Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “test procedure”

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.

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

At least 1,207 records · Page 67

Analysis of wind-tunnel stability and control tests in terms of flying qualities of full-scale airplanes

The analysis of results of wind-tunnel stability and control tests of powered airplane models in terms of the flying qualities of full-scale airplanes is advocated. In order to indicated the topics upon which comments are considered desirable in the report of a wind-tunnel stability and control investigation and to demonstrate the nature of the suggested analysis, the present NACA flying-qualities requirements are discussed in relation to wind-tunnel tests. General procedures for the estimation of flying qualities from wind-tunnel tests are outlined.

Kayten, Gerald G↗

Lunar mass spectrometer test program

The procedures are described along with results obtained in a test program conducted to demonstrate the performance of a candidate lunar mass spectrometer. The instrument was designed to sample and measure gases believed to exist in the lunar atmosphere at the surface. The subject instrument consists of a cold cathode ion source, a small quadrupole mass analyzer and an off axis electron multiplier ion counting detector. The major program emphasis was placed on demonstrating instrument resolution, sensitivity and S/N ratio over the mass range 0-150 amu and over a partial pressure range from 10 to the minus 9th power to 10 to the minus 13th power torr. Ultrahigh vacuum tests were conducted and the minimum detectable partial pressure for neon, argon, krypton and xenon was successfully determined for the spectrometer using isotopes of these gases. With the exception of neon, the minimum detectable partial pressure is approximately 4 x 10 to the minus 14th power torr for the above gases.

Torney, F. L.↗

Evaluation of human operator visual performance capability for teleoperator missions.

Investigation of the human operator visual performance demands of teleoperator system applications to earth-orbital missions involving visual system requirements for satellite retrieval and satellite servicing functions. The first phase of an experimental program implementing this investigation is described in terms of the overall test apparatus and procedures used, the specific tests performed, and the test results obtained.

Huggins, C. T.↗

Theoretical considerations of some nonlinear aspects of hypersonic panel flutter

A research project to analyze the effects of hypersonic nonlinear aerodynamic loading on panel flutter is reported. The test equipment and procedures for conducting the tests are explained. The effects of aerodynamic linearities on stability were evaluated by determining constant-initial-energy amplitude-sensitive stability boundaries and comparing them with the corresponding linear stability boundaries. An attempt to develop an alternative method of analysis for systems where amplitude-sensitive instability is possible is presented.

Mcintosh, S. C., Jr.↗

The Space Shuttle's testing gauntlet

The Space Shuttle verification program is detailed, with verification network flowcharts. Performance qualification tests, life endurance tests, structural verification tests, and vibration/dynamic tests of components, subsystems, and major systems at various test levels are dealt with. Ground tests, static firings of the Shuttle main engine, external-tank separation tests, ground vibration tests of vehicle mated to external tank, and main propulsion tests and test scheduling are described. Functions of the Shuttle avionics integration laboratory and electronic systems test laboratory are discussed. Test preparations and procedures for orbital flight testing, launch pad tests, and Shuttle approach- and landing-tests are described.

Mcintosh, G. P.↗

Shuttle communication systems compatibility and performance tests

The compatibility and performance of the Shuttle communications system must be certified prior to operational missions. For this purpose, NASA has established the Electronics Systems Test Laboratory (ESTL) at the Johnson Space Center. This paper discusses the Shuttle communications system compatibility and performance testing being performed in the ESTL. The ESTL system verification test philosophy, including capabilities, procedures, and unique testing equipment are summarized. Summaries of the significant results of compatibility and performance tests of the Orbiter/Space-flight Tracking and Data Network, Orbiter/Air Force Remote Tracking Station, Orbiter/Tracking and Data Relay Satellite System and Orbiter/Shuttle Launch Support System interfaces are presented. The ESTL's unique ability to locate potential communication problems and participate in the resolution of these problems are discussed in detail.

Bromley, L. K.↗

Cryogenic performance of the SIRTF prototype secondary mirror assembly

Results are presented of the first liquid helium temperature testing of the Space Infrared Telescope Facility (SIRTF) prototype Secondary Mirror Assembly (PSMA). Attention is given to the key requirements of PSMA, its design, and the test instrumentation and procedures. Results of preliminary tests completed to date showed that the design of the PSMA forms a very strong basis for meeting the SIRTF requirements.

Stier, M. T.↗

Humidity effects on soluble core mechanical and thermal properties (polyvinyl alcohol/microballoon composite) type CG extendospheres, volume 2

This document constitutes the final report for the study of humidity effects and loading rate on soluble core (PVA/MB composite material) mechanical and thermal properties under Contract No. 100345. This report describes test results procedures employed, and any unusual occurrences or specific observations associated with this test program. The primary objective of this work was to determine if cured soluble core filler material regains its tensile and compressive strength after exposure to high humidity conditions and following a drying cycle. Secondary objectives include measurements of tensile and compressive modulus, and Poisson's ratio, and coefficient of thermal expansion (CTE) for various moisture exposure states. A third objective was to compare the mechanical and thermal properties of the composite using 'SG' and 'CG' type extendospheres. The proposed facility for the manufacture of soluble cores at the Yellow Creek site incorporates no capability for the control of humidity. Recent physical property tests performed with the soluble core filler material showed that prolonged exposure to high humidity significantly degradates in strength. The purpose of these tests is to determine if the product, process or facility designs require modification to avoid imparting a high risk condition to the ASRM.

Source record↗

Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: METSAT (S/N 108) AMSU-A1 Receiver Assemblies, P/N 1356429-1 S/N F05 and P/N 1356409-1 S/N F05

This is the Performance Verification Report, METSAT (S/N 108) AMSU-A1 Receiver Assemblies P/N 1356429-1 S/N F05 and P/N 1356409-1 S/N F05, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A). The ATP for the AMSU-A Receiver Subsystem, AE-26002/6A, is prepared to describe in detail the configuration of the test setups and the procedures of the tests to verify that the receiver subsystem meets the specifications as required either in the AMSU-A Instrument Performance and Operation Specifications, S-480-80, or in AMSU-A Receiver Subsystem Specifications, AE-26608, derived by the Aerojet System Engineering. Test results that verify the conformance to the specifications demonstrate the acceptability of that particular receiver subsystem.

Haigh, R.↗

Assessment of Technologies for the Space Shuttle External Tank Thermal Protection System and Recommendations for Technology Improvement - Part III: Material Property Characterization, Analysis, and Test Methods

The objective of this report is to contribute to the independent assessment of the Space Shuttle External Tank Foam Material. This report specifically addresses material modeling, characterization testing, data reduction methods, and data pedigree. A brief description of the External Tank foam materials, locations, and standard failure modes is provided to develop suitable background information. A review of mechanics based analysis methods from the open literature is used to provide an assessment of the state-of-the-art in material modeling of closed cell foams. Further, this report assesses the existing material property database and investigates sources of material property variability. The report presents identified deficiencies in testing methods and procedures, recommendations for additional testing as required, identification of near-term improvements that should be pursued, and long-term capabilities or enhancements that should be developed.

Gates, Thomas S.↗

Quick-and-Easy Validation of Protein–Ligand Binding Models Using Fragment-Based Semiempirical Quantum Chemistry

Electronic structure calculations in enzymes converge very slowly with respect to the size of the model region that is described using quantum mechanics (QM), requiring hundreds of atoms to obtain converged results and exhibiting substantial sensitivity (at least in smaller models) to which amino acids are included in the QM region. As such, there is considerable interest in developing automated procedures to construct a QM model region based on well-defined criteria. However, testing such procedures is burdensome due to the cost of large-scale electronic structure calculations. Here, we show that semiempirical methods can be used as alternatives to density functional theory (DFT) to assess convergence in sequences of models generated by various automated protocols. The cost of these convergence tests is reduced even further by means of a many-body expansion. We use this approach to examine convergence (with respect to model size) of protein–ligand binding energies. Fragment-based semiempirical calculations afford well-converged interaction energies in a tiny fraction of the cost required for DFT calculations. Two-body interactions between the ligand and single-residue amino acid fragments afford a low-cost way to construct a “QM-informed” enzyme model of reduced size, furnishing an automatable active-site model-building procedure. This provides a streamlined, user-friendly approach for constructing ligand binding-site models that needs neither a priori information nor manual adjustments. Extension to model-building for thermochemical calculations should be straightforward.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Testing Electronic Devices for Single-Event Upset

Report prepared describes equipment and summarizes both pretest and onsite procedures for testing of digital electronic devices for susceptibility to single-event upset. Term "single-event upset" denotes variety of temporary or permanent bit flips or latchup induced by single particles of ionizing radiation. Vacuum chamber houses device under test while exposed to ion beam. Vacuum chamber and associated equipment must be brought to ion-beam facility for test.

Nichols, D. K.↗

Experimental study of solar simulator mirror cryocontamination

The background and tasks formulation of the study of Solar Simulator collimation mirror cryocontamination in Large Thermal Vacuum Facility are outlined, research methods and experiment procedures are described, experimental relationships obtained are analyzed and practical recommendations are given. The accepted procedure of thermal vacuum tests as a rule defines the sequence of operations for verifying the spacecraft under test without taking into account measures for preventing Solar Simulator collimation mirror contamination and degradation. On the other hand, evacuation procedures is defined for conditions of achieving the required vacuum in the shortest possible time with using the available evacuation equipment at a regime close to the optimum one. Similarly, cryopanel cooling down cyclogram and test object preparation process are not analyzed from the viewpoint of ways of reducing environmental detrimental effects on thermal vacuum facility contamination-sensitive systems. Solar Simulator mirror contamination and its reflective characteristics change results in degradation of solar flux parameters and reduction of simulator continuous operation time. Methods of consideration of optical effects due to mirror surface contamination are actually missing. The effects themselves are not quite understood and data cited in literature as a rule, were obtained under conditions different from real thermal vacuum facility and therefore should be subjected to additional experimental verification. Only in the last few years contamination effect on optical surfaces degradation has been considered with using empirical relations. Mirror reflective properties degradation leads to the increase of Solar Simulator errors. This ultimately has an adverse effect on S/C ground development, schedule and cost of thermal vacuum tests. Besides, the mirror maintenance in operable state becomes more expensive. The present paper is dedicated to the study of Solar Simulator collimation mirror contamination and to the search of ways for improving the mirror design and thermal vacuum test procedure. On the basis of tests performed, recommendations are devised on reducing chamber inner-optical surfaces cryocontamination and degradation.

Galjaev, V. L.↗

A second order iteration procedure for correlation of analysis frequencies with test data

A second derivative frequency modification procedure is developed to iteratively change analysis modeling parameters for the more rapid convergence of analytically determined frequencies to those obtained by structural dynamic testing. A nonlinear system of algebraic equations in the modeling parameters is derived and a rapidly converging iterative method for their solution is presented. Numerical results obtained show that the higher order formulation and nonlinear predictor-corrector solution procedure yields results which are more rapidly convergent than those obtained using only the usual linear first-order parameter modification procedure. The proposed higher order theory also connverges in some cases when the ordinary linear theory does not.

Ojalvo, I. U.↗

Manned remote work station development article. Volume 3: Development test plan. Appendix A: Manufacturing requirements/schedule

The tests and procedures for the manned remote work station (MRWS) open cherry picker (OCP) development test article (DTA) are described to validate systems requirements and performance specifications. A development test program is outlined to evaluate key design issues and man/machine interfaces when the MRWS OCP is used in a shuttle support role of satellite servicing and in orbit construction of large structures.

Source record↗