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Teledesic
Teledesic was a company founded in the 1990s to build a commercial broadband satellite internet constellation. Using low-Earth-orbiting satellites small antennas could be used to provide uplinks of as much as 100 Mbit/s and downlinks of up to 720 Mbit/s. The original 1994 proposal was extremely ambitious, costing over 9 billion USD and originally planning 840 active satellites with in-orbit spares at an altitude of 700 km. In 1997, the plan was scaled back to 288 active satellites at 1400 km. Teledesic Corporation changed its name to Teledesic, LLC by pro forma assignment of its license, granted on 26 January 1998. The commercial failure of the similar Iridium and Globalstar ventures (composed of 66 and 48 operational satellites respectively) and other systems, along with bankruptcy protection filings, were primary factors in halting the project, and Teledesic officially suspended its satellite construction work on 1 October 2002. Description The Teledesic system would have provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teledesic Satellite
Teledesic was a company founded in the 1990s to build a commercial broadband satellite internet constellation. Using low-Earth-orbiting satellites small antennas could be used to provide uplinks of as much as 100 Mbit/s and downlinks of up to 720 Mbit/s. The original 1994 proposal was extremely ambitious, costing over 9 billion USD and originally planning 840 active satellites with in-orbit spares at an altitude of 700 km. In 1997, the plan was scaled back to 288 active satellites at 1400 km. Teledesic Corporation changed its name to Teledesic, LLC by pro forma assignment of its license, granted on 26 January 1998. The commercial failure of the similar Iridium and Globalstar ventures (composed of 66 and 48 operational satellites respectively) and other systems, along with bankruptcy protection filings, were primary factors in halting the project, and Teledesic officially suspended its satellite construction work on 1 October 2002. Description The Teledesic system would have provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craig McCaw
Craig McCaw (born August 11, 1949) is an American businessman and entrepreneur, a pioneer in the cellular phone industry. He is the founder of McCaw Cellular (now part of AT&T Mobility) and Clearwire Corporation (now part of T-Mobile via the Sprint acquisition). Early life and cable TV beginnings McCaw is the second of four sons of Marion and J. Elroy McCaw. He attended the Lakeside School, where he was later given a Lakeside Distinguished Alumni Award. McCaw's father was a broadcasting magnate and owner of Gotham Broadcasting Corporation. Gotham owned the New York City radio station WINS, which became one of the first stations to play rock and roll, with Alan Freed being one of the earliest famous disc jockeys on the station. McCaw's father was in the business of buying and selling TV and radio stations, which brought in wealth but also incurred significant debts. Elroy entered the cable television business in the 1960s, and his four sons worked as linemen and door-to-door sal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Internet Constellation
A satellite internet constellation is a constellation of artificial satellites providing satellite internet service. In particular, the term has come to refer to a new generation of very large constellations (sometimes referred to as a megaconstellations ) orbiting in low Earth orbit (LEO) to provide low-latency, high bandwidth (broadband) internet service. History While more-limited satellite internet services have been available through geosynchronous commsats orbiting in geostationary orbit for years, these have been of quite limited bandwidth (not broadband), high- latency, and provided at such a relatively high price that demand for the services offered has been quite low. In the 1990s, several LEO satellite internet constellations were proposed and developed, including Celestri (63 satellites) and Teledesic (initially 840, later 288 satellites). These projects were abandoned after the bankruptcy of the Iridium and Globalstar satellite phone constellations in the ea ... [...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] |
Globalstar
Globalstar, Inc. is an American satellite communications company that operates a low Earth orbit (LEO) satellite constellation for satellite phone and low-speed data communications. The Globalstar second-generation constellation consists of 24 low Earth orbiting (LEO) satellites. History The Globalstar project was launched in 1991 as a joint venture of Loral Corporation and Qualcomm. On March 24, 1994, the two sponsors announced the formation of Globalstar LP, a limited partnership established in the U.S., with financial participation from eight other companies, including Alcatel, AirTouch, Deutsche Aerospace, Hyundai, and Vodafone. At that time, the company predicted the system would launch in 1998, based on an investment of $1.8 billion. Globalstar received its US spectrum allocation from the FCC in January 1995 and continued to negotiate with other nations for rights to use the same radio frequencies in their countries. The first satellites were launched in February 1998, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alwaleed Bin Talal
Al Waleed bin Talal Al Saud ( ar, الوليد بن طلال آل سعود; born 7 March 1955) is a Saudi Arabian billionaire businessman, investor, philanthropist and royal. He was listed on ''Time'' magazine's Time 100, an annual list of the hundred most influential people in the world, in 2008. Al Waleed is a grandson of Abdulaziz, the first king of Saudi Arabia, and of Riad Al Solh, Lebanon's first prime minister. Al Waleed is the founder, chief executive officer and 95 percent owner of the Kingdom Holding Company, a company with investments in companies in the financial services, tourism and hospitality, mass media, entertainment, retail, agriculture, petrochemicals, aviation, technology, and real-estate sectors. In 2013, the company had a market capitalization of over $18 billion. He is a minor shareholder in Zaveriwala Holdings LLC, and owns Paris' Four Seasons Hotel George V and part of New York's Plaza Hotel. ''Time'' has called him the "Arabian Warren Buffett". In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McCaw Cellular Communications
McCaw Cellular Communications was a cellular telephone pioneer in the United States. Savvy licensing of cellular spectrum in the early 1980s put McCaw Cellular in an extremely strong position, quickly outpacing the growth of the "Baby Bells" in the emerging market. The company purchased MCI Communications's mobile businesses in 1986, followed by LIN Broadcasting in 1989, giving them widespread access in all of the major US markets. Partnering with AT&T as a technology provider, McCaw introduced their "Cellular One" service in 1990, the first truly national cellular system. AT&T purchased 33% of the company in 1992, and arranged a merger in 1994 that made Craig McCaw one of AT&T's largest shareholders. In 2002, the company was spun off from AT&T to become AT&T Wireless Services. History McCaw Cellular Communications In 1966 J. Elroy McCaw sold one of his cable television holdings in Centralia, Washington to his three sons, including Craig who was 16 years old at the time. Craig t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northrop Grumman Pegasus
Pegasus is an air-launched launch vehicle developed by Orbital Sciences Corporation (OSC) and now built and launched by Northrop Grumman. Capable of carrying small payloads of up to into low Earth orbit, Pegasus first flew in 1990 and remains active . The vehicle consists of three solid propellant stages and an optional monopropellant fourth stage. Pegasus is released from its carrier aircraft at approximately , and its first stage has a wing and a tail to provide lift and attitude control while in the atmosphere. Notably, the first stage does not have a thrust vector control (TVC) system. History Pegasus was designed by a team led by Antonio Elias. The Pegasus's three Orion solid motors were developed by Hercules Aerospace (later Alliant Techsystems) specifically for the Pegasus launcher but using advanced carbon fiber, propellant formulation and case insulation technologies originally developed for the terminated USAF Small ICBM program. The wing and fins' structures w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E-carrier
The E-carrier is a member of the series of carrier systems developed for digital transmission of many simultaneous telephone calls by time-division multiplexing. The European Conference of Postal and Telecommunications Administrations (CEPT) originally standardized the E-carrier system, which revised and improved the earlier American T-carrier technology, and this has now been adopted by the International Telecommunication Union Telecommunication Standardization Sector (ITU-T). It was widely used in almost all countries outside the US, Canada, and Japan. E-carrier deployments have steadily been replaced by Ethernet as telecommunication networks transition towards all IP. E1 frame structure An E1 link operates over two separate sets of wires, usually unshielded twisted pair (balanced cable) or using coaxial (unbalanced cable). A nominal 3 volt peak signal is encoded with pulses using a method avoiding long periods without polarity changes. The line data rate is 2.048 Mbit/s ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Data Center
The World Data Centre (WDC) system was created to archive and distribute data collected from the observational programmes of the 1957–1958 International Geophysical Year by the International Council of Science ( ICSU). The WDCs were funded and maintained by their host countries on behalf of the international science community. Originally established in the United States, Europe, Soviet Union, and Japan, the WDC system expanded to other countries and to new scientific disciplines. The WDC system included up to 52 Centres in 12 countries. All data held in WDCs were available for the cost of copying and sending the requested information. At the end of 2008, following the ICSU General Assembly in Maputo (Mozambique), the World Data Centres were reformed and a new ICSU World Data System In its most general sense, the term "world" refers to the totality of entities, to the whole of reality or to everything that is. The nature of the world has been conceptualized differently i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Space Science Data Center
The NASA Space Science Data Coordinated Archive (NSSDCA) serves as the permanent archive for NASA space science mission data. "Space science" includes astronomy and astrophysics, solar and space plasma (physics), plasma physics, and planetary science, planetary and lunar science. As the permanent archive, NSSDCA teams with NASA's discipline-specific space science "active archives" which provide access to data to researchers and, in some cases, to the general public. NSSDCA also serves as NASA's permanent archive for space physics mission data. It provides access to several geophysical models and to data from some non-NASA mission data. NSSDCA was called the National Space Science Data Center (NSSDC) prior to March 2015. NSSDCA supports active space physics and astrophysics researchers. Web-based services allow the NSSDCA to support the general public. This support is in the form of information about spacecraft and access to digital versions of selected imagery. NSSDCA also provides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
