The National Polar-Orbiting Operational Environmental Satellite System is called N P O E S S. tee hee.
http://www.realclimate.org/index.php/archives/2011/10/npp-lift-off/
We really need to apologise for the acronym soup though – it is an endemic disease in satellite discussions. Indeed, NPP is a recursive acronym, standing for N****S Preparatory Project, where N****S stands for the National Polar-Orbiting Operational Environmental Satellite System
http://www.realclimate.org/index.php/archives/2011/10/npp-lift-off/