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Long March 2E
The Long March 2E, also known as the Chang Zheng 2E, CZ-2E and LM-2E, was a Chinese orbital carrier rocket from the Long March 2 family. The Long March 2E was a three-stage carrier rocket that was designed to launch commercial communications satellites into geosynchronous transfer orbit. Launches took place from launch complex 2 at the Xichang Satellite Launch Center. The Long March 2E made its maiden flight on 16 July 1990. However, the rocket had compatibility flaws with the American-made satellites that caused one launch failures and one partial failure in just 7 missions. The rocket was retired on 28 December 1995 in favor of the Long March 3B. The Long March 2E forms the basis of the Long March 2F, used to launch crewed Shenzhou missions. The booster rockets have also been used on the Long March 3B and Long March 3C. Launches The Long March 2E made its maiden flight on 16 July 1990 and made 7 launches in total. All of the failures were caused by excessive vibration. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Launch Vehicle
A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multistage rocket, but the term is more general and also encompasses vehicles like the Space Shuttle. Most launch vehicles operate from a launch pad, supported by a missile launch control center, launch control center and systems such as vehicle assembly and fueling. Launch vehicles are engineered with advanced aerodynamics and technologies, which contribute to high operating costs. An orbital spaceflight, orbital launch vehicle must lift its payload at least to the boundary of space, approximately and accelerate it to a horizontal velocity of at least . Suborbital spaceflight, Suborbital vehicles launch their payloads to lower velocity or are launched at elevation angles greater than horizontal. Practical orbital launch vehicles use chemical prope ... [...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 (satellite communications), transponder; it creates a communication channel between a source transmitter and a Radio receiver, 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 radio waves used for telecommunications links travel by Line-of-sight propagation, line of sight and so are obstructe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bureau Of Industry And Security
The Bureau of Industry and Security (BIS) is an agency of the United States Department of Commerce that deals with issues involving national security and high technology. A principal goal for the bureau is helping stop the proliferation of weapons of mass destruction, while furthering the growth of United States exports. The Bureau is led by the Under Secretary of Commerce for Industry and Security. BIS' mission is to advance U.S. national security, foreign policy, and economic interests. BIS activities include regulating the export of sensitive goods and dual-use technologies in an effective and efficient manner; enforcing export control, anti-boycott, and public safety laws; cooperating with and assisting other countries on export control and strategic trade issues; assisting U.S. industry to comply with international arms control agreements; monitoring the viability of the U.S. defense–industrial base; and promoting federal initiatives and public-private partnerships ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Traffic In Arms Regulations
International Traffic in Arms Regulations (ITAR) is a set of U.S. Department of State regulations that control the export of defense and military technologies to safeguard national security and further its foreign policy objectives. Overview The United States government has adopted two types of regulations to control exports of military-relevant items: ITAR, which cover weapons and defense articles specifically (such as missiles); and the Export Administration Regulations, which cover items that may have uses in defense articles (such as a radar component used in a certain missile). Defense-related articles and services on the United States Munitions List (USML) are covered by the ITAR, which implement the provisions of the Arms Export Control Act (AECA), and are described in Title 22 (Foreign Relations), Chapter I (Department of State), Subchapter M of the Code of Federal Regulations. The Department of State Directorate of Defense Trade Controls (DDTC) interprets and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Department Of State
The United States Department of State (DOS), or simply the State Department, is an United States federal executive departments, executive department of the U.S. federal government responsible for the country's foreign policy of the United States, foreign policy and foreign relations of the United States, relations. Equivalent to the ministry of foreign affairs of other nations, its primary duties are advising the U.S. president on international relations, administering List of diplomatic missions of the United States, diplomatic missions, negotiating international treaties and agreements, protecting citizens abroad and representing the U.S. at the United Nations. The department is headquartered in the Harry S Truman Building, a few blocks from the White House, in the Foggy Bottom, Washington, D.C., Foggy Bottom neighborhood of Washington, D.C.; "Foggy Bottom" is thus sometimes used as a metonym. Established in 1789 as the first administrative arm of the U.S. executive branch, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammunition
Ammunition, also known as ammo, is the material fired, scattered, dropped, or detonated from any weapon or weapon system. The term includes both expendable weapons (e.g., bombs, missiles, grenades, land mines), and the component parts of other weapons that create the effect on a target (e.g., bullets and warheads). The purpose of ammunition is to project a force against a selected Targeting (warfare), target to have an effect (usually, but not always, lethal). An example of ammunition is the firearm Cartridge (firearms), cartridge, which includes all components required to deliver the weapon effect in a single package. Until the 20th century, black powder was the most common propellant used but has now been replaced in nearly all cases by modern compounds. Ammunition comes in a great range of sizes and types and is often designed to work only in specific weapons systems. However, there are internationally recognized standards for certain ammunition types (e.g., 5.56×45mm NA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Aerospace Science And Technology Corporation
The China Aerospace Science and Technology Corporation (CASC) is a main contractor for the Chinese space program. It is state-owned and has subsidiaries which design, develop and manufacture a range of spacecraft, launch vehicles, and ground equipment. It also has a division for strategic and tactical missile systems. History CASC was officially established in July 1999 as part of a Chinese government reform drive, having previously been one part of the former China Aerospace Corporation. Various incarnations of the program date back to 1956. Along with space and defense manufacture, CASC also produces machinery, chemicals, communications Communication is commonly defined as the transmission of information. Its precise definition is disputed and there are disagreements about whether Intention, unintentional or failed transmissions are included and whether communication not onl ... equipment, transportation equipment, computers, medical care products and Natural environm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apstar 2
APstar 2 (Asia-Pacific Star 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 January 26, 1995, by a Long March 2E launch vehicle from Xichang Satellite Launch Center in China, but was destroyed 51 seconds after liftoff when the rocket exploded. Falling debris from the rocket killed at least six villagers on the ground and injured 23. 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. Background A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hughes Aircraft Company
The Hughes Aircraft Company was a major American aerospace and defense contractor founded on February 14, 1934 by Howard Hughes in Glendale, California, as a division of the Hughes Tool Company. The company produced the Hughes H-4 Hercules aircraft, the atmospheric entry probe carried by the ''Galileo'' spacecraft, and the AIM-4 Falcon guided missile. Hughes Aircraft was founded to build Hughes' H-1 Racer world speed record aircraft, and later modified other aircraft for his transcontinental and global circumnavigation speed record flights. The company relocated to Culver City, California, in 1940 and began manufacturing aircraft parts as a subcontractor. Hughes attempted to mold it into a major military aircraft manufacturer during World War II. However, its early military projects ended in failure, with millions of dollars in U.S. government funds expended for only a handful of prototypes, resulting in a highly publicized U.S. Senate investigation into alleged mismanage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Earth Orbit
A low Earth orbit (LEO) is an geocentric orbit, orbit around Earth with a orbital period, period of 128 minutes or less (making at least 11.25 orbits per day) and an orbital eccentricity, eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, peaking in number at an altitude around , while the farthest in LEO, before medium Earth orbit (MEO), have an altitude of 2,000 km, about one-third of the Earth radius, radius of Earth and near the beginning of the Van Allen radiation belt#Inner belt, inner Van Allen radiation belt. The term ''LEO region'' is used for the area of space below an altitude of (about one-third of Earth's radius). Objects in orbits that pass through this zone, even if they have an apogee further out or are sub-orbital spaceflight, sub-orbital, are carefully tracked since they present a collision risk to the many LEO satellites. No human spaceflights other than the lunar missions of the Apollo program (1968-1972) have gone beyond L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Shear
Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal wind shear. Vertical wind shear is a change in wind speed or direction with a change in altitude. Horizontal wind shear is a change in wind speed with a change in lateral position for a given altitude. Wind shear is a microscale meteorological phenomenon occurring over a very small distance, but it can be associated with mesoscale or synoptic scale weather features such as squall lines and cold fronts. It is commonly observed near microbursts and downbursts caused by thunderstorms, fronts, areas of locally higher low-level winds referred to as low-level jets, near mountains, radiation inversions that occur due to clear skies and calm winds, buildings, wind turbines, and sailboats. Wind shear has significant effects on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optus (satellite)
This is a list of the satellites operated by Optus, an Australian telecommunications company. The satellite communications facility is located at Belrose on Sydney's Northern Beaches. Optus' satellites are divided into 4 classes A, B, C and D. As of April 2014 it owns and operates Optus B3, Optus C1, Optus D1, Optus D2 and Optus D3. Optus A1, Optus A2, Optus A3 and Optus B1 satellites have been retired. Optus has the largest network of satellites in Australia and New Zealand. On 2 February 2014, NBN Co of Australia chose Optus for a five-year contract to operate two purpose-built satellites (the Sky Muster satellites) to deliver high speed broadband across rural and remote Australia. A-Class *Satellite Type: Hughes HS-376 *Design Life: 7 Years for A1 & A2 – 10 Years for A3 *Equipment: 15 Ku band transponders (including four 30W transponders and eleven 12W transponders) *Diameter: 2.2m *Height: 2.9m (stowed), 6.3m (deployed) The Aussat A-Class satellites were funded by the Go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
