TOPEX/Poseidon was a joint satellite altimeter mission between NASA, the U.S. space agency; and CNES, the French space agency, to map ocean surface topography. Launched on August 10, 1992, it was the first major oceanographic research satellite. TOPEX/Poseidon helped revolutionize oceanography by providing data previously impossible to obtain. Oceanographer Walter Munk described TOPEX/Poseidon as "the most successful ocean experiment of all time." A malfunction ended normal satellite operations in January 2006. Description Before TOPEX/Poseidon, scientists had only a brief glimpse of Earth's ocean as a whole from the pioneering but short-lived Seasat satellite. TOPEX/Poseidon's radar altimeter provided the first continuous global coverage of the surface topography of the oceans. From orbit 1,330 kilometers above Earth, TOPEX/Poseidon provided measurements of the surface height of 95 percent of the ice-free ocean to an accuracy of 3.3 centimeters. The satellite's measurements of the hills and valleys of the sea surface led to a fundamentally new understanding of ocean circulation and its effect on climate. Goal The mission's most important achievement was to determine the patterns of ocean circulation - how heat stored in the ocean moves from one place to another. Since the ocean holds most of the Earth's heat from the Sun, ocean circulation is a driving force of climate. TOPEX/Poseidon made it possible for the first time to compare computer models of ocean circulation with actual global observations and use the data to improve climate predictions. Results While a three-year prime mission was planned, TOPEX/Poseidon delivered more than 10 years of data from orbit. In those years, the mission: Measured sea level with an unprecedented accuracy Mapped global tides for the first time Monitored effects of currents on global climate change and produced the first global views of seasonal changes of currents Monitored large-scale ocean features like Rossby and Kelvin waves and studied such phenomena as El Niño, La Niña, and the Pacific Decadal Oscillation Mapped basin-wide current variations and provided global data to validate models of ocean circulation Mapped year-to-year changes in heat stored in the upper ocean Improved our knowledge of Earth's gravity field Observed the temperature of the ocean and main seas for over a period of 10 years TOPEX/Poseidon was launched using an Ariane 42P expendable launch vehicle, along with Korea Institute of Technology's Kitsat-1 satellite and France's S80/T satellite . Lift-off from Kourou in French Guiana took place on 1992-08-10. At lift-off the mass of the