The 2011 National Research Council (NRC)1 decadal survey on biological and physical sciences in space,2Recapturing a Future for Space Exploration: Life and Physical Sciences Research for a New Era,3 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 2005,4 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 the National Aeronautics and Space Administration (NASA) as well as for contributing unique science in many fields that can be enabled by access to the spaceflight environment. The important areas of science that are enabled by microgravity and that enable the exploration of space were clearly and extensively articulated in Recapturing a Future for Space Exploration, producing a broad portfolio of science questions and approaches. Thus, Recapturing a Future for Space Exploration presented not only a broad portfolio but also a comprehensive guide for NASA to consider in its rebuilding of the space life and physical sciences program to address exploration imperatives.
As is standard practice following decadal surveys, NASA later requested that the National Academies of Science, Engineering, and Medicine perform a midterm review of NASA’s progress in addressing the decadal survey recommendations. The details of the statement of task for this midterm review by the Committee on a Midterm Assessment of Implementation of the Decadal Survey on Life and Physical Sciences Research at NASA are shown in Appendix A. The statement of task asks for a typical midterm assessment of NASA’s progress against the decadal survey recommendations, then goes on to request a focus on deep space exploration, thus framing much of the midterm assessment as a further ranking of those decadal survey recommendations that enable exploration, in particular, deep space exploration beyond low Earth orbit (LEO).
1 Effective July 1, 2015, the institution is called the National Academies of Sciences, Engineering, and Medicine. References in this report to the National Research Council are used in an historical context identifying programs prior to July 1, 2015.
2 Hereinafter also referred to as “the decadal survey” or “the 2011 decadal survey,” or “the 2011 decadal survey on space life and physical sciences.”
3 National Research Council, 2011, Recapturing a Future for Space Exploration: Life and Physical Sciences Research for a New Era, The National Academies Press, Washington, D.C., https://doi.org/10.17226/13048.
4 NASA, 2004, The Vision for Space Exploration, https://www.nasa.gov/pdf/55583main_vision_space_exploration2.pdf.
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 (SLPSRA) 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. It also has seeded the birth of privately funded research and development in space through the initiation, development, and coordination of the U.S. National Laboratory on the ISS, managed by the Center for the Advancement of Science in Space (CASIS). When considering the role of CASIS, the committee recognized that the U.S. ISS National Laboratory serves the broad need of developing commercial space science for terrestrial applications and need not necessarily address the decadal survey priorities.
The overall result is that the ISS is now running near its present capacity to perform research within current cargo and crew constraints. With NASA looking toward focusing its efforts on deep space exploration, NASA faces important prioritization decisions on the distribution of science research. Indeed, NASA faces a creative tension between developing its exploration goals while servicing the needs of the ISS National Laboratory. Maximizing the science that will enable deep space exploration consistent with the evolving NASA exploration strategy and ISS lifetime, while balancing other ISS science demands, is a challenge. This challenge is, in turn, balanced by the growth of human suborbital space platforms, increased commercial interest in developing LEO, and expansion of relevant ground research capabilities.
NASA’s strategy for exploration has also evolved since the decadal survey. NASA is now focused on Mars as the horizon destination, and since the spring of 2017 has initiated planning for the Deep Space Gateway in cislunar space. This overarching exploration strategy establishes the context for research priorities and programmatic implementation. One key element that remains to be understood is the plan and strategy for the ISS and LEO research beyond 2024 and the current international partnership funding agreements. These unknowns affect how the research necessary for human space exploration will be accomplished.
This summary presents an overview of the mid-decadal assessment of the challenges and progress of the science portfolio since it was presented in Recapturing a Future for Space Exploration. That overview is extended with findings on the status of the research progress and program process within NASA and the extended science community that NASA engages to accomplish the goals of Recapturing a Future for Space Exploration. The overview, findings, and recommendations are organized in this summary in alignment with the statement of task that was developed for this report. The statement of task focuses the report toward the exploration of space given the NASA goal of moving beyond LEO. The statement of task specifically requested that, in addition to the assessment of progress, the committee develop a set of top-priority recommendations dedicated toward exploration. This report describes the assessment of individual science disciplines in more detail and articulates the highest-priority exploration-related science areas to be emphasized in the remaining years of the decade.
NASA’S APPROACH TO AND PROGRESS ON REALIZING DECADAL STRATEGIES, GOALS, AND PRIORITIES
The committee finds that NASA responded to Recapturing a Future for Space Exploration in a strong and positive manner at the programmatic level. As a major response to the programmatic recommendations of the decadal survey, the SLPSRA Division was established as part of NASA’s Human Exploration and Operations Mission Directorate in 2011. “SLPSRA provides administrative oversight of NASA’s Life and Physical Sciences Research, a programmatic home for an integrated research agenda, program leadership and execution under a single management structure and is housed in a NASA directorate organization that understands both the value of science and its potential application in future exploration missions.”5 In support of the relationship between SLPSRA and the decadal survey, the Committee on Biological and Physical Sciences in Space6 was formed as
an activity of the Space Studies Board and the Aeronautics and Space Engineering Board of the National Academies of Sciences, Engineering, and Medicine. Data presented to the committee also demonstrated an increase in budgetary commitment to the science of the decadal survey. In the years following the formation of SLPSRA, the budgets for space life and physical sciences showed signs of stabilizing and improving at the program level and as measured by the levels of science supported and accomplished through engagement of the science community.
The findings and recommendations that follow are identified by the chapter in which they are discussed and their sequential order in that chapter.7
Finding 2-1: NASA addressed the overall strategy of the report Recapturing a Future for Space Exploration: Life and Physical Sciences Research for a New Era in an appropriate and responsive programmatic manner through the formation of SLPSRA. NASA has enhanced community science input related to the decadal survey by developing a strong interaction with the Committee on Biological and Physical Sciences in Space.
Finding 2-2: NASA is supporting the science of the report Recapturing a Future for Space Exploration: Life and Physical Sciences Research for a New Era by modestly increasing the budget and tasks for space life and physical sciences within overall funding constraints and the operational diversification of microgravity science across research platforms.
Recommendation 5-1: NASA should recognize the need for regular requests for research proposals, in order to keep an active external research community available to do exploration-related space life and physical sciences research.
Recommendation 5-9: In light of the resource constraints, NASA should raise the priority of Space Life and Physical Sciences Research and Applications Division research within the International Space Station (ISS) to address the risks and unknowns of human space exploration, particularly given the value of microgravity research for exploration and the urgency resulting from the potential transition of the ISS. These priorities should be directly traceable to the space exploration strategy, linked research priorities, and related technologies.Table 4.1 can be used to initiate this traceability.
Finding 4-1: Several exploration pathways have been proposed by NASA since the 2011 decadal survey, involving the Moon, asteroid missions, Mars, and cislunar space. NASA has also used a separate set of Design Reference Missions to develop its Technology Roadmaps. These frequent exploration strategy changes result in unclear traceability between research investigations and exploration needs.
Recommendation 5-5: NASA should establish and document traceability of the research priorities to its Technology Roadmaps, Design Reference Missions, and exploration strategy.
Recommendation 5-8 : In order to maximize the implementation of decadal survey priorities within its constrained resources, NASA should continue to be mindful of the full range of platforms (including drop towers, aircraft, balloons, suborbital vehicles, and free-flyers) and terrestrial analogs and ground-based laboratories available for decadal survey research.
In assessing the progress of implementation of the decadal survey portfolio, the committee found difficulty in navigating the research tracking within various parts of the Agency that report on research alignments with the decadal survey recommendations. While overall programmatic attention to space life and physical sciences was readily apparent in the many presentations from NASA to the committee, a cumulative alignment or mapping of agency research projects to specific decadal survey recommendations proved problematic.
Finding 2-3: NASA has a diverse approach to the reporting of investigation funding, published results, and experiments that is not fully coordinated among programs and offices, making overall tracking to decadal survey priorities difficult.
Recommendation 5-3: NASA should consider decadal survey priority tracking integration within Agency elements and utilize existing, commercially available, well-known research reporting, and open-science database tools that are in use across the academic research spectrum for accurate, timely, and sustainable information. NASA should also make a determined effort to build on the significant improvements in the International Space Station program for communicating the value of the investigations.
Recommendation 5-6: NASA should further balance communication and reporting efforts across the organization.
EXISTING AND EMERGING CHALLENGES AND OPPORTUNITIES RELATING TO PLANS FOR THE ISS
NASA is moving its exploration focus beyond LEO and into deep space, with cislunar space in the near term and Mars exploration on the horizon. In focusing its exploration agenda on deep space, NASA must contend with multiple and diverse concerns that all compete for resources within the agency. The nuances associated with the move of NASA to a deep space focus are presented in the 2014 NRC report Pathways to Exploration: Rationales and Approaches for a U.S. Program of Human Space Exploration.8 NASA remains very cognizant of the need for space life and physical sciences research to enable deep space exploration and that at least some of that research requires long-term access to microgravity.
Finding 2-4: LEO science research needed for exploration will be required beyond 2024. Extended durations in microgravity, measured in years, will continue to be required to best meet deep space exploration research needs.
Crew time and cargo transfer, particularly downmass, to and from the ISS are critical constraints in the conduct of science on the ISS, and experiment durations need to be pushed toward longer durations in microgravity in order to prepare for deep space transits.
Recommendation 5-2: NASA should continue and increase its efforts to maximize International Space Station (ISS) resource synergy across the ISS National Laboratory, international partners, and the Division of Space Life and Physical Sciences Research and Applications, particularly with regards to crew time availability and research priority on the ISS. Continued efforts to increase cargo and crew transport to and from the ISS should be expedited as much as possible.
The maturation of the ISS capabilities provides the broad research community with a wide range of instrumentation and facilities in the microgravity of LEO. Presentations to the committee indicate that occupancy space within the ISS will be near 95 percent by the end of 2017, with Express Racks full by mid-2018. Similarly, occupancy of the external ISS racks and facilities is also nearly full. As the research capability on the ISS reaches maximum throughput in 2018, it will be important to focus on complete utilization of those facilities rather than developing additional government-funded facilities. The committee also recognizes the recent advancements in privately developed research facilities that can be used for research on the ISS. Budget data presented to the committee indicate that if fewer new facilities were to be developed, significant funds would become available for the conduct of experiments in existing facilities on the ISS.
8 National Research Council, 2014, Pathways to Exploration: Rationales and Approaches for a U.S. Program of Human Space Exploration, The National Academies Press, Washington, D.C.
Finding 2-8: While NASA has worked diligently to enhance ISS research capability since the 2011 decadal survey, the potential 2024 transition era of U.S. participation in the ISS may call for a change of strategy with respect to ISS facilities development, including use of privately developed research facilities.
Recommendation 5-7: NASA should direct an increasingly higher priority toward the conduct of science within existing International Space Station (ISS) hardware and research capabilities. Utilization of existing, including privately developed, ISS facilities should be maximized in recognition of the current funding limits, the ISS transition timeline, and the need for high-priority microgravity research.
NASA has appropriately initiated an internal activity to develop and assess various options for the ISS beyond 2024. At the time of this report, no conclusions have been drawn. NASA did provide the committee with a presentation on the status of this activity. To identify and assess potential ISS strategy options, NASA has developed a list of key considerations. These considerations include a long-term U.S. presence in LEO that is characterized by leadership of international partnerships, continuing support for commercial space activities in LEO, and an ecosystem that fosters ongoing deep space exploration objectives beyond LEO while continuing research and development for fundamental science and technology. The overarching consideration is affordability and sustainability.
Recommendation 5-10: It is essential that NASA as quickly as possible develop an International Space Station post-2024 strategy. This development factors strongly in the overall exploration strategy, space life and physical sciences research priorities, and resource allocation in terms of crew time, cargo delivery, and funding. This post-2024 strategy should address clear cost allocation among the various research activities and partners.
CHALLENGES AND OPPORTUNITIES OF A MULTISPONSOR SCIENCE PROCUREMENT APPROACH
The interests of the international participants and the ISS National Laboratory are all coordinated into a vast orbital enterprise that has many investors, constituents, and overseers. In particular, the emergence of CASIS as the manager of the ISS National Laboratory has brought major, non-exploration visibility and demands to the ISS. The committee considers the positive growth of research interest in the ISS to be a major accomplishment of both NASA and CASIS. Yet as NASA seeks to maximize space life and physical science on the ISS toward meeting its exploration needs, it must balance the challenges of managing that need with the many non-exploration demands on the ISS. This places at risk the progress of space life and physical sciences in support of exploration.
Finding 2-5: NASA coordination with ISS National Laboratory continues to develop in a laudable manner. However, as NASA meets the challenges of ISS National Laboratory implementation, its own exploration priorities face increased pressure to garner ISS research resources, such as crew time, cargo delivery, and ISS experiment prioritization. This pressure leaves NASA exploration research priorities at risk of not being met.
NASA openly seeks to make space accessible to research interests in other agencies; for example, its Science Mission Directorate has long been active in this regard. For the Human Exploration and Operations Mission Directorate (HEOMD) and SLPSRA, engaging other agencies in research is a relatively new venture. It has opened the realm of microgravity research, especially on the ISS, to other agencies. While this engagement is welcome and positive, it remains unlikely that other agencies will participate directly in the science of the exploration imperatives within NASA. Rather, other agencies will utilize NASA facilities to support their own research agendas.
Finding 2-6: NASA has initiated relationships and improved efforts to work with other U.S. agencies and nongovernmental institutions to explore the value of microgravity in science. The committee was unable to identify any other federal agency with a programmatic reason to absorb the full costs of developing and conducting experiments on the ISS, even in the face of rising interest in microgravity research.
Finding 2-7: As NASA’s ISS strategy evolves for the timeframe beyond the current 2024 commitments, there is a need for clear and objective analyses of all costs necessary to support research. Cost elements (e.g., launch, personnel, operations, facility maintenance) for ISS research projects and CASIS activities are important factors in the assessment of research activities and for determining appropriate partner funding levels.
Recommendation 5-4: Relationships with the National Institutes of Health, the National Institute of Standards and Technology, the National Science Foundation, the Department of Defense, the Department of Energy, and other agencies should be strengthened to better address the decadal survey and midterm review identified research priorities, especially exploration priorities. NASA should consider negotiation with the Center for the Advancement of Science in Space regarding International Space Station research allocations to better address NASA’s exploration priorities.
ACTIONS TO BE TAKEN TO OPTIMIZE SCIENCE VALUE TO EXPLORATION, AND GUIDANCE FOR IMPLEMENTATION
As NASA has developed its deep space exploration plans, there has been tremendous refocusing on the science needed to best enable that exploration. The committee heard many presentations on the progress that has been made in space life and physical sciences since the 2011 decadal survey. The committee also heard from both NASA and the external science community that a large amount of science remains to be done to best support the move to deep space. In particular, the committee recognized the rather simple facts that all deep space mission plans absolutely require long periods of time in microgravity and will be outside the radiation protection of Earth’s magnetosphere. There are no plans in any design reference missions to include large-scale induced gravity within the transit vehicle. If microgravity remains the operational environment for exploration transit, then humans and their attendant biological and physical support systems must function adequately and independently in microgravity for durations up to years. Yet the number of long-term space biology experiments on orbit has been minimal, and many physical systems currently employed on the ISS are known to require extensive maintenance. Therefore, understanding the fundamentals of long-term microgravity exposure for life and physical sciences is a top priority. Similarly, radiation, specifically operational exposure to actual deep space radiation, remains a major identified risk to humans and a large unknown risk to biological and physical systems in deep space. With the totality of human exploration experience beyond LEO restricted to the Apollo era, and the limited number of long-duration experiments conducted to date on the ISS, the need for microgravity and radiation science research is as strong now as ever.
Finding 3-1: Deep space exploration will take place for long periods of time in a microgravity and high-radiation environment; no large-scale induced gravity on the vehicle or station is foreseen with the current design reference missions, and the only shielding expected for radiation damage is that which is available on the space vehicle. Therefore, a fundamental understanding of both microgravity and radiation effects on biological and physical systems is essential for operational success and appropriate protection of astronauts.
Recommendation 3-1: As NASA continues to develop deep space mission scenarios involving long durations in microgravity, understanding the direct and interactive effects of radiation, microgravity, and small habitats on human biology and on the performance of biological and physical systems in space over long durations will need to have high priority in NASA science plans. NASA should also improve the coordination among the science research and engineering teams to better address the integrated effects in the design of the exploration elements and systems.
Finding 4-2: The current funding levels are insufficient to fully address the significant unknowns and risks of human exploration beyond LEO. Fundamental understanding of human health and behavior risks in microgravity, combined with fundamental microgravity physics and materials, in an integrated manner,
is essential to extending the human neighborhood beyond LEO. Significant risks remain, particularly in understanding the radiation environment and its effects, environmental control and life support, human behavior, and protecting long-term crew health with integrated countermeasures. These risks are best addressed in the respective disciplines and in an increasingly integrated fashion.
Finding 4-3: NASA has pursued means to improve internal cross-organizational efforts across the research and technology development landscape, based on the linkages with the Technology Roadmaps.
Recommendation 5-11: NASA should aggressively lead in the 46 research priorities for deep space exploration identified in Table 4.1 of this midterm report to provide as much “pull” as possible for exploration enhancement using space life and physical sciences. NASA should, for example, lead in the development of microgravity-adapted biological and physical systems, making maximum use of all available platforms, including the International Space Station, specifically for the science behind the design and implementation of microgravity-optimized operation.
To help guide maximization of science return for exploration, especially considering the remaining available ISS time, the committee identified and ranked from among the high-priority recommendations in the decadal survey those exploration-enabling research priorities it deemed most critical for NASA to conduct. These rankings are summarized in Table 4.1. These rankings are accompanied by discipline science narratives that provide the underpinnings for each priority. Also presented are the criteria and considerations used for selecting and ranking the priorities.
The decadal surveys presented a total of 65 specific high-priority recommendations over 7 discipline areas. Using the criteria of the decadal survey that apply to deep space exploration, the committee determined that 46 of those recommendations were considered by the decadal survey committee to be the highest-priority recommendations related to exploration. The committee then ranked these 46 recommendations to produce Table 4.1, showing the 24 highest-, 12 higher-, and 10 high-priority recommendations targeted at exploration needs. The highest-priority recommendations recognize the need for long-term microgravity experiments, especially experiments that address interfaces between biological and physical systems that make use of the remaining time on the ISS. These recommendations also serve as a guide for initial deep space exploration planning, such as science that may be conducted on the Deep Space Gateway or similar exploration vehicles should they be implemented, where deep space radiation can be studied in its confluence with microgravity and all the issues assembled within a deep space transit vehicular system.
The committee wishes to highlight the tension between the “enabling” research and the research “enabled by” the unique microgravity environment. While recognizing the funding constraints, and therefore the need for NASA to prioritize microgravity research, the committee also recognizes the value of fundamental research such as the Alpha Magnetic Spectrometer and experiments utilizing the Cold Atom Lab. These fundamental science efforts can only be performed in a long-duration microgravity environment.
Recommendation 5-12: The committee recommends that a cautious approach be used when shifting the NASA research portfolio more toward those types of experiments necessary for deep space exploration, so as to maintain the benefits of important basic experiments, especially those uniquely enabled by International Space Station microgravity and already in progress, which may in the long term have the potential for major impacts in fundamental physical science.