The majority of Earth-based mammalian tissue and cell culture research is conducted in CO2 incubators where both the air temperature and carbon dioxide concentration are precisely controlled to ensure optimal and reproducible cell growth. CO2 serves the primary function of regulating culture pH through the bicarbonate buffering system employed by blood plasma and most culture media. This paper describes the design and performance of a CO2-control system that enables cell culture research onboard the ISS in combination with a temperaturecontrolled incubator. Precise on-orbit environmental control provides the basis for reproducible in-flight and ground experiments that can be directly compared to traditional terrestrial research literature. The on-orbit cell culture work is conducted using incubators developed by BioServe Space Technologies, a research center at the University of Colorado Boulder. The incubator platform, the Space Automated Bioproduct Lab (SABL), is a middeck locker size payload that controls its incubator chamber temperature to selectable setpoints between -5°C and +43°C with an accuracy of $pm$1°C or better. The Atmosphere Control Module (ACM) is a new science-specific insert designed to fit on the back wall of SABL's incubator chamber and to maintain the CO2 concentration within the chamber at a desired setpoint with $pm$0.5     «

The majority of Earth-based mammalian tissue and cell culture research is conducted in CO2 incubators where both the air temperature and carbon dioxide concentration are precisely controlled to ensure optimal and reproducible cell growth. CO2 serves the primary function of regulating culture pH through the bicarbonate buffering system employed by blood plasma and most culture media. This paper describes the design and performance of a CO2-control system that enables cell culture research onboard...     »