Audible Noise Control for Columbus APM and the ECLS

The human engineering aspects for manned spacecraft systems, like the Columbus Attached Pressurized Module (APM) as part of the Space Station, request that the audible noise environment for the crew does not exceed certain specified limits. Airborne and structure-borne noise is generated in manned spacecraft systems by several sources and transmitted via a number of transmission paths into the habitable area. The Columbus APM system level audible noise control model is described. The air loops of the Environment Control and Life Support System (ECLS) form a group of major noise sources. The design implications and solutions selected for the ECLS subsystem are presented. A sound power flow model is used for system and subsystem design analysis and verification tasks. Preliminary results about the achievable audible noise environment are given.