NASA's Aquarius Sees Salty Shifts. The complete first year dataset of NASA's Aquarius instrument reveals seasonal changes in the Amazon River's plume. Depending on the prevailing currents, the river's freshwater outflow heads east toward Africa or bends up north to the Caribbean. Launched June 10, 2011, onboard the Argentinian spacecraft Aquarius/Sat矇lite de Aplicaciones Cient穩ficas (SAC)-D, Aquarius is NASA's first satellite instrument specifically designed to study the salt content of ocean surface waters. Salinity variations, one of the main drivers of ocean circulation, are closely connected with the cycling of freshwater around the planet and provide scientists with valuable information on how the changing global climate is altering global rainfall patterns.