A study was initiated to investigate the potential of integrating a membrane gas separation unit into the Space Station Atmosphere Revitalization Subsystem to remove inert impurities in the carbon dioxide stream fed to the Bosch reduction reactor. Removal of the inerts eliminates the need for a reactor bleed stream and subsequent treatment. Preliminary calculations indicate that under normal operating conditions, inclusion of the membrane unit reduces Atmosphere Revitalization power consumption and heat rejection by 388 and 300 watts, respectively, and causes only small weight and space penalties to be incurred. According to current cost factors, an annual net savings of $0.76 million (in 1989 dollars) excluding separator hardware costs is realized. Although based on preliminary data and estimates, there appears to be reasons for cautious optimism in the proposed design modification and continuation of the study to obtain more detailed data.