The first Laser Geodynamics Satellite spacecraft, known as LAGEOS-I, was launched on May 4,1976 by a three-stage Delta rocket from the Western Test Range in California into a 6000 km near-circular orbit with an inclination of 110 degrees. The objective of the LAGEOS-I Mission is the accurate measurement of the movements of the Earth's crust and the Earth's rotational motions by laser ranging techniques. The LAGEOS-I spacecraft is a brass and aluminum, sphere, 60 cm. in diameter, weighing 411 kg and carries and an array of 426 laser retroreflectors. The spacecraft is completely inert, containing no moving parts or electronic equipment and is designed to have a very stable orbit that can be determined with very high accuracy. Major accomplishments obtained from laser tracking of LAGEOS-I are the measurement of distances between points on the Earths surfaces to about 5 cm., the measurement of the Earths rotation to approximately 0.006 arcseconds in position and 0.1 milliseconds in the length of day, and a significant improvement in our knowledge of the long wavelength components of the Earth s gravity field and of the ocean tides. In April 1982 the National Aeronautics and Space Administration and the Consiglio Nazionale delle Ricerche/Piano Spaziale Nazionale (CNR/PSN), later to become the Italian Space Agency, Agenzia Spaziale Italiana, (ASI), agreed to establish a Joint Study Group to consider the scientific value of launching a second LAGEOS spacecraft to support national and international programs in geodynamics research. The Joint Study Group confirmed that a second satellite could significantly enhance study and understanding of the solid earth and its dynamic processes. It strongly recommended that a second LAGEOS (LAGEOS-II) be launched, that LAGEOS-II be the same physical size, mass and construction as LAGEOS-I, that its optical transfer characteristics and reflectivity be measured prior to launch, and that LAGEOS-II be launched into a near-circular orbit at an altitude of 5900 km with an orbital inclination of 52 degrees.


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    Title :

    Laser Geodynamics Satellite-II/Italian Research Interim Stage (LAGEOS-II/IRIS) Prelaunch Mission Operations Report


    Publication date :

    1982


    Size :

    68 pages


    Type of media :

    Report


    Type of material :

    No indication


    Language :

    English





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