Category FLIGHT and M ОТІOIM

Trips to the ISS or to the Moon— and the far longer journey to Mars—still rely on conventional rocket launch and propulsion systems. Alternative systems will be needed for longer flights to explore deep space beyond the solar sys­tem. Scientists are investigating ion engines to replace chemical-fuel rockets
for long missions. An ion engine ejects positive ions (electrically charged parti­cles) to propel the spacecraft. It gives just a small thrust, but it is very effi­cient, needs little fuel, and can be made very light. Over many months, an ion – engine spacecraft could accelerate to very high speeds.

Another possibility is the solar-sailed spacecraft. A solar sail is a panel made from reflective materials; instead of catching the wind like a sailing ship, the solar sail is “blown along” by streams of light particles (photons) emitted from the Sun. A solar spacecraft would not need to carry onboard fuel. Although acceleration is slow to start with, it could eventually reach speeds of

200,0 miles per hour (322,000 kilome­ters per hour). Such a craft could travel
to the edge of the solar system in eight years, compared with the forty years taken by the Voyager 1 spacecraft.

GPS satellites last up to ten years, and new satellites are launched from time to time to replace older satellites. Each new generation of satellites is more advanced than the previous generation.

The first generation of GPS satellites was called Block I. These were experi­mental satellites used to test the system. Block II satellites formed the first opera­tional network. Block IIA satellites are a more advanced version of these. The next generation—Block IIR satellites— can be reprogrammed in space to fix

problems and upgrade their services.

The updating continues. Block IIR satellites are already being replaced with a new generation of satellites called Block IIR-M. Block IIF satellites are due for launch in 2009, and yet another new generation, Block III, is due for launch in 2012. Block III satellites will transmit more signals more powerfully on more frequencies. This will make it much easier to pick up GPS signals with less powerful receivers, and GPS equipment will shrink in size in the coming years. In the future, many portable products— from watches and personal music play­ers to cell phones and laptop comput – ers—may have built-in GPS receivers.

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Gossamer Penguin

Type: Experimental aircraft.

Manufacturer: AeroVironment, Inc.

First flight: April 7, 1980.

First solar-powered flight: May 18, 1980. Primary use: Research.

ossamer Penguin was the world’s first solar-powered airplane to carry a human pilot. It made its first flight in 1980. Gossamer Penguin is one of several experimental aircraft designed to investigate the possibility of using energy from the Sun, rather than fossil fuels, to power airplanes of the future. The advantage of a solar airplane is that it could fly for many days with­out ever having to land, because its power source (sunlight) is all around it in the atmosphere.

The inventor of Gossamer Penguin was Dr. Paul MacCready, a pioneer of alternative airplane technologies. In 1977, he built Gossamer Condor, a pedal-powered plane that won the Kremer Prize. This award had been offered since 1959 to any inventor who could build a human-powered airplane capable of flying a figure-8 course around two markers placed 0.5 miles (0.8 kilometers) apart, while staying at least 10 feet (3 meters) off the ground.

MacCready followed up his 1977 achievement in 1979 with Gossamer Albatross. This was the first human – powered airplane to fly across the English Channel between England and France. The pilot’s pedaling provided the energy to turn a propeller and proved that lightweight pedal-planes could fly considerable distances using very little energy. Duration of flight, however, depended on a human pilot who soon got tired.

The Sun, on the other hand, offers limitless energy, so inventors are very interested in solar-powered airplanes. The first solar-powered airplane was Sunrise II, a remote-controlled vehicle built by Robert Boucher in 1974.

Using the experience they had gained with Gossamer Albatross, MacCready and his team, advised by Boucher, built a version three-fourths the size, which was powered by an Asro-40 electric motor. The electric plane, Gossamer Penguin, took to the air in 1980. Like Gossamer Albatross, it was made of lightweight plastic, carbon fiber, poly­styrene, and sheet film. Power for the motor came either from twenty-eight batteries or from 3,920 solar cells, which could convert sunlight into electricity. The cells were mounted on the plane’s 71-foot-wide (22-meter-wide) wings.

The first flight, using battery power, took place on April 7, 1980, at Shafter Airport near Bakersfield, California. It was made by MacCready’s son (also named Paul), then age thirteen and weighing only 80 pounds (36 kilo­grams). The boy then made one short solar-powered flight on May 18.

More solar-powered flights were soon made in the Gossamer Penguin by pilot Janice Brown, who weighed in at around 100 pounds (45 kilograms).

О The solar – powered Gossamer Penguin is flown here by schoolteacher Janice Brown, a qualified pilot. The solar panel (top) is tilted toward the Sun.

On August 7, 1980, she flew the Penguin for about 2 miles (3 kilometers) in a flight lasting 14 minutes.

After the Gossamer Penguin, the MacCready team built Solar Challenger. This plane had smaller wings but an extra-large rear stabilizer. The stabilizer offered enough surface area for 16,128 solar cells, which meant the Solar Challenger was a lot more powerful than the Penguin. In 1981, the Solar Challenger became the first solar-pow­ered airplane to cross the English Channel, completing a trip of 161 miles (259 kilometers) from north of Paris, France, to Kent, England.

The success of Gossamer Penguin and Solar Challenger was followed up by
later solar airplanes, such as Pathfinder. This unmanned research airplane, devel­oped by NASA, first flew in 1993. Pathfinder and its successor, Pathfinder Plus, set several altitude records, reach­ing a height of over 80,000 feet (24,400 meters) in 1998.

Solar-powered flying wing airplanes, remotely controlled from the ground, may someday be able to fly for weeks or months and help carry out scientific research, mapping, and other tasks.

SEE ALSO:

• Aircraft, Experimental • Energy

• Fuel • Future of Aviation

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A twin-rotor helicopter has a long, wag­onlike body-for carrying passengers or

О A twin-rotor CH-47D Chinook carries a fork­lift as part of a recovery mission in Iraq in 2006.

cargo-and a large rotor at either end. One of the first “tandem rotor” heli­copters was the Piasecki PV-3 (1945), which was nicknamed the “flying banana.” The Piasecki PV-3 was able to carry ten people at 120 miles per hour (193 kilometers per hour).

The most famous example of a twin – rotor wagon helicopter is the CH-47 Chinook. In these large helicopters, the tail rotor rotates at a slightly higher level than the front rotor. The two rotors turn in opposite directions to prevent the helicopter from spinning around in the air. These big machines are less agile

THE CHINOOK

The Piasecki company pioneered the twin-rotor wagon helicopter with the "flying banana" of 1945. Piasecki later became Vertol (1956) and sub­sequently merged into Boeing. Its most famous helicopter is the CH-47 Chinook. First flown in 1961, the Chinook has a top speed of about 180 miles per hour (290 kilometers per hour) and a payload capacity of 14 tons (13 metric tons). The Chinook has seen action in combat zones around the world and is one of the most versatile and hard-working air­craft in history.

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than single-rotor helicopters, and pilots have to watch out that the long rotor blades do not smash into buildings or trees when flying low or landing. A vari­ation of the twin-rotor design is the coaxial-rotor helicopter, in which the two rotors are mounted one above the other.

new era in space exploration began on November 20, 1998, when the first module of the International Space Station (ISS) was launched into space. The space station is an orbital science laboratory and research facility, circling Earth at a height of 200-250 miles (320-400 kilo­meters). The ISS makes almost sixteen orbits every day-each orbit lasts 91.61 minutes. The space station’s average speed is 17,165 miles per hour (27,620 kilometers per hour). Since 2000, the ISS has been staffed by teams of astronauts.

The Space Station Concept

The term “space station” was first used in 1923 by German writer Hermann

Oberth, who foresaw a giant wheel in space from which astronauts might travel to the Moon and to the other planets. Rocket engineer Wernher von Braun described a similar concept in 1952. Orbital space stations have fea­tured in science fiction books and movies, such as 2001: A Space Odyssey. In many stories, a space station was a spaceport for rockets. These fictional space stations spun like mini-planets, with centrifugal force producing artifi­cial gravity so that the people inside did not float around.

The world’s first real space station, a much smaller structure, was launched in 1971. This was Salyut 1, launched by the Soviet Union. It was followed in 1973 by the first U. S. space station, Skylab,

which was visited by three crews of astronauts. The Soviets flew much longer missions than the Americans,

with some cosmonauts living in orbit for a year or more. In 1986 the Soviet Union

launched Mir, a space station big enough for six people.

In 1995 the U. S.

Space Shuttle Atlantis

docked with Mir, the

О In December 1998, the U. S. module Unity (left) was attached to the Russian module Zarya (right) in the first phase of construction of the ISS.

first time a U. S. spacecraft had linked up with the Russian space station. The modular design of Mir, with its solar panel “wings” and the docking unit used to link with the Shuttle, were forerunners of systems later developed for the International Space Station.

Today, the Kennedy Space Center is home to NASA’s Launch Services Program. The objectives of this pro­gram include sending robot space probes out across the solar system. These missions have included the Mars Exploration Rovers, the Huygens/ Cassini mission to Saturn, sending Deep Impact to Comet Tempel 1, and the launch of Solar and Heliospheric Observatory (SOHO), which studied the Sun. In addition, astronauts train at the space center in preparation for future missions.

Space Shuttle flights have been at the heart of the Kennedy Space Center’s activities since the first Shuttle, Columbia, was delivered to the spaceport in March 1979. The Kennedy Space Center is where each Space Shuttle mission begins. Technicians at the VAB
prepare each shuttle spacecraft for its next flight, bringing together compo­nents of the spacecraft and scientific apparatus from across the nation and from abroad. Space Shuttles are differ­ent in shape from rockets, so the north door of the huge assembly building had to be widened by 40 feet (12 meters) to allow the spacecraft, with its 78-foot (24-meter) wingspan, to pass through it. A huge crawler tractor transports the Space Shuttle to a launch pad. Two launch pads at LC-39, 39A and 39B, are used for Space Shuttle launches.

The Kennedy Space Center is the pre­ferred landing site for the Space Shuttle when it returns from space. It has one of the world’s largest airstrips, with a runway 15,000 feet (4,600 meters) long. Facilities at Kennedy include the Orbiter Processing Facility, where Space Shuttles are serviced after landing and their payloads removed.

The space center also has facilities that recycle the Space Shuttle’s solid – fuel rocket boosters and parachutes. The descent parachutes, which return spent boosters into the Atlantic Ocean after a Space Shuttle takeoff, are collected, washed, dried, and prepared for their next mission.

LC-39 is the only active launch cen­ter at the Space Center, but other launches take place from the neighbor­ing Cape Canaveral Air Force Station. The John F. Kennedy Space Center is like a small city, with more than 10,000 employees. Cape Canaveral has become a popular visitor attraction, and every year many families tour the Space Center and the Astronaut Hall of Fame. As well as seeing spacecraft and launch facilities, visitors can enjoy IMAX space movies and interactive flight simulators that bring alive the space age.

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Bad weather forced Lindbergh to wait to fly to New York. While he was preparing for his flight, two groups had tried and failed to win the Orteig Prize. Even as Lindbergh waited for the weather to clear so he could leave San Diego, a two-man French team took off from Paris and headed toward New York. After making great progress, they disap­peared at sea on May 9, 1927.

On May 10, Lindbergh left California. He flew to St. Louis, reaching it in record

TEC

SPIRIT OF ST. LOUIS

Model: Ryan NYP.

Structure: single-engine monoplane. Wingspan: 46 feet (14 meters). Length: 27.6 feet (8.4 meters). Engine: Wright Whirlwind, 237 horsepower.

Fuel capacity: 450 gallons (1,703 liters).

Speed: 120 miles per hour (193 kilometers per hour).

Range: 4,100 miles (6,597 kilometers).

4.

time, and after a brief rest, he flew onward again to New York.

When Lindbergh landed in New York on May 12, he met other teams eager to win the prize. All the teams were grounded, however, by poor weather over the Atlantic Ocean.

On the night of May 19, Lindbergh heard the weather was to change the next day. Unable to sleep, he drove to

the airfield hours before dawn on May 20, 1927.

Later that morning, the plane was brought onto the runway. At 7:54 a. m., Lindbergh told his crew, “So long!” and took off, heading east. Lindbergh main­tained a steady speed to conserve fuel. As the day passed, he crossed New England and northeastern Canada. Exhausted by lack of sleep, he had to fight to stay awake.

That night, Lindbergh was over the Atlantic and steering by the stars. When he entered clouds, he feared losing course and also that ice would coat the wings and weigh down the plane. Lindbergh flew around the cloud banks, often changing course. He continued to fight sleep all night.

A few hours after dawn, he spotted some fishing boats. Lindbergh asked for the direction of Ireland by shouting, but heard no response. Some hours later, he

О Charles Lindbergh is introduced by President Calvin Coolidge to a huge crowd gathered in Washington, D. C., in June 1927 to celebrate his successful flight.

spotted the Irish coast. He had traveled about 3,000 miles (4,830 kilometers) and was only a few miles off course. As people below cheered, Lindbergh headed to the coast of mainland Europe.

It was nightfall again-about 10 p. m. local time-when the exhausted pilot reached Paris, the capital of France, on May 21, 1927. When he spotted Le Bourget, the city’s airfield, Lindbergh nosed the plane down. He landed 33/2 hours after taking off and was greeted by a joyous crowd.

The only weapons that can stop ballistic missiles today are other missiles. The Patriot missile system uses radar to detect incoming missiles when they are 50 miles (80 kilometers) away. The missile is fired from a launch tube. Within a second, it is flying faster than the speed of sound. Radar waves fired at

the target bounce back and are received by the missile, which flies toward it. The Patriot missile must explode at precisely the right split second to destroy the enemy missile.

Patriot is a short-range antiballistic missile that can deal with small ballistic missiles and cruise missiles. The long­distance ICBMs are so fast and powerful that they have to be stopped much earli­er in their flight, when they are far away from their targets. The Strategic Defense Initiative (SDI) project of the 1980s, nicknamed “Star Wars,” was going to use laser battle stations in orbit to shoot down missiles as they climbed into space. Such powerful lasers have
destroyed missiles in tests, but it is very difficult to get them to work well in the real world. The SDI program was eventu­ally abandoned. Antiballistic missiles are still being developed and tested to deal with ICBMs. As new threats appear in a changing world, future antiballistic mis­siles may be carried by ships at sea so that they can be moved within range of targets in different places.

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SEE ALSO:

• Aircraft, Military • Ballistics

• Bomber • Fighter Plane • Global

Positioning System • Radar • Rocket

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After the Apollo mission, NASA experi­enced a falling off in public interest in space. The agency also was hampered by financial restraints, and it had to cut back on some programs. In 1975, NASA cooperated with the Soviet space agency to run the Apollo Soyuz Test Project, a joint flight by U. S. and Soviet astro­nauts. The project foreshadowed today’s cooperation with Russia and other
nations on the International Space Station (ISS). NASA had originally planned to launch its own space station, as authorized by Congress in 1984. Eventually, with costs high and rising, it was decided that an international partnership was more appropriate. The ISS was the suc­cessful result of this cooperation, and it has been consistently crewed by a changing group of astronauts since 2000.

In 1981, NASA astronauts flew the first reusable Space Shuttle; in 1983, NASA astronaut Sally K. Ride became America’s first woman in space when she flew on the STS-7 Space Shuttle mission. The Space Shuttle, used to supply the ISS and for satellite launches and other duties, has absorbed much of NASA funding and posed some major chal­lenges since it first flew. It has proved a valuable spacecraft, however.

Two major Space Shuttle accidents caused some critics to question NASA’s safety standards and operational sys­tems. In 1986, Challenger exploded shortly after takeoff, killing all seven crew members. In 2003, Columbia broke up shortly before it was due to land. Again, all seven crew members died. Space Shuttles were grounded after each of these disasters, while NASA and its partners involved in the program inves­tigated the causes. In both cases, a fault was identified and rectified by design changes. The three remaining Space Shuttles were back in operation by 2005.

О The International Space Station, a cooperative project involving several nations, began with the launches of Russian module Zarya and U. S. module Unity. This photograph shows Unity in the foreground, being delivered by NASA’s Space Shuttle Endeavour for rendezvous with Zarya.

pilot is the person who controls an aircraft. The name “pilot” was originally given to someone who steers a ship. Pilots fly everything from large airliners and fast military jets to airships and balloons. They also fly light aircraft, business jets, cargo planes, crop dusters, search-and-rescue helicopters, air ambulances, and other aircraft types. Requirements for a good pilot are sharp eyesight, intelligence, and calm judg­ment. All pilots must be physically fit and mentally alert.

Pioneers and Celebrities

The first pilots taught themselves to fly and were often their own mechanics as well. The world’s first aero club was set up in France in 1898—five years before the Wright brothers’ famous 1903 flight. The Aero Club of America was founded in November 1905. Among early avia­tors were Glenn Curtiss—who flew his June Bug airplane for the first time in 1908—and Louis Bleriot, the first air­plane pilot to fly from France to England, in 1909. The world’s first inter­national aviation meet, at Reims, France, in the summer of 1909, saw just twenty – three airplanes flying.

During World War I (1914-1918) airplane pilots earned a reputation for gallantry and chivalry. Fighter “aces,” such as American Captain Edward V. Rickenbacker, dueled in the skies. The first African American combat pilot, Eugene Bullard, was denied entry into the U. S. Army Air Corps on racial grounds and flew instead with the French Flying Corps. After the war, barnstormers (stunt pilots) thrilled crowds across the country with aero­batic shows. Women also took to the air. Ruth Law, an American pilot, was the first woman to loop the loop, in 1916. Bessie Coleman was the first female African American pilot.

О Eugene Jacques Bullard, the first African American combat pilot, flew for France during World War I. He later fought with the French Resistance in World War II and returned to the United States after being wounded.

EARLY WOMEN PILOTS

The world’s first ever female pilot was Elise Raymonde Delaroche of France, who received Pilot’s Certificate Number 36 in March 1910. She was killed in an airplane accident in 1919. Harriet Quimby, the first female American pilot, gained her pilot’s license in August 1911. On April 16, 1912, Quimby became the first woman to fly an airplane across the English Channel between England and France.

Men and women pilots flew stunts for movies—racing trains and flying under river bridges—and competed in air races. Record-breaking flights turned pilots into celebrities. Charles Lindbergh (the first pilot to fly solo across the Atlantic Ocean, in 1927) and Amelia Earhart (the first woman to achieve this feat, in 1932) were as famous as movie stars. Ruth Nichols was the first woman pilot to land in every one of the states of the United States. Clyde Pangborn and Hugh Herndon flew nonstop across the Pacific Ocean in 1931, and Wiley Post circled the world solo in 1933.

О In 1929, James H. Doolittle (1896-1993) made the world’s first instruments-only takeoff, level flight, and landing. In 1932, he set a world speed record for land planes. During World War II, he led the first bombing raid on Tokyo, Japan, and later commanded the Eighth Air Force in Europe and on the island of Okinawa, Japan.

THE TUSKEGEE AIRMEN

Until 1940, African Americans were not allowed to fly in the U. S. military. In 1941, how­ever, the U. S. Army Air Corps formed an all-black unit in Tuskegee, Alabama. Ground crew, navigators, pilots, and weapons crews were rigorously trained for combat at the Tuskegee Army Air Field (TAAF) and elsewhere in the United States. By 1946, almost 1,000 pilots had completed training. About 450 of these men served overseas during World War II. The Tuskegee airmen, as they became known, achieved an outstanding record, gaining respect in an era when prejudice, segregation, and lack of opportunity were the norm for African Americans. They flew thousands of missions, destroyed over 1,000 enemy aircraft, and received hundreds of medals, including more then 150 Distinguished Flying Crosses.

Modern propeller planes have their pro­pellers at the front, pulling the plane through the air. These are called tractor
propellers. In the early days of aviation, it was just as common for planes to have their propellers at the back, pushing the aircraft. The first successful powered air­plane, the Wright brothers’ Flyer, had two pusher propellers behind the wings.

Pusher propellers were popular because they did not get in the way of the air flowing over the wings. Without an engine or propeller in the way, the pilot had a great view ahead. It also was eas­ier to fit guns in the nose of a fighter

PROPROTORS

The strangest propellers are called proprotors. They have this name because they work like helicopter rotors part of the time and like propellers the rest of the time. Compared to regular propellers, proprotors are enormous. The propellers of a C-130 Hercules cargo plane, for example, are 13.5 feet (4 meters) across. The V-22 Osprey’s proprotors are nearly three times as big: 38 feet (12 meters) across. When the Osprey is on the ground, its engines are tipped up, pointing straight up in the air. Its two propellers look like helicopter rotors, and they work in the same way-when they spin, they lift the Osprey straight up into the air. Then the engines swivel forward, and the rotors work like propellers.

C The Osprey’s engines and pro­pellers tilt up (top left) for vertical takeoff. The engines tilt down and the propellers face forward (bottom left) for level flight.

plane that had its engine and propeller mounted in back.

Pusher propellers had drawbacks, however. They made it harder for pilots to escape from planes in the air without hitting a propeller. Also, the heavy weight of an engine at the back of a plane could be dangerous in a crash. It could move forward and crush the cock­pit. The problem of fitting guns to fight­er planes with propellers at the front was solved during World War I (1914-1918) by a device called an interrupter gear. It stopped a machine gun from firing when a propeller blade was in front of the gun barrel. The gun was synchronized to fire through the spaces between the blades. By the end of the war, nearly all fighter planes had their propellers at the front.