Category FLIGHT and M ОТІOIM

The Apollo 17 mission returned with a record amount of Moon rock—256 pounds (116 kilograms). This material, together with earlier soil samples and scientific data from the Moon landings, was eagerly studied by scientists all over the world. By the 1970s, however, the public had become less excited about manned spaceflights. Politicians also lost interest. NASA turned its attention to more practical space travel in the form of a reusable spacecraft, the Space Shuttle. Since 1972, there have been no further Moon landings.

Leftover Apollo equipment was used in 1973 in Skylab, an orbital space sta­tion used as a science laboratory. Three crews of U. S. astronauts visited Skylab, the third crew making the longest visit of eighty-four days.

The last Apollo spacecraft flew in 1975. Astronauts Tom Stafford, Donald Slayton, and Vance Brand docked in Earth orbit with a Soviet Soyuz space­craft carrying cosmonauts Alexei Leonov and Valery Kubasov. This mission, the Apollo-Soyuz Test Project, was intended to further U. S.-Soviet collaboration in space. With this project, the Apollo pro­gram came to a positive end.

The Apollo missions captured the imaginations of millions of people around the world who watched the Apollo 11 astronauts on television, from the thrilling moment of launch to their Moon walks and final splashdown.

The Apollo program was also an immense technical and industrial achievement. Thousands of workers in dozens of companies and research insti­tutes worked together to build the necessary rockets, spacecraft, and equip­ment. The program also boosted progress in microelectronics and com­puters. This important new technology would soon come to be used in further space exploration and on Earth.

Balloons were soon flying over the ocean. Frenchman Jean – Pierre Blanchard and American John Jeffries flew across the English Channel in 1785. In 1793 Blanchard completed the first balloon flight in the United States, traveling from Pittsburgh, Pennsylvania, to Gloucester County, New Jersey.

Early balloonists learned to control flight upward or down­ward. By letting out air or gas, the balloonist could descend. Throwing out ballast (sand or lead weights) enabled the balloon (now lighter) to rise. The dis­advantage of a balloon is that it cannot be steered-it drifts with the wind. Sails, oars, and even paddlewheels were tried for steering, all without success.

Balloon flights became popular entertainment, but they also had serious uses. The U. S. Army’s Balloon Corps used balloons for observation during the Civil War (1861-1865). Balloonists made the first scientific researches into the upper atmosphere. In the 1930s, Auguste

Piccard, a Swiss scientist, rode in a sealed cabin beneath a hydrogen bal­loon. He rose more than 50,000 feet (15,240 meters). In 1935 American bal­loonists Albert W. Stevens and Orvil A. Anderson ascended to 72,395 feet (22,066 meters). This record remained unbroken until the 1960s, when other balloonists in the United States reached

over 100,000 feet (30,480 meters). Unmanned balloons have flown as high as 170,000 feet (51,816 meters).

Some birds have as few as 900 feathers, while others have more than 25,000. This does not make much difference in their flying skills. The secret of flying is the bird skeleton. Bird bones are very light, but very strong-many bird bones are hollow. Because the bones are also fused (joined together), a bird has an amazingly strong frame, although it weighs little. Even the world’s heaviest flying bird-a bustard-weighs only 40 pounds (18.2 kilograms).

The largest muscles in a bird’s body work the wings (although in flightless birds, such as the ostrich, these big muscles work the legs). The wing muscles are in the chest, below the wing. The muscles are attached to the upper wing by tendons that work like pulleys. This streamlined body design gives the bird a high power-to-weight ratio, just like an aerobatic airplane. Its muscles provide the engine power to drive the wings. To fuel those muscles, most birds need a lot of food every day. Birds can inhale large amounts of air very quickly, using the oxygen to help provide energy for rapid flight.

A bird’s wings are equivalent to a person’s arms, with long “finger” bones carrying flight feathers, the longest feathers. The bird wing is curved like an airplane wing-slightly rounded on top, flatter underneath. This curved shape forces air to speed up when flowing over the top surface. The faster the airflow, the less air pressure there is above the wing. Because high-pressure air always moves to fill low-pressure space, the air beneath the wing moves upward. This movement creates lift beneath the wing, and the bird flies.

Wing shapes are a clue to how differ­ent birds fly. Fast-flying birds, such

as swifts and swallows, have long, narrow wings, often swept back like a jet fighter. Soaring birds, such as vultures and buzzards, have broad wings. Gliders-the alba­tross, for example-have long, straight wings.

Birds that need rapid takeoffs (like pheasants and prairie hens) and small birds that nest in shrubs or undergrowth usually have quite short, stubby wings.

In the late 1960s, Boeing produced new jet airliners for short – or medium-range flights—the 727 (1964) and the 737 (1968). These were smaller aircraft that were economical for airlines and able to operate from smaller airports.

After failing to win a government contract for a very large military trans­port, Boeing switched to building a giant passenger carrier. This new plane, the 747, had a distinctive “bubble” front, providing an upper deck for first-class passengers. It could seat about 400 passengers in its spacious main cabin, which was 185 feet (56 meters) long and 20 feet (6 meters) wide.

The 747 made long-haul flying much cheaper. Two 747 flights could replace up to ten flights by smaller airliners. Airport passenger handling facilities were strained at first, however, when

TECH*fcT ALK

BOEING AIRLINERS

Boeing’s family of commercial aircraft is designed for different routes. The vari­ous aircraft have ranges of between

2,0 miles (3,220 kilometers) and 9,000 miles (14,480 kilometers). A 777 can fly nonstop from New York to Jakarta in Indonesia. The seat capacities of recent Boeing models are:

• 737 up to 180 seats.

• 747 up to 416 seats.

• 767 up to 245 seats.

• 777 up to 368 seats.

• 787 up to 330 seats.

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two or three 747s landed at about the same time, unloading more than 1,000 passengers within minutes.

Boeing continues to build new airlin­ers. The 757, 767, and 777 were followed by the 787, the latest addition to the line. Each aircraft is designed to fit into a niche in the world air transportation market. Boeing also continues its research into new areas of aerospace through experimental aircraft, such as the X-43 hypersonic airplane.

SEE ALSO:

• Aerospace Manufacturing Industry

• Aircraft, Commercial • Aircraft, Experimental • Aircraft Design

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Dates of birth: Leila Marie: unknown; Samuel: March 6, 1867.

Places of birth: Leila Marie: unknown; Samuel: Davenport, Iowa.

Died: Leila Marie: February 5, 1939; Samuel: August 7, 1913.

Major contributions: Leila Marie: first woman to pilot a heavier-than-air craft; Samuel: inventor of the man-lifting kite and first person to fly an airplane in Britain.

amuel Franklin Cody was born Franklin Samuel Cowdery. He learned how to ride, shoot, and rope, and he joined a Wild West show soon after he turned twenty. About that time, he changed his name to Samuel Franklin Cody.

In 1890 Cody went to Europe to per­form. Soon after, he met Leila Marie Davis. By the late 1890s, Samuel and Leila Marie and her children—whom Cody adopted—were touring together. Leila Maire and her children took Cody’s name, and the couple worked together as partners in demonstrations of trick riding and sharp shooting.

At some point, Cody became inter­ested in flying kites. In about 1900 he developed a system he called his “man­lifting kite.” It included a pilot kite mounted at the top of a long cable; sev­eral lifter kites spaced along the cable; and a carrier kite, from which dangled a basket that could carry a person.

FALSE CLAIMS

By changing his name, Samuel Franklin Cody tried to advance his career by linking himself to William "Buffalo Bill" Cody, who led the most famous of all Wild West shows. He even claimed to be the famous Cody’s son until Buffalo Bill’s lawyers forced him to stop. Cody invented many stories about his early life to appear more colorful. Although widely accepted at the time, they are now known to be fictitious.

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Cody told the British army that his kites could be used to send officers into the sky to make observations of enemy troops. As a demonstration, Leila Marie Cody bravely went up in the kite in 1902, making her the first woman pilot of a heavier-than-air craft. Samuel Cody’s kite ascents finally convinced the army—it hired him as its chief kite instructor in 1905. Working at a military base, Cody continued his flights. In one ascent, an army officer was lifted more than 3,300 feet (1,006 meters) above the ground.

Cody also developed an interest in other kinds of flying. In 1905 he built a glider that traveled more than 740 feet (226 meters). Next he tried putting a motor on a kite, but that effort failed. Cody then worked with Colonel John Edward Clapper to build an airship. On

September 30, 1907, they had a successful 12-mile (19 kilo­meter) flight. Five days later,

Cody and Clapper flew the airship to and around London, thrilling thousands of onlookers.

Samuel Cody’s first air­plane flew on October 16,

1908. Although the flight lasted less than half a minute,

Cody became the first person to fly a plane in Britain and an instant national hero.

Cody continued experi­menting with aircraft, trying out new designs each time one of his flying machines crashed. He became a British citizen so that he could partici­pate in exhibitions and races open only to British citizens. On a 1910 flight, he set a record for the longest British flight in terms of both time (almost 5 hours) and distance—more than 185 miles (298 kilometers).

Cody’s next challenge was the reward offered by the Daily Mail news­paper to the first person to fly a circle around Britain, a distance of more than 1,000 miles (1,600 kilometers). In 1911, Cody beat eight other pilots to finish first.

In 1913 Cody began designing a sea­plane that he flew successfully. On a later flight, however, the plane ran into mechanical problems. It plunged to the ground, and Cody and a passenger were killed. Britain mourned the loss of their hero, and the army offered to bury him in a military cemetery. Tens of thou­sands of people lined the roads as Cody’s coffin passed to his final resting place. Leila Marie Cody died in 1939.

When America went to war in 1941, the DC-3 became even more valuable as the C-47 military transport. During World War II, the airplanes were built at three plants: in Long Beach and Santa Monica, California, and in Oklahoma City, Oklahoma.

In its military role as the C-47 and other models, the DC-3 underwent internal changes. For troop carrying, the passenger cabin was refitted with utility seats that were set along the sides facing inward. The C-47 had twin radial engines, giving it a cruising speed of 207 miles per hour (333 kilometers per hour), and it had a range of 2,125 miles (3,420 kilometers). It could carry
up to 6,000 pounds (2,725 kilograms) of freight or twenty-eight fully equipped paratroopers. It was known as the Skytrain, the Skytrooper, and the “Gooney Bird.”

The C-47 proved to be an outstand­ingly successful troop carrier and was also widely used to drop paratroopers and tow gliders. C-47s, known in Britain as Dakotas, flew secret missions, often at night, over Nazi-occupied Europe. They dropped Allied agents, guns, and sup­plies by parachute to Resistance fighters. The aircraft also became a familiar sight to troops fighting on the Pacific and Southeast Asian battlegrounds. C-47s flew over the Himalayas between India and China and dropped ammunition,

food, and fuel to soldiers in jungle clear­ings in Burma or on small Pacific islands.

C-47s took part in the D-Day inva­sion of German-occupied northern France in June 1944. They also dropped Allied airborne troops during the Arnhem and Nijmegen assaults (in the Netherlands) in September 1944. Douglas supplied more than 10,000 C-47s to the Allies during the war, and a further 2,000 were built in Russia for use on the Eastern Front.

There were even DC-3s flying on the other side in World War II. The Japanese had bought twenty DC-3s in 1939 and had acquired a license to manufacture the plane. During the war, more than 400 Japanese DC-3s were used by the Imperial Japanese Navy. These planes, known as Showa L2Ds, were used main­ly as personnel transports.

An engine is a machine that changes heat into motion. Powered aircraft are propelled through the air by at least one engine. Several different types of engines are used in aircraft. An engine used for flight needs to be relatively lightweight, small, powerful, and reliable.

The First Aircraft Engines

The first engines used in the earliest attempts to build powered aircraft were steam engines. They were powerful engines, but they were also very heavy. They did sometimes manage to lift an aircraft off the ground for a few seconds, but it soon became clear that a different sort of engine was needed.

When the Wright brothers looked for an engine to power the world’s first air­plane, they were unable to find anything suitable, so they decided to build their own engine. It was a small gasoline-

О Four basic types of turbine engines are used today: the turbojet, the turboprop, the turbofan, and the turboshaft.

more powerful engines. These large, powerful piston engines produced a lot of vibration. One way of smoothing out the shaking was to fit a heavy metal wheel, called a flywheel, to the engine. The spinning wheel evened out the pul­ses of power produced by the cylinders.

Amphibians, designed to land on both water and dry land, are more versatile than regular seaplanes and land-based planes. They are useful in remote regions such as northern Canada and Siberia in Russia, where there are plenty of bays, lakes, and rivers but few cities with airports. Amphibians were as pop­ular as land-based planes during the early years of aviation.

Amphibious airplanes continue to be useful for many tasks. One of the most enduring designs was the Canadian – built Noorduyn Norseman (1935), which is basically a very tough, high-wing
monoplane that could be fitted with wheels, floats, or skis (for snow and ice). Canada also produced the Canadair CL-215 (1966). This aircraft, still used today, was designed as a firefighting amphibian. It has two 600-gallon (2,271- liter) tanks for water scooped up while flying low over a lake or river and then dumped over wildfires. The Grumman Albatross (1947) also has enjoyed a long career as an amphibian, used by the U. S. Air Force and U. S. Coast Guard.

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SEE ALSO:

• Aircraft, Commercial • Aircraft, Military • Curtiss, Glenn • Hughes, Howard • World War II

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Future missions to planets will follow the examples of the Huygens/Cassini mission to Saturn’s moon Titan and Galileo’s voyage to Jupiter’s moon, Europa. Europa is especially interesting to scientists. One ambitious project, called Icepick, plans to send a diving probe to plunge into the waters of the ocean believed by many scientists to lie beneath the surface of Europa.

Such planetary missions take years to plan and years to fly. The European Space Agency’s Rosetta craft, which was launched in 2004, will not reach its tar­get (a comet) until 2014. Messenger,

only the second spacecraft ever sent to Mercury, was launched by the United States in 2005. It will not arrive near Mercury until 2011. NASA also plans to send the Juno probe to explore Jupiter, the biggest planet in the solar system, by 2010.

Scientists would welcome a future, safer method of recovering data from spacecraft after missions. The Genesis spacecraft, launched in 2001, spent 884 days orbiting the Sun, collecting minute particles of the stream of gases known as the “solar wind.” The plan was to return these samples to Earth, using helicopters to recover a capsule landed by para­chute. Unfortunately, the parachutes did not open correctly, and Genesis crashed into the Utah desert in September 2004.

Scientists are eager to extend our knowledge of other planets. They hope to study comets and asteroids and inves­
tigate the myriad stars that lie beyond our solar system. Space scientists are curious to examine the material of which comets are made. They want to explore the planets of the solar system, such as Saturn, which was visited by the Cassini probe in 2004. Above all, scien­tists want to probe the stars for evidence about how the universe was formed and to search around distant stars for Earth­like planets that might contain life.

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SEE ALSO:

• Fuel • NASA • Satellite • Space­flight • Space Probe • Space Shuttle

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ravity is a force of nature that everyone is familiar with. On Earth, gravity is the force that pulls everything downward. It also keeps the Moon in orbit around Earth and the planets in orbit around the Sun. All fly­ing machines must overcome its pull.

Gravity is a property of matter. It is a force that always pulls, never pushes. Every particle of matter has its own tiny force of gravity, which attracts every other particle of matter.

Sir Isaac Newton (1642-1727) made a scientific study of gravity. He discov­ered that the force of gravity between two objects depends on their masses and the distance between them. The greater the masses, Newton’s experiments showed, the stronger the force. Newton also found that the farther apart the masses are, the weaker the force. A big mass such as Earth has a strong force of gravity that gets weaker farther away.

Falling

Objects fall to the ground because of gravity. Common sense seems to suggest that heavy objects should fall faster than light objects, but that is not correct. Galileo Galilei (1564-1642) carried out experiments to show that heavy and light objects fall at exactly the same rate. Another way of saying this is that acceleration due to gravity does not depend on mass. If two lumps of clay, one twice as big as the other, are dropped from the same height, they fall

NEWTON’S UNIVERSAL LAW OF GRAVITATION

Isaac Newton’s Universal Law of Gravitation states that the force of gravity between two masses is directly proportional to the product of their masses and inversely propor­tional to the square of the distance between their centers. The equation that expresses this reads as follows:

F= Gm1m2/d. F is the force of grav­ity; G is the constant of gravitation; m1 is one mass; m2 is the other mass; d is the distance between the centers of the masses.

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at the same rate and hit the ground at the same instant.

Near Earth’s surface, falling objects accelerate due to gravity at about 32 feet per second per second (10 meters per second per second). This means that the object travels 32 feet per second (10 meters per second) faster every second. Objects falling through the air from a great height eventually stop speeding up because the force of gravity is balanced by air resistance pushing upward. The final speed of a falling object is called its terminal velocity.

In Earth’s gravity, if a feather and a hammer are dropped, the feather takes much longer to fall than the hammer.

The feather is so light and it has such a big surface area that its fall is slowed by air resistance much more than that of the hammer. In 1971,

U. S. astronaut David Scott took a feather and a hammer to the Moon and carried out an experiment. Without any air to slow the feather, it fell as fast as the hammer when Scott dropped them both. The two objects landed on the Moon’s sur­face at the same time.