SAC-D (Spanish: Satelite de Aplicaciones Cientificas-D, meaning Satellite for Scientific Applications-D), also known as Aquarius after its primary instrument, is an Argentine Earth science satellite built by INVAP and launched on June 10, 2011. It carries seven instruments to study the environment, and a technology demonstration experiment.
Its primary instrument, Aquarius, was built by and is operated by the United States National Aeronautics and Space Administration.
SAC-D is operated by CONAE, the Argentine space agency. The satellite is expected to operate for five years; however the Aquarius instrument is only expected to operate for three.