Extending the Effective Lifetimes of Earth Observing Research Missions

While NASA Earth Science missions are planned on the basis of a specified lifetime, often they are able to function beyond the end of that period. Until recently NASA had no formal mechanism for determining whether those missions should be extended or whether the resources necessary for the extension should be applied to new missions. In August 2004, when NASA merged Earth and space sciences, the agency began using the Science Review process to make those extension determinations. NASA had asked the NRC to assess extension review processes, and after the merger, this study focused on the Science Review process. This report presents an assessment of that process and provides recommendations for adapting it to Earth Science missions.