When astronauts get a shock

The Journal of the Acoustical Society of America, 1992

The aim of this work is to investigate the way in which sound is generated and radiated from supersonic jets. The work programme is essentially an experimental one using cold model air jets and has involved a study of the farfield and nearfield sound pressures. Also a relatively new optical technique 'The Crossed Beam Schlieren Apparatus'', is used t o obtain jet turbulence data. This is an important introduction to this field of work as prior to the development of optical probing techniques little information has been available in the correlation of flow fluctuations in supersonic jets , with their radiated sound characteristics.

The International Space Station (ISS) presents a significant acoustics challenge considering all of the modules and equipment that make it an on-orbit laboratory workshop and home with long-term crew occupation. This challenge is further complicated by the fact that there are numerous suppliers of ISS hardware, including the international partners. This paper addresses how ISS acoustics are managed to ensure a safe and habitable environment by establishing requirements, providing oversight and design support, sharing lessons learned and information, testing for hardware compliance, predicting future acoustic levels, and performing on-orbit measurements and monitoring of actual acoustic levels. ISS acoustic requirements are classified in three categories by the type of hardware involved: modules; payloads, and Government Furnished Equipment. The current status of overall ISS acoustics for each of these hardware categories will be discussed. In addition, examples will be discussed where NASA design support was used to aid in obtaining compliance, where difficulties were encountered, and where areas of concern were addressed.

Journal of Language, Speech and Swallowing Research, 2025

Introduction: This technical note highlights the significant advancements in space exploration by the Indian Space Research Organization, China National Space Administration and National Aeronautics and Space Administration. It delves into the challenges astronauts face in space, particularly regarding hearing, speech, language, communication, and swallowing, due to microgravity and other unique space environment factors. The crucial role of speech-language pathologists (SLPs) and audiologists in addressing these issues is underscored, emphasizing their involvement in astronaut training and the development of specialized protocols and communication methods suited for space conditions. Conclusion: The interdisciplinary collaboration among various professionals to support astronaut health and ensure mission success is discussed. As space missions extend in duration and ambition, the increasingly vital role of Audiologists and SLPs in overcoming the complex challenges of space travel is highlighted, marking an essential contribution to the safety and success of future explorations.

2005

Broadband shock noise was one of Shôn's work fields. Shôn has made important contributions to the acoustic analogy. Some recent papers were very critical with Lighthill's acoustic analogy. Broadband shock noise has gained renewed interest (fighter aircraft noise emission and cabin noise in cruise). Content of this presentation: It will be shown that broadband shock noise can be described with the acoustic analogy. A theory for broadband shock noise based on very simple turbulence models is presented. Results will be compared with new experimental data on broadband shock noise. Broadband shock noise described with the acoustic analogy 3

Acoustics Today, 2009

Shock Waves, 1992

Shock waves generated by the space shuttles Columbia (August 13, 1989), Atlantis (April 11, 1991) and Discovery (September 18, 1991) on their return to Edwards Air Force Base, California, were recorded by TERRAscope (Caltech's broadband seismic network), the Caltech-U.S.G.S Southern California Seismic Network (SCSN), and the University of Southern California (USC) Los Angeles Basin Seismic Network. The spatial pattern of the arrival times exhibits hyperbolic shock fronts from which the path, velocity and altitude of the space shuttle could be determined. The shock wave was acoustically coupled to the ground, converted to a seismic wave, and recorded clearly at the broadband TERRAscope stations. The acoustic coupling occurred very differently depending on the conditions of the Earth's surface surrounding the station. For a seismic station located on hard bedrock, the shock wave (N wave) was clearly recorded with little distortion. Aside from the N wave, very little acoustic coupling of the shock wave energy to the ground occurred at these sites. The observed N wave record was used to estimate the overpressure of the shock wave accurately; a pressure change of 0.5 to 2.2 mbars was obtained. For a seismic station located close to the ocean or soft sedimentary basins, a significant amount of shock wave energy was transferred to the ground through acoustic coupling of the shock wave and the oceanic Rayleigh wave. A distinct topography such as a mountain range was found effective to couple the shock wave energy to the ground. Shock wave energy was also coupled to the ground very effectively through large man made structures such as high rise buildings and offshore oil drilling platforms. For the space shuttle Columbia, in particular, a distinct pulse having a period of about 2 to 3 seconds was observed, 12.5 s before the shock wave, with a broadband seismograph in Pasadena, This pulse was probably excited by the high rise buildings in downtown Los Angeles which were simultaneously hit by the space shuttle shock waves. The proximity of the natural periods of the high rise buildings and the modal periods of the Los Angeles basin enabled efficient energy transfer from shock wave to seismic wave.

10th Aeroacoustics Conference, 1986

An analytical procedure has k e n developed to study mise generation in a double wall and single wall cylindrical shell due to mchanical point loads. theoretical procedures for parmtric evaluation of mise generation and noise transmission for the habitability modules of the proposed Space Station operation. acousticstructural equations are obtained utilizing modal decompositon. m e numerical results include modal frequencies, deflection response spectral densities and interior noise sound pressure levels.

The Journal of the Acoustical Society of America, 2006

This monograph reviews current knowledge in the design of auditory caution and warning signals, and sets criteria for development of 'best practices' for designing new signals for NASA's Crew Exploration Vehicle (CEV) and other future spacecraft, as well as for extra-vehicular operations. A design approach is presented that is based upon cross-disciplinary examination of psychoacoustic research, human factors experience, aerospace practices, and acoustical engineering requirements. Existing alarms currently in use with the NASA Space Shuttle flight deck are analyzed and then alternative designs are proposed that are compliant with ISO 7731, "Danger signals for work places-Auditory Danger Signals", and that correspond to suggested methods in the literature to insure discrimination and audibility. Future development of auditory "sonification" techniques into the design of alarms will allow auditory signals to be extremely subtle, yet extremely useful for indicating trends or root causes of failures. A summary of 'best practice' engineering guidelines is given, followed by results of an experiment involving subjective classification of alarms by ten subjects.