Showing papers by "William H. Prosser published in 2009"

Thermal Protection System Monitoring of Space Structures

Abstract: The loss of the space shuttle Columbia, as a result of impact damage from foam debris during ascent, led NASA to develop and implement onboard impact-detection technologies. Acoustic emission sensing, both with accelerometers and ultrasonic sensors, was used to monitor a wide variety of impact conditions on space shuttle components ranging from insulating foam and ablator materials, and ice at ascent velocities to simulated hypervelocity micrometeoroid and orbital debris impacts. Impact testing was performed on both reinforced carbon composite wing leading-edge materials and shuttle tile materials on representative aluminum wing structures. Results of these impact tests are presented with a focus on the acoustic emission sensor responses to these impact conditions. These tests demonstrated the potential for onboard shuttle impact detection and led to the development and implementation of the shuttle wing leading-edge impact-detection system (WLEIDS). The WLEIDS has been installed on all space shuttles and has been monitored on all flights since the Columbia. Results from the WLEIDS are discussed. Keywords: impact detection; acoustic monitoring; space shuttle; thermal protection system; reinforced carbon–carbon