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Boeing 601
The Boeing 601 (sometimes referred to as the BSS-601, and previously as the HS-601) is a communications satellite bus designed in 1985 and introduced in 1987 by Hughes Space and Communications Company. The series was extremely popular in the 1990s, with more than 84 purchased by customers globally. The more advanced 601HP derivative (for "high power") was introduced in 1995. Hughes, and the 601 platforms, were acquired by Boeing in 2000. The last commercial 601 satellite was ordered in 2001 and launched in 2004. The NASA Space Communications and Navigation (SCaN) Program Office in December 2007 selected the BSS-601HP for its third generation TDRS spacecraft, adding the two 15-foot (4.5m) diameter steerable antennas. The TDRS-M satellite, launched on August 18, 2017, became the last 601 satellite to reach orbit. Background The Boeing-601 model was Hughes’ first major design and development for a communications satellite with three-axis, or body stabilization. All previous Hug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TDRS-M
TDRS-13, known before launch as TDRS-M, is an American communications satellite operated by NASA as part of the Tracking and Data Relay Satellite System. The thirteenth Tracking and Data Relay Satellite, it is the third and final third-generation spacecraft to be launched, following the 2014 launch of TDRS-12. Spacecraft TDRS-M was constructed by Boeing, based on the BSS-601HP satellite bus. Fully fueled, it has a mass of , with a design life of 15 years. It carries two steerable antennas capable of providing S, Ku and Ka band communications for other spacecraft, with an additional array of S-band transponders for lower-rate communications with five further satellites. The satellite is powered by two solar arrays, which produce 2.8 to 3.2 kilowatts of power, while an R-4D-11-300 engine is present to provide propulsion. Launch In 2015, NASA contracted with United Launch Alliance to launch TDRS-M on an Atlas V 401 for $132.4 million. The spacecraft was launched on 18 Augus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Array
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and convert sunlight into electricity, a solar inverter to convert the output from direct to alternating current, as well as mounting, cabling, and other electrical accessories to set up a working system. It may also use a solar tracking system to improve the system's overall performance and include an integrated battery. PV systems convert light directly into electricity, and are not to be confused with other solar technologies, such as concentrated solar power or solar thermal, used for heating and cooling. A solar array only encompasses the ensemble of solar panels, the visible part of the PV system, and does not include all the other hardware, often summarized as balance of system (BOS). PV systems range from small, rooftop-mounted or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DIRECTV 1
DirecTV (trademarked as DIRECTV) is an American multichannel video programming distributor based in El Segundo, California. Originally launched on June 17, 1994, its primary service is a digital satellite service serving the United States. It also provides traditional linear television service delivered by IP through its U-verse TV brand and a Virtual MVPD service through its DirecTV Stream brand. Its primary competitors are Dish Network, traditional cable television providers, IP-based television services, and other over-the-top video services. On July 24, 2015, after receiving approval from the Federal Communications Commission and the Department of Justice, AT&T acquired DirecTV in a transaction valued at $67.1 billion. As of the end of Q1 2021, AT&T had 15.9 million pay-TV customers, including DirecTV, U-Verse, and DirecTV Stream subscribers. On February 25, 2021, AT&T announced that it would spin-off DirecTV, U-Verse TV, and DirecTV Stream into a separate en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DirecTV
DirecTV (trademarked as DIRECTV) is an American multichannel video programming distributor based in El Segundo, California. Originally launched on June 17, 1994, its primary service is a digital satellite service serving the United States. It also provides traditional linear television service delivered by IP through its U-verse TV brand and a Virtual MVPD service through its DirecTV Stream brand. Its primary competitors are Dish Network, traditional cable television providers, IP-based television services, and other over-the-top video services. On July 24, 2015, after receiving approval from the Federal Communications Commission and the Department of Justice, AT&T acquired DirecTV in a transaction valued at $67.1 billion. As of the end of Q1 2021, AT&T had 15.9 million pay-TV customers, including DirecTV, U-Verse, and DirecTV Stream subscribers. On February 25, 2021, AT&T announced that it would spin-off DirecTV, U-Verse TV, and DirecTV Stream into a separate e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AsiaSat 4
AsiaSat 4 was a Hong Kong communications satellite, which was owned, and was initially operated, by the Hong Kong based AsiaSat, Asia Satellite Telecommunications Company (AsiaSat). It was positioned in geostationary orbit at a longitude of 122° East of the Prime meridian (Greenwich), Greenwich Meridian. It spent most of its operational life at 122° East, from where it was used to provide fixed satellite services, including broadcasting, audio and data transmission, to Asia and the Pacific Ocean. Satellite description AsiaSat 4 was built by Hughes Space and Communications, for US$220 million, which by the time of its launch had become part of Boeing Satellite Development Center, Boeing Satellite Systems. It is based on the Boeing 601 , HS-601HP satellite bus. At launch, it had a mass of , and a design life of fifteen years. It carries twenty eight C band (IEEE), C-band and twenty Ku band, Ku-band Transponder (satellite communications), transponders. It was planned for late 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AsiaSat 3S
AsiaSat 3S, was a geosynchronous communications satellite for AsiaSat of Hong Kong to provide communications and television services all across Asia, the Middle East and Oceania Oceania (, , ) is a region, geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern Hemisphere, Eastern and Western Hemisphere, Western hemispheres, Oceania is estimated to have a land area of .... Background In March 1998, AsiaSat ordered a replacement satellite, for US$195 million, from Hughes Space and Communications. Designated AsiaSat 3S, the new satellite is a replica of PAS-22, AsiaSat 3. Launch AsiaSat 3S was launched for AsiaSat by a Proton-K / Blok D, DM-2M launch vehicle on 21 March 1999, at 00:09:30 Coordinated Universal Time, UTC, destined for an orbital location at 105.5° East. A replacement for Asiasat 3, placed in the wrong orbit by a Proton launch in 1997, Asiasat 3S carried C band (IEEE), C-band and Ku band, Ku-band Transpon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AsiaSat
Asia Satellite Telecommunications Holdings Limited, known by its brand name AsiaSat, is a commercial operator of communication spacecraft. AsiaSat, based in Hong Kong, is incorporated in Bermuda. AsiaSat is jointly owned by Chinese state-owned CITIC Limited and private equity fund The Carlyle Group L.P. indirectly. It had a market capitalization of HK$2 billion on 30 November 2018. It was a red chip company of the stock exchange. On 23 August 2019, the take private proposal scheme was approved by AsiaSat's public shareholders, followed by the approval of the Bermuda Court on 3 September 2019, whereupon the Company became a private wholly owned subsidiary of Bowenvale Limited, a joint venture of CITIC and Carlyle. The listing of the company's shares was withdrawn from the Stock Exchange of Hong Kong on 5 September 2019. History In September 2017, AsiaSat 9, AsiaSat's latest satellite built by Space Systems/Loral was successfully launched and replaced AsiaSat 4 at 122° East. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apstar 2
Apstar 2 was a communications satellite based on the Hughes HS-601 spacecraft design, built by Hughes Space and Communications Company for APT Satellite Holdings, a Hong-Kong based company. The satellite was intended to provide video, radio, data, and telephone services to about 2/3 of the world's population. It was launched on Jan. 26, 1995 by a Long March 2E launcher from Xichang Satellite Launch Center in China, but was destroyed 50 seconds after liftoff when the rocket exploded. The failed rocket also veered off course after launch and killed at least six people on the ground. The Hughes Failure Investigation Team found that excess vibration had caused a rocket fairing to fail due to a structural deficiency. However, the Chinese blamed the rocket-satellite interface for the failure. The two sides agreed that the fairing and the satellite interface would both be improved. The Long March 2E rocket would be retired at the end of 1995. Political effects The Apstar 2 failure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
APT Satellite Holdings
APT Satellite Holdings Limited is a Bermuda-incorporated holding company. Its Hong Kong-incorporated subsidiary APT Satellite Co., Ltd. is the operator of the Apstar satellite constellation. APT Satellite Holdings and APT Satellite are headquartered in Hong Kong. As at 30 June 2016 the company had a market capitalisation of HK$3.816 billion. It is a red chip company, as it was an overseas incorporated company, but controlled by the Chinese Government indirectly (via China Aerospace Science and Technology Corporation). Fellow Hong Kong-based satellite company AsiaSat was also partially owned by the Chinese Government (via CITIC Group), but belongs to a different department of the State Council. History The establishment of APT Satellite Company Limited was officially approved by the State Council of the People's Republic of China on 26 March 1992, the company's incorporation on 21 January 1992 as Free Union Limited, renaming to Trans-Asia-Pacific Satellite Communications Co., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XIPS
The gridded ion thruster is a common design for ion thrusters, a highly efficient low-thrust spacecraft propulsion method running on electrical power by using high-voltage grid electrodes to accelerate ions with electrostatic forces. History The ion engine was first demonstrated by German-born NASA scientist Ernst Stuhlinger, and developed in practical form by Harold R. Kaufman at NASA Lewis (now Glenn) Research Center from 1957 to the early 1960s. The use of ion propulsion systems were first demonstrated in space by the NASA Lewis " Space Electric Rocket Test" (SERT) I and II.J. S. Sovey, V. K. Rawlin, and M. J. Patterson, "Ion Propulsion Development Projects in U. S.: Space Electric Rocket Test 1 to Deep Space 1", ''Journal of Propulsion and Power, Vol. 17'', No. 3, May–June 2001, pp. 517-526. These thrusters used mercury as the reaction mass. The first was SERT-1, launched July 20, 1964, which successfully proved that the technology operated as predicted in space. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy IV
Galaxy IV was a model HS-601 satellite built by Hughes Space and Communications Company (HSC). The satellite, which carried a payload of both C band and Ku band transponders, was launched on June 24, 1993 and operated by PanAmSat Corporation. It was in geostationary orbit at 99°W. Failure Control of Galaxy IV was lost on May 19, 1998 when the satellite's primary control processor failed. The backup control processor had suffered a previously undetected anomaly, and PanAmSat was not able to regain control of the spacecraft. Galaxy IV was declared a loss on May 20, 1998. Failure of the primary control processor was attributed to tin whisker growth, a phenomenon in which tendrils grow from solder, causing an electrical short circuit. Engineers believe that a hole developed in the conformal wax coating over the solder, allowing whiskers to develop. The satellite manufacturer, Hughes, has replaced pure tin plating with nickel to alleviate the problem in newer designs, adding per p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whisker (metallurgy)
Metal whiskering is a phenomenon which occurs in electrical devices when metals form long whisker-like projections over time. Tin whiskers were noticed and documented in the vacuum tube era of electronics early in the 20th century in equipment that used pure, or almost pure, tin solder in their production. It was noticed that small metal hairs or tendrils grew between metal solder pads, causing short circuits. Metal whiskers form in the presence of compressive stress. Germanium, zinc, cadmium, and even lead whiskers have been documented. Many techniques are used to mitigate the problem, including changes to the annealing process (heating and cooling), the addition of elements like copper and nickel, and the inclusion of conformal coatings. Traditionally, lead has been added to slow down whisker growth in tin-based solders. Following the Restriction of Hazardous Substances Directive (RoHS), the European Union banned the use of lead in most consumer electronic products from 2006 d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
