The first stage of the Boeing Delta II rocket slated to launch NASA's Solar Terrestrial Relations Observatory arrives at Pad 17B.

The first stage of the Boeing Delta II rocket, slated to launch NASA's Solar Terrestrial Relations Observatory (STEREO), arrives at Pad 17B on Cape Canaveral Air Force Station. Preparations are under way for a liftoff no earlier than July 22. STEREO consists of two spacecraft whose mission is the first to take measurements of the sun and solar wind in 3-D. This new view will improve our understanding of space weather and its impact on the Earth. Photo credit: NASA/Jim Grossmann