NASA is currently using a solid amine sorbent known as HSC + for regeneratively removing CO 2 in space shuttle applications. This sorbent may also be of value for CO 2 removal in various industrial processes such as greenhouse gas control, industrial syntheses, and natural gas purification. To design novel sorbents and to design a CO 2 scrubber based on HSC + , physical and thermochemical property data are required. In this paper, we present a detailed experimental investigation of property data and long-term performance results using HSC + as a CO 2 sorbent. Differential scanning calorimetry was used to determine the heat capacity of the material. Cyclic and equilibrium capacities of the material for CO 2 pickup were determined and long-term test data show excellent performance. In addition, we have determined the heat of adsorption associated with CO 2 pickup by HSC + and the effect of moisture, using isothermal flow calorimetry. We have also performed thermal gravimetric analyses on the materials to gain insight into the stability of the material and determine the temperatures at which CO 2 and constituents of HSC + leave the surface of the material.