NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsComparison Tools for Assessing the Microgravity Environment of Missions, Carriers and ConditionsThe Principal Component Spectral Analysis and the Quasi-steady Three-dimensional Histogram techniques provide the means to describe the microgravity acceleration environment of an entire mission on a single plot. This allows a straight forward comparison of the microgravity environment between missions, carriers, and conditions. As shown in this report, the PCSA and QTH techniques bring both the range and median of the microgravity environment onto a single page for an entire mission or another time period or condition of interest. These single pages may then be used to compare similar analyses of other missions, time periods or conditions. The PCSA plot is based on the frequency distribution of the vibrational energy and is normally used for an acceleration data set containing frequencies above the lowest natural frequencies of the vehicle. The QTH plot is based on the direction and magnitude of the acceleration and is normally used for acceleration data sets with frequency content less than 0.1 Hz. Various operating conditions are made evident by using PCSA and QTH plots. Equipment operating either full or part time with sufficient magnitude to be considered a disturbance is very evident as well as equipment contributing to the background acceleration environment. A source's magnitude and/or frequency variability is also evident by the source's appearance on a PCSA plot. The PCSA and QTH techniques are valuable tools for extracting useful information from acceleration data taken over large spans of time. This report shows that these techniques provide a tool for comparison between different sets of microgravity acceleration data, for example different missions, different activities within a mission, and/or different attitudes within a mission. These techniques, as well as others, may be employed in order to derive useful information from acceleration data.Document ID19970016980Acquisition SourceLegacy CDMSDocument TypeTechnical Memorandum (TM)AuthorsDeLombard, Richard*(NASA Lewis Research Center Cleveland, OH United States)*McPherson, Kevin*(NASA Lewis Research Center Cleveland, OH United States)*Moskowitz, Milton*(Tal-Cut Co. North Olmstead, OH United States)*Hrovat, Ken*(Tal-Cut Co. North Olmstead, OH United States)*Date AcquiredSeptember 6, 2013Publication DateApril 1, 1997Subject CategorySpacecraft Propulsion And PowerReport/Patent NumberNASA-TM-107446NAS 1.15:107446E-10719Accession Number97N19348Funding Number(s)CONTRACT_GRANT: NAS3-27254PROJECT: RTOP 963-60-0DDistribution LimitsPublicCopyrightWork of the US Gov. Public Use Permitted.Available DownloadsNameType19970016980.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
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