Workers prepare the United Launch Alliance Delta II second stage motor at Vandenberg Air Force Base in California.

Workers prepare the United Launch Alliance Delta II second stage motor for lifting into the service tower at NASA's Space Launch Complex-2 (SLC-2) at Vandenberg Air Force Base in California.

Following final tests, the Aquarius/SAC-D spacecraft will be integrated to the Delta II launch vehicle in preparation for the targeted June liftoff. 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