LEO > Low Earth Orbit > Polar Sun-Synchronous
[Text from the NPP Launch Blog, http://www.nasa.gov/mission_pages/NPP/launch/launch_blog.html
The NPOESS Preparatory Project (NPP) spacecraft lifted off aboard a United Launch Alliance Delta II ... rocket from Space Launch Complex 2 at Vandenberg Air Force Base in California on Oct. 28, 2011 at 5:48 a.m. EDT.
The NPP spacecraft will build on more than four decades Earth observation to help us better understand our climate.
[Text and Image Source, NPOESS Preparatory Project home page, http://npp.gsfc.nasa.gov/ ]
The National Polar-Orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) is a joint mission involving the National Aeronautics and Space Administration's (NASA) and the NPOESS Integrated Program Office (IPO).
The NPP mission collects and distributes remotely-sensed land, ocean, and atmospheric data to the meteorological and global climate change communities as the responsibility for these measurements transitions from existing Earth-observing missions such as Aqua, Terra and Aura, to the NPOESS. It will provide atmospheric and sea surface temperatures, humidity sounding, land and ocean biological productivity, and cloud and aerosol properties.
For the IPO, NPP provides risk reduction with an opportunity to demonstrate and validate new instruments and processing algorithms, as well as to demonstrate and validate aspects of the NPOESS command, control, communications and ground processing capabilities prior to the launch of the first NPOESS spacecraft.