Extending Science

NASA operates a large number of space science missions, approximately three-quarters of which are currently in their extended operations phase. They represent not only a majority of operational space science missions, but a substantial national investment and vital national assets. They are tremendously scientifically productive, making many of the major discoveries that are reported in the media and that rewrite textbooks. Extending Science ? NASA's Space Science Mission Extensions and the Senior Review Process evaluates the scientific benefits of missions extensions, the current process for extending missions, the current biennial requirement for senior reviews of mission extensions, the balance between starting new missions and extending operating missions, and potential innovative cost-reduction proposals for extended missions, and makes recommendations based on this review. Table of Contents Front Matter Summary 1 Introduction 2 The Scientific Benefits of Mission Extensions 3 Review of Extended Missions by NASA 4 The Balance of New Missions Versus Extended Missions 5 Innovative Cost Reductions for Extended Missions Appendixes Appendix A: Statement of Task Appendix B: Scientific Discoveries of the Lunar Reconnaissance Orbiter and Opportunity Rover During Extended Phase Appendix C: NASA Science Mission Directorate Budgets by Division for Fiscal Year 2016 Appendix D: Extended Mission and Senior Review References in Decadal Surveys Appendix E: Biographies of Committee Members and Staff Appendix F: Acronyms