IMAGE PROVIDED BY NASA SHOWING AN ARTIST'S CONCEPTION. AP PROVIDES ACCESS TO THIS PUBLICLY DISTRIBUTED HANDOUT IMAGE PROVIDED BY NASA
This image provided by NASA shows an artist's conception 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. (AP Photo/NASA)