Category FLIGHT and M ОТІOIM

Telecommunications providers use com­munications satellites (comsats), which function as relays for telephone, radio, and television signals. The first satellite able to relay a voice signal was launched in 1960; Telstar was the first real com­munications satellite, launched in 1962. Syncom 3, launched in geostationary orbit in 1963, relayed the 1964 Tokyo Olympics to U. S. viewers, the first televi­sion pictures sent across the Pacific Ocean. Intelsat 1, also known as “Early Bird,” relayed TV signals across the Atlantic in 1965. Satellites launched for commercial companies revolutionized satellite and cable TV. They made satel­lite television possible-today there are hundreds of channels, and live coverage of events is transmitted all over the world. Groups of satellites also provide worldwide phone networks.

Military comsats such as the U. S. Milstar system (launched in 1994) pro­vide secure communications that cannot be blocked. In the 1960s, the Russians launched a series of Molniya comsats into elliptical, 12-hour orbits, with perigees (low points) of no more than a few hundred miles and apogees (high

О Geostationary operational environmental satellites (GOES) provide views of Earth that help forecasters accurately predict emergency weather conditions. This GOES image shows Hurricane Andrew over the Gulf of Mexico in 1992.

points) of up to 25,000 miles (40,230 kilometers). This kind of orbit is now called a Molniya orbit. Less rocket power is needed to put a satellite into this orbit than into a high geostationary orbit.

The two world wars stimulated rapid progress in aeronautics as warring nations tried to produce the best fighter planes. Spotter planes that were used to spy on enemy forces in World War I (1914-1918) quickly developed into the
first fighters and bombers. Air speeds also increased. Before the war, most air­planes could reach a top speed of only about 35 to 45 miles per hour (about 56 to 72 kilometers per hour). By the end of the war, fighters such as the Sopwith Camel had a top speed of about 113 miles per hour (182 kilometers per hour).

During World War II (1939-1945), the top speed of propeller planes increased to more than 370 miles per hour (595 kilometers per hour). Jet fight­ers were developed during the war. The first, the German Messerschmitt Me-262, had a top speed of 540 miles per hour (869 kilometers per hour).

These and other developments were applied to airliners soon after the war. The first jet airliners were the De Havilland Comet and Boeing 707. Radar, developed during the war to detect

enemy aircraft by bouncing radio waves off them, became the basis of air traffic control systems that guide today’s air­craft safely along invisible lanes in the sky.

By 1969 the SR-N4 was carrying 600 passengers on ferry services between England and France at 80 miles per hour (129 kilometers per hour). The ACV fea­tured four gas turbine engines driving airscrews and a tough, flexible skirt to keep the air cushion in place. The skirt also allowed the 160-ton (145-metric – ton) craft to ride over low obstacles without air escaping.

The first ACV skirts were like rubber curtains, and they quickly wore out. The modern ACV has a bag skirt, which looks like a thick tube and is made of
tough nylon and plastic. The craft rests on the bag when it is not moving.

Another type of ACV was developed for use over water only. Known as the sidewall ACV, it has a skirt only at front and back and rigid panels on its sides. The sidewall ACV skims over the water, like a hydrofoil ship, but this type can­not operate overland.

The early pioneers of flight found out by trial and error what worked and what did not. In 1890 Clement Ader of France built a steam-powered airplane. It was a failure, but it showed other designers that steam engines were too heavy for use in airplanes.

Experiments sometimes cost lives. In 1899, British engineer Percy Pilcher was killed when his glider crashed shortly before he was due to test an airplane with an engine. Had he survived, Pilcher might have beaten the Wright brothers by making the first powered, controlled flight in an airplane.

In 1901, American experimenter Samuel Pierpoint Langley tested a

О This multiplane, photographed in 1911, was based on designs by Horatio Phillips and had 110 narrow wings. Although his designs appeared eccentric, Phillips’s experi­mental aircraft increased knowledge of aerodynamics and successful wing shapes.

model airplane. Encouraged by its performance, he built the full-size Aerodrome. The plane crashed into the Potomac River, not once but twice, on December 7 and 8, 1903. Nine days later the Wrights’ Flyer took to the air at Kitty Hawk, North Carolina.

Many pioneer airplanes look strange to modern eyes. Some planes of the 1910s and 1920s were “pushers” (their propellers faced backward); others were “tractors” (the propellers faced forward). Throughout this period, there were experiments with biplanes (with two wings), triplanes (with three wings), and multiplanes (with many wings).

In the 1930s, experimenters sought higher speed with monoplanes that had single wings, sleek metal bodies, and more powerful engines. The first rocket – powered airplane flew in Germany in 1928. By 1940 the German Project X produced the DFS 194, an experimental rocket plane that led to the Me-163 rocket plane of World War II. As the war began in Europe, the first experimental jet planes roared into the skies, starting in 1939 with the German Heinkel 178.

In the early days of flight, advances in aircraft design were often helped along or speeded up by prize competitions. Newspapers, aviation organizations, and wealthy people offered trophies and large cash prizes to aviators who could build aircraft that would win races and make historic flights.

Between 1913 and 1931, seaplanes competed for the Schneider Trophy. The

last three races were won by planes designed by Reginald Mitchell. When Britain needed a new fighter plane before World War II, Mitchell used his experience in designing racing planes to produce one of the most famous fighters of the war, the Spitfire.

Charles Lindbergh made the first solo nonstop flight across the Atlantic Ocean in 1927 to win the Orteig Prize. Lindbergh’s airplane was a standard Ryan M-2 airplane that was specially redesigned with bigger wings and extra fuel tanks for the long­distance flight.

The Gossamer Condor won the first Kremer Prize in 1977 for the first human-powered plane (using pedals) to fly a figure-eight course. In 1979 the Gossamer Albatross won the second Kremer Prize for the first human-powered flight across the English Channel in Europe. A third Kremer Prize, awarded for speed in a human-powered plane, was won in 1984 by a plane named the Monarch B.

Air races are still held today, but now they are more for sport and entertain­ment than to encourage advances in design. Some aircraft, however, are still specially designed to win prizes. The first privately developed space plane, SpaceShipOne, was designed by Burt Rutan to win the $10 million Ansari-X Prize in 2004. Rutan also designed the

Voyager airplane for the first nonstop round-the-world flight in 1986. He went on to design the Virgin Atlantic Global Flyer plane for the first solo, nonstop, round-the-world flight in 2005.

SEE ALSO:

• Aerodynamics • Bleriot, Louis

• Boeing • Control System • Curtiss,

Glenn • Engine • Materials and

Structures • Stability and Control

• Supersonic Flight

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Alcock and Brown were instantly hailed as heroes. The Daily Mail held a banquet in their honor, and King George V received them at Windsor Castle and awarded both pilots a knighthood. Vickers offered Alcock and Brown jobs for the rest of their lives.

Later in 1919, Alcock flew an exper­imental seaplane for Vickers across the English Channel to France. Thick fog caused his aircraft to crash, and the impact killed him.

Brown lived nearly thirty more years after Alcock’s death. He worked for

RE-CREATED FLIGHTS

In 2005 two fliers repeated Alcock and Brown’s legendary flight. Pilot Steve Fossett and copilot and navi­gator Mark Rebholz flew a Vimy that was a reconstruction of the original plane. Fossett and Rebholz took off from Newfoundland on July 3. They tried to follow faithfully the original flight path. Fossett flew the plane at low speeds of 75 miles per hour (121 kilometers per hour). Rebholz used only the type of navigational equipment that Brown had used on his flight. On July 4, 18 hours after takeoff, the airplane landed on a golf course in Ireland. The same replica aircraft was then used to repeat two other historic flights that had taken place in a Vimy: the first England-to-Australia flight of 1919 and the first England-to-South Africa flight of 1920.

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Vickers and then for an engineering company until World War II began. In 1939 Brown rejoined the military to train pilots in the British Royal Air Force. He died in 1948.

SEE ALSO:

• Biplane • Bomber • Navigation

• Pilot • World War I

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The first astronauts wore spacesuits throughout their missions. These suits were developed from the pressure suits worn by high-altitude fliers to combat the effects of altitude. The first astronaut to test a spacesuit outside a spacecraft was Soviet cosmonaut Alexei Leonov. In 1965, he stepped outside his Voskhod 2 orbiter and spent 24 minutes of extra­vehicular activity (EVA), linked to his spacecraft by two lines.

Today, Space Shuttle astronauts and Space Station crews are either tethered by a line to their spacecraft or have their boots locked into place on a robotic arm. They can also use a jetpack system called a simplified aid for EVA rescue (SAFER). First tested in 1994, the unit

can propel astronauts back to safety in emergencies—if they became untethered, for example.

Modern spacesuits have interchange­able parts in different sizes so suits can be adjusted to fit each astronaut. The Moon suits used by the Apollo astro­nauts were more comfortable than the first spacesuits because the Moon suits introduced rubberized joints that made walking and bending easier. The modern spacesuit, designed for floating rather than walking, is made of layers of syn­thetic materials—such as Kevlar, Teflon, and Dacron—with an outer skin of Teflon-coated glass fiber. The layers shield out harmful radiation and protect against the risk of puncture by dust par­ticles flying in space.

Temperatures in space are extreme: 250°F (121°C) in sun, and a freezing -250°F (-157°C) in shadow. An internal cooling system circulates water through tubes inside the spacesuit, while the suit’s heating elements prevent the astronaut from freezing when working in shadow. A gold-coated sun visor in the helmet shields the astronaut’s eyes from the sun’s glare, and flashlights on the helmet can be switched on to give extra light when working outside the spacecraft.

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NOTABLE ASTRONAUTS

John H. Glenn was the first American in orbit (1962) and, at age seventy-seven, the oldest person to go into space (1998).

Neil A. Armstrong and Edwin "Buzz" Aldrin were the first people to set foot on the Moon (1969).

John W. Young and Robert L.

Crippen made the first Space Shuttle flight (1981).

Guion S. Bluford was the first African American astronaut (1983).

Sally Ride was the first female U. S. astronaut (1983).

Svetlana Savitskaya was the first woman to make an EVA (1984).

Jake Garn, U. S. senator, was the first politician in space (1985).

Valeriy Poliyarkov stayed in space a record 437 days (1986-1987).

Mae Jemison was the first female African American astronaut (1992).

Bill Shepherd was the first U. S. astronaut to crew the International Space Station (2000).

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SEE ALSO:

• Apollo Program • Armstrong,

Neil • Challenger and Columbia

• Gagarin, Yuri • Glenn, John

• International Space Station

• Ride, Sally • Spaceflight

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When World War II ended in 1945, it had created a legacy of new aviation technology. Aircraft designers wondered how to use recently developed rocket engines and jet engines in civilian fly­ing. These developments had opened the door to supersonic flight, or flying faster than the speed of sound.

The speed of sound, in air at sea level, is about 761 miles per hour (1,225 kilometers per hour), but it is lower at higher altitudes. The speed of sound is also known as Mach 1. Twice the speed of sound is Mach 2, and three times the speed of sound is Mach 3.

TECH**TALK

Length: 31 feet (9.5 meters).

Wingspan: 28 feet (8.5 meters).

Weight: 12,250 pounds (5,562 kilograms).

Engine: Reaction Motors XLR-11- RM-3 four-chamber rocket engine.

Fuel: Alcohol and liquid oxygen.

Thrust: 6,000 pounds (2,722 kilo­grams or 26,689 newtons).

The Bell X-1 was shaped like a bullet for maximum streamlining. Its wings and tailplane were conventional in design. (In the 1940s, other experi­mental high-speed aircraft had strange shapes.) The stubby-winged X-1, however, had hidden secrets. Its wings were thin but very strong. A stabilizer, which the pilot could move up and down, improved stability and control. Later supersonic planes were also fitted with stabilizers.

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Although propeller aircraft had reached supersonic speed during dives, very little was known about how a plane behaved at such speeds. Nor did scien­tists know much about the effect of high-speed flying on pilots. Designers worried that pilots might lose conscious­ness or that the plane would become uncontrollable. Heat friction and pres­sure waves as the airplane reached supersonic speeds might shatter the air­craft into pieces.

U. S. scientists built the Experimental Sonic 1, or X-1 for short, to explore these problems. The X-1 was developed jointly by the U. S. Air Force, the National Advisory Committee for Aeronautics, and the Bell Company. Bell is now best known for making helicop­ters, but in 1942 it built the P-59 Airacomet, the first jet plane with a U. S.-built engine.

Like airplanes, some birds fly in forma­tion. Many people have admired the V-formation of a group of geese in flight. Formation flying offers an aero­dynamic benefit: each bird gets extra lift from the slipstream (the air pushed back) of the bird in front. The formation also keeps the birds together on long flights.

Some birds make incredibly long journeys during migration, crossing oceans and continents. Small migratory birds usually fly at night, stopping dur­ing the day to rest and feed. Larger birds often fly by day, resting at night.

How birds navigate is not clearly understood. They rely on instinct in some mysterious way. The European cuckoo lays its eggs in the nest of anoth­er breed of bird and flies away, leaving the chick to be raised by host parents.

The young cuckoo, without ever having had contact with its real parents, will then fly south to Africa in winter as those parents did. Birds follow visual landmarks such as rivers and mountains, and it is thought they also navigate by the stars and by Earth’s magnetic field. Many birds return to the same nesting site year after year.

ape Canaveral is a sandy headland on Florida’s Atlantic Ocean coast. (Cape Canaveral was officially renamed Cape Kennedy in 1963, but the name reverted to Cape Canaveral ten years later.) Cape Canaveral is home to two of the world’s most famous U. S. space launch sites, one of which is Cape Canaveral Air Force Station. The station, operated by the U. S. Air Force, is the East Coast spaceport for the Department of Defense. The other space­port located on Cape Canaveral is the Kennedy Space Center.

Cape Canaveral was chosen as the leading U. S. launch site for three reasons. First, it is close to the equator. During a launch, rockets get an extra push from Earth’s rotation, and this effect is great­est nearest the equator. Second, there is
a vast expanse of ocean to the east of Cape Canaveral. Rockets that fail are likely to fall into the ocean, not onto land. Third, the area has good trans­portation links with the rest of the United States. These connections are important for the delivery of rockets, spacecraft, and supplies.