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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 901 records · Page 50
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Preliminary test results with a Stirling Laboratory Research Engine

The Jet Propulsion Laboratory has designed, assembled, and initiated testing of a Stirling Laboratory Research Engine (SLRE). This preprototype engine provides a research tool to support the development of a broad range of analytical modeling and experimental efforts. The SLRE is a horizontally opposed, two-piston, single-acting Stirling engine with a split crankshaft drive mechanism. The paper discusses the preliminary results obtained during engine motoring tests and compares these results with two different analytical prediction models. Comparisons are made between experiment, the classical Schmidt analysis, and the JPL Stirling Cycle Analysis Model (SCAM). SCAM is a computerized one-dimensional, cyclic, compressible flow model of the SLRE and consists of a compilation of individual component subroutines. The formulation and current state of development of the SCAM program is briefly described.

Hoehn, F. W.↗
NASA NTRS2000

Wave Fluid Film Bearing Tests for an Aviation Gearbox

An oil-lubricated wave journal-thrust bearing assembly was successfully tested at conditions found in general aviation engine gearboxes. The bearing performed well at both steady state conditions and in start-stop tests. It ran stably under all loading conditions, including zero load, at all speeds up to 16 000 rpm. The bearing carried 25 percent more load than required for the gearbox application, supporting 8900 N (94 bars average pressure), and showed very good thermal stability. 450 start-stop cycles were also performed, including 350 cycles without oil supply during starting and stopping. Test results and numerical predictions were in good agreement.

Dimofte, Florin↗
NASA NTRS1991

End-effector for robotic assembly of welded truss structures in space

In June 1987, work was initiated at LaRC on end-effectors and preloaded joints for robotic truss assembly. This is part of an on-going research effort centered on a test facility that assembles 1 inch x 2 m identical struts into an 8 m diameter x 1.5 m deep platform truss. A detailed description of the test facility was published. The end-effector being used for the LaRC assembly demonstration is quite suitable for the Precision Segmented Reflector or other precision applications. These require high stiffness provided by mechanical joint preloads. Stiffness obtained in this manner is only required and provided over a load range far less than the ultimate strength of the strut tubes. Beyond this useful range, truss behavior is somewhat unpredictable. Mechanically preloaded joints of this type are less suitable for applications such as the Aero Brake where predictable strength and stiffness are required over a greater fraction of the load bearing capacity of component parts. Preliminary studies of the Aerobrake support truss indicate that struts of at least 3 different diameters and various lengths would improve performance. The double-ended end-effector currently in service is designed for only one diameter and length. Anticipated single-ended versions can accommodate varying lengths but not multiple diameters. Tradeoff considerations for welded joints relative to their mechanically preloaded counterparts are presented. Conclusions from this research are as follows: (1) repair by cut and re-weld on the original weld site should be research; (2) welded joints, though repairable, should not be used where high repair frequencies are anticipated; and (3) welded joints should be considered for an Aero Brake truss.

Brewer, William V.↗
NASA NTRS2011

Simulating New Drop Test Vehicles and Test Techniques for the Orion CEV Parachute Assembly System

The Crew Exploration Vehicle Parachute Assembly System (CPAS) project is engaged in a multi-year design and test campaign to qualify a parachute recovery system for human use on the Orion Spacecraft. Test and simulation techniques have evolved concurrently to keep up with the demands of a challenging and complex system. The primary simulations used for preflight predictions and post-test data reconstructions are Decelerator System Simulation (DSS), Decelerator System Simulation Application (DSSA), and Drop Test Vehicle Simulation (DTV-SIM). The goal of this paper is to provide a roadmap to future programs on the test technique challenges and obstacles involved in executing a large-scale, multi-year parachute test program. A focus on flight simulation modeling and correlation to test techniques executed to obtain parachute performance parameters are presented.

Morris, Aaron L.↗
NASA NTRS1986

Experimental investigation of rotorcraft hub and shaft fairing drag reduction

A wind-tunnel test was conducted to obtain data on several rotorcraft hub and shaft fairing drag reduction configurations. Aerodynamic loads and moments were acquired for each test configuration. Limited wake pressure measurements and flow visualization (tuft) photographs were obtained for some configurations. All hub and shaft fairing configurations were tested on a 1/5-scale XH-59A model fuselage. Both coaxial and single rotor configurations were tested. All rotor assemblies were modeled with nonrotating hardware. The drag reduction methods tested included cambered elliptical hub fairings, several different shaft fairings, and strakes. Test data show that significant drag reductions can be attained with certain fairing configurations. The lowest drag values for the single rotor configurations were obtained for a cambered elliptical hub fairing with a large thickness airfoil shaft fairing. The lowest coaxial configuration drag values were obtained with cambered elliptical hub fairings and a long chord intermediate shaft fairing.

Young, L. A.↗
NASA NTRS2011

Component-Level Electronic-Assembly Repair (CLEAR) Synthetic Instrument Capabilities Assessment and Test Report

The role of synthetic instruments (SIs) for Component-Level Electronic-Assembly Repair (CLEAR) is to provide an external lower-level diagnostic and functional test capability beyond the built-in-test capabilities of spacecraft electronics. Built-in diagnostics can report faults and symptoms, but isolating the root cause and performing corrective action requires specialized instruments. Often a fault can be revealed by emulating the operation of external hardware. This implies complex hardware that is too massive to be accommodated in spacecraft. The SI strategy is aimed at minimizing complexity and mass by employing highly reconfigurable instruments that perform diagnostics and emulate external functions. In effect, SI can synthesize an instrument on demand. The SI architecture section of this document summarizes the result of a recent program diagnostic and test needs assessment based on the International Space Station. The SI architecture addresses operational issues such as minimizing crew time and crew skill level, and the SI data transactions between the crew and supporting ground engineering searching for the root cause and formulating corrective actions. SI technology is described within a teleoperations framework. The remaining sections describe a lab demonstration intended to show that a single SI circuit could synthesize an instrument in hardware and subsequently clear the hardware and synthesize a completely different instrument on demand. An analysis of the capabilities and limitations of commercially available SI hardware and programming tools is included. Future work in SI technology is also described.

Oeftering, Richard C.↗
NASA NTRS2009

Development and Testing of the Orion CEV Parachute Assembly System (CPAS)

The Crew Exploration Vehicle (CEV) is an element of the Constellation Program that includes launch vehicles, spacecraft, and ground systems needed to embark on a robust space exploration program. As an anchoring capability of the Constellation Program, the CEV shall be human-rated and will carry human crews and cargo from Earth into space and back again. Coupled with transfer stages, landing vehicles, and surface exploration systems, the CEV will serve as an essential component of the architecture that supports human voyages to the Moon and beyond. In addition, the CEV will be modified, as required, to support International Space Station (ISS) mission requirements for crewed and pressurized cargo configurations. Headed by Johnson Space Center (JSC), NASA selected Jacobs Engineering as the support contractor to manage the overall CEV Parachute Assembly System (CPAS) program development. Airborne Systems was chosen to develop the parachute system components. General Dynamics Ordnance and Tactical Systems (GD-OTS) was subcontracted to Airborne Systems to provide the mortar systems. Thus the CPAS development team of JSC, Jacobs, Airborne Systems and GD-OTS was formed. The CPAS team has completed the first phase, or Generation I, of the design, fabrication, and test plan. This paper presents an overview of the CPAS program including system requirements and the development of the second phase, known as the Engineering Development Unit (EDU) architecture. We also present top level results of the tests completed to date. A significant number of ground and flight tests have been completed since the last CPAS presentation at the 2007 AIAA ADS Conference.

Lichodziejewski, David↗
NASA NTRS1990

Automated assembly of large space structures

A research program to evaluate telerobotic methods for inspace assembly of large truss structures has been initiated at the NASA Langley Research Center. A commercial robot is mounted on a carriage positioning system and a tetrahedral truss, which is composed of 102 members each 2 m long, is assembled on a rotating motion-base. The facility system is described including details of characterization tests on the truss structure. The current status of the assembly tests is discussed and observations from these tests indicate that no problems have been encountered that would prohibit automated telerobotic assembly from being a viable inspace construction method.

Rhodes, Marvin D.↗
NASA NTRS2005

Performance Qualification Test of the ISS Water Processor Assembly (WPA) Expendables

The Water Processor Assembly (WPA) for use on the International Space Station (ISS) includes various technologies for the treatment of waste water. These technologies include filtration, ion exchange, adsorption, catalytic oxidation, and iodination. The WPA hardware implementing portions of these technologies, including the Particulate Filter, Multifiltration Bed, Ion Exchange Bed, and Microbial Check Valve, was recently qualified for chemical performance at the Marshall Space Flight Center. Waste water representing the quality of that produced on the ISS was generated by test subjects and processed by the WPA. Water quality analysis and instrumentation data was acquired throughout the test to monitor hardware performance. This paper documents operation of the test and the assessment of the hardware performance.

Carter, Layne↗
NASA NTRS1979

Flight test evaluation of an RAF high altitude partial pressure protective assembly

A partial pressure suit was evaluated during tests in an F-104 and F-15 as a protective garment for emergency descents. The garment is an pressure jerkin and modified anti-g suit combined with an oronasal mask. The garment can be donned and doffed at the aircraft to minimize thermal buildup. The oronasal mask was favored by the pilots due to its immobility on the face during high g-loading. The garment was chosen to provide optimum dexterity for the pilot, which is not available in a full pressure suit, while protecting the pilot at altitudes up to 18,288 meters, during a cabin decompression, and subsequent aircraft descent. During cabin decompressions in the F-104 and F-15, cabin pressure altitude was measured at various aircraft angles of attack, Mach numbers, and altitudes to determine the effect of the aerodynamic slipstream on the cabin altitude.

Ashworth, G. R.↗
NASA NTRS2011

Design, Development and Testing of the GMI Reflector Deployment Assembly

The GMI Reflector Deployment Assembly (RDA) is an articulating structure that accurately positions and supports the main reflector of the Global Microwave Imager (GMI) throughout the 3 year mission life. The GMI instrument will fly on the core Global Precipitation Measurement (GPM) spacecraft and will be used to make calibrated radiometric measurements at multiple microwave frequencies and polarizations. The GPM mission is an international effort managed by the National Aeronautics and Space Administration (NASA) to improve climate, weather, and hydrometeorological predictions through more accurate and frequent precipitation measurements1. Ball Aerospace and Technologies Corporation (BATC) was selected by NASA Goddard to design, build, and test the GMI instrument. The RDA was designed and manufactured by ATK Aerospace Systems Group to meet a number of challenging packaging and performance requirements. ATK developed a flight-like engineering development unit (EDU) and two flight mechanisms that have been delivered to BATC. This paper will focus on driving GMI instrument system requirements, the RDA design, development, and test activities performed to demonstrate that requirements have been met.

Guy, Larry↗
NASA NTRS1988

A review of test results on parabolic dish solar thermal power modules with dish-mounted Rankine engines and for production of process steam

This paper presents results of development testing of various solar thermal parabolic dish modules and assemblies. Most of the tests were at modules and assemblies that used a dish-mounted, organic Rankine cycle turbine for production of electric power. Some tests were also run on equipment for production of process steam or for production of electricity using dish-mounted reciprocating steam engines. These tests indicate that early modules achieve efficiencies of about 18 percent in converting sunlight to electricity (excluding the inverter but including parasitics). A number of malfunctions occurred. The performance measurements, as well as the malfunctions and other operating experience, provided information that should be of value in developing systems with improved performance and reduced maintenance.

Jaffe, Leonard D.↗
NASA NTRS1972

Long life assurance study for manned spacecraft long life hardware. Volume 4: Special long life assurance studies

Guidelines for the selection of equipment to be used for manned spacecraft in order to assure a five year maintenance-free service life were developed. A special study was conducted to determine the adequacy of the procedures used to determine the quality and effectiveness of various components. The subjects examined are: (1) temperature cycling for acceptance of electronic assemblies; (2) accelerated testing techniques; (3) electronic part screening techniques; (4) electronic part derating practices; (5) vibration life extension of printed circuit board assemblies; and (6) tolerance funnelling and test requirements.

Source record↗
NASA NTRS1986

The AXAF technology mirror assembly program - An overview

The manufacture and testing of the Technology Mirror Assembly (TMA), a prototype Wolter I telescope scaled to the dimensions of the innermost element of the High-Resolution Mirror Assembly for the NASA Advanced X-ray Astrophysics Facility (AXAF), are reviewed. Consideration is given to the grinding, polishing, coating, and assembly of the zerodur TMA blanks, the TMA mount design, and the test procedures used at the MSFC X-ray Calibration Facility. Test results indicate FWHM resolution less than 0.5 arcsec, but with significant near-field scattering attributed to ripple; further long-lap polishing is suggested.

Wyman, Charles L.↗
NASA NTRS1974

Absolute pressure transducers for space shuttle and orbiter propulsion and control systems

A preliminary design was completed, reviewing of such subjects as: the trade studies for media isolation and one sensor vs. two sensors for two bridges; compensation resistors; unit design; hydrogen embrittlement; sealing techniques and test station design. A design substantiation phase was finished, consisting of testing of a prototype unit and fabrication technique studies. A cryogenic test station was implemented and prototype sensor cells were fabricated, sensors assembled, and cryogenic tests performed.

Bolta, J. J.↗
NASA NTRS1993

Power Reactant Storage Assembly (PRSA) (Space Shuttle). PRSA hydrogen and oxygen DVT tank refurbishment

The Power Reactant Storage Assembly (PRSA) liquid hydrogen Development Verification Test (H2 DVT) tank assembly (Beech Aircraft Corporation P/N 15548-0116-1, S/N 07399000SHT0001) and liquid oxygen (O2) DVT tank assembly (Beech Aircraft Corporation P/N 15548-0115-1, S/N 07399000SXT0001) were refurbished by Ball Electro-Optics and Cryogenics Division to provide NASA JSC, Propulsion and Power Division, the capability of performing engineering tests. The refurbishments incorporated the latest flight configuration hardware and avionics changes necessary to make the tanks function like flight articles. This final report summarizes these refurbishment activities. Also included are up-to-date records of the pressure time and cycle histories.

Source record↗
NASA NTRS2000

TransHab: NASA's Large-Scale Inflatable Spacecraft

TransHab is a, 27-foot diameter by 40-foot, lightweight inflatable habitation module for space applications. TransHab consists of a lightweight graphite-composite core, 11-foot diameter by 23-foot tall, surrounded by a 27-foot diameter inflatable shell. Originally envisioned to be the habitation module of an interplanetary transit vehicle, TransHab is currently being considered as a module for use on the International Space Station (ISS). During the past two years, several tests have been performed at the NASA/Johnson Space Center to demonstrate and prove the technologies required in building a large-scale inflatable habitation module. This paper discusses the results of these tests which including the following: 1) a structural integrity development test article hydJ"Ostatically tested to four times ambient pressure, 2) a full-scale development test article manufactured, assembled, folded and deployed at vacuum, and 3) extensive hypervelocity impact testing of the micro meteoroid and orbital debris protection system.

delaFuente, Horacio↗