While the structural-dynamic mitigations being considered can assure that vibration due to TO is reduced to below the CxP crew health limit, it remains to be determined how far below this limit vibration must be reduced to enable effective crew performance during launch. Moreover, this “performance” vibration limit will inform the operations concepts (and crew-system interface designs) for this critical phase of flight. While Gemini and Apollo studies provide preliminary guidance, the data supporting the historical limits were obtained using less advanced interface technologies and very different operations concepts.

We performed two sets of studies. The first set dealt with display readability and has already been presented to the HRP community. In this poster, we present the second set, which deals with display usability. In the first study, Crew Office participants were asked to judge the degree of usability impairment as vibration ramped up and down. Three different display formats (Textual, 1-D Gauges, 2-D Graphics) were evaluated. In the second study, we studied whether judgments were impacted by vibration frequency and composition (i.e., a pure sine wave versus one with harmonic remnants).

The results from these empirical studies, coupled with the findings from the complementary studies on display readability, provide initial guidance for evaluating the display trade-space for Constellation vehicles and systems.

[Ed. note: added to Task Book September 2009]