At Astrotech Space Operations in Titusville Fla. workers begin mating the STEREO spacecraft onto the upper stage booster.

At Astrotech Space Operations in Titusville, Fla., workers begin mating the STEREO spacecraft onto the upper stage booster below. After the mating, they will be transported to Launch Pad 17-B at Cape Canaveral Air Force Station for integration with the Delta II already on the pad. STEREO stands for Solar Terrestrial Relations Observatory and comprises two spacecraft. The STEREO mission is the first to take measurements of the sun and solar wind in 3-dimension. This new view will improve our understanding of space weather and its impact on the Earth. STEREO is expected to lift off Aug. 31. Photo credit: NASA/George Shelton