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 ContentsFront MatterSummary1 Introduction2 The Scientific Benefits of Mission Extensions3 Review of Extended Missions by NASA4 The Balance of New Missions Versus Extended Missions5 Innovative Cost Reductions for Extended MissionsAppendixesAppendix A: Statement of TaskAppendix B: Scientific Discoveries of the Lunar ReconnaissanceOrbiter and Opportunity Rover During Extended PhaseAppendix C: NASA Science Mission Directorate Budgets by Divisionfor Fiscal Year 2016Appendix D: Extended Mission and Senior Review References inDecadal SurveysAppendix E: Biographies of Committee Members and StaffAppendix F: Acronyms