International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The United States Government, through the Integrated Program Office (IPO), currently operates a converged polar orbiting constellation of POES and DMSP satellites to acquire, process and disseminate meteorological and environmental data on a global scale. Because of the increasing need for more precise and timely meteorological data, the IPO is developing the follow on system known as the National Polar-orbiting Operational Environmental Satellite System (NPOESS). The NPOESS system is expected to use a modernized, CCSDS compatible data acquisition and distribution network, and will provide more timely data than for the current POES/DMSP satellites. The NPOESS satellite system will also continue the collection of long-term environmental data as a follow on to NASA’s Earth Observation System (EOS). The continuation of NASA’s EOS system will begin with a risk reduction effort in support of NPOESS, known as the NPOESS Preparatory Project (NPP). This paper will describe the CCSDS implementation that both the NPP and NPOESS satellites are expected to use beginning with the launch of the NPP spacecraft in 2006. The launch of the first NPOESS satellite is anticipated in 2009.