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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Optical infrared sky survey

A description is presented of a photographic survey of the northern sky currently underway at Steward Observatory. The survey is being conducted at a principal bandpass of 8000-9000 A supplemented by a V bandpass. The survey is the first of its type conducted using a small (20-in. aperture) wide-field telescope, a very large-format (146 mm) image intensifier with a red-extended, multialkali photocathode. The output phosphor of the intensifier is photographed with IIaD emulsion on film. One of the goals of the survey is to catalog red stellar objects on the photographs and to examine in detail regions of the sky which are obscured by hydrogen emission on conventional photographs.

Craine, E. R.↗
NASA NTRS1982

Infrared, optical, and ultraviolet observations of hydrogen line emission from Seyfert galaxies

Nearly simultaneous observations are reported of P-alpha, H-alpha, and H-beta emission from 18 Seyfert galaxies and of Ly-alpha from eight of these galaxies. In many cases, P-alpha is stronger relative to the Balmer lines than is predicted by recombination calculations; reddening appears to be required. Dispersion in the P-alpha/H-alpha/H-beta ratios orthogonal to the reddening track indicates that high densities or optical depths also affect the line flux ratios. Several galaxies, notably NGC 1275, have very low P-alpha/H-alpha ratios. High densities, large optical depths, and reddening probably all contribute to the low observed Ly-alpha/H-beta ratios.

Lacy, J. H.↗
NASA NTRS1986

Ultraviolet, optical, infrared, and microwave observations of HR 5110

Near-IR JHKLM photometric data and VLBI and IUE radio burst data collected on the short-period spectroscopic binary HR 5110 are analyzed to classify the object. The observed broadband colors were indicative of an F2 IV primary and a spotted K0 IV secondary. The system is being viewed pole-on, so is observable in the UV since the K companion has filled its Roche lobe. In comparisons of such features of Algol and RS VCn stars as the mass ratio, orbital inclination, presence or absence of evidence for mass streams, accretion disks, and active regions, spectral signatures, etc., sufficient similarities are found to classify HR 5110 as an Algol system.

Little-Marenin, I. R.↗
NASA NTRS1987

Optical and infrared space optics challenges

A number of optical design and technology challenges are discussed with reference to specific space optics projects. The projects examined include the Large Deployable Reflector, multiple-mirror telescopes, the Hubble Space Telescope, and the Circumstellar Imaging Telescope. Other projects discussed include a voyage to a distance of 1000 astronomical units, the Shuttle Imaging Spectrometer Experiment, and directional optical systems. The ultimate challenge is the detection of and communication with any planets that may be discovered around nearby stars.

Meinel, Aden B.↗
NASA NTRS1988

Surface temperature determination in surface analytic systems by infrared optical pyrometry

An IR pyrometric technique for measuring the surface temperatures of metal specimens in an ultrahigh-vacuum analytic chamber is described and demonstrated. The experimental setup comprises a commercial IR microscope with a long-working-distance right-angle objective (focal spot diameter 1 mm at 53 cm), a metal-coated glass vacuum chamber with a Ta-mesh-covered quartz viewport, an Mo specimen stub with an internal heating element, and a Ta disk test specimen with a flat side coated with a high-emissivity graphite film. The results of an initial calibration test are presented graphically and briefly characterized. The measurement error at 450 C is found to be less than 10 C.

Wheeler, Donald R.↗
NASA NTRS1991

The joint far-infrared-optical luminosity function for spiral galaxies and data for the Abell 400 and Cancer clusters

Visual and IRAS data for an optically selected sample of 183 late-type galaxies are compiled in tables and graphs and analyzed in detail to determine the joint FIR-optical luminosity function Psi from the FIR/blue luminosity ratio, r = L(FIR)/L(B). It is found that Psi can be approximated by a function of a single variable psi(r-prime), where r-prime is defined as r times L(B)/L(asterisk) exp -delta, with L(asterisk) a constant and delta = about 0.08. A lognormal curve peaking at r-prime = 0.35 and with dispersion of 0.28 is shown to give a good fit to psi(r-prime). From a lack of galaxies with very low r-prime in the present sample it is inferred that there are few spiral galaxies with low interstellar-dust abundances. Also included are data on the distribution function of r-prime for the more distant clusters Abell 400 and Cancer.

Corbelli, Edvige↗
NASA NTRS1991

High quality flame deposited diamond films for infrared optical windows

The IR absorption in polycrystalline diamond films deposited in oxygen-acetylene flames is characterized using FTIR. The one-phonon absorption coefficient in the region from 7 to 12 microns that is related to extrinsic defects in the diamond films shows a strong dependence on the flame conditions as well as the substrate temperature. A high degree of diamond crystalline perfection, as judged from the undetectable one-phonon absorption, is achieved under the optimized deposition conditions for our flame setup. This is further supported by the sharp Raman peak at 1332/cm as well as the high purity in crystal orientation according to the X-ray diffraction pattern measured for the high quality diamond films.

Tzeng, Y.↗
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 NTRS2004

Nanotechnology Infrared Optics for Astronomy Missions

We have used the "MicroStripes" code (Flomerics, Inc.) to perform full-, near- and far-field diffraction modeling of metal mesh performance on substrates. Our Miles Code software, which approximates the full calculation in a quick, gui-based window, is useful as an iterative device by adjusting the input parameters (index of refraction, thickness, etc.) to provide agreement with the full calculation. However, despite the somewhat extravagant claims by the MicroStripes manufacturer, this code is also not perfect because numerous free parameters must be set. Key among these, as identified in our earlier papers and proposal documents, is the high frequency (i.e., far IR) character of the real and imaginary parts of the index of refraction of the metal mesh, the high frequency character of the real and imaginary parts of the index of refraction of the substrate, and the character of the interface between the mesh and the substrate material, and in particular the suppression (or possible enhancement) of surface effects at the interface.

Frogel, Jay↗
NASA NTRS1996

Infrared Optical Properties of La(sub 0.7)Ca(sub 0.3)MnO(sub 3) Epitaxial Films

The reflectance of La(sub 0.7)Ca(sub 0.3)MnO(sub 3) epitaxial films on perovskite substrates with a range of lattice constants is studied in the frequency range of 50 cm(sup -1) - 5000cm(sup -1). The complex dielectric functions of the bare La(sub 0.7)Ca(sub 0.3)MnO(sub 3) films are obtained by modeling the measured reflectivity spectra of the two-layer La(sub 0.7)Ca(sub 0.3)MnO(sub 3)/substrate system with separaately measured dielectric functions of the bare substrate.

lattice distortion epitaxial films lattice polaron↗
NASA NTRS2015

Technology Development for the Advanced Technology Large Aperture Space Telescope (ATLAST) as a Candidate Large UV-Optical-Infrared (LUVOIR) Surveyor

The Advanced Technology Large Aperture Space Telescope (ATLAST) team has identified five key technologies to enable candidate architectures for the future large-aperture ultraviolet/optical/infrared (LUVOIR) space observatory envisioned by the NASA Astrophysics 30-year roadmap, Enduring Quests, Daring Visions. The science goals of ATLAST address a broad range of astrophysical questions from early galaxy and star formation to the processes that contributed to the formation of life on Earth, combining general astrophysics with direct-imaging and spectroscopy of habitable exoplanets. The key technologies are: internal coronagraphs, starshades (or external occulters), ultra-stable large-aperture telescopes, detectors, and mirror coatings. Selected technology performance goals include: 1x1010 raw contrast at an inner working angle of 35 milli-arcseconds, wavefront error stability on the order of 10 pm RMS per wavefront control step, autonomous on-board sensing & control, and zero-read-noise single-photon detectors spanning the exoplanet science bandpass between 400 nm and 1.8 μm. Development of these technologies will provide significant advances over current and planned observatories in terms of sensitivity, angular resolution, stability, and high-contrast imaging. The science goals of ATLAST are presented and flowed down to top-level telescope and instrument performance requirements in the context of a reference architecture: a 10-meter-class, segmented aperture telescope operating at room temperature (~290 K) at the sun-Earth Lagrange-2 point. For each technology area, we define best estimates of required capabilities, current state-of-the-art performance, and current Technology Readiness Level (TRL) - thus identifying the current technology gap. We report on current, planned, or recommended efforts to develop each technology to TRL 5.

Technology Development↗
NASA NTRS2016

Initial Technology Assessment for the Large-Aperture UV-Optical-Infrared (LUVOIR) Mission Concept Study

The NASA Astrophysics Division's 30-Year Roadmap prioritized a future large-aperture space telescope operating in the ultra-violet/optical/infrared wavelength regime. The Association of Universities for Research in Astronomy envisioned a similar observatory, the High Definition Space Telescope. And a multi-institution group also studied the Advanced Technology Large Aperture Space Telescope. In all three cases, a broad science case is outlined, combining general astrophysics with the search for biosignatures via direct-imaging and spectroscopic characterization of habitable exoplanets. We present an initial technology assessment that enables such an observatory that is currently being studied for the 2020 Decadal Survey by the Large UV/Optical/Infrared (LUVOIR) surveyor Science and Technology Definition Team. We present here the technology prioritization for the 2016 technology cycle and define the required technology capabilities and current state-of-the-art performance. Current, planned, and recommended technology development efforts are also reported.

technology development↗
NASA NTRS2022

Characterization of Infrared Optical Motion Tracking System in NASA's Simulated Lunar Operations (SLOPE) Laboratory

This work characterizes the accuracy of a 16 camera OptiTrack motion tracking system installed in NASA Glenn Research Center's Simulated Lunar Operations (SLOPE) laboratory. The position of a rigid body mounted on a motorized linear stage is compared to its position reported by the motion tracking system as it travels through the facility's 777m$^3$ capture volume of interest. Experiments show that the mean error reported by the motion tracking system for the aggregate capture volume is in-line with independent measurements collected using the motion stage. Error within regions of the capture volume exceed the mean error reported by the motion tracking system, likely due to occlusion, and suggests that additional cameras should be used to increase measurement accuracy in these regions. Overall, results show that error values reported by the motion tracking system are representative of the measurement error in a collected data set and validates the system's use for characterizing the mobility and tractive performance of robots, rovers, and other vehicles for planetary exploration.

Motion capture↗