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Research in biological and physical sciences in space provides the critical scientific and technological foundations that make space exploration possible. As humanity looks towards the Moon and Mars for future missions, this work is needed to help astronauts adapt and live in the harsh environments of space. Thriving in Space provides a roadmap for increasing national investment in biological and physical science research, from experiments to infrastructure to education. This report identifies key scientific questions, priorities, and ambitious research campaigns that will enable human space exploration and transform our understanding of how the universe works. Thriving in Space reviews the state of knowledge in the current and emerging areas of space-related biological and physical sciences research and generates recommendations for a comprehensive vision and strategy for a decade of transformative science at the frontiers of biological and physical sciences research in space. This report will help NASA define and align biological and physical sciences research to uniquely advance scientific knowledge, meet human and robotic exploration mission needs, and provide terrestrial benefits.

Among the various segments of society affected by the COVID-19 pandemic over the past year and a half, few were hit as hard as the aviation industry. At its worst point, in March 2020, passenger volumes for U.S. airlines had dropped more than 95 percent. Airlines, airports, aircraft manufacturers, and other components of the air travel system faced an unprecedented challenge, with threats to the health of passengers and crews combined with threats to the financial health of the entire system. To address the many COVID-related issues facing the aviation industry, on June 28-30, 2021, the Aeronautics and Space Engineering Board of the National Academies of Sciences, Engineering, and Medicine hosted a three-day workshop, Aviation After a Year of Pandemic - Economics, People, and Technology. Funded by the National Aeronautical and Space Administration and held remotely via Zoom, the workshop focused on four specific areas regarding the effects of COVID on the aviation industry: economics, personnel, technology, and next steps. This publication summarizes the presentation and discussion of the workshop.

The Transport Airplane Risk Assessment Methodology (TARAM) is a process for calculating risk associated with continued operational safety issues in the U.S. transport airplane fleet. TARAM is important because its risk-analysis calculations are used when making determinations of unsafe conditions in transport airplanes and when selecting and implementing corrective actions. This report assesses the TARAM process used by the FAA in its efforts to improve the overall safety of the transport airplane fleet. A healthy safety culture requires commitment to continuous improvement. This report provides recommendations to the FAA to address the gaps and strengthen the TARAM.

The National Academies of Sciences, Engineering, and Medicine convened a workshop on February 4th and 5th, 2021 to review the issues related to safety of passengers and employees in commercial air transportation, for domestic and international travel, during the COVID-19 pandemic. The workshop explored best practices to assess and mitigate COVID-19 transmission risks experienced during the travel chain, from the departure airport entrance to the destination airport exit. The workshop also identified areas where more research is needed to address gaps in understanding. This publication documents the presentations and discussions held during the workshop, and is presented as a synthesis of the workshop.

Space Nuclear Propulsion for Human Mars Exploration identifies primary technical and programmatic challenges, merits, and risks for developing and demonstrating space nuclear propulsion technologies of interest to future exploration missions. This report presents key milestones and a top-level development and demonstration roadmap for performance nuclear thermal propulsion and nuclear electric propulsion systems and identifies missions that could be enabled by successful development of each technology.

NASA created the University Leadership Initiative (ULI) to engage creative and innovative minds in the academic arena to identify significant aeronautics and aviation research challenges and define their unique approach to their solution. The ULI was started in 2015 as part of the larger University Innovation Project, with the goal of seeking new, innovative ideas that can support the U.S. aviation community and NASA's long-term aeronautics research goals, as established by its Aeronautics Research Mission Directorate. Assessing NASA's University Leadership Initiative reviews the ULI and makes recommendations to enhance program's impact to benefit students, faculty, industry, and the U.S. public.

Leadership in gas turbine technologies is of continuing importance as the value of gas turbine production is projected to grow substantially by 2030 and beyond. Power generation, aviation, and the oil and gas industries rely on advanced technologies for gas turbines. Market trends including world demographics, energy security and resilience, decarbonization, and customer profiles are rapidly changing and influencing the future of these industries and gas turbine technologies. Technology trends that define the technological environment in which gas turbine research and development will take place are also changing - including inexpensive, large scale computational capabilities, highly autonomous systems, additive manufacturing, and cybersecurity. It is important to evaluate how these changes influence the gas turbine industry and how to manage these changes moving forward. Advanced Technologies for Gas Turbines identifies high-priority opportunities for improving and creating advanced technologies that can be introduced into the design and manufacture of gas turbines to enhance their performance. The goals of this report are to assess the 2030 gas turbine global landscape via analysis of global leadership, market trends, and technology trends that impact gas turbine applications, develop a prioritization process, define high-priority research goals, identify high-priority research areas and topics to achieve the specified goals, and direct future research. Findings and recommendations from this report are important in guiding research within the gas turbine industry and advancing electrical power generation, commercial and military aviation, and oil and gas production.

Advanced aerial mobility is a newly emerging industry that aims to develop and operate new air vehicles potentially capable of safe, reliable, and low-noise vertical flight. The world has seen a recent increase in the adoption of electric vertical lift aircraft for urban, suburban and rural operations. These new innovations and technologies change the way that we move cargo and people, affecting industries across the economy. These changes will challenge today's airspace monitoring systems and regulatory environment. The U.S. government and its regulatory agencies need technical guidance to facilitate the development of these technologies, and to create the regulatory framework to foster the growth of this vertical flight industry to the benefit of the aviation industry. Advancing Aerial Mobility evaluates the potential benefits and challenges associated with this emerging industry. This report provides recommendations that seek to foster an environment in which the nation can maintain its leading position in developing, deploying, and embracing these new technologies. This publication presents a national vision for advanced aerial mobility, market evolution, and safety and security management.

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.

The 2011 National Research Council decadal survey on biological and physical sciences in space, Recapturing a Future for Space Exploration: Life and Physical Sciences Research for a New Era, was written during a critical period in the evolution of science in support of space exploration. The research agenda in space life and physical sciences had been significantly descoped during the programmatic adjustments of the Vision for Space Exploration in 2005, and this occurred in the same era as the International Space Station (ISS) assembly was nearing completion in 2011. Out of that period of change, Recapturing a Future for Space Exploration presented a cogent argument for the critical need for space life and physical sciences, both for enabling and expanding the exploration capabilities of NASA as well as for contributing unique science in many fields that can be enabled by access to the spaceflight environment. Since the 2011 publication of the decadal survey, NASA has seen tremendous change, including the retirement of the Space Shuttle Program and the maturation of the ISS. NASA formation of the Division of Space Life and Physical Sciences Research and Applications provided renewed focus on the research of the decadal survey. NASA has modestly regrown some of the budget of space life and physical sciences within the agency and engaged the U.S. science community outside NASA to join in this research. In addition, NASA has collaborated with the international space science community. This midterm assessment reviews NASA's progress since the 2011 decadal survey in order to evaluate the high-priority research identified in the decadal survey in light of future human Mars exploration. It makes recommendations on science priorities, specifically those priorities that best enable deep space exploration.

Prior to 2012, unmanned aircraft systems (UAS) technology had been primarily used by the military and hobbyists, but it has more recently transitioned to broader application, including commercial and scientific applications, as well as to expanded military use. These new uses encroach on existing structures for managing the nation's airspace and present significant challenges to ensure that UASs are coordinated safely and suitably with existing manned aircraft and air traffic management systems, particularly with the National Airspace System (NAS). Of particular concern is the interaction between human pilots, operators, or controllers and increasingly automated systems. Enhanced understanding of these interactions is essential to avoid unintended consequences, especially as new technologies emerge. In order to explore these issues, the National Academies of Sciences, Engineering, and Medicine organized a 2-day workshop in January 2018. This publication summarizes the presentations and discussions from the workshop.

Decades of continuous efforts to address known hazards in the national airspace system (NAS) and to respond to issues illuminated by analysis of incidents and accidents have made commercial airlines the safest mode of transportation. The task of maintaining a high level of safety for commercial airlines is complicated by the dynamic nature of the NAS. The number of flights by commercial transports is increasing; air traffic control systems and procedures are being modernized to increase the capacity and efficiency of the NAS; increasingly autonomous systems are being developed for aircraft and ground systems, and small aircraft—most notably unmanned aircraft systems—are becoming much more prevalent. As the NAS evolves to accommodate these changes, aviation safety programs will also need to evolve to ensure that changes to the NAS do not inadvertently introduce new risks. Real-time system-wide safety assurance (RSSA) is one of six focus areas for the National Aeronautics and Space Administration (NASA) aeronautics program. NASA envisions that an RSSA system would provide a continuum of information, analysis, and assessment that supports awareness and action to mitigate risks to safety. Maintaining the safety of the NAS as it evolves will require a wide range of safety systems and practices, some of which are already in place and many of which need to be developed. This report identifies challenges to establishing an RSSA system and the high-priority research that should be implemented by NASA and other interested parties in government, industry, and academia to expedite development of such a system.

When discussing the risk of introducing drones into the National Airspace System, it is necessary to consider the increase in risk to people in manned aircraft and on the ground as well as the various ways in which this new technology may reduce risk and save lives, sometimes in ways that cannot readily be accounted for with current safety assessment processes. This report examines the various ways that risk can be defined and applied to integrating these Unmanned Aircraft Systems (UAS) into the National Airspace System managed by the Federal Aviation Administration (FAA). It also identifies needs for additional research and developmental opportunities in this field.

The primary human activities that release carbon dioxide (CO2) into the atmosphere are the combustion of fossil fuels (coal, natural gas, and oil) to generate electricity, the provision of energy for transportation, and as a consequence of some industrial processes. Although aviation CO2 emissions only make up approximately 2.0 to 2.5 percent of total global annual CO2 emissions, research to reduce CO2 emissions is urgent because (1) such reductions may be legislated even as commercial air travel grows, (2) because it takes new technology a long time to propagate into and through the aviation fleet, and (3) because of the ongoing impact of global CO2 emissions. Commercial Aircraft Propulsion and Energy Systems Research develops a national research agenda for reducing CO2 emissions from commercial aviation. This report focuses on propulsion and energy technologies for reducing carbon emissions from large, commercial aircraft— single-aisle and twin-aisle aircraft that carry 100 or more passengers—because such aircraft account for more than 90 percent of global emissions from commercial aircraft. Moreover, while smaller aircraft also emit CO2, they make only a minor contribution to global emissions, and many technologies that reduce CO2 emissions for large aircraft also apply to smaller aircraft. As commercial aviation continues to grow in terms of revenue-passenger miles and cargo ton miles, CO2 emissions are expected to increase. To reduce the contribution of aviation to climate change, it is essential to improve the effectiveness of ongoing efforts to reduce emissions and initiate research into new approaches.

Historically, the United States has been a world leader in aerospace endeavors in both the government and commercial sectors. A key factor in aerospace leadership is continuous development of advanced technology, which is critical to U.S. ambitions in space, including a human mission to Mars. To continue to achieve progress, NASA is currently executing a series of aeronautics and space technology programs using a roadmapping process to identify technology needs and improve the management of its technology development portfolio. NASA created a set of 14 draft technology roadmaps in 2010 to guide the development of space technologies. In 2015, NASA issued a revised set of roadmaps. A significant new aspect of the update has been the effort to assess the relevance of the technologies by listing the enabling and enhancing technologies for specific design reference missions (DRMs) from the Human Exploration and Operations Mission Directorate and the Science Mission Directorate. NASA Space Technology Roadmaps and Priorities Revisited prioritizes new technologies in the 2015 roadmaps and recommends a methodology for conducting independent reviews of future updates to NASA's space technology roadmaps, which are expected to occur every 4 years.

The Federal Aviation Administration (FAA) is currently undertaking a broad program known as Next Generation Air Transportation System (NextGen) to develop, introduce, and certify new technologies into the National Airspace System. NextGen is a fundamentally transformative change that is being implemented incrementally over a period of many years. Currently, the FAA is putting into place the foundation that provides support for the future building blocks of a fully operational NextGen. NextGen is a challenging undertaking that includes ground systems, avionics installed in a wide range of aircraft, and procedures to take advantage of the new technology. Transformation in the Air assesses the FAA's plan for research on methods and procedures to improve both confidence in and the timeliness of certification of new technologies for their introduction into the National Airspace System. This report makes recommendations to include both ground and air elements and document the plan's relationship to the other activities and procedures required for certification and implementation into the National Airspace System.

Additive manufacturing has the potential to positively affect human spaceflight operations by enabling the in-orbit manufacture of replacement parts and tools, which could reduce existing logistics requirements for the International Space Station and future long-duration human space missions. The benefits of in-space additive manufacturing for robotic spacecraft are far less clear, although this rapidly advancing technology can also potentially enable space-based construction of large structures and, perhaps someday, substantially in the future, entire spacecraft. Additive manufacturing can also help to reimagine a new space architecture that is not constrained by the design and manufacturing confines of gravity, current manufacturing processes, and launch-related structural stresses. The specific benefits and potential scope of additive manufacturing remain undetermined. The realities of what can be accomplished today, using this technology on the ground, demonstrate the substantial gaps between the vision for additive manufacturing in space and the limitations of the technology and the progress that has to be made to develop it for space use. 3D Printing in Space evaluates the prospects of in-space additive manufacturing. This report examines the various technologies available and currently in development, and considers the possible impacts for crewed space operations and robotic spacecraft operations. Ground-based additive manufacturing is being rapidly developed by industry, and 3D Printing in Space discusses government-industry investments in technology development. According to this report, the International Space Station provides an excellent opportunity for both civilian and military research on additive manufacturing technology. Additive manufacturing presents potential opportunities, both as a tool in a broad toolkit of options for space-based activities and as a potential paradigm-changing approach to designing hardware for in-space activities. This report makes recommendations for future research, suggests objectives for an additive manufacturing roadmap, and envisions opportunities for cooperation and joint development.

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.

The development and application of increasingly autonomous (IA) systems for civil aviation is proceeding at an accelerating pace, driven by the expectation that such systems will return significant benefits in terms of safety, reliability, efficiency, affordability, and/or previously unattainable mission capabilities. IA systems range from current automatic systems such as autopilots and remotely piloted unmanned aircraft to more highly sophisticated systems that are needed to enable a fully autonomous aircraft that does not require a pilot or human air traffic controllers. These systems, characterized by their ability to perform more complex mission-related tasks with substantially less human intervention for more extended periods of time, sometimes at remote distances, are being envisioned for aircraft and for air traffic management and other ground-based elements of the national airspace system. Civil aviation is on the threshold of potentially revolutionary improvements in aviation capabilities and operations associated with IA systems. These systems, however, face substantial barriers to integration into the national airspace system without degrading its safety or efficiency. Autonomy Research for Civil Aviation identifies key barriers and suggests major elements of a national research agenda to address those barriers and help realize the benefits that IA systems can make to crewed aircraft, unmanned aircraft systems, and ground-based elements of the national airspace system. This report develops a set of integrated and comprehensive technical goals and objectives of importance to the civil aeronautics community and the nation. Autonomy Research for Civil Aviation will be of interest to U.S. research organizations, industry, and academia who have a role in meeting these goals.

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.

On June 15, 2011, the Air Force Space Command established a new vision, mission, and set of goals to ensure continued U.S. dominance in space and cyberspace mission areas. Subsequently, and in coordination with the Air Force Research Laboratory, the Space and Missile Systems Center, and the 14th and 24th Air Forces, the Air Force Space Command identified four long-term science and technology (S&T) challenges critical to meeting these goals. One of these challenges is to provide full-spectrum launch capability at dramatically lower cost, and a reusable booster system (RBS) has been proposed as an approach to meet this challenge. The Air Force Space Command asked the Aeronautics and Space Engineering Board of the National Research Council to conduct an independent review and assessment of the RBS concept prior to considering a continuation of RBS-related activities within the Air Force Research Laboratory portfolio and before initiating a more extensive RBS development program. The committee for the Reusable Booster System: Review and Assessment was formed in response to that request and charged with reviewing and assessing the criteria and assumptions used in the current RBS plans, the cost model methodologies used to fame [frame?] the RBS business case, and the technical maturity and development plans of key elements critical to RBS implementation. The committee consisted of experts not connected with current RBS activities who have significant expertise in launch vehicle design and operation, research and technology development and implementation, space system operations, and cost analysis. The committee solicited and received input on the Air Force launch requirements, the baseline RBS concept, cost models and assessment, and technology readiness. The committee also received input from industry associated with RBS concept, industry independent of the RBS concept, and propulsion system providers which is summarized in Reusable Booster System: Review and Assessment.

In the five decades since NASA was created, the agency has sustained its legacy from the National Advisory Committee on Aeronautics (NACA) in playing a major role in U.S. aeronautics research and has contributed substantially to United States preeminence in civil and military aviation. This preeminence has contributed significantly to the overall economy and balance of trade of the United States through the sales of aircraft throughout the world. NASA's contributions have included advanced flight control systems, de-icing devices, thrust-vectoring systems, wing fuselage drag reduction configurations, aircraft noise reduction, advanced transonic airfoil and winglet designs, and flight systems. Each of these contributions was successfully demonstrated through NASA flight research programs. Equally important, the aircraft industry would not have adopted these and similar advances without NASA flight demonstration on full-scale aircraft flying in an environment identical to that which the aircraft are to operate-in other words, flight research. Flight research is a tool, not a conclusion. It often informs simulation and modeling and wind tunnel testing. Aeronautics research does not follow a linear path from simulation to wind tunnels to flying an aircraft. The loss of flight research capabilities at NASA has therefore hindered the agency's ability to make progress throughout its aeronautics program by removing a primary tool for research. Recapturing NASA's Aeronautics Flight Research Capabilities discusses the motivation for NASA to pursue flight research, addressing the aspects of the committee's task such as identifying the challenges where research program success can be achieved most effectively through flight research. The report contains three case studies chosen to illustrate the state of NASA ARMD. These include the ERA program and the Fundamental Research Program's hypersonics and supersonics projects. Following these case studies, the report describes issues with the NASA ARMD organization and management and offers solutions. In addition, the chapter discusses current impediments to progress, including demonstrating relevancy to stakeholders, leadership, and the lack of focus relative to available resources. Recapturing NASA's Aeronautics Flight Research Capabilities concludes that the type and sophistication of flight research currently being conducted by NASA today is relatively low and that the agency's overall progress in aeronautics is severely constrained by its inability to actually advance its research projects to the flight research stage, a step that is vital to bridging the confidence gap. NASA has spent much effort protecting existing research projects conducted at low levels, but it has not been able to pursue most of these projects to the point where they actually produce anything useful. Without the ability to actually take flight, NASA's aeronautics research cannot progress, cannot make new discoveries, and cannot contribute to U.S. aerospace preeminence.

In February 2009, the commercial communications satellite Iridium 33 collided with the Russian military communications satellite Cosmos 2251. The collision, which was not the first recorded between two satellites in orbit—but the most recent and alarming—produced thousands of pieces of debris, only a small percentage of which could be tracked by sensors located around the world. In early 2007, China tested a kinetic anti-satellite weapon against one of its own satellites, which also generated substantial amounts of space debris. These collisions highlighted the importance of maintaining accurate knowledge, and the associated uncertainty, of the orbit of each object in space. These data are needed to predict close approaches of space objects and to compute the probability of collision so that owners/operators can decide whether or not to make a collision avoidance maneuver by a spacecraft with such capability. The space object catalog currently contains more than 20,000 objects, and when the planned space fence radar becomes operational this number is expected to exceed 100,000. A key task is to determine if objects might come closer to each other, an event known as'conjunction,'and the probability that they might collide. The U.S. Air Force is the primary U.S. government organization tasked with maintaining the space object catalog and data on all space objects. This is a complicated task, involving collecting data from a multitude of different sensors-many of which were not specifically designed to track orbiting objects-and fusing the tracking data along with other data, such as data from atmospheric models, to provide predictions of where objects will be in the future. The Committee for the Assessment of the U.S. Air Force's Astrodynamic Standards collected data and heard from numerous people involved in developing and maintaining the current astrodynamics standards for the Air Force Space Command (AFSPC), as well as representatives of the user community, such as NASA and commercial satellite owners and operators. Preventing collisions of space objects, regardless of their ownership, is in the national security interested of the United States. Continuing Kepler's Quest makes recommendations to the AFSPC in order for it to create and expand research programs, design and develop hardware and software, as well as determine which organizations to work with to achieve its goals.

NASA's Office of the Chief Technologist (OCT) has begun to rebuild the advanced space technology program in the agency with plans laid out in 14 draft technology roadmaps. It has been years since NASA has had a vigorous, broad-based program in advanced space technology development and its technology base has been largely depleted. However, success in executing future NASA space missions will depend on advanced technology developments that should already be underway. Reaching out to involve the external technical community, the National Research Council (NRC) considered the 14 draft technology roadmaps prepared by OCT and ranked the top technical challenges and highest priority technologies that NASA should emphasize in the next 5 years. This report provides specific guidance and recommendations on how the effectiveness of the technology development program managed by OCT can be enhanced in the face of scarce resources.

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.

Derelict satellites, equipment and other debris orbiting Earth (aka space junk) have been accumulating for many decades and could damage or even possibly destroy satellites and human spacecraft if they collide. During the past 50 years, various National Aeronautics and Space Administration (NASA) communities have contributed significantly to maturing meteoroid and orbital debris (MMOD) programs to their current state. Satellites have been redesigned to protect critical components from MMOD damage by moving critical components from exterior surfaces to deep inside a satellite's structure. Orbits are monitored and altered to minimize the risk of collision with tracked orbital debris. MMOD shielding added to the International Space Station (ISS) protects critical components and astronauts from potentially catastrophic damage that might result from smaller, untracked debris and meteoroid impacts. Limiting Future Collision Risk to Spacecraft: An Assessment of NASA's Meteoroid and Orbital Debris Program examines NASA's efforts to understand the meteoroid and orbital debris environment, identifies what NASA is and is not doing to mitigate the risks posed by this threat, and makes recommendations as to how they can improve their programs. While the report identified many positive aspects of NASA's MMOD programs and efforts including responsible use of resources, it recommends that the agency develop a formal strategic plan that provides the basis for prioritizing the allocation of funds and effort over various MMOD program needs. Other necessary steps include improvements in long-term modeling, better measurements, more regular updates of the debris environmental models, and other actions to better characterize the long-term evolution of the debris environment.

As the National Aeronautics and Space Administration (NASA) retires the Space Shuttle and shifts involvement in International Space Station (ISS) operations, changes in the role and requirements of NASA's Astronaut Corps will take place. At the request of NASA, the National Research Council (NRC) addressed three main questions about these changes: what should be the role and size of Johnson Space Center's (JSC) Flight Crew Operations Directorate (FCOD); what will be the requirements of astronaut training facilities; and is the Astronaut Corps'fleet of training aircraft a cost-effective means of preparing astronauts for NASA's spaceflight program? This report presents an assessment of several issues driven by these questions. This report does not address explicitly the future of human spaceflight.

For the National Aeronautics and Space Administration (NASA) to achieve many of its space science and exploration goals over the next several decades, dramatic advances in space technology will be necessary. NASA has developed a set of 14 draft roadmaps to guide the development of such technologies under the leadership of the NASA Office of the Chief Technologist (OCT). Each roadmap focuses on a particular technology area. OCT requested that the National Research Council conduct a study to review the draft roadmaps, gather and assess relevant community input, and make recommendations and suggest priorities to inform NASA's decisions as it finalizes its roadmaps. The success of OCT's technology development program is essential, because technological breakthroughs have long been the foundation of NASA's successes, from its earliest days, to the Apollo program, to a vast array of space science missions and the International Space Station. An Interim Report of NASA's Technology Roadmap identifies some gaps in the technologies included in the individual roadmaps. The report suggests that the effectiveness of the NASA space technology program can be enhanced by employing proven management practices and principles including increasing program stability, addressing facility issues, and supporting adequate flight tests of new technologies. This interim report provides several additional observations that will be expanded on in the final report to be released in 2012.

A Summary of the Workshop to Identify the Gaps and Possible Directions for NASA's Meteoroid and Orbital Debris Programs summarizes the two-day workshop held on March 9-10, 2011, where various stakeholders presented diverse perspectives on matters concerning NASA Micrometeoroid and Orbital Debris (MMOD) programs, NASA mission operators, the role and relationships of NASA MMOD programs to other federal agencies, MMOD and the commercial industry, and orbital debris retrieval and removal. The report assesses NASA's existing efforts, policies, and organizations with regard to orbital debris and micrometeoroids by creating advisory dialogue on potential opportunities for program enhancement and maintenance practices.

Over the past 5 years or more, there has been a steady and significant decrease in NASA's laboratory capabilities, including equipment, maintenance, and facility upgrades. This adversely affects the support of NASA's scientists, who rely on these capabilities, as well as NASA's ability to make the basic scientific and technical contributions that others depend on for programs of national importance. The fundamental research community at NASA has been severely impacted by the budget reductions that are responsible for this decrease in laboratory capabilities, and as a result NASA's ability to support even NASA's future goals is in serious jeopardy.

In response to requests from Congress, NASA asked the National Research Council to undertake a decadal survey of life and physical sciences in microgravity. Developed in consultation with members of the life and physical sciences communities, the guiding principle for the study is to set an agenda for research for the next decade that will allow the use of the space environment to solve complex problems in life and physical sciences so as to deliver both new knowledge and practical benefits for humankind as we become a spacefaring people. The project's statement of task calls for delivery of two books—an interim report and a final survey report. Although the development of specific recommendations is deferred until the final book, this interim report does attempt to identify programmatic needs and issues to guide near-term decisions that are critical to strengthening the organization and management of life and physical sciences research at NASA.

Advancing the state of aviation safety is a central mission of the National Aeronautics and Space Administration (NASA). Congress requested this review of NASA's aviation safety-related research programs, seeking an assessment of whether the programs have well-defined, prioritized, and appropriate research objectives; whether resources have been allocated appropriately among these objectives; whether the programs are well coordinated with the safety research programs of the Federal Aviation Administration; and whether suitable mechanisms are in place for transitioning the research results into operational technologies and procedures and certification activities in a timely manner. Advancing Aeronautical Safety contains findings and recommendations with respect to each of the main aspects of the review sought by Congress. These findings indicate that NASA's aeronautics research enterprise has made, and continues to make, valuable contributions to aviation system safety but it is falling short and needs improvement in some key respects.

From September 2007 to June 2008 the Space Studies Board conducted an international public seminar series, with each monthly talk highlighting a different topic in space and Earth science. The principal lectures from the series are compiled in Forging the Future of Space Science. The topics of these events covered the full spectrum of space and Earth science research, from global climate change, to the cosmic origins of life, to the exploration of the Moon and Mars, to the scientific research required to support human spaceflight. The prevailing messages throughout the seminar series as demonstrated by the lectures in this book are how much we have accomplished over the past 50 years, how profound are our discoveries, how much contributions from the space program affect our daily lives, and yet how much remains to be done. The age of discovery in space and Earth science is just beginning. Opportunities abound that will forever alter our destiny.

The United States spends approximately $4 million each year searching for near-Earth objects (NEOs). The objective is to detect those that may collide with Earth. The majority of this funding supports the operation of several observatories that scan the sky searching for NEOs. This, however, is insufficient in detecting the majority of NEOs that may present a tangible threat to humanity. A significantly smaller amount of funding supports ways to protect the Earth from such a potential collision or'mitigation.'In 2005, a Congressional mandate called for NASA to detect 90 percent of NEOs with diameters of 140 meters of greater by 2020. Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies identifies the need for detection of objects as small as 30 to 50 meters as these can be highly destructive. The book explores four main types of mitigation including civil defense,'slow push'or'pull'methods, kinetic impactors and nuclear explosions. It also asserts that responding effectively to hazards posed by NEOs requires national and international cooperation. Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies is a useful guide for scientists, astronomers, policy makers and engineers.

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.

Numerous countries and regions now have very active space programs, and the number is increasing. These maturing capabilities around the world create a plethora of potential partners for cooperative space endeavors, while at the same time heightening competitiveness in the international space arena. This book summarizes a public workshop held in November 2008 for the purpose of reviewing past and present cooperation, coordination, and competition mechanisms for space and Earth science research and space exploration; identifying significant lessons learned; and discussing how those lessons could best be applied in the future, particularly in the areas of cooperation and collaboration. Presentations and initial discussion focused on past and present experiences in international cooperation and competition to identify'lessons learned.'Those lessons learned were then used as the starting point for subsequent discussions on the most effective ways for structuring future cooperation or coordination in space and Earth science research and space exploration. The goal of the workshop was not to develop a specific model for future cooperation or coordination, but rather to explore the advantages and disadvantages of various approaches and stimulate further deliberation on this important topic.

The NASA Institute for Advanced Concepts (NIAC) was formed in 1998 to provide an independent source of advanced aeronautical and space concepts that could dramatically impact how NASA develops and conducts its missions. Until the program's termination in August 2007, NIAC provided an independent open forum, a high-level point of entry to NASA for an external community of innovators, and an external capability for analysis and definition of advanced aeronautics and space concepts to complement the advanced concept activities conducted within NASA. Throughout its 9-year existence, NIAC inspired an atmosphere for innovation that stretched the imagination and encouraged creativity. As requested by Congress, this volume reviews the effectiveness of NIAC and makes recommendations concerning the importance of such a program to NASA and to the nation as a whole, including the proper role of NASA and the federal government in fostering scientific innovation and creativity and in developing advanced concepts for future systems. Key findings and recommendations include that in order to achieve its mission, NASA must have, and is currently lacking, a mechanism to investigate visionary, far-reaching advanced concepts. Therefore, a NIAC-like entity should be reestablished to fill this gap.

The National Research Council of the National Academies was requested by the National Aeronautics and Space Administration (NASA) to perform an independent assessment of NASA's National Aviation Operations Monitoring Service (NAOMS) project, which was a survey administered to pilots from April 2001 through December 2004. The NRC reviewed various aspects of the NAOMS project, including the survey methodology, and conducted a limited analysis of the publicly available survey data. An Assessment of NASA's National Aviation Operations Monitoring Service presents the resulting analyses and findings.

The United States is currently the only country with an active, government-sponsored effort to detect and track potentially hazardous near-Earth objects (NEOs). Congress has mandated that NASA detect and track 90 percent of NEOs that are 1 kilometer in diameter or larger. These objects represent a great potential hazard to life on Earth and could cause global destruction. NASA is close to accomplishing this goal. Congress has more recently mandated that by 2020 NASA should detect and track 90 percent of NEOs that are 140 meters in diameter or larger, a category of objects that is generally recognized to represent a very significant threat to life on Earth if they strike in or near urban areas. Achieving this goal may require the building of one or more additional observatories, possibly including a space-based observatory. Congress directed NASA to ask the National Research Council to review NASA's near-Earth object programs. This interim report addresses some of the issues associated with the survey and detection of NEOs. The final report will contain findings and recommendations for survey and detection, characterization, and mitigation of near-Earth objects based on an integrated assessment of the problem.

As civil space policies and programs have evolved, the geopolitical environment has changed dramatically. Although the U.S. space program was originally driven in large part by competition with the Soviet Union, the nation now finds itself in a post-Cold War world in which many nations have established, or are aspiring to develop, independent space capabilities. Furthermore discoveries from developments in the first 50 years of the space age have led to an explosion of scientific and engineering knowledge and practical applications of space technology. The private sector has also been developing, fielding, and expanding the commercial use of space-based technology and systems. Recognizing the new national and international context for space activities, America's Future in Space is meant to advise the nation on key goals and critical issues in 21st century U.S. civil space policy.

Without major changes, the current air transportation system will be unable to accommodate the expected increase in demand by 2025. One proposal to address this problem is to use the Global Positioning System to enable aircraft to fly more closely spaced. This approach, however, might be limited by the wake turbulence problem, which can be a safety hazard when smaller aircraft follow relatively larger aircraft too closely. To examine how this potential hazard might be reduced, Congress in 2005 directed NASA to request a study from the NRC to assess the federal wake turbulence R&D program. This book provides a description of the problem, an assessment of the organizational challenges to addressing wake turbulence, an analysis of the technical challenges in wake turbulence, and a proposal for a wake turbulence program plan. A series of recommendations for addressing the wake turbulence challenge are also given.

To meet the objectives of the Vision for Space Exploration (VSE), NASA must develop a wide array of enabling technologies. For this purpose, NASA established the Exploration Technology Development Program (ETDP). Currently, ETDP has 22 projects underway. In the report accompanying the House-passed version of the FY2007 appropriations bill, the agency was directed to request from the NRC an independent assessment of the ETDP. This interim report provides an assessment of each of the 22 projects including a quality rating, an analysis of how effectively the research is being carried out, and the degree to which the research is aligned with the VSE. To the extent possible, the identification and discussion of various cross-cutting issues are also presented. Those issues will be explored and discussed in more detail in the final report.

In January 2004, President George W. Bush announced the Vision for Space Exploration (VSE), which instructed NASA to'Extend human presence across the solar system, starting with a human return to the Moon by the year 2020, in preparation for human exploration of Mars and other destinations,'among other objectives. As acknowledged in the VSE, significant technology development will be necessary to accomplish the goals it articulates. NASA's Exploration Technology Development Program (ETDP) is designed to support, develop, and ultimately provide the necessary technologies to meet the goals of the VSE. This book, a review of the ETDP, is broadly supportive of the intent and goals of the VSE, and finds the ETDP is making progress towards the stated goals of technology development. However, the ETDP is operating within significant constraints which limit its ability to successfully accomplish those goals-the still dynamic nature of the Constellation Program requirements, the constraints imposed by a limited budget, the aggressive time scale of early technology deliverables, and the desire to fully employ the NASA workforce.

The U.S. aviation industry, airline passengers, aircraft pilots, airports, and airline companies are all facing challenges. The air transportation system is experiencing unprecedented and increasing levels of use. The federal government understands the critical need to update the U.S. air transportation system, and plans to implement the Next Generation Air Transportation System (NextGen) by 2025. This system is an example of active networking technology that updates itself with real-time shared information and tailors itself to the individual needs of all U.S. aircraft, stressing adaptability by enabling aircraft to immediately adjust to ever-changing factors. On April 1-2, 2008, a workshop was held at the National Academies to gather reactions to the research and development aspects of the Joint Planning and Development Office's baseline Integrated Work Plan (IWP), which is designed to increase the efficiency of airport and air space use in the United States. This book provides a summary of the workshop, which included presentations on the following topics: Airport operations and support; Environmental management; Air navigation operations, Air navigation support, and flight operation support; Positioning, navigation, and timing services and surveillance; Weather information services; Safety management; Net-centric infrastructure services and operations; and Layered adaptive security.

In 2004, the NRC released a workshop report about the future direction of the U.S. civil space program. At the same time, the Administration announced the Vision for Space Exploration, and in June 2004, it issued a report that articulated a balanced space program for human and robotic exploration and science. Subsequent NRC reports, however, have noted that NASA has not been given the resources to carry out this broad-based program. This challenge, along with others faced by the U.S. civil space program, stimulated the NRC to form an ad hoc committee to organize a second workshop, held in November 2007, to address the space program's future directions. The workshop's goal was to air a range of views and perspectives so as to inform discussions of these questions by policymakers and the public. This book presents a summary of the workshop.

To begin implementation of the Vision for Space Exploration (recently renamed “United States Space Exploration Policy”), NASA has begun development of new launch vehicles and a human-carrying spacecraft that are collectively called the Constellation System. In November 2007, NASA asked the NRC to evaluate the potential for the Constellation System to enable new space science opportunities. For this interim report, 11 existing'Vision Mission'studies of advanced space science mission concepts inspired by earlier NASA forward-looking studies were evaluated. The focus was to assess the concepts and group them into two categories: more-deserving or less deserving of future study. This report presents a description of the Constellation System and its opportunities for enabling new space science opportunities, and a systematic analysis of the 11 Vision Mission studies. For the final report, the NRC issued a request for information to the relevant communities to obtain ideas for other mission concepts that will be assessed by the study committee, and several issues addressed only briefly in the interim report will be explored more fully.

As part of the Vision for Space Exploration (VSE), NASA is planning for humans to revisit the Moon and someday go to Mars. An important consideration in this effort is protection against the exposure to space radiation. That radiation might result in severe long-term health consequences for astronauts on such missions if they are not adequately shielded. To help with these concerns, NASA asked the NRC to further the understanding of the risks of space radiation, to evaluate radiation shielding requirements, and recommend a strategic plan for developing appropriate mitigation capabilities. This book presents an assessment of current knowledge of the radiation environment; an examination of the effects of radiation on biological systems and mission equipment; an analysis of current plans for radiation protection; and a strategy for mitigating the risks to VSE astronauts.

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.