The Decade of Discovery in Astronomy and Astrophysics (1991) / Chapter Skim
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1. Recommendations
1. Recommendations
Pages 8-27
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From page 8... ...
1 Recommendations INTRODUCTION Our Place in the Universe Astronomy and astrophysics address questions about the origin and evolution of the planets, the stars, and the universe. In this century we have learned that the climates and weather patterns of planets in the solar system are driven by many of the same physical processes that create the earth's environment; that stars form out of clouds of gas and eventually die either in quiet solitude or spectacular explosions; that most of the common chemical elements are created in explosions of stars; that stars group together in isolated galaxies; that galaxies and clusters of galaxies stretch in sheets and filaments as far as the largest telescopes can see; and that the universe itself was born in a violent explosion some 15 billion years ago.
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· Increasing evidence suggested the possibility of giant black holes in the centers of some galaxies and quasars. · An orbiting satellite surveyed the sky at infrared wavelengths and discovered disks of solid material, possibly the remnants of planet formation, orbiting nearby stars.
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New radio telescopes will reveal previously invisible details at millimeter and submillimeter wavelengths. A technique called interferometry will combine optical or infrared light from different telescopes separated by hundreds of meters to make images thousands of times sharper than can be achieved with a single telescope.
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From page 11... ...
In forming its judgment of scientific importance, the committee also took into account cost-effectiveness, technological readiness, educational impact, and the relation of each project to existing or proposed initiatives in the United States and in other countries. In a letter to the committee commenting on the initial charge, NASA's associate administrator for space science pointed out that NASA's solar physics research program contains investigations of the sun viewed both as a star and as a power source for the solar system, and that many of NASA's solar physics missions have a strong coupling to in situ measurements, which lie outside the purview of this committee.
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Appendix C lists the scientists who served on the panels established by the committee to help carry out this decennial survey. RECOMMENDATIONS FOR STRENGTHENING GROUND-BASED INFRASTRUCTURE · The highest priority of the survey committee for groundbased astronomy is the strengthening of the infrastructure for research, that is, increased support for individual research grants
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by a factor of 10, provide needed computational resources to deal with largeformat arrays of optical and infrared detectors at NOAO, replace antiquated equipment at the National Astronomy and Ionosphere Center (NAIC) , and hire new technical staff to service millimeter receivers, infrared arrays, and advanced optics.
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The recommended annual increase for the grants program is meant to accomplish three purposes: first, improve the chances for first-time applicants, many of whom are young scientists with no other means of research support, to receive grants ($1.5 million per year) ; second, increase the average grant size by $20,000 to a total of $80,000, which is approximately the size needed to support and train an individual postdoctoral fellow ($7.5 million per year)
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In Chapter 7, the committee describes its view that a strong involvement by scientists is critical to the success of space projects of all sizes. This committee has reexamined the justification for large-scale space astronomy programs, taking into account both the failure to meet specifications in the HST program and NASA's record of successes in carrying out other complex missions at the frontiers of science and technology.
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SIRTF has superb science potential, is technologically well developed, and has been preceded by two smaller and successful precursor missions. RECOMMENDED NEW EQUIPMENT INITIATIVES Ground and Space Initiatives · The Astronomy and Astrophysics Survey Committee recommends the approval and funding of the set of new equipment initiatives listed in Table 1.1.
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15 International collaborations 32 on space instruments 70 230 400 250 100 Subtotal ground-based 172 Subtotal space-based 1,050 Illustrative Small Programsb Two-micron survey 5 Small Explorer acceleration 100 infrared instruments 10 Orbiting planetary telescope 50 Cosmic background imager 7 VSOP/RadioAstron 10 Laboratory astrophysics 10 Laboratory astrophysics 20 National astrometric facility 10 300-m antenna in Brazil 10 Stellar oscillations instrument 3 Optical surveys 6 Neutrino supernova watch 10 Subtotal ground-based 71 Total ground-based 493 DECADE TOTAL Subtotal space-based 180 Total space-based 2,530 3,023 aExamples include gamma-ray spectroscopy, submillimeter spectroscopy, and x-ray imaging. b three small ground-based programs and one space initiative are highlighted by italics since they were regarded by the committee as being of special scientific importance.
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The committee stresses that progress in astronomy requires a vigorous program of theoretical research and laboratory astrophysics, as well as a balanced program of observation. The vital roles of theory and of laboratory astrophysics are discussed further in Chapter 3.
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Large Programs Space Infrared Telescope Facility (SIRTF) Infrared-optimized 8-m telescope Millimeter Array (MMA)
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The highest-priority recommendation for a large ground-based facility is for the construction of an 8-m-diameter telescope on Mauna Kea, Hawaii; this telescope and its instrumentation should be optimized for low-background, diffraction-limited operation at infrared wavelengths from 2 to 10 ~m. The planned telescope will be a unique facility, using revolutionary infrared array detectors to make high-spatial- and high-spectralresolution observations of objects as various as volcanoes on the satellite lo, the inner parts of protoplanetary disks around nearby young stars, and distant galaxies.
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The technical heritage of SIRTF includes two infrared telescopes launched and successfully operated as part of NASA's Explorer program. MODERATE PROGRAMS Ground-based Projects Adaptive Optics and Interferometry.
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While discovery often follows the opening of new frontiers in sensitivity, wavelength, or angular resolution, detailed understanding usually requires detective work by large numbers of scientists with access to appropriate investigative tools. The basic "detective tool" for standard investigations in the 1990s will be a 4-m-class optical or infrared telescope.
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Space-based Projects Dedicated Spacecraft for FUSE. The committee recommends that NASA augment the Explorer program sufficiently to convert the Far Ultraviolet Spectroscopy Explorer into a Delta-launched experiment using its own dedicated spacecraft.
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A budget line for international collaborations will allow NASA to undertake more of these advantageous joint ventures. SMALL PROGRAMS Small programs can be carried out relatively quickly in response to new scientific or technological developments, focusing research into the currently most profitable areas and making possible greater participation by young astronomers.
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Other space projects that will return important data at relatively low cost include U.S. participation in a German orbiting planetary telescope, and orbiting very long baseline interferometry (VLBI)
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As discussed in Chapter 5, the archiving of these data is a high scientific priority. Developments in three areas have particularly great potential to enhance the efficiency of radio telescopes: low-noise receivers for millimeter and submillimeter wavelengths, broad-bandwidth recording systems and data links for VLBI, and focal plane arrays.
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One example of a next-generation space observatory is a large space telescope, a 6-m telescope that would combine the light-gathering power of a large ground-based telescope with the excellent image quality, ultraviolet capability, and low-infrared background that are achievable in space. Other possible missions with great scientific potential include a large x-ray telescope equipped with detectors capable of simultaneous imaging and spectroscopy; a submillimeter observatory consisting of a deployable 10-m telescope or an orbiting array of smaller telescopes operating as an interferometer; a single large radio telescope many kilometers across; and five orbiting radio telescopes of 100-m diameter forming an array that surrounds the earth.
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