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

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

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

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

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

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

This report is the summary of a workshop held in May 2003 by the Space Studies Board's Committee on Solar and Space Physics to synthesize understanding of the physics of the outer heliosphere and the critical role played by the local interstellar medium (LISM) and to identify directions for the further exploration of this challenging environment.

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.

Satellite Observations to Benefit Science and Society: Recommended Missions for the Next Decade brings the next ten years into focus for the Earth and environmental science community with a prioritized agenda of space programs, missions, and supporting activities that will best serve scientists in the next decade. These missions will address a broad range of societal needs, such as more reliable weather forecasts, early earthquake warnings, and improved pollution management, benefiting both scientific discovery and the health and well-being of society. Based on the 2007 book, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, this book explores each of the seventeen recommended missions in detail, identifying launch dates, responsible agencies, estimated cost, scientific and public benefits, and more. Printed entirely in color, the book features rich photographs and illustrations, tables, and graphs that will keep the attention of scientists and non-scientists alike. Table of Contents Front Matter An Integrated Strategy: Satellite Observations to Benefit Science and Society Selecting and Prioritizing the Missions Recommended Missions ACE, Aerosol-Cloud-Ecosystems ASCENDS, Active Sensing of CO2 Emissions over Nights, Days, and Seasons CLARREO, Climate Absolute Radiance and Refractivity Observatory DESDynI, Deformation, Ecosystem Structure, and Dynamics of Ice GACM, Global Atmospheric Composition Mission GEO-CAPE, Geostationary Coastal and Air Pollution Events GPSRO, Operational GPSRadio Occultation GRACE-II, Gravity Recovery and Climate Experiment II HyspIRI, Hyperspectral Infrared Imager ICESat-II, Ice, Cloud, and Land Elevation Satellite II LIST, Lidar Surface Topography PATH, Precipitation and All-Weather Temperature and Humidity SCLP, Snow and Cold Land Processes SMAP, Soil Moisture Active-Passive SWOT, Surface Water and Ocean Topography 3D-Winds, Three-Dimensional Tropospheric Winds XOVWM, Extended Ocean Vector Winds Mission From Satellite Observations to Earth Information

The National Aeronautics and Space Administration (NASA) and other U.S. science research agencies operate a fleet of research aircraft and other airborne platforms that offer diverse capabilities. To inform NASA's future investments in airborne platforms, this study examines whether a large aircraft that would replace the current NASA DC-8 is needed to address Earth system science questions, and the role of other airborne platforms for achieving future Earth system science research goals. Table of Contents Front Matter Summary 1 Introduction 2 Setting the Stage: The Role of Airborne Platforms in Earth System Science 3 The DC-8 Airborne Research Platform 4 The Role of Airborne Platforms in Addressing Emerging Science 5 Workforce Training and Development 6 Recommendations for the Future Need of a Large Aircraft References Appendix A: Committee Member Biographies Appendix B: Statement of Task Appendix C: Acronyms Appendix D: 2017 Earth Science and Applications from Space Decadal Survey Table 3.2 Appendix E: Atmospheric Chemistry Detailed Measurements

Every 10 years the National Research Council releases a survey of astronomy and astrophysics outlining priorities for the coming decade. The most recent survey, titled New Worlds, New Horizons in Astronomy and Astrophysics, provides overall priorities and recommendations for the field as a whole based on a broad and comprehensive examination of scientific opportunities, infrastructure, and organization in a national and international context. Panel Reports?New Worlds, New Horizons in Astronomy and Astrophysics is a collection of reports, each of which addresses a key sub-area of the field, prepared by specialists in that subarea, and each of which played an important role in setting overall priorities for the field. The collection, published in a single volume, includes the reports of the following panels: Cosmology and Fundamental Physics Galaxies Across Cosmic Time The Galactic Neighborhood Stars and Stellar Evolution Planetary Systems and Star Formation Electromagnetic Observations from Space Optical and Infrared Astronomy from the Ground Particle Astrophysics and Gravitation Radio, Millimeter, and Submillimeter Astronomy from the Ground The Committee for a Decadal Survey of Astronomy and Astrophysics synthesized these reports in the preparation of its prioritized recommendations for the field as a whole. These reports provide additional depth and detail in each of their respective areas. Taken together, they form an essential companion volume to New Worlds, New Horizons: A Decadal Survey of Astronomy and Astrophysics. The book of panel reports will be useful to managers of programs of research in the field of astronomy and astrophysics, the Congressional committees with jurisdiction over the agencies supporting this research, the scientific community, and the public. Table of Contents Front Matter Part I: Reports of the Astro2010 Science Frontiers Panels 1 Report of the Panel on Cosmology and Fundamental Physics 2 Report of the Panel on the Galactic Neighborhood 3 Report of the Panel on Galaxies Across Cosmic Time 4 Report of the Panel on Planetary Systems and Star Formation 5 Report of the Panel on Stars and Stellar Evolution Summary Findings Part II: Reports of the Astro2010 Program Prioritization Panels 6 Report of the Panel on Electromagnetic Observations from Space 7 Report of the Panel on Optical and Infrared Astronomy from the Ground 8 Report of the Panel on Particle Astrophysics and Gravitation 9 Report of the Panel on Radio, Millimeter, and Submillimeter Astronomy from the Ground Appendixes Appendix A: Statements of Task for the Astro2010 Panels Appendix B: Glossary Appendix C Acronyms

NASA's Earth Science Division (ESD) conducts a wide range of satellite and suborbital missions to observe Earth's land surface and interior, biosphere, atmosphere, cryosphere, and oceans as part of a program to improve understanding of Earth as an integrated system. Earth observations provide the foundation for critical scientific advances and environmental data products derived from these observations are used in resource management and for an extraordinary range of societal applications including weather forecasts, climate projections, sea level change, water management, disease early warning, agricultural production, and the response to natural disasters. As the complexity of societal infrastructure and its vulnerability to environmental disruption increases, the demands for deeper scientific insights and more actionable information continue to rise. To serve these demands, NASA's ESD is challenged with optimizing the partitioning of its finite resources among measurements intended for exploring new science frontiers, carefully characterizing long-term changes in the Earth system, and supporting ongoing societal applications. This challenge is most acute in the decisions the Division makes between supporting measurement continuity of data streams that are critical components of Earth science research programs and the development of new measurement capabilities. This report seeks to establish a more quantitative understanding of the need for measurement continuity and the consequences of measurement gaps. Continuity of NASA's Earth's Observations presents a framework to assist NASA's ESD in their determinations of when a measurement or dataset should be collected for durations longer than the typical lifetimes of single satellite missions. Table of Contents Front Matter Summary 1 Introduction 2 Measurement Continuity 3 A Decision Framework for NASA Earth Science Continuity Measurements 4 Applying the Framework to Continuity Measurements Appendixes Appendix A: Statement of Task Appendix B: Quality Metric Examples Using Current Climate Data Records Appendix C: Full Framework Example: Narrowing Uncertainty in Climate Sensitivity Appendix D: Full Framework Example: Determining Sea Level Rise and Its Acceleration Appendix E: Full Framework Example: Determining the Change in Ocean Heat Storage Appendix F: Full Framework Example: Determining Ice Sheet Mass Balance Appendix G: Full Framework Example: Global Land Carbon Sinks Appendix H: Committee and Staff Biographical Information Appendix I: Acronyms and Abbreviations

The National Research Council (NRC) has been conducting decadal surveys in the Earth and space sciences since 1964, and released the latest five surveys in the past 5 years, four of which were only completed in the past 3 years. Lessons Learned in Decadal Planning in Space Science is the summary of a workshop held in response to unforseen challenges that arose in the implementation of the recommendations of the decadal surveys. This report takes a closer look at the decadal survey process and how to improve this essential tool for strategic planning in the Earth and space sciences. Workshop moderators, panelists, and participants lifted up the hood on the decadal survey process and scrutinized every element of the decadal surveys to determine what lessons can be gleaned from recent experiences and applied to the design and execution of future decadal surveys. Table of Contents Front Matter 1 Summary of Keynote Speakers Remarks 2 Overview of the Decadal Survey Process 3 Decadal Survey Chairs' Perspective 4 Sponsor Agency Perspectives 5 Decadal Survey Program Formulation and Opportunities for Improvement 6 The Role of Cost Estimates, Technical Evaluations, and Budget Projections in Prioritizing Missions 7 How to Plan for High-Profile Missions 8 Incorporating International Perspectives in Future Decadal Planning 9 Decadal Survey Stewardship: The Role of the Mid-Decade Reviews and Standing Committees 10 Concluding Remarks Appendixes Appendix A: Workshop Agenda Appendix B: Biographies of Planning Committee Members, Moderators, Panelists, and Staff

More than four decades have passed since a human first set foot on the Moon. Great strides have been made in our understanding of what is required to support an enduring human presence in space, as evidenced by progressively more advanced orbiting human outposts, culminating in the current International Space Station (ISS). However, of the more than 500 humans who have so far ventured into space, most have gone only as far as near-Earth orbit, and none have traveled beyond the orbit of the Moon. Achieving humans' further progress into the solar system had proved far more difficult than imagined in the heady days of the Apollo missions, but the potential rewards remain substantial. During its more than 50-year history, NASA's success in human space exploration has depended on the agency's ability to effectively address a wide range of biomedical, engineering, physical science, and related obstacles-an achievement made possible by NASA's strong and productive commitments to life and physical sciences research for human space exploration, and by its use of human space exploration infrastructures for scientific discovery. The Committee for the Decadal Survey of Biological and Physical Sciences acknowledges the many achievements of NASA, which are all the more remarkable given budgetary challenges and changing directions within the agency. In the past decade, however, a consequence of those challenges has been a life and physical sciences research program that was dramatically reduced in both scale and scope, with the result that the agency is poorly positioned to take full advantage of the scientific opportunities offered by the now fully equipped and staffed ISS laboratory, or to effectively pursue the scientific research needed to support the development of advanced human exploration capabilities. Although its review has left it deeply concerned about the current state of NASA's life and physical sciences research, the Committee for the Decadal Survey on Biological and Physical Sciences in Space is nevertheless convinced that a focused science and engineering program can achieve successes that will bring the space community, the U.S. public, and policymakers to an understanding that we are ready for the next significant phase of human space exploration. The goal of this report is to lay out steps and develop a forward-looking portfolio of research that will provide the basis for recapturing the excitement and value of human spaceflight-thereby enabling the U.S. space program to deliver on new exploration initiatives that serve the nation, excite the public, and place the United States again at the forefront of space exploration for the global good. Table of Contents Front Matter Summary 1 Introduction 2 Review of NASA's Program Evolution in the Life and Physical Sciences in Low-Gravity and Microgravity Environments 3 Conducting Microgravity Research: U.S. and International Facilities 4 Plant and Microbial Biology 5 Behavior and Mental Health 6 Animal and Human Biology 7 Crosscutting Issues for Humans in the Space Environment 8 Fundamental Physical Sciences in Space 9 Applied Physical Sciences 10 Translation to Space Exploration Systems 11 The Role of the International Space Station 12 Establishing a Life and Physical Sciences Research Program: Programmatic Issues 13 Establishing a Life and Physical Sciences Research Program: An Integrated Microgravity Research Portfolio Appendixes Appendix A: Statement of Task Appendix B: Glossary and Selected Acronyms Appendix C: Committee, Panel, and Staff Biographical Information

The New Frontiers Program was created by NASA in 2002 at the recommendation of the NRC's decadal survey for solar system research. In order to optimize solar system research, the NRC recommended a series of principal-investigator missions that encourage innovation and accomplish the main scientific objectives presented in the survey. Two of the five recommended missions have been selected and, as was also recommended in the survey, the NRC was asked in 2007 to provide criteria and guiding principles to NASA for determining the list of candidate missions. This book presents a review of eight missions: the three remaining from the original list of five from the survey plus five missions considered by the survey committee but which were not recommended. Included in the review of each mission is a discussion of relevant science and technology developments since the survey and set of recommended science goals.

A workshop to assess the science and technology of life detection techniques was organized by the Committee on the Origins and Evolution of Life (COEL) of the Board on Life Sciences (BLS) and the Space Studies Board (SSB). Topics discussed in the workshop included the search for extraterrestrial life in situ and in the laboratory, extant life and the signature of extinct life, and determination of the point of origin (terrestrial or not) of detected organisms. Table of Contents Front Matter Executive Summary 1 Detection of Life 2 Sample Return 3 Detecting Extant Life 4 Detecting Extinct Life 5 Conclusions and Recommendations Appendix A Glossary and Acronyms Appendix B Workshop Agenda Appendix C Workshop Papers Workshop Papers Session 1: Introduction to the Detection of Life Workshop Papers Session 2: Sample Return Workshop Papers Session 3: Detecting Extant Life Workshop Papers Session 4: Detecting Extinct Life

NASA's long-range plans include possible human exploratory missions to the moon and Mars within the next quarter century. Such missions beyond low Earth orbit will expose crews to transient radiation from solar particle events as well as continuous high-energy galactic cosmic rays ranging from energetic protons with low mean linear energy transfer (LET) to nuclei with high atomic numbers, high energies, and high LET. Because the radiation levels in space are high and the missions long, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. The knowledge base needed to design shielding involves two sets of factors, each with quantitative uncertainty-the radiation spectra and doses present behind different types of shielding, and the effects of the doses on relevant biological systems. It is only prudent to design shielding that will protect the crew of spacecraft exposed to predicted high, but uncertain, levels of radiation and biological effects. Because of the uncertainties regarding the degree and type of radiation protection needed, a requirement for shielding to protect against large deleterious, but uncertain, biological effects may be imposed, which in turn could result in an unacceptable cost to a mission. It therefore is of interest to reduce these uncertainties in biological effects and shielding requirements for reasons of mission feasibility, safety, and cost.

In 1972 NASA launched the Earth Resources Technology Satellite (ETRS), now known as Landsat 1, and on February 11, 2013 launched Landsat 8. Currently the United States has collected 40 continuous years of satellite records of land remote sensing data from satellites similar to these. Even though this data is valuable to improving many different aspects of the country such as agriculture, homeland security, and disaster mitigation; the availability of this data for planning our nation\'s future is at risk. Thus, the Department of the Interior\'s (DOI\'s) U.S. Geological Survey (USGS) requested that the National Research Council\'s (NRC\'s) Committee on Implementation of a Sustained Land Imaging Program review the needs and opportunities necessary for the development of a national space-based operational land imaging capability. The committee was specifically tasked with several objectives including identifying stakeholders and their data needs and providing recommendations to facilitate the transition from NASA\'s research-based series of satellites to a sustained USGS land imaging program. Landsat and Beyond: Sustaining and Enhancing the Nation's Land Imaging Program is the result of the committee\'s investigation. This investigation included meetings with stakeholders such as the DOI, NASA, NOAA, and commercial data providers. The report includes the committee\'s recommendations, information about different aspects of the program, and a section dedicated to future opportunities. Table of Contents Front Matter Summary 1 Imperative for a Sustained and Enhanced Land Imaging Program 2 Technical Characteristics of the Core Program 3 Enhancing a Sustained Land Imaging Program 4 Data Systems 5 Opportunities on the Path Forward Appendixes Appendix A: Statement of Task Appendix B: Acronyms Appendix C: Committee and Staff Biographical Information Cover Credits

Great advances have been made in our understanding of the climate system over the past few decades, and remotely sensed data have played a key role in supporting many of these advances. Improvements in satellites and in computational and data-handling techniques have yielded high quality, readily accessible data. However, rapid increases in data volume have also led to large and complex datasets that pose significant challenges in data analysis. Uncertainty characterization is needed for every satellite mission and scientists continue to be challenged by the need to reduce the uncertainty in remotely sensed climate records and projections. The approaches currently used to quantify the uncertainty in remotely sensed data lack an overall mathematically based framework. An additional challenge is characterizing uncertainty in ways that are useful to a broad spectrum of end-users. In December 2008, the National Academies held a workshop, summarized in this volume, to survey how statisticians, climate scientists, and remote sensing experts might address the challenges of uncertainty management in remote sensing of climate data. The workshop emphasized raising and discussing issues that could be studied more intently by individual researchers or teams of researchers, and setting the stage for possible future collaborative activities. Table of Contents Front Matter 1 Introduction 2 Cross-Cutting Issues 3 Concluding Thoughts References Appendix A: Workshop Agenda Appendix B: Summaries of Workshop Presentations Appendix C: Planning Committee andRapporteur Biographies

Spacecraft require electrical energy. This energy must be available in the outer reaches of the solar system where sunlight is very faint. It must be available through lunar nights that last for 14 days, through long periods of dark and cold at the higher latitudes on Mars, and in high-radiation fields such as those around Jupiter. Radioisotope power systems (RPSs) are the only available power source that can operate unconstrained in these environments for the long periods of time needed to accomplish many missions, and plutonium-238 (238Pu) is the only practical isotope for fueling them.
Plutonium-238 does not occur in nature. The committee does not believe that there is any additional 238Pu (or any operational 238Pu production facilities) available anywhere in the world.The total amount of 238Pu available for NASA is fixed, and essentially all of it is already dedicated to support several pending missions--the Mars Science Laboratory, Discovery 12, the Outer Planets Flagship 1 (OPF 1), and (perhaps) a small number of additional missions with a very small demand for 238Pu. If the status quo persists, the United States will not be able to provide RPSs for any subsequent missions.

Because of the Moon's unique place in the evolution of rocky worlds, it is a prime focus of NASA's space exploration vision. Currently NASA is defining and implementing a series of robotic orbital and landed missions to the Moon as the initial phase of this vision. To realize the benefits of this activity, NASA needs a comprehensive, well-validated, and prioritized set of scientific research objectives. To help establish those objectives, NASA asked the NRC to provide guidance on the scientific challenges and opportunities enabled by sustained robotic and human exploration of the Moon during the period 2008-2023 and beyond. This final report presents a review of the current understanding of the early earth and moon; the identification of key science concepts and goals for moon exploration; an assessment of implementation options; and a set of prioritized lunar science concepts, goals, and recommendations. An interim report was released in September 2006. Table of Contents Front Matter Executive Summary 1 Introduction 2 Current Understanding of Early Earth and the Moon 3 Science Concepts and Goals 4 Implementation 5 Prioritized Lunar Science Concepts, Goals, and Recommendations 6 Observations and Science Potentially Enabled by the Vision for Space 7 Concepts Related to the Implementation of Science 8 Concluding Remarks Bibliography Appendix A Statement of Task Appendix B Glossary, Acronyms, and Abbreviations Appendix C Public Agendas for Meetings Appendix D Lunar Beijing Declaration Appendix E Committee Outreach Activities Appendix F Biographies of Committee Members and Staff

The sun is the source of energy for life on earth and is the strongest modulator of the human physical environment. In fact, the Suna (TM)s influence extends throughout the solar system, both through photons, which provide heat, light, and ionization, and through the continuous outflow of a magnetized, supersonic ionized gas known as the solar wind. While the accomplishments of the past decade have answered important questions about the physics of the Sun, the interplanetary medium, and the space environments of Earth and other solar system bodies, they have also highlighted other questions, some of which are long-standing and fundamental. The Sun to the Eartha "and Beyond organizes these questions in terms of five challenges that are expected to be the focus of scientific investigations in solar and space physics during the coming decade and beyond.

The United States has publicly funded its human spaceflight program on a continuous basis for more than a half-century, through three wars and a half-dozen recessions, from the early Mercury and Gemini suborbital and Earth orbital missions, to the lunar landings, and thence to the first reusable winged crewed spaceplane that the United States operated for three decades. Today the United States is the major partner in a massive orbital facility - the International Space Station - that is becoming the focal point for the first tentative steps in commercial cargo and crewed orbital space flights. And yet, the long-term future of human spaceflight beyond this project is unclear. Pronouncements by multiple presidents of bold new ventures by Americans to the Moon, to Mars, and to an asteroid in its native orbit, have not been matched by the same commitment that accompanied President Kennedy\'s now fabled 1961 speech-namely, the substantial increase in NASA funding needed to make it happen. Are we still committed to advancing human spaceflight? What should a long-term goal be, and what does the United States need to do to achieve it? Pathways to Exploration explores the case for advancing this endeavor, drawing on the history of rationales for human spaceflight, examining the attitudes of stakeholders and the public, and carefully assessing the technical and fiscal realities. This report recommends maintaining the long-term focus on Mars as the horizon goal for human space exploration. With this goal in mind, the report considers funding levels necessary to maintain a robust tempo of execution, current research and exploration projects and the time/resources needed to continue them, and international cooperation that could contribute to the achievement of spaceflight to Mars. According to Pathways to Exploration, a successful U.S. program would require sustained national commitment and a budget that increases by more than the rate of inflation. In reviving a U.S. human exploration program capable of answering the enduring questions about humanity's destiny beyond our tiny blue planet, the nation will need to grapple with the attitudinal and fiscal realities of the nation today while staying true to a small but crucial set of fundamental principles for the conduct of exploration of the endless frontier. The recommendations of Pathways to Exploration provide a clear map toward a human spaceflight program that inspires students and citizens by furthering human exploration and discovery, while taking into account the long-term commitment necessary to achieve this goal.

From the interior of the Sun, to the upper atmosphere and near-space environment of Earth, and outward to a region far beyond Pluto where the Sun's influence wanes, advances during the past decade in space physics and solar physics--the disciplines NASA refers to as heliophysics--have yielded spectacular insights into the phenomena that affect our home in space. Solar and Space Physics, from the National Research Council's (NRC's) Committee for a Decadal Strategy in Solar and Space Physics, is the second NRC decadal survey in heliophysics. Building on the research accomplishments realized during the past decade, the report presents a program of basic and applied research for the period 2013-2022 that will improve scientific understanding of the mechanisms that drive the Sun's activity and the fundamental physical processes underlying near-Earth plasma dynamics, determine the physical interactions of Earth's atmospheric layers in the context of the connected Sun-Earth system, and enhance greatly the capability to provide realistic and specific forecasts of Earth's space environment that will better serve the needs of society. Although the recommended program is directed primarily at NASA and the National Science Foundation for action, the report also recommends actions by other federal agencies, especially the parts of the National Oceanic and Atmospheric Administration charged with the day-to-day (operational) forecast of space weather. In addition to the recommendations included in this summary, related recommendations are presented in this report.