Workers attach one of three solid rocket motors to a United Launch Alliance Delta II launch vehicle at Vandenberg Air Force Base in California.

Workers attach one of three solid rocket motors to a United Launch Alliance Delta II launch vehicle in the service tower at NASA's Space Launch Complex-2 (SLC-2) at Vandenberg Air Force Base in California.

Following final tests, the spacecraft will be integrated to the Delta II in preparation for the targeted June launch. Aquarius, the NASA-built instrument on the SAC-D spacecraft will provide new insights into how variations in ocean surface salinity relate to fundamental climate processes on its three-year mission. Photo credit: NASA/VAFB