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Effects of Transverse Seat Vibration on Near-Viewing Readability of Alphanumeric Symbology  (2009)
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We measured the impacts on human visual function of a range of vibration levels (0.15, 0.3, 0.5, and 0.7 g) at the frequency and along the axis of the anticipated Ares thrust oscillation. We found statistically significant and equivalent decrements in performance on a reading and a numeric processing task at tested vibration levels above 0.3 g (0-to-peak), but no evidence of aftereffects. At the smallest font and highest vibration level tested, the average effect was a 50% increase in response time and six-fold increase in errors. Our findings support a preliminary trade space in which currently planned Orion font sizes and text spacing appear to be too small to support accurate and efficient reading at the tested vibration levels above 0.3 g, but not too small to support reading at 0.3 g. This study does not address potential impacts on crew cognitive decision-making or motor control and does not test either the full induced Orion-Ares environment with its sustained Gx-loading or the full complexity of the final Orion seat-helmet-suit interface. A final determination of the Orion-Ares program limit on vibration must take these additional factors into consideration and, thus, may need to be lower than that needed to support effective reading at 1-Gx bias.
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Alphanumeric, Effects, Near-Viewing, Readability, Seat, Symbology, Transvers, Vibration
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NASA Technical Memorandum 2009-215385
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Adobe PDF Icon  NASA_TM-2009-215385.pdf (Download Acrobat Reader Click to download Adobe Acrabat Reader)
  (1997KB) (application/pdf)
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Curator: Phil So
NASA Official: Jessica Nowinski
Last Updated: August 15, 2019