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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 NTRS1992

Melt flow properties of LARC-TPI 1500 series mixtures

This study examines the melt-flow properties of 50/50 mixtures of high flow grade/medium flow grade LARC-TPI 1500 series pellets and a new form (94/6), of medium flow grade material which contains 6 percent of a low molecular weight imide additive. The flow properties are compared with previously reported flow properties of mixtures of earlier batches of high and medium flow grade TPI 1500 materials. Unlike the earlier batches of materials, the later materials were synthesized and mixed at Mitsui Toatsu Chemicals, Inc., Japan, and made into pellets before NASA received them for characterization. They exhibited a lower melt viscosity as well as improved melt stability.

Burks, H. D.↗
NASA NTRS1992

Analysis of DGPS/INS and MLS/INS final approach navigation errors and control performance data

Flight tests were conducted jointly by NASA Langley Research Center and Honeywell, Inc., on a B-737 research aircraft to record a data base for evaluating the performance of a differential DGPS/inertial navigation system (INS) which used GPS Course/Acquisition code receivers. Estimates from the DGPS/INS and a Microwave Landing System (MLS)/INS, and various aircraft parameter data were recorded in real time aboard the aircraft while flying along the final approach path to landing. This paper presents the mean and standard deviation of the DGPS/INS and MLS/INS navigation position errors computed relative to the laser tracker system and of the difference between the DGPS/INS and MLS/INS velocity estimates. RMS errors are presented for DGPS/INS and MLS/INS guidance errors (localizer and glideslope). The mean navigation position errors and standard deviation of the x position coordinate of the DGPS/INS and MLS/INS systems were found to be of similar magnitude while the standard deviation of the y and z position coordinate errors were significantly larger for DGPS/INS compared to MLS/INS.

Hueschen, Richard M.↗
NASA NTRS1993

Application of an unstructured grid flow solver to planes, trains and automobiles

Rampant, an unstructured flow solver developed at Fluent Inc., is used to compute three-dimensional, viscous, turbulent, compressible flow fields within complex solution domains. Rampant is an explicit, finite-volume flow solver capable of computing flow fields using either triangular (2d) or tetrahedral (3d) unstructured grids. Local time stepping, implicit residual smoothing, and multigrid techniques are used to accelerate the convergence of the explicit scheme. The paper describes the Rampant flow solver and presents flow field solutions about a plane, train, and automobile.

Spragle, Gregory S.↗
NASA NTRS1992

NASA's commercial space program

This paper will review the goals, status and progress of NASA's commercial space development program administered by the Office of Commercial Programs (OCP). The technologies and flight programs underway by NASA's Centers for Commercial Development (CCDS), NASA's field centers, and the NASA/Industry Joint Endeavor Programs will be summarized. A summary of completed and upcoming commercial payload activities on Shuttle, suborbital rockets, and orbital ELV's will be provided. The new commercial infrastructure and transportation initiatives will be discussed including the Wake Shield Facility, Consort and Joust suborbital rocket programs, the COMET orbital and recovery program, and the Commercial Middeck Accommodation Module Program with Spacehab Inc. Finally, the Commercial Space Station Freedom Program planned by OCP will be reviewed.

Ott, Richard H.↗
NASA NTRS1991

GaAs monolithic R.F. modules for SARSAT distress beacons

Monolithic GaAs UHF components for use in SARSAT Emergency Distress beacons are under development by Microwave Monolithics, Inc., Simi Valley, CA. The components include a bi-phase modulator, driver amplifier, and a 5 watt power amplifier.

Cauley, Michael A.↗
NASA NTRS1992

HFAST - A harmonic analysis program for Stirling cycles

HFAST is a general-purpose third-order harmonic analysis and design program for predicting the cyclic-steady state thermodynamic performance of Stirling cycles. It represents the state-of-the-art results of years of research efforts at Mechanical Technology Inc. (MTI) in the development of Stirling cycle machines. The code has been extensively used at MTI to support the development of both free-piston and kinematic Stirling cycle machines. Lately, HFAST has undergone many major improvements, both in the analysis method and in the user's interface. This paper presents a brief description of the current analysis method used in HFAST.

Huang, S. C.↗
NASA NTRS1993

The Galileo solar redshift experiment

From the October 1989 launch to the first December 1990 earth gravity assist, we regularly obtained frequency measurements of the spacecraft clock - an ultrastable crystal oscillator (USO) supplied by Frequency Electronics, Inc. The solar gravitational redshift in frequency was readily detectable, and because of the unique variations in heliocentric distance we could separate the general relativistic effects from the USO's intrinsic frequency variations. We have verified the total frequency shift predicted by general relativity to 0.5 percent accuracy, and the solar gravitational redshift to 1 percent accuracy.

Krisher, Timothy P.↗
NASA NTRS1993

Six-degree-of-freedom active vibration isolation using a Stewart platform mechanism

The design and control problems of a class of multidegree-of-freedom vibration isolation systems (VISs) based on a Stewart platform mechanism are studied. A prototype of a six-degree-of-freedom VIS for precision control of a wide range of space-based structures implemented in Intelligent Automation, Inc. is described. The feasibility of using a Stewart platform to achieve 6-degree-of-freedom vibration control in space applications is shown. A new Terfenol-D actuator characterized by significantly longer stroke than any commercially available Terfenol-D actuator and direct flux and strain sensors integral to the actuator is described.

Geng, Zheng↗
NASA NTRS1986

A prototype expert system in OPS5 for data error detection

A prototype expert system was developed in the OPS5 language to perform error checking on data which spacecraft builders/users supply to NASA GSFC for processing on the Communications Link Analysis and Simulation System (CLASS) computer. This prototype expert system, called Trajectory Preprocessing System (TRAPS), contains 49 rules and at present runs on an IBM PC in the OPS5+ software package from Artelligence, Inc. In its operational phase, TRAPS will run in the Oak Ridge Production Language (ORPL) on the CLASS computer (a Perkin-Elmer 3244 supermini). ORPL, an implementation of OPS5 by the Oak Ridge National Laboratory in MULTOFORTH on a Hewlett-Packard 9836 desktop computer, is now being ported to SS-FORTH on the CLASS computer. This paper discusses the expert system problem domain, development approach, tools, results and future plans stemming from the TRAPS project.

Rash, James↗
NASA NTRS1988

A comparison of two OTVs

For a low Earth orbit (LEO) to geosynchronous orbit (GEO) mission scenario, it can be shown that both a chemically-propelled, aerobraked orbital transfer vehicle (OTV), and a high-thrust, nuclear OTV use approximately 50 percent less propellant than a comparable, chemical OTV. At the University of Virginia two teams worked on designs for these types of OTVs. One group formed WWSR Inc. and worked on the aerobraked OTV, which was named Project Orion. The other group, named MOVERS, collaborated on the design for the nuclear engine OTV. This report will briefly review the nature and specifics of their work. This will summarize each of these propellant systems and their corresponding cost savings. It will also highlight the strengths and weaknesses of each OTV concept.

Source record↗
NASA NTRS1989

The design of a commercial space infrastructure

Space Services and Logistics, Inc. represents the complete engineering design of a technically and financially viable commercial space company. The final proposal offers an economically sound program of space vehicles and systems designed to substantially affect a variety of space markets and produce a vertically integrated structure within the next 20 years. Throughout this design process, particular stress has been placed on attaining the highest possible levels of safety and reliability. The final program financial design requires a considerable initial outlay, but promises a relatively quick return on invested capital, culminating in large annual profits by the end of the 20-year scope of the cost outlook. The overall design has been extensively researched and was primarily driven by the present and near-term projected market demands for services uniquely or competitively offered only by space-oriented operations. Heretofore, available capabilities, rather than these market demands, have determined the degree and type of commercial market access. Removing this limitation through extensive use of modularity and reconfigurability allows the company to gear itself to the market, while still remaining extremely competitive with existing systems. The markets identified as lucrative, and that have governed much of the design requirements, are: low-cost launch services to LEO over a wide range of payload masses and inclinations; upper stage payload delivery from LEO to GEO; manned space operations and human transport to and from orbit; EVA assembly and maintenance of large space structures; satellite servicing and repair by both humans and telerobotic operations; a line of customized satellites designed for extended life and capable of reconfiguration or technology upgrade on orbit; small-scale microgravity experimentation and manufacturing supported by spacecraft retrieval capabilities for experimental specimens and manufactured goods; and a full-range of payload integration, testing, design, and support services before launch and once in orbit.

Source record↗
NASA NTRS1993

CAFS: A Cesium Atomic Frequency Standard for GPS block IIR

Kernco, Inc. was selected to design the Cesium Atomic Frequency Standards (CAFS) for the GPS Block IIR NAVSTAR satellites. These spacecraft are scheduled to be launched in the mid-1990's to replenish and upgrade the existing constellation of Global Positioning System satellites. The Block IIR CAFS output frequency is 13.4003378 MHz, the 686th submultiple of the cesium atomic resonance frequency. Using an integer submultiple simplifies the design of the atomic frequency standard's rf multiplier circuits, eliminating the secondary frequency synthesizer needed in previous designs. The GPS Block IIR CAFS design, particularly the improvements made on our earlier Block II design is described. Test results are included.

Wisnia, Jeffry A.↗
NASA NTRS1993

On-orbit refueling

During the past decade, both NASA and the DOD have conducted numerous space servicing studies. These studies have shown that fluid resupply of on-orbit spacecraft is feasible and would allow for extended spacecraft utilization. In order to prove that the studies have validity, an on-orbit flight demonstration of automatic fluid resupply is required. To embark on this flight demonstration, the system concepts, operational procedures, and conceptual service and target vehicles must be identified. Hernandez Engineering, Inc. (HEI), under the direction of the Space Servicing System Project Office of the NASA/JSC New Initiatives Office, has conducted a systems engineering and integration study. The study objective was to develop preliminary concepts for a flight demonstration of automatic rendezvous, proximity operations, capture, and fluid transfer utilizing servicer and target vehicles. The results show that a servicer vehicle/target kit can be launched to orbit with an ELV and automatically rendezvous and dock with the explorer platform (EP). The servicer vehicle can then separate from the EP/kit, perform proximity maneuvers, redock with the EP/kit, and perform fluid transfer operations. After the on-orbit flight demonstration is completed, the servicer/kit can be separated from the EP and be deorbited into the Earth's atmosphere.

Moore, James S.↗
NASA NTRS1993

Advanced Turbine Technology Applications Project (ATTAP)

This report is the fifth in a series of Annual Technical Summary Reports for the Advanced Turbine Technology Applications Project (ATTAP), sponsored by the U.S. Department of Energy (DOE). The report was prepared by Garrett Auxiliary Power Division (GAPD), a unit of Allied-Signal Aerospace Company, a unit of Allied Signal, Inc. The report includes information provided by Garrett Ceramic Components, and the Norton Advanced Ceramics Company, (formerly Norton/TRW Ceramics), subcontractors to GAPD on the ATTAP. This report covers plans and progress on ceramics development for commercial automotive applications over the period 1 Jan. through 31 Dec. 1992. Project effort conducted under this contract is part of the DOE Gas Turbine Highway Vehicle System program. This program is directed to provide the U.S. automotive industry the high-risk, long-range technology necessary to produce gas turbine engines for automobiles with reduced fuel consumption, reduced environmental impact, and a decreased reliance on scarce materials and resources. The program is oriented toward developing the high-risk technology of ceramic structural component design and fabrication, such that industry can carry this technology forward to production in the 1990's. The ATTAP test bed engine, carried over from the previous AGT101 project, is being used for verification testing of the durability of next generation ceramic components, and their suitability for service at Reference Powertrain Design conditions. This document reports the technical effort conducted by GAPD and the ATTAP subcontractors during the fifth year of the project. Topics covered include ceramic processing definition and refinement, design improvements to the ATTAP test bed engine and test rigs, and the methodology development of ceramic impact and fracture mechanisms. Appendices include reports by ATTAP subcontractors in the development of silicon nitride materials and processes.

Source record↗
NASA NTRS1988

Novel oxygen atom source for material degradation studies

Physical Sciences Inc. (PSI) has developed a high flux pulsed source of energetic (8 km/s) atomic oxygen to bombard specimens in experiments on the aging and degradation of materials in a low earth orbit environment. The proof-of-concept of the PSI approach was demonstrated in a Phase 1 effort. In Phase 2 a large O-atom testing device (FAST-2) has been developed and characterized. Quantitative erosion testing of materials, components, and even small assemblies (such as solar cell arrays) can be performed with this source to determine which materials and/or components are most vulnerable to atomic oxygen degradation. The source is conservatively rated to irradiate a 100 sq cm area sample at greater than 10(exp 17) atoms/s, at a 10 Hz pulse rate. Samples can be exposed to an atomic oxygen fluence equivalent to the on-orbit ram direction exposure levels incident on Shuttle surfaces at 250 km during a week-long mission in a few hours.

Krech, R. H.↗
NASA NTRS1992

Propulsion simulator for magnetically-suspended wind tunnel models

In order to demonstrate the measurement of aerodynamic forces/moments, including the effects of exhaust jets in Magnetic Suspension and Balance System (MSBS) wind tunnels, two propulsion simulator models were developed at Physical Sciences Inc. (PSI). Both the small-scale model (1 in. diameter X 8 in. long) and the large-scale model (2.5 in. diameter X 15 in. long) employed compressed, liquefied carbon dioxide as a propellant. The small-scale simulator, made from a highly magnetizable iron alloy, was demonstrated in the 7 in. MSBS wind tunnel at the University of Southampton. It developed a maximum thrust of approximate 1.3 lbf with a 0.098 in. diameter nozzle and 0.7 lbf with a 0.295 in. diameter nozzle. The Southampton MSBS was able to control the simulator at angles-of attack up to 20 deg. The large-scale simulator was demonstrated to operate in both a steady-state and a pulse mode via a miniaturized solinoid valve. It developed a stable and repeatable thrust of 2.75 lbf over a period of 4s and a nozzle pressure ratio (NPR) of 5.

Joshi, P. B.↗
NASA NTRS1991

Control algorithm implementation for a redundant degree of freedom manipulator

This project's purpose is to develop and implement control algorithms for a kinematically redundant robotic manipulator. The manipulator is being developed concurrently by Odetics Inc., under internal research and development funding. This SBIR contract supports algorithm conception, development, and simulation, as well as software implementation and integration with the manipulator hardware. The Odetics Dexterous Manipulator is a lightweight, high strength, modular manipulator being developed for space and commercial applications. It has seven fully active degrees of freedom, is electrically powered, and is fully operational in 1 G. The manipulator consists of five self-contained modules. These modules join via simple quick-disconnect couplings and self-mating connectors which allow rapid assembly/disassembly for reconfiguration, transport, or servicing. Each joint incorporates a unique drive train design which provides zero backlash operation, is insensitive to wear, and is single fault tolerant to motor or servo amplifier failure. The sensing system is also designed to be single fault tolerant. Although the initial prototype is not space qualified, the design is well-suited to meeting space qualification requirements. The control algorithm design approach is to develop a hierarchical system with well defined access and interfaces at each level. The high level endpoint/configuration control algorithm transforms manipulator endpoint position/orientation commands to joint angle commands, providing task space motion. At the same time, the kinematic redundancy is resolved by controlling the configuration (pose) of the manipulator, using several different optimizing criteria. The center level of the hierarchy servos the joints to their commanded trajectories using both linear feedback and model-based nonlinear control techniques. The lowest control level uses sensed joint torque to close torque servo loops, with the goal of improving the manipulator dynamic behavior. The control algorithms are subjected to a dynamic simulation before implementation.

Cohan, Steve↗
NASA NTRS1992

Measuring quality progress

The study by the American Productivity & Quality Center (APQC) was commissioned by Loral Space Information Systems, Inc. and the National Aeronautics and Space Administration (NASA) to evaluate internal assessment systems. APQC benchmarked approaches to the internal assessment of quality management systems in three phases. The first phase included work conducted for the International Benchmarking Clearinghouse (IBC) and consisted of an in-depth analysis of the 1991 Malcolm Baldrige National Quality Award criteria. The second phase was also performed for the IBC and compared the 1991 award criteria among the following quality awards: Deming Prize, Malcolm Baldrige National Quality Award, The President's Award for Quality and Productivity Improvement, The NASA Excellence Award (The George M. Lowe Trophy) for Quality and Productivity Improvement and the Shigeo Shingo Award for Excellence in Manufacturing. The third phase compared the internal implementation approaches of 23 companies selected from American industry for their recognized, formal assessment systems.

Lambert, Larry D.↗