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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 1,081 records · Page 60
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Development of a NASA standard gas generator

The goals of the NASA Standard Gas Generator (NSGG) Program are to create a NASA standard gas generating cartridge, characterize its performance, and make it readily available to users. A cartridge within the same envelope as the NASA Standard Initiator (NSI) has the greatest potential use. This potential use is described in viewgraph form. Our approach for NSGG development and qualification was planned to be conducted in several phases. Test methods were developed to evaluate output performance for a variety of potential applications. A feasibility study using modified NSI's was accomplished. Preliminary and final development will be conducted with a delta qualification to evaluate the effects of manufacturing lots and environments. Feasibility study results, feasibility study conclusions, and future plans are presented.

Bement, Laurence J.↗
NASA NTRS1993

Preliminary results: Root cause investigation of orbital anomalies and failures in NASA standard 50 ampere-hour nickel-cadmium batteries

Two lots of NASA standard 50 A.H. Ni-Cd battery cells, manufactured by Gates Aerospace Batteries and built into batteries by McDonnell Douglas, have experienced significant performance problems. The two lots were used on the Compton Gamma Ray Observatory and the Upper Atmosphere Research Satellite. Both of these satellites are Low Earth Orbital (LEO) satellites containing batteries on a parallel bus charged to NASA standard V/T curves using a NASA standard power regulator. The following preliminary conclusions were reached: (1) several plate and cell parameters have migrated within their spec limits over the years (in some cases, from one extreme to the other); (2) several parametric relationships, not generally monitored and therefore not under specification control, have also migrated over the years; (3) many of these changes appear to have taken place as a natural consequence of changes in GE/GAB materials and processes; (4) several of these factors may be 'conspiring' to aggravate known cell failure mechanisms (factors such as heavier plate, less teflon and/or less-uniform teflon, and less electrolyte) but all are still in spec (where specs exist); (5) the weight of the evidence collected to characterize the anomalies and to characterize the negative electrode itself, strongly suggests that alterations to the structure, composition, uniformity, and efficiency of the negative electrode are at the heart of the battery performance problems currently being experienced; and (6) further investigation at all levels (plate, cell, battery, and system) continues to be warranted.

Toft, Mark R.↗
NASA NTRS1992

Helicopter simulator standards

The initial advisory circular was produced in 1984 (AC 120-XX). It was not finalized, however, because the FAR's for pilot certification did not recognize helicopter simulators and, therefore, permitted no credit for their use. That is being rectified, and, when the new rules are published, standards must be available for qualifying simulators. Because of the lack of a data base to support specification of these standards, the FAA must rely on the knowledge of experts in the simulator/training industry. A major aim of this workshop is to form a working group of these experts to produce a set of standards for helicopter training simulators.

Boothe, Edward M.↗
NASA NTRS1993

The standards process: X3 information processing systems

The topics are presented in viewgraph form and include the following: International Organization for Standards (ISO); International Electrotechnical Committee (IEC); ISO/IEC Joint Technical Committee 1 (JTC-1); U.S. interface to JTC-1; ANSI; national organizations; U.S. standards development processes; national and international standards developing organizations; regional organizations; and X3 information processing systems.

Emard, Jean-Paul↗
NASA NTRS1993

The standards process: Technical committee X3B5 digital magnetic tape

The definition of X3B5, where it fits in the national and international standards development process, and how it interfaces and influences the world community of standards developers are provided. Details concerning the focus of the committee, how it operates, and what the group sees as the future trends in the area of interchange standards utilizing the multifaceted, ubiquitous magnetic tape are presented.

Cheatham, Sam↗
NASA NTRS1992

Ultra-stable Hg(+) trapped ion frequency standard

We report the development of a fieldable frequency standard based on Hg-199(+) ions confined in a hybrid r.f./dc linear ion trap. This trap permits storage of large numbers of ions with reduced susceptibility to the second-order Doppler effect caused by the r.f. confining fields. A 160 mHz wide atomic resonance line for the 40.5 GHz clock transition is used to steer the output of a 5 MHz crystal oscillator to obtain a stability of 2 x 10 exp -15 for 24,000 s averaging times. For longer averaging intervals, measurements are limited by instabilities in available hydrogen maser frequency standards. Measurements with 37 mHz linewidth for the Hg(+) clock transition demonstrate that the inherent stability for this frequency standard is at least as good as 1 x 10 exp -15.

Prestage, J. D.↗
NASA NTRS1946

Correlation between strength properties in standard test specimens and molded phenolic parts

This report describes an investigation of the tensile, flexural, and impact properties of 10 selected types of phenolic molding materials. The materials were studied to see in what ways and to what extent their properties satisfy some assumptions on which the theory of strength of materials is based: namely, (a) isotropy, (b) linear stress-strain relationship for small strains, and (c) homogeneity. The effect of changing the dimensions of tensile and flexural specimens and the span-depth ratio in flexural tests were studied. The strengths of molded boxes and flexural specimens cut from the boxes were compared with results of tests on standard test specimens molded from the respective materials. The nonuniformity of a material, which is indicated by the coefficient of variation, affects the results of tests made with specimens of different sizes and tests with different methods of loading. The strength values were found to depend on the relationship between size and shape of the molded specimen and size and shape of the fillers. The most significant variations observed within a diversified group of materials were found to depend on the orientation of fibrous fillers. Of secondary importance was the dependence of the variability of test results on the pieces of filler incorporated into the molding powder as well as on the size of the piece. Static breaking strength tests on boxes molded from six representative phenolic materials correlated well with falling-ball impact tests on specimens cut from molded flat sheets. Good correlation was obtained with Izod impact tests on standard test specimens prepared from the molding materials. The static breaking strengths of the boxes do not correlate with the results of tensile or flexural tests on standard specimens.

MATERIALS, MONSANTO RESINOX↗
NASA NTRS1946

Standard nomenclature for airspeeds with tables and charts for use in calculation of airspeed

Symbols and definition of various airspeed terms that have been adopted as standard by the NACA subcommittee on aircraft structural design are presented. The equations, charts, and tables required in the evaluation of true airspeed, calibrated airspeed, equivalent airspeed, impact and dynamic pressures, and Mach and Reynolds numbers have been compiled. Tables of the standard atmosphere to an altitude of 65,000 feet and a tentative extension to an altitude of 100,000 feet are given along with the basic equations and constants on which both the standard atmosphere and the tentative extension are based.

Aiken, William S , Jr↗
NASA NTRS1994

Program Helps Standardize Documentation Of Software

Intelligent Documentation Management System, IDMS, computer program developed to assist project managers in implementing information system documentation standard known as NASA-STD-2100-91, NASA STD, COS-10300, of NASA's Software Management and Assurance Program. Standard consists of data-item descriptions or templates, each of which governs particular component of software documentation. IDMS helps program manager in tailoring documentation standard to project. Written in C language.

Howe, G.↗
NASA NTRS1967

Standards of conduct for NASA special government employees

NASA regulations prescribing standards of conduct for all NASA employees, including special government employees, were approved by the Civil Service Commission on September 19, 1967, and by the Administrator on October 12, 1967, and were published in the Federal Register (32 F.R. 14648-14659) on October 21, 1967. The standards of conduct regulations are issued under Executive Order 11222 of May 11, 1965 (30 F.R. 6469, 3 C.F.R. 1965 Supp.; 5 C.F.R. 735.104), and Chapter 735 of the Federal Personnel Manual. For the convenience of special government employees, those portions of the NASA standards of conduct regulations which are applicable only to special government employees, Part F and Appendixes E, F, and G, are reissued in this handbook. Except for references to 'parts,' 'subparts,' 'sections,' etc., the text is identical to that published in the Federal Register.

Source record↗
NASA NTRS1987

Standards of conduct for NASA employees

'Standards of Conduct' for employees (14 CFR Part 1207) is set forth in this handbook and is hereby incorporated in the NASA Directives System. This handbook incorporates, for the convenience of NASA employees, the regulations now in effect prescribing standards of conduct for NASA employees. These regulations set forth the high ethical standards of conduct required of NASA employees in carrying out their duties and responsibilities. These regulations have been approved by the Office of Government Ethics, Office of Personnel Management. The regulations incorporated in this handbook were first published in the Federal Register on October 21, 1967 (32 FR 14648-14659); Part B concerning the acceptance of gifts, gratuities, or entertainment was extensively revised on January 19, 1976 (41 FR 2631-2633) to clarify and generally to restrict the exceptions to the general rule against the acceptance by a NASA employee from persons or firms doing or seeking business with NASA. Those regulations were updated on January 29, 1985 (50 FR 3887) to ensure conformity to the Ethics in Government Act of 1978 regarding the public financial disclosure statement. These regulations were published in the Federal Register on June 16, 1987 (52 FR 22755-764) and a correction was printed on Sept. 28, 1987 (52 FR 36234).

John E O'Brien↗
NASA NTRS1993

Progress on GPS standardization

It has been clear for some time that a desirable and necessary step for improvement of the accuracy of GPS time comparisons is to establish GPS standards which may be adopted by receiver designers and users. For this reason, a formal body, the CCDS Group on GPS Time Transfer Standards (CGGTTS), was created in 1991. It operates under the auspices of the permanent CCDS Working Group on TAI, with the objective of recommending procedures and models for operational time transfer by the GPS common-view method. It works in close cooperation with the Subcommittee on Time of the Civil GPS Service Interface Committee. The members of the CGGTTS have met in December 1991 and in June 1992. Following these two formal meetings, a number of decisions were taken for unifying the treatment of GPS short-term data and for standardizing the format of GPS data files. A formal CGGTTS Recommendation is now being written concerning these points. This paper relates on the work carried out by the CGGTTS.

Thomas, C.↗
NASA NTRS1993

Space Generic Open Avionics Architecture (SGOAA) standard specification

The purpose of this standard is to provide an umbrella set of requirements for applying the generic architecture interface model to the design of a specific avionics hardware/software system. This standard defines a generic set of system interface points to facilitate identification of critical interfaces and establishes the requirements for applying appropriate low level detailed implementation standards to those interface points. The generic core avionics system and processing architecture models provided herein are robustly tailorable to specific system applications and provide a platform upon which the interface model is to be applied.

Wray, Richard B.↗
NASA NTRS1993

The European Space Agency standard for space packet utilisation

This paper presents the ESA concept for the use of CCSDS defined Telemetry and Telecommand Packets at the application level. These Packets are used to monitor and control remotely a space born application. This concept is defined in a Packet Utilisation Standard (PUS) which should become applicable for all ESA missions using Packets. The production of this standard is under the responsibility of an ESA standardization group called 'COES'.

Kaufeler, J.-F.↗
NASA NTRS1992

Software assurance standard

This standard specifies the software assurance program for the provider of software. It also delineates the assurance activities for the provider and the assurance data that are to be furnished by the provider to the acquirer. In any software development effort, the provider is the entity or individual that actually designs, develops, and implements the software product, while the acquirer is the entity or individual who specifies the requirements and accepts the resulting products. This standard specifies at a high level an overall software assurance program for software developed for and by NASA. Assurance includes the disciplines of quality assurance, quality engineering, verification and validation, nonconformance reporting and corrective action, safety assurance, and security assurance. The application of these disciplines during a software development life cycle is called software assurance. Subsequent lower-level standards will specify the specific processes within these disciplines.

Source record↗
NASA NTRS1994

Air Force standards for nickel hydrogen battery

The topics discussed are presented in viewgraph form and include Air Force nickel hydrogen standardization goals, philosophy, project outline, cell level standardization, battery level standardization, and schedule.

Hwang, Warren↗
NASA NTRS1994

Cesium and rubidium frequency standards status and performance on the GPS program

This paper is an update of the on-orbit operational performance of the frequency standards on the Block I GPS 8 to 11 Navstar satellites, the Block II GPS 13 to 21 Navstar satellites and the Block IIA GPS 22 to 40 Navstar satellites. A brief history of the frequency standards depicting improvements incorporated in the GPS Program with corresponding results will be presented. The frequency standards configurations from the start to the present, including the various Block IIA clock configurations will be discussed. Topics such as clock observations and long term trending analysis which could enhance on-orbit performance analysis will be covered.

Vanmelle, M. J.↗