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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap Executive Summary ABSTRACT The National Aeronautics and Space Administration’s (NASA’s) Bioastronautics Roadmap (BR) is “the framework used to identify and assess the risks of crew exposure to the hazardous environments of space.” The BR was created to facilitate and support the successful accomplishment of the three Design Reference Missions: a one-year mission to the International Space Station, a month-long stay on the lunar surface, and a 30-month round-trip journey to Mars. The contents of the document are the identified risks, the research and technology questions associated with these risks, and the desired outcomes. In 2003, NASA asked the National Academies to conduct a comprehensive assessment of the BR and identify the unique challenges in accomplishing its goals. An ad hoc committee examined the content of the BR, the process used in developing and updating it, and the context in which the BR was developed and will be used. The committee concluded that the current version of the BR is a useful first step, but it will not be adequate to achieve its stated goals unless the recommendations provided by the committee are incorporated into the document and into the thinking and actions of NASA’s management. Four of the committee’s 16 recommendations were labeled “principal,” indicating their crucial role in a risk mitigation plan. These are (1) accelerate countermeasure and technology development; (2) establish a safe radiation exposure level for all relevant
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap risks; (3) incorporate quality-of-evidence measures, represent risk severity separately from the state of the mitigation strategy or countermeasure, and use standard uncertainty analysis techniques to quantify risk uncertainty; and (4) ensure that the BR is a dynamic and current database. The committee identified both overarching and specific issues in need of attention in the BR content. Overarching issues involve the impact of various time factors on risk, the interactions among risks, and the need to create two new cross-cutting categories of risk: “Human Systems Integration” and “Food and Nutrition.” Specific issues include the need to (1) validate current and future crew selection criteria; (2) group behavioral health risks into categories based on clinical outcomes and address issues of human sexuality in long-duration missions; (3) use actuarial data to estimate the likelihood of intrinsic health alterations as part of the selection criteria for the Mars mission crew; and (4) quantitatively evaluate mental and physical health risks affecting crew health and mission success. The committee concurred with NASA regarding the establishment of an independent health and medical authority to enhance the BR process and recommended that NASA (1) add human performance failure due to organizational and cultural factors as a new risk; (2) conduct periodic assessment of additional risks from lack of resources and use this to make decisions about research support; (3) use Bayesian sequential trials approach and hierarchical random or fixed effect methods to address the small sample size resulting from limited opportunities for space flight; and (4) reframe risks as either health or technology related, in order to address issues within the BR context. INTRODUCTION Extending the spatial and temporal boundaries of human space flight are important goals for the nation and for the National Aeronautics and Space Administration (NASA). However, human space flight remains an endeavor with substantial risks, and these risks must be identified, managed, and mitigated appropriately to achieve the nation’s goals in space. The Bioastronautics Roadmap (hereafter referred to as the BR) is described by NASA as “the framework used to identify and assess the risks of crew exposure to the hazardous environments of space” (NASA, 2005). The BR
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap also “guides the prioritized research and technology development that, coupled with operational space medicine, will inform the development of medical standards and policies, the specifications of requirements for the human system, and the implementation of medical operations.” The BR was created to facilitate and support the successful accomplishment of the three Design Reference Missions described in the President’s space initiative of January 14, 2004 (White House, 2004), specifically, a one-year mission to the International Space Station (ISS), a month-long stay on the lunar surface, and a 30-month round-trip journey to Mars. The stated goal of the BR is “to reduce risk through effective and efficient mitigation solutions developed from a focused research and technology development strategy” (NASA, 2005). The contents of the document are the identified risks; the research and technology questions associated with these risks; and the deliverables—or the desired outcomes or solutions—related to these questions. Major processes of the BR include risk identification and risk assessment. The context in which these risks are identified includes the mission requirements for the three Design Reference Missions as well as the organization and systems within NASA and the external organizations and systems that govern NASA (e.g., executive and legislative branches of government, federal budget). The February 2005 version of the BR used by the committee for its review, in a traditional document format, is enclosed as a CD in the cover of this report. Both the baseline document and the interactive version that relates to specific risks and Design Reference Missions are available on-line at http://bioastroroadmap.nasa.gov. CHARGE TO THE COMMITTEE In 2003, prior to the unveiling of the President’s space exploration vision, NASA asked the Institute of Medicine (IOM), in collaboration with the Division on Engineering and Physical Sciences of the National Academies, to conduct a review of the BR. Specifically, NASA asked the committee to (1) conduct a comprehensive assessment and report of the strengths and weaknesses of the content and processes of the BR as applied to the missions described in the President’s exploration initiative and (2) identify the unique challenges for accomplishing its goals and objectives. Specific questions for the committee to answer included—but were not limited to—the following:
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap How can the BR better capture and describe the critical risks and key research and technology issues for risk reduction and management so as to provide a framework for informed decisions regarding resource allocation? Does the BR use an appropriate method of risk assessment and expression of risk assessment? Does it adequately communicate the methods underlying risk assessment and the resulting activities for different mission scenarios? How well does the BR address different types of risk (e.g., health, engineering) and their impact? Are the categories of critical research issues and the metrics used to analyze them appropriate (risk assessment and characterization, mechanistic/process research, countermeasure development, and medical diagnosis and treatment)? Are efficiency and technology issues properly and adequately addressed? Responding to NASA’s request, the Committee on Review of NASA’s Bioastronautics Roadmap approached its charge by focusing on the three general categories of issues in the content of the BR (Chapter 2); the process involved in the development, updating, and utilization of the BR (Chapter 3); and the context within which the BR is framed and expected to be used (Chapter 4). The committee held eight meetings, most of which included a data-gathering session where testimony from NASA officials and space science experts was heard. In addition, several committee members met with NASA officials and other experts to gather information. The committee’s conclusions and recommendations in this report are based on published sources of information as well as on the committee’s experience and expertise in the diverse fields included in the BR. OVERALL ASSESSMENT OF THE BIOASTRONAUTICS ROADMAP The committee’s comments focus on areas in which improvement seems necessary and most valuable, but the committee wishes to emphasize that the present document demonstrates that NASA has considered many of the key factors carefully and is handling many aspects of this complex challenge appropriately. The committee was impressed by the progress that appeared in the BR during the course of this review. The reader should not
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap lose sight of these many positives when reading the following analyses, conclusions, and recommendations, which focus on opportunities for improvement. The current version of the BR is a useful first step, but it will not be adequate to achieve its stated goals unless the recommendations provided here are incorporated into the document and into the thinking and actions of NASA management. The BR must constantly be updated and maintained, the resulting action plans that flow from the BR must be supported by adequate allocation of resources both to NASA and within NASA, and the action plans must be implemented fully. If these criteria are met, the committee believes that the BR will be an effective mechanism to mitigate risks to human health and thus contribute to ensure mission success during extended space flight. PRINCIPAL FINDINGS AND RECOMMENDATIONS The committee concludes that all of its recommendations should be implemented in order to achieve the goals of the BR. However, the committee is convinced that the following four principal recommendations must be applied if the BR is to be an effective approach to risk identification and risk reduction associated with the Design Reference Missions. Status of Readiness Levels A variety of deliverable products result from the BR. Progress in these areas is gauged by establishing “readiness levels” that delineate the level of maturity of countermeasures or technologies to support the human system in space. Currently, the BR proposes 183 projected deliverables. In the context of the BR, these deliverables constitute the risk mitigation plan for the human system. The BR emphasizes that “roadmap activities must focus on operational issues and solutions to operational problems to support an outcome-oriented approach.” Thus, “bioastronautics research is focusing on deliverables at a readiness level of 4 or greater” (NASA, 2005, p, 17). However, more than half (53%) of the deliverables proposed in the BR rank below the stage 4 level of readiness and thus below the threshold for priority in bioastronautics research consideration. The committee concludes that this emphasis on an applied research agenda for NASA bioastronautics is not without significant consequences and risks, especially given the relatively immature status of current countermeasure development. Further, the committee finds that the majority of projected BR countermeasures,
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap mitigations, or other deliverables are in a nascent state of readiness (i.e., below the threshold for prioritization in bioastronautics research) and that the state of countermeasure development significantly lags the need. Current resources are unlikely to be sufficient to complete the BR mitigation plan in a time frame that enables the exploration class missions envisioned by NASA. Recommendation 2.3—Accelerate Countermeasure and Technology Development The committee recommends that NASA initiate an aggressive program, including the use of animal models, analog environments, and space flight, to significantly accelerate the progress of all Countermeasure Readiness Levels and Technology Readiness Levels that are essential to support the proposed exploration agenda. Countermeasures and technologies at an undefined or low state of readiness (the majority of the current portfolio) should receive renewed attention. The committee notes further that failure to do so will jeopardize the exploration program outlined in the President’s vision for exploration of January 2004. Radiation Effects—Establishing Risk-Specific Radiation Exposure Levels The committee concludes that radiation effects are given ample weight in the BR and concurs with NASA’s assessment that the duration of the mission and the distance from Earth will determine the amount and type of radiation exposure and the required shielding for both the vehicle and the protective wear for extravehicular activity (EVA), with the associated weight and design implications. However, the conventional rule of thumb for terrestrial radiation protection—that is, that protection against late radiation effects such as increased cancer risk will also protect against acute radiation effects—may not hold for high-energy radiation (HZE) from galactic cosmic rays, particularly regarding central nervous system (CNS) impairment. As with the other components of the BR, it will be essential to follow the developments in both space and terrestrial biological research as well as shielding technology to ensure crew health and safety for longer-duration, higher-radiation-exposure exploratory missions.
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap Recommendation 2.9—Establish a Safe Radiation Exposure Level for All Relevant Risks The committee recommends that a safe radiation exposure level be established by NASA for each relevant risk, based on projected flight duration and distance from Earth, and that the technology to keep the level of exposure below that limit be ensured. Inherent in this recommendation and consistent with Recommendation 2.3, the committee concludes that NASA must conduct further research to clarify the extent to which protracted or low-dose HZE radiation exposure might contribute to mission-damaging CNS effects. Risk Assessment The committee agrees that NASA’s decision to draw on expert opinion in identifying and ranking risks is a reasonable strategy. However, the committee believes that there are weaknesses in the current risk assessment process related to (1) lack of information regarding the quality of evidence that informs risk assessment, (2) the obscuring of risk that results from “lumping” both the risk and its associated mitigation into a single value, and (3) lack of a quantitative measurement of uncertainty related to the risk. These areas can, and should, be enhanced. Risk assessment should primarily be evidence-based wherever possible, and where evidence does not exist, research should be directed to acquiring the evidence needed. Rating the quality of each published source of information should be a component of the BR. The committee also believes that disaggregation of risk from mitigation of risk is important because (1) aggregated risk values obscure the risk itself and can lead to false confidence or concern, depending on the status of countermeasure or technology development; (2) approaches that mitigate one risk may have a positive or negative impact on other risks or mitigations; and (3) changes in systems may have a positive or negative impact on mitigations. Failure to track risk separately from risk mitigation could well lead to failure to focus on the inherent relationships among risks and mitigations. In addition, the determination of risk always involves an element of uncertainty. The committee concludes that the current printed and on-line versions of the BR do not include any expression of uncertainty in terms of risk estimates, reported confidence intervals, or narrative discussion.
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap Recommendations 3.1, 3.2, and 3.3—Incorporate Quality-of-Evidence Measures, Represent Risk Severity Separately from the State of the Mitigation Strategy or Countermeasure, and Use Standard Uncertainty Analysis Techniques to Quantify Risk Uncertainty The committee recommends that NASA (1) determine, and incorporate into the BR, measures of the quality of the evidence that form the basis for defining risks and the assessments associated with each risk; (2) structure the BR to represent separately the severity and likelihood of each risk and the state of the mitigation strategy or countermeasures associated with each risk; and (3) whenever possible, restructure the BR to include a quantification of the uncertainty of risks using standard uncertainty analysis techniques (e.g., frequentist, Bayesian, or possibility theory and approximate reasoning) that will provide uncertainty distributions or ranges in addition to point estimates. This will help contribute to the subsequent definition of operating bands. Risk Communication and Keeping the BR Current The way in which risk-related information is represented in the BR and communicated to users is important to its overall effectiveness as a program management tool. One widely used format for representing risks not currently incorporated into the BR is the NASA-wide Continuous Risk Management Program, and the committee encourages its continued use because it is widely recognized and understood throughout NASA. The committee believes that the BR is better thought of and designed as a dynamic database of information relative to risk definition and assessment, from which a document or set of alternative documents can be derived at any time and incorporated into a risk management program. The web-based on-line version of the BR is an important step in this direction. It is fundamentally important that configuration control methods be established and implemented to keep the BR up-to-date as new knowledge and technologies develop. This process can be facilitated by identifying an “owner and manager” within NASA for each set of related BR risks and establishing a regular review cycle that should occur not less than once a year. Where there is a desire to combine published research data with “expert opinion” from stakeholders, methods such as Bayesian updating and elicitation of expert opinion are available.
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap Recommendations 3.4 and 3.5—Ensure That the BR Is a Dynamic and Current Database That Enhances Communication and Conveys Information Effectively To enhance effective communication of the content of the BR, the committee recommends that the BR be designed and utilized as a dynamic database of information relative to risk definition and assessment, from which a document or set of alternative documents can be derived at any time and incorporated into a risk management program. The references currently cited in the BR must be updated to reflect more recent research on both risk identification and countermeasure development. Moreover, a mechanism should be established for the ongoing review of the current best evidence contained in the research literature, and methods should be developed to integrate new findings from the literature with the expert opinion of key stakeholders, including those from operations and the research community. The remaining recommendations focus on either general principles (overarching issues) or specific issues that need to be addressed in the BR. The committee believes that all of these are equally important and should be implemented; thus, they are not presented in order of priority but rather are grouped by the three principal themes of content, process, and context. OVERARCHING ISSUES IN THE BR CONTENT Overarching issues are those factors that, in the committee’s view, deserve wide review and application throughout the current BR and future revisions of the BR. They should be viewed as strategic approaches to the revision and management of the BR. The Time Factor and Its Impact on Risk Recommendation 2.1—Label Risks by Relevance to Operational Requirements and Temporal Urgency The committee recommends that risk assessment and mitigation (technology or countermeasure development) in the BR be enhanced by labeling risks according to their relevance to operational requirements and to temporal urgency.
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap Interactions Among Risks Recommendation 2.2—Define, Quantify, and Mitigate Interactions Among Risks The committee recommends that greater effort be devoted to identifying and explaining the interrelations among risks and risk mitigations that are grouped within and across the cross-cutting categories in the BR. Creating the Cross-Cutting Categories “Human Systems Integration” and “Food and Nutrition” Recommendations 2.4 and 2.5—Create Two New Cross-Cutting Categories: Human Systems Integration and Food and Nutrition The committee recommends that NASA create two new cross-cutting categories in the BR: 1. A cross-cutting category that spans the two existing categories of “Behavioral Health and Performance” and “Space Human Factors Engineering” risks listed currently in the area of Advanced Human Support Technologies. This new category should be labeled “Human Systems Integration,” consistent with the terminology currently in use by the U.S. Department of Defense (2004) and the Human Systems Integration in NASA Headquarters. 2. The cross-cutting area “Nutrition” should be renamed and expanded to “Food and Nutrition” to more fully encompass the concepts of dietary needs for space flight and emphasize the relationships between nutrition and food technology. Further, the committee recommends that the impact of inadequate food and nutrition on processes related to mental and physical health risks and maintenance of the space environment and life support systems be defined from the standpoints of food safety, quality, and quantity, and interventions proposed if problems occur. SPECIFIC ISSUES Specific issues are those areas that deserve focused attention and refinement in the BR to more effectively accomplish its goals as a management
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap tool. They should be viewed as tactics for the document, whereas the overall issues should be viewed as strategies. Recommendations Related to Specific Issues in the BR Content Recommendation 2.6—Validate Current and Future Crew Selection Criteria The committee recommends that the Astronaut Office and representative flight surgeons be consulted regarding the crew selection process in order to place greater emphasis on the roles of crew compatibility and team performance in overall mission success. Recommendations 2.7 and 2.8—Group Behavioral Health Risks into Categories Based on Clinical Outcomes, and Address Issues of Human Sexuality in Long-Duration Missions The committee recommends that behavioral health risks within the proposed new cross-cutting category of Human Systems Integration be grouped into categories based on clinical outcomes such as interpersonal conflict, affect regulation, decrements in cognitive performance, mood disorders, and sleep disorders, rather than categories such as psychosocial, neurobehavioral, cognitive, and circadian rhythms, and that the interrelations between these categories be delineated clearly. In addition, issues of human sexuality should be addressed in the BR in relation to long-duration missions such as the proposed Mars Design Reference Mission. Recommendation 2.10—Use Actuarial Data to Estimate the Likelihood of Intrinsic Health Alterations as Part of the Selection Criteria for the Mars Mission Crew The committee recommends that, wherever possible, NASA use actuarial data to estimate and/or model the likelihood of intrinsic health alterations for crew who will be part of the Mars mission. Utilization of this information as part of the selection criteria for astronauts should be considered. After intrinsic health risks are estimated, NASA should then estimate and/or model the contribution of the space environment and life support system malfunction to increased risk.
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap Recommendation 2.11—Develop a System for Quantitative Evaluation of Mental and Physical Health Risks Affecting Crew Health and Mission Success The committee recommends that a system be developed for quantitatively evaluating the mental and physical health risks that could affect mission success and crew health and that priorities for countermeasure development (i.e., definitive treatment vs. palliation) be established for the most likely conditions to be encountered during each reference mission. A panel of outstanding medical clinicians should be used to assist NASA medical operations staff in characterizing the likelihood, importance, and “treatability” of each condition. Recommendations Related to Specific Issues in the BR Process Recommendation 3.6—Establish an Independent Health and Medical Authority The committee endorses the principle that critical decisions regarding safety and health should be made by an authority that is independent of programmatic costs and schedules. Given the importance and complexity of health and human safety issues, the committee acknowledges and endorses the creation of the Independent Health and Medical Authority (IHMA), analogous to the Independent Technical Authority, and recommends that the IHMA be given responsibility, authority, and accountability for the health and safety decisions that relate to risks identified in the BR. Recommendations Related to Specific Issues in the BR Context Recommendation 4.1—Add New Risk: Human Performance Failure Due to Organizational and Cultural Factors The committee recommends that an additional risk labeled “human performance failure due to organizational and cultural factors” be added to the BR. It may prove optimal to track this risk in a manner differently from the other risks in the BR (e.g., annual analyses of organizational and cultural risk in a separate report, use of an external standing panel to discuss this issue regularly). The committee’s intent is that a
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap risk-focused analysis of organizational and cultural issues become a visible part of the BR process. Recommendation 4.2—Conduct Periodic Assessment of Additional Risks from Lack of Resources and Use This to Make Decisions About Microgravity and Behavioral Research Support The committee recommends that NASA perform regular, detailed assessments of the additional risks to the conduct of the President’s 2004 vision for space exploration posed by the lack of available resources to fully address the issues posed in the BR. This assessment should then be used to make early strategic decisions regarding issues such as, but not limited to, the following: 1. How to provide support for a microgravity research platform that will have the resources (crew time, up-mass, facilities, and power) for the large amount of work necessary to validate countermeasures; achieve Technology Readiness Level 7 for life support systems sufficiently early in the design phase to allow their integration into the overall vehicle; and demonstrate the utility of medical procedures in microgravity. 2. How to support the extensive behavioral research program that would be necessary to validate processes or countermeasures such as select-in–select-out criteria (both for individual crew members and for a composite crew), issues related to cultural diversity, crew interactions, and isolation or stress-induced hazards. These issues may well require long lead times to study adequately. Recommendation 4.3—Use Bayesian Sequential Trials Approach and Hierarchical Random or Fixed Effects Methods to Address the Small Sample Size Drawing on the findings of the Institute of Medicine report Small Clinical Trials: Issues and Challenges (IOM, 2001), the committee recommends the use of pooled data from Bayesian sequential trials techniques and hierarchical random or fixed effects methods to compensate for the small sample sizes associated with individual flights.
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap Recommendation 4.4—Reframe Risks as Either Health or Technology Related The committee recommends that the current definition of risk be altered to clearly identify at least two types of risks: (1) health and medical risk, defined as the conditional probability of an adverse event to the human system (i.e., crew health or medical event) resulting from exposure to the space flight environment, and (2) engineering technology and system performance risk, defined as the conditional probability of an adverse event resulting from the space flight supersystem that affects crew health or mission success. Box ES-1 contains a summary of the report’s recommendations. BOX ES-1 SUMMARY OF RECOMMENDATIONS Principal Recommendations 2.3 Accelerate Countermeasure and Technology Development 2.9 Establish a Safe Radiation Exposure Level for All Relevant Risks 3.1, 3.2, 3.3 Incorporate Quality-of-Evidence Measures, Represent Risk Severity Separately from the State of the Mitigation Strategy or Countermeasure, and Use Standard Uncertainty Analysis Techniques to Quantify Risk Uncertainty 3.4, 3.5 Ensure That the BR Is a Dynamic and Current Database That Enhances Communication and Conveys Information Effectively Recommendations on Overarching Issues in the BR Content 2.1 Label Risks by Relevance to Operational Requirements and Temporal Urgency 2.2 Define, Quantify, and Mitigate Interactions Among Risks 2.4, 2.5 Create Two New Cross-Cutting Categories: Human Systems Integration and Food and Nutrition
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A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA’s Bioastronautics Roadmap Recommendations on Specific Issues in the BR Content 2.6 Validate Current and Future Crew Selection Criteria 2.7, 2.8 Group Behavioral Health Risks into Categories Based on Clinical Outcomes, and Address Issues of Human Sexuality in Long-Duration Missions 2.10 Use Actuarial Data to Estimate the Likelihood of Intrinsic Health Alterations as Part of the Selection Criteria for the Mars Mission Crew 2.11 Develop a System for Quantitative Evaluation of Mental and Physical Health Risks Affecting Crew Health and Mission Success Recommendations on Specific Issues in the BR Process 3.6 Establish an Independent Health and Medical Authority Recommendations on Specific Issues in the BR Context 4.1 Add New Risk: Human Performance Failure Due to Organizational and Cultural Factors 4.2 Conduct Periodic Assessment of Additional Risks from Lack of Resources and Use This to Make Decisions About Microgravity and Behavioral Research Support 4.3 Use Bayesian Sequential Trials Approach and Hierarchical Random or Fixed Effects Methods to Address the Small Sample Size 4.4 Reframe Risks as Either Health or Technology Related REFERENCES IOM (Institute of Medicine). 2001. Small Clinical Trials: Issues and Challenges. Washington, DC: National Academy Press. NASA (National Aeronautics and Space Administration). 2005. Bioastronautics Roadmap—a risk reduction strategy for human space exploration. On-line [available: http://ston.jsc.nasa.gov/collections/TRS/-tecjre[Sp-2005-6113.pdf]. Accessed 1/6/2006. U.S. DOD (U.S. Department of Defense). 2004. Defense Acquisition Guidebook. DoDD 5000.1 On-line [available: http://akss.dau.mil/dag]. White House. 2004. President Bush announces new vision for space exploration program. Remarks by the President on U.S. space policy. On-line [available: http://www.whitehouse.gov/news/releases/2004/01/20040114-3.html]. Accessed 5/26/05.
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