Inside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, the second stage of the Boeing Delta II launch vehicle for the STEREO spacecraft is lowered toward the Delta first stage below for remating. The second stage has been returned to the pad after being tested for leaks in the High-Pressure Test Facility; no leak was observed. 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 on Aug. 31. Photo credit: NASA/Dimitri Gerondidakis