SEARCH · Search NASA

Results for “inexpensive”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36

All sources NASA NTRS DOE OSTI

NASA NTRS1984

GaAs CLEFT solar cells for space applications

Although GaAs solar cells are radiation-resistant and have high conversion efficiencies, there are two major obstacles that such cells must overcome before they can be widely adopted for space applications: GaAs wafers are too expensive and cells made from these wafers are too heavy. The CLEFT process permits the growth of thin single-crystal films on reusable substrates, resulting in a drastic reduction in both cell cost and cell weight. Recent advances in CLEFT technology have made it possible to achieve efficiencies of about 14 percent AM0 for 0.51-sq cm GaAs solar cells 5 microns thick with a 41-mil-thick coverglass. In preliminary experiments efficiencies close to 19 percent AM1 have been obtained for 10-micron-thick cells. It is suggested that the CLEFT technology should yield inexpensive, highly efficient modules with a beginning-of-life specific power close to 1 kW/kg (for a coverglass thickness of 4 mils).

Fan, J. C. C.↗

NASA NTRS1985

A swirl flow evaporative cold plate

A forced flow evaporative cold plate is under development for future application to the thermal bus concept being pursued by NASA for Space Station Thermal Control. The vaporizer is a swirl-flow device employing a spiral tube coil geometry sandwiched between conductive metal plates upon which electric components could be mounted. This concept is based on the inherent phase separation that occurs in a two phase stream in curvilinear flow. This is a zero 'g' design with one 'g' all-attitude capability and is capable of high heat transfer coefficients, good isothermality, and the ability to function at heat fluxes approaching 5w/sq cm on the cold plates (10w/sq cm on the tube wall) with Freon 114. The advantages of this design over other two phase evaporator approaches are high heat flux capability, simplified control requirements, insensitivity to micro-gravity oscillations, and inexpensive manufacturability. The program included design, fabrication, and test of such a cold plate utilizing an existing test stand developed for two-phase thermal management system (TPTMS) testing. Test results analysis and conclusions are included.

Niggemann, R. E.↗

NASA NTRS1985

Recent materials problems relating to catastrophic balloon failures

Balloons fabricated of thin polyethylene materials have provided relatively inexpensive and reliable scientific research platforms for approximately three decades. Reliability of the modern day balloon, as launched by the U.S.A. National Scientific Balloon Facility (NSBF), has been approximately 85 percent. Recent balloon failures, coupled with an increased ocurrence of catastrophic failures, created grave concern over the integrity of the present balloon inventory of the U.S.A. National Aeronautics and Space Administration (NASA). An investigative team was established by NASA to review the circumstances surrounding the catastrophic balloon failures, determine the cause and to make recommendations to correct the problem and to prevent its reoccurrence. The most probable cause of failure as determined by the investigation was the polyethylene balloon film, although the film had passsed the established standard quality control measures of the film manufacturer. The approach, findings, and conclusions of the investigation are presented along with planned procedures to assure future quality balloon film for NASA balloons.

Smith, I. S.↗

NASA NTRS1984

Medical ultrasound - From inner space to outer space

During the last decade, medical ultrasound has rapidly become a widely accepted imaging modality used in many medical specialties. It has the advantages that it is noninvasive, does not use ionizing radiation, is relatively inexpensive and is easy to use. Future trends in ultrasound include expanded areas of use, advanced signal processing and digital image analysis including tissue characterization and three-dimensional reconstructions.

Rooney, J. A.↗

NASA NTRS1985

Space Shuttle ice prevention studies

Turbojet engine exhausts are being considered for the prevention of ice formation on the Space Shuttle External Tank (ET) when cryogenic propellants are loaded. The ice could dislodge and damage the Thermal Protection System tiles of the Shuttle Orbiter. An oil flow visualization technique was developed to quickly and inexpensively study the flowfields created by jet exhausts. The procedure can also determine the influence of geometry, jet exhausts, and wind conditions on the size and location of flow regions. A black tempra and kerosene mixture was applied to an ET model; the wind tunnel and jet flow were started; and when they stopped the flow patterns were photographed to determine which parameters had the greatest influence on the flowfields.

Porteiro, J. L. F.↗

NASA NTRS1986

Video Processor for Transponder Pulses

Circuit detects interrogation signals from air-traffic-control station and determines whether transponder of airplane should respond. Circuit examines relative magnitudes of first two pulses in three-pulse sequence of interrogation signal. On basis of relative magnitudes, circuit decides whether main lobe of interrogating radar beam is received (response should be generated) or only side lobe received (and interrogation ignored). Circuit simple and inexpensive.

Byrne, F.↗

NASA NTRS1986

Temperature-Sensitive Oscillator

Ingestible thermometer consists of oscillator with temperature-dependent frequency. Device is quartz-crystal oscillator, frequency of which changes in proportion to change in temperature. Temperature-Sensitive Oscillator with nearly linear temperature coefficient of frequency obtained by using high-speed, high-gain, programable operational amplifier such as OP-32 to produce temperature-varying reflected capacitance across quartz crystal. New, small, inexpensive, low-power, temperature-sension circuit suitable for use as ingestible thermometer for measuring internal body temperature.

Kleinberg, L. L.↗

NASA NTRS1986

Analog Video Image-Enhancing Device

Inexpensive system yields pseudo-three-dimensional effect. Includes video camera with lens, connected to video monitor for analog video enhancement. Video signal obtained from monitor at point beyond where synchronization signals are detected, eliminating need to regenerate composite video signal. Analog video image-enhancing device improves appearance of technical photographs by selectively compressing overall dynamic ranges while accentuating edges or small details of greatest interest.

Weinstein, L. M.↗

NASA NTRS1986

Phase-Measuring System

System developed and used at Langley Research Center measures phase between two signals of same frequency or between two signals, one of which is harmonic multiple of other. Simple and inexpensive device combines digital and analog components to give accurate phase measurements. One signal at frequency f fed to pulse shaper, produces negative pulse at time t4. Pulse applied to control input of sample-and-hold module 1. Second signal, at frequency nf, fed to zero-crossover amplifier, producing square wave at time t. Signal drives first one-shot producing narrow negative pulse at t1. Signal then drives second one-shot producing narrow positive pulse at time t2. This pulse used to turn on solid-state switch and reset integrator circuit to zero.

Davis, W. T.↗

NASA NTRS1986

Cleaning High-Voltage Equipment With Corncob Grit

High electrical resistance of particles makes power shutdown unnecessary. New, inexpensive method of cleaning high-voltage electrical equipment uses plentiful agricultural product - corncob grit. Method removes dirt and debris from transformers, circuit breakers, and similar equipment. Suitable for utilities, large utility customers, and electrical-maintenance services.

Caveness, C.↗

NASA NTRS1986

Function-Keypad Template Filer

Each page of filer shows various keypad designations corresponding to variety of software packages. Filer has various templates bound together so they are indexed easily and stand up for ready viewing. Template filers are made of inexpensive materials. Templates of various manufacturers can be added in pages appropriately die cut to receive them. Microcomputer operators using variety of software packages assisted by simple filer that illustrates various keyboard functions corresponding to different software packages. Keyboard functions change, depending on selected software. Filer has set of templates showing keyboard functions for various software packages. Templates set up quickly as desktop references to key functions.

Headley, P. A.↗

NASA NTRS1986

Economic Comparison of Processes Using Spreadsheet Programs

Inexpensive approach aids plant-design decisions. Commercially available electronic spreadsheet programs aid economic comparison of different processes for producing particular end products. Facilitates plantdesign decisions without requiring large expenditures for powerful mainframe computers.

Ferrall, J. F.↗

NASA NTRS1986

Flexible Diaphragm Withstands Extreme Temperatures

Diaphragm seal retains flexibility throughout temperature range of -200 to +600 degree F (-129 to +316 degree C). Diaphragm durable, simple, versatile, and relatively inexpensive to manufacture. Suitable for refrigeration seals, autoclaves, storage lockers, and other sealing applications subjected to extreme temperature differentials.

Lerma, G.↗

NASA NTRS1986

Covering Cavities by Electrodeposition

Reworking technique allows complex surfaces to be reshaped. Contours of large machined parts reworked quickly and inexpensively by electrodeposition and machining, with little risk of damage. Reworking method employs simple, reliable, well-known procedures.

Schmeets, M.↗

NASA NTRS1985

Research on solar pumped liquid lasers

A solar pumped liquid laser that can be scaled up to high power (10 mW CW) for space applications was developed. Liquid lasers have the advantage over gases in that they provide much higher lasant densities and thus high-power densities. Liquids also have advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13: Nd sup 3+:ZrC14 liquid was chosen for its high intrinsic efficiency and its relatively good stability against decomposition due to protic contamination. The development of a manufacturing procedure and performance testing of the laser, liquid and the development of an inexpensive large solar concentrator to pump the laser are examined.

Cox, J. D.↗

NASA NTRS1985

Experiments with solid particle seeding

Kaoline, a hydrated aluminum silicate clay, is investigated as a seeding material for laser velocimetry. It is inexpensive but is polydispersed with some of the fineparticles being too large to follow wind tunnel flow and is in the form of nonspherical platelets having an aspect ratio of approximately 4/1. Gravity sedimentation experiments as a means of narrowing the fineparticle sizes distribution are being conducted. The fineparticle size distribution of Engelhard ASP 200 kaolin suspended in ethanol (0.00792 grams kaolin/ml ethanol) as received, after 24 hours gravity sedimentation and after 48 hours sedimentation, respectively is shown. A shearing atomizer is used to inject the fineparticles. Gravity sedimentation is carried out in an 800 ml pyrex beaker. Following gravity sedimentation, the top 3.5 inches are siphoned from the liquid, which has a column height of 4.5 inches. In a like manner, longer settling times will serve to further narrow the fineparticle distribution range. As successive sedimentations are effected, the number of fineparticles per unit volume of ethanol decreased markedly.

Nichols, C. E., Jr.↗

NASA NTRS1985

A report on the ST ScI optical disk workstation

The STScI optical disk project was designed to explore the options, opportunities and problems presented by the optical disk technology, and to see if optical disks are a viable, and inexpensive, means of storing the large amount of data which are found in astronomical digital imagery. A separate workstation was purchased on which the development can be done and serves as an astronomical image processing computer, incorporating the optical disks into the solution of standard image processing tasks. It is indicated that small workstations can be powerful tools for image processing, and that astronomical image processing may be more conveniently and cost-effectively performed on microcomputers than on the mainframe and super-minicomputers. The optical disks provide unique capabilities in data storage.

Source record↗

NASA NTRS1985

Spartan service module finite element modeling technique and analysis

Sounding rockets have served as a relatively inexpensive and easy method of carrying experiments into the upper atmosphere. Limited observation time and pointing capabilities suggested the development of a new sounding rocket type carrier compatible with NASA's Space Transportation System. This concept evolved into the Spartan program, now credited with a successful Spartan 101 mission launched in June 1985. The next series of Spartans will use a service module primary structure. This newly designed reusable and universal component in the Spartan carrier system required thorough analysis and evaluation for flight certification. Using advanced finite element modeling techniques, the structure was analyzed and determined acceptable by meeting strict design goals and will be tested for verification of the analytical results.

Lindenmoyer, A. J.↗