SAC-D/Aquarius

SAC-D/Aquarius (Satélite de Aplicaciones Científicas D) was a joint Earth observation mission developed by Argentina’s CONAE and NASA. Launched on June 10, 2011 aboard a Delta II rocket from Vandenberg Air Force Base, the satellite operated until June 2015 when it lost power.

The flagship instrument was NASA’s Aquarius radiometer/scatterometer, which measured global sea surface salinity (SSS) at a spatial resolution of approximately 150 km — the first time a dedicated space mission mapped ocean salinity from orbit. Sea surface salinity data is critical for understanding ocean circulation, the global water cycle, and climate variability.

CONAE contributed the SAC-D spacecraft bus (built by INVAP) and seven additional scientific instruments, including the MWR (Microwave Radiometer) for soil moisture and sea ice studies, NIRST (New InfraRed Sensor Technology), CARMEN/ICARE for radiation environment monitoring, DCS (Data Collection System), and HSC (High Sensitivity Camera) for nighttime imagery of urban areas and fires.

The mission was part of NASA’s Earth System Science Pathfinder program and demonstrated the successful model of international cooperation between Argentina and the United States in space science.