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Molniya Orbit
A Molniya orbit ( rus, Молния, p=ˈmolnʲɪjə, a=Ru-молния.ogg, "Lightning") is a type of satellite orbit designed to provide communications and remote sensing coverage over high latitudes. It is a highly elliptical orbit with an inclination of 63.4 degrees, an argument of perigee of 270 degrees, and an orbital period of approximately half a sidereal day. The name comes from the ''Molniya'' satellites, a series of Soviet/Russian civilian and military communications satellites which have used this type of orbit since the mid-1960s. The Molniya orbit has a long dwell time over the hemisphere of interest, while moving very quickly over the other. In practice, this places it over either Russia or Canada for the majority of its orbit, providing a high angle of view to communications and monitoring satellites covering these high-latitude areas. Geostationary orbits, which are necessarily inclined over the equator, can only view these regions from a low angle, hamperin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA Molniya Oblique
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 for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equator
The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can also be used for any other celestial body that is roughly spherical. In spatial (3D) geometry, as applied in astronomy, the equator of a rotating spheroid (such as a planet) is the parallel (circle of latitude) at which latitude is defined to be 0°. It is an imaginary line on the spheroid, equidistant from its poles, dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid with the plane perpendicular to its axis of rotation and midway between its geographical poles. On and near the equator (on Earth), noontime sunlight appears almost directly overhead (no more than about 23° from the zenith) every day, year-round. Consequently, the equator has a rather stable daytime temperature throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meridian (satellite)
Meridian (Russian: Меридиан) is a family of telecommunications satellites for civil and military use developed by Russia in the 2000s placed in a Molniya Orbit and intended to replace the two last series of Molniya satellites still in activity, as well as the old Parus satellites. The first launch took place on 24 December 2006, aboard a Soyuz 2.1a. Seven satellites were launched between 2006 and 2014, six of which reached orbit. A second generation of satellite, Meridian-M was ordered, and the first unit was launched on 30 July 2019. Technical characteristics This family of satellites was developed in the mid-2000s by the main Russian satellite manufacturer ISS Reshetnev who had already built the Molniya satellites. According to unofficial sources, the satellite uses 3 axes stabilized pressurized platform. Certain components like the on-board computer and the propulsion would be common with the Uragan-M satellites of the Glonass satellite navigation system. The manufactu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Network
A television network or television broadcaster is a telecommunications network for distribution of television program content, where a central operation provides programming to many television stations or multichannel video programming distributor, pay television providers. Until the mid-1980s, television broadcast programming, programming in most countries of the world was dominated by a small number of terrestrial networks. Many early television networks (such as NBC, the Australian Broadcasting Corporation, ABC, or the BBC) evolved from earlier radio networks. Overview In countries where most networks broadcast identical, centrally originated content to all of their stations and where most individual television transmitters therefore operate only as large "broadcast relay station, repeater stations", the terms "television network", "television channel" (a numeric identifier or radio frequency) and "television station" have become mostly interchangeable in everyday language, wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbita (TV System)
Orbita (russian: орбита) is a Soviet-Russian system of broadcasting and delivering TV signals via satellites. It is considered to be the first national network of satellite television. The Orbita system is based on communication satellites in highly elliptical Molniya orbits, as well as on many ground downlink TV stations for reception and relaying TV signals to antennas of TV sets of many local areas. The full deployment of the Orbita satellite system took place on 25 October 1967 when ground downlink stations of some cities of Soviet Siberia and the Far East began to receive regular TV programmes from Moscow-based uplink stations via a constellation A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellation ... of Molniya satellites. External linksMolniya satellites : the descrip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Perturbation Analysis
In astronomy, perturbation is the complex motion of a massive body subjected to forces other than the gravitational attraction of a single other massive body. The other forces can include a third (fourth, fifth, etc.) body, resistance, as from an atmosphere, and the off-center attraction of an oblate or otherwise misshapen body. Introduction The study of perturbations began with the first attempts to predict planetary motions in the sky. In ancient times the causes were unknown. Isaac Newton, at the time he formulated his laws of motion and of gravitation, applied them to the first analysis of perturbations, recognizing the complex difficulties of their calculation. Many of the great mathematicians since then have given attention to the various problems involved; throughout the 18th and 19th centuries there was demand for accurate tables of the position of the Moon and planets for marine navigation. The complex motions of gravitational perturbations can be broken down. The h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of The British Interplanetary Society
The ''Journal of the British Interplanetary Society'' (''JBIS'') is a monthly peer-reviewed scientific journal that was established in 1934. The journal covers research on astronautics and space science and technology, including spacecraft design, nozzle theory, launch vehicle design, mission architecture, space stations, lunar exploration, spacecraft propulsion, robotic and manned exploration of the solar system, interstellar travel, interstellar communications, extraterrestrial intelligence, philosophy, and cosmology. It is published monthly by the British Interplanetary Society. History The journal was established in 1934 when the British Interplanetary Society was founded. The inaugural editorial stated: ''The ultimate aim of the society, of course, is the conquest of space and thence interplanetary travel.....(the) immediate task is the stimulation of public interest in the subject of interplanetary travel and the dissemination of knowledge concerning the true nature of the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zenit (satellite)
Zenit (russian: link=no, Зени́т, , Zenith) was a series of military photoreconnaissance satellites launched by the Soviet Union between 1961 and 1994. To conceal their nature, all flights were given the public Kosmos designation. Description The basic design of the Zenit satellites was similar to the Vostok manned spacecraft, sharing the return and service modules. It consisted of a spherical re-entry capsule in diameter with a mass of around . This capsule contained the camera system, its film, recovery beacons, parachutes and a destruct charge. In orbit, this was attached to a service module that contained batteries, electronic equipment, an orientation system and a liquid-fuelled rocket engine that would slow the Zenit for re-entry, before the service module detached. The total length in orbit was around and the total mass was between . Unlike the American CORONA spacecraft, the return capsule carried both the film and the cameras and kept them in a temperature- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Institute Of Aeronautics And Astronautics
The American Institute of Aeronautics and Astronautics (AIAA) is a professional society for the field of aerospace engineering. The AIAA is the U.S. representative on the International Astronautical Federation and the International Council of the Aeronautical Sciences. In 2015, it had more than 30,000 members among aerospace professionals worldwide (a majority are American and/or live in the United States). History The AIAA was founded in 1963 from the merger of two earlier societies: the American Rocket Society (ARS), founded in 1930 as the American Interplanetary Society (AIS), and the Institute of the Aerospace Sciences (IAS), founded in 1932 as the Institute of the Aeronautical Sciences. Paul Johnston was the first executive director of the organization. Jim Harford took his seat after 18 months. The newly-formed structure gathered 47 technical committees and one broad technical publication, the ''AIAA Journal''. The ''AIAA Student Journal'' was also launched in 1963. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apogee
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] |
Energia (corporation)
PAO S. P. Korolev Rocket and Space Corporation Energia (russian: Ракетно-космическая корпорация «Энергия» им. С. П. Королёва, Raketno-kosmicheskaya korporatsiya "Energiya" im. S. P. Korolyova), also known as RSC Energia (, RKK "Energiya"), is a Russian manufacturer of spacecraft and space station components. The company is the prime developer and contractor of the Russian crewed spaceflight program; it also owns a majority of Sea Launch. Its name is derived from Sergei Korolev, the first chief of its design bureau, and the Russian word for energy. Overview Energia is the largest company of the Russian space industry and one of its key players. It is responsible for all operations involving human spaceflight and is the lead developer of the Soyuz and Progress spacecraft, and the lead developer of the Russian end of the International Space Station (ISS). In the mid-2000s, the company employed 22,000–30,000 people. The ent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination Change
Orbital inclination change is an orbital maneuver aimed at changing the inclination of an orbiting body's orbit. This maneuver is also known as an orbital plane change as the plane of the orbit is tipped. This maneuver requires a change in the orbital velocity vector (delta-v) at the orbital nodes (i.e. the point where the initial and desired orbits intersect, the line of orbital nodes is defined by the intersection of the two orbital planes). In general, inclination changes can take a very large amount of delta-v to perform, and most mission planners try to avoid them whenever possible to conserve fuel. This is typically achieved by launching a spacecraft directly into the desired inclination, or as close to it as possible so as to minimize any inclination change required over the duration of the spacecraft life. Planetary flybys are the most efficient way to achieve large inclination changes, but they are only effective for interplanetary missions. Efficiency The simplest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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