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111-515: The GEOStar-3 is a communications satellite spacecraft model made by Northrop Grumman Innovation Systems . GEOStar-3 represents an evolutionary growth from Northrop Grumman Innovation Systems GEOStar-2 platform. The GEOStar-3 Bus can accommodate payloads of up to 800 kilograms and 8,000 watts. Some changes to the GEOStar-3 bus include increased battery capacity and solar array power, enabling it to provide up to eight kilowatts of power to

222-495: A cascading waterfall with Italian Renaissance -style architecture. Modern , Postmodern , contemporary , and other non-classical architectural styles are also seen in the city. The National Museum of African American History and Culture deeply contrasts the stone-based neoclassical buildings on the National Mall with a design that combines modern engineering with heavy inspiration from African art . The interior of

333-486: A 2023 population of 6.3 million residents. A locally elected mayor and 13-member council have governed the district since 1973, though Congress retains the power to overturn local laws. Washington, D.C., residents are, on the federal level, politically disenfranchised since the city's residents do not have voting representation in Congress; the city's residents elect a single non-voting congressional delegate to

444-487: A center of the nation's internal slave trade . After its survey, the new federal city was constructed on the north bank of the Potomac River, to the east of Georgetown centered on Capitol Hill . On September 9, 1791, three commissioners overseeing the capital's construction named the city in honor of President Washington. The same day, the federal district was named Columbia, a feminine form of Columbus , which

555-455: A data network aiming to provide a „Lunar Internet for cis-lunar spacecraft and Installations. The Moonlight Initiative is an equivalent ESA project that is stated to be compatible and providing navigational services for the lunar surface. Both programmes are satellite constellstions of several satellites in various orbits around the Moon. Other orbits are also planned to be used. Positions in

666-469: A federal town". In Federalist No. 43 , published January 23, 1788, James Madison argued that the new federal government would need authority over a national capital to provide for its own maintenance and safety. The Pennsylvania Mutiny of 1783 emphasized the need for the national government not to rely on any state for its own security. Article One, Section Eight of the Constitution permits

777-408: A garden-lined grand avenue about 1 mile (1.6 km) long and 400 feet (120 m) wide in an area that is now the National Mall inspired by the grounds at Versailles and Tuileries Gardens. In March 1792, President Washington dismissed L'Enfant due to conflicts with the three commissioners appointed to supervise the capital's construction. Andrew Ellicott , who worked with L'Enfant in surveying

888-518: A medium Earth orbit satellite is about 16,000 kilometres (10,000 mi) above Earth. In various patterns, these satellites make the trip around Earth in anywhere from 2 to 8 hours. To an observer on Earth, a satellite in a gestationary orbit appears motionless, in a fixed position in the sky. This is because it revolves around the Earth at Earth's own angular velocity (one revolution per sidereal day , in an equatorial orbit ). A geostationary orbit

999-502: A modern glass exterior and heavy curvature. CityCenterDC is home to Palmer Alley, a pedestrian-only walkway, and houses several apartment buildings, restaurants, and luxury-brand storefronts with streamlined glass and metal facades. Outside Downtown D.C., architectural styles are more varied. Historic buildings are designed primarily in the Queen Anne , Châteauesque , Richardsonian Romanesque , Georgian Revival , Beaux-Arts , and

1110-591: A more precise match for the capabilities of geosynchronous comsats. Two satellite types are used for North American television and radio: Direct broadcast satellite (DBS), and Fixed Service Satellite (FSS). The definitions of FSS and DBS satellites outside of North America, especially in Europe, are a bit more ambiguous. Most satellites used for direct-to-home television in Europe have the same high power output as DBS-class satellites in North America, but use

1221-687: A number of satellites for various purposes; for example, METSAT for meteorological satellite, EUMETSAT for the European branch of the program, and METOP for meteorological operations. These orbits are Sun synchronous, meaning that they cross the equator at the same local time each day. For example, the satellites in the NPOESS (civilian) orbit will cross the equator, going from south to north, at times 1:30 P.M., 5:30 P.M., and 9:30 P.M. There are plans and initiatives to bring dedicated communications satellite beyond geostationary orbits. NASA proposed LunaNet as

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1332-621: A period (time to revolve around the Earth) of about 90 minutes. Because of their low altitude, these satellites are only visible from within a radius of roughly 1,000 kilometres (620 mi) from the sub-satellite point. In addition, satellites in low Earth orbit change their position relative to the ground position quickly. So even for local applications, many satellites are needed if the mission requires uninterrupted connectivity. Low-Earth-orbiting satellites are less expensive to launch into orbit than geostationary satellites and, due to proximity to

1443-545: A radio signal to a telephone system. In this example, almost any type of satellite can be used. Satellite phones connect directly to a constellation of either geostationary or low-Earth-orbit satellites. Calls are then forwarded to a satellite teleport connected to the Public Switched Telephone Network . As television became the main market, its demand for simultaneous delivery of relatively few signals of large bandwidth to many receivers being

1554-431: A relatively high homelessness rate, despite its high living standard compared to many American cities. Washington, D.C., is divided into four quadrants of unequal area: Northwest (NW) , Northeast (NE) , Southeast (SE) , and Southwest (SW) . The axes bounding the quadrants radiate from the U.S. Capitol. All road names include the quadrant abbreviation to indicate their location. House numbers generally correspond with

1665-595: A snowstorm in January 1772. Hurricanes or their remnants occasionally impact the area in late summer and early fall. However, they usually are weak by the time they reach Washington, partly due to the city's inland location. Flooding of the Potomac River , however, caused by a combination of high tide, storm surge, and runoff, has been known to cause extensive property damage in the Georgetown neighborhood of

1776-676: A special committee charged with beautifying Washington's ceremonial core. What became known as the McMillan Plan was finalized in 1901 and included relandscaping the Capitol grounds and the National Mall, clearing slums, and establishing a new citywide park system. The plan is thought to have largely preserved L'Enfant's intended design for the city. By law, the city's skyline is low and sprawling. The federal Height of Buildings Act of 1910 prohibits buildings with height exceeding

1887-468: A tactical necessity, and the ultimate goal of this project was the creation of the longest communications circuit in human history, with the Moon, Earth's natural satellite, acting as a passive relay. After achieving the first transoceanic communication between Washington, D.C. , and Hawaii on 23 January 1956, this system was publicly inaugurated and put into formal production in January 1960. The first satellite purpose-built to actively relay communications

1998-473: A variety of Victorian styles. Rowhouses are prominent in areas developed after the Civil War and typically follow Federal and late Victorian designs. Georgetown 's Old Stone House , built in 1765, is the oldest-standing building in the city. Founded in 1789, Georgetown University features a mix of Romanesque and Gothic Revival architecture . The Ronald Reagan Building is the largest building in

2109-553: Is also possible to offer discontinuous coverage using a low-Earth-orbit satellite capable of storing data received while passing over one part of Earth and transmitting it later while passing over another part. This will be the case with the CASCADE system of Canada's CASSIOPE communications satellite. Another system using this store and forward method is Orbcomm . A medium Earth orbit is a satellite in orbit somewhere between 2,000 and 35,786 kilometres (1,243 and 22,236 mi) above

2220-565: Is carried out under the auspices of the International Telecommunication Union (ITU). To facilitate frequency planning, the world is divided into three regions: Within these regions, frequency bands are allocated to various satellite services, although a given service may be allocated different frequency bands in different regions. Some of the services provided by satellites are: The first and historically most important application for communication satellites

2331-911: Is generally popular among tourists and locals. In 2007, six of the top ten buildings in the American Institute of Architects ' ranking of America's Favorite Architecture were in the city: the White House , Washington National Cathedral , the Jefferson Memorial , the United States Capitol , the Lincoln Memorial , and the Vietnam Veterans Memorial . The neoclassical , Georgian , Gothic , and Modern styles are reflected among these six structures and many other prominent edifices in

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2442-492: Is highly inclined, guaranteeing good elevation over selected positions during the northern portion of the orbit. (Elevation is the extent of the satellite's position above the horizon. Thus, a satellite at the horizon has zero elevation and a satellite directly overhead has elevation of 90 degrees.) The Molniya orbit is designed so that the satellite spends the great majority of its time over the far northern latitudes, during which its ground footprint moves only slightly. Its period

2553-558: Is known as a satellite constellation . Two such constellations, intended to provide satellite phone and low-speed data services, primarily to remote areas, are the Iridium and Globalstar systems. The Iridium system has 66 satellites, which orbital inclination of 86.4° and inter-satellite links provide service availability over the entire surface of Earth. Starlink is a satellite internet constellation operated by SpaceX , that aims for global satellite Internet access coverage. It

2664-576: Is one half day, so that the satellite is available for operation over the targeted region for six to nine hours every second revolution. In this way a constellation of three Molniya satellites (plus in-orbit spares) can provide uninterrupted coverage. The first satellite of the Molniya series was launched on 23 April 1965 and was used for experimental transmission of TV signals from a Moscow uplink station to downlink stations located in Siberia and

2775-410: Is that a MEO satellite's distance gives it a longer time delay and weaker signal than a LEO satellite, although these limitations are not as severe as those of a GEO satellite. Like LEOs, these satellites do not maintain a stationary distance from the Earth. This is in contrast to the geostationary orbit, where satellites are always 35,786 kilometres (22,236 mi) from Earth. Typically the orbit of

2886-485: Is useful for communications because ground antennas can be aimed at the satellite without their having to track the satellite's motion. This is relatively inexpensive. In applications that require many ground antennas, such as DirecTV distribution, the savings in ground equipment can more than outweigh the cost and complexity of placing a satellite into orbit. By 2000, Hughes Space and Communications (now Boeing Satellite Development Center ) had built nearly 40 percent of

2997-501: Is water. The district is bordered by Montgomery County, Maryland , to the northwest; Prince George's County, Maryland , to the east; Arlington County, Virginia , to the west; and Alexandria, Virginia , to the south. The south bank of the Potomac River forms the district's border with Virginia and has two major tributaries, the Anacostia River and Rock Creek . Tiber Creek , a natural watercourse that once passed through

3108-633: The American Civil War in 1861 led to the expansion of the federal government and notable growth in the city's population, including a large influx of freed slaves. President Abraham Lincoln signed the Compensated Emancipation Act in 1862, which ended slavery in the district, freeing about 3,100 slaves in the district nine months before the Emancipation Proclamation . In 1868, Congress granted

3219-435: The Anacostia River to the east. Washington, D.C.'s street grid was extended, where possible, throughout the district starting in 1888. Georgetown's streets were renamed in 1895. Some streets are particularly noteworthy, including Pennsylvania Avenue , which connects the White House to the Capitol; and K Street, which houses the offices of many lobbying groups. Constitution Avenue and Independence Avenue , located on

3330-544: The Chesapeake and Ohio Canal National Historical Park , the National Mall and Memorial Parks , Theodore Roosevelt Island , Columbia Island , Fort Dupont Park , Meridian Hill Park , Kenilworth Park and Aquatic Gardens , and Anacostia Park . The District of Columbia Department of Parks and Recreation maintains the city's 900 acres (3.6 km ) of athletic fields and playgrounds, 40 swimming pools, and 68 recreation centers. The U.S. Department of Agriculture operates

3441-569: The Earth-Moon-Libration points are also proposed for communication satellites covering the Moon alike communication satellites in geosynchronous orbit cover the Earth. Also, dedicated communication satellites in orbits around Mars supporting different missions on surface and other orbits are considered, such as the Mars Telecommunications Orbiter . Communications Satellites are usually composed of

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3552-584: The House of Representatives in 2021 but was not adopted by the U.S. Senate . To become law it would have to be passed by the Senate and signed by president; it would have renamed the city Washington, Douglas Commonwealth and shrunk the Federal District to about the size of the national mall. Designed in 1791 by Pierre Charles L'Enfant , the city is divided into quadrants , which are centered around

3663-628: The International Monetary Fund , the Organization of American States , and other international organizations. Home to many of the nation's largest industry associations, non-profit organizations, and think tanks , D.C. is known as a lobbying hub, with K Street as the industry center. The city had 20.7 million domestic visitors and 1.2 million international visitors, ranking seventh among U.S. cities as of 2022. The Algonquian -speaking Piscataway people , also known as

3774-536: The National Mall , was fully enclosed underground during the 1870s. The creek also formed a portion of the now-filled Washington City Canal , which allowed passage through the city to the Anacostia River from 1815 until the 1850s. The Chesapeake and Ohio Canal starts in Georgetown and was used during the 19th century to bypass the Little Falls of the Potomac River, located at the northwest edge of

3885-623: The Washington Metro stations and the Hirshhorn Museum and Sculpture Garden are designed with strong influence from the 20th-century Brutalism movement. The Smithsonian Institution Building is built of Seneca red sandstone in the Norman Revival style. The Old Post Office building, located on Pennsylvania Avenue and completed in 1899, was the first building in the city to have a steel frame structure and

3996-607: The White House , the Capitol, the Supreme Court Building , and multiple federal departments and agencies . The city is home to many national monuments and museums , located most prominently on or around the National Mall , including the Jefferson Memorial , the Lincoln Memorial , and the Washington Monument . It hosts 177 foreign embassies and serves as the headquarters for the World Bank ,

4107-545: The 1830s, the district's southern territory of Alexandria declined economically, due in part to its neglect by Congress. Alexandria was a major market in the domestic slave trade and pro-slavery residents feared that abolitionists in Congress would end slavery in the district . Alexandria's citizens petitioned Virginia to retake the land it had donated to form the district, a process known as retrocession . The Virginia General Assembly voted in February 1846, to accept

4218-472: The 446-acre (1.80 km ) United States National Arboretum in Northeast Washington, D.C. Washington's climate is humid subtropical ( Köppen : Cfa ), or oceanic ( Trewartha : Do bordering Cf downtown). Winters are cool to cold with some snow of varying intensity, while summers are hot and humid. The district is in plant hardiness zone 8a near downtown, and zone 7b elsewhere in

4329-535: The 9,122 acres (36.92 km ) of city land owned by the U.S. government. Rock Creek Park is a 1,754-acre (7.10 km ) urban forest in Northwest Washington, which extends 9.3 miles (15.0 km) through a stream valley that bisects the city. Established in 1890, it is the country's fourth-oldest national park and is home to a variety of plant and animal species, including raccoon, deer, owls, and coyotes. Other National Park Service properties include

4440-641: The Canadas , the British set fire to government buildings in the city, gutting the United States Capitol , the Treasury Building , and the White House in what became known as the burning of Washington . However, a storm forced the British to evacuate the city after just 24 hours. Most government buildings were repaired quickly, but the Capitol, which was largely under construction at the time, would not be completed in its current form until 1868. In

4551-488: The Capitol Building and include 131 neighborhoods . As of the 2020 census , the city had a population of 689,545. Commuters from the city's Maryland and Virginia suburbs raise the city's daytime population to more than one million during the workweek. The Washington metropolitan area , which includes parts of Maryland, Virginia, and West Virginia , is the country's seventh-largest metropolitan area , with

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4662-513: The City of Washington in 1895. However, the city had poor housing and strained public works, leading it to become the first city in the nation to undergo urban renewal projects as part of the City Beautiful movement in the early 20th century. The City Beautiful movement built heavily upon the already-implemented L'Enfant Plan , with the new McMillan Plan leading urban development in

4773-521: The Conoy, inhabited the lands around the Potomac River and present-day Washington, D.C., when Europeans first arrived and colonized the region in the early 17th century. The Nacotchtank , also called the Nacostines by Catholic missionaries , maintained settlements around the Anacostia River in present-day Washington, D.C. Conflicts with European colonists and neighboring tribes ultimately displaced

4884-423: The Earth faster, they do not remain visible in the sky to a fixed point on Earth continually like a geostationary satellite, but appear to a ground observer to cross the sky and "set" when they go behind the Earth beyond the visible horizon. Therefore, to provide continuous communications capability with these lower orbits requires a larger number of satellites, so that one of these satellites will always be visible in

4995-415: The Earth's surface. MEO satellites are similar to LEO satellites in functionality. MEO satellites are visible for much longer periods of time than LEO satellites, usually between 2 and 8 hours. MEO satellites have a larger coverage area than LEO satellites. A MEO satellite's longer duration of visibility and wider footprint means fewer satellites are needed in a MEO network than a LEO network. One disadvantage

5106-625: The K u band. The Intelsat Americas 5 , Galaxy 10R and AMC 3 satellites over North America provide a quite large amount of FTA channels on their K u band transponders . Washington, D.C. Washington, D.C. , formally the District of Columbia and commonly known as Washington or D.C. , is the capital city and federal district of the United States . The city is on the Potomac River , across from Virginia , and shares land borders with Maryland to its north and east. It

5217-765: The Lincoln Laboratory on behalf of the United States Department of Defense . The LES-1 active communications satellite was launched on 11 February 1965 to explore the feasibility of active solid-state X band long-range military communications. A total of nine satellites were launched between 1965 and 1976 as part of this series. In the United States, 1962 saw the creation of the Communications Satellite Corporation (COMSAT) private corporation, which

5328-645: The Piscataway people, some of whom established a new settlement in 1699 near Point of Rocks, Maryland . Nine cities served as capitals to the Continental Congress and under the Articles of Confederation . New York City was the first capital upon the adoption of the Constitution , succeeded by Philadelphia , which was capital from 1790 to 1800. On October 6, 1783, after the capital

5439-800: The Russian Far East, in Norilsk , Khabarovsk , Magadan and Vladivostok . In November 1967 Soviet engineers created a unique system of national TV network of satellite television , called Orbita , that was based on Molniya satellites. In the United States, the National Polar-orbiting Operational Environmental Satellite System (NPOESS) was established in 1994 to consolidate the polar satellite operations of NASA (National Aeronautics and Space Administration) NOAA (National Oceanic and Atmospheric Administration). NPOESS manages

5550-542: The U.S. House of Representatives. The city's voters choose three presidential electors in accordance with the Twenty-third Amendment , passed in 1961. Washington, D.C. anchors the southern end of the Northeast megalopolis . As the seat of the U.S. federal government , the city is an important world political capital . The city hosts the buildings that house federal government headquarters, including

5661-504: The area. Blizzards affect Washington once every four to six years on average. The most violent storms, known as nor'easters , often impact large regions of the East Coast . From January 27 to 28, 1922 , the city officially received 28 inches (71 cm) of snowfall, the largest snowstorm since official measurements began in 1885. According to notes kept at the time, the city received between 30 and 36 inches (76 and 91 cm) from

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5772-592: The borders of the federal district and placed boundary stones at every mile point; many of these stones are still standing. Both Maryland and Virginia were slave states , and slavery existed in the District from its founding. The building of Washington likely relied in significant part on slave labor, and slave receipts have been found for the White House, Capitol Building, and establishment of Georgetown University. The city became an important slave market and

5883-462: The city , primarily in the U ;Street, 14th Street, 7th Street, and H Street corridors, which were predominantly black residential and commercial areas. The riots raged for three days until more than 13,600 federal troops and Washington, D.C., Army National Guardsmen stopped the violence. Many stores and other buildings were burned, and rebuilding from the riots was not completed until

5994-480: The city at the Atlantic Seaboard fall line . The highest natural elevation in the district is 409 feet (125 m) above sea level at Fort Reno Park in upper northwest Washington, D.C. The lowest point is sea level at the Potomac River. The geographic center of Washington is near the intersection of 4th and L streets NW. The district has 7,464 acres (30.21 km ) of parkland, about 19% of

6105-490: The city but bankrupted its government. In 1874, Congress replaced the territorial government with an appointed three-member board of commissioners. In 1888, the city's first motorized streetcars began service. Their introduction generated growth in areas of the district beyond the City of Washington's original boundaries, leading to an expansion of the district over the next few decades. Georgetown's street grid and other administrative details were formally merged with those of

6216-819: The city throughout the movement. Much of the old Victorian Mall was replaced with modern Neoclassical and Beaux-Arts architecture ; these designs are still prevalent in the city's governmental buildings today. Increased federal spending under the New Deal in the 1930s led to the construction of new government buildings, memorials, and museums in the district, though the chairman of the House Subcommittee on District Appropriations, Ross A. Collins of Mississippi , justified cuts to funds for welfare and education for local residents by saying that "my constituents wouldn't stand for spending money on niggers." World War II led to an expansion of federal employees in

6327-730: The city's classical-style architecture include buildings constructed in the French Second Empire style, including the Eisenhower Executive Office Building , and the modernist Watergate complex . The Thomas Jefferson Building , the main Library of Congress building, and the historic Willard Hotel are built in Beaux-Arts style , popular throughout the world in the late nineteenth and early twentieth centuries. Meridian Hill Park contains

6438-416: The city's total area, the second-highest among high-density U.S. cities after Philadelphia . The city's sizable parkland was a factor in the city being ranked as third in the nation for park access and quality in the 2018 ParkScore ranking of the park systems of the nation's 100 most populous cities, according to Trust for Public Land , a non-profit organization. The National Park Service manages most of

6549-421: The city, was then tasked with completing its design. Though Ellicott revised the original L'Enfant plans, including changing some street patterns, L'Enfant is still credited with the city's overall design. By the early 20th century, however, L'Enfant's vision of a grand national capital was marred by slums and randomly placed buildings in the city, including a railroad station on the National Mall. Congress formed

6660-408: The city. Summers are hot and humid with a July daily average of 79.8 °F (26.6 °C) and average daily relative humidity around 66%, which can cause moderate personal discomfort. Heat indices regularly approach 100 °F (38 °C) at the height of summer. The combination of heat and humidity in the summer brings very frequent thunderstorms, some of which occasionally produce tornadoes in

6771-530: The city. Many of the government buildings, monuments, and museums along the National Mall and surrounding areas are heavily inspired by classical Roman and Greek architecture. The designs of the White House, the U.S. Capitol, Supreme Court Building , Washington Monument , National Gallery of Art , Lincoln Memorial, and Jefferson Memorial are all heavily drawn from these classical architectural movements and feature large pediments, domes, columns in classical order, and heavy stone walls. Notable exceptions to

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6882-469: The city. Precipitation occurs throughout the year. The highest recorded temperature was 106 °F (41 °C) on August 6, 1918, and on July 20, 1930. The lowest recorded temperature was −15 °F (−26 °C) on February 11, 1899 , right before the Great Blizzard of 1899 . During a typical year, the city averages about 37 days at or above 90 °F (32 °C) and 64 nights at or below

6993-680: The city; by 1950, the district's population reached its peak of 802,178 residents. The Twenty-third Amendment to the United States Constitution was ratified in 1961, granting the district three votes in the Electoral College for the election of president and vice president, but still not affording the city's residents representation in Congress. After the assassination of civil rights leader Martin Luther King Jr. on April 4, 1968, riots broke out in

7104-403: The completion of a fully global network with Intelsat 3 in 1969–70. By the 1980s, with significant expansions in commercial satellite capacity, Intelsat was on its way to become part of the competitive private telecommunications industry, and had started to get competition from the likes of PanAmSat in the United States, which, ironically, was then bought by its archrival in 2005. When Intelsat

7215-405: The creation of the capital district along the Potomac River. The city was founded in 1791, and the 6th Congress held the first session in the unfinished Capitol Building in 1800 after the capital moved from Philadelphia . In 1801, the District of Columbia, formerly part of Maryland and Virginia and including the existing settlements of Georgetown and Alexandria , was officially recognized as

7326-462: The curve of the Earth. The purpose of communications satellites is to relay the signal around the curve of the Earth allowing communication between widely separated geographical points. Communications satellites use a wide range of radio and microwave frequencies . To avoid signal interference, international organizations have regulations for which frequency ranges or "bands" certain organizations are allowed to use. This allocation of bands minimizes

7437-619: The dipoles properly separated from each other, the project was able to successfully experiment and communicate using frequencies in the SHF X band spectrum. An immediate antecedent of the geostationary satellites was the Hughes Aircraft Company 's Syncom 2 , launched on 26 July 1963. Syncom 2 was the first communications satellite in a geosynchronous orbit . It revolved around the Earth once per day at constant speed, but because it still had north–south motion, special equipment

7548-486: The district's African American male residents the right to vote in municipal elections. By 1870, the district's population had grown 75% in a decade to nearly 132,000 people, yet the city still lacked paved roads and basic sanitation. Some members of Congress suggested moving the capital farther west, but President Ulysses S. Grant refused to consider the proposal. In the Organic Act of 1871 , Congress repealed

7659-658: The east and north of the Potomac and the County of Alexandria to the west and south. After the Act's passage, citizens in the district were no longer considered residents of Maryland or Virginia, which ended their representation in Congress. On August 24, 1814, during the War of 1812 , British forces invaded and occupied the city after defeating an American force at Bladensburg . In retaliation for acts of destruction by American troops in

7770-455: The edges of Antarctica and Greenland . Other land use for satellite phones are rigs at sea, a backup for hospitals, military, and recreation. Ships at sea, as well as planes, often use satellite phones. Satellite phone systems can be accomplished by a number of means. On a large scale, often there will be a local telephone system in an isolated area with a link to the telephone system in a main land area. There are also services that will patch

7881-587: The equator and therefore appear lower on the horizon as the receiver gets farther from the equator. This will cause problems for extreme northerly latitudes, affecting connectivity and causing multipath interference (caused by signals reflecting off the ground and into the ground antenna). Thus, for areas close to the North (and South) Pole, a geostationary satellite may appear below the horizon. Therefore, Molniya orbit satellites have been launched, mainly in Russia, to alleviate this problem. Molniya orbits can be an appealing alternative in such cases. The Molniya orbit

7992-541: The establishment of a "District (not exceeding ten miles square) as may, by cession of particular states, and the acceptance of Congress, become the seat of the government of the United States". However, the constitution does not specify a location for the capital. In the Compromise of 1790 , Madison, Alexander Hamilton , and Thomas Jefferson agreed that the federal government would pay each state's remaining Revolutionary War debts in exchange for establishing

8103-556: The federal district was a square measuring 10 miles (16 km) on each side and totaling 100 square miles (259 km ). Two pre-existing settlements were included in the territory, the port of Georgetown , founded in 1751, and the port city of Alexandria, Virginia , founded in 1749. In 1791 and 1792, a team led by Andrew Ellicott , including Ellicott's brothers Joseph and Benjamin and African American astronomer Benjamin Banneker , whose parents had been enslaved, surveyed

8214-408: The federal district; initially, the city was a separate settlement within the larger district. In 1846, Congress returned the land originally ceded by Virginia , including the city of Alexandria. In 1871, it created a single municipality for the remaining portion of the district. There have been several unsuccessful efforts to make the district into a state since the 1880s; a statehood bill passed

8325-473: The first artificial satellite used for passive relay communications in Echo 1 on 12 August 1960. Echo 1 was an aluminized balloon satellite acting as a passive reflector of microwave signals. Communication signals were bounced off the satellite from one point on Earth to another. This experiment sought to establish the feasibility of worldwide broadcasts of telephone, radio, and television signals. Telstar

8436-412: The first privately sponsored space launch. Another passive relay experiment primarily intended for military communications purposes was Project West Ford , which was led by Massachusetts Institute of Technology 's Lincoln Laboratory . After an initial failure in 1961, a launch on 9 May 1963 dispersed 350 million copper needle dipoles to create a passive reflecting belt. Even though only about half of

8547-684: The first to use electrical wiring in its design. Notable contemporary residential buildings, restaurants, shops, and office buildings in the city include the Wharf on the Southwest Waterfront , Navy Yard along the Anacostia River , and CityCenterDC in Downtown . The Wharf has seen the construction of several high-rise office and residential buildings overlooking the Potomac River . Additionally, restaurants, bars, and shops have been opened at street level. Many of these buildings have

8658-479: The following subsystems: The bandwidth available from a satellite depends upon the number of transponders provided by the satellite. Each service (TV, Voice, Internet, radio) requires a different amount of bandwidth for transmission. This is typically known as link budgeting and a network simulator can be used to arrive at the exact value. Allocating frequencies to satellite services is a complicated process which requires international coordination and planning. This

8769-404: The freezing mark (32 °F or 0 °C). On average, the first day with a minimum at or below freezing is November 18 and the last day is March 27. Washington, D.C., was a planned city , and many of the city's street grids were developed in that initial plan. In 1791, President George Washington commissioned Pierre Charles L'Enfant , a French-born military engineer and artist, to design

8880-404: The ground, do not require as high signal strength (signal strength falls off as the square of the distance from the source, so the effect is considerable). Thus there is a trade off between the number of satellites and their cost. In addition, there are important differences in the onboard and ground equipment needed to support the two types of missions. A group of satellites working in concert

8991-436: The individual charters of the cities of Washington and Georgetown , abolished Washington County , and created a new territorial government for the whole District of Columbia. These steps made "the city of Washington...legally indistinguishable from the District of Columbia." In 1873, President Grant appointed Alexander Robey Shepherd as Governor of the District of Columbia. Shepherd authorized large projects that modernized

9102-437: The late 1990s. In 1973, Congress enacted the District of Columbia Home Rule Act providing for an elected mayor and 13-member council for the district. In 1975, Walter Washington became the district's first elected and first black mayor. Since the 1980s, the D.C. statehood movement has grown in prominence. In 2016, a referendum on D.C. statehood resulted in an 85% support among Washington, D.C., voters for it to become

9213-515: The late 20th century. Satellite communications are still used in many applications today. Remote islands such as Ascension Island , Saint Helena , Diego Garcia , and Easter Island , where no submarine cables are in service, need satellite telephones. There are also regions of some continents and countries where landline telecommunications are rare to non existent, for example large regions of South America, Africa, Canada, China, Russia, and Australia. Satellite communications also provide connection to

9324-566: The more than one hundred satellites in service worldwide. Other major satellite manufacturers include Space Systems/Loral , Orbital Sciences Corporation with the Star Bus series, Indian Space Research Organisation , Lockheed Martin (owns the former RCA Astro Electronics/GE Astro Space business), Northrop Grumman , Alcatel Space, now Thales Alenia Space , with the Spacebus series, and Astrium . Geostationary satellites must operate above

9435-497: The name Washington, Douglas Commonwealth (thus keeping the same abbreviation Washington, D.C.). The legalities, reasons, and impact of statehood have been heavily debated in the 2020s. Washington, D.C., is located in the Mid-Atlantic region of the U.S. East Coast . The city has a total area of 68.34 square miles (177 km ), of which 61.05 square miles (158.1 km ) is land and 7.29 square miles (18.9 km ) (10.67%)

9546-561: The nation's 51st state . In March 2017, the city's congressional delegate Eleanor Holmes Norton introduced a bill for statehood. Reintroduced in 2019 and 2021 as the Washington, D.C., Admission Act , the U.S. House of Representatives passed it in April 2021. After not progressing in the Senate, the statehood bill was introduced again in January 2023. The bill would have made D.C. into a state with one representative and two senators, with

9657-496: The new capital. He enlisted the help of Isaac Roberdeau, Étienne Sulpice Hallet and Scottish surveyor Alexander Ralston to help lay out the city plan. The L'Enfant Plan featured broad streets and avenues radiating out from rectangles, providing room for open space and landscaping. L'Enfant was also provided a roll of maps by Thomas Jefferson depicting Frankfurt, Amsterdam, Strasbourg, Paris, Orleans, Bordeaux, Lyon, Marseille, Turin, and Milan. L'Enfant's design also envisioned

9768-604: The new national capital in the Southern United States . On July 9, 1790, Congress passed the Residence Act , which approved the creation of a national capital on the Potomac River . Under the Residence Act, the exact location was to be selected by President George Washington , who signed the bill into law on July 16, 1790. Formed from land donated by Maryland and Virginia, the initial shape of

9879-552: The north and south sides of the National Mall, respectively, are home to many of Washington's iconic museums, including many Smithsonian Institution buildings and the National Archives Building . Washington hosts 177 foreign embassies ; these maintain nearly 300 buildings and more than 1,600 residential properties, many of which are on a section of Massachusetts Avenue informally known as Embassy Row . The architecture of Washington, D.C., varies greatly and

9990-470: The northern hemisphere. This orbit provides a long dwell time over Russian territory as well as over Canada at higher latitudes than geostationary orbits over the equator. Communications satellites usually have one of three primary types of orbit , while other orbital classifications are used to further specify orbital details. MEO and LEO are non-geostationary orbit (NGSO). As satellites in MEO and LEO orbit

10101-404: The number of blocks away from the Capitol. Most streets are set out in a grid pattern with east–west streets named with letters (e.g., C Street SW), north–south streets with numbers (e.g., 4th Street NW), and diagonal avenues, many of which are named after states . The City of Washington was bordered on the north by Boundary Street (renamed Florida Avenue in 1890); Rock Creek to the west, and

10212-564: The other hand, amplify the received signal before retransmitting it to the receiver on the ground. Passive satellites were the first communications satellites, but are little used now. Work that was begun in the field of electrical intelligence gathering at the United States Naval Research Laboratory in 1951 led to a project named Communication Moon Relay . Military planners had long shown considerable interest in secure and reliable communications lines as

10323-519: The payload. The bus can be customized, including compatibility with all commercially available launch vehicles and the option to launch with another spacecraft on certain launch vehicles. In addition to increased payload power, GEOStar-3 also has the option of utilizing electric propulsion, which allows it to complete its fifteen to seventeen year mission life with less fuel. Communications satellite The radio waves used for telecommunications links travel by line of sight and so are obstructed by

10434-419: The return of Alexandria. On July 9, 1846, Congress went further, agreeing to return all territory that Virginia had ceded to the district during its formation. This left the district's area consisting only of the portion originally donated by Maryland. Confirming the fears of pro-slavery Alexandrians, the Compromise of 1850 outlawed the slave trade in the district, although not slavery itself. The outbreak of

10545-432: The risk of signal interference. In October 1945, Arthur C. Clarke published an article titled "Extraterrestrial Relays" in the British magazine Wireless World . The article described the fundamentals behind the deployment of artificial satellites in geostationary orbits to relay radio signals. Because of this, Arthur C. Clarke is often quoted as being the inventor of the concept of the communications satellite, and

10656-1047: The same linear polarization as FSS-class satellites. Examples of these are the Astra , Eutelsat , and Hotbird spacecraft in orbit over the European continent. Because of this, the terms FSS and DBS are more so used throughout the North American continent, and are uncommon in Europe. Fixed Service Satellites use the C band , and the lower portions of the K u band . They are normally used for broadcast feeds to and from television networks and local affiliate stations (such as program feeds for network and syndicated programming, live shots , and backhauls ), as well as being used for distance learning by schools and universities, business television (BTV), Videoconferencing , and general commercial telecommunications. FSS satellites are also used to distribute national cable channels to cable television headends. Free-to-air satellite TV channels are also usually distributed on FSS satellites in

10767-408: The signal coming from the source, toward the direction of the receiver. With passive satellites, the reflected signal is not amplified at the satellite, and only a small amount of the transmitted energy actually reaches the receiver. Since the satellite is so far above Earth, the radio signal is attenuated due to free-space path loss , so the signal received on Earth is very weak. Active satellites, on

10878-402: The sky for transmission of communication signals. However, due to their closer distance to the Earth, LEO or MEO satellites can communicate to ground with reduced latency and at lower power than would be required from a geosynchronous orbit. A low Earth orbit (LEO) typically is a circular orbit about 160 to 2,000 kilometres (99 to 1,243 mi) above the Earth's surface and, correspondingly,

10989-590: The term 'Clarke Belt' is employed as a description of the orbit. The first artificial Earth satellite was Sputnik 1 , which was put into orbit by the Soviet Union on 4 October 1957. It was developed by Mikhail Tikhonravov and Sergey Korolev , building on work by Konstantin Tsiolkovsky . Sputnik 1 was equipped with an on-board radio transmitter that worked on two frequencies of 20.005 and 40.002 MHz, or 7 and 15 meters wavelength. The satellite

11100-541: The width of the adjacent street plus 20 feet (6.1 m). Despite popular belief, no law has ever limited buildings to the height of the United States Capitol or the 555-foot (169 m) Washington Monument , which remains the district's tallest structure. City leaders have cited the height restriction as a primary reason that the district has limited affordable housing and its metro area has suburban sprawl and traffic problems. Washington, D.C., still has

11211-515: Was Project SCORE , led by Advanced Research Projects Agency (ARPA) and launched on 18 December 1958, which used a tape recorder to carry a stored voice message, as well as to receive, store, and retransmit messages. It was used to send a Christmas greeting to the world from U.S. President Dwight D. Eisenhower . The satellite also executed several realtime transmissions before the non-rechargeable batteries failed on 30 December 1958 after eight hours of actual operation. The direct successor to SCORE

11322-419: Was a poetic name for the United States commonly used at that time. Congress held its first session there on November 17, 1800. Congress passed the District of Columbia Organic Act of 1801 , which officially organized the district and placed the entire territory under the exclusive control of the federal government. The area within the district was organized into two counties, the County of Washington to

11433-429: Was another ARPA-led project called Courier. Courier 1B was launched on 4 October 1960 to explore whether it would be possible to establish a global military communications network by using "delayed repeater" satellites, which receive and store information until commanded to rebroadcast them. After 17 days, a command system failure ended communications from the satellite. NASA 's satellite applications program launched

11544-583: Was forced by the Pennsylvania Mutiny of 1783 to move to Princeton, Congress resolved to consider a new location for it. The following day, Elbridge Gerry of Massachusetts moved "that buildings for the use of Congress be erected on the banks of the Delaware near Trenton , or of the Potomac , near Georgetown , provided a suitable district can be procured on one of the rivers as aforesaid, for

11655-428: Was in intercontinental long distance telephony . The fixed Public Switched Telephone Network relays telephone calls from land line telephones to an Earth station , where they are then transmitted to a geostationary satellite. The downlink follows an analogous path. Improvements in submarine communications cables through the use of fiber-optics caused some decline in the use of satellites for fixed telephony in

11766-492: Was launched, the United States was the only launch source outside of the Soviet Union , who did not participate in the Intelsat agreements. The Soviet Union launched its first communications satellite on 23 April 1965 as part of the Molniya program. This program was also unique at the time for its use of what then became known as the Molniya orbit , which describes a highly elliptical orbit , with two high apogees daily over

11877-439: Was named after George Washington , the first president of the United States . The district is named after Columbia , the female personification of the nation . The U.S. Constitution in 1789 called for the creation of a federal district under the exclusive jurisdiction of the U.S. Congress . As such, Washington, D.C., is not part of any state , and is not one itself. The Residence Act , adopted on July 16, 1790, approved

11988-493: Was needed to track it. Its successor, Syncom 3 , launched on 19 July 1964, was the first geostationary communications satellite. Syncom 3 obtained a geosynchronous orbit, without a north–south motion, making it appear from the ground as a stationary object in the sky. A direct extension of the passive experiments of Project West Ford was the Lincoln Experimental Satellite program, also conducted by

12099-500: Was not placed in orbit to send data from one point on Earth to another, but the radio transmitter was meant to study the properties of radio wave distribution throughout the ionosphere. The launch of Sputnik 1 was a major step in the exploration of space and rocket development, and marks the beginning of the Space Age . There are two major classes of communications satellites, passive and active . Passive satellites only reflect

12210-644: Was subject to instruction by the US Government on matters of national policy. Over the next two years, international negotiations led to the Intelsat Agreements, which in turn led to the launch of Intelsat 1, also known as Early Bird, on 6 April 1965, and which was the first commercial communications satellite to be placed in geosynchronous orbit. Subsequent Intelsat launches in the 1960s provided multi-destination service and video, audio, and data service to ships at sea (Intelsat 2 in 1966–67), and

12321-591: Was the first active, direct relay communications commercial satellite and marked the first transatlantic transmission of television signals. Belonging to AT&T as part of a multi-national agreement between AT&T, Bell Telephone Laboratories , NASA, the British General Post Office , and the French National PTT (Post Office) to develop satellite communications, it was launched by NASA from Cape Canaveral on 10 July 1962, in

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