The frontier represented by the near solar system confronts humanity with intriguing challenges and opportunities. With the inception of the Human Exploration and Development of Space (HEDS) enterprise in 1995, NASA has acknowledged the opportunities and has accepted the very significant challenges. Microgravity Research in Support of Technologies for the Human Exploration and Development of Space and Planetary Bodies was commissioned by NASA to assist it in coordinating the scientific information relevant to anticipating, identifying, and solving the technical problems that must be addressed throughout the HEDS program over the coming decades. This report assesses scientific and related technological issues facing NASA's Human Exploration and Development of Space endeavor, looking specifically at mission enabling and enhancing technologies which, for development, require an improved understanding of fluid and material behavior in a reduced gravity environment.

We live in a time of extraordinary discovery and progress in astronomy and astrophysics. The next decade will transform our understanding of the universe and humanity's place in it. Every decade the U.S. agencies that provide primary federal funding for astronomy and astrophysics request a survey to assess the status of, and opportunities for the Nation's efforts to forward our understanding of the cosmos. Pathways to Discovery in Astronomy and Astrophysics for the 2020s identifies the most compelling science goals and presents an ambitious program of ground- and space-based activities for future investment in the next decade and beyond. The decadal survey identifies three important science themes for the next decade aimed at investigating Earth-like extrasolar planets, the most energetic processes in the universe, and the evolution of galaxies. The Astro2020 report also recommends critical near-term actions to support the foundations of the profession as well as the technologies and tools needed to carry out the science. Table of Contents Front Matter Summary 1 Pathways to Discovery: From Foundations to Frontiers 2 A New Cosmic Perspective 3 The Profession and Its Societal Impacts: Gateways to Science, Pathways to Diversity, Equity, and Sustainability 4 Optimizing the Science: Foundations 5 Evaluating and Balancing the Operational Portfolio 6 Technology Foundations and Small and Medium Scale Sustaining Programs 7 Realizing the Opportunities: Medium- and Large-Scale Programs Appendixes Appendix A: Statement of Task and Panel Descriptions Appendix B: Report of the Panel on Compact Objects and Energetic Phenomena Appendix C: Report of the Panel on Cosmology Appendix D: Report of the Panel on Galaxies Appendix E: Report of the Panel on Exoplanets, Astrobiology, and the Solar System Appendix F: Report of the Panel on the Interstellar Medium and Star and Planet Formation Appendix G: Report of the Panel on Stars, the Sun, and Stellar Populations Appendix H: Report of the Panel on an Enabling Foundation for Research Appendix I: Report of the Panel on Electromagnetic Observations from Space 1 Appendix J: Report of the Panel on Electromagnetic Observations from Space 2 Appendix K: Report of the Panel on Optical and Infrared Observations from the Ground Appendix L: Report of the Panel on Particle Astrophysics and Gravitation Appendix M: Report of the Panel on Radio, Millimeter, and Submillimeter Observations from the Ground Appendix N: Report of the Panel on the State of the Profession and Societal Impacts Appendix O: Independent Technical, Risk, and Cost Evaluation Appendix P: Acronyms Appendix Q: Committee and Panel Biographical Information

The next decade of planetary science and astrobiology holds tremendous promise. New research will expand our understanding of our solar system's origins, how planets form and evolve, under what conditions life can survive, and where to find potentially habitable environments in our solar system and beyond. Origins, Worlds, and Life: A Decadal Strategy for Planetary Science and Astrobiology 2023-2032 highlights key science questions, identifies priority missions, and presents a comprehensive research strategy that includes both planetary defense and human exploration. This report also recommends ways to support the profession as well as the technologies and infrastructure needed to carry out the science. Table of Contents Front Matter Summary 1 Introduction to Planetary Science, Astrobiology, and Planetary Defense 2 Tour of the Solar System: A Transformative Decade of Exploration 3 Priority Science Questions 4 Question 1: Evolution of the Protoplanetary Disk 5 Question 2: Accretion in the Outer Solar System 6 Question 3: Origin of Earth and Inner Solar System Bodies 7 Question 4: Impacts and Dynamics 8 Question 5: Solid Body Interiors and Surfaces 9 Question 6: Solid Body Atmospheres, Exospheres, Magnetospheres, and Climate Evolution 10 Question 7: Giant Planet Structure and Evolution 11 Question 8: Circumplanetary Systems 12 Question 9: Insights from Terrestrial Life 13 Question 10: Dynamic Habitability 14 Question 11: Search for Life Elsewhere 15 Question 12: Exoplanets 16 State of the Profession 17 Research and Analysis 18 Planetary Defense: Defending Earth through Applied Planetary Science 19 Human Exploration 20 Infrastructure for Planetary Science and Exploration 21 Technology 22 Recommended Program: 2023-2032 23 The Future Appendixes Appendix A: Letter of Request, Statement of Task, and Other Guidance Appendix B: White Papers Received Appendix C: Technical Risk and Cost Evaluation of Priority Missions Appendix D: Missions Studied But Not Sent for TRACE Appendix E: Panel Missions Not Selected for Additional Study Appendix F: Glossary and Acronyms Appendix G: Biographies of Committee Members and Staff

In this new book, a distinguished panel makes recommendations for the nation's programs in astronomy and astrophysics, including a number of new initiatives for observing the universe. With the goal of optimum value, the recommendations address the role of federal research agencies, allocation of funding, training for scientists, competition and collaboration among space facilities, and much more. The book identifies the most pressing science questions and explains how specific efforts, from the Next Generation Space Telescope to theoretical studies, will help reveal the answers. Discussions of how emerging information technologies can help scientists make sense of the wealth of data available are also included. Astronomy has significant impact on science in general as well as on public imagination. The committee discusses how to integrate astronomical discoveries into our education system and our national life. In preparing the New Millennium report, the AASC made use of a series of panel reports that address various aspects of ground- and space-based astronomy and astrophysics. These reports provide in-depth technical detail. Astronomy and Astrophysics in the New Millenium: An Overview summarizes the science goals and recommended initiatives in a short, richly illustrated, non-technical booklet. Table of Contents Front Matter Executive Summary 1. Recommendations 2. The Science Behind the Recommendations 3. The New Initiatives: Building on the Current Program 4. Benefits to the Nation from Astronomy 5. The Role of Astronomy in Education 6. Policy for Astronomy and Astrophysics References Appendix: Definitions Index

Currently, the Departments of Defense (DOD) and Commerce (DOC) acquire and operate separate polarorbiting environmental satellite systems that collect data needed for military and civil weather forecasting. The National Performance Review (NPR) and subsequent Presidential Decision Directive (PDD), directed the DOD (Air Force) and the DOC (National Oceanic and Atmospheric Administration, NOAA) to establish a converged national weather satellite program that would meet U.S. civil and national security requirements and fulfill international obligations. NASA's Earth Observing System (EOS), and potentially other NASA programs, were included in the converged program to provide new remote sensing and spacecraft technologies that could improve the operational capabilities of the converged system. The program that followed, called the National Polar-orbiting Operational Environmental Satellite System (NPOESS), combined the follow-on to the DOD's Defense Meteorological Satellite Program and the DOC's Polar-orbiting Operational Environmental Satellite (POES) program. The tri-agency Integrated Program Office (IPO) for NPOESS was subsequently established to manage the acquisition and operations of the converged satellite. Issues in the Integration of Research and Operational Satellite Systems for Climate Research analyzes issues related to the integration of EOS and NPOESS, especially as they affect research and monitoring activities related to Earth's climate and whether it is changing.

New Worlds, New Horizons in Astronomy and Astrophysics (NWNH), the report of the 2010 decadal survey of astronomy and astrophysics, put forward a vision for a decade of transformative exploration at the frontiers of astrophysics. This vision included mapping the first stars and galaxies as they emerge from the collapse of dark matter and cold clumps of hydrogen, finding new worlds in a startlingly diverse population of extrasolar planets, and exploiting the vastness and extreme conditions of the universe to reveal new information about the fundamental laws of nature. NWNH outlined a compelling program for understanding the cosmic order and for opening new fields of inquiry through the discovery areas of gravitational waves, time-domain astronomy, and habitable planets. Many of these discoveries are likely to be enabled by cyber-discovery and the power of mathematics, physics, and imagination. To help realize this vision, NWNH recommended a suite of innovative and powerful facilities, along with balanced, strong support for the scientific community engaged in theory, data analysis, technology development, and measurements with existing and new instrumentation. Already in the first half of the decade, scientists and teams of scientists working with these cutting-edge instruments and with new capabilities in data collection and analysis have made spectacular discoveries that advance the NWNH vision. New Worlds, New Horizons: A Midterm Assessment reviews the responses of NASA's Astrophysics program, NSF's Astronomy program, and DOE's Cosmic Frontiers program to NWNH. This report describes the most significant scientific discoveries, technical advances, and relevant programmatic changes in astronomy and astrophysics over the years since the publication of the decadal survey, and assesses how well the Agencies' programs address the strategies, goals, and priorities outlined in the 2010 decadal survey. Table of Contents Front Matter Summary 1 Scientific Discoveries and Technical Advances 2 Programmatic Context 3 Progress Toward NWNH Goals - Ground-Based Program 4 Progress Toward NWNH Goals - Space-Based Program 5 The Next Decadal Survey of Astronomy and Astrophysics Appendixes Appendix A: Statement of Task Appendix B: Letter of Request Appendix C: Acronyms Appendix D: Biographies of Committee Members and Staff

On November 29-30, 2018, in Washington, D.C., the National Academies of Sciences, Engineering, and Medicine held the Workshop on the Continuous Improvement of NASA's Innovation Ecosystem. The workshop was requested by the National Aeronautics and Space Administration (NASA) Office of the Chief Technologist with the goal of identifying actionable and implementable initiatives that could build on NASA's current innovation culture to reach a future state that will ensure the agency's continued success in the evolving aerospace environment. This publication summarizes the presentations and discussions from the workshop. Table of Contents Front Matter 1 Introduction 2 Setting the Stage 3 What Should NASA's Future Look Like? 4 The Challenges 5 Strategies and Tactics for Creating the Desired Future 6 The Path Forward Appendixes Appendix A: Statement of Task Appendix B: Meeting Agendas Appendix C: Workshop Participant List Appendix D: Planning Committee, Rapporteur, and Staff Bios Appendix E: Acronyms

The NASA Science Mission Directorate/Earth Science Division's (SMD/ESD's) Earth Venture (EV) is a program element within the Earth System Science Pathfinder Program. At the request of NASA, this report examines the Earth Venture Instrument (EV-I) and Earth Venture Mission (EV-M) elements of Earth Ventures and explores lessons learned in the more than 10 years since selection of the first EV mission, including a review of the foundational principles and approaches underlying the program. Table of Contents Front Matter Summary 1 Introduction 2 EV-I and EV-M Experiences to Date 3 Changing Program Emphasis for Earth Venture Missions 4 Meeting the EV-I and EV-M Broader Objectives 5 Lessons Learned and Recommendations Appendixes Appendix A: Statement of Task Appendix B: Questions for Principal Investigators Appendix C: Committee Member Biographies Appendix D: Acronyms and Abbreviations

We live on a dynamic Earth shaped by both natural processes and the impacts of humans on their environment. It is in our collective interest to observe and understand our planet, and to predict future behavior to the extent possible, in order to effectively manage resources, successfully respond to threats from natural and human-induced environmental change, and capitalize on the opportunities ? social, economic, security, and more ? that such knowledge can bring. By continuously monitoring and exploring Earth, developing a deep understanding of its evolving behavior, and characterizing the processes that shape and reshape the environment in which we live, we not only advance knowledge and basic discovery about our planet, but we further develop the foundation upon which benefits to society are built. Thriving on Our Changing Planet presents prioritized science, applications, and observations, along with related strategic and programmatic guidance, to support the U.S. civil space Earth observation program over the coming decade. Table of Contents Front Matter PART I: Report of the Steering Committee Summary 1 A Vision for the Decade 2 A Decadal Strategy 3 A Prioritized Program for Science, Applications, and Observations 4 Agency Programmatic Context 5 Conclusion PART II: Panel Inputs 6 Global Hydrological Cycles and Water Resources 7 Weather and Air Quality: Minutes to Subseasonal 8 Marine and Terrestrial Ecosystems and Natural Resources Management 9 Climate Variability and Change: Seasonal to Centennial 10 Earth Surface and Interior: Dynamics and Hazards Appendixes Appendix A: Program of Record Appendix B: Science and Applications Traceability Matrix Appendix C: Targeted Observables Table Appendix D: Request for Information and Responses from the Community Appendix E: Statement of Task Appendix F: Committee Member and Panel Biographies Appendix G: Acronyms and Abbreviations

An international consensus policy to prevent the biological cross-contamination of planetary bodies exists and is maintained by the Committee on Space Research (COSPAR) of the International Council for Science, which is consultative to the United Nations Committee on the Peaceful Uses of Outer Space. Currently, COSPAR's planetary protection policy does not specify the status of sample-return missions from Phobos or Deimos, the moons of Mars. Although the moons themselves are not considered potential habitats for life or of intrinsic relevance to prebiotic chemical evolution, recent studies indicate that a significant amount of material recently ejected from Mars could be present on the surface of Phobos and, to a lesser extent, Deimos. This report reviews recent theoretical, experimental, and modeling research on the environments and physical conditions encountered by Mars ejecta during certain processes. It recommends whether missions returning samples from Phobos and/or Deimos should be classified as "restricted" or "unrestricted" Earth return in the framework of the planetary protection policy maintained by COSPAR. This report also considers the specific ways the classification of sample return from Deimos is a different case than sample return from Phobos. Table of Contents Front Matter Summary 1 Introduction 2 Overview and Assessment of the SterLim and JAXA Studies 3 Responses to the Statement of Task and Recommendations Appendixes Appendix A: Original Request from NASA Appendix B: Revised Request from NASA Appendix C: Committee Members and Staff Biographical Information

Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's.
Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity.
New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.

The search for life is one of the most active fields in space science and involves a wide variety of scientific disciplines, including planetary science, astronomy and astrophysics, chemistry, biology, chemistry, and geoscience. In December 2016, the Space Studies Board hosted a workshop to explore the possibility of habitable environments in the solar system and in exoplanets, techniques for detecting life, and the instrumentation used. This publication summarizes the presentations and discussions from the workshop. Table of Contents Front Matter 1 Setting the Stage 2 Habitable Environments in the Solar System 3 Exoplanets 4 Life Detection Techniques 5 Instrumentation 6 Future Directions: Report of Breakout Groups 7 Wrap-Up Appendixes Appendix A: Statement of Task Appendix B: Workshop Agenda Appendix C: Workshop Participants Appendix D: Poster Abstracts Appendix E: Biographies of Committee Members

In response to a request from the National Oceanic and Atmospheric Administration - and with the support of the National Aeronautics and Space Administration and the National Science Foundation - the National Academies of Sciences, Engineering, and Medicine conducted a two-part virtual workshop, "Space Weather Operations and Research Infrastructure," on June 16-17 and September 9-11, 2020. The overall goals of the workshop were to review present space weather monitoring and forecasting capabilities, to consider future observational infrastructure and research needs, and to consider options toward the further development of an effective, resilient, and achievable national space weather program. This publication summarizes the presentation and discussion of the workshop. Table of Contents Front Matter Summary 1 Introduction and Workshop Background 2 National Priorities and the Development of a National Strategy for Space Weather 3 U.S. Department and Agencies Roles and Current and Planned Capabilities 4 Complementary and Collaborative International Activities 5 Space Weather User Community Needs 6 Strategic Knowledge and Observation Gaps 7 Other Infrastructure Issues 8 Closing Observations Appendixes Appendix A: Statement of Task Appendix B: Poster Session at the November 9-11, 2020, Workshop Appendix C: Workshop Agendas Appendix D: Acronyms and Abbreviations Appendix E: Biographies of Committee Members and Staff

The goal of planetary protection is to control, to the degree possible, the biological cross-contamination of planetary bodies. Guidelines developed by the Committee on Space Research (COSPAR) are used by all spacefaring nations to guide their preparations for encounters with solar system bodies. NASA's Science Mission Directorate has convened the Planetary Protection Independent Review Board (PPIRB) to consider updating the COSPAR guidelines given the growing interest from commercial and private groups in exploration and utilization of Mars and other bodies in space. At the request of NASA, this publication reviews the findings of the PPIRB and comments on their consistency with the recommendations of the recent National Academies report Review and Assessment of the Planetary Protection Policy Development Processes. Table of Contents Front Matter Summary 1 Introduction 2 Assessment of the PPIRB's Findings and Recommendations 3 Conclusions and Recommendations Appendixes Appendix A: Letter Requesting this Study Appendix B: "Review and Assessment of Planetary Protection Policy Development Processes:" Findings and Recommendations Appendix C: Report of NASA's Planetary Protection Independent Review Board: Findings and Recommendations Appendix D: Establishment of the PPIRB Appendix E: Planetary Protection Categories Appendix F: Biographies of Committee Members and Staff

This study, commissioned by the National Aeronautics and Space Administration (NASA), examines the role of robotic exploration missions in assessing the risks to the first human missions to Mars. Only those hazards arising from exposure to environmental, chemical, and biological agents on the planet are assessed. To ensure that it was including all previously identified hazards in its study, the Committee on Precursor Measurements Necessary to Support Human Operations on the Surface of Mars referred to the most recent report from NASA's Mars Exploration Program/ Payload Analysis Group (MEPAG) (Greeley, 2001). The committee concluded that the requirements identified in the present NRC report are indeed the only ones essential for NASA to pursue in order to mitigate potential hazards to the first human missions to Mars.

Since its discovery in 1610, Europa-one of Jupiter's four large moons-has been an object of interest to astronomers and planetary scientists. Much of this interest stems from observations made by NASA's Voyager and Galileo spacecraft and from Earth-based telescopes indicating that Europa's surface is quite young, with very little evidence of cratering, and made principally of water ice. More recently, theoretical models of the jovian system and Europa have suggested that tidal heating may have resulted in the existence of liquid water, and perhaps an ocean, beneath Europa's surface. NASA's ongoing Galileo mission has profoundly expanded our understanding of Europa and the dynamics of the jovian system, and may allow us to constrain theoretical models of Europa's subsurface structure. Meanwhile, since the time of the Voyagers, there has been a revolution in our understanding of the limits of life on Earth. Life has been detected thriving in environments previously thought to be untenable-around hydrothermal vent systems on the seafloor, deep underground in basaltic rocks, and within polar ice. Elsewhere in the solar system, including on Europa, environments thought to be compatible with life as we know it on Earth are now considered possible, or even probable. Spacecraft missions are being planned that may be capable of proving their existence. Against this background, the Space Studies Board charged its Committee on Planetary and Lunar Exploration (COMPLEX) to perform a comprehensive study to assess current knowledge about Europa, outline a strategy for future spacecraft missions to Europa, and identify opportunities for complementary Earth-based studies of Europa. (See the preface for a full statement of the charge.) Table of Contents Front Matter Contents Executive Summary 1 Why Europa? 2 Current State of Knowledge About Europa 3 Strategy for the Post-Galileo Exploration of Europa 4 Earth-based Studies and Technology Development 5 Related Issues 6 Conclusions and Recommendations

The 2013 report Solar and Space Physics; A Science for a Technological Society outlined a program of basic and applied research for the period 2013-2022. This publication describes the most significant scientific discoveries, technical advances, and relevant programmatic changes in solar and space physics since the publication of that decadal survey. Progress Toward Implementation of the 2013 Decadal Survey for Solar and Space Physics assesses the degree to which the programs of the National Science Foundation and the National Aeronautics and Space Administration address the strategies, goals, and priorities outlined in the 2013 decadal survey, and the progress that has been made in meeting those goals. This report additionally considers steps to enhance career opportunities in solar and space physics and recommends actions that should be undertaken to prepare for the next decadal survey. Table of Contents Front Matter Summary 1 Introduction to Heliophysics and the 2013 Decadal Survey 2 Science Discoveries and Technical Advances 3 Progress, Opportunities, and Challenges for Decadal Survey Research Goals and Recommendations 4 Progress, Opportunities, and Challenges for Decadal Survey Applications Goals and Recommendations 5 Heliophysics Career Enhancements 6 Preparing for the Next Heliophysics Decadal Survey Appendixes Appendix A: Statement of Task Appendix B: Biographies of Committee Members and Staff Appendix C: Committee Meeting Agendas Appendix D: Report Findings Appendix E: Progress for Science Challenges in 2013 Heliophysics Decadal Survey Appendix F: Acronyms

Modern science is ever more driven by computations and simulations. In particular, the state of the art in space and Earth science often arises from complex simulations of climate, space weather, and astronomical phenomena. At the same time, scientific work requires data processing, presentation, and analysis through broadly available proprietary and community software.1 Implicitly or explicitly, software is central to science. Scientific discovery, understanding, validation, and interpretation are all enhanced by access to the source code of the software used by scientists. This report investigates and recommends options for NASA's Science Mission Directorate (SMD) as it considers how to establish a policy regarding open source software to complement its existing policy on open data. In particular, the report reviews existing data and software policies and the lessons learned from the implementation of those policies, summarizes community perspectives, and presents policy options and recommendations for implementing an open source software policy for NASA SMD. Table of Contents Front Matter Summary 1 Introduction and Policy Purpose 2 Background Materials 3 Past and Current Policies 4 Lessons Learned from Community Perspectives 5 Policy Options and Recommendations 6 Discussion Appendixes Appendix A: Statement of Task Appendix B: Copyright Issues of Interest to NASA Investigators and Developers of Software Appendix C: Call for White Papers and Listing of Received White Papers Appendix D: Biographies of Committee Members and Staff Appendix E: Acronyms

In spring 2011 the National Academies of Sciences, Engineering, and Medicine produced a report outlining the next decade in planetary sciences. That report, titled Vision and Voyages for Planetary Science in the Decade 2013-2022, and popularly referred to as the "decadal survey," has provided high-level prioritization and guidance for NASA's Planetary Science Division. Other considerations, such as budget realities, congressional language in authorization and appropriations bills, administration requirements, and cross-division and cross-directorate requirements (notably in retiring risk or providing needed information for the human program) are also necessary inputs to how NASA develops its planetary science program. In 2016 NASA asked the National Academies to undertake a study assessing NASA's progress at meeting the objectives of the decadal survey. After the study was underway, Congress passed the National Aeronautics and Space Administration Transition Authorization Act of 2017 which called for NASA to engage the National Academies in a review of NASA's Mars Exploration Program. NASA and the Academies agreed to incorporate that review into the midterm study. That study has produced this report, which serves as a midterm assessment and provides guidance on achieving the goals in the remaining years covered by the decadal survey as well as preparing for the next decadal survey, currently scheduled to begin in 2020. Table of Contents Front Matter Summary 1 Background on the Decadal Survey and Midterm Assessment 2 Recent Scientific Discoveries 3 Assessment of Current Progress vis--vis Vision and Voyages and Guidance for the Rest of the Decade 4 Planetary Science Technology 5 Mars Exploration Architecture 6 Preparing for the Next Decadal Survey Appendixes Appendix A: Statement of Task Appendix B: Committee Biographical Information Appendix C: Acronyms

NASA's Science Mission Directorate (SMD) currently operates over five dozen missions, with approximately two dozen additional missions in development. These missions span the scientific fields associated with SMD's four divisions?Astrophysics, Earth Science, Heliophysics, and Planetary Sciences. Because a single mission can consist of multiple spacecraft, NASA-SMD is responsible for nearly 100 operational spacecraft. The most high profile of these are the large strategic missions, often referred to as "flagships." Large strategic missions are essential to maintaining the global leadership of the United States in space exploration and in science because only the United States has the budget, technology, and trained personnel in multiple scientific fields to conduct missions that attract a range of international partners. This report examines the role of large, strategic missions within a balanced program across NASA-SMD space and Earth sciences programs. It considers the role and scientific productivity of such missions in advancing science, technology and the long-term health of the field, and provides guidance that NASA can use to help set the priority of larger missions within a properly balanced program containing a range of mission classes. Table of Contents Front Matter Summary 1 Introduction 2 Balancing Strategic Missions 3 Risks and Realities of Cost Overruns for Large Strategic Missions 4 Comparing Large Strategic Missions and Smaller Missions Appendixes Appendix A: Statement of Task Appendix B: Astrophysics Science Division Missions Appendix C: Earth Science Division Missions Appendix D: Heliophysics Science Division Missions Appendix E: Planetary Science Division Missions Appendix F: Biographies of Committee Members and Staff Appendix G: Acronyms

Affecting technological systems at a global-scale, space weather can disrupt high-frequency radio signals, satellite-based communications, navigational satellite positioning and timing signals, spacecraft operations, and electric power delivery with cascading socioeconomic effects resulting from these disruptions. Space weather can also present an increased health risk for astronauts, as well as aviation flight crews and passengers on transpolar flights. In 2019, the National Academies was approached by the National Aeronautics and Space Administration, the National Oceanic and Atmospheric Administration, and the National Science Foundation to organize a workshop that would examine the operational and research infrastructure that supports the space weather enterprise, including an analysis of existing and potential future measurement gaps and opportunities for future enhancements. This request was subsequently modified to include two workshops, the first ("Phase I") of which occurred in two parts on June 16-17 and September 9-11, 2020. The Phase II workshop occurred on April 11-14, 2022, with sessions on agency updates, research needs, data science, observational and modeling needs, and emerging architectures relevant to the space weather research community and with ties to operational needs. This publication summarizes the presentation and discussion of that workshop. Table of Contents Front Matter Summary 1 The Space Weather Community 2 Research, Observation, and Modeling Needs: The Sun and Heliosphere 3 Research, Observation, and Modeling Needs: Magnetosphere, Ionosphere, Thermosphere, and Mesosphere 4 Research, Observation, and Modeling Needs: Ground Effects 5 Modeling, Validation, and Data Science 6 Research Infrastructure Appendixes Appendix A: Statement of Task Appendix B: Workshop Agenda Appendix C: Poster Session at the April 1114, 2022, Workshop Appendix D: Acronyms and Abbreviations Appendix E: Biographies of Committee Members and Staff

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

Space-based observations have transformed our understanding of Earth, its environment, the solar system and the universe at large. During past decades, driven by increasingly advanced science questions, space observatories have become more sophisticated and more complex, with costs often growing to billions of dollars. Although these kinds of ever-more-sophisticated missions will continue into the future, small satellites, ranging in mass between 500 kg to 0.1 kg, are gaining momentum as an additional means to address targeted science questions in a rapid, and possibly more affordable, manner. Within the category of small satellites, CubeSats have emerged as a space-platform defined in terms of (10 cm x 10 cm x 10 cm)- sized cubic units of approximately 1.3 kg each called "U's." Historically, CubeSats were developed as training projects to expose students to the challenges of real-world engineering practices and system design. Yet, their use has rapidly spread within academia, industry, and government agencies both nationally and internationally. In particular, CubeSats have caught the attention of parts of the U.S. space science community, which sees this platform, despite its inherent constraints, as a way to affordably access space and perform unique measurements of scientific value. The first science results from such CubeSats have only recently become available; however, questions remain regarding the scientific potential and technological promise of CubeSats in the future. Achieving Science with CubeSats reviews the current state of the scientific potential and technological promise of CubeSats. This report focuses on the platform's promise to obtain high- priority science data, as defined in recent decadal surveys in astronomy and astrophysics, Earth science and applications from space, planetary science, and solar and space physics (heliophysics); the science priorities identified in the 2014 NASA Science Plan; and the potential for CubeSats to advance biology and microgravity research. It provides a list of sample science goals for CubeSats, many of which address targeted science, often in coordination with other spacecraft, or use "sacrificial," or high-risk, orbits that lead to the demise of the satellite after critical data have been collected. Other goals relate to the use of CubeSats as constellations or swarms deploying tens to hundreds of CubeSats that function as one distributed array of measurements. Table of Contents Front Matter Summary 1 Introduction 2 CubeSats - A Disruptive Innovation 3 CubeSats as a Tool for Education and Hands-on Training 4 Science Impact and Potential 5 Technology Development: Current Status and Future Direction 6 Policy Challenges and Solutions 7 Conclusions and Future Program Recommendations Appendixes Appendix A: Statement of Task Appendix B: CubeSat Publications - Descriptive Statistics Appendix C: Additional Technology and Policy Details Appendix D: Biographies of Committee Members and Staff Appendix E: Abbreviations and Acronyms

In January 2004 NASA was given a new policy direction known as the Vision for Space Exploration. That plan, now renamed the United States Space Exploration Policy, called for sending human and robotic missions to the Moon, Mars, and beyond. In 2005 NASA outlined how to conduct the first steps in implementing this policy and began the development of a new human-carrying spacecraft known as Orion, the lunar lander known as Altair, and the launch vehicles Ares I and Ares V. Collectively, these are called the Constellation System. In November 2007 NASA asked the National Research Council (NRC) to evaluate the potential for new science opportunities enabled by the Constellation System of rockets and spacecraft. The NRC committee evaluated a total of 17 mission concepts for future space science missions. Of those, the committee determined that 12 would benefit from the Constellation System and five would not. This book presents the committee's findings and recommendations, including cost estimates, a review of the technical feasibility of each mission, and identification of the missions most deserving of future study.

The National Research Council has conducted 11 decadal surveys in the Earth and space sciences since 1964 and released the latest four surveys in the past 8 years. The decadal surveys are notable in their ability to sample thoroughly the research interest, aspirations, and needs of a scientific community. Through a rigorous process, a primary survey committee and thematic panels of community members construct a prioritized program of science goals and objectives and define an executable strategy for achieving them. These reports play a critical role in defining the nation's agenda in that science area for the following 10 years, and often beyond. The Space Science Decadal Surveys considers the lessons learned from previous surveys and presents options for possible changes and improvements to the process, including the statement of task, advanced preparation, organization, and execution. This report discusses valuable aspects of decadal surveys that could taken further, as well as some challenges future surveys are likely to face in searching for the richest areas of scientific endeavor, seeking community consensus of where to go next, and planning how to get there. The Space Science Decadal Surveys describes aspects in the decadal survey prioritization process, including balance in the science program and across the discipline; balance between the needs of current researchers and the development of the future workforce; and balance in mission scale - smaller, competed programs versus large strategic missions. Table of Contents Front Matter Summary 1 Decadal Surveys: Community Consensus in Science Priorities 2 The Decadal Survey Process 3 The Decadal Survey's Recommended Program 4 Implementing the Decadal Survey Appendixes Appendix A: NASA Strategic Goals and Objectives Appendix B:Implementing the CATE Process Appendix C: Letter Requesting This Study Appendix D: Lessons Learned and Best Practices for Decadal Surveys Appendix E: Committee and Staff Biographies Appendix F: Acronyms and Abbreviations