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Ofek Avital
Ofeq, also spelled Offek or Ofek ( he, אופק, ''lit.'' Horizon) is the designation of a series of Israeli reconnaissance satellites first launched in 1988. Most Ofeq satellites have been carried on top of Shavit 2 launch vehicles from Palmachim Airbase in Israel, on the Mediterranean coast. The low Earth orbit satellites complete one Earth orbit every 90 minutes. The satellite launches made Israel the eighth nation to gain an indigenous launch capability. Both the satellites and the launchers were designed and manufactured by Israel Aerospace Industries (IAI) with Elbit Systems' El-Op division supplying the optical payload. Description While exact technical details and capabilities are classified, it is assumed that the Ofeq satellites have an effective operational lifespan of 1–3 years and ultraviolet and visible imaging sensors (except Ofeq-8 and -10 which utilize synthetic-aperture radar (SAR) for all-weather and nighttime reconnaissance). Some reports place the ima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ofeq-7
Ofeq-7, (also known as Ofek 7 or Offek-7), is part of the Ofeq family of Earth observation satellites designed and built by Israel Aerospace Industries (IAI) for the Israel Ministry of Defense. Launch The Ofeq-7 was launched by a Shavit 2 space launch vehicle on 10 June 2007 at 23:40 UTC. Equipped with advanced technology and a series of new enhancements to provide improved imagery, it is placed into an elliptical orbit In astrodynamics or celestial mechanics, an elliptic orbit or elliptical orbit is a Kepler orbit with an eccentricity of less than 1; this includes the special case of a circular orbit, with eccentricity equal to 0. In a stricter sense, it ... of . Mission Three days after its launch, on 13 June 2007, IAI MBT Space Division received the first images taken by the satellite. The Ofeq-7 is a follow-on spacecraft to Ofeq-5 that was placed into orbit in 2002. References Reconnaissance satellites of Israel Spacecraft launched in 2007 Spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visible Spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visual perception, visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' or simply light. A typical human eye will respond to wavelengths from about 380 to about 750 nanometers. In terms of frequency, this corresponds to a band in the vicinity of 400–790 Terahertz (unit), terahertz. These boundaries are not sharply defined and may vary per individual. Under optimal conditions these limits of human perception can extend to 310 nm (ultraviolet) and 1100 nm (near infrared). The optical spectrum is sometimes considered to be the same as the visible spectrum, but some authors define the term more broadly, to include the ultraviolet and infrared parts of the electromagnetic spectrum as well. The spectrum does not contain all the colors that the human visual system can distinguish. ''Excitation purity, Unsaturated colors'' such as pink, or ... [...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] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope thermoelectric generators (RTGs). Most satellites also have a method of communication to ground stations, called Transponder (satellite communications), transponders. Many satellites use a Satellite bus, standardized bus to save cost and work, the most popular of which is small CubeSats. Similar satellites can work together as a group, forming Satellite constellation, constellations. Because of the high launch cost to space, satellites are designed to be as lightweight and robust as possible. Most communication satellites are radio Broadcast relay station, relay stations in orbit and carry dozens of transponders, each with a bandwidth of tens of megahertz. Satellites are placed from the surface to orbit by launch vehicles, high enough to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of NRO Launches
This is a list of NRO Launch (NROL) designations, i.e. satellites operated by the United States National Reconnaissance Office. Those missions are generally classified, so that their exact purposes and orbital elements are not published. However, amateur astronomers have managed to observe most of the satellites, and leaked information has led to the identification of many of the payloads. Launch statistics Launch vehicle families Launch sites Launch history See also * List of USA satellites References External links National Security Space Launch Report (pages 112) {{DEFAULTSORT:List Of Nro Satellites National Reconnaissance Office satellites, * NRO NRO may stand for: * National Reconciliation Ordinance, a Pakistani law * National Reconnaissance Office, maintains United States reconnaissance * National Repertory Orchestra, in Colorado * ''National Review Online'', web version of the magazine ... Secret space vehicles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrograde And Prograde Motion
Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is, the central object (right figure). It may also describe other motions such as precession or nutation of an object's rotational axis. Prograde or direct motion is more normal motion in the same direction as the primary rotates. However, "retrograde" and "prograde" can also refer to an object other than the primary if so described. The direction of rotation is determined by an inertial frame of reference, such as distant fixed stars. In the Solar System, the orbits around the Sun of all planets and most other objects, except many comets, are prograde. They orbit around the Sun in the same direction as the sun rotates about its axis, which is counterclockwise when observed from above the Sun's north pole. Except for Venus and Uranus, planetary rotations around their axes are also prograde. Most natural satellites have prograde or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sun-synchronous Orbit
A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is an orbit arranged so that it precesses through one complete revolution each year, so it always maintains the same relationship with the Sun. Applications A Sun-synchronous orbit is useful for imaging, reconnaissance, and weather satellites, because every time that the satellite is overhead, the surface illumination angle on the planet underneath it is nearly the same. This consistent lighting is a useful characteristic for satellites that image the Earth's surface in visible or infrared wavelengths, such as weather and spy satellites, and for other remote-sensing satellites, such as those carrying ocean and atmospheric remote-sensing instruments that require sunlight. For example, a satellite in Sun-synchronous orbit might ascend acros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geo-IK-2
The Geo-IK-2 is a Russian series of new generation military geodesy satellites replacing the Soviet Union's Geo-IK and Sfera constellations. They are intended to be used to create high precision three-dimensional maps of the Earth's surface, and to monitor plate tectonics. The satellites are produced by ISS Reshetnev, and have a mass of around . They operate in a circular orbit at an altitude of around above the Earth's surface. Not to be confused with the Napryazhenie / 14F150 / Nivelir military geodesy satellites. Launches See also * Satellite geodesy Satellite geodesy is geodesy by means of artificial satellites—the measurement of the form and dimensions of Earth, the location of objects on its surface and the figure of the Earth's gravity field by means of artificial satellite techniques ... * List of Kosmos satellites (2501–2750) References Earth observation satellites of Russia Geodetic satellites Kosmos satellites {{satellite-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KH-11 KENNEN
The KH-11 KENNEN (later renamed CRYSTAL,p.199-200 then Evolved Enhanced CRYSTAL System, and codenamed 1010 and Key Hole) is a type of reconnaissance satellite first launched by the American National Reconnaissance Office (NRO) in December 1976. Manufactured by Lockheed in Sunnyvale, California, the KH-11 was the first American spy satellite to use electro-optical digital imaging, and so offer real-time optical observations. Later KH-11 satellites have been referred to by outside observers as KH-11B or KH-12, and by the names "Advanced KENNEN", "Improved Crystal" and "Ikon". Official budget documents refer to the latest generation of electro-optical satellites as ''Evolved Enhanced CRYSTAL System''. The Key Hole series was officially discontinued in favor of a random numbering scheme after repeated public references to KH-7 GAMBIT, KH-8 GAMBIT 3, KH-9 HEXAGON, and KH-11 KENNEN satellites. The capabilities of the KH-11 are highly classified, as are images they produce. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (European part of Turkey), Egypt, Iran, the Levant (including Syria (region), Ash-Shām and Cyprus), Mesopotamia (modern-day Iraq), and the Socotra Governorate, Socotra Archipelago (a part of Yemen). The term came into widespread usage as a replacement of the term Near East (as opposed to the Far East) beginning in the early 20th century. The term "Middle East" has led to some confusion over its changing definitions, and has been viewed by some to be discriminatory or too Eurocentrism, Eurocentric. The region includes the vast majority of the territories included in the closely associated definition of Western Asia (including Iran), but without the South Caucasus, and additionally includes all of Egypt (not just the Sina ... [...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] |
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