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At least 127 records · Page 7

High energy gamma ray astronomy

High energy gamma ray astronomy has evolved with the space age. Nonexistent twenty-five years ago, there is now a general sketch of the gamma ray sky which should develop into a detailed picture with the results expected to be forthcoming over the next decade. The galactic plane is the dominant feature of the gamma ray sky, the longitude and latitude distribution being generally correlated with galactic structural features including the spiral arms. Two molecular clouds were already seen. Two of the three strongest gamma ray sources are pulsars. The highly variable X-ray source Cygnus X-3 was seen at one time, but not another in the 100 MeV region, and it was also observed at very high energies. Beyond the Milky Way Galaxy, there is seen a diffuse radiation, whose origin remains uncertain, as well as at least one quasar, 3C 273. Looking to the future, the satellite opportunities for high energy gamma ray astronomy in the near term are the GAMMA-I planned to be launched in late 1987 and the Gamma Ray Observatory, scheduled for launch in 1990. The Gamma Ray Observatory will carry a total of four instruments covering the entire energy range from 30,000 eV to 3 x 10 to the 10th eV with over an order of magnitude increase in sensitivity relative to previous satellite instruments.

Fichtel, Carl E.↗

NASA thesaurus: Astronomy vocabulary

A terminology of descriptors used by the NASA Scientific and Technical information effort to index documents in the area of astronomy is presented. The terms are listed in hierarchical format derived from the 1988 edition of the NASA Thesaurus Volume 1 -- Hierarchical Listing. Over 1600 terms are included. In addition to astronomy, space sciences covered include astrophysics, cosmology, lunar flight and exploration, meteors and meteorites, celestial mechanics, planetary flight and exploration, and planetary science.

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Overview of lunar-based astronomy

The opportunities along with the advantages and disadvantages of the Moon for astronomical observatories are carefully and methodically considered. Taking a relatively unbiased approach, it was concluded that lunar observatories will clearly be a major factor in the future of astronomy in the next century. He concludes that ground based work will continue because of its accessibility and that Earth orbital work will remain useful, primarily for convenience of access in constructing and operating very large space systems. Deep space studies will feature not only probes but extensive systems for extremely long baseline studies at wavelengths from gamma rays through visible and IR out to radio is also a conclusion drawn, along with the consideration that lunar astronomy will have found important permanent applications along lines such as are discussed at the present symposium and others quite unsuspected today.

Smith, Harlan J.↗

Infrared astronomy from the Moon

The Moon offers some remarkable opportunities for performing infrared astronomy. Although the transportation overhead can be expected to be very large compared with that for facilities in Earth orbit, certain aspects of the lunar environment should allow significant simplifications in the design of telescopes with background limited performance, at least in some parts of the thermal infrared spectrum. Why leave the Earth to perform infrared astronomy is addressed as is the reasons for going all the way to the Moon for its environment.

Lester, Dan↗

The decade of discovery in astronomy and astrophysics

A survey of astronomy and astrophysics in the 1990s is presented and a prioritized agenda is offered for space- and ground-based research into the 21st century. In addition to proposing new telescopes for ground and space, the research infrastructure is discussed. The urgent need is emphasized for increased support of individual investigators, for appropriate maintenance and refurbishment of existing facilities, and for a balanced program of space astronomy. The scientific and the technical opportunities of the 1990s are summarized and the technological development is described needed for instruments to be built in the first years of the next century. Also addressed is the suitability of the Moon as an observation site.

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Infrared astronomy takes center stage

Characteristics of infrared astronomy, including the ability to detect cool matter, explore the hidden universe, reveal a wealth of spectral lines, and reach back to the beginning of time are outlined. Ground-based infrared observations such as observations in the thermal infrared region are discussed as well as observations utilizing infrared telescopes aboard NASA aircraft and orbiting telescopes. The Space Infrared Telescope Facility and the Stratospheric Observatory for Infrared Astronomy are described, and it is pointed out that infrared astronomers can penetrate obscuring dust to study stars and interstellar matter throughout the Milky Way galaxy. Application of various infrared instruments to the investigation of stars and planets is emphasized, and focus is placed on the discovery of clouds or disks of particles around mature stars and acquisition of high-resolution spectra of the gaseous and solid materials orbiting on the fringes of the solar system.

Gillett, Frederick C.↗

An evolutionary sequence of low frequency radio astronomy missions

Many concepts for space-based low frequency radio astronomy missions are being developed, ranging from simple single-satellite experiments to large arrays on the far side of the moon. Each concept involves a different tradeoff between the range of scientific questions it can answer and the technical complexity of the experiment. Since complexity largely determines the development time, risk, launch vehicle requirements, cost, and probability of approval, it is important to see where the ability to expand the scientific return justifies a major increase in complexity. An evolutionary series of increasingly capable missions, similar to the series of missions for infrared or X-ray astronomy, is advocated. These would range from inexpensive 'piggy-back' experiments on near-future missions to a dedicated low frequency array in earth orbit (or possibly on the lunar nearside) and eventually to an array on the lunar farside.

Jones, Dayton L.↗

Reports of planetary astronomy, 1991

A collection is presented of summaries designed to provide information about scientific research projects conducted in the Planetary Astronomy Program in 1990 and 1991, and to facilitate communication and coordination among concerned scientists and interested persons in universities, government, and industry. Highlights of recent accomplishments in planetary astronomy are included.

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FUV and EUV spectrographs - Development in the 1980s for astronomy in the 1990s

This is a review of the rapid developments of the technology for spectrographs to support the unique and difficult requirements of FUV and EUV astronomy. During the 1980's a variety of novel techniques have been incorporated into instrument designs that will collect data in the 1990's. This review summarizes the progress these spectrographs will allow, highlights the challenges that FUV and EUV astronomy will present for the following generation of observatory design, and discusses some of the possible routes to overcoming those challenges.

Cash, W.↗

NASA's future plans for space astronomy and astrophysics

NASA's plans in the field of space astronomy and astrophysics through the first decade of the next century are reviewed with reference to specific missions and mission concepts. The missions discussed include the Space Infrared Telescope Facility, the Stratospheric Observatory for Infrared Astronomy, the Submillimeter Intermediate Mission, the Astrometric Interferometry Mission, the Greater Observatories program, and Mission from Planet Earth. Plans to develop optics and sensors technology to enable these missions are also discussed.

Kaplan, Michael S.↗

Developing technologies for lunar-based astronomy

Prospects for lunar-based astronomy and the development of the required technologies are briefly reviewed. A systematic approach to lunar-based astronomy includes a progression in capability from small automated telescopes to the 16-meter reflector on the moon. A next step beyond the 16-meter reflector will be a Lunar Optical/Ultraviolet/Infrared Synthesis Array. Intermediate steps are represented by the Lunar Transit Telescope and the Lunar Cluster Telescope Experiment. Priorities for the required technology development are identified.

Johnson, Stewart W.↗

A mosaic infrared sensor for space astronomy

The objectives were to give a theoretical and/or experimental evaluation of HgCdTe detector arrays (1 to 5 micron) for space astronomy applications; to analyze low background HgCdTe/CCD coupling schemes for low temperature space astronomy; and to test and evaluate existing silicon CCDs at temperatures below 77 K. The accomplishments are the theoretical tradeoffs for PV-HgCdTe detectors completed at low temperatures; the characterization of existing PV-HgCdTe detector arrays (1 to 5 Micron) at low temperatures (low temperature performance exceeds measurement capability, preamplifier designed and built, and limiting detector current mechanisms analyzed); various detector/CCD coupling approaches were evaluated (resettable gate coupled approach chosen for low background); and low temperature CCD performance at 50 K shows compatibility with astronomical requirements.

Sood, Ashok K.↗

Computation of the Fluid and Optical Fields About the Stratospheric Observatory for Infrared Astronomy (SOFIA) and the Coupling of Fluids, Dynamics, and Control Laws on Parallel Computers

The June 1992 to May 1993 grant NCC-2-677 provided for the continued demonstration of Computational Fluid Dynamics (CFD) as applied to the Stratospheric Observatory for Infrared Astronomy (SOFIA). While earlier grant years allowed validation of CFD through comparison against experiments, this year a new design proposal was evaluated. The new configuration would place the cavity aft of the wing, as opposed to the earlier baseline which was located immediately aft of the cockpit. This aft cavity placement allows for simplified structural and aircraft modification requirements, thus lowering the program cost of this national astronomy resource. Three appendices concerning this subject are presented.

Atwood, Christopher A.↗

Generic mission planning concepts for space astronomy missions

The past two decades have seen the rapid development of space astronomy, both manned and unmanned, and the concurrent proliferation of the operational concepts and software that have been produced to support each individual project. Having been involved in four of these missions since the '70's and three yet to fly in the present decade, the authors believe it is time to step back and evaluate this body of experience from a macro-systems point of view to determine the potential for generic mission planning concepts that could be applied to future missions. This paper presents an organized evaluation of astronomy mission planning functions, functional flows, iteration cycles, replanning activities, and the requirements that drive individual concepts to specific solutions. The conclusions drawn from this exercise are then used to propose a generic concept that could support multiple missions.

Guffin, O. T.↗

Lunar LIGO and gravitational wave astronomy on the Moon

Gravitational wave astronomy continues to be one of the exploration concepts under consideration in NASA's strategy for conducting physics and astrophysics from the lunar surface. As with other proposals for new concepts in science and astronomy from the Moon, this one has a number of very interesting features which need to be developed further in order to assess them adequately. The possibility of robotic deployment of a gravitational wave antenna on the Moon in a triangular configuration and the question of closure on the third interferometer leg are discussed here.

Wilson, Thomas L.↗

NASA's initiative to develop education through astronomy (IDEA)

We describe a progressive program in science education called the Initiative to Develop Education through Astronomy (IDEA). IDEA represents a commitment by the Astrophysics Division of NASA Headquarters to pre-collegiate and public learning. The program enlists the full participation of research astronomers in taking advantage of the natural appeal of astronomy and the unique features of space astrophysics missions to generate valuable learning experiences and scientifically accurate and educationally effective products for students, teachers and citizens. One of the premier projects is called Flight Opportunities for Science Teacher EnRichment (FOSTER) - a program to fly teachers aboard the Kuiper Airborne Observatory during actual research missions. IDEA is managed by a visiting scientist with extensive educational background (each of the authors have served in this role), and the program is unique within NASA science divisions for having a full time scientist devoted to education. IDEA recognizes that the rapidly shifting social and political landscape has caused a fundamental change in how science is expected to contribute to society. It is in the enlightened self-interest of all research scientists to respond to the challenge of connecting forefront research to basic educational needs. IDEA is exploring the avenues needed to facilitate these connections, including supplementing research grants for educational purposes.

Bennett, Jeffrey O.↗

Infrared Astronomy with Arrays: The Next Generation; Sunset Village, Los Angeles, CA, Oct. 1993

Conference papers on infrared array techniques and methods for infrared astronomy are presented. Topics covered include the following: infrared telescopes; infrared spectrometers; spaceborne astronomy; astronomical observatories; infrared cameras; imaging techniques; sky surveys; infrared photography; infrared photometry; infrared spectroscopy; equipment specifications; data processing and analysis; control systems; cryogenic equipment; adaptive optics; image resolution; infrared detector materials; and focal plane arrays.

Mclean, Ian S.↗

An infrared astronomer's early vision of airborne astronomy: Paul Merrill 1920

The first published paper by a professional, research astronomer which discussed airborne astronomy from airplanes was by Paul W. Merrill. In it he proposed some of the types of observations which might be made, looking up at astronomical objects in the sky. This paper describes Merrill's paper, his education, training and subsequent career, and a few other aspects of the early history of airborne astronomy.

Osterbrock, Donald E.↗