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International Laser Ranging Service
In satellite laser ranging (SLR) a global network of observation stations measures the round trip time of flight of ultrashort pulses of light to satellites equipped with retroreflectors. This provides instantaneous range measurements of millimeter level precision which can be accumulated to provide accurate measurement of orbits and a host of important scientific data. The laser pulse can also be reflected by the surface of a satellite without a retroreflector, which is used for tracking space debris. Satellite laser ranging is a proven geodetic technique with significant potential for important contributions to scientific studies of the earth/atmosphere/ocean system. It is the most accurate technique currently available to determine the geocentric position of an Earth satellite, allowing for the precise calibration of radar altimeters and separation of long-term instrumentation drift from secular changes in ocean topography. Its ability to measure the variations over time in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STARSHINE (satellite)
The STARSHINE (Student Tracked Atmospheric Research Satellite Heuristic International Networking Experiment) series of three (later, a fourth one was also launched) artificial satellites were student participatory missions sponsored by the United States Naval Research Laboratory (the fourth STARSHINE was a NASA mission). Satellite description STARSHINE-1 was a spherical satellite that was fitted with almost nine hundred small mirrors polished by students from around the world. Once launched, a network of over 20,000 students from eighteen countries tracked the satellite by observing sunlight glinting off the mirrors and networked their observations via the Internet. The students used these observations to calculate air drag, solar activity, and other orbit related properties of the satellite. STARSHINE 2 and 3 had systems added to impart spin to these satellites in an effort to improve the solar-reflected flash rate, as well as a number of laser retroreflectors to introduce the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LARES (satellite)
LARES (Laser Relativity Satellite) is a passive satellite system of the Italian Space Agency. Mission Launch LARES was launched into orbit on 13 February 2012 at 10:00:00 UTC. It was launched on the first Vega rocket from the ESA Centre Spatial Guyanais in Kourou, French Guiana. Composition The satellite is made of THA-18N, a tungsten alloy, and houses 92 cube-corner retroreflectors, which are used to track the satellite via laser from stations on Earth. LARES's body has a diameter of about and a mass of about . LARES was inserted in a nearly circular orbit near and an inclination of 69.49 degrees. The satellite is tracked by the International Laser Ranging Service stations. The LARES satellite is the densest object known orbiting the Earth. The high density helps reduce disturbances from environmental factors such as solar radiation pressure. Scientific goals The main scientific target of the LARES mission is the measurement of the Lense–Thirring effect with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STS-52
STS-52 was a ''Space Transportation System'' ( NASA Space Shuttle) mission using Space Shuttle ''Columbia'', and was launched on October 22, 1992. Crew Backup crew Mission highlights Primary mission objectives were deployment of the Laser Geodynamics Satellite 2 ( LAGEOS-2) and operation of the U.S. Microgravity Payload-1 (USMP-1). LAGEOS 2, a joint effort between NASA and the Italian Space Agency (ASI), was deployed on day 2 and boosted into an initial elliptical orbit by ASI's Italian Research Interim Stage (IRIS). The spacecraft's apogee kick motor later circularized LAGEOS 2 orbit at its operational altitude of . The USMP-1, activated on day one, included three experiments mounted on two connected Mission Peculiar Equipment Support Structures (MPESS) mounted in the orbiter's cargo bay. USMP-1 experiments were: Lambda Point Experiment; Matériel pour l'Étude des Phénomènes Intéressant la Solidification sur eT en Orbite (MEPHISTO), sponsored by the French agen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LAGEOS
LAGEOS, Laser Geodynamics Satellite or Laser Geometric Environmental Observation Survey, are a series of two scientific research satellites designed to provide an orbiting laser ranging benchmark for geodynamical studies of the Earth. Each satellite is a high-density passive laser reflector in a very stable medium Earth orbit (MEO). Function and operation The spacecraft are aluminum-covered brass spheres with diameters of and masses of , covered with 426 cube-corner retroreflectors, giving them the appearance of giant golf balls. Of these retroreflectors, 422 are made from fused silica glass while the remaining 4 are made from germanium to obtain measurements in the infrared for experimental studies of reflectivity and satellite orientation. They have no on-board sensors or electronics, and are not attitude-controlled. They orbit at an altitude of , well above low Earth orbit and well below geostationary orbit, at orbital inclinations of 109.8 and 52.6 degrees. Measurements ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Etalon (satellite) (MEO).
Etalon-1 and Etalon-2 are geodetic satellites. They are designed to determine, with high accuracy, terrestrial reference frame and earth rotation parameters, to improve the gravity field, and to improve the gravitational constant. Each satellite is a high-density passive laser reflector in a very stable medium Earth orbit A medium Earth orbit (MEO) is an geocentric orbit, Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level. References {{reflist Geodetic satellites Laser ranging satellites[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experimental Geodetic Payload
Ajisai (Japanese: あじさい, meaning "Hydrangea") is a Japanese satellite sponsored by NASDA, launched in 1986 on the first flight of the H-I rocket. It is also known as the Experimental Geodetic Satellite (EGS), as it carried the Experimental Geodetic Payload (EGP). History EGP was launched from the Tanegashima Space Center on August 12, 1986 at 20:45 GMT (August 13, 05:45 local time). The launch vehicle was the first H-I rocket. After launch, the spacecraft was given the International Designator 1986-061A and Satellite Catalog Number 16908. Structure EGP is entirely passive, and operates by reflecting sunlight or ground-based lasers.Curtis, Anthony R (1989). ''Space Almanac,'' Arcsoft Publishers. The satellite is a 685-kg hollow sphere with a diameter of 2.15 meters, and the surface is covered with 318 mirrors for reflecting sunlight and 1436 corner reflectors for reflecting laser beams. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BLITS
BLITS (Ball Lens In The Space) is a Russian satellite launched on September 17, 2009, as a secondary payload on a Soyuz-2.1b/Fregat, from the Baikonur Cosmodrome in Kazakhstan. The satellite is totally passive and spherical, and is tracked using satellite laser ranging (SLR) by the International Laser Ranging Service. The design of BLITS is based on the optical Luneburg lens concept. The retroreflector is a multilayer glass sphere; it provides uniform reflection characteristics when viewed within a very wide range of angles, and can provide a cross-section sufficient for observations at low to medium orbit heights. A similar design was already tested on a smaller laser reflector carried on board of the METEOR-3M spacecraft launched on December 10, 2001. The purpose of the mission was to validate the spherical glass retroreflector satellite concept and obtain SLR (Satellite Laser Ranging) data for solution of scientific problems in geophysics, geodynamics, and relativity. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ajisai (satellite)
Ajisai (Japanese: あじさい, meaning "Hydrangea") is a Japanese satellite sponsored by NASDA, launched in 1986 on the first flight of the H-I rocket. It is also known as the Experimental Geodetic Satellite (EGS), as it carried the Experimental Geodetic Payload (EGP). History EGP was launched from the Tanegashima Space Center on August 12, 1986 at 20:45 GMT (August 13, 05:45 local time). The launch vehicle was the first H-I rocket. After launch, the spacecraft was given the International Designator 1986-061A and Satellite Catalog Number 16908. Structure EGP is entirely passive, and operates by reflecting sunlight or ground-based lasers.Curtis, Anthony R (1989). ''Space Almanac,'' Arcsoft Publishers. The satellite is a 685-kg hollow sphere with a diameter of 2.15 meters, and the surface is covered with 318 mirrors for reflecting sunlight and 1436 corner reflectors for reflecting laser beams. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geoid
The geoid () is the shape that the ocean surface would take under the influence of the gravity of Earth, including gravitational attraction and Earth's rotation, if other influences such as winds and tides were absent. This surface is extended through the continents (such as with very narrow hypothetical canals). According to Carl Friedrich Gauss, Gauss, who first described it, it is the "mathematical figure of the Earth", a smooth but irregular surface whose shape results from the uneven distribution of mass within and on the surface of Earth. It can be known only through extensive gravitational measurements and calculations. Despite being an important concept for almost 200 years in the history of geodesy and geophysics, it has been defined to high precision only since advances in satellite geodesy in the late 20th century. All points on a geoid surface have the same geopotential (the sum of gravitational energy, gravitational potential energy and centrifugal force, centrifug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
