Workers guide the first stage of the United Launch Alliance Delta II rocket that will carry the Aquarius/SAC-D spacecraft.

With the aid of an overhead crane, workers guide the first stage of the United Launch Alliance Delta II rocket that will carry the Aquarius/SAC-D spacecraft into low Earth orbit, into 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, on its three-year mission, will provide new insights into how variations in ocean surface salinity relate to fundamental climate processes. Photo credit: NASA/VAFB