Technicians prepare to unpack and unveil the Aquarius/SAC-D spacecraft in the Spaceport Systems International payload processing facility at Vandenberg Air Force Base.

Technicians prepare to unpack and unveil the Aquarius/SAC-D spacecraft in the Spaceport Systems International payload processing facility at Vandenberg Air Force Base in California. The container protected the spacecraft on its journey from Campos, Brazil, aboard a U.S. Air Force C-17 transport plane. Following final tests, the spacecraft will be integrated to a United Launch Alliance Delta II rocket in preparation for the targeted June launch to low Earth orbit.

Aquarius, the NASA-built primary instrument on the SAC-D spacecraft, will map global changes in salinity at the ocean's surface. Salinity is a key measurement for understanding how changes in rainfall, evaporation and the melting of freezing of ice influence ocean circulation and are linked to variations in Earth's climate. The three-year mission will provide new insights into how variations in ocean surface salinity relate to these fundamental climate processes. Photo credit: NASA/Randy Beaudoin, VAFB