Space Studies Board – författare
Visar alla böcker från författaren Space Studies Board. Handla med fri frakt och snabb leverans.
152 produkter
152 produkter
Strategy for the Detection and Study of Other Planetary Systems and Extrasolar Planetary Materials
1990-2000
Häftad, Engelska, 1990
1 656 kr
Tillfälligt slut
This volume addresses a new opportunity in the planetary sciences--to extend our exploration outward to discover and study planetary systems that may have formed or are forming around other stars. It concludes that a coordinated program of astronomical observation, laboratory research, theoretical development, and understanding of the dynamics and origins of whatever may be found would be a technologically feasible and potentially richly rewarding extension of the study of bodies within the solar system.
Search for Life's Origins
Progress and Future Directions in Planetary Biology and Chemical Evolution
Häftad, Engelska, 1990
1 747 kr
Tillfälligt slut
The field of planetary biology and chemical evolution draws together experts in astronomy, paleobiology, biochemistry, and space science who work together to understand the evolution of living systems. This field has made exciting discoveries that shed light on how organic compounds came together to form self-replicating molecules--the origin of life. This volume updates that progress and offers recommendations on research programs--including an ambitious effort centered on Mars--to advance the field over the next 10 to 15 years. The book presents a wide range of data and research results on these and other issues: * The biogenic elements and their interaction in the interstellar clouds and in solar nebulae. * Early planetary environments and the conditions that lead to the origin of life. * The evolution of cellular and multicellular life. * The search for life outside the solar system. This volume will become required reading for anyone involved in the search for life's beginnings--including exobiologists, geoscientists, planetary scientists, and U.S. space and science policymakers.
Space Physics Paradox
Why Has Increased Funding Been Accompanied by Decreased Effectiveness in the Conduct of Space Physics Research?
Häftad, Engelska, 1994
1 232 kr
Tillfälligt slut
This book investigates and analyzes several disturbing trends in government support for space physics research over the past decade. The authors identify funding and management problems that thwart cost efficiency within this discipline, and suggest possible solutions. The volume also has broader implications for anyone engaged in research or in the funding and organizing of space physics research.
1 301 kr
Tillfälligt slut
The Space Studies Board of the National Research Council (NRC) serves as the primary adviser to the National Aeronautics and Space Administration (NASA) on planetary protection policy, the purpose of which is to preserve conditions for future biological and organic exploration of planets and other solar system objects and to protect Earth and its biosphere from potential extraterrestrial sources of contamination. In October 1995 the NRC received a letter from NASA requesting that the Space Studies Board examine and provide advice on planetary protection issues related to possible sample-return missions to near-Earth solar system bodies.
1 129 kr
Tillfälligt slut
1 070 kr
Tillfälligt slut
1 301 kr
Tillfälligt slut
U.S.-European Collaboration in Space Science reviews the past 30 years of space-based research across the Atlantic. The book, which was prepared jointly with the European Space Science Committee (under the aegis of the European Science Foundation) begins with a broad survey of the historical and political context of U.S.-European cooperation and collaboration in space. The focus of the book is a set of 13 U.S.-European missions in astrophysics, space physics, planetary sciences, earth sciences, and life and microgravity research that illustrate "lessons learned" on the evolution of the cooperation, mission planning and scheduling, international agreements, cost-sharing, management, and scientific output. These lessons form the basis of the joint committee's findings and recommendations, which serve to improve the future conduct and enhance the scientific output of U.S.-European cooperation and collaboration in space science.
1 358 kr
Tillfälligt slut
During 1988, the National Research Council's Space Science Board reorganized itself to more effectively address NASA's advisory needs. The Board's scope was broadened: it was renamed the Space Studies Board and, among other new initiatives, the Committee on Human Exploration was created. The new committee was intended to focus on the scientific aspects of human exploration programs, rather than engineering issues. Their research led to three reports: Scientific Prerequisites for the Human Exploration of Space published in 1993, Scientific Opportunities in the Human Exploration of Space published in 1994, and Science Management in the Human Exploration of Space published in 1997. These three reports are collected and reprinted in this volume in their entirety as originally published.
1 290 kr
Tillfälligt slut
In the last decade, our knowledge of the outer solar system has been transformed as a result of the Voyager 2 encounter with Neptune and its satellite Triton and from Earth-based observations of the Pluto-Charon system. However, the planetary system does not simply end at the distance of Pluto and Neptune. In the past few years, dozens of bodies have been discovered in near-circular, low inclination orbits near or beyond the orbit of Neptune. These bodies are now believed to be directly related to each other and to Pluto, Charon, and Triton, and as a class they define and occupy the inner boundary of a hitherto unexplored component of the solar system, the trans-neptunian region. Exploring the Trans-Neptunian Solar System reviews current understanding of the trans-neptunian solar system and makes recommendations for the future exploration of this distant realm.
965 kr
Tillfälligt slut
Construction of the international space station, scheduled to start in late 1998, ushers in a new era for laboratory sciences in space. This is especially true for space life sciences, which include not only the use of low gravity as an experimental parameter to study fundamental biological processes but also the study of the serious physiological changes that occur in astronauts as they remain in space for increasingly longer missions. This book addresses both of these aspects and provides a comprehensive review of ground-based and space research in eleven disciplines, ranging from bone physiology to plant biology. It also offers detailed, prioritized recommendations for research during the next decade, which are expected to have a considerable impact on the direction of NASA's research program. The volume is also a valuable reference tool for space and life scientists.
1 290 kr
Tillfälligt slut
Comets and asteroids are in some sense the fossils of the solar system. They have avoided most of the drastic physical processing that shaped the planets and thus represent more closely the properties of the primordial solar nebula. What processing has taken place is itself of interest in decoding the history of our solar neighborhood. Near-Earth objects are also of interest because one or more large ones have been blamed for the rare but devastating events that caused mass extinctions of species on our planet, as attested by recent excitement over the impending passage of asteroid 1997 XF11. The comets and asteroids whose orbits bring them close to Earth are clearly the most accessible to detailed investigation, both from the ground and from spacecraft. When nature kindly delivers the occasional asteroid to the surface of Earth as a meteorite, we can scrutinize it closely in the laboratory; a great deal of information about primordial chemical composition and primitive processes has been gleaned from such objects. This report reviews the current state of research on near-Earth objects and considers future directions.Attention is paid to the important interplay between ground-based investigations and spaceborne observation or sample collection and return. This is particularly timely since one U.S. spacecraft is already on its way to rendezvous with a near-Earth object, and two others plus a Japanese mission are being readied for launch. In addition to scientific issues, the report considers technologies that would enable further advances in capability and points out the possibilities for including near-Earth objects in any future expansion of human exploration beyond low Earth orbit.
Report of the Workshop on Biology-based Technology to Enhance Human Well-being and Function in Extended Space Exploration
Häftad, Engelska, 1998
1 290 kr
Tillfälligt slut
Evaluating the Biological Potential in Samples Returned from Planetary Satellites and Small Solar System Bodies
Framework for Decision Making
Häftad, Engelska, 1998
1 312 kr
Tillfälligt slut
For the first time since the Apollo program, NASA and space agencies abroad have plans to bring samples to Earth from elsewhere in the solar system. There are missions in various stages of definition to gather material over the next decade from Mars, an asteroid, comets, the satellites of Jupiter, and the interplanetary dust. Some of these targets, most especially Jupiter's satellites Europa and Ganymede, now appear to have the potential for harboring living organisms. This book considers the possibility that life may have originated or existed on a body from which a sample might be taken and the possibility that life still exists on the body either in active form or in a form that could be reactiviated. It also addresses the potential hazard to terrestrial ecosystems from extraterrestrial life if it exists in a returned sample. Released at the time of the Internationl Committee on Space Research General Assembly, the book has already established the basis for plans for small body sample retruns in the international space research community.
Supporting Research and Data Analysis in NASA's Science Programs
Engines for Innovation and Synthesis
Häftad, Engelska, 1998
1 244 kr
Tillfälligt slut
Effective science, clearly a mandate for the National Aeronautics and Space Administration (NASA), involves asking significant questions about the physical and biological world and seeking definitive answers. Its product is new knowledge that has value to the nation. NASA's flight projects are highly visible and usually the most costly elements of this process, but they are only a part of the science enterprise. Flight projects are founded on research that defines clear scientific goals and questions, designs missions to address those questions, and develops the required technologies to accomplish the missions. This research is funded primarily by NASA's research and analysis (R&A) programs. Data from flight projects are transformed into knowledge through analysis and synthesis-research that is funded both by R&A and by the data analysis (DA) portion of mission operations and data analysis (MO&DA) programs. R&A and DA programs are the subject of this report and are grouped for convenience under the heading of research and data analysis (R&DA).
1 290 kr
Tillfälligt slut
For the last several decades, the Committee on Planetary and Lunar Exploration (COMPLEX) has advocated a systematic approach to exploration of the solar system; that is, the information and understanding resulting from one mission provide the scientific foundations that motivate subsequent, more elaborate investigations. COMPLEX's 1994 report, An Integrated Strategy for the Planetary Sciences: 1995-2010,1 advocated an approach to planetary studies emphasizing "hypothesizing and comprehending" rather than "cataloging and categorizing." More recently, NASA reports, including The Space Science Enterprise Strategic Plan2 and, in particular, Mission to the Solar System: Exploration and Discovery-A Mission and Technology Roadmap,3 have outlined comprehensive plans for planetary exploration during the next several decades. The missions outlined in these plans are both generally consistent with the priorities outlined in the Integrated Strategy and other NRC reports,4,5 and are replete with examples of devices embodying some degree of mobility in the form of rovers, robotic arms, and the like.Because the change in focus of planetary studies called for in the Integrated Strategy appears to require an evolutionary change in the technical means by which solar system exploration missions are conducted, the Space Studies Board charged COMPLEX to review the science that can be uniquely addressed by mobility in planetary environments.
1 450 kr
Tillfälligt slut
1 301 kr
Tillfälligt slut
Since its discovery in 1610, Europa - one of Jupiter's four large moons - has been an object of interest to astronomers and planetary scientists. Much of this interest stems from observations made by NASA's Voyager and Galileo spacecraft and from Earth-based telescopes indicating that Europa's surface is quite young, with very little evidence of cratering, and made principally of water ice. More recently, theoretical models of the jovian system and Europa have suggested that tidal heating may have resulted in the existence of liquid water, and perhaps an ocean, beneath Europa's surface. NASA's ongoing Galileo mission has profoundly expanded our understanding of Europa and the dynamics of the jovian system, and may allow us to constrain theoretical models of Europa's subsurface structure. Meanwhile, since the time of the Voyagers, there has been a revolution in our understanding of the limits of life on Earth. Life has been detected thriving in environments previously thought to be untenable - around hydrothermal vent systems on the seafloor, deep underground in basaltic rocks, and within polar ice.Elsewhere in the solar system, including on Europa, environments thought to be compatible with life as we know it on Earth are now considered possible, or even probable. Spacecraft missions are being planned that may be capable of proving their existence. Against this background, the Space Studies Board charged its Committee on Planetary and Lunar Exploration (COMPLEX) to perform a comprehensive study to assess current knowledge about Europa, outline a strategy for future spacecraft missions to Europa, and identify opportunities for complementary Earth-based studies of Europa. (See the preface for a full statement of the charge.)
1 347 kr
Tillfälligt slut
How small can a free-living organism be? On the surface, this question is straightforward-in principle, the smallest cells can be identified and measured. But understanding what factors determine this lower limit, and addressing the host of other questions that follow on from this knowledge, require a fundamental understanding of the chemistry and ecology of cellular life. The recent report of evidence for life in a martian meteorite and the prospect of searching for biological signatures in intelligently chosen samples from Mars and elsewhere bring a new immediacy to such questions. How do we recognize the morphological or chemical remnants of life in rocks deposited 4 billion years ago on another planet? Are the empirical limits on cell size identified by observation on Earth applicable to life wherever it may occur, or is minimum size a function of the particular chemistry of an individual planetary surface? These questions formed the focus of a workshop on the size limits of very small organisms, organized by the Steering .Group for the Workshop on Size Limits of Very Small Microorganisms and held on October 22 and 23, 1998.Eighteen invited panelists, representing fields ranging from cell biology and molecular genetics to paleontology and mineralogy, joined with an almost equal number of other participants in a wide-ranging exploration of minimum cell size and the challenge of interpreting micro- and nano-scale features of sedimentary rocks found on Earth or elsewhere in the solar system. This document contains the proceedings of that workshop. It includes position papers presented by the individual panelists, arranged by panel, along with a summary, for each of the four sessions, of extensive roundtable discussions that involved the panelists as well as other workshop participants.
1 221 kr
Tillfälligt slut
A major objective of the International Space Station is learning how to cope with the inherent risks of human spaceflight--how to live and work in space for extended periods. The construction of the station itself provides the first opportunity for doing so. Prominent among the challenges associated with ISS construction is the large amount of time that astronauts will be spending doing extravehicular activity (EVA), or "space walks." EVAs from the space shuttle have been extraordinarily successful, most notably the on-orbit repair of the Hubble Space Telescope. But the number of hours of EVA for ISS construction exceeds that of the Hubble repair mission by orders of magnitude. Furthermore, the ISS orbit has nearly twice the inclination to Earth's equator as Hubble's orbit, so it spends part of every 90-minute circumnavigation at high latitudes, where Earth's magnetic field is less effective at shielding impinging radiation. This means that astronauts sweeping through these regions will be considerably more vulnerable to dangerous doses of energetic particles from a sudden solar eruption.Radiation and the International Space Station estimates that the likelihood of having a potentially dangerous solar event during an EVA is indeed very high. This report recommends steps that can be taken immediately, and over the next several years, to provide adequate warning so that the astronauts can be directed to take protective cover inside the ISS or shuttle. The near-term actions include programmatic and operational ways to take advantage of the multiagency assets that currently monitor and forecast space weather, and ways to improve the in situ measurements and the predictive power of current models.
1 290 kr
Tillfälligt slut
Under current NASA plans, investigations in the area of biotechnology will be a significant component of the life sciences research to be conducted on the International Space Station (ISS). They encompass work on cell science and studies of the use of microgravity to grow high-quality protein crystals. Both these subdisciplines are advancing rapidly in terrestrial laboratories, fueled by federal and industrial research budgets that dwarf those of NASA's life science program. Forging strong and fruitful connections between the space investigations and laboratory-bench biologists, a continual challenge for NASA' s life sciences program, is thus of great importance to ensuring the excellence of ISS research. This report evaluates the plan for NASA's biotechnology facility on the ISS and the scientific context that surrounds it, and makes recommendations on how the facility can be made more effective. In addition to questions about optimizing the instrumentation, the report addresses strategies for enhancing the scientific impact and improving the outreach to mainstream terrestrial biology.No major redirection of effort is called for, but collectively the specific, targeted changes recommended by the task group would have a major effect on the conduct of biotechnology research in space.
Assessment of Mission Size Trade-offs for NASA's Earth and Space Science Missions
Häftad, Engelska, 2000
1 232 kr
Tillfälligt slut
Assessment of Mission Size Trade-offs for NASA's Earth and Space Science Missions addresses fundamental issues of mission architecture in the nation's scientific space program and responds to the FY99 Senate conference report, which requested that NASA commission a study to assess the strengths and weaknesses of small, medium, and large missions. This report evaluates the general strengths and weaknesses of small, medium, and large missions in terms of their potential scientific productivity, responsiveness to evolving opportunities, ability to take advantage of technological progress, and other factors that may be identified during the study; identifies which elements of the SSB and NASA science strategies will require medium or large missions to accomplish high-priority science objectives; and recommends general principles or criteria for evaluating the mix of mission sizes in Earth and space science programs.Assessment of Mission Size Trade-offs for NASA's Earth and Space Science Missions considers not only scientific, technological, and cost trade-offs, but also institutional and structural issues pertaining to the vigor of the research community, government-industry university partnerships, graduate student training, and the like.
1 232 kr
Tillfälligt slut
Remote observations of Earth from space serve an extraordinarily broad range of purposes, resulting in extraordinary demands on those at the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and elsewhere who must decide how to execute them. In research, Earth observations promise large volumes of data to a variety of disciplines with differing needs for measurement type, simultaneity, continuity, and long-term instrument stability. Operational needs, such as weather forecasting, add a distinct set of requirements for continual and highly reliable monitoring of global conditions. The Role of Small Satelites in NASA and NOAA Earth Observation Porgrams confronts these diverse requirements and assesses how they might be met by small satellites. In the past, the preferred architecture for most NASA and NOAA missions was a single large spacecraft platform containing a sophisticated suite of instruments. But the recognition in other areas of space research that cost-effectiveness, flexibility, and robustness may be enhanced by using small spacecraft has raised questions about this philosophy of Earth observation.For example, NASA has already abandoned its original plan for a follow-on series of major platforms in its Earth Observing System. This study finds that small spacecraft can play an important role in Earth observation programs, providing to this field some of the expected benefits that are normally associated with such programs, such as rapid development and lower individual mission cost. It also identifies some of the programmatic and technical challenges associated with a mission composed of small spacecraft, as well as reasons why more traditional, larger platforms might still be preferred. The reasonable conclusion is that a systems-level examination is required to determine the optimum architecture for a given scientific and/or operational objective. The implied new challenge is for NASA and NOAA to find intra- and interagency planning mechanisms that can achieve the most appropriate and cost-effective balance among their various requirements.
Issues in the Integration of Research and Operational Satellite Systems for Climate Research
Part I. Science and Design
Häftad, Engelska, 2000
1 324 kr
Tillfälligt slut
Currently, the Departments of Defense (DOD) and Commerce (DOC) acquire and operate separate polarorbiting environmental satellite systems that collect data needed for military and civil weather forecasting. The National Performance Review (NPR) and subsequent Presidential Decision Directive (PDD), directed the DOD (Air Force) and the DOC (National Oceanic and Atmospheric Administration, NOAA) to establish a converged national weather satellite program that would meet U.S. civil and national security requirements and fulfill international obligations. NASA's Earth Observing System (EOS), and potentially other NASA programs, were included in the converged program to provide new remote sensing and spacecraft technologies that could improve the operational capabilities of the converged system. The program that followed, called the National Polar-orbiting Operational Environmental Satellite System (NPOESS), combined the follow-on to the DOD's Defense Meteorological Satellite Program and the DOC's Polar-orbiting Operational Environmental Satellite (POES) program.The tri-agency Integrated Program Office (IPO) for NPOESS was subsequently established to manage the acquisition and operations of the converged satellite. Issues in the Integration of Research and Operational Satellite Systems for Climate Research analyzes issues related to the integration of EOS and NPOESS, especially as they affect research and monitoring activities related to Earth's climate and whether it is changing.
Issues in the Integration of Research and Operational Satellite Systems for Climate Research
Part II. Implementation
Häftad, Engelska, 2000
1 129 kr
Tillfälligt slut
This is the second of two Space Studies Board reports that address the complex issue of incorporating the needs of climate research into the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS, which has been driven by the imperative of reliably providing short-term weather information, is itself a union of heretofore separate civilian and military programs. It is a marriage of convenience to eliminate needless duplication and reduce cost, one that appears to be working. The same considerations of expediency and economy motivate the present attempts to add to NPOESS the goals of climate research. The technical complexities of combining seemingly disparate requirements are accompanied by the programmatic complexities of forging further connections among three different agencies, with different mandates, cultures, and congressional appropriators. Yet the stakes are very high, and each agency gains significantly by finding ways to cooperate, as do the taxpayers.Beyond cost savings, benefits include the possibility that long-term climate observations will reveal new phenomena of interest to weather forecasters, as happened with the El Nino/Southern Oscillation. Conversely, climate researchers can often make good use of operational data. Necessity is the mother of invention, and the needs of all the parties involved in NPOESS should conspire to foster creative solutions to make this effort work. Although it has often been said that research and operational requirements are incommensurate, this report and the phase one report (Science and Design) accentuate the degree to which they are complementary and could be made compatible. The reports provide guidelines for achieving the desired integration to the mutual benefit of all parties. Although a significant level of commitment will be needed to surmount the very real technical and programmatic impediments, the public interest would be well served by a positive outcome.
637 kr
Skickas
In this new book, a distinguished panel makes recommendations for the nation's programs in astronomy and astrophysics, including a number of new initiatives for observing the universe. With the goal of optimum value, the recommendations address the role of federal research agencies, allocation of funding, training for scientists, competition and collaboration among space facilities, and much more. The book identifies the most pressing science questions and explains how specific efforts, from the Next Generation Space Telescope to theoretical studies, will help reveal the answers. Discussions of how emerging information technologies can help scientists make sense of the wealth of data available are also included. Astronomy has significant impact on science in general as well as on public imagination. The committee discusses how to integrate astronomical discoveries into our education system and our national life. In preparing the New Millennium report, the AASC made use of a series of panel reports that address various aspects of ground- and space-based astronomy and astrophysics. These reports provide in-depth technical detail.Astronomy and Astrophysics in the New Millenium: An Overview summarizes the science goals and recommended initiatives in a short, richly illustrated, non-technical booklet.
809 kr
Tillfälligt slut
In preparing the report, Astronomy and Astrophysics in the New Millenium , the AASC made use of a series of panel reports that address various aspects of ground- and space-based astronomy and astrophysics. These reports provide in-depth technical detail. Astronomy and Astrophysics in the New Millenium: An Overview summarizes the science goals and recommended initiatives in a short, richly illustrated, non-technical booklet.
1 255 kr
Tillfälligt slut
The 1998 Committee on Space Biology and Medicine (CSBM) report A Strategy for Research in Space Biology and Medicine in the New Century assessed the known and potential effects of spaceflight on biological systems in general and on human physiology, behavior, and performance in particular, and recommended directions for research sponsored over the next decade by the National Aeronautics and Space Administration (NASA). The present follow-up report reviews specifically the overall content of the biomedical research programs supported by NASA in order to assess the extent to which current programs are consistent with recommendations of the Strategy report for biomedical research activities. In general, NASA programs concerned with fundamental gravitational biology are not considered here. The committee also notes that this report does not include an evaluation of NASA's response to the Strategy report, which had only recently been released at the initiation of this study.Review of NASA's Biomedical Research Program summarizes the committee's findings from its review of (1) NASA's biomedical research and (2) programmatic issues described in the Strategy report that are relevant to NASA's ability to implement research recommendations.
1 129 kr
Tillfälligt slut
The Committee on Astronomy and Astrophysics (CAA), at its meeting on September 8, 1997, was briefed on the legislative report accompanying the bill to authorize appropriations for fiscal years 1998 and 1999 for the National Science Foundation (NSF). The report raised a number of questions about trends in support for research in astronomy and the overall robustness of the programs providing that support. At its meeting, the CAA heard the views of NSF and the National Aeronautics and Space Administration (NASA) on these issues. In consultation with the Board on Physics and Astronomy, the Space Studies Board, and representatives of NASA and NSF, the committee accepted the task of studying three of the questions raised by the House Science Committee (HSC). It was intended that the results of the study would help guide federal support of basic research for the next decade and serve as analytical input to the new 2000 decadal survey of the Astronomy and Astrophysics Survey Committee (AASC).The study would not offer specific funding recommendations, but rather would provide a background analysis of the alignment between available resources, agency priorities, and the vitality of the basic research program.
751 kr
Tillfälligt slut
In this new book, a distinguished panel makes recommendations for the nation's programs in astronomy and astrophysics, including a number of new initiatives for observing the universe. With the goal of optimum value, the recommendations address the role of federal research agencies, allocation of funding, training for scientists, competition and collaboration among space facilities, and much more. The book identifies the most pressing science questions and explains how specific efforts, from the Next Generation Space Telescope to theoretical studies, will help reveal the answers. Discussions of how emerging information technologies can help scientists make sense of the wealth of data available are also included. Astronomy has significant impact on science in general as well as on public imagination. The committee discusses how to integrate astronomical discoveries into our education system and our national life. In preparing the New Millennium report, the AASC made use of a series of panel reports that address various aspects of ground- and space-based astronomy and astrophysics. These reports provide in-depth technical detail.Astronomy and Astrophysics in the New Millenium: An Overview summarizes the science goals and recommended initiatives in a short, richly illustrated, non-technical booklet.
477 kr
Tillfälligt slut
One of the highest-priority activities in the planetary sciences identified in published reports of the Space Studies Board's Committee on Planetary and Lunar Exploration (COMPLEX) and in reports of other advisory groups is the collection and return of extraterrestrial samples to Earth for study in terrestrial laboratories. In response to recommendations made in such studies, NASA has initiated a vigorous program that will, within the next decade, collect samples from a variety of solar system environments. In particular the Mars Exploration Program is expected to launch spacecraft that are designed to collect samples of martian soil, rocks, and atmosphere and return them to Earth, perhaps as early as 2015. International treaty obligations mandate that NASA conduct such a program in a manner that avoids the cross-contamination of both Earth and Mars. The Space Studies Board's 1997 report Mars Sample Return: Issues and Recommendations examined many of the planetary-protection issues concerning the back contamination of Earth and concluded that, although the probability that martian samples will contain dangerous biota is small, it is not zero.1Steps must be taken to protect Earth against the remote possibility of contamination by life forms that may have evolved on Mars. Similarly, the samples, collected at great expense, must be protected against contamination by terrestrial biota and other matter. Almost certainly, meeting these requirements will entail opening the sample-return container in an appropriate facility on Earth-presumably a BSL-4 laboratory-where testing, biosafety certification, and quarantine of the samples will be carried out before aliquots are released to the scientific community for study in existing laboratory facilities. The nature of the required quarantine facility, and the decisions required for disposition of samples once they are in it, were regarded as issues of sufficient importance and complexity to warrant a study by the Committee on Planetary and Lunar Exploration (COMPLEX) in isolation from other topics. (Previous studies have been much broader, including also consideration of the mission that collects samples on Mars and brings them to Earth, atmospheric entry, sample recovery, and transport to the quarantine facility.)The charge to COMPLEX stated that the central question to be addressed in this study is the following: What are the criteria that must be satisfied before martian samples can be released from a quarantine facility?