The Aquarius/SAC-D mission, launched on 10 June 2011, was a joint venture between NASA and the Argentinean Space Agency (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. This instrument carried 3 radiometers and 1 scatterometer operating at 1.4 GHz & 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 7 June 2015 at 12:53:17 UTC 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 25 August 2011 to 7 June 2015.