The Suomi National Polar-orbiting Partnership, previously known as the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) and NPP-Bridge, is a weather satellite operated by the United States National Oceanic and Atmospheric Administration (NOAA). It was launched in 2011 and is currently in operation.

The National Polar-orbiting Operational Environmental Satellite System (NPOESS) was to be the United States' next-generation satellite system that would monitor the Earth's weather, atmosphere, oceans, land, and near-space environment. NPOESS satellites were to host proven technologies and operational versions of sensors that were under operational-prototyping by NASA, at that time. The estimated launch date for the first NPOESS satellite, "C1" or "Charlie 1" was around 2013. Issues with sensor developments were the primary cited reason for delays and cost-overruns.