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TDRS-1
TDRS-1, known before launch as TDRS-A, was an American communications satellite, operated by NASA as part of the Tracking and Data Relay Satellite System. It was constructed by TRW and launched by on its maiden flight, STS-6. History While on the pad, problems were detected with ''Challenger'' main engines and repairs were begun. During this time, a severe storm caused contamination of TDRS-1 while it was in the Payload Change-out Room on the Rotating Service Structure at the launch pad. Consequently, the satellite had to be taken back to its checkout facility, where it was cleaned and rechecked. ''Challenger'' finally lifted off from Launch Complex 39A of the Kennedy Space Center at 18:30:00 UTC on 4 April 1983. Operations Following deployment from ''Challenger'', TDRS-1 was to be raised to its operational geosynchronous orbit by means of an Inertial Upper Stage, which consisted of two solid rocket motors, the first used to raise the orbit's apogee, the second its perigee. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently. The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth. The purpose of communications sate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apsis
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g., f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lincoln Experimental Satellite
The Lincoln Experimental Satellite series was designed and built by Lincoln Laboratory at Massachusetts Institute of Technology between 1965 and 1976, under USAF sponsorship, for testing devices and techniques for satellite communication. Development After the successful development and deployment of Project West Ford, a passive communications system consisting of orbiting copper needles, MIT's Lincoln Laboratory turned to improving active-satellite space communications. In particular, Lincoln aimed to increase the transmission capability of communications satellites ("downlink"), which was necessarily constrained by their limited size. After receiving a charter in 1963 to build and demonstrate military space communications, Lincoln focused on a number of engineering solutions to the downlink problem including improved antennas, better stabilization of satellites in orbit (which would benefit both downlink and "uplink"—communications from the ground), high-efficiency systems of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GOES 3
GOES-3, known as GOES-C before becoming operational, was an American geostationary weather and communications satellite. It was originally built for the National Oceanic and Atmospheric Administration as part of the Geostationary Operational Environmental Satellite system, and was launched in June 1978. It was positioned in geostationary orbit, from where it was initially used for weather forecasting in the United States. Since ceasing to function as a weather satellite in 1989, it was used as a communications satellite, and spent over thirty-eight years in operation. GOES-3 was decommissioned 29 June 2016 at the Center for Southeastern Tropical Advanced Remote Sensing facility in Miami, Florida. GOES-3 was built by Ford Aerospace, and was based on the satellite bus developed for the SMS programme. At launch it had a mass of . Launch GOES-C was launched using a Delta 2914 carrier rocket flying from Launch Complex 17B at the Cape Canaveral Air Force Station. The launch occurre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marisat 2
Marisat 2 (or Marisat F2) is a communications satellite operated by COMSAT. Marisat 2 was the second of a series of COMSAT maritime communications satellites. Satellite The spacecraft was capable of transmitting voice, data, facsimile and telex messages to and from ships at sea through special shore stations at Southbury, Connecticut and Saint Paul, CA, which were interconnected with existing domestic terrestrial networks. The system was initially utilized primarily by the U.S. Navy, with a limited amount of satellite capacity provided in different frequency bands (L band), through separate satellite transponders, for maritime communications services to commercial entities and other interested users. At such time as the Navy's requirements terminate (late 1970s) substantial satellite capacity will become available for commercial maritime purposes. Following launch, satellite operation was nominal. It was placed in geosynchronous orbit at 176.5 degrees west and using propulsion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Pole
The South Pole, also known as the Geographic South Pole, Terrestrial South Pole or 90th Parallel South, is one of the two points where Earth's axis of rotation intersects its surface. It is the southernmost point on Earth and lies antipodally on the opposite side of Earth from the North Pole, at a distance of 12,430 miles (20,004 km) in all directions. Situated on the continent of Antarctica, it is the site of the United States Amundsen–Scott South Pole Station, which was established in 1956 and has been permanently staffed since that year. The Geographic South Pole is distinct from the South Magnetic Pole, the position of which is defined based on Earth's magnetic field. The South Pole is at the centre of the Southern Hemisphere. Geography For most purposes, the Geographic South Pole is defined as the southern point of the two points where Earth's axis of rotation intersects its surface (the other being the Geographic North Pole). However, Earth's axis of rotat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Pole
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface. It is called the True North Pole to distinguish from the Magnetic North Pole. The North Pole is by definition the northernmost point on the Earth, lying antipodally to the South Pole. It defines geodetic latitude 90° North, as well as the direction of true north. At the North Pole all directions point south; all lines of longitude converge there, so its longitude can be defined as any degree value. No time zone has been assigned to the North Pole, so any time can be used as the local time. Along tight latitude circles, counterclockwise is east and clockwise is west. The North Pole is at the center of the Northern Hemisphere. The nearest land is usually said to be Kaffeklubben Island, off the northern coast of Greenland about away, though some perhaps semi-permanent gravel banks lie slightly clos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planet's equator. For pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium Communications
Iridium Communications Inc. (formerly Iridium Satellite LLC) is a publicly traded American company headquartered in McLean, Virginia. Iridium operates the Iridium satellite constellation, a system of 66 active satellites and 9 in-orbit spares used for worldwide voice and data communication from hand-held satellite phones and other transceiver units. The nearly polar orbit and communication between satellites via inter-satellite links provide global service availability. History The Iridium communications service was launched on November 1, 1998, formerly known as Iridium SSC. The first Iridium call was made by Vice President of the United States Al Gore to Gilbert Grosvenor, the great-grandson of Alexander Graham Bell and chairman of the National Geographic Society. Motorola provided the technology and major financial backing. The logo of the company represents the Big Dipper. The company derives its name from the chemical element iridium, which has an atomic number of 77, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
March 1989 Geomagnetic Storm
The March 1989 geomagnetic storm occurred as part of severe to extreme solar storms during early to mid March 1989, the most notable being a geomagnetic storm that struck Earth on March 13. This geomagnetic storm caused a nine-hour outage of Hydro-Québec's electricity transmission system. The onset time was exceptionally rapid. Other historically significant solar storms occurred later in 1989, during a very active period of solar cycle 22. Geomagnetic storm and auroras The geomagnetic storm causing this event is believed to be the result of two separate events known as coronal mass ejections (CME) on March 10 and 12, 1989. A few days before, on March 6, a very large X15-class solar flare also occurred. Several days later, at 01:27 UT on March 13, a severe geomagnetic storm struck Earth. The storm began on Earth with extremely intense auroras at the poles. The aurora could be seen as far south as Texas and Florida. As this occurred during the Cold War, an unknown number of people ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert H
The name Robert is an ancient Germanic given name, from Proto-Germanic "fame" and "bright" (''Hrōþiberhtaz''). Compare Old Dutch ''Robrecht'' and Old High German ''Hrodebert'' (a compound of '' Hruod'' ( non, Hróðr) "fame, glory, honour, praise, renown" and ''berht'' "bright, light, shining"). It is the second most frequently used given name of ancient Germanic origin. It is also in use as a surname. Another commonly used form of the name is Rupert. After becoming widely used in Continental Europe it entered England in its Old French form ''Robert'', where an Old English cognate form (''Hrēodbēorht'', ''Hrodberht'', ''Hrēodbēorð'', ''Hrœdbœrð'', ''Hrœdberð'', ''Hrōðberχtŕ'') had existed before the Norman Conquest. The feminine version is Roberta. The Italian, Portuguese, and Spanish form is Roberto. Robert is also a common name in many Germanic languages, including English, German, Dutch, Norwegian, Swedish, Scots, Danish, and Icelandic. It can be use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maryland
Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to its east. Baltimore is the largest city in the state, and the capital is Annapolis. Among its occasional nicknames are '' Old Line State'', the ''Free State'', and the '' Chesapeake Bay State''. It is named after Henrietta Maria, the French-born queen of England, Scotland, and Ireland, who was known then in England as Mary. Before its coastline was explored by Europeans in the 16th century, Maryland was inhabited by several groups of Native Americans – mostly by Algonquian peoples and, to a lesser degree, Iroquoian and Siouan. As one of the original Thirteen Colonies of England, Maryland was founded by George Calvert, 1st Baron Baltimore, a Catholic convert"George Calvert and Cecilius Calvert, Barons Baltimore" William Hand Browne, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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