Aquarius makes first ocean salt measurements

NASA: NASA's Aquarius instrument has successfully completed its commissioning phase and is now "tasting" the saltiness of Earth's ocean surface, making measurements from its perch in near-polar orbit. "This marks the end of the long odyssey to design, build and launch this mission, and the start of a new journey of scientific exploration," said Aquarius Principal Investigator Gary Lagerloef of Earth & Space Research, Seattle. "Scientists from around the world are ready and waiting to study this important new satellite measurement for ocean and climate research."

The Aquarius/SAC-D (Satélite de Aplicaciones Científicas) observatory, a collaboration between NASA and Argentina's space agency, Comisión Nacional de Actividades Espaciales (CONAE), launched from California's Vandenberg Air Force Base on June 10 aboard a United Launch Alliance Delta II rocket and was placed in its proper initial orbit. Ground controllers at the SAC-D Mission Operations Center in Teófilo Tabanera Space Center in Cordoba, Argentina, then began a complete in-orbit checkout of all SAC-D spacecraft systems.

With all observatory systems confirmed to be healthy, SAC-D spacecraft commissioning activities were completed on July 24. The spacecraft's propulsion system then underwent a series of tests, and preliminary orbit adjustments were performed in preparation for turning on the observatory's eight science instruments.

Aquarius will make NASA's first space observations of the salinity, or concentration of salt, at the ocean surface, a key variable in satellite studies of Earth. Variations in salinity influence the ocean's deep circulation, outline the path freshwater takes around our planet and help drive Earth's climate....

Artist's concept of the Aquarius/SAC-D spacecraft, a collaboration between NASA and Argentina's space agency, with participation from Brazil, Canada, France and Italy. Aquarius, the NASA-built primary instrument on the spacecraft, will take NASA's first space-based measurements of ocean surface salinity, a key missing variable in satellite observations of Earth that links ocean circulation, the global balance of freshwater and climate. The mission is scheduled to launch in June. Image credit: NASA