On the Shuttle, two radial flow beds containing 2.3 kg of granular LiOH (each) are used for CO2 control. The LiOH beds produce water so the LiOH bed is followed by a condensing heat exchanger. Lastly, there is a radial-flow ambient temperature catalytic oxidizer (ATCO) containing 0.32 kg of Pt-on-charcoal catalyst (see Fig. 3.2).