The Aquarius/SAC-D satellite launched on June 10, 2011, and was a joint venture between NASA and the Argentina National Space Activities Commission (CONAE). The mission featured the sea surface salinity sensor Aquarius and was the first mission with the primary goal of measuring sea surface salinity (SSS) from space. 

Data from Aquarius played a large role in understanding both climate change and the global water cycle. Aquarius/SAC-D carried three radiometers and one scatterometer operating at 1.4 GHz and 1.2 GHz, respectively. The data collected by the radiometer were used together with sea surface temperature collected from another platform(s) to derive salinity data, and corrected for surface roughness using data from the Aquarius scatterometer. 

On June 7, 2015, the Aquarius/SAC-D observatory suffered a mission-ending hardware failure resulting in the permanent cessation of data flows. The entire Aquarius data record spans a full 3-year, 9-month period from August 25, 2011, to June 7, 2015.