in Nuremberg, Germany, published
a book in 1923 about rocket travel into outer space. His
writings were important. Because of them, many small rocket
societies sprang up around the world. In Germany, the formation
of one such society, the Verein fur Raumschiffahrt (Society
for Space Travel), led to the development of the V-2 rocket,
which was used against London during World War II. In 1937,
German engineers and scientists, including Oberth, assembled
in Peenemunde on the shores of the Baltic Sea. There the
most advanced rocket of its time would be built and flown
under the directorship of Wernher von Braun.
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The
V-2 rocket (in Germany called the A-4) was small by comparison
to today's rockets. It achieved its great thrust by burning
a mixture of liquid oxygen and alcohol at a rate of about
one ton every seven seconds. Once launched, the V-2 was
a formidable weapon that could devastate whole city blocks.
Fortunately
for London and the Allied forces, the V-2 came too late
in the war to change its outcome. Nevertheless, by war's
end, German rocket scientists and engineers had already
laid plans for advanced missiles capable of spanning the
Atlantic Ocean and landing in the United States. These missiles
would have had winged upper stages but very small payload
capacities.
With
the fall of Germany, many unused V-2 rockets and components
were captured by the Allies. Many German rocket scientists
came to the United States. Others went to the Soviet Union.
The German scientists, including Wernher von Braun, were
amazed at the progress Goddard had made.
Both
the United States and the Soviet Union realized the potential
of rocketry as a military weapon and began a variety of
experimental programs. At first, the United States began
a program with high-altitude atmospheric sounding rockets,
one of Goddard's early ideas. Later, a variety of medium-
and long-range intercontinental ballistic missiles were
developed. These became the starting point of the U.S. space
program. Missiles such as the Redstone, Atlas, and Titan
would eventually launch astronauts into space.
On
October 4, 1957, the world was stunned by the
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news
of an Earth-orbiting artificial satellite launched by the
Soviet Union. Called
Sputnik I, the satellite was the first successful entry
in a race for space between the two superpower nations.
Less than a month later, the Soviets followed with the launch
of a satellite carrying a dog named Laika on board. Laika
survived in space for seven days before being put to sleep
before the oxygen supply ran out.
A
few months after the first Sputnik, the United States followed
the Soviet Union with a satellite of its own. Explorer I
was launched by the U.S. Army on January 31, 1958. In October
of that year, the United States formally organized its space
program by creating the National Aeronautics and Space Administration
(NASA). NASA became a civilian agency with the goal of peaceful
exploration of space for the benefit of all humankind.
Soon, many people and machines were being launched into
space. Astronauts orbited Earth and landed on the Moon.
Robot spacecraft traveled to the planets. Space was suddenly
opened up to exploration and commercial exploitation. Satellites
enabled scientists to investigate our world, forecast the
weather, and to communicate instantaneously around the globe.
As the demand for more and larger payloads increased, a
wide array of powerful and versatile rockets had to be built.
Since the earliest days of discovery and experimentation,
rockets have evolved from simple gunpowder devices into
giant vehicles capable of traveling into outer space. Rockets
have opened the universe to direct exploration by humankind.
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