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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

The influence of land-atmosphere interactions on variability of the North American Monsoon

Our project focused on the influence of land-atmosphere interactions on variability of North American Monsoon System (NAMS) precipitation is summarized in seven published manuscripts (listed below). Three of these manuscripts (Matsui et al. 2003; Matsui et al. 2005; Small and Kurc 2003) were completed solely with support from this NASA project. The remaining four were completed with additional support from NOAA. Our primary results are summarized: 1) Test of Rocky Mountains snowcover-NAMS rainfall hypothesis. Testing radiation and convective precipitation parameterization in MM5. Analysis of soil moisture-radiation feedbacks in semiarid environments from field observations and modeling.

Small, Eric↗
NASA NTRS2014

Lightweight Inflatable Solar Array: Providing a Flexible, Efficient Solution to Space Power Systems for Small Spacecraft

Affordable and convenient access to electrical power is critical to consumers, spacecraft, military and other applications alike. In the aerospace industry, an increased emphasis on small satellite flights and a move toward CubeSat and NanoSat technologies, the need for systems that could package into a small stowage volume while still being able to power robust space missions has become more critical. As a result, the Marshall Space Flight Center's Advanced Concepts Office identified a need for more efficient, affordable, and smaller space power systems to trade in performing design and feasibility studies. The Lightweight Inflatable Solar Array (LISA), a concept designed, prototyped, and tested at the NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama provides an affordable, lightweight, scalable, and easily manufactured approach for power generation in space or on Earth. This flexible technology has many wide-ranging applications from serving small satellites to soldiers in the field. By using very thin, ultraflexible solar arrays adhered to an inflatable structure, a large area (and thus large amount of power) can be folded and packaged into a relatively small volume (shown in artist rendering in Figure 1 below). The proposed presentation will provide an overview of the progress to date on the LISA project as well as a look at its potential, with continued development, to revolutionize small spacecraft and portable terrestrial power systems.

Johnson, Les↗
NASA NTRS2014

Lightweight Inflatable Solar Array: Providing a Flexible, Efficient Solution to Space Power Systems for Small Spacecraft

Affordable and convenient access to electrical power is critical to consumers, spacecraft, military and other applications alike. In the aerospace industry, an increased emphasis on small satellite flights and a move toward CubeSat and NanoSat technologies, the need for systems that could package into a small stowage volume while still being able to power robust space missions has become more critical. As a result, the Marshall Space Flight Center's Advanced Concepts Office identified a need for more efficient, affordable, and smaller space power systems to trade in performing design and feasibility studies. The Lightweight Inflatable Solar Array (LISA), a concept designed, prototyped, and tested at the NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama provides an affordable, lightweight, scalable, and easily manufactured approach for power generation in space or on Earth. This flexible technology has many wide-ranging applications from serving small satellites to soldiers in the field. By using very thin, ultraflexible solar arrays adhered to an inflatable structure, a large area (and thus large amount of power) can be folded and packaged into a relatively small volume (shown in artist rendering in Figure 1 below). The proposed presentation will provide an overview of the progress to date on the LISA project as well as a look at its potential, with continued development, to revolutionize small spacecraft and portable terrestrial power systems.

Johnson, Len↗
NASA NTRS1972

Optical alignment of electrodes on electrical discharge machines

Shadowgraph system projects magnified image on screen so that alignment of small electrodes mounted on electrical discharge machines can be corrected and verified. Technique may be adapted to other machine tool equipment where physical contact cannot be made during inspection and access to tool limits conventional runout checking procedures.

Boissevain, A. G.↗
NASA NTRS1982

Registration and rectification needs of geology

Geologic applications of remotely sensed imaging encompass five areas of interest. The five areas include: (1) enhancement and analysis of individual images; (2) work with small area mosaics of imagery which have been map projection rectified to individual quadrangles; (3) development of large area mosaics of multiple images for several counties or states; (4) registration of multitemporal images; and (5) data integration from several sensors and map sources. Examples for each of these types of applications are summarized.

Chavez, P. S., Jr.↗
NASA NTRS1987

Three beam-combining schemes in a color projection display

Several beam-combining schemes for on-axis and off-axis optical system layout are presented. The on-axis approaches include two crossed plates with dichroic coatings placed at 90 deg, with respect to each other, and a pentaprism arrangement. The off-axis layout of the cathode ray tubes requires that the images be combined at the display screen. These image-combining approaches are compared for the standard television rates of 525 lines and the high-resolution television at 1200/2000 lines under development in Japan. It is concluded that, for the high-performance, high-color fidelity, and high-resolution projection systems, which are expected to fit into a small volume of space such as a Space Station display or a cockpit panoramic display, a folded configuration with either crossed plates or pentaprism plates will result in an optimum color display.

Scholl, Marija S.↗
NASA NTRS1993

Infrared luminosity functions for the young stellar population associated with the L1641 molecular cloud

Results are reported of a deep near-IR imaging survey which samples 0.77 sq deg of the L1641 star-forming complex and reaches 5 sigma limits at J (1.25 micron,), H (1.65 micron), and K (2.2 microns) of 16.8, 15.8, and 14.7 mag, respectively. A population of about 1500 stars spread throughout the cloud, seven small aggregates comprised of 10-50 stars whose typical projected surface densities exceed that of the distributed population by factors of 4-10, and a heretofore unknown, partially embedded dense cluster comprised of about 150 stars are identified. Analysis of the distribution of (J-H), (H-K), and (R-I) colors for these groups suggest that, in all cases, the stellar populations are dominated by solar-type PMS stars which appear to contain a mix of objects analogous to weak-line T Tauri stars. The present observed luminosity functions are based on reddening-corrected J-band magnitude.

Strom, Karen M.↗
NASA NTRS1999

Effectiveness of Loan Guarantees versus Tax Incentives for Space Launch Ventures

Over the course of the past few years, several new and innovative fully or partiailly reusable launch vehicle designs have been initiated with the objective of reducing the cost of space transportation. These new designs are in various stages hardware development for technology and system demonstrators. The larger vehicles include the Lockheed Martin X-33 technology demonstrator for VentureStar and the Space Access launcher. The smaller launcher ventures include Kelly Space and Technology and Rotary Rocket Company. A common denominator between the new large and small commercial launch systems is the ability to obtain project financing and at an affordable cost. Both are having or will have great difficulty in obtaining financing in the capital markets because of the dollar amounts and the risk involved. The large established companies are pursuing multi-billion dollar developments which are a major challenge to finance because of the size and risk of the projects. The smaller start-up companies require less capital for their smaller systems, however, their lack of corporate financial muscle and launch vehicle track record results in a major challenge to obtain financing also because of high risk. On Wall Street, new launch system financing is a question of market, technical, organizational, legal/regulatory and financial risk. The current limit of acceptable financial risk for Space businesses on Wall Street are the telecommunications and broadcast satellite projects, of which many in number are projected for the future. Tbc recent problems with Iridium market and financial performance are casting a long shadow over new satellite project financing, making it increasingly difficult for the new satellite projects to obtain needed financing.

Scottoline, S.↗
NASA NTRS2004

Curvature-Based Wavefront Sensor for Use on Extended, Arbitrary, Low-Contract Scenes Final Technical Report August 2004

A small amount of work has been done on this project; the strategy to be adopted has been better defined, though no experimental work has been started. 1) Wavefront error signals: The best choice appears use a lenslet array at a pupil image to produce defocused image pairs for each subaperture. Then use the method proposed by Molodij et al. to produce subaperture curvature signals. Basically, this method samples a moderate number of locations in the image where the value of the image Laplacian is high, then taking the curvature signal from the difference of the Laplacians of the extrafocal images at those locations. The tip-tilt error is obtained from the temporal dependence of the first spatial derivatives of an in-focus image, at selected locations where these derivatives are significant. The wavefront tilt can be obtained from the full-aperture image. 2) Extrafocal image generation: The important aspect here is to generate symmetrically defocused images, with dynamically adjustable defocus. The adjustment is needed because larger defocus is required before the feedback loop is closed, and at times when the seeing is worse. It may be that the usual membrane mirror is the best choice, though other options should be explored. 3) Detector: Since the proposed sensor is to work on solar granulation, rather than a point source, an array detector for each subaperture is required. A fast CMOS camera such as that developed by the National Solar Observatory would be a satisfactory choice. 4) Processing: Processing requirements have not been defined in detail, though significantly fewer operations per cycle are required than for a correlation tracker.

LaBonte, Barry J.↗
NASA NTRS2004

Intelligent Control for the BEES Flyer

This paper describes the effort to provide a preliminary capability analysis and a neural network based adaptive flight control system for the JPL-led BEES aircraft project. The BEES flyer was envisioned to be a small, autonomous platform with sensing and control systems mimicking those of biological systems for the purpose of scientific exploration on the surface of Mars. The platform is physically tightly constrained by the necessity of efficient packing within rockets for the trip to Mars. Given the physical constraints, the system is not an ideal configuration for aerodynamics or stability and control. The objectives of this effort are to evaluate the aerodynamics characteristics of the existing design, to make recommendaaons as to potential improvements and to provide a control system that stabilizes the existing aircraft for nominal flight and damaged conditions. Towards this several questions are raised and analyses are presented to arrive at answers to some of the questions raised. CART3D, a high-fidelity inviscid analysis package for conceptual and preliminary aerodynamic design, was used to compute a parametric set of solutions over the expected flight domain. Stability and control derivatives were extracted from the database and integrated with the neural flight control system. The Integrated Vehicle Modeling Environment (IVME) was also used for estimating aircraft geometric, inertial, and aerodynamic characteristics. A generic neural flight control system is used to provide adaptive control without the requirement for extensive gain scheduling or explicit system identification. The neural flight control system uses reference models to specify desired handling qualities in the roll, pitch, and yaw axes, and incorporates both pre-trained and on-line learning neural networks in the inverse model portion of the controller. Results are presented for the BEES aircraft in the subsonic regime for terrestrial and Martian environments.

Krishnakumar, K.↗
NASA NTRS1997

Software Architecture for Autonomous Spacecraft

The thesis objective is to design an autonomous spacecraft architecture to perform both deliberative and reactive behaviors. The Autonomous Small Planet In-Situ Reaction to Events (ASPIRE) project uses the architecture to integrate several autonomous technologies for a comet orbiter mission.

Software Spacecraft ASPIRE project↗
NASA NTRS2006

Reducing Centroid Error Through Model-Based Noise Reduction

A method of processing the digitized output of a charge-coupled device (CCD) image detector has been devised to enable reduction of the error in computed centroid of the image of a point source of light. The method involves model-based estimation of, and correction for, the contributions of bias and noise to the image data. The method could be used to advantage in any of a variety of applications in which there are requirements for measuring precise locations of, and/or precisely aiming optical instruments toward, point light sources. In the present method, prior to normal operations of the CCD, one measures the point-spread function (PSF) of the telescope or other optical system used to project images on the CCD. The PSF is used to construct a database of spot models representing the nominal CCD pixel outputs for a point light source projected onto the CCD at various positions incremented by small fractions of a pixel.

Lee, Shinhak↗
NASA NTRS2015

Electronegative Gas Thruster

The project is an international collaboration and academic partnership to mature an innovative electric propulsion thruster concept to Technology Research Level-3 (TRL-3) through direct thrust measurement. The project includes application assessment of the technology ranging from small spacecraft to high power. The Plasma propulsion with Electronegative GASES(PEGASES) basic proof of concept has been matured to TRL-2 by Ane Aanesland of Laboratoire de Physique des Plasma at Ecole Polytechnique. The concept has advantages through eliminating the neutralizer requirement and should yield longer life and lower cost over conventional gridded ion engines. The objective of this research is to validate the proof of concept through the first direct thrust measurements and mature the concept to TRL-3.

Dankanich, John↗
NASA NTRS2019

A Research Platform for Urban Air Mobility (UAM) and UAS Traffic Management (UTM) Concepts and Application

The purpose of this paper is to describe a research platform for the Urban Air Mobility (UAM) concept. UAM was conceived to enable short-range, low-altitiude service to commuters in metropolitan areas. At the NASA Ames Airspace Operations Laboratory (AOL) user interfaces have been developed to support small UAS operations for the UAS Traffic Management (UTM) project. Due to operational similarities between UAM and UTM, the UTM architecture offers a convenient starting point for research and development of UAM operations. Herein, we begin with an overview of the primary need and expectations characterizing concepts for modern air transportation systems, followed by a brief description of the UTM and UAM concepts. We then describe the UTM architecture, as well as the AOL's research platform and capabilities. The potential applications for UAM research and development are then discussed, providing some direction for future research efforts.

UAM↗
NASA NTRSDate not supplied

In-situ Testing to Acquire HR-EBSD and DIC Strain Data Within a Coincident Domain

For this project, an inked rubber stamp was applied to a small Inconel 625 specimen. The stamp transferred a thin pattern with microscale features for digital image correlation (DIC). The pattern is easily visible at lower voltages and thin enough to not obstruct backscattered electrons. The unique characteristics of the pattern enabled the concurrent acquisition of DIC and high-resolution electron backscatter diffraction (HR-EBSD) data while the specimen was loaded in-situ. The challenges of in-situ testing and combining EBSD with DIC measurements are discussed. By combining the elastic strains (from HR-EBSD) and total strains (from DIC) the result of this approach is an estimate of stress- strain behavior at points across the specimen surface. This combined dataset can then be used as higher-fidelity data in the calibration of crystal plasticity models.

Will Gilliland↗
NASA NTRS1991

NASA SBIR abstracts of 1990 phase 1 projects

The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number.

Schwenk, F. C.↗
NASA NTRS1976

Reconstructing color images of astronomical objects using black and white spectroscopic emulsions

A color photograph of the peculiar elliptical galaxy NGC 5128 (Centaurus A) has been reconstructed from three Kodak 103a emulsion type photographs by projecting positives of the three B&W plates through appropriate filters onto a conventional color film. The resulting photograph shows color balance and latitude characteristics superior to color photographs of similar astronomical objects made with commercially available conventional color film. Similar results have been obtained for color reconstructed photographs of the Large and Small Magellanic Clouds. These and other results suggest that these projection-reconstruction techniques can be used to obtain high-quality color photographs of astronomical objects which overcome many of the problems associated with the use of conventional color film for the long exposures required in astronomy.

Dufour, R. I.↗