The first stage of a United Launch Alliance Delta II is lowered into place on Vandenberg Air Force Base in California.

The first stage of a United Launch Alliance Delta II is lowered into place at NASA's Space Launch Complex-2 on Vandenberg Air Force Base in California. Seen here in red is the Rocketdyne engine that will help loft the rocket off the pad. The rocket will carry NASA's National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) satellite into space.

NPP will be positioned 512 miles above the Earth's surface and will orbit about 16 times each day to observe nearly the entire globe. The NPP mission for NASA and the National Oceanic and Atmospheric Administration (NOAA) is to measure Earth's atmospheric and sea surface temperatures, humidity sounding, land and ocean biological activity, and cloud and aerosol properties. For more information, visit www.nasa.gov/NPP. Photo credit: NASA/VAFB, Mark Mackley