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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Environmental Measurements Session summaries

Emphasis was placed on data from payloads flown on the subject flights including results from the Induced Environment Contamination monitor (IECM). Brief summaries of the vibroacoustics, loads, electromagnetic and thermal aspects of the environment, as derived from Shuttle system measurements, were presented primarily to indicate where the environment was different than observed and, therefore, where specification changes may be forthcoming. In addition, brief summaries of two somewhat unexpected effects, the vehicle glow and interaction between the low Earth environment and Shuttle payload by materials were presented as an aid in interpreting other environmental data. Papers for each payload/experiment involved in Shuttle flights were presented essentially in flight related chronological order. A significant portion of time was allocated for presentation of IECM data since this payload was flown on STS-2, STS-3, and STS-4 and, therefore, represents the largest data base relative to the contamination environment. Summaries of papers are presented.

Lehmann, J.↗
NASA NTRS1983

Introductory comments

Vibroacoustic and thermal environment data gathered from the first three flights of the space shuttle are presented. The characterization of the particulate, gaseous, and electromagnetic emissions associated with the shuttle flight is emphasized. Measurements of vehicle glow light emissions and material effects (mass loss) due to the low Earth environment interactions with the shuttle vehicle are presented.

Leger, L. J.↗
NASA NTRS1984

Investigation of articulated panel dynamics

An articulated panel dynamics experiment to evaluate present analysis and ground test methods as well as damping effectiveness is proposed. The experiment uses an existing panel design which was extensively analyzed and tested. These data provide a firm basis for evaluating the adequacy of panel analysis and ground test methodology. The key issues for future large space structure panel designs are addressed: the critical launch transient and vibroacoustic loading; the deployment analysis adequacy including air and gravitational effects; and the orbital resonant frequencies and mode shapes of deployed panel assemblies. By using an existing mature design that was thoroughly tested, the effort can focus on correlation of actual flight results with existing predictions. A second panel assembly incorporating passive damping is proposed to provide a direct measure of damped panel benefits that can be obtained. These benefits include: reduced launch loads and responses; and highly damped deployed modes. Existing space-qualified viscoelastic epoxy, in combination with composite materials or an alternate more effective damping material, will be used.

Stahle, C. V., Jr.↗
NASA NTRS1984

Shuttle payload bay dynamic environments: Summary and conclusion report for STS flights 1-5 and 9

The vibration, acoustic and low frequency loads data from the first 5 shuttle flights are presented. The engineering analysis of that data is also presented. Vibroacoustic data from STS-9 are also presented because they represent the only data taken on a large payload. Payload dynamic environment predictions developed by the participation of various NASA and industrial centers are presented along with a comparison of analytical loads methodology predictions with flight data, including a brief description of the methodologies employed in developing those predictions for payloads. The review of prediction methodologies illustrates how different centers have approached the problems of developing shuttle dynamic environmental predictions and criteria. Ongoing research activities related to the shuttle dynamic environments are also described. Analytical software recently developed for the prediction of payload acoustic and vibration environments are also described.

Oconnell, M.↗
NASA NTRS1985

Overview: Human Factors Issues in Space Station Architecture

An overview is presented of human factors issues in space station architecture. The status of the space station program is given. Habitability concerns such as vibroacoustics, lighting systems, privacy and work stations are discussed in detail.

Cohen, M. M.↗
NASA NTRS1984

A correlation of scale model and flight aeroacoustic data for the Space Shuttle vehicle

A correlation is presented between aeroacoustic data acquired in the early Space Shuttle flights and in the various scale model tests from which the Shuttle vibroacoustic design environments were derived. These are the external acoustic data on the vehicle elements at liftoff, during the transonic and maximum dynamic pressure period of ascent flight, and during spent SRB reentry. The maximum external acoustic environment on the Shuttle elements in a given 1/3-octave frequency band comes from one of these critical flight regimes. The data correlation is seen to be good, testifying to adequate scale model measurement and test techniques. Some of the more salient features of the scale model test programs are described.

Dougherty, N. S.↗
NASA NTRS1986

Particulate contaminant relocation during shuttle ascent

The dislodgement, venting, and redeposition of particles on a surface in the shuttle bay by the vibroacoustic, gravitational, and aerodynamic forces present during shuttle ascent have been investigated. The particles of different sizes which are displaced, vented, and redistributed have been calculated; and an estimate of the increased number of particles on certain surfaces and the decrease on others has been indicated. The average sizes, velocities, and length of time for certain particles to leave the bay following initial shuttle doors opening and thermal tests have been calculated based on indirect data obtained during several shuttle flights. Suggestions for future measurements and observations to characterize the particulate environment and the techniques to limit the in-orbit particulate contamination of surfaces and environment have been offered.

Scialdone, J. J.↗
NASA NTRS1987

Space station interior noise analysis program

Documentation is provided for a microcomputer program which was developed to evaluate the effect of the vibroacoustic environment on speech communication inside a space station. The program, entitled Space Station Interior Noise Analysis Program (SSINAP), combines a Statistical Energy Analysis (SEA) prediction of sound and vibration levels within the space station with a speech intelligibility model based on the Modulation Transfer Function and the Speech Transmission Index (MTF/STI). The SEA model provides an effective analysis tool for predicting the acoustic environment based on proposed space station design. The MTF/STI model provides a method for evaluating speech communication in the relatively reverberant and potentially noisy environments that are likely to occur in space stations. The combinations of these two models provides a powerful analysis tool for optimizing the acoustic design of space stations from the point of view of speech communications. The mathematical algorithms used in SSINAP are presented to implement the SEA and MTF/STI models. An appendix provides an explanation of the operation of the program along with details of the program structure and code.

Stusnick, E.↗
NASA NTRS1986

Redistribution of particulates in shuttle bay during launch

The dislodgement, venting, and redeposition of particles on a surface in the shuttle bay by the vibroacoustic, gravitational, and aerodynamic forces present during shuttle ascent were investigated. The particles of different sizes which are displaced, vented, and redistributed were calculated. An estimate of the increased number of particles on certain surfaces and the decrease on others is indicated. The average sizes, velocities, and length of time for certain particles to leave the bay following initial shuttle doors opening and thermal tests were calculated based on indirect data obtained during several shuttle flights.

Scialdone, John J.↗
NASA NTRS1987

Particulate contaminant relocation during shuttle ascent

The dislodgement, venting, and redeposition of particles on a surface in the shuttle bay by the vibroacoustic, gravitational, and aerodynamic forces present during shuttle ascent have been investigated. The particles of different sizes which are displaced, vented, and redistributed have been calculated; and an estimate of the increased number of particles on certain surfaces and the decrease on others has been indicated. The average sizes, velocities, and length of time for certain particles to leave the bay following initial shuttle doors opening and thermal tests have been calculated based on indirect data obtained during several shuttle flights. Suggestions for future measurements and observations to characterize the particulate environment and the techniques to limit the in-orbit particulate contamination of surfaces and environment have been offered.

Scialdone, John J.↗
NASA NTRS1989

Creating a VAPEPS database: A VAPEPS tutorial

A procedural method is outlined for creating a Vibroacoustic Payload Environment Prediction System (VAPEPS) Database. The method of presentation employs flowcharts of sequential VAPEPS Commands used to create a VAPEPS Database. The commands are accompanied by explanatory text to the right of the command in order to minimize the need for repetitive reference to the VAPEPS user's manual. The method is demonstrated by examples of varying complexity. It is assumed that the reader has acquired a basic knowledge of the VAPEPS software program.

Graves, George↗
NASA NTRS1989

An overview of the Space Station Freedom environmental health system

The proposed environmental health system (EHS) designed for the closed environment of the Space Station is examined. The internal contamination control and environmental health considerations for the Space Station are discussed. The microbiology, toxicology, water quality, radiological health, vibroacoustics, and barothermal physiology subsystems of the EHS are described. Proposed capabilities of the EHS are: the environmental sample collection, processing, and analysis of the breathing atmosphere, potable and hygiene water, and internal surfaces.

Richard, Elizabeth E.↗
NASA NTRS1989

Noise environment reduction foam spheres in space

The advent of lightweight fairings for new spacecraft and the increased thrust of new launch vehicles have intensified the need for better techniques for predicting and for reducing the low frequency noise environment of spacecraft at liftoff. This paper presents a VAPEPS (VibroAcoustic Payload Environment Prediction System) parametrical analysis of the noise reduction of spacecraft fairings and explores a novel technique for increasing the low frequency noise reduction of lightweight fairing by approximately 10 dB.

Scharton, Terry↗
NASA NTRS1990

Development of the Space Station Freedom Environmental Health System

The Environmental Health System (EHS), a subsystem of the Space Station Freedom (SSF) Crew Health Care System, was established to ensure that crewmembers will have a safe and healthy environment in which to live and work. EHS is comprised of six subsystems: Microbiology, Toxicology, Water Quality, Radiological Health, Vibroacoustics, and Barothermal Physiology. Each subsystem contributes to the overall functions of the EHS including environmental planning, environmental monitoring, environmental monitoring, environmental health assessments, and operations support. The EHS will provide hardware for monitoring the air, water, and internal surfaces of Freedom, including capabilities for inflight sample collection, processing, and analysis. The closed environment of SSF, and its dependence on recycled air and water, will necessitate a reliable monitoring system to alert crewmembers if contamination levels exceed the maximum allowable limits established to ensure crew health and safety. This paper describes the functions and hardware design status of the EHS.

Richard, Elizabeth E.↗
NASA NTRS1991

Redistribution of particulates on a payload during flight ascent

The dislodgement, venting, and redeposition of particles on a surface caused by the vibroacoustic, gravitational, and aerodynamic forces are estimated and the resulting areal obscurations of the surface are calculated. The data on particle redistribution estimated to occur during a Shuttle launch are employed to estimate the obscuration of a spacecraft's star tracker, as it is carried into orbit by the Shuttle. The approach used for that calculation is generalized so that it can be employed for other applications where either the Shuttle or an Expendable Launch Vehicle (ELV) is employed for launch. Approaches for evaluating particle redistribution for other applications and for general use are indicated.

Scialdone, John J.↗