Accumulation and subsequent compression of carbon dioxide that is removed from the space cabin are two important processes involved in a closed-loop air revitalization scheme of the International Space Station (ISS). The 4-Bed Molecular Sieve (4BMS) of ISS currently operates in an open loop mode without a compressor. This paper reports the integrated 4BMS and liquid-cooled Temperature Swing Adsorption Compressor (TSAC) testing conducted during the period of March 3 to April 18, 2003. The TSAC prototype was developed at NASA Ames Research Center (ARC)1. The 4BMS was modified to a functionally flight-like condition at NASA Marshall Space Flight Center (MSFC)2. Testing was conducted at MSFC. The paper provides details of the TSAC operation at various CO2 loadings and corresponding performance of the 4BMS.