The Committee for the Decadal Survey on Biological and Physical Sciences in Space was tasked in this study to review the next 10 years’ scientific challenges and opportunities for the U.S. space program as it advances its tradition of exploration and discovery in microgravity environments. The committee was instructed in its task to disregard considering specific budgetary recommendations and instead to focus on one enormously challenging question: What are the key scientific challenges that life and physical sciences research in space must address in the next 10 years? This review, or decadal survey, takes place in the context of the many remarkable achievements of the National Aeronautics and Space Administration (NASA) in exploring and studying space during the past 40 years. However, NASA’s continued preeminence in this endeavor cannot be assumed, because other nations have both a keen interest, and the intent to make their own mark, in space. The European Space Agency, Russian Federal Space Agency, Japanese Aerospace Exploration Agency, Canadian Space Agency, and Chinese National Space Administration are among the many international agencies now working to make substantial progress in exploration. Furthermore, the continued leadership of the United States in space activities depends on clear goals for the research program and a consistent level of fiscal support for implementation of such programs.1
These are not new issues. The history of terrestrial exploration was also marked by a tension between nations’ competition versus cooperation, by the financial costs of exploration versus pressing local economic needs, and by governmental decisions that either facilitated or hindered exploration. What is also evident from history is that exploration is inherently costly, dangerous, and unpredictable, requiring nations to make long-term fiscal and scientific investments in activities whose benefits are frequently unimagined or unrecognized for many years.
The responsibility for conducting a decadal survey and providing recommendations, priorities, and timetables was assumed by an NRC-appointed committee that subsequently appointed expert chairs and members to the following advisory panels:
• Animal and Human Biology Panel,
• Applied Physical Sciences Panel,
• Fundamental Physical Sciences Panel,
• Human Behavior and Mental Health Panel,
• Integrative and Translational Research for Human Systems Panel,
• Plant and Microbial Biology Panel, and
• Translation to Space Exploration Systems Panel.
After appointment, members received documents and hours of briefings from NASA, as well as from commercial and academic authorities on biological and physical science matters, pertaining to previous utilization of National Academies reports; NASA’s research facilities, capabilities, procedures, and needs for exploration; lunar exploration and habitation; the International Space Station (ISS) as a platform for physical and biological research; the potential for and feasibility of commercial platforms; and research findings from space which, when combined with the extensive literature on microgravity and partial-gravity research, became the basis for recommendations, priorities, and timetables.
The report is divided into 13 chapters that summarize the deliberations of the committee and input of its seven panels of experts. Information, perspectives, and advice were obtained from the general public and experts in the field through town halls at professional society meetings and from solicited white papers from informed and concerned scientists. Various representatives of past and current NASA programs, experts from a range of disciplines, and speakers from private companies that are increasingly involved in space exploration all provided briefings to the panels and the committee.
Before presenting the findings of this decadal survey, the committee considered lessons learned from humankind’s long experience with exploration and with the challenges of progressively broadening the frontiers of the known world. Throughout human history, exploration has driven some of our most inspiring achievements and profound discoveries. By discovering that the stars at night were distant points in a three-dimensional space, humans realized that Earth is not flat and that it is not the center of the universe. We gained the courage to travel over great distances and discovered new lands, new materials, and new resources. Moreover, the process of exploration resulted in new ways of thinking about the world and ourselves. For example, the quest to explore exacerbated the risk of incurring serious diseases, such as scurvy, which led to new ways of understanding health and illness (e.g., the importance of nutrition). Exploration inspired competition and government backing to develop new technologies, such as methods for accurate navigation (e.g., John Harrison’s time pieces to derive accurate measures of longitude). The drive to explore continues today, and the key frontier of the future is space.
Multiple and varied platforms have and will continue to contribute to the acquisition of knowledge and to the enhancement of exploration. The ISS will play a pivotal role as a dedicated experimental laboratory for biological and physical research. Additionally, the promise that commercial transportation may one day provide operational platforms for microgravity and partial-gravity research should not be ignored.
Many believe that humanity is destined for a future in space. However, even with all of the resources of Earth, the enormous challenges of space voyages will not be overcome unless guided by significantly enhanced scientific research. In this context, it is interesting to review lessons learned from the history of Earth-based exploration.
Exploration has always been shaped by scientific and engineering research confronting new challenges. It took many years to learn how to deal with the destruction of wooden-hulled ships by Toredo worms; it took more years yet to learn that ships were jeopardized by galvanic interactions between the copper sheathing of hulls, which was effective against the worms, and ships’ iron bolts. It is likely that similar unanticipated problems and solutions will be encountered in the hazardous environment of space, where materials are exposed to radiation, extreme temperatures, and microgravity.
In addition to the scientific understanding of materials and structures, exploration is shaped by the responses of crews to novel and severe environments. For instance, contested authority lines and crew frictions were the rule, not the exception, in early explorations, particularly when vessels sailed beyond the reach of their home governance. As humankind confronts unknown and extreme environments, it is only a matter of time before we encounter new disease pathogenesis. Thus, we can anticipate that new and unforeseen nutritional and radiation problems will pose major challenges for crew health, safety, and performance in space.
In the history of exploration, the importance of staging areas cannot be overestimated. Staging areas for navigation (e.g., the Canary Islands) were vital in acclimating sailors to voyages of increasing distances from “home.” Such staging areas were also vital as trading depots where stockpiles for protracted voyages could be stored. Discovery of new food types and food preparation techniques, as well as new sources of water, were key
to facilitating distant exploration. Similarly, experimentation with new navigational aids was facilitated in the relatively familiar environment of a staging station. With its large size and scientific focus, the ISS is likely to develop crucial experience as a type of proto-staging area.
It is extremely difficult to forecast the economic benefits of exploration. Indeed, the initial impetus for discovery of the New World was the quest for spice. While seeking spice, explorers discovered new continents. While looking for gold, they stumbled upon lands of unparalleled fertility. Way stations in space may offer similar uniquely valuable economic opportunities that are difficult to calculate in advance. The microgravity environment allows an entirely new way of crafting materials. A relatively safe environment close to Earth offers an opportunity (and revenues therefrom) for thousands of people to experience a microgravity environment. Furthermore, the selection criteria for space tourists will likely be less restrictive than those used for professional astronauts. As a result there will be opportunities for acquiring increasing amounts of medical insights in space.
Given that space voyages may eventually last for years and that an emergency return to Earth because of crew health or vessel material problems will be impractical, the safest way of venturing into space is to acquire experience with numerous missions of increasing complexity and duration. Such missions will reveal existing limitations as well as facilitate acquisition of new knowledge.
Throughout history, the exploration quest has demanded three things: that risks are balanced against the safety of the explorers, the tools are available to enable them to explore, and there are inspiring discoveries to be made. These remain key elements of a healthy space exploration program.
The obstacles faced by humanity in becoming a spacefaring species have been enormous. The United States has overcome many initial hurdles to deliver the lunar landings, the space shuttle, and, in partnership with other nations, the ISS. More than four decades after humans first traveled to the surface of the Moon, some 500 out of Earth’s nearly 7 billion people have traveled into space. Yet, of those, only two dozen have traveled further than low Earth orbit and none have traveled beyond the orbit of the Moon. Despite tremendous advances in technology, human exploration of space remains a tremendously difficult, risky, and expensive endeavor.
Looking to the future, significant improvements are needed in spacecraft, life support systems, and space technologies to enhance and enable the human and robotic missions that NASA will conduct under the U.S. space exploration policy. The missions beyond low Earth orbit to and back from planetary bodies and beyond will involve a combination of environmental risk factors such as reduced gravity levels and increased exposure to radiation. Human explorers will require advanced life support systems and will be subjected to extended-duration confinement in close quarters. For extended-duration missions conducted at large distances from Earth and for which resupply will not be an option, technologies that are self-sustaining and/or adaptive will be necessary. These missions present multidisciplinary scientific and engineering challenges and opportunities for enabling research that are both fundamental and applied in nature. Meeting these scientific challenges will require an understanding of biological and physical processes, as well as their interaction, in the presence of partial-gravity and microgravity environments.
In the context of extraordinary advances in the life and physical sciences and with the realization that national policy decisions will continue to shift near-term exploration goals, the committee focused on surveying broadly and intensively the scientific issues necessary to advance knowledge in the next decade. Such a task is never easy; it relies on interpolation and extrapolation from existing knowledge sources and educated assumptions about new developments. The committee grappled with all of these issues as well as the thorny problem of how to organize the scientific efforts themselves procedurally so that they would flourish in the next decade.
As described in the Preface, the current report is the outcome of a highly integrated effort by the committee and its panels, drawing on extensive input from the scientific community. Nevertheless, important differences exist between the various chapters developed by the individual panels. Potential metrics were shared and discussed
among the panels and the committee, and each panel selected, refined, and applied the specific metrics that were most appropriate for its own theme area. These metrics were later aggregated and synthesized into a common set of criteria against which all of the highest-priority recommendations were mapped. In organizing their chapter material, each panel worked from a common template, which they then revised to fit the demands of their subject material. Accordingly, each panel chapter (Chapters 4 through 10) contains a review of the current status of knowledge in the applicable disciplines and topics; an assessment of gaps that need to be addressed; recommendations to address these gaps; a selection of the recommendations that the authoring panel considers to be of the highest priority; and discussion of the time frame, facilities, and platforms needed to support the recommended research. Neither the order in which these chapters appear, nor their relative length, should be taken as an indication of the relative importance assigned to them. In general, topics with the greatest commonality were grouped together both in the report and within the chapters. Thus some chapters cover a much larger scientific “terrain” than others, some have a greater number of recent flight results to consider, and some with particularly technical topics require more detailed background discussion than others. Finally, each of these chapters was drafted by a different panel, and while all panels worked toward a similar format, their eventual approach to summarizing their material differed according to the unique characteristics and needs of the fields under review.
While the report recognizes the powerful advantages of the ISS in carrying out many types of critical research, the research was selected independently of the consideration of what platform should be used and whether that platform was available. Instead, platform needs were identified only after the research was selected.
The theme areas addressed by the seven panels were divided into five discipline areas and two integrative translational areas. In the latter, attention was given to the crosscutting science and technology issues for human survival in the space environment and to the translational research essential to the development of affordable space exploration systems. The concept of translational research has attracted considerable attention in recent years, in particular in the health sciences. Translational research seems important to almost everyone, and in the life sciences it has emerged as a priority of the National Institutes of Health. However, as pointed out by Woolf,2 translational research means different things to different people. Over time, the definition of translational research has been subject to much debate. In the area of medicine, the concept of a translational continuum has emerged as stretching from basic science discovery through early and late stages of application development and then onto dissemination and adoption of those applications in clinical health practice. In other research areas, the concept of translational research has emerged as research linking fundamental to applied science. Many perceive it as research carrying a promise of being transformative rather than incremental. While defining translational research uniformly across life and physical sciences is challenging, the committee has, for the purpose of this report, defined it as “the effective translation of knowledge, mechanisms, and techniques generated in one scientific domain, such as basic or fundamental science, into new scientific tools or applications that advance research in another scientific domain, such as clinical or applied science.”
As noted previously, final panel recommendations resulted from a joint process in which the advisory panels interacted with each other and with the survey committee. The resulting set of highest-priority research recommendations form the basis of the research portfolio laid out in Chapter 13. In addition, as per the committee’s statement of task, budget considerations did not play a role in the selection of research, the setting of priorities, or the creation of an integrated portfolio. However, the committee was cognizant of the role that both budget and policy direction will play in implementing the recommended portfolio and has therefore provided guidance and examples in Chapter 13 for how NASA might approach a policy-related ordering of an integrated research portfolio.
In the process of discovery and analysis, certain themes arose repeatedly in discussions with the community and within the panels and committee. These themes related to the obstacles that would need to be overcome to enable the development of a successful research program. The results of those discussions and analysis, which are presented in Chapter 12, are considered by the committee and its panels to be at least equal in importance to the selection of research.
To provide context for the discussions in the report, the committee has also summarized, to the best of its ability, the available information on the research facilities that are, or are likely to become, available to the scientific community supporting NASA’s life and physical sciences research. This information, along with a very general overview of NASA’s program evolution in this area, is provided in the report’s opening chapters.
1. National Research Council. 2009. America’s Future in Space: Aligning the Civil Space Program with National Needs. The National Academies Press, Washington, D.C.
2. Woolf, S.H. 2008. The meaning of translational research and why it matters. Journal of the American Medical Association 299:211-213.