Browsing by Author "Allen, Chris"
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Item International Space Station (ISS) Crewmember’s Noise Exposures from 2015 to Present(47th International Conference on Environmental Systems, 2017-07-16) Limardo, Jose; Allen, Chris; Danielson, Richard W.Noise has been an enduring environmental physical hazard that has challenged the U.S. space programs since before the Apollo program. During long-duration missions on the International Space Station (ISS), noise exposures from onboard equipment and crew activities are posing concerns for human factors, human performance and crew health. According to acoustic dosimetry data collected to date, NASA’s stringent noise hazard exposure limits; (based on World Health Organization guidelines), have been exceeded approximately 45% of the time since ISS increment 17 (2008), with undefined impacts on crew. This measure does not take into account the effects of any hearing protection devices (HPDs) worn by the crew, as the dosimeter microphones are attached to the crew’s collars. The crew are instructed to wear HPDs as an operational control when exposed to known hazardous noise sources, and when they feel the noise levels are high. It is still crucial to control noise aboard ISS to acceptable noise levels during the work-time period, and also to provide a restful sleep environment during the sleep-time period. The purpose of this paper is to provide an update on crew noise exposure monitoring data collected since May 2015 (ISS Increment 43) and also to compare data to previous reporting periods. A review of NASA’s noise level constraints flight rule will be briefly described, as well as our Noise Exposure Estimation Tool and Noise Hazard Inventory implementation. Future acoustics research will aim to relate ISS noise exposures to auditory and non-auditory health effects, especially how acoustic conditions can affect hearing sensitivity, human performance, sleep, and crew health on the ISS.Item International Space Station Acoustics – A Status Report(2024 International Conference on Environmnetal Systems, 2024-07-21) Allen, ChrisIt is important to control acoustical noise aboard the International Space Station (ISS) to provide a satisfactory environment for voice communications, alarm audibility, and restful sleep, and to minimize the risk for hearing loss. Acoustic monitoring is an important part of the noise control process on ISS, providing critical data for trend analysis, noise exposure analysis, and validation of acoustic analyses and predictions. This data is also used to provide strong evidence for ensuring crew health and safety, thus allowing Flight Certification. And since the primary noise sources on ISS include the environmental control and life support system�s air revitalization system (fans and airflow) and active thermal control system (pumps and water flow), acoustic monitoring will indicate changes in hardware noise emissions that may indicate system degradation or performance issues. This paper provides the current acoustic levels in the ISS modules and sleep stations, and is an update to the status presented in 2018. Since the last status report, the speed of the Common Cabin Air Assembly air conditioning fan and the speed of the Pump Package Assembly cooling water pump have been increased in the US Laboratory module. And in the Node 3 module, the T2 treadmill has been replaced with a new quieter serial unit. Also, a significant number of science experiments have been added to the Japanese Experiment Module. This paper will present the acoustic levels resulting from these changes. Finally, a new type of sound level meter is being used for the noise surveys. This new Acoustic Monitor has additional capabilities, allowing for narrow-band and other analyses of the on-orbit measurements and also allowing for more-frequent measurement activities. Benefits of this new measurement hardware will be discussed.Item NASA Environmental Control and Life Support Technology Development for Exploration: 2022-2023 Status(2023 International Conference on Environmental Systems, 2023-07-16) Schneider, Walter; Brown, Arthur; Allen, Chris; Barta, Daniel; Gazda, Daniel; McKinley, Melissa; Ridley, Alesha; Stambaugh, ImeldaNASA is pursing Environmental Control and Life Support technology developments and hardware upgrades to support Gateway, lunar surface, Mars transit, and Mars surface missions. This paper will highlight 2022-2023 progress of the technologies and how they are maturing on the path to ground testing and demonstration in microgravity. Technologies NASA is trading, new developments, and particular challenging issues will be highlighted. Technologies addressed in this paper are in the areas of atmosphere revitalization, water recovery and management, waste management, and environmental monitoring.