Category FLIGHT and M ОТІOIM

Even before President Kennedy made his challenge, NASA had launched Project Mercury. The project took the first American, Alan Shepard, into space on May 5, 1961, but he did not orbit Earth. After a second suborbital flight in 1961 by U. S. astronaut Virgil “Gus” Grissom, the first orbital flight by a U. S. astronaut was made by John Glenn on February 20, 1962. Three more Mercury flights followed, testing various aspects of spaceflight and increased flight time.

NASA’s next program was Project Gemini, designed to address some of the challenges faced in taking people to the Moon. NASA had chosen an option that would involve a rendezvous, or steering two spacecraft near each other. It would also require docking, which meant join­ing the two spacecraft together. None of this had been done before, and the steer­ing and navigation techniques needed to perform the tasks had never been tested.

In 1965 and 1966, ten manned Gemini missions tested several new space techniques. Gemini 3 had the first on-board computer used by astronauts. Ed White became the first American to “walk” in space when he left the safety of Gemini 4 and floated in space attached by two cords. Gemini 6 and Gemini 7 achieved the first rendezvous when they met up in December 1965. The astronauts on Gemini 7 stayed in space for two weeks, showing that it was possible for people to survive long enough to travel to the Moon and back. On March 16, 1966, Gemini 8 performed the first docking of two space vehicles in orbit. The docking was performed by Neil Armstrong, who would be the com­mander of Apollo 11. All the Gemini flights contributed vital knowledge and experience to Project Apollo.

Other industries are beginning to use avionics technology that was developed for aircraft and spacecraft. Some ships are now fitted with transponders that send out a radio signal to identify the ship, just like airliner transponders. The control center of a modern passen­ger liner or cargo ship is known as the bridge. The bridge is fitted with flat panel screens showing information col­lected by sensors all over the ship.

Many vehicles now have electronic systems to control their engines, just like a plane’s engine management system. Increasing numbers of vehicles are using the same satellite navigation system that commercial and military aircraft use.

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SEE ALSO:

• Cockpit • Communication • Control

System • Fighter Plane • Materials

and Structures • Navigation • Radar

• Space Shuttle

Venturis are used in the fuel system of some small piston engines in aircraft. Air flows into the engine through a venturi tube. The air speeds up as it squeezes through the narrowest part of the tube. According to Bernoulli’s

О This diagram shows Bernoulli’s Principle as it applies in a venturi tube (top) and to an airfoil in flight (bottom).

DANIEL BERNOULLI (1700-1782)

Daniel Bernoulli was born in Groningen, a city in the Netherlands in Europe. The Bernoulli family produced a number of outstanding mathematicians, but Daniel is the most famous. After gaining a doctorate in medicine, he became a professor of mathematics at St. Petersburg in Russia in 1725. In 1733, Bernoulli moved to Basel, Switzerland, where his family came from originally. He worked first as a professor of anatomy and botany and then of natural philosophy at the University of Basel. Bernoulli’s great work, a book called Hydrodynamica, was published in 1738.

О Daniel Bernoulli’s Hydrodynamica included a description of Bernoulli’s Principle.

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Principle, the air pressure where the tube narrows falls. The fuel pipe is connected to the venturi at this point. The low air pressure inside the venturi sucks a spray of fuel droplets into the engine along with the air. The part of the engine that does this is called the carburetor.

Bernoulli’s Principle is often used to explain how an aircraft wing produces lift. The air that flows over the curved top of the wing speeds up, and the air pressure there falls. Below the wing, the air pressure increases. Low pressure above the wing and high pressure below it are often said to create the upward force of lift.

In fact, lift is more complex than this. The difference in air pressure does not explain all the lift produced by the wing. The curved shape of a wing and its angle, or tilt, deflects air downward. According to Newton’s third law of motion, to every action there is an equal and opposite reaction. So, deflecting air downward also produces the upward force of lift.

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SEE ALSO:

• Laws of Motion • Lift and Drag

• Newton, Isaac • Pressure • Wing

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The company builds a wide range of commercial airplanes, from the long – serving 747 airliner to the new 787 Dreamliner. Military aircraft include the C-17 Globemaster, the CH-47 Chinook twin-rotor transport helicopter, the AH – 64D Apache attack helicopter, and the V-22 Osprey tilt-rotor V/STOL airplane.

The company has a huge program of fighter planes, including F/A-18 Hornet, F-15 Eagle, and F-22 Raptor fighters. In partnership with the Northrop Grumman Corporation, Boeing built the B-2 stealth

О The Boeing Company is headquartered at this building in Chicago, Illinois. Approximately 155,000 people in sixty-seven countries work for Boeing. More than half the company’s employees have college degrees.

bomber. Some of its famous vintage air­planes, such as the B-17 of World War II, are still flown at air shows, while the giant B-52 bomber remains in service with the U. S. Air Force more than fifty years after it first thundered into the skies in 1952.

Boeing’s space and missile develop­ment began with the Bomarc missile in the 1950s. Boeing built the first stage of the Saturn V rocket for the Apollo program as well as the Lunar Roving Vehicle used by Apollo astronauts for exploring the Moon. The company’s current satellite activities include the Sea Launch communications satellite system. Boeing is also actively involved in both the Space Shuttle and the International Space Station programs.

Video images of the vehicle climbing away from the launch pad showed a flame jetting out of the booster where the smoke had been seconds earlier. The flame was like a blowtorch on the bot­tom of the external fuel tank and on one of the metal struts connecting the tank to the solid rocket booster.

Hydrogen started leaking from the tank, feeding the flame. The strut was weakened so much by the heat that it gave way, allowing the booster rocket to swing out of position and collide with the tank. The tank was torn apart, releasing a massive amount of liquid hydrogen and then liquid oxygen.

Just a fraction of a second later, Challenger disappeared in a huge fire­ball. The booster rockets separated from the rest of the vehicle and flew away on their own. They were triggered to self-destruct by a radio signal from the ground. Challenger broke up, and wreck­age rained down into the ocean. It was obvious that the astronauts had perished and there would be no survivors. In the weeks that followed, U. S. Navy divers recovered about a third of the space­craft, half of the solid rocket boosters, and half of the external fuel tank.

A presidential commission was set up to investigate and review the causes of the Challenger accident. The remaining three Space Shuttles (Columbia, Atlantis, and Discovery) were grounded for the next 2 years. Meanwhile, a new Space Shuttle, named Endeavour, was built to replace Challenger.

Challenger’s crew of seven included Christa McAuliffe. She was not a pro­fessional pilot, engineer, or scientist like the other astronauts. McAuliffe was a schoolteacher, and she was to be the first of a series of teachers to go into space as part of the Teacher in Space program. Students all over the world were to see her teach science from orbit. The program was suspend­ed after the accident until August 2007, when teacher Barbara Morgan (who had trained with McAuliffe) went into space on STS-118.

The other crew members who died on Challenger were:

• Commander: Francis R. Scobee.

• Pilot: Michael J. Smith.

• Mission Specialist: Judith A. Resnick.

• Mission Specialist: Ellison S. Onizuka.

• Mission Specialist: Ronald E. McNair.

• Payload Specialist: Gregory B. Jarvis.

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Date of birth: May 21, 1878.

Place of birth: Hammondsport,

New York.

Died: July 23, 1930.

Major contributions: Aviation pioneer; built the world’s first seaplane.

lenn Curtiss showed a knack as a mechanic and a taste for speed at an early age. As a young child, Curtiss raced other children on bicycles in his town. He opened a bicycle repair shop at age seventeen and also began working with engines. Soon after, he built his first motorcycle. In 1902 he formed a new company to produce motorcycles in large numbers. At the same time, he began racing them, win­ning several different championships and setting speed records. People called him “the fastest man alive.”

Curtiss’s motorcycle engines were light and powerful, making them perfect for aircraft. Hearing of Curtiss’s success with motorcycles, pioneer balloonist Thomas Baldwin asked him to develop an engine for an airship he was building. Going aloft with Baldwin, Curtiss devel­oped an interest in flying.

In 1907 Alexander Graham Bell – inventor of the telephone—and others formed a new group, called the National Aerial Experiment Association, to build airplanes. They hired Curtiss. In 1908 Curtiss and his crew produced a small plane called the June Bug. With Curtiss flying it, the June Bug won a contest to become the first American airplane to travel 1 kilometer (0.6 miles)—in fact, Curtiss flew twice the required distance. The next year, Curtiss won another American race with a new airplane. In the late summer of 1909, in Reims, France, he won several competitions, enhancing his reputation.

Curtiss gained another triumph in 1910. The New York World newspaper was offering a $10,000 prize to the first pilot to fly from Albany, New York, down the Hudson River to New York City within a day. Curtiss successfully performed the feat, winning the money and even more acclaim.

Curtiss faced a different challenge in 1911: to produce a working seaplane. He placed a long float under the fuselage of an airplane as well as smaller ones under each wing. The plane had wheels so it also could be land-based. The wheels were retractable—the first time

this feature appeared on an aircraft. Curtiss built the seaplane for the U. S. Navy and demonstrated it successfully several times in 1911.

In 1912 Curtiss produced a successful flying boat. Like a regular seaplane, a flying boat can be landed on water. Instead of using floats, however, it lands on the fuselage itself.

Curtiss began building airplanes that the U. S. Army and Navy bought as trainers. Each had two cockpits and two sets of controls, so an experienced pilot could take over if a trainee encountered problems. The most well-known of these trainers was the Jenny, which became the standard military trainer during World War I. It was also popular with stunt pilots after the war.

During the 1920s Curtiss continued to build new designs. He also became interested in developing real estate in the Miami, Florida, area. He continued working until his death in 1930.

Curtiss met Orville and Wilbur Wright in the summer of 1906. At the time his only aviation work had been with air­ships. Since the Wrights did not see Curtiss as a rival, they were more open with him than usual. Later, when Curtiss was working on airplanes, the Wrights came to think that he had stolen ideas from them. They sued him, and the case stayed in the courts until World War I.

At that time, the government forced all aircraft companies to pool their patents in the interests of national security. As a result, the case no longer mattered. Years later, the Curtiss and Wright com­panies merged and became one.

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SEE ALSO:

• Airship • Flying Boat and Seaplane

• Landing Gear • Wright, Orville and Wilbur

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Date of birth: March 14, 1879.

Place of birth: Wurttemberg, Germany. Died: April 18, 1955.

Major contribution: Developed general and special theories of relativity, explaining the motion of bodies in space and time.

Awards: Nobel Prize in Physics; Copley Medal of the Royal Society of London, United Kingdom; Gold Medal of the Royal Astronomical Society, United Kingdom; Franklin Medal of the Franklin Institute, Philadelphia; Max-Planck Medal of the German Physical Society; honors from many universities and other institutions.

lbert Einstein became interested in science and mathematics as a child. Although brilliant, Einstein was not a good student. He had little patience for learning by memoriza­tion, which was the common method of education at the time. At sixteen, he dropped out of school for a while. Later, at university in Switzerland, he angered his professors by skipping classes so he could focus on his own ideas.

Einstein earned a teacher’s diploma in 1901, but he could not find a teach­ing job. His situation continued to wors­en for two years, until a family friend found Einstein employment in the patent office in Bern, Switzerland. The job gave Einstein an income. Because it was not demanding, it also gave him time to think about theoretical problems.

In 1905, Einstein published several scientific papers. One set forth his Special Theory of Relativity. Another offered his famous equation E=mc2 (that is, energy is equal to the mass of an object times the speed of light squared). Einstein said that an object cannot move as fast as the speed of light, although it can near that speed. The closer it gets to that speed, the slower time passes for that object from the perspective of someone who is standing still.

In 1915 Einstein published another paper explaining his General Theory of Relativity. In this, he stated that time joins the three dimensions of space (height, width, and depth) as a dimen­sion of matter. Matter, Einstein said, exists in “space-time,” and gravitation is a bending of space-time that pulls objects toward each other. He proposed that the curvature of space-time would cause light to be bent around the Sun.

Einstein’s ideas were not widely accepted at first. In 1919, however, sci­entists found that the light from stars did bend around the Sun, as Einstein had suggested. Immediately, he was hailed as a genius.

Einstein became one of the most famous scientists of his age. He gave lectures and speeches around the world. By the early 1930s, however, Germany— where Einstein then lived—was no longer safe. Adolf Hitler and his Nazi Party were growing in power and began persecuting Jews. Einstein, who was a Jew, left Germany in 1932. He settled in Princeton, New Jersey.

As the 1930s progressed,

Hitler gained more power in Germany and began to rebuild the nation’s armed forces. Meanwhile, scien­tists there and in other countries began using the theories of Einstein and other physicists to develop a powerful new weapon: the atomic bomb. In 1939 Einstein wrote a letter to the U. S. president, Franklin D. Roosevelt, warning him that the Germans were making progress in this work. He urged Roosevelt to undertake a crash program to develop such a weapon.

As a result, the Manhattan Project was launched. The huge U. S. project produced the world’s first atomic weapons, which were used in 1945 on two Japanese cities in a devasting-and suc­cessful-attempt to persuade Japan to surrender. The bombings brought an end to World War II.

Einstein spent the rest of his years in pursuit of two causes. One was peace. Although he had supported the fight against Hitler during World War II, Einstein was generally a pacifist. The other was an attempt to develop a unified field theory in physics-that is, Einstein hoped to explain how the major theories in physics could all be united in one single idea. He was unable to
achieve this goal before his death. Even today, physicists still wrestle with the problem.

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SEE ALSO:

• Energy • Force • Gravity

• Newton, Isaac • Relativity,

Theory of

In the last few months of World War II, the first jet fighter, the German Me-262, zoomed into combat. Much faster than any Allied propeller plane, it was power­fully armed with a 30-millimeter gun and rockets. Fortunately, the Me-262 was not used effectively-most Me-262s were used to carry bombs, and a bomb load reduced its speed. The Germans devel­
oped other jet airplanes and the rocket – powered Me-163, which was designed to intercept high-flying Allied bombers.

The only Allied jet to see combat in World War II was the British Meteor, a twin-engine fighter fast enough to destroy German V-1 flying bombs. The first U. S. jet in service, the XP-80 Shooting Star, was built in just 143 days and first flew in January 1944. Too late to fight in World War II, it saw combat in 1950 during the Korean War.

After World War II, it was clear that propeller-driven, piston-engine fighters were obsolete. Air forces hastened to equip themselves with jets, which were armed with missiles rather than machine guns. The U. S. Air Force had its first swept-wing fighter, the F-86 Sabre, in

1947 and its first all-weather interceptor, the F-94 Starfire, in 1949.

Jet fighters flew in combat during the Korean War, and the first victory gained in an all-jet air combat came in 1950 when Lieutenant Russell J. Brown, Jr., flying an F-80, shot down a Chinese MiG-15 fighter. Jet fighters also demon­strated their ability to fly nonstop across the ocean, when in 1950 an F-84 Thunderjet flew from Britain to the United States, refueling in the air three times on the way.

STEALTH

Although the F in the F-117 Nighthawk’s name designates it as a fighter, the stealth aircraft is a primarily a ground attack plane. Developed in secret, the F-117 became operational in 1983. Its unusual shape and construction help "blind" an enemy’s radar. It relies on stealth, not speed, to surprise an enemy. The Nighthawk has been used in war­fare by the United States in Panama in 1989, in the 1991 Gulf War, and in Iraq.

A Key Role

In the 1950s, some experts believed mis­siles could replace fighters. Experience in later conflicts (Vietnam, the Gulf War, Bosnia, and Iraq) has shown that the fighter plane still has a key role. Its tasks are now varied: Besides fighting enemy airplanes, it also flies reconnaissance, electronic warfare, and strike missions.

Over time, the fighter pilot’s job has become technically and physically more demanding. Some planes, such as the Russian MiG-31, need a second crew member to operate the weapons systems. The Russian MiG family of warplanes is one of the most famous in aviation history. It began with the Mikoyan – Gurevich MiG-1, a propeller-driven fighter of 1940. The MiG-15 jet (1950) was followed by a succession of faster MiGs, including the MiG-25, which set speed and altitude records. MiG fighters led the air forces of many Communist nations in Eastern Europe during the Cold War, and these fighter planes also were built in Chinese versions.

For many people, long-distance flying is a tedious ordeal, not a pleasure. Airplane designers of the future may make flying more comfortable by fitting fewer, big­ger seats, maybe arranged diagonally instead of in rows. Larger airplanes with fewer seats would offer passengers the chance to stretch their legs during the flight. Passengers should be able to surf the Internet on a laptop (Internet access on airlines was approved by the FAA in 2005). They may even be able to order meals and drinks from a virtual flight attendant who pops up onscreen at the click of a button or mouse.

In the twenty-first century, air travel will feature a mix of aircraft types: large- and medium-size, very fast and relatively slow, and some with VSTOL (vertical/short takeoff and landing) capability. There might be a return to

Designs for supersonic aircraft of the future include HyperSoar, a large air­plane flying at Mach 10, or 6,700 miles per hour (10,780 kilometers per hour). A major problem at such hypersonic speeds is heat from fric­tion. HyperSoar is designed to avoid this problem by skipping along the upper edge of the atmosphere, just as a flat rock skims when thrown across a pond. It would climb to 210,000 feet (64,000 meters), then turn off its engine and descend to 105,000 feet (32,000 meters). The engine would be turned back on again, and HyperSoar would skip back up to the fringes of space. It would repeat the process until it landed like a normal airplane.

HyperSoar also could become the first stage of a two-stage launch sys­tem for space satellites.

Fast flight times are still regarded as a key selling point for some new airplanes. Experts are not sure how passengers would react to the skip­ping motion of HyperSoar (it might feel like a giant theme park ride), but the flight would be quick. Allowing for time and distance to take off and land, a HyperSoar flight from Chicago

to Tokyo (just over 6,000 miles, or about 10,000 kilometers) would require twenty-one skips and last 65 to 72 minutes. A cross-country trip from New York City to Los Angeles would need nearly ten skips and be completed in about 35 to 37 minutes.

airships, which have been absent from the skies since the 1930s. Airships are slow, but they give passengers a tranquil view of the scenery below as they glide through the air at around 100 miles per hour (160 kilometers per hour).

Looking farther ahead, the airliner of the future could be a flying wing or blended wing body (BWB). The BWB is a more efficient shape for high-speed flight at altitude. The plane would have no windows. To avoid claustrophobia, passengers would be given a “view”
through artificial windows or on screens of a simulated sky outside. A BWB air­liner could be flying by 2020.

A glider has the same basic shape as a powered airplane, but its wings are longer and very narrow. Narrow wings produce less drag than wide wings. The longer the wings, the more wing area the glider has to generate lift. A competition sailplane may have wings that are 70 feet (21 meters) long but less than 3 feet (1 meter) wide. Just like a powered air­plane, gliders’ wings have ailerons-and sometimes flaps as well-for control in flight. Many gliders carry water as bal­last in the wings. The ballast, which pro­vides additional weight for extra control in fast rising air currents, is jettisoned (dropped) before the glider lands.

The fuselage (or body) of a glider is slim, again to reduce drag. It is often so

slim that the pilot has to lie almost prone in the cockpit. Trainer gliders, designed for two people-an experienced pilot and a student-have slightly wider bodies and cockpits in which the passen­gers can sit upright.

Gliders are made of lightweight materials, usually aluminum, fiberglass, metal, and wood. The outer skin is smoothed and polished to reduce air resistance. Landing gear on a glider usu­ally consists of one landing wheel that folds away after the glider is airborne.

Launching

Most gliders are launched by a towing airplane. A towrope or wire, usually 150-200 feet (46-61 meters) long, is fastened from a hook on the towing

GLIDER CLASSIFICATION

The French Federation Aeronautique Internationale (FAI) is recognized as the world’s air sports association. It classes gliders for competition in various ways.

The classes include:

• Standard class: no flaps, wingspan 49.21 feet (15 meters).

• 15-meter (49.21-feet) class:

flaps allowed.

• 18-meter (59.06-feet) class:

flaps allowed.

• Open class: no restrictions.

• Two-seater class: maximum wingspan 65.62 feet (20 meters).

• Club class: open to a range of types, including older gliders.

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airplane to another hook on the nose of the glider. As the towing airplane takes off, it pulls the glider after it, and the two airplanes gain height. Once a glider has gained sufficient altitude-usually between 2,000 and 3,000 feet (610 and 915 meters)-the glider pilot frees the glider from the towrope by using a con­trol in the cockpit.

Gliders also can be launched by cat­apulting them off hillsides or by towing them behind a vehicle, but the most usual alternative to tow launching is to use a winch. This process is similar to launching a kite. A power-operated winch is set at one end of the takeoff

О The Duo Discus is a high-performance glider used in fast cross-country flying. Built in the Czech Republic, the two-seater used for high-level training and often is seen in competitions.

Powerful air currents, known as mountain waves, are found on the lee (sheltered) side of steep, high mountains. Flying a glider in mountain waves is sometimes called ridge running. A glider also will soar when it flies into a shear line, or convergence zone, where a mass of cool air has forced a block of lighter, warm air to rise. Experienced glider pilots learn to take full advantage of these air currents and other favorable flying conditions.

New records are frequently set by gliders for height, distance, and speed. Gliders have climbed to heights of over

49,0 feet (14,940 meters) and have made straight-line flights of more than 1,240 miles (1,995 kilometers).

A glider pilot has four basic flying instruments: an airspeed indicator, an altimeter (to show altitude), a compass, and a vario/altimeter that indicates the rate at which the plane is rising or falling. The vario/altimeter helps the pilot determine the glider’s position in relation to nearby rising air currents. The pilot also can use computers and GPS systems to keep track of the air­craft’s position and course.

Using airbrakes to slow its descent, a glider can land on almost any flat field, often miles from its launch. Most are designed to be taken apart so they can be loaded on a trailer for the trip home.

Regulations for glider pilots are simi­lar to those for other airplane pilots. In the United States, the Federal Aviation Administration is responsible for regu­lating pilots and gliders.

SEE ALSO:

• Aerodynamics • Aeronautics

• Cayley, George • Lift and Drag

• Lilienthal, Otto • Wright, Orville

and Wilbur

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