66 résultats pour "launched"

• Mars Climate Orbiter Mars Climate Orbiter, United States spacecraft launched in 1998 to explore the planet Mars.

• Cultural Revolution I INTRODUCTION Cultural Revolution (1966-1976), political campaign in China, launched in 1966 by Chinese Communist Party chairman Mao Zedong to eliminate his political rivals and revolutionize Chinese society.

  1990s attempted to wipe out the legacy of the Cultural Revolution. Even Mao, once glorified as “The Great Helmsman” and the “Red Sun,” was officially criticized for his “leftist mistakes” in the Cultural Revolution, but was still praised forhis leadership in both the war against Japan ( see Sino-Japanese Wars) and the civil war against the Kuomintang. Today, while privately vilified by many Chinese, Mao is at the same time still genuinely admired as a powerful national leader. Contributed By:Rut...

• Space Exploration - astronomy.

  to produce 250,000 newtons (56,000 lb) of thrust. The Germans launched thousands of V-2s carrying explosives against targets in Britain and The Netherlands. Whilethey did not prove to be an effective weapon, V-2s did become the first human-made objects to reach altitudes above 80 km (50 mi)—the height at which outer spaceis considered to begin—before falling back to Earth. The V-2 inaugurated the era of modern rocketry. A2 Early Artificial Satellites During the years following World War II, the...

• Apollo Program - astronomy.

  Moon’s orbit; rendezvousing and docking with the CSM; and finally, setting a course home to Earth. On return to Earth, the spacecraft was slowed by drag from Earth’satmosphere and by parachutes (just before splashdown), before landing in the ocean. The transit time to and from the Moon was approximately three days each way.Depending on the specific mission, the time in lunar orbit ranged from less than one day for Apollo 8 to over six days for the final three missions, and the time on thelunar s...

• Apollo Program - U.

  Moon’s orbit; rendezvousing and docking with the CSM; and finally, setting a course home to Earth. On return to Earth, the spacecraft was slowed by drag from Earth’satmosphere and by parachutes (just before splashdown), before landing in the ocean. The transit time to and from the Moon was approximately three days each way.Depending on the specific mission, the time in lunar orbit ranged from less than one day for Apollo 8 to over six days for the final three missions, and the time on thelunar s...

• Space Shuttle - astronomy.

  The two SRBs, with their combined thrust of some 26 million newtons (about 5.8 million lb), provide most of the power for the first two minutes of flight. The SRBs takethe space shuttle to an altitude of 45 km (28 mi) and a speed of 4,973 km/h (3,094 mph) before they separate and fall back into the ocean to be retrieved,refurbished, and prepared for another flight. After the boosters fall away, the three main engines continue to provide thrust. These engines are clustered at the rear end of the...

• X-Ray Astronomy - astronomy.

  Some neutron stars have weaker magnetic fields that allow incoming material to settle onto the entire surface of the neutron star. Eventually, so much material buildsup that the surface layer becomes dense enough to set off a vast thermonuclear explosion, called an outburst. The explosion heats gas to produce X rays. Such aneutron star—called an X-ray burster—can increase its X-ray production by a million times during an outburst. The X-ray glow fades over time, and the binary systementers a lon...

• Indo-Pakistani Wars - History.

  wrest Jammu and Kashmīr from India through the use of force. This effort failed as India held its ground, and the war ended in a stalemate after almost two months ofarmed conflict. Although the second war over the territory was shorter than the first, the increased firepower of the two nations resulted in a more deadly war, with atotal of about 6,800 battle casualties. A Events Before the War A number of factors precipitated the second conflict over Jammu and Kashm īr. In the wake of a border w...

• SLBM (Submarine Launched Ballistic Missile) , missile stratégique tiré d'un sous-marin.

• Artificial Satellite - astronomy.

  The first stage of a multistage rocket consists of rocket engines that provide a huge amount of force, or thrust. The first stage lifts the entire launch vehicle—with itsload of fuel, the rocket body, and the satellite—off the launch pad and into the first part of the flight. After its engines use all their fuel, the first stage portion of therocket separates from the rest of the launch vehicle and falls to Earth. The second stage then ignites, providing the energy necessary to lift the satellit...

• Dwight D.

  maneuvers in Louisiana in 1941, he played a leading role as a staff officer, adding to his reputation and securing him a promotion to brigadier general. On December 7,1941, Japan attacked Pearl Harbor, Hawaii, and the next day the United States entered World War II against the Axis Powers (Japan, Germany, and Italy). A weeklater, the army’s new chief of staff, General George C. Marshall, called Eisenhower to Washington, D.C., and put him in charge of the War Plans Division. Opinions differed on...

• George Herbert Walker Bush.

  Lebanon. More troubling was the disclosure that agents operating under direct White House supervision used profits from the arms sales to buy weapons for thecontras, a group of anti-government Nicaraguan rebels, despite an explicit congressional ban on such aid. Bush later claimed that he opposed the arms-for-hostagesdeal, but offered little evidence to back his claims ( see Iran-Contra Affair). C 1988 Presidential Election While the Reagan-Bush program helped produce prosperity for the wealth...

• George Herbert Walker Bush - USA History.

  Lebanon. More troubling was the disclosure that agents operating under direct White House supervision used profits from the arms sales to buy weapons for thecontras, a group of anti-government Nicaraguan rebels, despite an explicit congressional ban on such aid. Bush later claimed that he opposed the arms-for-hostagesdeal, but offered little evidence to back his claims ( see Iran-Contra Affair). C 1988 Presidential Election While the Reagan-Bush program helped produce prosperity for the wealth...

• Moon - astronomy.

  B Volcanic Features Maria, domes, rilles, and a few craters display indisputable characteristics of volcanic origin. Maria are plains of dark-colored rock that cover approximately 40 percent ofthe Moon's visible hemisphere. The maria formed when molten rock erupted onto the surface and solidified between 3.16 billion and 3.96 billion years ago. This rockresembles terrestrial basalt, a volcanic rock type widely distributed on Earth, but the rock that formed the maria has a higher iron content an...

• Infrared Astronomy - astronomy.

  ft above sea level. With the launch of the Infrared Astronomical Satellite (IRAS), by the United States, the United Kingdom, and The Netherlands in 1983, infraredastronomy took another leap forward. This mission surveyed the entire sky at wavelengths of 12, 25, 60, and 100 microns (1 micron is a millionth of a meter) until itsonboard supply of liquid helium ran out. A short time later infrared astronomy was revolutionized by the first introduction of devices that could take infrared images. Thea...

• Nicaraguan Revolution.

  Directorate. Within a year Robelo and Violeta Chamorro left the junta, and the Council of State was reorganized to guarantee an overwhelming Sandinista majority.Elections were postponed, restrictions were placed on the media, and relations with the Roman Catholic Church became increasingly tense. Two non-Sandinistasreplaced Robelo and Chamorro on the junta, but they had little power, and the government’s relations with opposition political parties and the private business sectordeteriorated. A D...

• Korean War.

  During the summer of 1949, South Korea had expanded its army to about 90,000 troops, a strength the North matched in early 1950. The North had about 150 SovietT-34 tanks and a small but effective air force of 70 fighters and 62 light bombers—weapons either left behind when Soviet troops evacuated Korea or bought from theUSSR and China in 1949 and 1950. By June 1950 American data showed the two armies at about equal strength, with roughly equal numbers amassed along the 38thparallel. However, thi...

• Korean War - History.

  During the summer of 1949, South Korea had expanded its army to about 90,000 troops, a strength the North matched in early 1950. The North had about 150 SovietT-34 tanks and a small but effective air force of 70 fighters and 62 light bombers—weapons either left behind when Soviet troops evacuated Korea or bought from theUSSR and China in 1949 and 1950. By June 1950 American data showed the two armies at about equal strength, with roughly equal numbers amassed along the 38thparallel. However, thi...

• Korean War - U.

  During the summer of 1949, South Korea had expanded its army to about 90,000 troops, a strength the North matched in early 1950. The North had about 150 SovietT-34 tanks and a small but effective air force of 70 fighters and 62 light bombers—weapons either left behind when Soviet troops evacuated Korea or bought from theUSSR and China in 1949 and 1950. By June 1950 American data showed the two armies at about equal strength, with roughly equal numbers amassed along the 38thparallel. However, thi...

• Epigoni (Descendants, the younger generation) Greek The sons of the Seven Against Thebes, an expedition launched by Adrastus and Polynices to capture the throne of Thebes.

• World War I .

  and troops to Europe from the United States and other overseas sources. In 1914 Britain implemented a sea blockade of Germany to prevent the delivery of importssuch as food and war materials. The same year, Germany began using submarines to disrupt Allied seaborne traffic and prevent supplies from reaching Britain. In 1915Germany instituted a submarine blockade around Britain. From February 1915 to September 1915 and again in 1917, Germany used unrestricted submarine warfare,sinking ships withou...

• NASA - astronomy.

  Challenger shuttle after launch in 1986 and the Columbia shuttle during reentry in 2003, killing both crews. Investigations traced the accidents to design flaws and tomanagement problems. Both accidents led to design and procedure changes, and to a temporary stoppage of shuttle flights. Following the Columbia disaster, NASA alsoannounced plans to retire the shuttle in 2010, after completion of the International Space Station (ISS), a human orbital research facility. The Constellation program is...

• Mao ZedongIINTRODUCTIONMao Zedong (1893-1976), foremost Chinese Communist leader of the 20th century and the principal founder of the People's Republic of China.

  outside the government was also muted because the educated elite remembered the turmoil of the “Hundred Flowers” and “Antirightist” campaigns of 1957. Mao’srelationship with intellectuals was an uneasy one, and he was critical of the gap between the lives of the urban educated elite and the rural masses. These tensions wereamong the underlying causes of the Cultural Revolution, a period of social unrest and political persecution launched by Mao in 1966. Mao mobilized youth into the RedGuards to...

• Mao Zedong.

  outside the government was also muted because the educated elite remembered the turmoil of the “Hundred Flowers” and “Antirightist” campaigns of 1957. Mao’srelationship with intellectuals was an uneasy one, and he was critical of the gap between the lives of the urban educated elite and the rural masses. These tensions wereamong the underlying causes of the Cultural Revolution, a period of social unrest and political persecution launched by Mao in 1966. Mao mobilized youth into the RedGuards to...

• Mao Zedong - History.

  outside the government was also muted because the educated elite remembered the turmoil of the “Hundred Flowers” and “Antirightist” campaigns of 1957. Mao’srelationship with intellectuals was an uneasy one, and he was critical of the gap between the lives of the urban educated elite and the rural masses. These tensions wereamong the underlying causes of the Cultural Revolution, a period of social unrest and political persecution launched by Mao in 1966. Mao mobilized youth into the RedGuards to...

• Kuiper Belt - astronomy.

  III RESEARCH The Kuiper Belt is an exciting area of research in astronomy. The discovery and astronomical exploration of the Kuiper Belt over the past decade have fueled arevolution in scientists’ views of the solar system. Today astronomers recognize the Kuiper Belt as the third major region of the solar system (the other two regions arethe inner solar system, with its small rocky planets, and the outer solar system, with its gas-giant planets). They believe that the belt helps explain Pluto’...

• Big Bang Theory - astronomy.

  hydrogen atoms. Hydrogen atoms can only absorb and emit specific colors, or wavelengths, of light. The formation of atoms allowed many other wavelengths of light,wavelengths that had been interfering with the free electrons prior to the cooling of the universe, to travel much farther than before. This change set free radiation thatwe can detect today. After billions of years of cooling, this cosmic background radiation is at about 3 K (-270°C/-454°F).The cosmic background radiation was first d...

• Louis Stephen St.

  St. Laurent brought to office a new concept of government. His broad, all-national view firmly rejected Québec's traditional isolationism. He made his decisions with coolimpartiality, giving first consideration to the welfare of Canada as a whole. St. Laurent's foreign policy involved Canada in world politics. He supported the UN, fully endorsing the initiatives proposed by Pearson, his representative there. St.Laurent actively sponsored and subsequently cooperated with the North Atlantic Treaty...

• Louis Stephen St.

  St. Laurent brought to office a new concept of government. His broad, all-national view firmly rejected Québec's traditional isolationism. He made his decisions with coolimpartiality, giving first consideration to the welfare of Canada as a whole. St. Laurent's foreign policy involved Canada in world politics. He supported the UN, fully endorsing the initiatives proposed by Pearson, his representative there. St.Laurent actively sponsored and subsequently cooperated with the North Atlantic Treaty...

• Richard Nixon.

  As President Eisenhower neared the end of his second term, his vice president emerged as his logical successor, and the president endorsed Nixon in March. Nixonreceived an impressive vote in party primaries, and at the Republican National Convention, held in Chicago in July, he received all but ten of the delegates’ votes on thefirst ballot. Nixon chose as his running mate the U.S. ambassador to the United Nations, Henry Cabot Lodge of Massachusetts. An unusual feature of the campaign wasa serie...

• Richard Nixon

  As President Eisenhower neared the end of his second term, his vice president emerged as his logical successor, and the president endorsed Nixon in March. Nixonreceived an impressive vote in party primaries, and at the Republican National Convention, held in Chicago in July, he received all but ten of the delegates’ votes on thefirst ballot. Nixon chose as his running mate the U.S. ambassador to the United Nations, Henry Cabot Lodge of Massachusetts. An unusual feature of the campaign wasa serie...

• Mexican Revolution.

  growing economic and social difficulties. Although Madero called for free and democratic elections, and a ban on reelection at all levels of government, he offered little tourban workers seeking higher wages and better working conditions, or to indigenous people seeking the restoration of their traditional lands. Madero’s intention was tolead a political rebellion, not a social revolution. Despite the political nature of the plan, it became a rallying point for poor and working-class Mexicans, m...

• Wars of Yugoslav Succession.

  of Yugoslav succession was over. In January 1992 members of the European Community (EC; after 1993 the European Union, EU) recognized Slovenia’s independencealong with that of Croatia. The United States and other countries did so shortly thereafter. IV THE WAR IN CROATIA As the Yugoslav army withdrew from Slovenia in July 1991, a second and far more serious conflict erupted in Croatia. But the road to war in Croatia began more than ayear earlier. In April and May 1990 the Croatian Democratic U...

• Wars of Yugoslav Succession .

  of Yugoslav succession was over. In January 1992 members of the European Community (EC; after 1993 the European Union, EU) recognized Slovenia’s independencealong with that of Croatia. The United States and other countries did so shortly thereafter. IV THE WAR IN CROATIA As the Yugoslav army withdrew from Slovenia in July 1991, a second and far more serious conflict erupted in Croatia. But the road to war in Croatia began more than ayear earlier. In April and May 1990 the Croatian Democratic U...

• Québec - Geography.

  facilities. Tributaries south of the St. Lawrence include the Richelieu, the Saint-François, and the Chaudière rivers, which are only a few hundred kilometers long. TheRimouski and Matane rivers, also south of the St. Lawrence, are popular areas for recreation and salmon fishing. In the Canadian Shield, the longest rivers are theRupert, Eastmain, Grande Baleine, and La Grand-Rivière, which is the site of a huge hydroelectric complex. C Coastlines Québec has two systems of saltwater coastline. O...

• Québec - Canadian History.

  facilities. Tributaries south of the St. Lawrence include the Richelieu, the Saint-François, and the Chaudière rivers, which are only a few hundred kilometers long. TheRimouski and Matane rivers, also south of the St. Lawrence, are popular areas for recreation and salmon fishing. In the Canadian Shield, the longest rivers are theRupert, Eastmain, Grande Baleine, and La Grand-Rivière, which is the site of a huge hydroelectric complex. C Coastlines Québec has two systems of saltwater coastline. O...

• European Space Agency - astronomy.

• Ranger (spacecraft) - astronomy.

• Mariner - astronomy.

• Salyut - astronomy.

  Contributed By:David S. F. PortreeMicrosoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.

• Saturn (rocket) - astronomy.

• Luna (space program) - astronomy.

• Surveyor (spacecraft) - astronomy.

• Vostok Program - astronomy.

  At almost five days in duration, Vostok 5 remains the longest solo space mission ever. Valeri Bykovskii flew alone for 81 orbits and 3 million km (2 million mi) from June14 to June 19, 1963. Valentina Tereshkova became the first woman in space when she flew aboard Vostok 6 from June 16 to June 19, 1963. On its first orbit, Vostok 6passed within 5 km (3 mi) of Vostok 5. Tereshkova flew on for 2 days 22 hours, covering 1.9 million km (1.2 million mi) in 48 orbits. Soviet engineers planned a Vostok...

• Space Station - astronomy.

• Mercury Program - astronomy.

• Rocket.

  the vacuum of space, however, demonstrated that this belief was not true. In fact, rockets produce more thrust in the vacuum of space than on Earth. Air pressure andfriction with the air reduce a rocket’s thrust by about 10 percent on Earth as compared to the rocket’s performance in space. B Thrust and Efficiency Thrust is a measurement of the force of a rocket, or the amount of “push” exerted backward to move a rocket forward. Thrusts vary greatly from rocket to rocket.Engineers measure thrust...

• Rocket - astronomy.

  the vacuum of space, however, demonstrated that this belief was not true. In fact, rockets produce more thrust in the vacuum of space than on Earth. Air pressure andfriction with the air reduce a rocket’s thrust by about 10 percent on Earth as compared to the rocket’s performance in space. B Thrust and Efficiency Thrust is a measurement of the force of a rocket, or the amount of “push” exerted backward to move a rocket forward. Thrusts vary greatly from rocket to rocket.Engineers measure thrust...

• Pioneer (spacecraft) - astronomy.

  The Pioneer Venus spacecraft contributed a tremendous amount of new information about Venus. Venus showed an enormous difference between night (-170°C, or -274°F) and day (40°C, or 104°F) temperatures in the highest regions of the atmosphere (the thermosphere during the day and the cryosphere at night) at altitudesbetween 130 and 200 km (between 81 and 120 mi). Below the clouds was a region of constantly high temperature and pressure and almost no wind. The Pioneer Venuscraft found the clouds ar...

• Mars (planet) - astronomy.

  The Martian core is probably much like Earth’s, consisting mostly of iron, with a small amount of nickel. If other light elements, particularly sulfur, exist there as well, thecore may be larger than presently thought. From studying Earth’s magnetic field and core, scientists theorize that the motions of the liquid rock in Earth’s core generateits magnetic field. Mars does not have a significant magnetic field, so scientists believe that Mars’s core is probably solid. However, spacecraft data in...