Space Studies Board Annual Report 1995 (1996) / Chapter Skim
Currently Skimming:
3 Summaries of Major Reports
3 Summaries of Major Reports
Pages 31-73
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From page 31... ...
, both in the construction and operations phases. The two 8meter telescopes of the international Gemini 8-M Telescopes Project (IGP)
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From page 32... ...
Independent observatories would be able to compete for these grants, which would be awarded strictly on the basis of scientific merit, but for which cost sharing, in the form of open access to the astronomical community at large, would be a requirement. Such a program would enable full utilization of the enormous investment in both federal and nonfederal capital in OIR telescopes.
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From page 33... ...
It assessed the scientific and technological underpinnings of the materials processing in space program and provided a clear understanding of the potential for exploitation of the space environment for processing materials. · Space Science in the Twenty-First Century: Imperatives for the Decades 1995 to 2015.
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From page 34... ...
The purpose of this report is to recommend means to accomplish that goal. The essential features of the recommendations are to emphasize microgravity research for its general scientific and technological value, as well as its role in advancing technology for the exploration of space; to Reemphasize the research value of manufacturing in space with the intent of returning products to Earth; to modify NASA's infrastructure, policy, and procedures so as to facilitate laboratory science in space; to establish priorities for microgravity experimentation in scientific disciplines and subdisciplines in accordance with the relative opportunities for scientific and technological impact; and to recognize fluid mechanics and transport phenomena as a central theme throughout microgravity research.
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· Fluid mechanics and transport phenomena represent both a distinct discipline and a scientific theme that impacts nearly all microgravity research experiments. · The ground-based research program is critically important for the preparation and definition of the flight program.
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Fluid Mechanics and Transport Phenomena Fluid mechanics and transport phenomena play a dual role in the microgravity research program. They stand as distinct disciplinary areas but also appear as themes running through other disciplines.
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Clearly, fluids and transport phenomena appear as critical technical issues in many spaceflight-enabling technologies. Combustion Combustion involves fluid mechanics, mass and heat transport, and chemical reaction all directly or indirectly subject to numerous gravitational effects.
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From page 38... ...
Materials Science and Processing Metals and Alloys. The microgravity environment provided by an orbiting spacecraft offers new opportunities in the control of melting and solidification processes.
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The microgravity environment will be particularly useful for the study of transport phenomena in the liquids from which bulk crystals are grown, and priority should be given to these studies rather than to the growth of large crystals. Such studies probably require a steady, very-low-gravity environment such as that obtainable in a free-flyer and will provide useful data without requiring growth of bulk crystals.
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From page 40... ...
Given the long time scale for the ground-based development through flight of a space experiment, there is concern that the scientific goals of the experiment might be bypassed by new developments or by major shifts in the value ascribed
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On both the space shuttle and the space station, only a few experiments will be located close enough to the center of mass to ensure acceleration levels below the 10-6-g level. · A number of scientifically meritorious projects, such as the equivalence principle experiment and GPB, will require spaceflight independent of any manned space facilities.
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From page 42... ...
The present microgravity research infrastructure does not readily accommodate the needs of laboratory research. Although drop towers and airplanes flying parabolic trajectories can be used for special or precursor experiments and some materials processing can be done on free-flyers, the spacelab and space station are better suited for microgravity laboratory research.
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From page 43... ...
The biotechnology program has been affected by some confusion concerning its administrative oversight. Biotechnology is tied strongly to other microgravity programs because it shares fluids and transport phenomena as the common scientific theme through which gravity becomes an important parameter.
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From page 44... ...
This archive should contain a bibliography of all published scientific papers and reports on microgravity subjects and should preserve the original spaceflight data sets, such as photographs and electronically recorded data. An additional point of concern is that given the long time scale for the development through flight of a space experiment, there is a real danger that the scientific goals of the experiment might be bypassed by new developments or by major shifts in the value ascribed to the work.
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From page 45... ...
Since then the funding has been approximately $50 M/yr. When the project was last reviewed for NASA 4 years ago, the Parker Committee, an ad hoc review committee convened by NASA Associate Administrator for Space Science and Applications Lennard A
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From page 46... ...
A 1 percent measurement of the predicted frame-dragging effect would be a significant and unique test of GR. Gravity Probe B is one of the few space missions NASA has conducted with relevance to fundamental physics.
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From page 47... ...
The task group notes that in any event, should the GP-B experiment be completed successfully but yield results different from those predicted by general relativity, the scientific world would almost certainly not be prepared to accept them until confirmed by a repeat mission using GP-B backup hardware, or by a new mission using different technology. Comparison with Other Proposed Programs O ~ The scientific objectives of GP-B involve testing one of the fundamental laws of nature.
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From page 48... ...
48 Space Studies Board Annual Report 1995 Consequently, the task group's members hold a range of opinions on the relative cost-effectiveness of GP-B. A significant minority judge that the purpose of the mission is too narrow in comparison with missions that explore wide-open scientific issues and have a high probability of making new discoveries.
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From page 49... ...
organizational issues in the conduct of civil earth observations programs. Following the body of the report is a series of appendixes: after a list of acronyms and abbreviations and collected short biographies of CES members, six brief tutorials discuss several scientific topics important to the science and applications of earth observations.
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From page 50... ...
The MTPE was allied early with the Space Station program. As a result of that tie, the program took the initial form of a satellite design using very large, highly complex, astronaut-tended, polar platforms that would be serviced from the Space Shuttle, which was required to fly in a polar orbit for this purpose.
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From page 51... ...
is hampered by the number of agencies and budget processes involved. APPLICATIONS PROGRAMS Advancing the operational utility of civil earth observations has not been given national priority in the current efforts.
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This information is also required to improve understanding of various earth sciences meteorology, oceanography, geology, and geophysics. Not only practical applications of substantial economic importance but also the advance of earth-oriented science are inhibited by the inadequacies of this sector of the space program.
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From page 53... ...
Furthermore, the CES sees no pressing need within the domain of civil earth observations to fly satellites as a management demonstration simply to prove that small, modestly capable satellites can be launched quickly. Well-crafted experimental technology satellites, however, can serve as engineering testbeds to qualify new subsystems for later use in research and operational observation systems; but such testbeds are quite likely to be of a different character than satellites intended to observe long-term changes in climate variables.
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From page 54... ...
Finally, the next generation of earth scientists, the graduate students in universities, are often educated by performing research that has originated in R&A efforts. THE ORGANIZATION OF CIVIL EARTH OBSERVATIONS PROGRAMS As noted above, the United States is funding a variety of experimental and operational earth observations programs.
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1986. Issues and Recommendations Associated with Distributed Computation and Data Management Systems for the Space Sciences, National Academy Press, Washington, D.C.
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1988a. Space Science in the Twenty-First Century, Imperativesfor the Decades 1995 to 2015, Mission to Planet Earth, Task Group on Earth Sciences, National Academy Press, Washington, D.C.
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Not all of the events of recent years have been detrimental for space science. The decline in superpower rivalries has opened new avenues for international cooperation.
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The obvious deficiency in the instrument package is the absence of an optical framing camera of astronomical quality. The addition of such an instrument would have a very significant impact on the astronomical capabilities of the ATD/NTOT.
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From page 59... ...
orbit; · Investigation of the stability of field distortions, particularly as the figure of the primary mirror responds to its control actuators and, also, as the fast-steering mirror stabilizes the telescope's line of sight; · Exploitation of the ATD/NTOT' s agility and large fuel reserves to actively maneuver the spacecraft so that it is in the right place, at the right time, to observe ephemeral events such as occultations; · Exploration of the possibilities presented by the Molniya orbit to conduct very long integrations in a costeffective manner; and · Utilization of the facility as an experimental teethed for various modes of ground operations that may be needed for future space science missions. The implementation of some of the task group's suggested enhancements to the baseline ATD/NTOT would significantly improve the evaluation of both the technology and the astronomical significance of a program of technology demonstrations.
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From page 60... ...
· The effect of cosmic-ray events on the ATD/NTOT's imaging arrays when the spacecraft is operating in the highly eccentric Molniya orbit is a significant factor. · Although building to cost is becoming a key feature of NASA's present and future missions, neither NASA nor the space science community has much experience with this mode of operation.
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From page 61... ...
A complete adaptive-optics system and examples of thin primary mirrors, for instance, currently sit gathering dust in testing chambers. Many of these subsystems are themselves interesting additions to the tools at the disposal of astronomers and may find scientific applications very different from those for which they were designed.
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From page 62... ...
1-4. fin this report, "space sciences" refers to all of NASA's science programs conducted in or from space, including space astronomy, space physics, planetary exploration, microgravity research, space life sciences, and Earth science.
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From page 63... ...
The committee reviewed the advantages and disadvantages of such a model and concluded that the NIH model, while effective in the arena of health research, is not appropriate for the space sciences. NASA space science benefits from close coordination with other elements of NASA, such as hardware development, launch services, and tracking and data operations, which have no counterparts in the NIH model.
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The NASA space science programs, from the dawn of the space age to the present, have produced an unprecedented flow of discoveries. The fiscal, political, and technological environment of the agency is now in a state of rapid change.
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With an assured, steady stream of small missions, occasional failures become, if not acceptable, at least tolerable. Since early in the space program, NASA's astrophysics and space physics programs have built and flown a highly effective series of Explorer spacecraft.
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From page 66... ...
These include the following: A continuing budget line should be initiated that is dedicated to a series of small planetary missions that focus on specific, well-defined objectives and are capable of yielding significant scientific results. The chosen missions should address key scientific questions and objectives as outlined in the report An Integrated Strategy for the Planetary Sciences: 1995-2010.
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From page 67... ...
The task group proceeded from the principle that the central criterion for evaluating a research initiative must be its scientific merit the value of the initiative to the proposing discipline and to science generally. But because space research initiatives are supported by public funds, other key criteria include the expected contribution to national goals (including the enhancement of human understanding)
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From page 68... ...
It has become a "hard" science, focusing on understanding the fundamental interactions between charged particles, electromagnetic fields, and gases in the natural laboratory consisting of the galaxy, the Sun, the heliosphere, and planetary magnetospheres, ionospheres, and upper atmospheres. The motivation for space physics research goes far beyond basic physics and intellectual curiosity, however, because long-term variations in the brightness of the Sun vitally affect the habitability of the Earth, while sudden rearrangements of magnetic fields above the solar surface can have profound effects on the delicate balance of the forces that shape our environment in space and on the human technology that is sensitive to that balance.
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From page 69... ...
At least at the solar surface, and perhaps in the interior as well, the magnetic fields are confined to rope-like structures with diameters of about 100 km, which are too small to be resolved from Earth. It has been suggested that the twisting and shearing of these flux tubes lead to bursts of high-speed solar wind, called coronal mass ejections, and to solar flares, but the trigger mechanisms for those violent events are not yet known.
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From page 70... ...
The following priorities are identified for future research on the solar wind and the heliosphere: · Continue to obtain and synthesize the data from the present constellation of heliospheric spacecraft and from the interplanetary cruise phases of planetary missions in order to characterize the global and solar-cycle-dependent properties of the heliosphere and its interactions with the interstellar medium. · Carry out in situ observations of the solar corona to explore and characterize the region of acceleration of the solar wind and the physical processes responsible for that acceleration.
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From page 71... ...
· Maintain the full complement of particle and field instruments on current and future planetary missions to gain increased understanding of the formation and dynamics of diverse magnetospheres and ionospheres. · Further develop and exploit ground-based facilities that image the ionospheric manifestations or "footpoints" of solar wind/magnetosphere coupling processes to complement the magnetospheric imaging initiative aimed at studying the global properties of the magnetosphere.
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From page 72... ...
RECOMMENDED RESEARCH EMPHASES The specific programs required to obtain answers to the questions raised under each of the five key topics outlined above are quite different. However, they are united by four common elements or themes that the CSSP and CSTR consider to be the most important research emphases for space physics in the next decade.
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From page 73... ...
Special emphasis should be given to the following topics: · Designing a new generation of instrumentation for remote global imaging of magnetospheric, ionospheric, and solar wind plasmas; · Recognizing that synergy between observations, modeling, and theory provides the optimum way of addressing the principal questions in space physics; · Making numerical simulations of space physics systems more realistic by extending them to three dimensions, longer time durations, and a greater range of scale sizes, and by incorporating additional physical and chemical processes; · Ensuring access to state-of-the-art computational facilities; · Exploiting new insights gained from theory, especially the theory of nonlinear processes; and · Revisiting earlier efforts to predict solar activity, such as coronal mass ejections and flares, using simulations combined with solar observations.
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