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Annual Report 1991: Summaries of Reports Space Studies Board Annual Reportâ1991 3 Summaries of Reports 3.1 Assessment of Programs in Solar and Space Physicsâ1991 A Report of the Committee on Solar and Space Physics INTRODUCTION The Committee on Solar and Space Physics (CSSP) and the Committee on Solar Terrestrial Research (CSTR) are both responsible for providing scientific advice to U.S. government agencies in the overlapping fields of solar physics, space physics, and solar-terrestrial relationships. The CSSP is a subcommittee of and reports to the Space Studies Board (SSB); the CSTR has a similar REPORT MENU relationship to the Board on Atmospheric Sciences and Climate (BASC). CSSP NOTICE and CSTR now function as a single, federated committee reporting to both the FROM THE CHAIR SSB and BASC. This assessment report has been written in response to a CHAPTER 1 request by the SSB for an assessment of the way in which prior CHAPTER 2 recommendations of the National Research Council (NRC) are being CHAPTER 3 CHAPTER 4 implemented by the appropriate federal agencies (See Appendix A). The CHAPTER 5 federated committee has expanded the scope of the study beyond that requested APPENDIX by the SSB to include an assessment of responses to NRC reports in solar- terrestrial research that are beyond the space-oriented scope of the SSB. This report was reviewed and approved by the SSB. STATUS OF DISCIPLINE The scientific purview of the CSSP and CSTR covers the disciplines of solar physics, heliospheric physics, cosmic ray physics, magnetospheric physics, middle- and upper-atmosphere physics, solar-terrestrial coupling, and comparative planetary studies. The assessment has two major sections: discipline-specific issues and common issues. file:///C|/SSB_old_web/an91ch3.htm (1 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports Discipline-Specific Issues Solar Physics Good progress has been made in studies of solar irradiance variations, high-energy emissions, and solar magnetism, resulting in part from the Solar Maximum Mission (SMM) and the development of ground-based Stokes polarimeters. Fundamental studies of helioseismology and solar neutrinos are slowly progressing. The principal problem areas are the lack of prospects for space observations of the highest-energy solar phenomena during both the current and the next solar maximum, multiyear gaps in solar irradiance measurements, lack of a funded plan for U.S. participation in the Large Earth- Based Solar Telescope (LEST), and most critically, the extraordinarily long delay in achieving a new start for the Orbiting Solar Laboratory (OSL). Because of the breadth and importance of its scientific goals, OSL remains the top-priority candidate for a new mission start. Heliospheric Physics Extremely valuable data on the properties of the outer heliosphere continue to be received from the Pioneer and Voyager spacecraft. With the successful launch of Ulysses, the first in situ measurements of the three- dimensional structure of the heliosphere will be obtained in 1993-1995. Both Ulysses and Wind (to be launched in 1993) are expected to allow great advances in our knowledge of the abundance and charge state of solar wind ions. Problem areas are the lack of advanced development of technology required for future missions and the decline in support for ground-based radio observations of the solar corona and solar wind. Cosmic Ray Physics Data returned by the Voyager and Pioneer spacecraft, launched in the 1970s, gave valuable new insights into the modulation of galactic cosmic rays, the nature of anomalous cosmic rays, and the variable abundances of solar energetic particles. Although several other missions and experiments responsive to NRC recommendations were started, many of them were subsequently canceled or postponed indefinitely; others have been stretched out over more than a decade. The augmentation of the Explorer Program has led to the selection of two new cosmic ray missions-the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) and the Advanced Composition Explorer (ACE). file:///C|/SSB_old_web/an91ch3.htm (2 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports Magnetospheric Physics During the 1980s, a number of advances occurred that increased our understanding of magnetospheric physics, including definitive observations that the ionosphere is a major source of magnetospheric particles, initial measurements of the composition and charge state of the ring current, the discovery of plasmoids traveling at high velocity away from the Earth, and the development of new models of the Earth's magnetopause, bow shock, and foreshock regions. The key magnetospheric project, the International Solar- Terrestrial Physics (ISTP) program, has been subject to delays and descoping actions. Deletion of the Equator spacecraft eliminated crucial measurements of the equatorial magnetosphere. NASA is currently trying to develop other ways to obtain those key measurements. The several ISTP elements may, however, be spread out in time to the extent that there will be little of the simultaneity of measurements so vital to accomplishing the ISTP objectives. Although the mission of the recently launched Combined Release and Radiation Effects Satellite (CRRES) is to perform some active magnetospheric experiments, much of the active experiment program has been lost as a major element of magnetospheric research because of budget cuts and delays. Middle- and Upper-Atmosphere Physics There has been much progress in implementing NRC recommendations in this discipline; the Middle Atmosphere Program (MAP), the Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) program, and a series of satellite observations gave a major boost to studies of chemical, dynamical, radiation, and coupling processes. Recent studies of the polar ozone depletion are especially noteworthy, but the combination of long delays, such as in Upper Atmosphere Research Satellite (UARS); the lack of a vigorous research program on the effects of solar activity on the middle atmosphere; and some gaps in addressing the global electric circuit problem, has reduced expected progress in some important areas. Solar-Terrestrial Coupling Progress in solar-terrestrial coupling has been closely related to results in the areas of magnetospheric and atmospheric physics. Those results, mostly tied to programs defined in the 1970s and conducted in the 1980s, have improved our understanding of the solar wind-magnetosphere-ionosphere interactions and resulting dynamics. The programmatic delays from planning to implementation have meant that most of the solar-terrestrial recommendations made through the 1980s will not be acted on until the 1990s. Illustrative of programs that are expected to provide major advances in this area are the ISTP, CEDAR, and Geospace Environmental Modeling (GEM) programs. Comparative Planetary Studies file:///C|/SSB_old_web/an91ch3.htm (3 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports Observations of planetary magnetospheres and atmospheres continue to be an important element of solar system exploration. The Voyager flybys of Uranus and Neptune added two new planets to the list of objects available for comparative studies of planetary magnetospheres and magnetosphere- ionosphere-atmosphere interactions. But again, major delays (e.g., in the Galileo and CRAF/Cassini missions) and the absence of a U.S. mission to comet Halley have significantly slowed the implementation of recommendations in this area. Common Issues Program Management The recommended establishment of a separate Space Physics Division within NASA's Office of Space Science and Applications (OSSA) has been successfully implemented. The recommended reorganization of the solar physics program within NSF is still under consideration. The recommended interagency coordination council for solar-terrestrial research was formed, but has not been active since 1987. International coordination has been excellent. Data Archiving and Access The recommended solar-terrestrial Central Data Catalog and Data Access Network have not been implemented. Although there have been some initial developments in this area, progress has been painfully slow. A great deal needs to be done before the NRC recommendations are met. Explorer Program The recommendations of an augmentation of the Explorer program and the institution of a two-stage selection process have both been implemented, as has the recommendation for a return to a concept of small, simple missions. The recommended level of an average of one Explorer per year for solar and space physics has not been reached, however, because cost overruns in the current Explorer program continue to cause delays. Coordinated Programs and Synoptic Observations Several initiatives have responded to recommendations for coordinated programs. Examples include ISTP and CEDAR. To date, there is no national program or policy supporting recommendations for synoptic observations of the fundamental parameters of the solar-terrestrial system. One exception was NASA's successful effort to increase the data return from the IMP-8 spacecraft. file:///C|/SSB_old_web/an91ch3.htm (4 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports Research and Analysis Even though support and augmentation of the research base have been recommended by virtually every report, the base appears to have eroded. In addition to this major concern, agency responses to other specific recommendations in this area include the following: 1. Theory and modeling. NASA's Space Physics Theory Program (previously called the Solar-Terrestrial Theory Program) has been very successful, but there is concern about the steady erosion of average grant sizes in real-year dollars. 2. Supercomputing. Recommendations for access to supercomputers for solar-terrestrial research have largely been met. The limiting factor for many scientists is now the lack of the small, inexpensive workstations required to communicate with the supercomputers and to analyze and display their output. 3. Suborbital and Spartan programs. After some floundering during the mid-1980s, NASA's balloon program is currently fairly healthy, with the major problem being limited funding for instrument development. The rocket program has declined because funding has not kept up with inflation, active experiments were removed from the program, and funds were diverted to development of the Spartan program (a diversion with which the NRC concurred). The Spartan program effectively ended with the Challenger accident and, in retrospect, the resources expended for the Spartan program adversely affected the rocket-type science program it was meant to help. Education To date, only a few programs have set aside specific funds to support educational components of their activities. The CEDAR program has shown notable success in this area. CONCLUSIONS In summary, there has been considerable scientific progress during the past decade, with the bulk of the advances stemming from programs started in the 1970s, prior to the NRC recommendations considered in this report. Progress on the NRC recommendations of the 1980s has been generally slow, however, and in some cases nonexistent. Cancellations, long delays, and major programmatic restructuring have been routine. The perception is that initial responses have been positive but that actions in the implementation phases have not been carried through to achieve the goals embodied in the recommendations. file:///C|/SSB_old_web/an91ch3.htm (5 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports Because of these cancellations, delays, and stretch outs, the scientific goals and most of the specific recommendations for each of the subdisciplines remain valid. There is presently no need for a new set of scientific goals and priorities. The most recent NRC report that set out an implementation plan for solar and space physics was written in 1985. Although parts of that report are now obsolete, the CSSP/CSTR plans to review NASA's Strategic Plan currently under development rather than to develop an implementation strategy of its own at the present time. The federated committee also plans to further examine issues in the agencies' research and analysis programs. 3.2 Assessment of Programs in Space Biology and Medicineâ1991 A Report of the Committee on Space Biology and Medicine INTRODUCTION This report was undertaken at the request of the Space Studies Board to provide an up-to-date assessment of the status of the implementation in the civil space program of the various research strategies and recommendations published in previous reports. This report limits its comments to information contained in the three most recent reports (SSB 1979, 1987, and 1988). The most comprehensive strategy was the report published in 1987, A Strategy for Space Biology and Medical Science for the 1980s and 1990s (SSB, 1987), edited by Jay Goldberg, University of Chicago. The Goldberg Strategy (as the 1987 strategy report is referred to in this report) forms the primary basis for the current evaluation, although reference is also made to several previous reports concerning life sciences by the Committee on Space Biology and Medicine (CSBM) and the Life Sciences Task Group of the Space Science Board that was part of the 1988 Space Science in the Twenty-First Century report. Space biology and medicine includes-in addition to biological and medical subdisciplines-human behavior, radiation, and closed ecological life support systems. The Goldberg Strategy defined four major goals: 1. To describe and understand human adaptation to the space environment and readaptation upon return to earth. 2. To use the knowledge so obtained to devise procedures that will improve the health, safety, comfort, and performance of the astronauts. 3. To understand the role that gravity plays in the biological processes of file:///C|/SSB_old_web/an91ch3.htm (6 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports both plants and animals. 4. To determine if any biological phenomenon that arises in an individual organism or small group of organisms is better studied in space than on earth. The first two goals have taken on new emphasis since the announcement of the Space Exploration Initiative (SEI), enunciated by the President in July 1989, for a sequential progression of human activities in space, and extending potential human missions to years in duration. In discussing the major imperatives for research in space biology and medicine, this assessment of the implementation of the research strategies has categorized research topics relative to the urgency that would be dictated by proceeding with a space exploration initiative. The conduct of research in space biology and medicine is influenced by the way the civil space agency, National Aeronautics and Space Administration (NASA), is structured and managed. Consequently, previous reports by CSBM have contained numerous recommendations concerning science program and policy issues. Because of the importance of these issues in approaching the various research goals, progress in implementation of these goals is discussed at the outset. This is followed by topics that have the greatest potential of affecting human performance and/or survivability during sustained space exploration. These topics include research areas concerning human physiology in microgravity, human behavior during long-term missions, and the radiation environments of space. Finally, the report contains sections on developmental and cell biology, human reproduction, plant biology, and issues associated with the development of a closed ecological life support system. The latter topics reflect areas that, while not deemed crucial to survival in space for durations of a few years, could become critical to longer-term human habitation. In addition, these topics represent major research areas in which space could be especially valuable in the study of basic biological phenomena. SCIENCE PROGRAM AND POLICY ISSUES Published strategy reports (e.g., SSB 1979, 1987, 1988) contain recommendations concerning how NASA manages its life sciences research and the design and utilization of laboratory space on a space station. In the area of management, recommendations were as follows: 1. Standing panels of 5 to 10 scientists should be created to review, update, and refine research strategies in each subdiscipline of space biology and medicine. 2. Announcements of Opportunity (AOs) and NASA Research Announcements (NRAs) concerned with Shuttle flights and the space station should be targeted to a particular subdiscipline and should state explicitly the file:///C|/SSB_old_web/an91ch3.htm (7 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports major research questions that the mission is intended to address. 3. NASA should actively solicit the participation of other relevant federal agencies such as NIH and NSF in the design and conduct of research related to the major questions that need to be answered. Recommendations related to a space station were as follows: 1. A space station should contain a dedicated life sciences laboratory, and research time should be allocated in 3- to 6-month increments for individual subdisciplines. 2. A variable force centrifuge of the largest possible dimensions should be incorporated into a space station. 3. Dedicated microprocessors should be used for process control, data storage, or both, and rapid communication in real time with ground-based research teams should be a goal. In the area of management, NASA either has implemented or is in the process of implementing all of the recommendations made. The internal life sciences advisory structure has been reorganized as recommended. The NRAs that are now being released are more highly focused, and NASA is now actively cooperating with other federal agencies such as National Institutes of Health (NIH), National Science Foundation (NSF), and the U.S. Department of Agriculture (USDA), as well as numerous foreign partners. None of the recommendations concerning design and utilization of the space station have been implemented in current plans for the facility; however, planning for inclusion of a centrifuge is under way. RESEARCH IN SPACE BIOLOGY AND MEDICINE Human Physiology There has been a general perception that since a small number of Soviet cosmonauts have survived in the microgravity of space in low earth orbit for as long as a year, there are no major physiological problems likely to preclude longer-term human exploration beyond low earth orbit. The committee has had, over the years, access to anecdotal data from the Soviet space program. This anecdotal information is, while interesting, not sufficiently reliable for drawing conclusions or in planning the U.S. program for a number of reasons. There are differences in experimental protocols and controls in laboratory equipment, and the Soviets do not publish their results in refereed scientific journals. However, increased recent cooperative activities between the Soviets and the United file:///C|/SSB_old_web/an91ch3.htm (8 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports States suggest promise for the future in standardized experimental procedures and data exchange. The current evaluation of progress in space biology and medical research illustrates that all of the major physiological problems characteristic of prolonged human exposure to the microgravity environment of space remain unsolved. First, and of greatest concern, is bone, muscle, and mineral metabolism; second, cardiovascular and homeostatic functions; and third, sensorimotor integration. Bone, Muscle, and Mineral Metabolism Eight major goals were defined for the study of bone and mineral metabolism: (1) determine the temporal sequence of bone remodeling in response to microgravity; (2) establish the reversibility of this process on return to a 1-g environment; (3) establish the relationship between muscle activity and bone function; (4) devise countermeasures to prevent bone loss; (5) establish the cellular mechanisms responsible for bone loss; (6) evaluate the interdependence of calcium homeostasis and bone remodeling; (7) determine the etiology of pathologic calcification; and (8) establish the biomechanics of the skeleton under microgravity conditions. Understanding the etiology of bone loss (osteopenia) is the focus of an enormous research program within the NIH as well as an area of research that has received major attention by NASA scientists-especially over the past 5 years. NASA scientists and others supported by NASA have developed an animal model to study bone loss. In addition, human studies correlating inactivity (bed rest) to factors such as diminished bone mass and increased urinary calcium have also proven to be useful models for potential changes during extended spaceflight. However, of the eight major goals listed above, only the first has been addressed in these studies, and the information that has been obtained using the animal model chosen (rat) is of limited value because of the dissimilarities between bone physiology in rats and normal human physiology. Considerable research remains to be conducted. Increased interaction with the major research effort at NIH would be of enormous value for solving the overall problems of bone and muscle atrophy that have been observed in microgravity. Cardiovascular and Other Homeostatic Systems The cardiovascular and neuroendocrine elements of the circulatory system focus respectively on basic cardiovascular function and the influences of regulatory systems on these functions. Additional areas under this topic include immunology, hematopoiesis, and wound healing. Circulatory AdjustmentsâThe major goals have been to (1) understand acute (0 to 2 weeks), medium-term (2 weeks to 3 months), and long-term (greater than 3 months) changes in the cardiovascular system in microgravity; (2) examine the file:///C|/SSB_old_web/an91ch3.htm (9 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports validity of ground-based models of microgravity-induced changes; and (3) define measures (countermeasures) that will alleviate changes in microgravity and hasten human adaptation upon return to a 1-g environment. A better understanding of cardiovascular and pulmonary physiology in microgravity has been a major goal of previous, current, and planned investigations. Measurements on humans before, during, and after several Shuttle flights have provided echocardiographic data on cardiac dimensions and function. Some countermeasures such as oral saline loading have been tested to prevent post-flight orthostatic hypotension. A major drawback has been the limited number of subjects available for study. There is a need to develop animal models for both ground-based and flight experiments. Hormones that affect the cardiovascular system also remain to be tested in the context of cardiovascular changes that occur in space. Some hormone measurements were conducted on Skylab flights, and additional studies are planned on upcoming Shuttle flights. However, many of these experiments fail to take into account fairly recent observations concerning the rhythmic nature of changes as a function of circadian variations. ImmunologyâImmune cells in mammalian bone marrow and lymphoid organs initiate and regulate lymphocyte and antibody responses as well as control the production and function of cells in the blood and connective tissues. The major goal in this area is to determine if cells of the immune system can proliferate in space and maintain a normal immune system. The occurrence of serious infections in space has been very uncommon, and most studies of immunity in space have been directed to the detection of abnormalities in human and animal lymphocyte numbers and morphology in space. Spaceflight is known to result in significant reductions of both plasma volume and red blood cell mass within days. Recent studies have shown that lymphocytes do not respond to stimuli that normally cause division, suggesting an impaired ability to proliferate in space. This could have profound implications for the immune and hematopoietic system. An expanded effort to investigate possible immune deficiencies coupled with the development of cell models to test immune and bone cell function in microgravity requires a higher priority. Sensorimotor Integration As indicated in the Goldberg report, the neuronal mechanisms underlying a sense of spatial orientation are complex, as yet poorly understood, and are directly relevant to assuring the effective functioning of humans involved in space missions. The 1987 strategy report recommended a vigorous program of ground- based and flight research aimed at understanding these mechanisms as they operate on earth, in space, and on return from microgravity to high-gravity environments. These studies become all the more significant if one considers the use of artificial gravity (rotating spacecraft) as an attempt to ameliorate the effects of microgravity on human physiology. Specific goals are to (1) study in microgravity how the vestibuloocular reflex (VOR) converts head motion into file:///C|/SSB_old_web/an91ch3.htm (10 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports compensatory eye movement, (2) investigate the neural processing mechanisms in the vestibular system in both normal gravity and microgravity, (3) focus on adaptive mechanisms that alter vestibular processing in response to altered feedback from the environment, and (4) investigate more fully the etiology of motion sickness in microgravity. Overall, NASA has made a concerted effort to undertake appropriate, quality research in the sensorimotor area. These efforts include many studies supported through external investigators and the establishment of an excellent Vestibular Research Facility (VRF) at Ames Research Center. In spite of limited flight opportunities, considerable progress has also been made studying sensorimotor performance in microgravity. Several planned experiments are promising. However, in spite of this generally positive view, no single countermeasure has yet been developed that corrects the problem of space motion sickness. Perhaps the syndrome, with individual variations, is actually several distinguishable syndromes. This possibility, if documented, might dictate new research approaches. Behavior, Performance, and Human Factors The major goals for space research as it relates to human behavior are to develop (1) spacecraft environments, (2) interfaces with equipment, (3) work- leisure schedules, and (4) the social organization that will optimize the efficiency, safety, and satisfaction of crews during long-term spaceflight. With the exception of group and organizational factors, there is research in progress along the lines recommended in published research strategies. Much of the progress that has occurred derives from well-funded research programs in aviation sponsored by the Federal Aviation Administration (FAA) and to a lesser extent from NASA's aviation research program. However, this type of research, while useful, cannot provide all of the information needed to support a long-term human presence in space. As opportunities for experimentation that will exist during long-duration spaceflight will always be extremely limited, there must be a well-developed ground-based program of research employing a variety of research settings. At this point in time, NASA has no plans to develop long-term confinement studies using ground-based research settings. Developmental and Cell Biology The major goal for developmental biology as outlined in all three research strategies is to determine whether any organism can develop from fertilization through the formation of viable gametes in the next generation, i.e., from egg to egg, in the microgravity environment of space. In the event that normal development does not occur, the priority is to determine which period of file:///C|/SSB_old_web/an91ch3.htm (11 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports development is most sensitive to microgravity. Potentially, research on specific developmental phases (e.g., fertilization to initial organ formation) would suggest detailed studies on the function and differentiation of individual cells or groups of cells. In approaching these goals, we have recommended studies on several representative organisms including both invertebrate and vertebrate animals. While the latter would include mammals such as mice, it also encompasses the question, can humans reproduce in space? The importance of these questions relates to the ability to establish permanent human colonies in space as well as to the possibility that the space environment could be a particularly advantageous environment to study basic developmental research. A number of diverse organisms have been subjected to microgravity for varying periods of time. The results of these studies have been inconsistent. Both normal and abnormal development have been observed, dependent on the organism and the stage of development at which the material was subjected to microgravity. To our knowledge, no animal species has ever been carried through one complete life cycle in the microgravity of space. Plant Biology Any strategy that visualizes a long-term sustained human presence in space absolutely requires the ability to continuously grow and reproduce various plant species over multiple generations. A related goal, which has implications for agriculture generally, is to understand the mechanism(s) involved in gravity sensing by plants. This requires an emphasis on ground-based research as well as research in space. For the most part, observations on plants exposed to microgravity have been anecdotal. It has been demonstrated repeatedly that plants do grow in microgravity. However, whether plants can grow normally remains to be determined. Significantly, results of studies on the German D-1 mission, which incorporated onboard 1-g centrifuge controls, indicate that single plant cells behave normally or even exhibit accelerated development. In contrast, the roots of seedlings germinated in microgravity grew straight out from the seed, and the same roots contained starch grains (statolyths) which were more or less randomly distributed in their cells. Control roots centrifuged at 1 g on the flight, were normally gravitropic. Cytological studies of roots flown under a variety of conditions in space have consistently revealed reduced cell divisions as well as a variety of chromosomal abnormalities. At the same time, some Soviet experiments using the plant arabidopsis indicate that at least this plant develops normally through the flowering stage. However, in the Soviet experiments, fruit set was decreased and seeds brought back to earth germinated less efficiently than ground-based controls. Long-term flight experiments are required to determine if a variety of plant species can grow normally in microgravity and, in particular, if they can produce viable seeds. file:///C|/SSB_old_web/an91ch3.htm (12 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports Closed Ecological Life Support Systems The closed ecological life support system (CELSS) program at NASA is attempting to create an integrated self-sustaining system capable of providing food, potable water, and a breathable atmosphere for space crews during missions of long-term duration. An effective CELSS must have subsystems both for plant and animal growth, food processing, and waste management. These have been described to some extent on previous pages. A CELSS must be much more than a "greenhouse in space." It must be a multispecific ecosystem operating in a small closed environment. Thus, although the concept is easily articulated, numerous areas of ignorance remain. Based on consideration of primarily agricultural plant species, a small number have been selected for further investigation. These include wheat, potato, soybean, and tomato. Growth chamber studies have been initiated, both at NASA and in university laboratories, with the aim of defining the conditions required for optimum rates of dry matter production. Although most research has been done with open systems, experiments with closed systems have recently been initiated. No attention has been paid to the use of techniques of plant breeding or genetic engineering to "design" ideal plants for a CELSS system. No experiments have yet been performed in microgravity to determine if current systems can function in space. In short, a considerable increase in research efforts, and in support for those efforts, is required in order to reach the desired goals. Radiation Biology While the radiation environment within the magnetosphere is fairly well known, as are the biological effects of low energy transfer (LET) radiations from protons and electrons, considerably better quantitative data on LET dose rates beyond the magnetosphere are still required. In particular, better predictability of the occurrence and magnitude of energetic particles from solar flares is required; radiation from solar flares can be life-threatening in relatively short time periods. Major goals of radiation research are to quantify high-energy (HZE) particles in space and to understand the biological effects of HZE particles. The likely long- term biological effects of exposure to HZE particles is an increased incidence of cancer and brain damage. NASA has maintained a limited but ongoing research program both in radiation dosimetry and radiobiology including ground-based programs on the effect of fragmentation of HZE particles and on the secondary particles. In the field of radiobiology, NASA has supported studies dealing with the biological effects of HZE particles. Limited flight data suggest a synergism between HZE file:///C|/SSB_old_web/an91ch3.htm (13 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports particle hits and microgravity. This research requires increased attention. In particular, ground-based studies on biological effects of HZE particles are currently performed in the United States at the Billion Electron Volts Linear Accelerator (BEVALAC) at Lawrence Berkeley Laboratory. This research may be drastically curtailed if the facility is unavailable after 1993 as is currently planned. Use of similar facilities in other countries, while feasible, is not necessarily practical because of the necessity for transporting large numbers of animals and associated experimental controls, and regular transport and accommodation of U.S. research teams. CONCLUSIONS Over the past 30 or more years, the Space Studies Board and its various committees have published hundreds of recommendations concerning life sciences research. Several particularly noteworthy themes appear consistently: (1) balance-the need for a well-balanced research program in terms of ground versus flight, basic versus clinical, and internal versus extramural; (2) excellence- because of the extremely limited number of flight opportunities (as well as their associated relative costs), the need for absolute excellence in the research that is conducted, in terms of topic, protocol, and investigator, and (3) facilities-the single most important facility for life sciences research in space, an on-board, variable force centrifuge. In this first assessment report, the Committee on Space Biology and Medicine emphasizes that these long-standing themes remain as essential today as when first articulated. On the brink of the twenty-first century, the nation is contemplating the goal of human space exploration; consequently, the themes bear repeating. Each is a critical component of what will be necessary to successfully achieve such a goal. 3.3 Assessment of Solar System Exploration Programsâ1991 A Report of the Committee on Planetary and Lunar Exploration SUMMARY The advisory base for the Committee on Planetary and Lunar Exploration (COMPLEX) is made up of a series of documents published over the last 15 years. These documents provide a rationale for planetary exploration, a strategy for carrying out scientific study of the solar system, and a series of recommendations to NASA for implementation of this strategy. This report file:///C|/SSB_old_web/an91ch3.htm (14 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports reviews the recommendations of the committee and the status of the field of planetary exploration relative to those recommendations. NASA's planetary exploration program has made great strides in the last few years. Much of the strategy for exploration of the planets proposed by COMPLEX has been implemented. Other areas await the arrival of planned or approved space missions at their targets. The rate at which the proposed scientific objectives would be achieved was in some cases overestimated by COMPLEX; these objectives still await fulfillment. Significant scientific objectives have been achieved in exploration of the outer planets and comets. U.S.-European cooperation is proceeding well. Further exploration of Venus is under way and of Mars is imminent. In contrast, little progress has been made in more intensive study of the Moon and Mercury and in preliminary reconnaissance of asteroids and Pluto. Exploration on the surface of Venus, in the inner Jupiter magnetosphere, and in the deep atmospheres of the outer planets requires significant technical developments that should be undertaken. These developments include high-temperature and high-pressure instruments, radiation-hardened spacecraft, and development of low-thrust propulsion. The recommendations in the areas of detection and study of other solar systems and in exobiology research are so recent that it is premature to evaluate the status of current activities. Areas of concern to the planetary science community include the absence of a plan to carry out the extended mission for Magellan, the lack of reserves in approved flight missions, and the inappropriate use of research and analysis funds as a reserve for mission overruns. The committee views positively the proposed planetary Discovery mission line and NASA's efforts to encourage interdisciplinary research. 3.4 Assessment of Satellite Earth Observation Programsâ1991 A Report of the Committee on Earth Studies SUMMARY During the past decade, the Space Studies Board, its Committee on Earth Studies (CES), and other bodies of the National Research Council have provided the federal government with a substantial body of advice on the study of the Earth from space. Together, these documents have contained an overall strategy for science and applications using Earth observation spacecraft and have established a set of specific recommendations for implementation of the strategic advice. This report assesses the status of the nation's civil Earth observation file:///C|/SSB_old_web/an91ch3.htm (15 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports programs in relation to this existing body of advice and provides additional advice on how to address the unfulfilled objectives and recommendations in the current scientific and programmatic context. Specifically, the report reviews the content of the satellite Earth observation programs of the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and the Landsat system operated by the Earth Observation Satellite (EOSAT) Company as of the spring of 1991. The NASA programs are within the agency's Mission to Planet Earth initiative, which includes the Earth Observing System (EOS) and its related data and information system, the Earth Probe small- and moderate-size mission line, and a number of "precursor" missions such as the Upper Atmosphere Research Satellite (UARS) and the Ocean Topography Experiment (TOPEX/Poseidon). The NOAA programs include the two meteorological satellite series, the Polar-Orbiting Operational Environmental Satellites (POES) and the Geostationary Operational Environmental Satellites (GOES). Also considered in this assessment are some of the Defense Department's operational and experimental spacecraft, including the Defense Meteorological Satellite Program (DMSP), the Global Positioning System (GPS), and the completed Geosat mission. Finally, because the U.S. programs should be viewed in the broader international context, the experimental, operational, and commercial satellite programs of other countries are also discussed briefly. The committee has found that substantial progress has been made in recent years in the earth science programs of NASA, although many of the science objectives previously established by this and other science advisory committees have not yet been fully achieved. More importantly, a majority of past CES recommendations are expected to be addressed by the funded and planned missions and related research programs that have been proposed for this decade through the nationally and internationally coordinated U.S. Global Change Research Program (USGCRP) and Mission to Planet Earth. The committee concludes that with the implementation of Mission to Planet Earth, together with the planned modernization of the NOAA environmental satellite programs and the continuation of vigorous research and development of remote sensing and related technologies, the United States will ensure its leadership in Earth observations from space. The committee has found NASA's plans for Mission to Planet Earth to be responsive to the scientific objectives and recommendations established in past NRC reports, with the exception of several shortcomings noted below and some additional ones expressed in the body of the report. Development of the EOS-A spacecraft and instrument complement, as well as the missions currently planned under the Earth Probe line, should proceed without delay in order to achieve the recommended science objectives. The committee also supports the instrument complement under consideration for EOS-B, but recommends that NASA carefully consider the optimum platform and orbit configuration in light of all scientific requirements. For spaceborne studies of the atmosphere and climate, the most file:///C|/SSB_old_web/an91ch3.htm (16 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports significant scientific objectives will be supported by the data collected by NASA and NOAA spacecraft. Substantial progress also has been made by NASA and NOAA programs in fulfilling the space-related scientific objectives for physical oceanography, cryospheric studies, studies of tectonic deformation and variations in the Earth's rotation, and certain aspects of global biology, ecology, and biogeochemical cycles. Particularly noteworthy are NASA's support of general research and analysis (R&A) programs in the earth sciences during the past decade in the absence of many flight programs, and the high-priority attention now given by that agency to data management. Areas of scientific research where considerably less progress has been made with Earth observation spacecraft include hydrology, land-surface geology and vegetation, and the Earth's gravitational and magnetic fields. Research in the first two of these areas has been hampered largely by the high cost of obtaining data from commercially operated remote sensing systems such as Landsat. In the future, they would be further impeded by NASA's delays in flying advanced land-surface sensors such as the Synthetic Aperture Radar (SAR) and the High- Resolution Imaging Spectrometer (HIRIS) under the EOS program. The continued development and earliest possible deployment of the HIRIS and SAR instruments would significantly improve our ability to perform process studies and research in those areas. Exclusive reliance on sun-synchronous polar-orbiting satellites in the EOS program would also be inadequate for monitoring a number of important processes-such as the Earth's radiative balance, the formation of clouds, and biological productivity-that vary extensively throughout the diurnal cycle. Insufficient progress in the study of the Earth's gravitational and magnetic fields has been due to the lack of specific flight opportunities, despite long- standing recommendations by the scientific community to address them. Maintaining an accurate reference system based on space geodesy techniques would be useful for monitoring long-term global change indicators such as mean sea-level change. In meeting the goals of the Mission to Planet Earth and the USGCRP, the agencies still need to complete development of a comprehensive observational strategy that preserves long-term continuity of the highest-priority measurements and makes the best use of existing resources. In light of limited federal budgetary resources, the committee considers it important for NASA, NOAA, and their space agency partners to: Maximize observational coverage by (1) eliminating gaps in coverage of the electromagnetic spectrum through better coordination of their respective programs and (2) reducing redundancies, with the exception of those redundancies that either help maintain continuity of key measurements or that provide multiple observations of variables with significant diurnal variations. Mount a special effort to ensure the absolute calibration and intercalibration of all Earth observation instruments to the highest achievable accuracy. file:///C|/SSB_old_web/an91ch3.htm (17 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports Formulate a backup plan to be implemented in case of an instrument failure, to help ensure continuity in long-term observations such as those planned for EOS. This strategy may consist of the generation of alternative geophysical parameters, albeit less effective ones, either from complementary EOS instruments or from sensors flying on other NASA, U.S., or foreign spacecraft. Develop a plan for the surface and in situ data-gathering technologies and programs that are needed to complement Earth observations from space. The NASA aircraft and suborbital programs should be an integral part of this plan. Continue to transfer historical data sets onto secure media and improve the maintenance of long-term data archives. Both the development and implementation of this comprehensive observational strategy should be done in consultation with the scientific community. The implementation of the EOS Data and Information System (EOSDIS) and related NOAA data management initiatives is crucial to the success of future earth science and environmental research. It is important for NASA to continue to develop existing "pathfinder" data sets in cooperation with NOAA, and to include the data sets that will be collected by the European Earth Remote-Sensing Satellite, UARS, and TOPEX/Poseidon for prototype studies in developing the EOSDIS. The organizational emphasis on data systems and modeling in the recent reorganization of NASA's Earth Science and Applications Division is appropriate. The loss of identity of the traditional earth science disciplines, however, raises concerns that a balanced treatment among the disciplines may be difficult to maintain. The responsibilities of the new organizational units ought to be sufficiently broad to accommodate the requisite elements of the previous discipline structure. The status of operational and commercial applications is in a less healthy state. Although NOAA's POES program is on track and progressing in the development of next-generation spacecraft and sensors, the agency's GOES series has encountered serious difficulties. The two-satellite GOES system is currently operating with only one spacecraft, and the development of the new GOES series, which is being carried out in conjunction with NASA, is severely over budget and behind schedule. A number of instruments developed by NASA in the past, such as the Earth Radiation Budget Experiment scanner, the Coastal Zone Color Scanner, and the Total Ozone Mapping Spectrometer, have not been adopted by NOAA for operational implementation despite the demonstrated maturity of the technology and the well-recognized need for such continuous measurements. Although NASA and NOAA have reached a tentative agreement on the file:///C|/SSB_old_web/an91ch3.htm (18 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports designation of several EOS instruments as "pre-operational," the framework of the eventual transfer has not been worked out and the agencies have not yet agreed on the future status of the important Moderate-Resolution Imaging Spectrometer (MODIS) instrument. Past difficulties in transferring well-tested experimental instruments to operational status underscore the imperative for the federal government to arrive at a firm and comprehensive agreement on NASA's and NOAA's responsibilities, and on funding for the eventual transfer of key EOS instruments to a long-term monitoring program. The transfer of the Landsat system from NOAA to the private sector in 1985 was premature and poorly executed. Significant doubts about the future of this important remote sensing asset remain, and existing policies appear to be ineffective in assuring the future continuity of Landsat observations. The integration of the Landsat data into the research framework of the Mission to Planet Earth and USGCRP is especially important. Support of research and development of the applications of remote sensing data has been reduced substantially at NASA during the past decade. Although NOAA and the commercial sector have primary responsibility for operational remote sensing, NASA has a mandate for supporting research in, and development of, broader remote sensing applications. It is important for the agency to incorporate potential applications of EOS into its planning for the program, while preserving the primacy of the EOS program's scientific goals and objectives. These activities would best be coordinated with industry and with the commercial and government applications communities. The text that follows expands on the issues and recommendations highlighted in this summary, and contains a number of additional suggestions for improving our nation's satellite Earth observation programs. file:///C|/SSB_old_web/an91ch3.htm (19 of 20) [6/18/2004 10:26:44 AM]
Annual Report 1991: Summaries of Reports Last update 2/23/00 at 12:39 pm Site managed by Anne Simmons, Space Studies Board The National Academies Current Projects Publications Directories Search Site Map Feedback file:///C|/SSB_old_web/an91ch3.htm (20 of 20) [6/18/2004 10:26:44 AM]
