At Vandenberg Air Force Base in California the interstage of the United Launch Alliance Delta II arrives at NASA's Space Launch Complex-2.

At Vandenberg Air Force Base in California, the interstage of the United Launch Alliance Delta II that will carry NASA's National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) satellite into space arrives at NASA's Space Launch Complex-2.

The interstage provides an interface between the launch vehicle's first and second stages. NPP represents a critical first step in building the next-generation of Earth-observing satellites. NPP will carry the first of the new sensors developed for this satellite fleet, now known as the Joint Polar Satellite System (JPSS) to be launched in 2016. NPP is the bridge between NASA's Earth Observing System (EOS) satellites and the forthcoming series of JPSS satellites. The mission will test key technologies and instruments for the JPSS missions. For more information, visit http://www.nasa.gov/NPP. Photo credit: NASA/VAFB, Rudy Bledsoe