History
Laser ranging to a near-Earth satellite was first carried out by NASA in 1964 with the launch of the Beacon-B satellite. Since that time, ranging precision, spurred by scientific requirements, has improved by a factor of a thousand from a few metres to a few millimetres, and more satellites equipped with retroreflectors have been launched.
Several sets of retroreflectors were installed on the Earth's moon as part of the American Apollo and Soviet Lunokhod space programs. These retroreflectors are also ranged on a regular basis, providing a highly accurate measurement of the dynamics of the Earth/Moon system.
During the subsequent decades, the global satellite laser ranging network has evolved into a powerful source of data for studies of the solid Earth and its ocean and atmospheric systems. In addition, SLR provides precise orbit determination for spaceborne radar altimetre missions mapping the ocean surface (which are used to model global ocean circulation), for mapping volumetric changes in continental ice masses, and for land topography. It provides a means for subnanosecond global time transfer, and a basis for special tests of the Theory of General Relativity.
The International Laser Ranging Service was formed in 1998 by the global SLR community to enhance geophysical and geodetic research activities, replacing the previous CSTG Satellite and Laser Ranging Subcommission.
Read more about this topic: Satellite Laser Ranging
Famous quotes containing the word history:
“The visual is sorely undervalued in modern scholarship. Art history has attained only a fraction of the conceptual sophistication of literary criticism.... Drunk with self-love, criticism has hugely overestimated the centrality of language to western culture. It has failed to see the electrifying sign language of images.”
—Camille Paglia (b. 1947)
“In every election in American history both parties have their clichés. The party that has the clichés that ring true wins.”
—Newt Gingrich (b. 1943)
“For a transitory enchanted moment man must have held his breath in the presence of this continent, compelled into an aesthetic contemplation he neither understood nor desired, face to face for the last time in history with something commensurate to his capacity for wonder.”
—F. Scott Fitzgerald (1896–1940)