Book excerpt: The Nat. Polar-orbiting Operational Environmental Satellite System (NPOESS) is a tri-agency acquisition -- managed by the NOAA, DoD, and NASA -- that has experienced escalating costs, schedule delays, and technical difficulties. These factors led to a June 2006 decision to restructure the program by reducing the number of satellites and sensors, increasing estimated costs to $12.5 billion, and delaying the first two satellites by 3-5 years. This report evaluates progress in restructuring the acquisition, assesses the status of key program components and risks, and assesses NASA¿s, NOAA¿s, and DoD¿s plans for obtaining the data originally planned to be collected by NPOESS sensors, but eliminated by the restructuring. Includes recommend. Tables.