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Results for “optics space astronomy”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Optical space astronomy and goals of the large space telescope.

Optical astronomy now means the study of EM radiation in the very near IR and vacuum UV in addition to the visible wavelengths. Practical constraints presently define the IR limit at about 11000 A, where photoemissive cathodes become ineffective, and the UV limit at 912 A, where the hydrogen of the interstellar medium limits the view to very nearby objects. Salient events of the first decade of optical space astronomy are discussed together with the orbiting astronomical observatories. Particular attention is given to the large space telescope (LST) project, taking into account the physical characteristics of the LST and the scientific program.

O'Dell, C. R.↗
NASA NTRS2001

Ultraviolet-Optical Space Astronomy Beyond HST Conference (Origins Conference and UV-Optical Working Group Support)

This grant supported three major activities, from 1997-2001. (1) Origins Conference. The funds from this grant were used, initially, to support a Conference on "Origins", held May 19-23, 1997 at Estes Park, CO and attended by a wide range of astronomers, planetary scientists, and astrobiologists. The scientific proceedings of this meeting were published in 1998 by the Astronomical Society of the Pacific: "Origins" (1998) "Proceedings of the International Origins Conference". (2) UV-Optical Space Astronomy. Conference Additional funds provided by the NASA Office of Space Science were used to support a meeting held August 5-7, 1998 at Boulder, CO and attended by ultraviolet and optical astronomers and instrumentalists interested in a UV-O successor to the Hubble Space Telescope. The scientific proceedings of this meeting were published in 1999: "Ultraviolet-Optical Space Astronomy Beyond the Hubble Space Telescope" (1999), NASA provided funds and commissioned the UVOWG (Ultraviolet-Optical Working Group), charged with recommending a set of fundamental scientific problems and new space missions in the UV/Optical wavelength bands. The working group was chaired by J. M. Shull, and included ten other astrophysicists. Their report was published as a "White Paper" (Nov. 1999) entitled "The Emergence of the Modern Universe: Tracing the Cosmic Web" available. The results of this report were used in the NASA Strategic Planning ("Roadmap") exercise and by the NRC Astronomy/Astrophysics Decade Committee.

Shull, J. Michael↗
NASA NTRS1972

Active optics for space astronomy.

Discussion of the segmented and deformable active optics approaches underlying some of the modern electrooptical techniques that are to be used in the design of future generations of giant-aperture orbital space telescopes. Combinations of laser interferometry and precise servomechanisms are shown to make possible the solution of such key problems of large monolithic mirrors in orbit as weight, thermal distortion, launchability, and material stability. The applicability of these active optics approaches to future giant-aperture space astronomy systems in the 200-inch to 400-inch diameter range is reviewed.

Wischnia, H. F.↗
NASA NTRS1996

Exploration an the Search for Origins: A Vision for Ultraviolet-Optical-Infrared Space Astronomy

Public support and enthusiasm for astronomy have been strong in the final decades of the twentieth century. Nowhere is this better demonstrated than with the Hubble Space Telescope (HCT), a grand endeavor, which is enabling astronomers to make giant strides in understanding our universe, our place in it, and our relation to it. The NASAs first infrared observatory, the Space Infrared Telescope Facility (SIRTF), promises to take the crucial next steps towards understanding the formation of stars and galaxies. Toward their completion, the HST and Beyond Committee identifies major goals, whose accomplishment will justify a commitment well into the next century: (1) the detailed study of the birth and evolution of normal galaxies such as the Milky Way; (2) the detection of Earth-like planets around other stars and the search for evidence of life on them; (3) NASA should develop a space observatory of aperture 4m or larger, optimized for imaging and spectroscopy over the wavelength range 1-5 microns; and (4) NASA should develop the capability for space interferometry.

Dressler, Alan↗
NASA NTRS1979

Space optics; Proceedings of the Seminar, Huntsville, Ala., May 22-24, 1979

The seminar focused on infrared systems, the space telescope, new design for space astronomy, future earth resources systems, and planetary systems. Papers were presented on infrared astronomy satellite, infrared telescope on Spacelab 2, design alternatives for the Shuttle Infrared Telescope Facility, Spacelab 2 infrared telescope cryogenic system, geometrical theory of diffraction and telescope stray-light analysis, Space Telescope scientific instruments, faint-object spectrograph for the Space Telescope, light scattering from multilayer optics, bidirectional reflectance distribution function measurements of stray light suppression coatings for the Space Telescope, optical fabrication of a 60-in. mirror, interferogram analysis for space optics, nuclear-pumped lasers for space application, geophysical fluid flow experiment, coherent rays for optical astronomy in space, optical system with fiber-optical elements, and Pioneer-Venus solar flux radiometer.

Wyman, C. L.↗
NASA NTRS2014

Exo-C: a Probe-Scale Space Mission to Directly Image and Spectroscopically Characterize Exoplanetary Systems Using an Internal Coronagraph

"Exo-C" is NASA's first community study of a modest aperture space telescope designed for high contrast observations of exoplanetary systems. The mission will be capable of taking optical spectra of nearby exoplanets in reflected light, discover previously undetected planets, and imaging structure in a large sample of circumstellar disks. It will obtain unique science results on planets down to super-Earth sizes and serve as a technology pathfinder toward an eventual flagship-class mission to find and characterize habitable exoplanets. We present the mission/payload design and highlight steps to reduce mission cost/risk relative to previous mission concepts. At the study conclusion in 2015, NASA will evaluate it for potential development at the end of this decade. Keywords: Exoplanets, high contrast imaging, optical astronomy, space mission concepts

high contrast imaging↗
NASA NTRS2000

Electro-Formed Mirrors for Both X-Ray and Visible Astronomy

The Space Optics Manufacturing Technology Center of NASA's Marshall Space Flight Center is involved in the development of nickel and nickel alloy electroformed mirrors for rapid production of space-based optical systems. The current state of the process is discussed- for both cylindrical x-ray mirrors and normal incidence mirrors for visible and infrared applications.

Ritter, J.↗
NASA NTRS2007

Applied Astronomy: An Optical Survey for Space Debris at GEO

A viewgraph is presented to discuss space debris at Geosynchronous Earth Orbit (GEO). The topics include: 1) Syncom1 launched February 14, 1963 Failed on orbit insertion 1st piece of GEO debris!; 2) Example of recent GEO payload: XM-2 Rock satellite for direct broadcast radio; 3) MODEST Michigan Orbital DEbrisSurvey Telescope the telescope formerly known as the Curtis-Schmidt; 4) GEO Debris Survey; 5) Examples of Detections; 6) Brightness Variations Common; 7) Observed Angular Rates; 8) Two Populations at GEO; 9) High Area-to-Mass Ratio Material (A/M); 10) Examples of MLI; 11) Examples of MLI Release in LEO; 12) Liou & Weaver (2005) models; 13) ESA 1-m Telescope Survey; 14) Two Telescopes March 2007 Survey and Follow-up; 15) Final Eccentricity; and 16) How control Space Debris?

Seitzer, Patrick↗
NASA NTRS2015

Investigating the Efficacy of CubeSats for Asteroid Detection

A simulation to examine the potential of a network of CubeSats for detecting Near Earth Objects is discussed, in terms of goals, methods used and initial results obtained. By designing a basic optical system and the orbital parameters of the satellites in this network, their effectiveness for detecting asteroids is examined, with a small sample of cataloged asteroids considered.The conditions to be satisfied for detection cover both the geometrical aspects of astronomy such as field of view and line of sight, along with more technical optics-based conditions such as resolution and sensitivity of our telescopes. Of special interest to us in this work is the region of the sky between 45 deg. and 90 deg. from the Sun, as seen from the Earth. This part of the sky is currently unobservable by ground-based surveys and so provides the primary reason to consider a space-based one. There exist a number of issues with the simulation which call these results into question, but an eort has been made to remove those results which exceed the possible capabilities of the satellite network, and identify those aspects of the mission which should be examined in order to provide an in-depth assessment of it's performance. With these filters applied to the overall data, a tentative result of 1458 total detections over an 85 year period has been obtained, with 14 of the 22 asteroids in the sample being detected at least once. A number of ways in which the simulation could be improved are also proposed, both in-terms of addressing the aforementioned issues, as well as how to improve on the accuracy of the simulation and capture as many aspects of a space-based optical astronomy mission as possible,with the possible nal form of the simulation being a tool for assessing the performance of any space-based optical mission to detect asteroids.

Near Earth Objects↗
NASA NTRS1992

Report of the Science Working Group: Science with a lunar optical interferometer

Resolution is the greatest constraint in observational astronomy. The Earth's atmosphere causes on optical image to blur to about 1 arcsec or greater. Interferometric techniques have been developed to overcome atmospheric limitations for both filled aperture conventional telescopes and for partially filled aperture telescopes, such as the Michelson or the radio interferometer. The Hubble Space Telescope (HST) represents the first step toward space based optical astronomy. The HST represents an immediate short term evolution of observational optical astronomy. A longer time scale of evolution is focused on and the benefits are considered to astronomy of placing an array of telescopes on the Moon at a time when a permanent base may exist there.

Source record↗
NASA NTRS1997

Construction of Prototype Lightweight Mirrors

This contract and the work described was in support of a Seven Segment Demonstrator (SSD) and demonstration of a different technology for construction of lightweight mirrors. The objectives of the SSD were to demonstrate functionality and performance of a seven segment prototype array of hexagonal mirrors and supporting electromechanical components which address design issues critical to space optics deployed in large space based telescopes for astronomy and for optics used in spaced based optical communications systems. The SSD was intended to demonstrate technologies which can support the following capabilities; Transportation in dense packaging to existing launcher payload envelopes, then deployable on orbit to form space telescope with large aperture. Provide very large (less than 10 meters) primary reflectors of low mass and cost. Demonstrate the capability to form a segmented primary or quaternary mirror into a quasi-continuous surface with individual subapertures phased so that near diffraction limited imaging in the visible wavelength region is achieved. Continuous compensation of optical wavefront due to perturbations caused by imperfections, natural disturbances, and equipment induced vibrations/deflections to provide near diffraction limited imaging performance in the visible wavelength region. Demonstrate the feasibility of fabricating such systems with reduced mass and cost compared to past approaches. While the SSD could not be expected to satisfy all of the above capabilities, the intent was to start identifying and understanding new technologies that might be applicable to these goals.

Robinson, William G.↗
NASA NTRS1997

Adaptive Full Aperture Wavefront Sensor Study

This grant and the work described was in support of a Seven Segment Demonstrator (SSD) and review of wavefront sensing techniques proposed by the Government and Contractors for the Next Generation Space Telescope (NGST) Program. A team developed the SSD concept. For completeness, some of the information included in this report has also been included in the final report of a follow-on contract (H-27657D) entitled "Construction of Prototype Lightweight Mirrors". The original purpose of this GTRI study was to investigate how various wavefront sensing techniques might be most effectively employed with large (greater than 10 meter) aperture space based telescopes used for commercial and scientific purposes. However, due to changes in the scope of the work performed on this grant and in light of the initial studies completed for the NGST program, only a portion of this report addresses wavefront sensing techniques. The wavefront sensing techniques proposed by the Government and Contractors for the NGST were summarized in proposals and briefing materials developed by three study teams including NASA Goddard Space Flight Center, TRW, and Lockheed-Martin. In this report, GTRI reviews these approaches and makes recommendations concerning the approaches. The objectives of the SSD were to demonstrate functionality and performance of a seven segment prototype array of hexagonal mirrors and supporting electromechanical components which address design issues critical to space optics deployed in large space based telescopes for astronomy and for optics used in spaced based optical communications systems. The SSD was intended to demonstrate technologies which can support the following capabilities: Transportation in dense packaging to existing launcher payload envelopes, then deployable on orbit to form a space telescope with large aperture. Provide very large (greater than 10 meters) primary reflectors of low mass and cost. Demonstrate the capability to form a segmented primary or quaternary mirror into a quasi-continuous surface with individual subapertures phased so that near diffraction limited imaging in the visible wavelength region is achieved. Continuous compensation of optical wavefront due to perturbations caused by imperfections, natural disturbances, and equipment induced vibrations/deflections to provide near diffraction limited imaging performance in the visible wavelength region. Demonstrate the feasibility of fabricating such systems with reduced mass and cost compared to past approaches.

Robinson, William G.↗
NASA NTRS1988

Normal incidence reflectance of ion beam deposited SiC films in the EUV

Results are presented from an experimental investigation of the normal-incidence reflectance at 58.4, 92.0, and 121.6 nm wavelength of 30- and 80-nm-thick SiC films produced by ion-beam deposition on unheated 5 x 5-cm microscope slides. The films were deposited in the 2-m evaporator described by Bradford et al. (1969) with chamber base pressure 1 microtorr, operating pressure 40 microtorr, and a 50-62-mA 750-eV Ar ion beam; the reflectance measurements were obtained in the reflector-monochromator system described by Osantowski (1974). Reflectances of over 30 percent were found at 92 and 121.6 nm, almost equal to those of polished CVD films of SiC and degrading only slightly after aging for 4 months. It is suggested that ion-beam deposition may be the best low-temperature technique for coating EUV optics for space astronomy.

Keski-Kuha, Ritva A. M.↗