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Toward a Microgravity Research Strategy Toward a Microgravity Research Strategy NOTICE MEMBERSHIP SUMMARY CHAPTER 1 CHAPTER 2 CHAPTER 3 Committee on Microgravity Research CHAPTER 4 Space Studies Board APPENDIX A Commission on Physical Sciences, APPENDIX B Mathematics, and Applications APPENDIX C APPENDIX D National Research Council APPENDIX E APPENDIX F NOTICE MEMBERSHIP SUMMARY AND RECOMMENDATIONS file:///C|/SSB_old_web/cmgr92menu.htm (1 of 3) [6/18/2004 11:07:17 AM]

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Toward a Microgravity Research Strategy Introduction Nature of the Field Status of the Field The Conduct of Microgravity Research Conclusions and Recommendations References 1. OVERVIEW OF MICROGRAVITY RESEARCH Examples of Microgravity Experiments Reference 2. STATUS OF THE FIELD References 3. THE CONDUCT OF MICROGRAVITY RESEARCH Instrumentation Manned Versus Robotic Interaction Range of Microgravity Facilities Microgravity Research Outside the United States Commercial Programs The Research and Analysis Program References 4. TOWARD THE DEVELOPMENT OF A RESEARCH STRATEGY APPENDIXES A. Biological Sciences B. Combustion Science C. Electronic Materials D. Fluids, Interfaces, and Transport E. Glasses and Ceramics F. Metals and Alloys NATIONAL ACADEMY PRESS, 1992 file:///C|/SSB_old_web/cmgr92menu.htm (2 of 3) [6/18/2004 11:07:17 AM]

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Toward a Microgravity Research Strategy (Notice) Toward a Microgravity Research Strategy NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The National Academy of Sciences is a private, nonprofit, self- perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Frank Press is president of the National Academy of Sciences. REPORT MENU The National Academy of Engineering was established in 1964, under the NOTICE charter of the National Academy of Sciences, as a parallel organization of MEMBERSHIP outstanding engineers. It is autonomous in its administration and in the selection SUMMARY of its members, sharing with the National Academy of Sciences the responsibility CHAPTER 1 for advising the federal government. The National Academy of Engineering also CHAPTER 2 sponsors engineering programs aimed at meeting national needs, encourages CHAPTER 3 education and research, and recognizes the superior achievements of engineers. CHAPTER 4 Dr. Robert M. White is president of the National Academy of Engineering. APPENDIX A APPENDIX B The Institute of Medicine was established in 1970 by the National APPENDIX C Academy of Sciences to secure the services of eminent members of appropriate APPENDIX D professions in the examination of policy matters pertaining to the health of the APPENDIX E public. The Institute acts under the responsibility given to the National Academy APPENDIX F of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology file:///C|/SSB_old_web/cmgr92notice.htm (1 of 3) [6/18/2004 11:07:22 AM]

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Toward a Microgravity Research Strategy (Notice) with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Frank Press and Dr. Robert M. White are chairman and vice chairman, respectively, of the National Research Council. Support for this project was provided by Contract NASW 4627 between the National Academy of Sciences and the National Aeronautics and Space Administration. Copies of this report are available from Space Studies Board National Research Council 2101 Constitution Avenue, N.W. Washington, D.C. 20418 Printed in the United States of America file:///C|/SSB_old_web/cmgr92notice.htm (2 of 3) [6/18/2004 11:07:22 AM]

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Toward a Microgravity Research Strategy (Membership) Toward a Microgravity Research Strategy Membership COMMITTEE ON MICROGRAVITY RESEARCH ROBERT F. SEKERKA,* Carnegie Mellon University, Chairman ROBERT A. BROWN, Massachusetts Institute of Technology FRANKLIN D. LEMKEY, United Technologies Research Center WILLIAM A. SIRIGNANO, University of California, Irvine THOMAS A. STEITZ, The Howard Hughes Medical Institute Space Studies Board Member (July 1989 to June 1991) JOHN R. CARRUTHERS Space Studies Board Staff REPORT MENU JOYCE M. PURCELL, Executive Secretary NOTICE MELANIE M. GREEN, Administrative Secretary MEMBERSHIP CARMELA J. CHAMBERLAIN, Administrative Secretary SUMMARY CHAPTER 1 CHAPTER 2 _____________________ CHAPTER 3 *Member, Space Studies Board, July 1989 to June 1992. CHAPTER 4 APPENDIX A APPENDIX B APPENDIX C APPENDIX D SPACE STUDIES BOARD APPENDIX E APPENDIX F LOUIS J. LANZEROTTI, AT&T Bell Laboratories, Chairman JOSEPH A. BURNS, Cornell University ANDREA K. DUPREE, Harvard-Smithsonian Center for Astrophysics JOHN A. DUTTON, Pennsylvania State University LARRY W. ESPOSITO, University of Colorado, Boulder JAMES P. FERRIS, Rensselaer Polytechnic Institute HERBERT FRIEDMAN, Naval Research Laboratory (retired) RICHARD L. GARWIN, IBM T.J. Watson Research Center file:///C|/SSB_old_web/cmgr92mem.htm (1 of 3) [6/18/2004 11:07:26 AM]

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Toward a Microgravity Research Strategy (Membership) RICCARDO GIACCONI, Space Telescope Science Institute NOEL W. HINNERS, Martin Marietta Civil Space and Communications Company JAMES R. HOUCK, Cornell University DAVID A. LANDGREBE, Purdue University RICHARD S. LINDZEN, Massachusetts Institute of Technology JOHN H. McELROY, University of Texas at Arlington WILLIAM J. MERRELL, JR., Texas A&M University RICHARD K. MOORE, University of Kansas ROBERT H. MOSER, The NutraSweet Company NORMAN F. NESS, University of Delaware MARCIA NEUGEBAUER, Jet Propulsion Laboratory MARK SETTLE, ARCO Oil and Gas Company WILLIAM A. SIRIGNANO, University of California, Irvine FRED TUREK, Northwestern University ARTHUR B.C. WALKER, Stanford University MARC S. ALLEN, Director COMMISSION ON PHYSICAL SCIENCES, MATHEMATICS, AND APPLICATIONS NORMAN HACKERMAN, Robert A. Welch Foundation, Chairman PETER J. BICKEL, University of California at Berkeley GEORGE F. CARRIER, Harvard University GEORGE W. CLARK, Massachusetts Institute of Technology DEAN E. EASTMAN, IBM T.J. Watson Research Center MARYE ANNE FOX, University of Texas PHILLIP A. GRIFFITHS, Institute for Advanced Studies NEAL F. LANE, Rice University ROBERT W. LUCKY, AT&T Bell Laboratories CLAIRE E. MAX, Lawrence Livermore Laboratory CHRISTOPHER F. McKEE, University of California at Berkeley JAMES W. MITCHELL, AT&T Bell Laboratories RICHARD S. NICHOLSON, American Association for the Advancement of Science ALAN SCHRIESHEIM, Argonne National Laboratory KENNETH G. WILSON, Ohio State University NORMAN METZGER, Executive Director file:///C|/SSB_old_web/cmgr92mem.htm (2 of 3) [6/18/2004 11:07:26 AM]

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Toward a Microgravity Research Strategy (Summary and Recommendations) Toward a Microgravity Research Strategy Summary and Recommendations INTRODUCTION As part of a self-assessment and subsequent reorganization in 1989, the Space Studies Board (SSB) created a new standing committee—the Committee on Microgravity Research (CMGR). The formation of the committee was due, in part, to the dissolution of the National Research Council's (NRC's) Space Applications Board, which, until 1988, held the NRC's advisory responsibility for microgravity issues. Over the course of the past 20 years, the Space Studies Board has, through its standing discipline committees, developed and published a series of research strategies for each of the major space research disciplines. These strategies are meant to serve as guides for the National Aeronautics and Space Administration (NASA) in planning its space research program. As one of its charges, the CMGR was asked by the SSB ". . . to conduct a study on the REPORT MENU maturity and state of readiness of the field for the development of a NOTICE comprehensive long-range research strategy." MEMBERSHIP SUMMARY In this report to the SSB, the CMGR finds that the various subdisciplines CHAPTER 1 of the field are heterogeneous in both their nature and state of maturity. This is CHAPTER 2 reflected in Appendixes A to F, which briefly discuss the status, CHAPTER 3 accomplishments, and prospects and opportunities for each microgravity CHAPTER 4 research subdiscipline. Notwithstanding this inherent heterogeneity, the APPENDIX A CMGR concludes that the field as a whole would benefit from the APPENDIX B formulation of a long-range research strategy and that such a strategy APPENDIX C should be developed as soon as possible. APPENDIX D APPENDIX E APPENDIX F NATURE OF THE FIELD Microgravity research encompasses scientific investigation conducted in a gravitational field (or equivalent acceleration with respect to an inertial frame) that is a small fraction of the gravitational acceleration on Earth. The role of gravity in physical phenomena is uniquely important in a limited set of circumstances, file:///C|/SSB_old_web/cmgr92summary.htm (1 of 8) [6/18/2004 11:07:32 AM]

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Toward a Microgravity Research Strategy (Summary and Recommendations) including the following: 1. As a driving force for convection in fluids, 2. As a driving force for phase separation, 3. As a force that helps to determine the free surface morphology of fluids, 4. Near a critical point, 5. In the presence of very weak binding forces, 6. In the presence of very large masses or for very long times, and 7. In structural members or over large distances. To date, most microgravity experiments have been focused on exploring the first two roles above. These experiments have included studies of crystal growth in fluids, fundamental phenomena in crystal growth, convection phenomena, measurement of the transport properties of fluids, combustion phenomena, fire safety aboard spacecraft, and immiscible alloys and multiphase solids. STATUS OF THE FIELD Between 1989 and 1991, the CMGR reviewed the status of microgravity research, the activities of NASA's Microgravity Science and Applications Division, and previous studies such as Materials Processing in Space,1 Microgravity Science and Applications,2 Review of Microgravity Science and Applications Flight Programs—January-March 1987,3 and Fluid Sciences and Materials Science in Space—a European Perspective.4 Based on this review, the CMGR reached the following conclusions. Fluids, interfaces, and transport; metals and alloys; and combustion science are more developed than the other subdisciplines of the field. The biological sciences category shows promise in the area of protein crystal growth, but little in other aspects such as electrophoresis. Current research holds out little hope for explaining why protein crystals grow differently in space or how to exploit the differences. Excellent-although only a few experiments are planned in the subdiscipline of fundamental processes. Recommendations for future experiments in this direction are more likely to be derived from unsolicited proposals than from Announcements of Opportunity (AOs) issued by NASA. Research in the area of electronic materials has concentrated on bulk materials file:///C|/SSB_old_web/cmgr92summary.htm (2 of 8) [6/18/2004 11:07:32 AM]

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Toward a Microgravity Research Strategy (Summary and Recommendations) thus far. There is some indication that these experiments will produce information of scientific importance. However, concentration on bulk materials is contrary to the mainstream of the field, which emphasizes research on the properties of thin films deposited on substrates rather than research on electronic properties. Current research on the qualities of bulk crystals (when used as substrates) suggests that such crystals may hold some practical value. The subdiscipline of glasses and ceramics is relatively undeveloped at present; some research in this area overlaps with research in metals and alloys. It should be recognized that microgravity research is a relatively new and laboratory-intensive field that requires frequent access to space. So far, progress has been limited considerably by the paucity of flight opportunities. THE CONDUCT OF MICROGRAVITY RESEARCH Microgravity research must be performed in an environment far from Earth and, therefore, is largely inaccessible. In addition, it is extremely expensive, both in terms of the initial investment and in operating costs, particularly when humans are involved. The conduct tit microgravity research requires the development of scientific equipment that is capable of withstanding the stresses of launch and reentry and of functioning reliably and safely in space. The interaction of users with this equipment is quite different from their interaction with other space instruments. Often, the users of microgravity equipment must change experimental parameters from run to run of an experiment. A more efficient approach to designing and building equipment would be to provide instrumentation that is specific to the experiment or class of experiments and that is designed and built in close cooperation with the principal investigator(s). This would be a departure from current practice, in which equipment is developed for a broad population of users. Microgravity experiments can be carried out in a variety of modes, ranging from continuous human intervention to full automation. An optimum microgravity research program would use a mixture of modes, depending on the set of experiments to be performed, the state of the technology, and cost- effectiveness. Some microgravity experiments require a manned, space-based laboratory (such as a space station), while others can be done well or better, and at a much lower cost, by other means such as in satellites, rockets, and drop towers. A wide range of facilities—from ground-based drop tubes to the complex facilities of the Shuttle-based Spacelab—can provide microgravity conditions. An experimenter's choice of facility should be based on specific research needs as well as cost. file:///C|/SSB_old_web/cmgr92summary.htm (3 of 8) [6/18/2004 11:07:32 AM]

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Toward a Microgravity Research Strategy (Summary and Recommendations) CONCLUSIONS AND RECOMMENDATIONS Development of a Research Strategy The Committee on Microgravity Research recommends that a long- term research strategy, such as that developed by the Space Studies Board's other discipline committees, be developed for microgravity science. In addition to defining the overall goals of the microgravity science field and summarizing the current knowledge of its subdisciplines, this strategy should identify the fundamental questions that need to be addressed and the scientific community's ability to address them. Consideration should be given to all modes of doing this type of research, with attention to maximizing experimental return and minimizing cost. The primary objectives defined should be ranked in order of priority and should be accompanied by the criteria used to determine their priority. Critical components necessary to support a successful microgravity research program should be described and appropriate measurement indicators developed. Microgravity Research Versus Materials Processing It should be recognized that, to date, no examples have been found of materials that are worthy of manufacture in space. Unless and until such examples are found, space manufacturing of products to be used on earth should be deemphasized as a reason for undertaking microgravity research. The descriptor "materials processing" is misleading and should be eliminated. The CMGR recommends that "microgravity research" be used instead. The main rationale for the microgravity research program should be to improve our fundamental scientific and technological knowledge base, particularly in areas that are likely to lead to improvements in processing and manufacturing on Earth. A secondary rationale should be to develop the technologies for handling materials in space and possibly for processing materials to be used in space. Subdivisions for Microgravity Research Microgravity research encompasses a wide range of subdisciplines. NASA's Microgravity Science and Applications Division and its advisory groups are currently divided into seven "disciplines": biological sciences; combustion science; electronic materials; fluids, interfaces, and transport; fundamental processes; glasses and ceramics; and metals and alloys. After careful consideration, the Committee on Microgravity Research as file:///C|/SSB_old_web/cmgr92summary.htm (4 of 8) [6/18/2004 11:07:32 AM]

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Toward a Microgravity Research Strategy (Summary and Recommendations) concluded that the current subdivisions of microgravity science should be revised. The CMGR recommends that microgravity research be reorganized into six categories that reflect future opportunities more realistically, including: Biological science and technology, Combustion, Fluid science, Fundamental phenomena, Materials, and Processing science and technology. Conduct and Support of the Research and Analysis Program A thorough program of ground-based research should precede and follow every microgravity flight. When exemplary materials are produced in microgravity, attempts should be made to replicate them using ground-based research. In addition, much more effort should be made to model phenomena suggested by microgravity observations. Research projects include both focused opportunities advertised through AOs issued by NASA and unsolicited proposals submitted to NASA. The research and analysis program in NASA's Microgravity Science and Applications Division consists of the ground-based research needed to provide the context of knowledge from which the flight program originates as well as the infrastructure required to analyze microgravity experiments in a broader context. If microgravity research is to develop into a mature field, the current research program should be reconstituted and refocused in order to improve its health and to provide new opportunities. The CMGR recommends that NASA apply a set of value criteria and measurement indicators to define the research and analysis program more clearly. These value criteria and indicators should be compared with other areas of physical and chemical sciences to calibrate funding levels with research output over a reasonable period of time (such as three years). If research of higher quality and wider diversity is to be incorporated into the microgravity research program, it is imperative that the research and analysis budget be a larger fraction of the total microgravity budget. The CMGR recommends that the funding level for research and analysis in file:///C|/SSB_old_web/cmgr92summary.htm (5 of 8) [6/18/2004 11:07:32 AM]

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Toward a Microgravity Research Strategy (Summary and Recommendations) microgravity science be established as a fixed percentage of the total program of NASA's Microgravity Science and Applications Division in order to build a strong scientific base for future experiments. Content of the Program and Facilities Materials employed in microgravity environments should be characterized thoroughly before and after flight. The thermophysical data needed to interpret experiments should be measured as a part of the program if they arc not available in the literature. Contemporary interest in electronic materials focuses on thin films. Bulk electronic materials are of secondary importance and should be studied in microgravity only to the extent that they will yield fundamental knowledge about processing. When promising results have been obtained, experiments should be repeated to examine their reproducibility; in particular, experiments should be designed and conducted to learn why microgravity makes a measurable difference. Experiments should be analyzed and classified according to their minimum facility requirements so that they can be carried out in the most cost- effective manner. The committee recommends that a concerted effort also be made to classify experiments according to their minimum needs in order that the most cost-effective access to reduced gravity will be used. Equipment to accomplish specific experiments should be designed and built in close cooperation with the principal investigator(s). The acceleration vector environment must be measured accurately, locally, frequently, and synchronously with every experiment. These data should be provided to the principal investigators immediately. Whenever exemplary materials are produced in microgravity, considerable effort should be exerted to replicate them in ground- based research. Commercial Programs In addition to the activities financed by NASA's Microgravity Science and Applications Division, NASA funds commercial microgravity research through its Office of Commercial Programs. This office provides incentives for space experiments and, in cooperation with industry, has established centers for the commercial development of space (CODS) at several universities. Started in 1986, these centers were given five years in which to become independent through increased industrial funding. The CMGR recommends that a thorough technical review of the centers for commercial development of space be conducted to determine the quality of their activities and to ascertain to what degree their original mission has been accomplished. file:///C|/SSB_old_web/cmgr92summary.htm (6 of 8) [6/18/2004 11:07:32 AM]

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Toward a Microgravity Research Strategy (Summary and Recommendations) REFERENCES 1. Committee on Scientific and Technological Aspects of Materials Processing in Space, Space Applications Board. 1978. Materials Processing in Space. National Academy of Sciences, Washington, D.C. 2. Solid State Sciences Committee, Board on Physics and Astronomy. 1986. Microgravity Science and Applications: Report on a Workshop. National Academy Press, Washington, D.C. 3. Review Committee, J. Robert Shrieffer, chairman. 1987. Review of Microgravity Science and Applications Flight Programs—January-March 1987. Universities Space Research Association, Washington, D.C. 4. European Space Agency. 1987. Fluid Sciences and Materials Science in Space—a European Perspective. Springer-Verlag. file:///C|/SSB_old_web/cmgr92summary.htm (7 of 8) [6/18/2004 11:07:32 AM]